Application - ABB RELION REC615 Technical Manual

1MRS758755 C
5.4.4.5 Recorded data
All the information required for a later fault analysis is recorded to SCEFRFLO
recorded data. In the protection relay, recorded data is found in Monitoring >
Recorded data > Other protection > SCEFRFLO.
The function has also monitored data values which are used for the read-out of
continuous calculation values.
are available as continuous monitoring values during a fault.
Table 538: Cross reference table for recorded and monitored data values
Recorded data
Flt loop
Flt distance
Flt Dist quality
Flt loop resistance
Flt loop reactance
Flt phase reactance
Flt point resistance
Flt to Lod Cur ratio
Equivalent load Dis
XC0F Calc
5.4.4.6 Measurement modes
The full operation of SCEFRFLO requires that all three phase-to-earth voltages are
measured. The voltages can be measured with conventional voltage transformers or
voltage dividers connected between the phase and earth (
"Wye"). Another alternative is to measure phase-to-phase voltages (
is set to "Delta") and residual voltage (Uo). Both alternatives are covered by setting
the configuration parameter
When the
phase-to-phase voltages are available (but not Uo), only short-circuit measuring
loops (fault loops "AB Fault", "BC Fault" or "CA Fault" or "ABC Fault") can be
measured accurately. In this case, the earth-fault loops (fault loops either "AG Fault",
"BG Fault" or "CG Fault") cannot provide correct fault distance estimates and the
triggering of the function in case of earth fault is automatically disabled.
5.4.5

Application

The main objective of the feeder terminals is a fast, selective and reliable operation
in faults inside the protected feeder. In addition, information on the distance to
the fault point is very important for those involved in operation and maintenance.
Reliable information on the fault location greatly decreases the downtime of the
protected feeders and increases the total availability of a power system.
SCEFRFLO provides impedance-based