Ice NP900 Series Application Manual

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Page 2 Electrical equipment should be installed, operated, serviced, and maintained only by qualified personnel. Local safety regulations should be followed. No responsibility is assumed by ICE for any consequences arising out of the use of this material. We reserve right to changes without further notice.
Page 3: Table Of Contents
Application Guide - NP900 Series 3 (504 TABLE OF CONTENTS 1 ABBREVIATIONS ......................5 2 GENERAL ......................... 6 3 FUNCTIONS OF NP900....................7 Measurements ....................... 7 3.1.1 Current measurement and scaling ..............7 3.1.2 Voltage measurement and scaling .............. 20 3.1.3 Frequency tracking and sampling ...............
Page 4 Application Guide - NP900 Series 4 (504 3.3.3 Motor start / locked rotor monitoring (LRC) I > (48, 14) ......255 3.3.4 Frequent start protection (FSP) N> (66) ............ 265 3.3.5 Under current I< (37) ................270 3.3.6 Mechanical jam protection I >...
Page 5: Abbreviations
Application Guide - NP900 Series 5 (504 BBREVIATIONS CB – Circuit breaker CBFP – Circuit breaker failure protection CT – Current transformer CPU – Central processing unit EMC – Electromagnetic compatibility HMI – Human machine interface HW – Hardware IED – Intelligent electronic device IO –...
Page 6: General
ICE demonstrates via its accomplishments in the field of industrial reliability how it can apply its technologies to the other fields of the electrical energy...
Page 7: Functions Of Np900
For the measurements to be correct it is essential to understand the concept of the NP900 series IEDs current measurements.
Page 8 (This is not absolutely mandatory, in some relays it is still needed to calculate correct settings manually. Setting the relay nominal current makes the motor protection a lot easier and straight forward. In modern protection IED like NP900 series devices this scaling calculation is done internally after the current transformer primary, secondary and motor nominal currents are given).
Page 9 Application Guide - NP900 Series 9 (504 Figure 3.1.1.1-2 Example connection. Initial data of the connection and the ratings are presented in following table. Table 3.1.1.1-1 Initial data from example connection. Phase current CT: Ring core CT in Input I02:...
Page 10 Application Guide - NP900 Series 10 (504 Figure 3.1.1.1-3 Phase current transformer scalings to CT nominal. After the settings are input to the IED, scaling factors are also calculated and displayed for the user. Scaling factor P/S tells the CT primary to secondary ratio, CT scaling factor to NOM tells the scaling factor to nominal current (in this case it should be 1 since the selected nominal current is the phase CT nominal).
Page 11 Application Guide - NP900 Series 11 (504 the used scaling factors can now be seen. Primary to secondary ratio is directly the ratio of the set CT ratios, CT scaling factor to nominal is now the set CT primary to nominal...
Page 12 Application Guide - NP900 Series 12 (504 Figure 3.1.1.1-8 Scalings to protected object nominal current. As seen from the examples the primary and secondary currents will be displayed as actual values so the scaling selection does not have effect to that. Only effect is now that the per unit system in the relay is scaled to either transformer nominal or the protected object nominal and this makes the settings input for the protected object straight forward.
Page 13 Application Guide - NP900 Series 13 (504 Figure 3.1.1.2-10 Setting example of zero sequence current transformer application. Figure 3.1.1.2-11 With current transformer ratio of 200mA/1.5mA earthfault protection setting 1*I0n will make the function pick-up at 200mA primary current. 3.1.1.3 T ROUBLESHOOTING It is possible that for some reason the measured currents may not be as expected.
Page 14 Application Guide - NP900 Series 14 (504 Phase unbalance protection trips immediately when it incorrect. is activated. Go to Measurement, Phasors and check the current Earth fault protection trips immediately when it is Phasors diagram. activated. When all is correctly connected the diagram should...
Page 15 Application Guide - NP900 Series 15 (504 Network rotation / mixed phases problem might be difficult to find since the measurement result shall always be the same in the relay. If two phases are mixed together the network rotation shall always look like IL1-IL3-IL2 and the measured negative sequence current shall be always 1.00 per unit if this is the case.
Page 16 Application Guide - NP900 Series 16 (504 connector 1 to connector 2 and the secondary currents starpoint is towards line. IL2 Polarity IL2 (second current) measurement 1:Invert channel polarity (direction) selection. Default setting is that positive current flow is from connector 3 to connector 4 and the secondary currents starpoint is towards line.
Page 17 Application Guide - NP900 Series 17 (504 3.1.1.5 M EASUREMENTS Following measurements are available from the measured current channels. Table 3.1.1.5-5 Per unit phase current measurements in NP900. Name Range Step Description Phase current ILx 0.00…1250.0 xIn 0.01xIn Per unit measurement from each phase current channel fundamental frequency RMS current.
Page 18 Application Guide - NP900 Series 18 (504 Table 3.1.1.5-9 Per unit residual current measurements in NP900. Name Range Step Description Residual current I01 0.00…1250.0 xIn 0.01xIn Per unit measurement from residual current channel I01 fundamental frequency RMS current. Residual current I02 0.00…1250.0 xIn...
Page 19 Application Guide - NP900 Series 19 (504 Table 3.1.1.5-11 Secondary residual current measurements in NP900. Name Range Step Description Secondary residual 0.00…300.0A 0.01A Secondary measurement from residual current I01 current channel I01 fundamental frequency RMS current. Secondary residual 0.00…300.0A 0.01A...
Page 20: Voltage Measurement And Scaling
I02 3.1.2 V OLTAGE MEASUREMENT AND SCALING In NP900 series voltage measurement module (VT-module) is used for measuring the voltages from voltage transformers and processing the measured voltages to measurement database and for use of measurement- and protection functions (protection function availability depends on IED type).
Page 21 “know” primary and per unit values it needs to be set the voltage transformer rated primary and secondary voltages. In modern IEDs like NP900 series devices the scaling calculation is done internally after the voltage transformer primary and secondary voltages are given.
Page 22 Application Guide - NP900 Series 22 (504 Figure 3.1.2.1-13 Example connection with three line to neutral voltages and zero sequence voltage connected. 3LN+U4 mode has to be selected. U4 channel has to be set as U0. Initial data of the connection and the ratings are presented in following table.
Page 23 Application Guide - NP900 Series 23 (504 Figure 3.1.2.1-14 Voltage may be based on line to line voltage or line to neutral voltage. This selection is completed in “Measured magnitude” –menu under each voltage protection stage separately. Availability of protection functions depends on IED type.
Page 24 Application Guide - NP900 Series 24 (504 3LN+U4 • 3LL+U4 • 2LL+U3+U4 • See below connection wirings for 3LL and 2LL connections. Figure 3.1.2.1-16 Example connections for voltage line to line measurement. Three line- to line voltages on the left and two on the right.
Page 25 Application Guide - NP900 Series 25 (504 Figure 3.1.2.1-17 Two line to line measurements with zero sequence voltage and voltage from side 2 for Synchro-check 2LL+U0+SS. Line to neutral voltages can be calculated since U0 is available. In the next figure is presented relay behavior when nominal voltage is injected to the relay and the IED is measuring line to neutral voltages.
Page 26 Application Guide - NP900 Series 26 (504 Figure 3.1.2.1-19 Voltage injection during earth fault to the IED by using secondary test equipment. Voltage transformer scaling is set to 20000:100 V. Voltage measurement mode is 3LN+U4 and U4 channel is measuring zero sequence voltage which has same ratio 20000:100 V.
Page 27 Application Guide - NP900 Series 27 (504 3.1.2.3 S ETTINGS Table 3.1.2.3-19 Settings of the VT scaling in NP900. Name Range Step Default Description Voltage meas mode 0:3LN+U4 0:3LN+U4 Voltage wiring method to the IED. 1:3LL+U4 Voltages are scaled according the set 2:2LL+U3+U4 voltage measurement mode.
Page 28 Application Guide - NP900 Series 28 (504 scaling factor for primary /secondary voltage ratio VT scaling factor p.u. IED feedback value, scaling factor from p.u. value to primary voltage. VT scaling factor p.u. IED feedback value, scaling factor from p.u. value to secondary voltage.
Page 29 Application Guide - NP900 Series 29 (504 Table 3.1.2.4-22 Voltage phase angle measurements in NP900. Name Range Step Description Ux Angle 0.00…360.00 deg 0.01deg Phase angle measurement of the four voltage inputs. Table 3.1.2.4-23 Per unit sequence voltage measurements in NP900.
Page 30 Application Guide - NP900 Series 30 (504 Table 3.1.2.4-27 Primary voltage measurements in NP900. Name Range Step Description System volt UL12 mag 0.00…1000000.00V 0.01V Primary measured or calculated fundamental frequency RMS line to line UL12 voltage. System volt UL23 mag 0.00…1000000.00V...
Page 31: Frequency Tracking And Sampling
3.1.3 F REQUENCY TRACKING AND SAMPLING In NP900 series the measurement sampling can be set to frequency tracking mode or fixed user given frequency sampling mode. Benefit of the frequency tracking is that the measurements are in given accuracy range even when the fundamental frequency of the power system changes.
Page 32 For this reason the magnitude and angle measurements need to be calibrated against frequency. For this purpose measured channels FFT result fundamental frequency component is corrected for magnitude and angle errors by ICE NP900 series patented calibration algorithms. 3.1.3.1 T ROUBLESHOOTING It is possible that for some reason the measured currents may not be as expected.
Page 33 Application Guide - NP900 Series 33 (504 3.1.3.2 S ETTINGS Table 3.1.3.2-30 Settings of the frequency tracking in NP900. Name Range Step Default Description Sampling mode 0:Fixed 0:Fixed Selection of the IED measurement 1:Tracking sampling mode either fixed user settable...
Page 34: Power And Energy Calculation
3.1.4 P OWER AND ENERGY CALCULATION NP900 series IEDs with both voltage –and current cards can calculate power and have power based protection and monitoring functions depending on the IED type. When power calculation is possible also the energy magnitudes are calculated.
Page 35 Below is presented formula for three phase reactive power (Q) calculation: × I sin φ × I sin φ Where, × I sin φ UL1…UL3 = Line to neutral voltage Q = Q IL1…IL3 = Phase current φ Angle difference between voltage and current Active power direction can be to forward or reverse direction.
Page 36 Application Guide - NP900 Series 36 (504 NLY LINE TO LINE VOLTAGES AVAILABLE In case the line to line voltages are measured and zero sequence voltage is not measured and known the three phase power calculation is based on Aaron’s theorem: S = U ×...
Page 37 Application Guide - NP900 Series 37 (504 Table 3.1.4.2-32 Energy Dose Counter 1 settings in NP900. Name Range Step Default Description Energy dose 0:Disabled 0:Disabled Enable energy dose counters counter mode 1:Activated generally. DC 1…4 enable 0:Disabled 0:Disabled Enable energy dose counter 1:Enabled 1…4 individually.
Page 38 Application Guide - NP900 Series 38 (504 Table 3.1.4.3-36 Phase L2 power calculation in NP900. Name Range Step Description L2 Apparent power (S) -1x10 …1x10 0.01kVA Phase L2 apparent power L2 Active power (P) -1x10 …1x10 0.01kW Phase L2 active power...
Page 39 Application Guide - NP900 Series 39 (504 Table 3.1.4.4-39 Phase L1 energy calculation in NP900. Name Range Step Description L1 Exp.Active Energy Mwh -1x10 …1x10 0.01MWh Phase L1 exported active energy L1 Imp.Active Energy Mwh -1x10 …1x10 0.01MWh Phase L1 imported active energy L1 Exp/Imp.Act.E balance...
Page 40 Application Guide - NP900 Series 40 (504 Table 3.1.4.4-41 Phase L3 energy calculation in NP900. Name Range Step Description L3 Exp.Active Energy Mwh -1x10 …1x10 0.01MWh Phase L3 exported active energy L3 Imp.Active Energy Mwh -1x10 …1x10 0.01MWh Phase L3 imported active energy L3 Exp/Imp.Act.E balance...
Page 41 Application Guide - NP900 Series 41 (504 Name Name Name Name L1 (S) 4.08 L2 (S) 6.15 L3 (S) 9.77 3PH (S) 20.00 L1 (P) 2.89 L2 (P) 4.72 L3 (P) 9.71 3PH (P) 17.32 L1 (Q) 2.89 L2 (Q) -3.94...
Page 42: Protection Functions
Application Guide - NP900 Series 42 (504 3.2 P ROTECTION FUNCTIONS 3.2.1 G ENERAL PROPERTIES OF A PROTECTION FUNCTION In following flowchart is described the basic structure of any protection function. Basic structure is composed of the analog measurement values comparison to the pick-up values and operating time characteristics.
Page 43 Application Guide - NP900 Series 43 (504 Protection function is run in a completely digital environment with protection CPU microprocessor which also processes the analog signals transferred to digital form. Figure 3.2.1-21 Principle diagram of NP900 protection relay platform. In following chapters are presented the common functionalities of protection functions. If in some protection function is deviation of this basic structure the difference is described in the corresponding chapter of the manual.
Page 44 Application Guide - NP900 Series 44 (504 Figure 3.2.1.1-22 Pick up and reset characteristics of the function. The pick-up activation of the function is not directly equal to start-signal generation of the function. Start signal is allowed if blocking condition is not active.
Page 45 Application Guide - NP900 Series 45 (504 secondary currents from 0.001A up to 250A. To this relation the pick-up setting in secondary amperes will vary. 3.2.1.2 F UNCTION BLOCKING In the blocking element the block signal is checked in the beginning of each program cycle.
Page 46 Application Guide - NP900 Series 46 (504 Figure 3.2.1.3-24 Definite (Min) Operating Time Delay determines the minimum operating time delay. When using only IDMT it is possible to disable minimum operating time delay by setting this parameter to zero. In the table below are presented the setting parameters for the function time characteristics.
Page 47 Application Guide - NP900 Series 47 (504 Delay curve series Setting is active and visible when Delay IEEE Type is selected to IDMT. Delay curve series for IDMT operation following either IEC or IEEE/ANSI standard defined characteristics. Delay Setting is active and visible when Delay characteristics Type is selected to IDMT.
Page 48 Application Guide - NP900 Series 48 (504 Table 3.2.1.3-43 Inverse operating time formulas. IEEE/ANSI             −             −...
Page 49 Application Guide - NP900 Series 49 (504 Figure 3.2.1.3-25. Definite time operating characteristics. A996A...
Page 50 Application Guide - NP900 Series 50 (504 Figure 3.2.1.3-26. IEC predefined characteristics NI, VI, LTI and EI A996A...
Page 51 Application Guide - NP900 Series 51 (504 Figure 3.2.1.3-27. IEEE ANSI predefined characteristics EI, LTI, NI and VI A996A...
Page 52 Application Guide - NP900 Series 52 (504 Figure 3.2.1.3-28. IEEE predefined characteristics EI, MI and VI A996A...
Page 53 Application Guide - NP900 Series 53 (504 Figure 3.2.1.3-29. Parameters A, B and C effect to the characteristics. A996A...
Page 54 Application Guide - NP900 Series 54 (504 3.2.1.4 N STANDARD DELAY CHARACTERISTICS Additionally to previously mentioned delay characteristics some functions also have delay characteristics that deviate from the norm. These functions are Overcurrent stages, Residual overcurrent stages, Directional overcurrent stages and Directional residual overcurrent stages.
Page 55 Application Guide - NP900 Series 55 (504 Table 3.2.1.4-44 Reset time characteristics setting parameters. Release Time 0.000…150.000 s 0.005 s 0.06 s Resetting time. Time allowed in between delay of pick-ups if the pick-up has not lead into trip operation. During this time the start signal is held on for the timers if delayed pick-up release is active.
Page 56 Application Guide - NP900 Series 56 (504 Figure 3.2.1.4-31. Delayed pick-up release, delay counter is reset at signal drop-off. Figure 3.2.1.4-32. Delayed pick-up release, delay counter value is held during the release time. A996A...
Page 57 3.2.1.5 S TAGE FORCING In NP900 series relays it is possible to test the logic and the operation of the protection system of the relay by controlling the state of the protection functions by hand without Enable stage forcing injecting any current into the relay.
Page 58: Non-Directional Over Current I> (50/51)
Application Guide - NP900 Series 58 (504 3.2.2 N I> (50/51) DIRECTIONAL OVER CURRENT Overcurrent function (NOC) is used for non-directional instant- and time delayed overcurrent/short circuit protection for various applications including feeder, filter and machine applications of utilities and industry. The number of available instances of the function depends of the IED model.
Page 59 Application Guide - NP900 Series 59 (504 Figure 3.2.2-34 Simplified function block diagram of the NOC function. 3.2.2.1 M EASURED INPUT VALUES Function block uses analog current measurement values. Function block always utilizes peak-to-peak measurement from samples and by user selection the monitored magnitude can be either fundamental frequency RMS values, True RMS values from the whole harmonic specter of 32 components or peak to peak values.
Page 60 Application Guide - NP900 Series 60 (504 3.2.2.2 P UP CHARACTERISTICS Iset Pick-up of the NOC function is controlled by setting parameter, which defines the maximum allowed measured current before action from the function. The function constantly calculates the ratio in between of the Iset and measured magnitude (Im) per all Iset three phases.
Page 61 Application Guide - NP900 Series 61 (504 3.2.2.4 O PERATING TIME CHARACTERISTICS FOR TRIP AND RESET The operating timers’ behavior of the function can be set for trip signal and also for the release of the function in case the pick-up element is reset before the trip time has been reached.
Page 62 Application Guide - NP900 Series 62 (504 mentioned here. Delay ANSI NI Setting is active and visible when Delay characteristics ANSI VI Type is selected to IDMT. IEEE ANSI EI IEEE and ANSI standard delay ANSI LI characteristics. ANSI: Normal Inverse,...
Page 63 Application Guide - NP900 Series 63 (504 Resetting characteristics can be set according to the application. Default setting is delayed with 60 ms and the time calculation is held during the release time. When using the release delay option where the operating time counter is calculating the operating time during the release time, function will not trip if the input signal is not activated again during the release time counting.
Page 64: Non-Directional Earth Fault I0> (50N/51N)
Application Guide - NP900 Series 64 (504 Date & Time Event Fault Trigger Fault Prefault Trip time Used code type current current current remaining dd.mm.yyyy 1280- L1-G… Start Trip Start 0 ms - 1 - 8 hh:mm:ss.mss 1477 L1-L2- average...
Page 65 Application Guide - NP900 Series 65 (504 common event buffer from each of the three output signal. In instant operating mode the function outputs START and TRIP events simultaneously with equivalent time stamp. Time stamp resolution is 1ms. Function provides also cumulative counters for START, TRIP and BLOCKED events.
Page 66 Application Guide - NP900 Series 66 (504 Table 3.2.3.1-51 Analogic magnitudes used by the NEF function. Signal Description Time base I01PP Peak-to-peak measurement of coarse residual current 5 ms measurement input I01 I01RMS Fundamental RMS measurement of coarse residual current...
Page 67 Application Guide - NP900 Series 67 (504 3.2.3.3 F UNCTION BLOCKING In the blocking element the block signal is checked in the beginning of each program cycle. Blocking signal is received from the blocking matrix for the function dedicated input.
Page 68: Directional Over Current Idir> (67)
Application Guide - NP900 Series 68 (504 Table 3.2.3.5-53. Event codes of the NEF-function instances 1 – 4. Event Event Event Event Number channel Event block name Code Description Type 1664 26 NEF1 0 Start ON 1665 26 NEF1 1 Start OFF...
Page 69 Application Guide - NP900 Series 69 (504 signal and setting group selection controls the operating characteristics of the function during normal operation. Outputs of the function are Start Trip and Blocked signals. Setting parameters are static inputs for the function which are changed only by user input in the setup phase of the function.
Page 70 Application Guide - NP900 Series 70 (504 Figure 3.2.4-36 Simplified function block diagram of the DOC function. 3.2.4.1 M EASURED INPUT VALUES Function block uses analog current measurement values. Function block always utilizes peak-to-peak measurement from samples and by user selection the monitored magnitude can be either fundamental frequency RMS values, True RMS values from the whole harmonic specter of 32 components or peak to peak values.
Page 71 Application Guide - NP900 Series 71 (504 Table 3.2.4.1-55 Analogic magnitudes used by the DOC function. Signal Description Time base IL1PP Peak-to-peak measurement of phase L1/A current 5 ms IL2PP Peak-to-peak measurement of phase L2/B current 5 ms IL3PP Peak-to-peak measurement of phase L3/C current...
Page 72 Application Guide - NP900 Series 72 (504 value. The setting value is common for all measured phases and single-, dual- or all phases Im exceed of the Iset value will cause pick-up operation of the function. The fault has to be in the monitored direction as well to fulfill the terms to trip. Fault direction can be set to forward or reverse.
Page 73 Application Guide - NP900 Series 73 (504 Notice in picture above that tripping area is linked to the angle of positive sequence voltage U1. Positive sequence current I1 angle is compared to U1 angle and in case the fault is in correct direction it is possible to perform trip when amplitude of I or I increases above the pick-up limit.
Page 74 Application Guide - NP900 Series 74 (504 DOC function offers four independent instances which events are segregated for each instance operation. In the function is available 12 last registers where the triggering event of the function (start, trip or blocked) is recorded with time stamp and process data values.
Page 75: Directional Earth Fault I0Dir> (67N)
Application Guide - NP900 Series 75 (504 3.2.5 D > (67N) IRECTIONAL EARTH FAULT Directional earth fault function (DEF) is used for instant- and time delayed earth fault protection for various applications including feeder and machine applications of utilities and industry. IED with both voltage and current protection module may have four available instances of the function (I0Dir>, I0Dir>>, I0Dir>>>, I0Dir>>>>).
Page 76 Application Guide - NP900 Series 76 (504 Figure 3.2.5-38 Simplified function block diagram of the DEF function. 3.2.5.1 EASURED INPUT VALUES Function block uses analog current measurement values. Function block always utilizes peak-to-peak measurement from samples and by user selection the monitored magnitude can be either fundamental frequency RMS values, True RMS values from the whole harmonic specter of 32 components or peak to peak values.
Page 77 Application Guide - NP900 Series 77 (504 measurement input I01 I02PP Peak-to-peak measurement of sensitive residual current 5 ms measurement input I02 I02RMS Fundamental RMS measurement of sensitive residual 5 ms current measurement input I02 I02TRMS TRMS measurement of coarse sensitive current...
Page 78 Application Guide - NP900 Series 78 (504 network) Angle Io angle blinder -90.0…0.0° 0.1° -90° blinder (Petersen coil grounded) The pick-up activation of the function is not directly equal to start-signal generation of the function. Start signal is allowed if blocking condition is not active.
Page 79 Application Guide - NP900 Series 79 (504 ETERSEN COIL GROUNDED COMPENSATED NETWORK There are many benefits with Petersen coil grounded network. Amount of automatic reclosing is highly decreased and therefore maintenance of breakers is diminished. Arc faults die on their own and cables and equipment suffer less damage. In emergency situations line with earth fault can be used for certain time.
Page 80 Application Guide - NP900 Series 80 (504 IRECTLY OR SMALL IMPEDANCE GROUNDED NETWORK F1 current F2 current Figure 3.2.5.2-41 Angle tracking of DEF function. Petersen coil grounded network model. In directly grounded network the amplitude of single phase fault current is similar to amplitude of short circuit current.
Page 81 Application Guide - NP900 Series 81 (504 3.2.5.3 R TIME INFO DISPLAYED OF THE FUNCTION The relays Info-page displays useful information in real time of the state of the protection function either through relays HMI display or with SMART9 software when connection there is a connection to relay and Live Edit-mode is activated.
Page 82 Application Guide - NP900 Series 82 (504 3.2.5.5 O PERATING TIME CHARACTERISTICS FOR TRIP AND RESET This function supports definite time delay (DT) and inverse definite minimum time (IDMT) delay types. For detailed information on these delay types refer to chapter General properties of a protection function.
Page 83: Intermittent Earth Fault I0Int> (67Nt)
Application Guide - NP900 Series 83 (504 Event Code dd.mm.yyyy hh:mm:ss.mss Date & Time 5184-5381 Descr. Io pretriggering current Start average current Io fault current Trip -20ms averages Fault capacity Io Trip -20ms averages Fault resist Io Trip -20ms averages...
Page 84 Application Guide - NP900 Series 84 (504 incomer. This is typical behavior in old-fashioned relay protection which is not capable to differentiate in between of normal consistent earth fault and intermittent earth fault. Since the intermittent earth fault is transient type of fault where the actual fault is only few hundred microseconds causes the traditional directional earth fault protection relays to lose the directional sensitivity.
Page 85 Application Guide - NP900 Series 85 (504 Figure 3.2.6-42 Close to resonance tuned medium size network intermittent earth fault seen by faulty feeder relay. Figure 3.2.6-43 Close to resonance tuned network intermittent earth fault seen by healthy feeder relay. A996A...
Page 86 Application Guide - NP900 Series 86 (504 Figure 3.2.6-44 Undercompensated medium size network intermittent earth fault seen by faulty feeder relay. Figure 3.2.6-45 Undercompensated medium size network intermittent earth fault seen by healthy feeder relay. As can be seen from the figures the residual voltage in both cases is high. When...
Page 87 Application Guide - NP900 Series 87 (504 most probably directional earth fault may not even pick-up and if it picks up it will surely release before set operating time. Residual voltage still stays on for longer period and most probably in this case it will also release before the set tripping time. This situation may last for long time and cause stress to the network unnecessarily and if let to last long may cause insulator breakdown in other parts of the network.
Page 88 Application Guide - NP900 Series 88 (504 can be stated that the reset time of an intermittent earth fault stage should not be set lower than 450ms to obtain a network independent setting. Using this reset set value one can be sure that function will not reset too early even in resonance tuned network.
Page 89 Application Guide - NP900 Series 89 (504 It is also important to check that the reset time settings are never set longer than the desired operating time delay setting. 3.2.6.3 M EASURED INPUT VALUES For the function block is used analog current measurement values from the residual magnitudes.
Page 90 Application Guide - NP900 Series 90 (504 If blocking signal is active when pick-up element activates a BLOCKED signal will be generated and the function shall not process the situation further. If START function has been activated before blocking signal it will reset and the release time characteristics are processed as in case of when pick-up signal is reset.
Page 91 Application Guide - NP900 Series 91 (504 Table 3.2.6.6-65 Operating time characteristics setting parameters. Name Range Step Default Description FWD reset time 0.000…1800.000 s 0.005 s 0.300 s Forward start detection reset time. Starts to count from first detected forward (faulty feeder) spike.
Page 92: Current Unbalance I2> (46/46R)
Application Guide - NP900 Series 92 (504 In the register of the IEF function is recorded start, trip or blocked “On” event process data. In the table below is presented the structure of HOC function register content. This information is available in 12 last recorded events for all provided instances separately.
Page 93 Application Guide - NP900 Series 93 (504 The function can be operating on instant or time delayed mode. In time delayed mode the operation can be selected for definite time or IDMT. For IDMT operation IEC and ANSI standard time delays are supported as well as custom parameters.
Page 94 Application Guide - NP900 Series 94 (504 processing. -20ms averaged value of the selected magnitude is used for pre-fault data registering. Table 3.2.7.1-68 Analogic magnitudes used by the CUB function. Signal Description Time base Positive sequence current magnitude 5 ms...
Page 95 Application Guide - NP900 Series 95 (504 If the blocking signal is not activated when the pick-up element activates, a START signal is generated and the function proceeds to the time characteristics calculation. If blocking signal is active when pick-up element activates a BLOCKED signal will be generated and the function shall not process the situation further.
Page 96 Application Guide - NP900 Series 96 (504 Uniquely to current unbalance protection there is also “Curve1” delay available which follows the formula below: � � 2meas t = Operating time = Calculated negative sequence 2meas = Nominal current = Constant K value (user settable delay multiplier) = Pick-up setting of the function.
Page 97 Application Guide - NP900 Series 97 (504 Table 3.2.7.4-70 Operating time characteristics setting parameters. Name Range Step Default Description Delay Type Selection of the delay type time counter. IDMT Selection possibilities are dependent (IDMT, Inverse Definite Minimum Time) and independent (DT, Definite Time) characteristics.
Page 98 Application Guide - NP900 Series 98 (504 Table 3.2.7.4-71 Reset time characteristics setting parameters. Release Time 0.000…150.000 s 0.005 s 0.06 s Resetting time. Time allowed in between delay of pick-ups if the pick-up has not lead into trip operation. During this time the start signal is held on for the timers if delayed pick-up release is active.
Page 99 Application Guide - NP900 Series 99 (504 Table 3.2.7.5-72. Event codes of the CUB-function instances 1 – 4. Event Event Event Event Number channel Event block name Code Description Type 2048 32 CUB1 0 Start ON 2049 32 CUB1 1 Start OFF...
Page 100: Harmonic Over Current I )
Application Guide - NP900 Series 100 (504 3.2.8 H > (50 ARMONIC OVER CURRENT Harmonic overcurrent function (HOC) is used for non-directional instant- and time delayed harmonic overcurrent detection and clearing for various applications including feeder, filter and machine applications of utilities and industry. The number of available instances of the function depends of the IED model.
Page 101 Application Guide - NP900 Series 101 (504 Figure 3.2.8-47 Simplified function block diagram of the HOC function. 3.2.8.1 M EASURED INPUT VALUES Function block uses analog current measurement values from the phase currents or residual currents. For each measurement input the HOC function block utilizes the...
Page 102 Application Guide - NP900 Series 102 (504 Table 3.2.8.1-74 Analogic magnitudes used by the HOC function. Signal Description Time base IL1FFT Magnitudes (rms) of phase L1/A current components: 5 ms Fundamental, 2 harmonic, 3 harmonic, 4 harmonic, 5 harmonic 7...
Page 103 Application Guide - NP900 Series 103 (504 3.2.8.2 O PERATING MODE AND INPUT SELECTION The function can be set to monitor the ratio of the measured harmonic to the measured fundamental component or directly the per unit value of the harmonic current. Also the user needs to select the correct measurement input.
Page 104 Application Guide - NP900 Series 104 (504 Table 3.2.8.3-76 Pick-up characteristics setting Name Range Step Default Description Ihset pu 0.10 … 40.00 x In 0.01 x In 1.20 x In Pick-up setting (per unit monitoring) Ih/IL 1…4000 % 20 %...
Page 105 Application Guide - NP900 Series 105 (504 HOC function offers four independent instances which events are segregated for each instance operation. In the function is available 12 last registers where the triggering event of the function (start, trip or blocked) is recorded with time stamp and process data values.
Page 106: Circuit Breaker Failure Protection (Cbfp) (50Bf)
Application Guide - NP900 Series 106 (504 phases measurement values are recorded event the harmonic is measured only in one phase. 3.2.9 C (CBFP) (50BF) IRCUIT BREAKER FAILURE PROTECTION Circuit breaker failure protection (CBFP) function is used for monitoring the circuit breaker operation after it has been tripped.
Page 107 Application Guide - NP900 Series 107 (504 Figure 3.2.9-48 Simplified function block diagram of the CBFP function. 3.2.9.1 M EASURED INPUT VALUES Function block uses analog current measurement values. Function uses always the fundamental frequency magnitude of the current measurement input. For residual current measurement I01, I02 or calculated I0 can be selected.
Page 108 Application Guide - NP900 Series 108 (504 Table 3.2.9.1-80 Operating mode and input signals selection Name Range Step Default Description I0Input Not in use Not in Selection of the residual current monitoring from the two separate residual measurements I01 and I02 or...
Page 109 Application Guide - NP900 Series 109 (504 3.2.9.3 F UNCTION BLOCKING In the blocking element the block signal is checked in the beginning of each program cycle. Blocking signal is received from the blocking matrix for the function dedicated input.
Page 110 Application Guide - NP900 Series 110 (504 In following figures are presented few typical cases of CBFP situations. Figure 3.2.9.4-49 Into the IED is configured Trip, Retrip and CBFP. In application where the circuit breaker has retrip / redundant trip coil available, retrip functionality can be used.
Page 111 Application Guide - NP900 Series 111 (504 Figure 3.2.9.4-50 Retrip and CBFP when selected criteria is current only. In case when the current based protection activates so that either Iset and/or I0Sset current threshold setting is exceeded the counters for retrip and CBFP start to calculate the set operating time.
Page 112 Application Guide - NP900 Series 112 (504 the monitored output contact is controlled (primary protection operates). From the tripping signal of the primary protection stage the counters for retrip and CBFP start to calculate the set operating time. The tripping of the primary protection stage is constantly monitored...
Page 113 Application Guide - NP900 Series 113 (504 current based functions with added security from the current monitoring of the CBFP function and other function trips can be also included to the CBFP functionality. Figure 3.2.9.4-53 Into the IED is configured Trip and CBFP.
Page 114 Application Guide - NP900 Series 114 (504 Figure 3.2.9.4-54 CBFP when selected criteria is current only. In case when the current based protection activates so that either Iset and/or I0Sset current threshold setting is exceeded, the counter for CBFP start to calculate the set operating time.
Page 115 Application Guide - NP900 Series 115 (504 In case when the current based protection activates so that either Iset and/or I0Sset current threshold setting are exceeded the counter for CBFP is halted until the monitored output contact is controlled (primary protection operates). From the tripping signal of the primary protection stage the counter for CBFP start to calculate the set operating time.
Page 116 Application Guide - NP900 Series 116 (504 Figure 3.2.9.4-57 IED is configured as dedicated CBFP unit. In some applications dedicated circuit breaker protection unit is required. When the CBFP function is configured to operate with DI signal it can be used in these applications. When the IED is used for this purpose the tripping signal is wired to the IED digital input and the IED:s own trip signal is used for CBFP purpose only.
Page 117 Application Guide - NP900 Series 117 (504 Figure 3.2.9.4-58 Dedicated CBFP operation from binary input signal. In this mode the CBFP operates from binary input signal only. Additionally also current and output relay monitoring can be used. The counter for the CBFP is started when the digital input is activated.
Page 118: Restricted Earth Fault / Cable End Differential (Ref) I0 > (87N)
Application Guide - NP900 Series 118 (504 Table 3.2.9.5-83. Event codes of the CBFP function instance Event Event Event Event Number channel Event block name Code Description Type 2817 44 CBF1 1 Start ON 2818 44 CBF1 2 Start OFF...
Page 119 Application Guide - NP900 Series 119 (504 Outputs of the function are REF Trip and Blocked signals. Setting parameters are static inputs for the function which are changed only by user input in the setup phase of the function. REF function utilizes total of eight separate setting groups which can be selected from one common source.
Page 120 Application Guide - NP900 Series 120 (504 3.2.10.1 M EASURED INPUT VALUES Function block uses analog current measurement values. Function uses the fundamental frequency magnitude of the current measurement inputs and calculated residual current with residual current measurement. For residual current measurement I01 or I02 can be selected.
Page 121 Application Guide - NP900 Series 121 (504 Table 3.2.10.2-87 Pick-up characteristics setting (SG selectable) Name Range Step Default Description I0 Input 0: I01 Selection of the used residual current 1: I02 measurement input. Default setting is 0: I01 I0 Direction 0:Add Differential current calculation mode.
Page 122 Application Guide - NP900 Series 122 (504 Equations for the differential characteristics are as below: Differential current (calculation is based into user selected inputs and direction): = �IL1 + IL2 + IL3� + I01 Diff+I01 = �IL1 + IL2 + IL3�-I01 Diff-I01 = �IL1 + IL2 + IL3�...
Page 123 Application Guide - NP900 Series 123 (504 User settable variables are binary signals from the system. Blocking signal needs to reach the IED minimum of 5 ms before the set operating delay has passed for blocking to be active in time.
Page 124 Application Guide - NP900 Series 124 (504 If in the cable end should occur any starting faults the cable end differential catches the difference in between of the ingoing and outgoing residual currents and the resulting signal can be used for alarming or tripping purpose for the feeder with failing cable end.
Page 125 Application Guide - NP900 Series 125 (504 Characteristics Differential characteristics DIFF 2.00 1.00 0.00 I Bias Figure 3.2.10.3-64 Restricted earth fault on inside of Y winding transformer. 3.2.10.4 E VENTS AND REGISTERS The REF function generates events and registers from the status changes of the Trip activated and blocked signals.
Page 126: Thermal Overload Protection For Feeders T > (49F)
Application Guide - NP900 Series 126 (504 3.2.11 T > (49F) HERMAL OVERLOAD PROTECTION FOR FEEDERS Thermal overload function for feeder (TOLF) is used for cables and overhead lines thermal capacity monitoring and protection. Also this function can be used for any single time constant application like inductor chokes, certain types of transformers and any other static units which don’t have active cooling in addition to the cables and overhead lines.
Page 127 Application Guide - NP900 Series 127 (504 its heating constant tau (τ), 63% of the nominal thermal capacity is used. When the loading continues until five times this given constant the used thermal capacity indefinitely approaches to 100% but never exceeds it. With a single time constant model cooling of the object follows this same behavior reversible to the heating when the current feeding is completely zero.
Page 128 Application Guide - NP900 Series 128 (504 temperature. The calculated coefficient is linear correction factor which is presented with following formulas: Amb<t = � × ( t ) � + k Amb<t × ( t ) � + 1.0 = �...
Page 129 Application Guide - NP900 Series 129 (504 This mentioned ambient temperature coefficient relates to nominal temperature reference. By default is used +15 ̊ C (ground dug cables) which gives coefficient value of 1.00 for the thermal replica. Settable thermal capacity curve uses linear interpolation for ambient temperature correction with maximum 10 pairs of temperature –...
Page 130 Application Guide - NP900 Series 130 (504 The correction coefficient curve for ambient temperature is shown in the figure. The reference temperature for ground dug cables usually is 15 ̊ C which gives correction coefficient of 1.00 which referred nominal temperature in this case.
Page 131 Application Guide - NP900 Series 131 (504 Figure 3.2.11-70 Initial data of the cable temperature characteristics and current ratings with different installations and copper or aluminium conductors. Based into the given data can be seen the currents which in given installation and construction methods will achieve the given temperature in given standard conditions.
Page 132 Application Guide - NP900 Series 132 (504 Figure 3.2.11-71 General presumptions of the high voltage cables. If the installation conditions vary from the presumption conditions, manufacturers may give additional information of how the current carrying capacity should be corrected in order to match changed conditions.
Page 133 Application Guide - NP900 Series 133 (504 Figure 3.2.11-72 Correction coefficients for the current carrying capacity given by the manufacturer. As an example of the k (service factor, current carrying capacity) factor importance let’s calculate cable installation with correct k factor and without setting it to correct value.
Page 134 Application Guide - NP900 Series 134 (504 Initial data for the set-up of the thermal image: 500 mm cross sectional 66 kV copper cable is installed into ground. Its 1s permissible short circuit current is 71.4 kA and its insulation is XLPE. The cables screen circuit is open and the laying of the cable is flat.
Page 135 Application Guide - NP900 Series 135 (504 With maximum allowed load temperature 89 ̊ C has been reached with thermal capacity 99.6% used. From this result can be noted that the thermal image matches perfectly into expectations. Cable alarm from the...
Page 136 Application Guide - NP900 Series 136 (504 Now when trying to load the cable with the given nominal current can be seen that the actual cable current carrying capacity is much lower than in presumption conditions. Normal loading current can now get the cable too warm and endanger its withstandability.
Page 137 Application Guide - NP900 Series 137 (504 3.2.11.1 T HERMAL OVERLOAD FUNCTION Blocking signal and setting group selection controls the operating characteristics of the function during normal operation. Outputs of the function are TOLF Trip and Blocked signals. Setting parameters are static inputs for the function which are changed only by user input in the setup phase of the function.
Page 138 Application Guide - NP900 Series 138 (504 3.2.11.2 M EASURED INPUT VALUE Function block uses analog current measurement values. Function uses the fundamental frequency magnitude of the current measurement inputs and calculated residual current with residual current measurement. For residual current measurement I01 or I02 can be selected.
Page 139 Application Guide - NP900 Series 139 (504 Table 3.2.11.2-92 Thermal replica settings. Name Range Step Default Description IN thermal cap current 0.10…40.00 xIn 0.01 xIn 1.00 xIn Current for the 100 % thermal capacity to be used (pick-up current in p.u., with this current t will be achieved in time τ...
Page 140 Application Guide - NP900 Series 140 (504 Table 3.2.11.2-93 Environmental settings Name Range Step Default Description Object max temp (tmax = 0…500 deg 1 deg Maximum allowed temperature for 100%) the protected object. Default setting is +90 degrees and it suits for Celsius...
Page 141 Application Guide - NP900 Series 141 (504 Ambient lin. or curve is set to “Set curve”. Amb.Temp.k1...k10 0.01…5.00 1.00 0.01 Coefficient value for the temperature reference point. Coefficient and temperature reference points must be set as pairs. Setting is visible if Ambient lin.
Page 142 Application Guide - NP900 Series 142 (504 3.2.11.4 F UNCTION BLOCKING In the blocking element the block signal is checked in the beginning of each program cycle. Blocking signal is received from the blocking matrix for the function dedicated input.
Page 143 Application Guide - NP900 Series 143 (504 Table 3.2.11.5-96 Measurements Name Range Description / values Currents 0: Primary A Active phase current measurement from IL1(A), IL2(B) and 1: Secondary A IL3(C) phases in given scalings. 2: Per unit Thermal Image 0:Thermal image calc.
Page 144: Arc Fault Arci> (50Arc/50Narc)
Application Guide - NP900 Series 144 (504 Table 3.2.11.6-98. Event codes of the TOLF function instance Event Event Event Number channel Event block name Code Description 4288 67 TOLF1 0 Alarm1 On 4289 67 TOLF1 1 Alarm1 Off 4290 67 TOLF1...
Page 145 Application Guide - NP900 Series 145 (504 conditions are met. This feature can be enabled or disabled in the protection functions settings menu. Activation and deactivation of this stage can be done inside the protection functions menus info-tab. Outputs of the function are Trip and Blocked signals. Setting parameters are static inputs for the function which are changed only by user input in the setup phase of the function.
Page 146 The following example gives a better understanding of setting up the arc protection function. In the following cases NP900 models are used to extend the protection of Zone2 and to protect each outgoing feeder (Zone3). Figure 3.2.12.1-78 Scheme IA1 single-line diagram with NP900 series relays. A996A...
Page 147 Application Guide - NP900 Series 147 (504 To set the zones for the NP900 models sensor channels start by enabling the protected zones which in this case are Zones 1 and 2. Then define which sensor channels are sensing which zones. In this case sensor channels S1 and S2 are protecting Zone 1.
Page 148 Application Guide - NP900 Series 148 (504 Table 3.2.12.3-101 Enabled Zone pick-up characteristics setting Name Description Phase current pick-up Phase current measurement pick-up value in per- unit value. I0 input selection Selection of the residual current channel between I01 and I02 Res.current pick-up...
Page 149 Application Guide - NP900 Series 149 (504 User settable variables are binary signals from the system. Blocking signal needs to reach the IED minimum of 5 ms before the set operating delay has passed for blocking to be active in time.
Page 150 Application Guide - NP900 Series 150 (504 Table 3.2.12.5-102. Event codes of the ARC function. Event Event Event Event Alarm Number channel Event block name Code Description Type Type 4736 74 ARC1 0 Zone1 Trip On 4737 74 ARC1 1 Zone1 Trip Off...
Page 151: Over Voltage U> (59)
Application Guide - NP900 Series 151 (504 3.2.13 O U> (59) VER VOLTAGE Overvoltage function (OV) is used for instant- and time delayed overvoltage protection for various applications including feeder, filter and machine applications of utilities and industry. Each IED with voltage protection module has four available instances of the function (U>, U>>, U>>>, U>>>>).
Page 152 Application Guide - NP900 Series 152 (504 Figure 3.2.13-79 Simplified function block diagram of the OV function. 3.2.13.1 M EASURED INPUT VALUES For the function block is used analog voltage measurement values. Function block utilizes always peak-to-peak measurement from samples and the monitored magnitude is fundamental frequency RMS values.
Page 153 Application Guide - NP900 Series 153 (504 3.2.13.2 P UP CHARACTERISTICS Uset Pick-up of the OV function is controlled by setting parameter, which defines the maximum allowed measured voltage before action from the function. The function constantly calculates the ratio in between of the Uset and measured magnitude (Um) per all three voltages.
Page 154 Application Guide - NP900 Series 154 (504 If blocking signal is active when pick-up element activates a BLOCKED signal will be generated and the function shall not process the situation further. If START function has been activated before blocking signal it will reset and the release time characteristics are processed as in case of when pick-up signal is reset.
Page 155: Under Voltage U< (27)
Application Guide - NP900 Series 155 (504 Table 3.2.13.6-107. Event codes of the OV function instance 1 – 4. Event Event Event Event Number channel Event block name Code Description Type 5440 85 OV1 0 Start ON 5441 85 OV1...
Page 156 Application Guide - NP900 Series 156 (504 frequency component or line- to neutral fundamental frequency component if so chosen. If protection is based to line- to line voltage, during earth fault in isolated or compensated networks the undervoltage protection is not affected. Undervoltage protection stage has two blocking instances, internal blocking based on voltage measurement and low voltage or external blocking during for example VT fuse failure.
Page 157 Application Guide - NP900 Series 157 (504 Figure 3.2.14-80 Simplified function block diagram of the UV function. 3.2.14.1 M EASURED INPUT VALUES Analog voltage measurement values are used for the function block. Function block utilizes always peak-to-peak measurement from samples and the monitored magnitude is fundamental frequency RMS values.
Page 158 Application Guide - NP900 Series 158 (504 dual- or each voltage Um decrease below the Uset value will cause pick-up operation of the function. Table 3.2.14.2-110 Pick-up characteristics setting Name Description Range Step Default Uset Pick-up 20.00 … 120.00 % 0.01 % Un...
Page 159 Application Guide - NP900 Series 159 (504 3.2.14.3 U SING LOCK SETTING TO PREVENT NUISANCE TRIPS To prevent the relay from tripping in a situation where the network is de-energized it is Block setting advised to use the parameter. When the measured voltage drops below the set value relay will not give a tripping signal.
Page 160 Application Guide - NP900 Series 160 (504 3.2.14.5 F UNCTION BLOCKING In the blocking element the block signal is checked in the beginning of each program cycle. Blocking signal is received from the blocking matrix for the function dedicated input.
Page 161 Application Guide - NP900 Series 161 (504 3.2.14.7 E VENTS AND REGISTERS The UV function generates events and registers from the status changes of start, trip and blocked. To main event buffer is possible to select status “On” or “Off” messages. The UV function offers four independent instances which events are segregated for each instance operation.
Page 162: Vector Jump (78)
Application Guide - NP900 Series 162 (504 3.2.15 V (78) ECTOR JUMP Distribution systems may include different kind of distributed power generation sources such as wind farms and diesel/fuel generators. When a fault occurs in the distribution system, it is usually detected and isolated by the protection system closest to the faulty point, resulting in the shutdown of a part or whole electrical power system.
Page 163 Application Guide - NP900 Series 163 (504 Inputs for the function are the available stages, setting parameters and measured and pre-processed voltage magnitudes and binary input signals. Function outputs ALARM, TRIP and BLOCKED signals can be used for direct IO controlling and also for user logic programming.
Page 164 Application Guide - NP900 Series 164 (504 Table 3.2.15.1-113 Analogic magnitudes used by the VJP function. Signal Description Time base Measured Line-to-Line voltage U 5 ms Measured Line-to-Line voltage U 5 ms Measured Line-to-Line voltage U 5 ms Measured Line-to-Neutral voltage U...
Page 165 Application Guide - NP900 Series 165 (504 in phase L1 in the network. The voltage level is not reduced to zero or either the voltage in any phase is totally lost. Phases without fault condition normally remain with the same value.
Page 166 Application Guide - NP900 Series 166 (504 3.2.15.3 U SING LOCK SETTING TO PREVENT NUISANCE TRIPS To prevent the relay from tripping in a situation where the network is de-energized it is Block setting advised to use the parameter. When the measured voltage drops below the set value relay will not give an alarm or trip signal.
Page 167: Positive Sequence Over- And Under Voltage U1>/< (59P/27P/47)
Application Guide - NP900 Series 167 (504 User settable variables are binary signals from the system. Blocking signal needs to reach the IED minimum of 5 ms before the set operating delay has passed for blocking to be active in time.
Page 168 Application Guide - NP900 Series 168 (504 voltage level. Protection stages can be set to protect against under- or overvoltage. Blocking signal and setting group selection controls the operating characteristics of the function during normal operation. 3.2.16.1 P OSITIVE SEQUENCE VOLTAGE CALCULATION Below is presented the formula for symmetric component calculation and therefore to VUB positive sequence calculation.
Page 169 Application Guide - NP900 Series 169 (504 See positive sequence calculation examples below. Swapped Swapped Vector 120 degrees 240 degrees divided by three Normal situation. Vector Swapped Swapped 120 degrees 240 degrees divided by three Earth fault in isolated network.
Page 170 Application Guide - NP900 Series 170 (504 3.2.16.2 N EGATIVE SEQUENCE CALCULATION Below is presented the formula for symmetric component calculation and therefore to NSV calculation. U2 = 1 3 � (U + aU a = 1∠120° = 1∠240° = Line to neutral voltages L1…3...
Page 171 Application Guide - NP900 Series 171 (504 Outputs of the function are Start Trip and Blocked signals. Blocking can be executed by using external block signal or by using low voltage block function integrated to the stage. Setting parameters are static inputs for the function which are changed only by user input in the setup phase of the function.
Page 172 Application Guide - NP900 Series 172 (504 In the following figure is presented the simplified function block diagram of the positive sequence protection. Figure 3.2.16.2-88 Simplified function block diagram of the sequence voltage function. 3.2.16.3 M EASURED INPUT VALUES The function block uses analog voltage measurement values. Function block utilizes always fundamental frequency RMS values.
Page 173 Application Guide - NP900 Series 173 (504 Name Description Range Default Measured Decision which U1 Pos seq.Volt magnitude calculated U2 Neg seq.Volt seq.Volt voltage supervised Reset ratio of 97 % in over voltage applications is inbuilt in the function and is always...
Page 174 Application Guide - NP900 Series 174 (504 3.2.16.5 U SING LOCK SETTING TO PREVENT NUISANCE TRIPS In case “Under <” is the chosen tripping condition to prevent the relay from tripping in a Under block setting situation where the network is de-energized it is advised to use the Ublk parameter.
Page 175 Application Guide - NP900 Series 175 (504 3.2.16.7 F UNCTION BLOCKING In the blocking element the block signal is checked in the beginning of each program cycle. Blocking signal is received from the blocking matrix for the function dedicated input.
Page 176: Neutral Voltage U0> (59N)
Application Guide - NP900 Series 176 (504 Table 3.2.16.9-119. Event codes of the VUB function instance 1 – 4. In the register of the VUB function is recorded start, trip or blocked “On” event process data. In the table below is presented the structure of VUB function register content. This information is available in 12 last recorded events for all provided instances separately.
Page 177 Application Guide - NP900 Series 177 (504 ⁄ 100 √ 3 secondary the earth fault is 100% of Un when calculated zero sequence voltage reaches V= 57.74 V. Below is presented the formula for symmetric component calculation and therefore to zero sequence voltage calculation.
Page 178 Application Guide - NP900 Series 178 (504 NOV function is capable to use measured neutral voltage as well. In case line to line voltage of system is 100 V secondary the earth fault is 100% of Un when measured neutral voltage is 100 V. See picture below.
Page 179 Application Guide - NP900 Series 179 (504 Time stamp resolution is 1ms. Function provides also cumulative counters for START, TRIP and BLOCKED events. In the following figure is presented the simplified function block diagram of the NOV function. Figure 3.2.17-92 Simplified function block diagram of the NOV function.
Page 180 Application Guide - NP900 Series 180 (504 3.2.17.2 R TIME INFO DISPLAYED OF THE FUNCTION The relays Info-page displays useful information in real time of the state of the protection function either through relays HMI display or with SMART9 software when connection there is a connection to relay and Live Edit-mode is activated.
Page 181 Application Guide - NP900 Series 181 (504 If blocking signal is active when pick-up element activates a BLOCKED signal will be generated and the function shall not process the situation further. If START function has been activated before blocking signal it will reset and the release time characteristics are processed as in case of when pick-up signal is reset.
Page 182: Over Power (32)
(32) VER POWER NP900 series IEDs with both voltage –and current cards can have over power function (POW), which is used for instant- and time delayed active over power protection. In applications like feeder-, generator- and motor protection it is used to detect overload situations by measuring three phase active power.
Page 183 Application Guide - NP900 Series 183 (504 Below is presented formula for three phase active power (P) calculation when line to neutral voltages are available: × I cos φ Where, × I cos φ UL1…UL3 = Line to neutral voltage ×...
Page 184 Application Guide - NP900 Series 184 (504 Figure 3.2.18-93 Simplified function block diagram of the OPW function. 3.2.18.1 M EASURED INPUT VALUES Three phase active power value is used for the function block. For pre-fault data registering is used -20ms averaged value.
Page 185 Application Guide - NP900 Series 185 (504 3.2.18.3 F UNCTION BLOCKING In the blocking element the block signal is checked at the beginning of each program cycle. Blocking signal is received from the blocking matrix for the function dedicated input.
Page 186: Under Power (37)
(37) NDER POWER NP900 series IEDs with both voltage –and current cards can have under power function (UPW), which is used for instant- and time delayed active under power protection. Under power function detects loss-of-load conditions when there is no significant loss of current.
Page 187 Application Guide - NP900 Series 187 (504 Outputs of the function are Start Trip and Blocked signals. Setting parameters are static inputs for the function which are changed only by user input in the setup phase of the function. Under power function utilizes total of eight separate setting groups which can be selected from one common source.
Page 188 Application Guide - NP900 Series 188 (504 Table 3.2.19.1-129 Measurement magnitudes used by the UPW function. Signal Description Time base Total 3 phase active power 3PH Active power (P) 5 ms 3.2.19.2 P UP CHARACTERISTICS Pset< Pick-up of the UPW function is controlled by setting parameter, which defines the maximum allowed measured three phase active power before action from the function.
Page 189 Application Guide - NP900 Series 189 (504 Table 3.2.19.2-130 Pick-up characteristics setting Name Description Range Step Default Pset< Pick-up setting 0.0 … 100000 kW 0.01 kW 100 kW Pset< Low power block 0.0 … 100000 kW 0.01 kW 50 kW The pick-up activation of the function is not directly equal to start-signal generation of the function.
Page 190: Reverse Power (32R)
(32R) EVERSE POWER NP900 series IEDs with both voltage –and current cards can have reverse power function (RPW), which is used for instant- and time delayed active reverse power protection. In generator protection applications reverse power protection function is used to prevent damage in situations where synchronous generator is running like a motor when the generator draws active power.
Page 191 Application Guide - NP900 Series 191 (504 Below is presented formula for three phase active power (P) calculation when line to neutral voltages are available: × I cos φ Where, × I cos φ UL1…UL3 = Line to neutral voltage ×...
Page 192 Application Guide - NP900 Series 192 (504 Figure 3.2.20-96 Simplified function block diagram of the RPW function. 3.2.20.1 M EASURED INPUT VALUES Three phase active power value is used for the function block. For pre-fault data registering is used -20ms averaged value.
Page 193 Application Guide - NP900 Series 193 (504 3.2.20.3 F UNCTION BLOCKING In the blocking element the block signal is checked at the beginning of each program cycle. Blocking signal is received from the blocking matrix for the function dedicated input.
Page 194: Over- And Under Frequency F>/< (81O/81U)
Application Guide - NP900 Series 194 (504 Table 3.2.20.5-135. Event codes of the RPW function. Event Event Event Event Alarm Number channel Event block name Code Description Type Type 4736 74 RPW1 0 Start ON 4737 74 RPW1 1 Start OFF...
Page 195 Application Guide - NP900 Series 195 (504 Activation and deactivation of each individual stage can be done inside the protection function menus info-tab. Outputs of the function are Start Trip and Blocked signals. Setting parameters are static inputs for the function which are changed only by user input in the setup phase of the function.
Page 196 Application Guide - NP900 Series 196 (504 Figure 3.2.22-97 Simplified function block diagram of the FRQV function. 3.2.21.1 M EASURED INPUT VALUES Frequency protection function compares measured frequency to pick-up setting given in Hz. Source of measured frequency depends on the factory defined tracking reference which can be checked from frequency tab behind measurements-menu.
Page 197 Application Guide - NP900 Series 197 (504 pick-up setting and measured frequency. Reset ratio of 97 % is inbuilt in the function and is always related to the pick-up value. Table 3.2.22.2-138 Pick-up characteristics setting Name Description Range Step Default fset>...
Page 198 Application Guide - NP900 Series 198 (504 3.2.21.4 F UNCTION BLOCKING In the blocking element the block signal is checked at the beginning of each program cycle. Blocking signal is received from the blocking matrix for the function dedicated input.
Page 199 Application Guide - NP900 Series 199 (504 Table 3.2.22.5-139. Event codes of the FRQV function. Event Event Event Event Alarm Number channel Event block name Code Description Type Type 6336 99 FRQV1 0 f> Start ON 6337 99 FRQV1 1 f> Start OFF...
Page 200: Rate Of Change Of Frequency (Rocof) (81R)
Application Guide - NP900 Series 200 (504 Table 3.2.22.5-140. Register content. Date & Time Event f Pretrig (Hz) f Fault (Hz) Setting group in code dd.mm.yyyy 6336- Start –20ms Fault frequency Starts used at the hh:mm:ss.mss 6383 averages triggering moment Descr.
Page 201 Application Guide - NP900 Series 201 (504 In the figure above is presented an example case of df/dt function operation when the frequency is decreasing. If the f is activated df/dt doesn’t trip no matter how fast the limit measured frequency changes if it’s over the f or under f .
Page 202 Application Guide - NP900 Series 202 (504 Figure 3.2.23-98 Simplified function block diagram of the ROCOF function. 3.2.22.1 M EASURED INPUT VALUES Rate of change of frequency protection function compares measured df/dt to pick-up setting given in Hz/s. Source of measured frequency depends on the factory defined tracking reference which can be checked from frequency tab behind measurements- menu.
Page 203 Application Guide - NP900 Series 203 (504 Table 3.2.23.2-142 Pick-up characteristics setting Name Description Range Step Default df/dt>/<(1…8)pick-up Pick-up setting 0.01 … 10.00 0.01Hz/s 0.2 Hz/s df/dt>/<(1…8) f< limit f< limit 7.00…65.00 0.01Hz/s 49.95 Hz/s df/dt>/<(1…8) f> limit f> limit 10.00…70.00...
Page 204 Application Guide - NP900 Series 204 (504 3.2.22.5 E VENTS The ROCOF function generates events and registers from the status changes of start, trip and blocked. To main event buffer it’s possible to select status “On” or “Off” messages. In the function is available 12 last registers where the triggering event of the function (start, trip or blocked) is recorded with time stamp and process data values.
Page 205: Programmable Stage (99)
Application Guide - NP900 Series 205 (504 Table 3.2.23.5-144. Register content. Date & Time Event df/dt Pretrig f Pretrig (Hz) df/dt Fault f Fault (Hz) Setting group in code (Hz/s) (Hz/s) dd.mm.yyyy 6592- Start –20ms Start –20ms Fault df/dt Fault frequency hh:mm:ss.mss...
Page 206 Application Guide - NP900 Series 206 (504 It should be noted that setting the available stages will not set those stages active but the available stages also need to be enabled individually with PSx>/< Enable parameter. The active stages shows its current state, expected operating time and also the time remaining to trip under the activation parameter.
Page 207 Application Guide - NP900 Series 207 (504 Mode Description 0=Mag1 x Mag2 Signal1 x Signal2 multiply. The comparison uses the product of Signal1 x Signal2 calculation 1=Mag1 / Mag2 Signal1 / Signal2 division. The comparison uses the product of Signal1 / Signal2 2=Max(Mag1,Mag2) Bigger value of the chosen signals is used in the comparison.
Page 208 Application Guide - NP900 Series 208 (504 The settings for different comparison setting are in setting groups which means by changing the setting group each signal parameter can be changed by a signal. When setting the comparators you first choose the comparator mode. The following...
Page 209 Application Guide - NP900 Series 209 (504 Pick-up level is set for each comparison individually. When setting up pick-up level the used modes and the desired action need to be taken into consideration. The pick-up limit can be set as either positive or negative.
Page 210 Application Guide - NP900 Series 210 (504 47= I01 17th h. I01 17th harmonic in per unit value 48= I01 19th h. I01 19th harmonic in per unit value IL02 Description 49=I02ff(p.u.) I02 Fundamental frequency in per unit value 50= I02 2.h I02 2nd harmonic in per unit value 51= I02 3.h...
Page 211 Application Guide - NP900 Series 211 (504 Voltages category Description Phase-Phase voltages 1=UL12Mag UL12 Primary voltage V 2=UL23Mag UL23 Primary voltage V 3=UL31Mag UL31 Primary voltage V Phase-Neutral voltages 4=UL1Mag UL1 Primary voltage V 5=UL2Mag UL2 Primary voltage V 6=UL3Mag...
Page 212 Application Guide - NP900 Series 212 (504 16=Z12Sec Impedance Z L12 secondary ohm 17=Z23Sec Impedance Z L23 secondary ohm 18=Z31Sec Impedance Z L31 secondary ohm 19=Z12Angle Impedance Z L12 angle 20=Z23Angle Impedance Z L23 angle 21=Z31Angle Impedance Z L31 angle...
Page 213 Application Guide - NP900 Series 213 (504 function. Programmable stage utilize total of eight separate setting groups which can be selected from one common source. The function can be operating on instant or time delayed mode. In time delayed mode the operation can be selected for definite time.
Page 214 Application Guide - NP900 Series 214 (504 When using the release delay option where the operating time counter is calculating the operating time during the release time, function will not trip if the input signal is not activated again during the release time counting.
Page 215 Application Guide - NP900 Series 215 (504 Table 3.2.21.5-146. Event codes of the PGS function instance 1 – 10. In the register of the PGS function is recorded start, trip or blocked “On” event process data. In the table below is presented the structure of OV function register content. This information is available in 12 last recorded events for all provided instances separately.
Page 216 Application Guide - NP900 Series 216 (504 Table 3.2.21.5-147. Register content. Date & Time Event >/< Mag# Mag#/Set# Trip time Used code remaining dd.mm.yyyy 8576- Magnitude Measured 0 ms - 1 - 8 hh:mm:ss.mss 8637 # value magnitude/Pick- 1800 s Descr.
Page 217: Motor Protection Module
Application Guide - NP900 Series 217 (504 3.3 M OTOR PROTECTION MODULE 3.3.1 M (MST) OTOR STATUS MONITORING Motor status monitoring function (MST) is designed to be the common place to set up all necessary motor data and to select the used motor protection functions. Settings related to the protection functions can be edited also inside of each function and after changed they will be also updated into MST function.
Page 218 Application Guide - NP900 Series 218 (504 Figure 3.3.1-100 MST function outputs activation. “Motor stopped” signal is activated when the current is under “No load current” limit for more than 10 ms time. When current increases from this status to over “Start detect current”...
Page 219 Application Guide - NP900 Series 219 (504 Application example of motor starting scheme and usage of motor status signals of MST function. When motor is starting usually the low set stage overcurrent is either blocked or in some relays the setting value is multiplied by some given factor in order that the protection stage does not activate and prevent the motor from starting especially in cases when the low set overcurrent stage operating time is shorter than the start-up time of the protected motor.
Page 220 Application Guide - NP900 Series 220 (504 Problem in this example application may be that if during the start-up of the motor, short circuit fault occurs in cases when the overcurrent stage is blocked it may prolong the fault clearing time since the relay is considering this situation still as starting. For this purpose following logic can be used to prevent the prolongation of the fault clearing time during startup of the motor.
Page 221 Application Guide - NP900 Series 221 (504 operate on its set timer settings. Requirement for this scheme to work properly is that the motor start detection current is set below of to be blocked overcurrent stage. 3.3.1.1 S ETTINGS AND SIGNALS Settings of the motor status monitor (MST) function are mostly shared with motor protection functions in the motor module of the IED.
Page 222 Application Guide - NP900 Series 222 (504 Max locked rotor 0.1…40.0xIn 0.1xIn 7.5 xIn Maximum locked rotor current of the current TM> (49M) motor. This setting defines the Ist> (48) current limit which is maximum Im> (50M) current for the motor to draw in locked rotor situation (starting or stalled).
Page 223 Application Guide - NP900 Series 223 (504 TM> is activated and in use. Safe stall time 0.1…600.0s 0.1s 20.0s Safe stall time when motor is cold. If cold TM> (49M) this value is not informed then set to Ist> (48) same than hot stall time.
Page 224 Application Guide - NP900 Series 224 (504 Table 3.3.1.1-149. Output signals of the MST function Name Range Step Default Description Motor stopped 0=Not active Signal is active when the MST function 1=Active detects current below “No load current”. This signal presents situation when the motor is not running.
Page 225 Application Guide - NP900 Series 225 (504 3.3.1.2 E VENTS MST function generates events from detected motor status. From changes of the events also data register is available. Table 3.3.1.2-150. Event codes of the MST function. Event Event Event Event...
Page 226: Thermal Overload Protection For Machines T
Application Guide - NP900 Series 226 (504 3.3.2 T > (49M) HERMAL OVERLOAD PROTECTION FOR MACHINES Thermal overload function for machines (TOLM) is used for electric machines like synchronous and asynchronous motors and generators thermal capacity monitoring and protection. This function can also be used for any single or multiple time constant applications like inductor chokes, certain types of transformers and any other static units which don’t have active cooling in addition to the cables and overhead lines.
Page 227 Application Guide - NP900 Series 227 (504 = Current for the 100 % thermal capacity to be used (pick-up current in p.u., with this current t will be achieved in time τ) = Loading factor (service factor) coefficient, maximum allowed load current in per unit...
Page 228 Application Guide - NP900 Series 228 (504 Figure 3.3.2-104 Thermal image calculation with nominal conditions, example single time constant thermal replica. This described behavior is based into that assumption that the monitored object has a homogenous body which is generating and dissipating heat with a rate which is proportional to temperature rise caused by current squared.
Page 229 Application Guide - NP900 Series 229 (504 Amb<t × ( t ) � + k = � Amb<t × ( t ) � + 1.0 = � Amb>t Amb>t = Measured (set) ambient temperature (can be set in ̊ C or ̊ F ) = Maximum temperature (can be set in ̊...
Page 230 Application Guide - NP900 Series 230 (504 Settable thermal capacity curve uses linear interpolation for ambient temperature correction with maximum 10 pairs of temperature – correction factor pairs. Temperature and coefficient pairs are set to the TOLM function settable curve.
Page 231 Application Guide - NP900 Series 231 (504 stopped the cooling will stop also and the time constant is longer due to heat is dissipated to surrounding air slower. If the machine has active cooling then the cooling time constant may be the same with heating constant. Anyways in this case also the starting method (DOL / Soft start / YD) etc.
Page 232 Application Guide - NP900 Series 232 (504 Cables current carrying capacity is mostly depend of the cross section of the conductor diameter as well as the conductor material. Second most important factor is the insulating material of the cable and how much it can withstand temperature. As can be seen all...
Page 233 Application Guide - NP900 Series 233 (504 constant which is the same for heating and cooling, stator has own time constant where the heating time constant is different from the cooling constant and also the motor body has own time constant for heating and cooling. In the terms of protecting the motor from overloading the rotor and stator are the parts which require to be taken care from overheating.
Page 234 Application Guide - NP900 Series 234 (504 Motor is de-energized and all parts of it are in ambient temperature. When the motor is energized the stator generates magnetic field which induces voltage to the squirrel cage rotor. Now the rotor is not yet rotating and the...
Page 235 Application Guide - NP900 Series 235 (504 When the motor is run in nominal load for the time enough the temperatures to stabilize (5 x time constant) and the final temperatures are reached is said that the motor is running in its nominal temperature. Now the...
Page 236 Application Guide - NP900 Series 236 (504 Figure 3.3.2-111 Running motor temperature with thermal image camera. Rotor temperature measurement is very complicated due to its rotating nature and thus normally there are no measurements available and therefore the protection of rotor always needs to be taken care of with the calculated thermal image.
Page 237 Application Guide - NP900 Series 237 (504 Figure 3.3.2.1-112 Measured motor temperature in heating/cooling test. Figure 3.3.2.1-113 Matching of the thermal replicas to the measured thermal capacity of the motor. A996A...
Page 238 Application Guide - NP900 Series 238 (504 From the figure can be noted when the motor is loaded with constant current both of the replicas (single and dual time constant) follow the motor heating quite accurately. Difference in the operation comes from the cooling part. With single cooling time constant the replica does not follow the actual cooling of the motor and it can be said that the match is very poor.
Page 239 Application Guide - NP900 Series 239 (504 When the thermal limit curves are available for the motor the operation of the thermal replica can be set very accurately for the overloading and stall conditions. Figure 3.3.2.1-115 Single and dual time constant thermal replica tripping curves compared to given motor thermal characteristics.
Page 240 Application Guide - NP900 Series 240 (504 Figure 3.3.2.1-116 Thermal tripping curves with single time constant, preload 0% (cold) and 90% (hot). Figure 3.3.2.1-117 Thermal tripping curves with dual dynamic time constants and weighting factor, preload 0% (cold) and 90% (hot).
Page 241 Application Guide - NP900 Series 241 (504 Figure 3.3.2.1-118 Thermal cooling curves, single cooling time constant. Figure 3.3.2.1-119 Thermal cooling curves, dynamic dual time constant. A996A...
Page 242 Application Guide - NP900 Series 242 (504 Figure 3.3.2.1-120 Thermal cooling curves, dynamic triple time constant (motor is running without load in the first part with dedicated time constant). Figure 3.3.2.1-121 NPS biased thermal trip curves with kNPS values 1 and 3.
Page 243 Application Guide - NP900 Series 243 (504 Figure 3.3.2.1-122 NPS biased thermal trip curves with kNPS values 7 and 10. A996A...
Page 244 Application Guide - NP900 Series 244 (504 3.3.2.2 T HERMAL OVERLOAD FUNCTION Blocking signal and setting group selection controls the operating characteristics of the function during normal operation. Outputs of the function are TOLM Trip and Blocked signals. Setting parameters are static inputs for the function which are changed only by user input in the setup phase of the function.
Page 245 Application Guide - NP900 Series 245 (504 3.3.2.3 M EASURED INPUT VALUES Function block uses analog current measurements. Function uses the fundamental frequency magnitude of the current measurement inputs and calculated residual current with residual current measurement. For residual current measurement I01 or I02 channels can be selected.
Page 246 Application Guide - NP900 Series 246 (504 Table 3.3.2.3-154 Motor data settings. Name Range Step Default Prot.funcs. Description Motor In Scaled 0.1... 0.1xIn Motor nominal current scaled to per 40.0xIn TM> (49M) unit. If in the CT settings “Object In” is Ist>...
Page 247 Application Guide - NP900 Series 247 (504 No load current < 0.1…40.0xI 0.1xIn 0.2 xIn Motors no load current. This setting TM> (49M) defines the “Stopped” condition when I< (37) the current is below this setting value. Also below this value undercurrent protection stage is locked.
Page 248 Application Guide - NP900 Series 248 (504 3.3.2.3-155 Motor thermal image settings Name Range Step Default Description Pick-up current (xIn) 0.10…40.00 xIn 0.01 xIn 1.00 xIn Current for the 100 % thermal capacity to be used (pick-up current in p.u., with this current t will be achieved in time τ...
Page 249 Application Guide - NP900 Series 249 (504 of the motor cooling characteristics. If not known set it to same with Long Cool T const Stop for conservative setting or Long heat T const for faster cooling setting. (This setting is visible when “multiple”...
Page 250 Application Guide - NP900 Series 250 (504 (This setting is visible when “multiple” time constants is selected and also “Set manual” is selected for the “Estimate short TC and timings”). Wf factor for L/S T const 0.0…1.0 Weighting factor in between of the currently used long and short time constants.
Page 251 Application Guide - NP900 Series 251 (504 Table 3.3.2.3-156 Environmental settings Name Range Step Default Description Dev.Temp (tmax) Maximum allowed temperature for the protected object. Default setting is “F” which is +155 degrees centigrade. 4:Manual set Obj.Max.temp(tmax=100%) 0…500 deg 1 deg 125 deg Visible when the Dev.Temp.(tmax) is...
Page 252 Application Guide - NP900 Series 252 (504 Amb.Temp.ref1...10 -50.0…500.0 0.1 deg 15 deg Temperature reference points for the user settable ambient temperature coefficient curve. Setting is visible if Ambient lin. or curve is set to “Set curve”. Amb.Temp.k1...k10 0.01…5.00 1.00 0.01...
Page 253 Application Guide - NP900 Series 253 (504 The pick-up activation of the IO is direct for all other signals except TRIP signal which has also blocking check before the trip signal is generated. 3.3.2.5 F UNCTION BLOCKING In the blocking element the block signal is checked in the beginning of each program cycle.
Page 254 Application Guide - NP900 Series 254 (504 Table 3.3.2.6-159 Measurements Name Range Description / values Currents 0: Primary A Active phase current measurement from IL1(A), IL2(B) and 1: Secondary A IL3(C) phases in given scalings. 2: Per unit Thermal Image 0:Thermal image calc.
Page 255: Motor Start / Locked Rotor Monitoring (Lrc) I
Application Guide - NP900 Series 255 (504 Table 3.3.2.7-161. Event codes of the TOLM function instance Event Event Event Number channel Event block name Code Description 4288 67 TOLF1 0 Alarm1 On 4289 67 TOLF1 1 Alarm1 Off 4290 67 TOLF1...
Page 256 Application Guide - NP900 Series 256 (504 applications when the starting up may last long time and the starting situation should be checked that the motor is actually accelerating and not standing still with its rotor locked. Figure 3.3.3-124 Simplified function block diagram of the LRC function.
Page 257 Application Guide - NP900 Series 257 (504 Figure 3.3.3-125 Normal start of the motor. The LRC function should be set so that in the normal motor start the application required starting time is taken into account in the setting of the function. There should be setting margin in the expected starting time and the setting of the LRC function.
Page 258 Application Guide - NP900 Series 258 (504 Figure 3.3.3-126 Motor starting is too long. Reasons for too long starting may be in the drive and application as well as in the feeding network if started motor is very large and the feeding network is weak the voltage may drop so that the motor cannot provide needed torque for normal starting and the start-up situation is prolonged.
Page 259 Application Guide - NP900 Series 259 (504 Figure 3.3.3-127 Long start with speed switch available. Speed switch is useful also in cases if the motor start is naturally very long due to high accelerating mass. In such application it is impossible to note without speed switch if the startup is actually happening or if the load is jammed and the motor is standing still with its rotor locked.
Page 260 Application Guide - NP900 Series 260 (504 Figure 3.3.3-128 Motor start with speed switch, too long starting. If the starting condition lasts longer than the set safe stall time of the motor the LRC function will trip the breaker. In this case the motor is either too small to accelerate in time given for the motor for safe stall time or the load has some problem even the motor is able to rotate.
Page 261 Application Guide - NP900 Series 261 (504 Figure 3.3.3-129 Motor stall monitoring. 3.3.3.1 S ETTINGS AND SIGNALS Settings of the motor status monitor (MST) function are mostly shared with motor protection functions in the motor module of the IED. In following table are shown the functions which use these settings also.
Page 262 Application Guide - NP900 Series 262 (504 I< (37) Im> (50M) Nominal starting 0.1…40.0XIn 0.1xIn 6.0 xIn Motors locked rotor current with current TM> (49M) nominal voltage. This setting is used Ist> (48) for the automatic curve selection Im> (50M) and calculation.
Page 263 Application Guide - NP900 Series 263 (504 TM> (49M) this setting value is not exceed and Ist> (48) locked rotor situation occurs cold Im> (50M) stall curve adjusted with actual used thermal capacity is utilized. After this setting value hot stall curve is utilized.
Page 264 Application Guide - NP900 Series 264 (504 Table 3.3.3.1-165. Output signals of the MST function Name Range Step Default Description Ist> START 0=Not active Start output of the LRC function. This signal 1=Active activates when the starting conditions are met for the function and it is about to initiate trip after the time calculation is finished.
Page 265: Frequent Start Protection (Fsp) N> (66)
Application Guide - NP900 Series 265 (504 3.3.4 F (FSP) N> (66) REQUENT START PROTECTION Frequent start protection (FSP) function is used for monitoring and preventing too frequent starting of the motor. This function monitors the used starts of the motor in given time so that the start stress is not exceeding the manufacturer given limits.
Page 266 Application Guide - NP900 Series 266 (504 Operating principle of the FSP function is to calculate in each start a equivalent start stress given by the set starts per hour and safe stall time settings (hot and cold) regardless of the actual start duration. In each start attempt time equivalent to safe stall time is added to the starts counter which is then deduct by the safe stall time divided by given starts time in hours.
Page 267 Application Guide - NP900 Series 267 (504 Figure 3.3.4-132 FSP Starts counter update when thermal hot and cold status is considered. If the motor thermal load is monitored, the available starts can be updated on-line in the IED and the precise follow up of the motor status can be monitored and correct amount of starts can be allowed for the motor.
Page 268 Application Guide - NP900 Series 268 (504 3.3.4.1 S ETTINGS AND SIGNALS Settings of the frequent start protection (FSP) function are directly the given motor data from the motor module of the IED. In following table are shown the functions which use these settings also.
Page 269 Application Guide - NP900 Series 269 (504 Table 3.3.4.1-169. Output signals of the FSP function Name Range Step Default Description N> Alarm on 0=Not active Alarm output of the FSP function. This 1=Active signal activates when there is 1 start available for the motor.
Page 270: Under Current I< (37)
Application Guide - NP900 Series 270 (504 3.3.5 U I< (37) NDER CURRENT Undercurrent function (NUC) is used for monitoring motor loading especially in conveyor type of applications. If the motor load is suddenly lost it indicates problems in the actual load rather than in the motor itself.
Page 271 Application Guide - NP900 Series 271 (504 In the following figure is presented the simplified function block diagram of the NUC function. Figure 3.3.5-133 Simplified function block diagram of the NUC function. 3.3.5.1 M EASURED INPUT VALUES For the function block is used analog current measurement values. Function block utilizes fundamental frequency phase current RMS measurements.
Page 272 Application Guide - NP900 Series 272 (504 Table 3.3.5.2-173 Motor data settings of the NUC function Name Range Step Default Prot.funcs. Description Motor In Scaled 0.1... 40.0xIn 0.1xIn Motor nominal current scaled to per TM> (49M) unit. If in the CT settings “Object In”...
Page 273 Application Guide - NP900 Series 273 (504 From blocking of the function a HMI display event as well as time stamped blocking event with information of the startup current values and fault type is issued. Blocking signal can be tested also in the commissioning phase of the stage by software switch signal when relay common and global testing mode is activated.
Page 274: Mechanical Jam Protectioni
Application Guide - NP900 Series 274 (504 3.3.6 M > (51M) ECHANICAL JAM PROTECTION Mechanical jam protection (MJP) is used for monitoring motor loading after starting of the motor. In cases if the motor run apparatus jams during the work load the mechanical jam protection can be used to disconnect the motor from the feeding network in order to avoid further damage to the motor drive.
Page 275 Application Guide - NP900 Series 275 (504 Figure 3.3.6-134 Simplified function block diagram of the MJP function. 3.3.6.1 M EASURED INPUT VALUES For the function block is used analog current measurement values. Function block utilizes fundamental frequency phase current RMS measurements. For the pre-fault data registering is used -20 ms averaged value of the selected magnitude.
Page 276 Application Guide - NP900 Series 276 (504 Table 3.3.6.2-178 Motor data settings of the MJP function Name Range Step Default Prot.funcs. Description Motor In Scaled 0.1... 40.0xIn 0.1xIn Motor nominal current scaled to per TM> (49M) unit. If in the CT settings “Object In”...
Page 277 Application Guide - NP900 Series 277 (504 Ist> (48) Im> (50M) Hot condition 0.0…100.0% 0.1% Setting of the thermal limit Hot / theta limit N> (48) Cold situation of the motor. When TM> (49M) this setting value is not exceed and Ist>...
Page 278 Application Guide - NP900 Series 278 (504 Table 3.3.6.2-180 Operating time characteristics setting parameters. Name Range Step Default Description Definite operating 0.000…1800.000 s 0.005 s 0.040 s Definite time operating delay. Setting is time delay active and visible when Delay Type is selected to DT.
Page 279 Application Guide - NP900 Series 279 (504 If blocking signal is active when pick-up element activates a BLOCKED signal will be generated and the function shall not process the situation further. If START function has been activated before blocking signal it will reset and the release time characteristics are processed as in case of when pick-up signal is reset.
Page 280: Resistance Temperature Detectors (Rtd) (49T)
Application Guide - NP900 Series 280 (504 Table 3.3.6.4-183. Register content. Date & Time Event Fault Trigger Fault Prefault Trip time Used code type current current current remaining dd.mm.yyyy 3776- L1-G… Start Trip Start 0 ms - 1 - 8 hh:mm:ss.mss...
Page 281 Application Guide - NP900 Series 281 (504 Figure 3.3.7-136 Communication settings for the RTD module. After the communication is set the wanted channels are selected from the ModbusIO tab under “Protocols”. There are three separate modules available for selection. Figure 3.3.7-137 Set up of the measurement module.
Page 282 Application Guide - NP900 Series 282 (504 Figure 3.3.7-138 RTD alarm set up. In the motor module RTD alarm function can be set to monitor previously set RTD channels measurement data. A single channel can be set to have several alarms by selecting the channel to multiple sensor inputs.
Page 283 Application Guide - NP900 Series 283 (504 degrees. Sx sensor Display of the measured sensor data validity. If Invalid the sensor reading has any problems the sensor data is set to “Invalid” and the alarms are not activated. Sx Enable alarm 1...
Page 284 Application Guide - NP900 Series 284 (504 Table 3.3.7.2-185. Event codes of the RTD alarms Event Event Event Number channel Event block name Code Description 4416 69 RTD1 0 S1 Alarm1 On 4417 69 RTD1 1 S1 Alarm1 Off 4418...
Page 285: Generator Protection Module
Application Guide - NP900 Series 285 (504 3.4 G ENERATOR PROTECTION MODULE 3.4.1 M (49M) ACHINE THERMAL PROTECTION See chapter 3.3.2 in Motor protection module 3.4.2 U Q< (40) NDER EXCITATION Synchronous machines require a certain minimum excitation in order to stay stable. If the excitation drops too low synchronous machine can drop out of step.
Page 286 Application Guide - NP900 Series 286 (504 Below is presented the formula for three phase reactive power (Q) calculation when line- to-neutral voltages are available: × I sin φ Where, × I sin φ UL1…UL3 = Line to neutral voltage ×...
Page 287 Application Guide - NP900 Series 287 (504 Figure 3.4.2-141 Simplified function block diagram of the UEX function. 3.4.2.1 M EASURED INPUT VALUES Three phase reactive power value is used for the function block. -20ms averaged value is used for pre-fault data registering.
Page 288 Application Guide - NP900 Series 288 (504 Table 3.4.2.2-187 Pick-up characteristics setting Name Range Step Default Description Qset mode Fixed Fixed Decision if the pick-up area P dependent is defined only by Qset< parameter or by two points set in the PQ-plane.
Page 289 Application Guide - NP900 Series 289 (504 User settable variables are binary signals from the system. Blocking signal needs to reach the IED minimum of 5 ms before the set operating delay has passed for blocking to be active in time.
Page 290: Under Impedance Z< (21G)
Application Guide - NP900 Series 290 (504 3.4.3 U Z< (21G) NDER IMPEDANCE Underimpedance protection is an alternative for voltage restrained overcurrent protection (also included in the NPG915 model) which can be used to detect short circuit faults near the generator even when the short circuit current is small.
Page 291 Application Guide - NP900 Series 291 (504 calculated impedance per all three stages or positive sequence impedance. Reset ratio of 103 % is inbuilt in the function and is always related to the current pick-up value. Table 3.4.3.2-191 Pick-up characteristics setting...
Page 292: Voltage Restrained Overcurrent (51V)
Application Guide - NP900 Series 292 (504 12 last registers are available in the function where the triggering event of the function (start, trip or blocked) is recorded with time stamp and process data values. Table 3.4.3.4-192. Event codes of the UIM function.
Page 293 Application Guide - NP900 Series 293 (504 Figure 3.4.4-143 Pick-up level in voltage restrained overcurrent mode and voltage controlled overcurrent mode. Just like the other overcurrent protection functions this function can be set to inverse curves or definite time delay. But if in this functions case inverse time delay is selected, the time delay depends on the ratio between the measured current and the current pick- up level at the moment.
Page 294 Application Guide - NP900 Series 294 (504 whole harmonic specter of 32 components or peak to peak values. For the pre-fault data registering -20 ms averaged value of the selected magnitude is used. Table 3.4.4.1-193 Measurement magnitudes used by the VOC function.
Page 295 Application Guide - NP900 Series 295 (504 3.4.4.3 F UNCTION BLOCKING In the blocking element the block signal is checked at the beginning of each program cycle. Blocking signal is received from the blocking matrix for the function dedicated input.
Page 296: Volts-Per-Hertz Over Excitation (24)
Application Guide - NP900 Series 296 (504 Table 3.4.4.5-195. Event codes of the VOC function. Event Event Event Event Alarm Number channel Event block name Code Description Type Type 6784 106 VOC1 0 Start ON 6785 106 VOC1 1 Start OFF...
Page 297 Application Guide - NP900 Series 297 (504 function. Overexcitation function utilizes total of eight separate setting groups which can be selected from one common source. The operational logic consists of input magnitude processing, input magnitude selection, threshold comparator, block signal check, time delay characteristics and output processing.
Page 298 Application Guide - NP900 Series 298 (504 Table 3.4.5.2-198 Pick-up characteristics setting Name Description Range Step Default Pick-up V/Hz > Maximum allowed measured V/Hz 0.01 … 30.00% 0.01% 5.00% nominal ratio increase to nominal V/Hz ratio. Delay type Selected delay type...
Page 299 Application Guide - NP900 Series 299 (504 Figure 3.4.5.2-145 Inverse and inverse with definite time characteristics with the TimeDial k setting effect. A996A...
Page 300 Application Guide - NP900 Series 300 (504 Figure 3.4.5.2-146 Inverse and inverse with definite time characteristics with the IDMT multiplier setting effect. Table 3.4.5.2-199 Reset time characteristics setting parameters. Release Time 0.000…150.000 s 0.005 s 0.06 s Resetting time. Time allowed in between...
Page 301 Application Guide - NP900 Series 301 (504 Resetting characteristics can be set according to the application. Default setting is delayed with 60 ms and the time calculation is held during the release time. When using the release delay option where the operating time counter is calculating the operating time during the release time, function will not trip if the input signal is not activated again during the release time counting.
Page 302: Stator Earth Fault (64S)
Application Guide - NP900 Series 302 (504 Table 3.4.5.4-200. Event codes of the VHZ function instance. Event Event Event Event Number channel Event block name Code Description Type 8192 128 VHZ1 0 Start ON 8193 128 VHZ1 1 Start OFF...
Page 303 Application Guide - NP900 Series 303 (504 Figure 3.4.6-147 Demonstration of the overlapping range of neutral overvoltage and 100% stator earth fault protection. Inputs for the function are the operating mode selections, setting parameters and measured and pre-processed voltage and current magnitudes and binary input signals.
Page 304 Application Guide - NP900 Series 304 (504 Figure 3.4.6-148 Simplified function block diagram of the SEF function. 3.4.6.1 M EASURED INPUT VALUES Function block uses analog voltage measurement values for third harmonic voltage measurement and three phase current measurement for positive sequence current blocking.
Page 305 Application Guide - NP900 Series 305 (504 Table 3.4.6.2-203 Pick-up characteristics setting Name Description Range Step Default Uset< Pick-up setting 1.00 … 100.00 %U 0.01 %U 20 %U I1< If measured 0.00…100.00 *In 0.01 *In 0 %Un block positive sequence...
Page 306 Application Guide - NP900 Series 306 (504 3.4.6.4 O PERATING TIME CHARACTERISTICS FOR TRIP AND RESET This function supports definite time delay (DT). For detailed information on this delay type refer to chapter General properties of a protection function. 3.4.6.5 E...
Page 307: Transformer Protection Module
Application Guide - NP900 Series 307 (504 3.5 T RANSFORMER PROTECTION MODULE 3.5.1 T RANSFORMER STATUS MONITORING FUNCTIONS Transformer status monitoring function (TRF) is designed to be the common place for set up all necessary transformer data and to select the used transformer protection functions.
Page 308 Application Guide - NP900 Series 308 (504 The TRF function outputs are dependent of the set transformer data in that sense that per unitized measured currents are related to transformer nominal values. In following diagram are presented the TRF function outputs in different kind of situations.
Page 309 Application Guide - NP900 Series 309 (504 Table 1.1.1.1-206 Settings of the TRF function. Name Range Step Default Funcs. Description Transformer 0.1… 0.1MV 1.0MVA Nominal MVA of transformer. nominal MVA 500.0 MVA This value is used to calculate nominal currents of HV, and LV side.
Page 310 Application Guide - NP900 Series 310 (504 HV side lead or 0:Lead 0:Lead TRF, DIFF Selection for HV side leads or lag LV 1:Lag lags LV side. Selection is visible only if vector group is set to “0:Manual set” LV side Star or...
Page 311 Application Guide - NP900 Series 311 (504 Table 1.1.1.1-207 Calculations of the TRF function. Name Range Step Default Funcs. Description HV side nominal 0.01… 0.01A 0.00A Info Calculated transformer HV current(pri) 50000.00A side primary current. HV side nominal 0.01… 0.01A 0.00A...
Page 312 Application Guide - NP900 Series 312 (504 Table 1.1.1.1-208. Output signals of the TRF function Name Range Step Default Description No/Light load 0=Not active Signal is active, when the TRF function 1=Active detects current below “No load current”. This signal presents situation when there is very light load or only one or neither side of trafo is energized.
Page 313: Differential Protection Id> (87)
Application Guide - NP900 Series 313 (504 In the table below is presented the structure of TRF function register content. This information is available in 12 last recorded events. Table 1.1.1.2-210. Register content. Date & Time Event HVL1 HVL2 HVL3...
Page 314 Application Guide - NP900 Series 314 (504 Transformer Risks Protection Pole mount < 100 kVA Mostly environmental, highest risk is Feeder overcurrent and earth fault transformer lightning hit to overhead line. If broken, protection, no separate protection changing to new in hours is possible.
Page 315 Application Guide - NP900 Series 315 (504 and faults in cooling systems. These reasons can cause transformer windings earth faults, interturn faults or even phase to phase faults. 1.1.1.3 W DIFFERENTIAL PROTECTION NEEDED TRANSFORMER PROTECTION Transformer differential function is based into calculation of ingoing and outgoing current difference, e.g.
Page 316 Application Guide - NP900 Series 316 (504 On the other hand differential protections negative properties are that it is not the easiest to set up to operate correctly and second set of current transformers are required thus increasing the installation cost. In bigger scale power transformers this still is marginal cost.
Page 317 Application Guide - NP900 Series 317 (504 1.1.1.4-152 Transformer name-plate data. From the name plate data can be seen that this transformer is designed for three phase usage and it has two windings. Nominal design power of the transformer is 2 MVA and its vector group is Yd1 which means that the HV side is connected to star and LV side to delta so that the LV side has 30 degree lag to HV side.
Page 318 Application Guide - NP900 Series 318 (504 Primary side per unit factor and current calculation 2000000VA = 115.47 A √ 3 × U √ 3 × 10000V 115.47A IpuPRI = 0.77 CTpri 150 A IpuSEC = IpuPRI × CTsec = 0.77 × 5A = 3.85 A...
Page 319 Application Guide - NP900 Series 319 (504 Figure 1.1.1.4-153 Amplitude scaling to match the nominal currents and CTs in the differential relay. Nominal current matching is only part of the differential protection settings. Also the vector group of the transformer is important, since differential function is interested in the angle difference of the measured current vectors.
Page 320 Application Guide - NP900 Series 320 (504 Figure 1.1.1.4-154 Yd1 transformer internal connection in principle. In modern relays these standard vector groups (wye, delta, lead or lag) are defined by a setting selection and there is no need for interposing transformers. If the transformer vector group is not standard it should still be settable within the relay (in case of zigzag transformers).
Page 321 Application Guide - NP900 Series 321 (504 then current should flow to relay input and if there is enough difference it would cause pick-up and trip. This is not the case with NP900 differential relay, which does this transformation by calculating internally the corrected vectors.
Page 322 Application Guide - NP900 Series 322 (504 | IL1 | + | IL1 L1BIAS | IL2 | + | IL2 L2BIAS | IL3 | + | IL3 L3BIAS Max mode (coarse biasing): = max ( | IL1 | , | IL1...
Page 323 Application Guide - NP900 Series 323 (504 Diff = SL1 × ( TP2-TP1 ) + I Bias TP1…TP2 d>Pick-up Diff = SL2 × ( Ix-TP2 ) + SL1 × ( TP2-TP1 ) + I Bias>TP2 d>Pick-up , thus forming a straight line from zero current to TP1 (Turn point 1). From there to TP2 (Turn point 2) is the first slope which causes the set biasing to be more coarse when the measured current amplitude increases.
Page 324 Application Guide - NP900 Series 324 (504 Figure 1.1.1.5-156 Natural differential current sources. Differential current sources in normal operation: Primary side CT measurement accuracy (CTE pri) Secondary side CT measurement accuracy (CTE sec) Relay measurement accuracy (primary and secondary) (REm)
Page 325 Application Guide - NP900 Series 325 (504 REm: Relay measurement error is below 0.5% and with optional accuracy below 0.2% per measurement channel, so this value for both sides combined is either 1% or 0.4%. TCE: In this example transformer there is tap changer with rating of +/- 5 x 2.5% which means that from nominal center position the secondary side windings can be set to + 5 x 2.5% or -5 x 2.5% position causing deviation max of 5 x 2.5% from the nominal conditions.
Page 326 Application Guide - NP900 Series 326 (504 AUTE: In this example there is 50kVA auxiliary transformer connected to the LV side output before the CTs so it has to be taken into account for the differential base sensitivity calculations. Same goes if in the transformer itself is found auxiliary power output and its currents are not measured.
Page 327 Application Guide - NP900 Series 327 (504 changer is in maximum position thus causing the absolute measurement to be 1 xIn + CTEpri + CTEsec + TCE + CTEsec × TCE IMEAS × 100 1 + TCE With our example configuration the calculation would be: 0.1 + 0.05 + 0.125 + (0.05 ×...
Page 328 Application Guide - NP900 Series 328 (504 This can lead to optimal sensitivity and stabile settings for differential relay even there is no non biased sensitive section in the characteristics. d>Pick-up In this case the base sensitivity setting should be set as follows: = CTEpri + CTEsec + 2 ×...
Page 329 Application Guide - NP900 Series 329 (504 Next is calculated the currents flowing in this situation at HV and LV sides, when the loading of the transformer is e.g. 1.5 times its rated power. For LV side currents will be ×...
Page 330 Application Guide - NP900 Series 330 (504 Idiff TP2 1.5-1.7 Slope 1 = × 100% = × 100% = × 100% = 11.7% max ( ⌊ I ⌋ , ⌊ I ⌋ ) LxBIAS Now to be on safe side for this may be added yet another safety margin if so wished (even the base sensitivity settings include 5% already) to ensure stability.
Page 331 Application Guide - NP900 Series 331 (504 Setting of the stage should be based into the weakest CT full saturation under worst case through fault condition (since this causes that only the other side current is measured then and that causes all seen current to be differential current).
Page 332 Application Guide - NP900 Series 332 (504 Important initial data for this check is the VA of the CTs on both sides, how long wiring to relay from the CTs, what is the cross-section and material of the wires and how the CTs are connected.
Page 333 Application Guide - NP900 Series 333 (504 These values were calculated with R ρ×l Cond formula. Suggestion is that for calculating the CT burden the worst case scenario is used. For most cases these 75℃ values can be used. If in your application ambient temperature is higher than 75℃, then the resistance should be calculated for that temperature.
Page 334 Application Guide - NP900 Series 334 (504 typical relay application comes from the wirings. If the secondary burden is known then of course it should be used (some CT manufacturers include this information in their end test documentation). In this example let’s assume for the HV side CT the internal resistance to be 0.05Ω, it is rated 5VA and for the LV CT internal resistance to be 0.09Ω...
Page 335 Application Guide - NP900 Series 335 (504 20.2 xIn. In the LV side also the maximum output current will be 20.2 xIn when the LV side CT is able to repeat 23.5 xIn current. From this notation can be expected that the through fault will not be causing problems with this power transformer and CT combination.
Page 336 Application Guide - NP900 Series 336 (504 Figure 1.1.1.5-158 When everything is set up correctly in the relay and when the transformer is feeding the load with nominal power the result should look like this with the example settings and transformer.
Page 337 Application Guide - NP900 Series 337 (504 Basically in between these presented restraint calculation modes the characteristics are now set to equally sensitive. Also the variations of Turnpoint1 setting either to 0.01xIn or 1.0xIn are presented (Figures A, C with Turnpoint 1 set to 1.00 xIn and B, D with Turnpoint 1 set to 0.01 xIn).
Page 338 Application Guide - NP900 Series 338 (504 relay and for that the vector group selection of the transformer setup has either “N” or “n” representing either HV side or LV side grounding. What this selection actually does is that it deducts the calculated zero sequence current from the per-unitized currents before differential calculation thus negating the outside earth fault effect.
Page 339 Application Guide - NP900 Series 339 (504 ��⃗ + IL2 ��⃗ + IL3 ��⃗ ��⃗ ��⃗ - = IL2 Corr ��⃗ + IL2 ��⃗ + IL3 ��⃗ ��⃗ ��⃗ - = IL3 Corr Important note!: By enabling the zero sequence compensation by selecting the “N” or “n”...
Page 340 Application Guide - NP900 Series 340 (504 For HV side: ��⃗ ��⃗ ��⃗ ) + I0 ��⃗ �( IL1 + IL2 + IL3 � HVMEAS I0d_Bias_AVG ��⃗ ��⃗ ��⃗ � , I0 ��⃗ = max�( IL1 + IL2 + IL3...
Page 341 Application Guide - NP900 Series 341 (504 CTs and the desired sensitivity for internal fault close to neutral and the Turnpoint 1 setting up to 2 x CT in. Normally the neutral point CT is with lower primary current rating than phase current CTs so it’s primary to maximum current rating should be the guiding...
Page 342 Application Guide - NP900 Series 342 (504 When a power transformer primary side is energized (secondary side open) transformer π can be considered as a simple inductance. In normal operation of transformer the flux produced in the transformer core is lagging the fed voltage by radians (90 deg).
Page 343 Application Guide - NP900 Series 343 (504 Figure 1.1.1.8-161 Transformer energization magnetizing inrush. In the figure above is presented small transformer energizing behavior, where the first curve from top is the applied voltage, second are phase currents peak and FFT values...
Page 344 Application Guide - NP900 Series 344 (504 As can be seen that the magnetizing inrush with this small transformer (2MVA used in the previous example also) is very short, about 7 seconds, there is still over the nominal measurable current which is seen only in the primary side of the transformer thus would cause clearly tripping of the differential relay if tried to energize without magnetizing inrush blocking.
Page 345 Application Guide - NP900 Series 345 (504 Now this result is still very low considering of the magnetizing inrush current magnitudes but still the differential relay would definitely trip in this case if it would not be prevent from operating by 2 harmonic blocking.
Page 346 Application Guide - NP900 Series 346 (504 Figure 1.1.1.8-163 Inrush blocking by using 2 harmonic related to fundamental frequency component. Figure 1.1.1.8-164 Example of transformer magnetizing inrush currents. As conservative setting suggestion for standard type transformer could be recommended harmonic blocking enabled with sensitivity set to around 15-20% harmonic content compared to fundamental frequency.
Page 347 Application Guide - NP900 Series 347 (504 Harmonic for over excitation block, principle and usage. When the transformer primary side voltage increases for some reason (V/f) ratio is higher than designed, transformer will over excite very rapidly. Reasons for this event may be that the LV side fault causes the loading to be thrown off suddenly causing temporary overvoltage or in the network frequency goes down for some reason e.g.
Page 348 Application Guide - NP900 Series 348 (504 suggested setting limits for the 5 harmonic detection (30%, 35% and 40%). In the second graph are plotted primary and secondary currents in function of the voltage and in the last graph the differential characteristics and differential/bias currents.
Page 349 Application Guide - NP900 Series 349 (504 could be more of use the magnetizing properties and hysteresis of the transformer should be completely known. Figure 1.1.1.8-167 Per unitized system voltage and magnitude of the 5 harmonic component, absolute and scaled to transformer nominal.
Page 350 Application Guide - NP900 Series 350 (504 1.1.1.9 D IFFERENTIAL FUNCTION DETAILS Figure 1.1.1.9-168 Simplified function block diagram of the DIF function. Differential function outputs the trip and blocked signals from the biased and non biased functions as well as the 2 and 5 harmonic blocks activation signals.
Page 351 Application Guide - NP900 Series 351 (504 Table 1.1.1.10-211 Settings related to DIF function pre calculation. Name Range Step Default Funcs. Description Transformer 0.1… 0.1MV 1.0MVA Nominal MVA of transformer. nominal MVA 500.0 MVA This value is used to calculate nominal currents of HV, and LV side.
Page 352 Application Guide - NP900 Series 352 (504 Table 1.1.1.10-212 Settings related to DIF function pre calculation. (continued). Name Range Step Default Funcs. Description HV side grounded 0:Not 0:Not TRF, DIFF Selection whether the zero grounded grounded sequence compensation 1:Grounded should be applied into HV side currents calculation.
Page 353 Application Guide - NP900 Series 353 (504 Table 1.1.1.10-213 Settings related to DIF function pre calculation. (continued). Name Range Step Default Funcs. Description Enable I0d> 0:Disabled 0: Disabled TRF,DIFF LV side restricted earth fault (REF) LV side 1:Enabled stage enable/disable selection.
Page 354 Application Guide - NP900 Series 354 (504 earthfault differential characteristics Setting is visible only if “Enable I0d> (REF) HV side” is set to “1: Enabled” HV I0d> Turnpoint 1 0.01…50.00xIn 0.01xIn 1.00xIn Turnpoint 1 for the HV side restricted earthfault differential characteristics Setting is visible only if “Enable I0d>...
Page 355 Application Guide - NP900 Series 355 (504 Table 1.1.1.10-215 Calculations of the DIF function. Name Description L1Bias Calculated phase L1 Bias current L2Bias Calculated phase L2 Bias current L3Bias Calculated phase L3 Bias current L1Diff Calculated phase L1 Differential current...
Page 356 Application Guide - NP900 Series 356 (504 1.1.1.11 E VENTS DIF function generates events from internal status changes. From changes of the tripping events also data register is available. Table 1.1.1.11-217. Event codes of the DIF function. Event Event Event...
Page 357: Thermal Overload For Transformer (49T)
Application Guide - NP900 Series 357 (504 In the table below is presented the structure of DIF function register content. This information is available in 12 last recorded events. Table 1.1.1.11-219. Register content. Date & Time Event L1 Bias L1 Diff...
Page 358 Application Guide - NP900 Series 358 (504 Thermal image for the TOLT function is calculated according to equation described below: θ = ��θ - � � × e � + � � � × 100% × k × k τ...
Page 359 Application Guide - NP900 Series 359 (504 Figure 3.5.3-169 Thermal image calculation with nominal conditions, example. This described behavior is based into that assumption that the monitored object, whether cable, line or electrical device has a homogenous body which is generating and dissipating heat with a rate which is proportional to temperature rise caused by current squared.
Page 360 Application Guide - NP900 Series 360 (504 Ambient temperature compensation takes into account the set minimum and maximum temperature and load capacity of the protected object and measured or set ambient temperature. The calculated coefficient is linear correction factor which is presented with following formulas: Amb<t...
Page 361 Application Guide - NP900 Series 361 (504 3.5.3.1 T HERMAL OVERLOAD FUNCTION Blocking signal and setting group selection controls the operating characteristics of the function during normal operation. Outputs of the function are TOLT Trip and Blocked signals. Setting parameters are static inputs for the function which are changed only by user input in the setup phase of the function.
Page 362 Application Guide - NP900 Series 362 (504 3.5.3.2 M EASURED INPUT VALUE For the function block is used analog current measurement values. Function uses the fundamental frequency magnitude of the current measurement inputs and calculated residual current with residual current measurement. For residual current measurement can be selected I01 or I02.
Page 363 Application Guide - NP900 Series 363 (504 Table 3.5.3.2-224 Environmental settings Name Range Step Default Description Object max temp (tmax = 0…500 deg 1 deg Maximum allowed temperature for 100%) the protected object. Default setting is +90 degrees and it suits for Celsius...
Page 364 Application Guide - NP900 Series 364 (504 Ambient lin. or curve is set to “Set curve”. Amb.Temp.k1...k10 0.01…5.00 1.00 0.01 Coefficient value for the temperature reference point. Coefficient and temperature reference points must be set as pairs. Setting is visible if Ambient lin.
Page 365 Application Guide - NP900 Series 365 (504 3.5.3.4 F UNCTION BLOCKING In the blocking element the block signal is checked in the beginning of each program cycle. Blocking signal is received from the blocking matrix for the function dedicated input.
Page 366 Application Guide - NP900 Series 366 (504 Table 3.5.3.5-227 Measurements Name Range Description / values Currents 0: Primary A Active phase current measurement from IL1(A), IL2(B) and 1: Secondary A IL3(C) phases in given scalings. 2: Per unit Thermal Image 0:Thermal image calc.
Page 367: Volts-Per-Hertz Over Excitation (24)
Application Guide - NP900 Series 367 (504 Table 3.5.3.6-229. Event codes of the TOLT function instance Event Event Event Number channel Event block name Code Description 4672 73 TOLT1 0 Alarm1 On 4673 73 TOLT1 1 Alarm1 Off 4674 73 TOLT1...
Page 368: Control Functions
(SGS) ETTING GROUP SELECTION Eight (8) separate setting groups are available in in NP900 series devices. Availability and selection is controlled by SGS function block. By default only SG1 is active and thus the selection logic is idle. When more than one setting group is enabled the setting group selector logic shall take control of the setting group activations based into the user programmed logic and conditions.
Page 369 Application Guide - NP900 Series 369 (504 device automatic control is overridden and full control of setting group is with user until the force SG change is disabled again. For the application controlled setting group switch and selection is available either pulse controlled change or signal level change options.
Page 370 Application Guide - NP900 Series 370 (504 Table 3.6.1.1-231 Settings of the SGS function. Name Range Step Default Description Used setting 0=SG1 Selection of activated setting groups in the groups 1=SG1...2 application. If setting group is enabled it 2=SG1...3 cannot be controlled to active. When 3=SG1...4...
Page 371 Application Guide - NP900 Series 371 (504 Table 3.6.1.1-232. Signals of the SGS function Name Range Step Default Description Setting group 1 0=Not active Setting group 1 selection, highest priority 1=Active input for setting group control. Can be controlled with pulse or steady state signals.
Page 372 Application Guide - NP900 Series 372 (504 3.6.1.2 E VENTS SG selection function block generates events from its controlling status and applied input signals as well as unsuccessful control changes and enabled setting groups. For this function is no register available.
Page 373 Application Guide - NP900 Series 373 (504 3.6.1.3 E XAMPLES OF ETTING GROUP CONTROL In this chapter are presented some of most common applications for setting group changing requirements. In a Petersen coil compensated network is usually used directional sensitive earth fault...
Page 374 Application Guide - NP900 Series 374 (504 Figure 3.6.1.3-175 Setting group control with 2 wire connection from Petersen coil status. Figure 3.6.1.3-176 Setting group control with 2 wire connection from Petersen coil status and additional logic. A996A...
Page 375 Application Guide - NP900 Series 375 (504 Application controlled setting group change can be applied also completely from the relays internal logics. One example can be setting group change based into cold load pick up function. Figure 3.6.1.3-177 Example of fully application controlled setting group change with CLPU function.
Page 376: Object Control And Monitoring (Obj)
Application Guide - NP900 Series 376 (504 3.6.2 O (OBJ) BJECT CONTROL AND MONITORING Object control and monitoring function takes care of circuit breaker and disconnector controlling and status monitoring. Monitor and control is based into the statuses of the IED binary inputs and outputs configured.
Page 377 Application Guide - NP900 Series 377 (504 Figure 3.6.2-179 Simplified function block diagram of the OBJ function. 3.6.2.1 I NPUT SIGNALS FOR OBJECT STATUS MONITORING For the function is used available hardware and software digital signal statuses and command signals. The signals can be divided into Monitor, Command and Control signals based into how they are dealt in the function.
Page 378 Application Guide - NP900 Series 378 (504 Syncrocheck DI1 … DIx Link to the physical binary input or synchrocheck function.“1” means that the permission (SWx) synchrocheck conditions are met and object can be closed. Position indication can be done among binary inputs and protection stage signals by using IEC- 61850, GOOSE or logical signals.
Page 379 Application Guide - NP900 Series 379 (504 Table 3.6.2.1-236 Control digital signal outputs used by the OBJ function. Signal Range Description Close OUT1…OUTx Physical close command pulse to output relay of the IED. command Open OUT1…OUTx Physical open command pulse to output relay of the IED command 3.6.2.2 S...
Page 380 Application Guide - NP900 Series 380 (504 Table 3.6.2.2-238 Object setting parameters Name Range Step Default Description Object type Withdrawable CB User selection of object type. Selection defines the Circuit Breaker amount of required binary inputs for the monitored Disconnector (MC) object.
Page 381 Application Guide - NP900 Series 381 (504 3.6.2.3 B LOCKING AND INTERLOCKING For each controllable object can be set interlocking and blocking conditions for open and close separately. Blocking and interlocking can be based into other object statuses, software function or binary input. For example interlocking can be set for object close based into earthing disconnector position.
Page 382 Application Guide - NP900 Series 382 (504 Table 3.6.2.4-239. Event codes of the OBJ function instances 1 – 5. Event Event Event Event Number channel Event block name Code Description Type 2945 OBJ1 Object Intermediate 2946 OBJ1 Object Open 2947...
Page 383 Application Guide - NP900 Series 383 (504 3073 OBJ3 Object Intermediate 3074 OBJ3 Object Open 3075 OBJ3 Object Close 3076 OBJ3 Object Bad 3077 OBJ3 WD Intermediate 3078 OBJ3 WD Out 3079 OBJ3 WD in 3080 OBJ3 WD Bad 3081...
Page 384 Application Guide - NP900 Series 384 (504 3205 OBJ5 WD Intermediate 3206 OBJ5 WD Out 3207 OBJ5 WD in 3208 OBJ5 WD Bad 3209 OBJ5 Open Request On 3210 OBJ5 Open Fail 3211 OBJ5 Open Request Off 3212 OBJ5 Open Command On...
Page 385: Synchro-Check Function Δf, Δu, Δφ
Application Guide - NP900 Series 385 (504 Object registers are treated different from other registers seen in the IED. Following example is from closing of the breaker when the breaker is not ready. dd.mm.yyyy hh:mm:ss.mss ObjectOpen, WDIn, Close request from RemCloInput,Close pending due to: Close wait for Ready, Open Allowed, Close Allowed, Object Not Ready dd.mm.yyyy hh:mm:ss.mss ObjectOpen,WDIn,Open Allowed,Close Allowed,ObjectReady...
Page 386 Application Guide - NP900 Series 386 (504 Figure 3.6.3-1 Example connection of synchrocheck function in 3LN+U4 mode when the SYN1 stage is in use and UL1 is the reference voltage. Figure 3.6.3-2 Example connection of synchrocheck function in 2LL+U3+U0 mode when the SYN2 stage is in use and UL12 is the reference voltage.
Page 387 Application Guide - NP900 Series 387 (504 Figure 3.6.3-3 Example connection of synchrocheck function in 2LL+U3+U4 mode when the SYN3 stage is in use and UL12 is the reference voltage. A996A...
Page 388 Application Guide - NP900 Series 388 (504 Figure 3.6.3-4 Example application of synchrocheck over one breaker in 3LL and 3LN VT connection situations. A996A...
Page 389 Application Guide - NP900 Series 389 (504 Figure 3.6.3-5 Example application of synchrocheck over one breaker with 2LL VT connection. A996A...
Page 390 Application Guide - NP900 Series 390 (504 Figure 3.6.3-6 Example application of synchrocheck over two breakers in 2LL+U3+U4 mode. Reference of the U3 or U4 voltages may be U12, U23 or U31. A996A...
Page 391 Application Guide - NP900 Series 391 (504 Figure 3.6.3-7 Example application of synchrocheck over three beakers (only in available 2LL+U3+U4 VT connection). Reference of the U3 and U4 channels must be the same (U12, U23 or U31). The two systems are synchronized when three aspects of the compared voltages are matched which are magnitudes of the voltages, frequencies of the voltages and phase angles of the voltages.
Page 392 Application Guide - NP900 Series 392 (504 used to determine which conditions have to be met in addition to the previously mentioned three aspects to consider the systems synchronized. Figure 3.6.3-8 Different states of the system 1.1.1.12 M EASURED INPUT VALUES Analog voltage measurement values are used for the function block.
Page 393 Application Guide - NP900 Series 393 (504 1.1.1.13 F UNCTION BLOCKING In the blocking element the block signal is checked in the beginning of each program cycle. Blocking signal is received from the blocking matrix for the function dedicated input.
Page 394 Application Guide - NP900 Series 394 (504 Name Range Step Default Description SYN U conditions LL only LL only Allowed states of the supervised systems. LL & LD LL & DL LL & DD LL & LD & DL LL & LD & DD LL &...
Page 395 Application Guide - NP900 Series 395 (504 Table 1.1.1.15-244 Event codes of the synchrocheck function instance 1 – 3. Event Event Event Event Alarm Number channel Event block name Code Description Type Type 2880 45 SYN1 0 SYN1 Blocked On...
Page 396: Auto-Reclosing 0  1 (79)
Application Guide - NP900 Series 396 (504 3.6.4 A 0  1 (79) RECLOSING Autoreclosing (AR) means coordinated de-energisation and energisation of transmission or distribution overhead-line with purpose to clear permanent or semi-permanent cause of fault from the line in order to restore supply automatically to the line.
Page 397 Application Guide - NP900 Series 397 (504 the line is not-energized) and the supply is restored to the line. If the fault is not cleared by this first autoreclosing cycle (called Shot) then more shots can be applied to the line.
Page 398 Application Guide - NP900 Series 398 (504 3.6.4.2 A UTORECLOSING SCHEME IN RADIAL NETWORK In typical medium voltage overhead network construction is radial type and does not cause any additional requirements for the autoreclosing scheme in addition to the mentioned air de-ionization time and the capacity of the circuit breaker which should be the dictating magnitudes for the autoreclosing scheme.
Page 399 Application Guide - NP900 Series 399 (504 Figure 3.6.4.2-183. Autoreclosing shot settings, two requests and two shots are initialized. In this example for earth faults its own operating time settings are used and for overcurrent time delay its set from autorecloser. Both fault types can initialize both of the shots with different settings.
Page 400 Application Guide - NP900 Series 400 (504 3.6.4.3 A UTORECLOSING SEQUENCE FROM RIP WITH TWO SHOT FAILURE For this earth fault autoreclosing scheme directional earth fault protection Trip signal to operate was set as REQ2 starter which was enabled to Shot1 and Shot2 with following settings.
Page 401 Application Guide - NP900 Series 401 (504 1. Earth fault is found in the protected line which causes directional earth fault protection I0Dir> to start and calculate the operating time for the trip. 2. I0Dir> trips and gives open command to the breaker open coil. Autoreclosing REQ2 is initiated and AR running, AR2 Requested and Shot1 Running signals are activated.
Page 402 Application Guide - NP900 Series 402 (504 3.6.4.4 A UTORECLOSING SEQUENCE FROM RIP WITH TWO SHOT HIGH SPEED FAILS AND TIME DELAYED SUCCEEDS The Scheme for autoreclosing starter and shots is the same than in the previous example with same settings and signals. In this example fault persist for the high speed autoreclosing but is cleared by time delayed autoreclosing.
Page 403 Application Guide - NP900 Series 403 (504 1. Earth fault is found in the protected line which causes directional earth fault protection I0Dir> to start and calculate the operating time for the trip. 2. I0Dir> trips and gives open command to the breaker open coil. Autoreclosing REQ2 is initiated and AR running, AR2 Requested and Shot1 Running signals are activated.
Page 404 Application Guide - NP900 Series 404 (504 11. Autoreclosing Reclaim Time is exceeded and Autorecloser is set to Ready state waiting for next request. 3.6.4.5 A UTORECLOSING SEQUENCE FROM RIP WITH TWO SHOT HIGH SPEED SUCCEEDS The Scheme for autoreclosing starter and shots is the same than in the previous examples with same settings and signals.
Page 405 Application Guide - NP900 Series 405 (504 Figure 3.6.4.5-189 Signal status graph of the transient earth fault autoreclosing cycle. 1. Earth fault is found in the protected line which causes directional earth fault protection I0Dir> to start and calculate the operating time for the trip.
Page 406 Application Guide - NP900 Series 406 (504 specific reclaim times is that if fault is returning in shot specific reclaim time autorecloser jumps to next shot. If a fault return after successful cycle and Autoreclosing reclaim time is running recloser will go directly to final trip state and lock-out state.
Page 407 Application Guide - NP900 Series 407 (504 Figure 3.6.4.6-191 Signal status graph of the permanent overcurrent autoreclosing cycle. 1. Overcurrent is found in the protected line which causes overcurrent protection I> to pick up and activate REQ1 which causes the starting time calculating for the Shot 1.
Page 408 Application Guide - NP900 Series 408 (504 8. Shot2 Dead time calculation is finished and the recloser sends close command to the breaker. 9. Dead Time for Shot2 is exceeded and autorecloser sends close request for the Object breaker, the close conditions are met and the breaker close command is sent to breaker close coil.
Page 409 Application Guide - NP900 Series 409 (504 Figure 3.6.4.7-193 Signal status graph of the semi-permanent overcurrent autoreclosing cycle. 1. Overcurrent is found in the protected line which causes overcurrent protection I> to pick up and activate REQ1 which causes the starting time calculating for the Shot 1.
Page 410 Application Guide - NP900 Series 410 (504 closed indication is received and the autorecloser starts to calculate Reclaim time for Shot1 simultaneously with the arcing time. 6. Arcing time for the Shot1 is exceeded which means that the fault is not cleared and the recloser sends open command to the breaker.
Page 411 Application Guide - NP900 Series 411 (504 This type of sequence represents 75-85% of all the faults in the medium voltage overhead line network. Figure 3.6.4.8-195 Signal status graph of the transient overcurrent autoreclosing cycle. 1. Overcurrent is found in the protected line which causes overcurrent protection I> to pick up and activate REQ1 which causes the starting time calculating for the Shot 1.
Page 412 Application Guide - NP900 Series 412 (504 5. Circuit breaker is closed and since fault cleared by the Shot1 given non-energized time, no pick-ups are detected. Close command is drop off after the breaker closed indication is received and the autorecloser starts to calculate Reclaim time for Shot1.
Page 413 Application Guide - NP900 Series 413 (504 Figure 3.6.4.9-196 Autoreclosing with distributed generation in the line. For this operation there needs to be communication link in between of the substation master relay and 20 kV collector station incomer follower relay. When autoreclosing is initiated the collector station breaker is opened until the autoreclosing cycle is completed.
Page 414 Application Guide - NP900 Series 414 (504 Arcing time can be used for controlling the autoreclosing in cases protection function Start signal is making the requests. In case if the request (start) activates during the Reclaim time the Arcing time calculation starts and if fault persists autorecloser shall continue to next stage.
Page 415 Application Guide - NP900 Series 415 (504 several operational event signals. Time stamp resolution is 1ms. Function provides also cumulative counters for each applied reclosing events and requests. Autorecloser function can be divided into starter, shot selector state machine, sorter and shot blocks which operate dynamically during the reclosing cycles based into the given settings and input signals monitoring.
Page 416 Application Guide - NP900 Series 416 (504 In addition to the previously mentioned also manual control of the breaker whether open or close during the autoreclosing cycle will always cause reset of autorecloser. For example if the breaker is closed manually during the Dead Time autorecloser will enter to general reclaim mode and if the breaker is closed towards fault it will cause lock-out of autorecloser function.
Page 417 Application Guide - NP900 Series 417 (504 Table 3.6.4.12-245 AR input signals. Signal Range Description Any binary Input for dynamically block the autoreclosing. When input is activated spontaneous signal in the the recloser will halt its operation and refuses any further requests.
Page 418 Application Guide - NP900 Series 418 (504 AR3 Request On When autorecloser is executing shot requested by AR3 priority this signal is activated. Signal can be connected to any relay IO as well as into communication protocols. AR4 Request On When autorecloser is executing shot requested by AR4 priority this signal is activated.
Page 419 Application Guide - NP900 Series 419 (504 Table 3.6.4.14-247 Autorecloser basic settings. Setting Range Description AR Mode 0: Disabled Selection of the Autorecloser Enabled / Disabled in 1: Enabled the configuration. Default value is Disabled. AR Object 0: Object 1 Selection of the monitored / controlled breaker object.
Page 420 Application Guide - NP900 Series 420 (504 Table 3.6.4.14-248 Autorecloser shot settings. Setting Range Description AR1,2,3,4,5 Shot 0: Disabled Shotx selection enabled / disabled for request ARx. If 1,2,3,4,5 1: Enabled disabled ARx request will skip Shot 1 and seek for next enabled shot.
Page 421 Application Guide - NP900 Series 421 (504 Figure 3.6.4.14-198 Autorecloser shot setting parameters. Autorecloser shot settings are grouped into corresponding rows where setting of each shot is straightforward. From the settings can be seen how the reclosing cycle is executed by each request row by row and which functions initiate requests and which shots and requests are in use.
Page 422 Application Guide - NP900 Series 422 (504 3.6.4.15 I NHIBIT AND OCKED STATES OF AUTORECLOSER FUNCTION Autorecloser has several locked and inhibit states where reclosing for some given reason cannot be allowed. When autorecloser function enters into the not ready state it will give indication of the reason it cannot be in ready state in order to quickly rectify what is causing the problem of the functions operation.
Page 423 Application Guide - NP900 Series 423 (504 3.6.4.16 D ISPLAYING AUTO RECLOSER TIMERS IN MIMIC VIEW It is possible to enable timers to display in mimic view. The timer will display the reclaim AR timer time and dead time delay. To do this load the aqs file of the relay and enable value Tools ...
Page 424 Application Guide - NP900 Series 424 (504 Table 3.6.4.17-249. Event codes of the AR function. Event Event Event Number channel Event block name Code Description 4032 63 AR1 0 AR Ready On 4033 63 AR1 1 AR Ready Off 4034...
Page 425 Application Guide - NP900 Series 425 (504 4072 63 AR1 40 Shot 4 Execute Off 4073 63 AR1 41 Shot 5 Execute On 4074 63 AR1 42 Shot 5 Execute Off 4075 63 AR1 43 Seq Finished Final Trip Armed...
Page 426 Application Guide - NP900 Series 426 (504 dd.mm.yyyy hh:mm:ss.mss 1664 NEF1 Start ON dd.mm.yyyy hh:mm:ss.mss 1666 NEF1 Trip ON dd.mm.yyyy hh:mm:ss.mss 4065 AR1 Shot 1 Execute On dd.mm.yyyy hh:mm:ss.mss 4037 AR1 AR Reclosing request On dd.mm.yyyy hh:mm:ss.mss 4053 AR1 AR2 Request On dd.mm.yyyy hh:mm:ss.mss...
Page 427: Cold Load Pick-Up (Clpu) (68)
Application Guide - NP900 Series 427 (504 Shot 3 started Shot 4 started Shot 5 started Shot 1 requested by AR1 Shot 2 requested by AR1 Shot 3 requested by AR1 Shot 4 requested by AR1 Shot 5 requested by AR1...
Page 428 Application Guide - NP900 Series 428 (504 possible that in some areas of the industrial network CLPU functionality may be useful also. CLPU function measures constantly phase current magnitudes and magnitude changes which on the operating decisions are based. Blocking signal and setting group selection controls the operating characteristics of the function during normal operation.
Page 429 Application Guide - NP900 Series 429 (504 3.6.5.1 M EASURED INPUT VALUES Function block uses analog current measurement values. Function block always utilizes peak-to-peak measurement from samples and by user selection the monitored magnitude can be either fundamental frequency RMS values, True RMS values from the whole harmonic specter of 32 components or peak to peak values.
Page 430 Application Guide - NP900 Series 430 (504 The pick-up activation of the function is not directly equal to start-signal generation of the function. Start signal is allowed if blocking condition is not active. 3.6.5.3 F UNCTION BLOCKING In the blocking element the block signal is checked in the beginning of each program cycle.
Page 431 Application Guide - NP900 Series 431 (504 Table 3.6.5.4-253 Operating time characteristics setting parameters. Name Range Step Default Description Tset 0.000…1800.000s 0.005s 10.000s CLPU start timer, this setting defines how long the ILow condition has to last before CLPU is activated.
Page 432 Application Guide - NP900 Series 432 (504 Figure 3.6.5.4-201 Example of timers and pick-up parameters. No CLPU pick up since too short current low situation. ILow Tset CLPU does not activate even current has been under . The time setting...
Page 433 Application Guide - NP900 Series 433 (504 Figure 3.6.5.4-203 Example of timers and pick-up parameters. Activated CLPU instant release due to too long starting. ILow Tset . CLPU activates after current has been under setting for time When current IHigh...
Page 434 Application Guide - NP900 Series 434 (504 Figure 3.6.5.4-205 Example of timers and pick-up parameters. Inrush current is detected during Tmin time. ILow Tset. CLPU activates after current has been under setting for time When current ILow IHigh Tmin exceed the...
Page 435 Application Guide - NP900 Series 435 (504 Table 3.6.5.5-254. Event codes of the CLPU function instances 1 – 4. Event Event Event Event Number channel Event block name Code Description Type 2688 42 CLP1 0 LowStart ON 2689 42 CLP1...
Page 436: Switch On To Fault (Sotf)
Application Guide - NP900 Series 436 (504 3.6.6 S (SOTF) WITCH ON TO FAULT Switch on to fault (SOTF) function is used for speeding up the tripping in case if the breaker is closed towards a fault or forgotten earthing in order to reduce the damage in the fault- or problem location.
Page 437 Application Guide - NP900 Series 437 (504 Table 3.6.6.1-256 Signal inputs used by the SOTF function. Input Description SOTF activate Binary input for the function to arm and start calculate the SOTF time. Any binary input signal can be used to activate SOTF and start the calculation. Start of the function is applied from rising edge of the signal.
Page 438: Voltage Regulator (90)
Application Guide - NP900 Series 438 (504 In the register of the SOTF function is recorded activated “On” event process data. In the table below is presented the structure of SOTF function register content. This information is available in 12 last recorded events for all provided instances separately.
Page 439 Application Guide - NP900 Series 439 (504 3.6.7.1 AVR FEATURES AND CONFIGURATION AVR features separate definite and inverse operating time voltage raise and lower windows, instant overvoltage lower, undervoltage blocking and inbuilt overcurrent blocking functions. Target voltage as well as operating settings for the voltage windows can be changed via setting group changes.
Page 440 Application Guide - NP900 Series 440 (504 Figure 3.6.7.1-207 Two of the voltage measurement connection options. If the relay has full voltage connection with complete phase to phase or phase to ground voltages (left side connection example 3LN+U4 (also 3LL + U4 and 2LL+U3+U4 modes) AVR measurement voltage can be selected directly to U12, U23 or U31.
Page 441 Application Guide - NP900 Series 441 (504 Figure -208 Connection of mA input to option card. Either of the channel 1 or 2 can 3.6.7.1 be used. General settings menu includes also on-line measurements and calculations from the AVR function as well as the location of the tap changer at the moment. Information about the settings and AVR status is found in this part.
Page 442 Application Guide - NP900 Series 442 (504 Figure 3.6.7.1-209 Control pulse timing settings. Control pulses minimum and maximum times are user set. If during the control pulse tap changes and the voltage changes as well to controlled direction the command is terminated.
Page 443 Application Guide - NP900 Series 443 (504 Tap changer properties are set to the AVR: Setting Value Tap position indication mA input Tap steps totally 18 steps Tap center position 9 step Tap step effect 1.67 % mA input low range...
Page 444 Application Guide - NP900 Series 444 (504 Minimum voltage window size can be calculated as follows: U >/< = 1.2 × tap step effect % window This gives 20% more of total band for regulating and with this setting is made sure that the voltage is inside the voltage window after tap change operation.
Page 445 Application Guide - NP900 Series 445 (504 Figure 3.6.7.1-211 Set window is still too tight in comparison to the tap effect. Voltage regulator reaches the set target window with one tap change. However the voltage after tap change is very near to opposite limit. If voltage changes back to original value tap change is needed again.
Page 446 Application Guide - NP900 Series 446 (504 Figure 3.6.7.1-212 Setting recommendation. Set window is 20% bigger than tap step effect. This sensitivity is recommended for stabile and calm operation. This ensures that after tap changing the voltage is not too near of the opposite voltage window border. If more sensitivity is wanted, voltage window below 5% bigger than tap step effect is not recommended.
Page 447 Application Guide - NP900 Series 447 (504 Figure 3.6.7.1-213 First voltage window is 20% bigger than tap step effect. Second window is increased by two tap steps from the first window. Operating time for the second fast window (U ≫/<<...
Page 448 Application Guide - NP900 Series 448 (504 (U ≫/<< window Figure 3.6.7.1-214 Inverse operating time characteristics for second Inverse operating time controls voltage back to the set target window faster if the deviation is bigger and slower when deviation is smaller.
Page 449 Application Guide - NP900 Series 449 (504 Figure 3.6.7.1-215 Combined operating time characteristics of voltage windows in function of voltage deviation to the set target voltage. From the operating characteristics it can be seen that the faster inverse operation until the U>>/<<...
Page 450 Application Guide - NP900 Series 450 (504 For very high overvoltage AVR has an instant low function which lowers the voltage without any given set time delay except the given minimum time between control pulses. This function is used in the AVR until the measured voltage is below the set instant low threshold level.
Page 451 Application Guide - NP900 Series 451 (504 Figure 3.6.7.1-217 Instant low setting effect to time characteristics. AVRs low voltage blocking prevents the operation of the tap changer control in case of heavy short circuit faults in the feeding network side as well as the drifting of the tap to maximum voltage increase position during power off situations.
Page 452 Application Guide - NP900 Series 452 (504 Figure 3.6.7.1-218 Low voltage blocking prevents the tap changer operations to avoid the control to maximum position when the feeding voltage returns to nominal level. Setting suggestion for the low voltage blocking is the maximum tap increase positions effect.
Page 453 Application Guide - NP900 Series 453 (504 3.6.7.2 M EASURED INPUT VALUES AVR measures phase to phase voltages for voltage controlling. Optionally phase currents can be measured for overcurrent blocking. Table 3.6.7.2-259 Measurement magnitudes used by the AVR function. Signal...
Page 454 Application Guide - NP900 Series 454 (504 6b: I> block on 7b: Tap on highlimit 8b: Tap on lowlimit 9b: Operation blocked 10b: U>/< pick-up on 11b: U>>/<< pick-up on 12b: Control wait time on 13b: Manual control mode on...
Page 455 Application Guide - NP900 Series 455 (504 tap changer in relation to whole range 0…max tap steps. Tap changer on high Indication if the tap 0:No 0:No border changer has 1:Yes reached maximum voltage high position Tap changer on low...
Page 456 Application Guide - NP900 Series 456 (504 3.6.7.5 T AP SETTINGS In tap settings the tap changer equipment properties and connection for position indication to AVR are set. Table 3.6.7.5-263 Tap settings parameters. Name Description Range Step Default Tap position indication...
Page 457 Application Guide - NP900 Series 457 (504 3.6.7.6 S TATISTICS Counters of the AVR common operations and statuses Table 3.6.7.6-265 Counters of AVR function Name Description Range Step Default AVR rised voltage How many times One tap control operation AVR has increased...
Page 458 Application Guide - NP900 Series 458 (504 in use) voltage window threshold deviation (up/down) before regulating command U>>/<< window in use High set 0:Not in use 0:Not in use definite/inverse 1:In use time voltage window in use or U>> setting (+UTGT) High voltage limit 0.10…30.00%...
Page 459 Application Guide - NP900 Series 459 (504 contacts (for application use) while the second one blocks only the output contacts but control algorithm is still operational (for commissioning the settings). Table 3.6.7.8-267 AVR block inputs Name Description AVR Block op and outs Application block for the AVR function.
Page 460 Application Guide - NP900 Series 460 (504 Table 3.6.7.10-269. Event codes of the AVR function. Event Event Event Event Alarm Number channel Event block name Code Description Type Type 7360 115 VRG1 0 Tap Raise command On 7361 115 VRG1...
Page 461: Monitoring Functions
Application Guide - NP900 Series 461 (504 3.7 M ONITORING FUNCTIONS 3.7.1 C (CTS) URRENT TRANSFORMER SUPERVISION Current transformer supervision (CTS) function is meant to be used for monitoring the CT:s, wirings in between of the IED and IED CT inputs in case of malfunction or wire breaks.
Page 462 Application Guide - NP900 Series 462 (504 from each of the two output signal. Time stamp resolution is 1ms. Function provides also cumulative counters for CTS alarm and BLOCKED events. In the following figure is presented the simplified function block diagram of the CTS function.
Page 463 Application Guide - NP900 Series 463 (504 Table 3.7.1.1-271 Analogic magnitudes used by the CTS function. Signal Description Time base IL1RMS Fundamental RMS measurement of phase L1/A current 5 ms IL2RMS Fundamental RMS measurement of phase L2/B current 5 ms...
Page 464 Application Guide - NP900 Series 464 (504 Table 3.7.1.2-273 Pick-up characteristics setting Name Range Step Default Description Iset Highlimit 0.01 … 40.00 x In 0.01 x In 1.20 x In Pick-up threshold for phase current measurement. This setting limit defines the upper limit for the phase current pick-up element.
Page 465 Application Guide - NP900 Series 465 (504 Blocking signal can be tested also in the commissioning phase of the stage by software switch signal when relay common and global testing mode is activated. User settable variables are binary signals from the system. Blocking signal needs to reach the IED minimum of 5 ms before the set operating delay has passed for blocking to be active in time.
Page 466 Application Guide - NP900 Series 466 (504 Figure 3.7.1.5-221 System in case when secondary circuit fault is found in phase L1 wiring. When fault is detected and all of the conditions are met the CTS timer will start counting. If the situation continues until the set time has been spent CTS will issue alarm.
Page 467 Application Guide - NP900 Series 467 (504 Figure 3.7.1.5-223 System in case when there is no wiring fault and heavy unbalance. If any of the phases is over the Iset Highlimit the operation of the CTS is not activated. This behavior is applied in short circuit and earth faults also if the fault current exceeds the Iset high setting.
Page 468 Application Guide - NP900 Series 468 (504 Figure 3.7.1.5-225 System in normal situation when measuring also the residual current. When the residual condition is added the sum current and residual current are compared against each other and the wiring condition can be verified.
Page 469 Application Guide - NP900 Series 469 (504 Figure 3.7.1.5-227 System in case when primary phase current wiring is broken. In this case all other conditions are met except the residual difference which is now 0 x In and thus indicate primary side fault.
Page 470 Application Guide - NP900 Series 470 (504 3.7.1.6 E VENTS AND REGISTERS The CTS function generates events and registers from the status changes of the ALARM activated and blocked signals. To main event buffer is possible to select status “On” or “Off”...
Page 471: Fuse Failure (Vts) (60)
Application Guide - NP900 Series 471 (504 3.7.2 F (VTS) (60) USE FAILURE Voltage transformer supervision is used to detect errors in the secondary circuit of the voltage transformer. This signal is mostly used as alarming function or to disable functions that require adequate voltage measurement.
Page 472 Application Guide - NP900 Series 472 (504 Table 3.7.2.2-277 Pick-up characteristics setting Name Range Step Default Description Voltage low 0.00 … 0.50 x Un 0.01 x Un 0.05 x Un If at least one of the measured voltages are pickup...
Page 473 Application Guide - NP900 Series 473 (504 From blocking of the function a HMI display event as well as time stamped blocking event with information of the startup current values and fault type is issued. Blocking signal can be tested also in the commissioning phase of the stage by software switch signal when relay common and global testing mode is activated.
Page 474: Disturbance Recorder (Dr)
Application Guide - NP900 Series 474 (504 Table 3.7.2.5-279. Register content. Date & Time Event Volt 1,2,3 status System status Input Trip time Used code A,B,C remaining angle diff dd.mm.yyyy 3392- 0b=No Voltage; 0=BusDead; 1 - 8 hh:mm:ss.mss 3403 1b=Voltage Ok;...
Page 475 Application Guide - NP900 Series 475 (504 Table 3.7.3.1-280 Analogue recording channels can be chosen between channels represented in table below. Signal Description Sample rate Phase current I 8/16/32/64 s/c Phase current I 8/16/32/64 s/c Phase current I 8/16/32/64 s/c...
Page 476 Application Guide - NP900 Series 476 (504 Sec.Res.curr.I02 Pri.calc.I0 Sec. calc.I0 pu.calc.I0 calc.I0 Pha.angle Pha.curr.IL1 TRMS Pha.curr.IL2 TRMS Pha.curr.IL3 TRMS Pha.curr.IL1 TRMS Sec Pha.curr.IL2 TRMS Sec Pha.curr.IL3 TRMS Sec Pha.curr.IL1 TRMS Pri Pha.curr.IL2 TRMS Pri Pha.curr.IL3 TRMS Pri pu.Pos.seq.curr. pu.Neg.seq.curr.
Page 477 Application Guide - NP900 Series 477 (504 P-P curr.I02 U1Volt p.u. U1Volt pri U1Volt sec U2Volt p.u. U2Volt pri U2Volt sec U3Volt p.u. U3Volt pri U3Volt sec U4Volt p.u. U4Volt pri U4Volt sec U1Volt TRMS p.u. U1Volt TRMS pri U1Volt TRMS sec U2Volt TRMS p.u.
Page 478 Application Guide - NP900 Series 478 (504 System volt UL31 ang System volt UL1 mag System volt UL1 ang System volt UL2 mag System volt UL2 ang System volt UL3mag System volt UL3 ang System volt U0 mag System volt U0 ang...
Page 479 Application Guide - NP900 Series 479 (504 Object1…5 Open Request Object1…5 Close Request Object1…5 Not ready wait Object1…5 No sync wait Object1…5 Not ready fail Object1…5 No sync fail Object1…5 Open timeout Object1…5 Close timeout AR1…5 Request on AR Running AR Shot 1…5 Running...
Page 480 Application Guide - NP900 Series 480 (504 Table 3.7.3.2-282 Disturbance recorder setting table is presented below. Name Range Step Default Description Manual Trigger 0:Disabled Trig the disturbance recorder manually. 1:Trig Clear all records 0:Disabled Clears all disturbance recordings. 1:Clear Clear newest record 0:Mega Clears the latest of stored recordings.
Page 481 Application Guide - NP900 Series 481 (504 3.7.3.4 A PPLICATION EXAMPLE In this chapter is presented an application example of setting and analyzing the disturbance recorder. Configuration is done by using “SMART9” –configuration and setting tool and “SMARTviewer” is used for analyzing the recording.
Page 482 Application Guide - NP900 Series 482 (504 Figure 3.7.3.4-229 Disturbance recorder settings. When there is at least one recording in the memory of the IED the recording can be analyzed by using SMARTviewer software. First the recording has to be read from the memory of the IED by selecting Disturbance Recorder ...
Page 483 Application Guide - NP900 Series 483 (504 Where: fn is nominal frequency • AnCh is the amount of recorded analog channels (which is then summed with 1 • which stand for time stamp for each recorded sample) SR is the sample rate chosen by parameter (8,16,32 or 64 samples per cycle) •...
Page 484 Application Guide - NP900 Series 484 (504 Figure 3.7.3.6-231 Add signals to plotters. 1. As a default the default plotter is empty. Choose measured signals on the left to move them to the plotter. In this example phase currents IL1, IL2 and IL3 are selected.
Page 485 Application Guide - NP900 Series 485 (504 Figure 3.7.3.6-283 Zooming and using SMARTviewer generally. 1. To remove plotters one at the time use red minus key icon “1” that can be found on top. Note, “Remove Plotter” -text appears when moving mouse on top of the icon.
Page 486: Measurement Recorder
Application Guide - NP900 Series 486 (504 3.7.4 M EASUREMENT RECORDER Specific measurements can be recorded on a file by using the measurement recorder. In the measurement recorder-dialog, the desired measurements to be recorded can be selected by checking the checkboxes. A connection to a relay must be established via SMART9-software and live edit mode must be enabled, for the measurement recorder to be able to activate.
Page 487: Circuit Breaker Wear -Monitor (Cbw)
Application Guide - NP900 Series 487 (504 3.7.5 C (CBW) IRCUIT BREAKER WEAR MONITOR Circuit breaker wear (CBW) function is used for monitoring the circuit breaker lifetime before maintenance needs due to interrupting currents and mechanical wearing. CBW function uses the circuit breaker manufacturer given data for the breaker operating cycles in relation to the current breaker has operated.
Page 488 Application Guide - NP900 Series 488 (504 1ms. Function provides also cumulative counters for Open operations, Alarm 1 and Alarm 2 events. Operations left for each phase can be monitored also in the function. In the following figure is presented the simplified function block diagram of the CBW function.
Page 489 Application Guide - NP900 Series 489 (504 Table 3.7.5.2-285 Circuit breaker characteristics settings. Name Range Step Default Description Current 1 0.00…100.00 kA 0.01 kA 1.00 kA Nominal operating current of the breaker (Inom) (rms) Operations 0… 200000 Op 1 Op...
Page 490 Application Guide - NP900 Series 490 (504 Table 3.7.5.5-287. Event codes of the CBW function instance Event Event Event Event Number channel Event block name Code Description Type 3713 58 CBW1 1 CBWEAR1 Triggered 3714 58 CBW1 2 CBWEAR1 Alarm1 On...
Page 491 Application Guide - NP900 Series 491 (504 3.7.5.6 S ETTING EXAMPLE A996A...
Page 492: Total Harmonic Distortion Monitor (Thd)
Application Guide - NP900 Series 492 (504 Set the CBW stage as follows: Parameter Value Current 1 (Inom) 0.80 kA Operation 1 (Inom) 30000 Op Current 2 (Imax) 16.00 kA Operations 2 (Imax) 100 Op Enable Alarm 1 1: Enabled...
Page 493 Application Guide - NP900 Series 493 (504 Power THD ratio is the sum of harmonic components squared divided by the fundamental component squared. … I , where I = measured current, x= measurement input, n = harmonic number Amplitude THD (percentage) is otherwise similar in difference of that the result is square root of the Power THD: …...
Page 494 Application Guide - NP900 Series 494 (504 Figure 3.7.6-234 Simplified function block diagram of the THD function. 3.7.6.1 M EASURED INPUT VALUES Function block uses analog current measurement values. Function block always utilizes FFT measurement of whole harmonic specter of 32 components from each measured current channel which from the THD is calculated either as amplitude or power ratio THD.
Page 495 Application Guide - NP900 Series 495 (504 function and is always related to the setting value. The setting value is common for all measured phases and single-, dual- or all phases Im exceed of the Iset value will cause pick-up operation of the function.
Page 496 Application Guide - NP900 Series 496 (504 User settable variables are binary signals from the system. Blocking signal needs to reach the IED minimum of 5 ms before the set operating delay has passed for blocking to be active in time.
Page 497 Application Guide - NP900 Series 497 (504 Table 3.7.6.5-292. Event codes of the THD function Event Event Event Event Number channel Event block name Code Description Type 3521 55 THD1 1 THD Start Phase On 3522 55 THD1 2 THD Start Phase Off...
Page 498: Alarm
Application Guide - NP900 Series 498 (504 3.7.7 A LARM Signal alarming is a feature included in NPS914 alarming units. Alarming unit has 64 user settable alarms. Each alarm has a user defined description and an activation signal. Alarm settings Control ...
Page 499 Application Guide - NP900 Series 499 (504 Figure 3.7.7.2-11 Digital inputs assigned as alarm activating signals. Assign digital inputs or logical outputs into alarms by clicking on the matrix. When the matrix is done it must be sent to the relay for the changes to take effect (Commands ...
Page 500: Fault Locator (21Fl)
Application Guide - NP900 Series 500 (504 After this is done in the logic editor click Export and then update logic (Commands  Write to relay  Logic  Write). 3.7.7.4 LEARING LATCHED SIGNALS If latched signals are connected to alarms the relay requires the user to push the back button in the relays front port before it can be cleared.
Page 501 Application Guide - NP900 Series 501 (504 Table 3.7.8.1-295 Measurement magnitudes used by the FLX function Signals Description Time base L-N voltages of first voltage transformer VT1 U1,U2,U3 5 ms CT1 IL1,IL2,IL3 Measurement of phase L1/A, L2/B & L3/B 5 ms current 3.7.8.2 F...
Page 502 Application Guide - NP900 Series 502 (504 Table 3.7.8.2-297 Current conditions needed to trig impedance recording. P-E voltages available P-E Voltage not available Currents over limit Recorded impedance Recorded impedance IL1,IL2,IL3 XL12 XL12 IL1,IL2 XL12 XL12 IL2,IL3 XL23 XL23 IL1,IL3...
Page 503 Application Guide - NP900 Series 503 (504 Table 3.7.8.4-298. Event codes of the FLX function. In the table below is presented the structure of FLX function register content. This information is available in 12 last recorded events. Table 3.7.8.4-299. Register content.
Page 504 Application Guide - NP900 Series 504 (504 A996A...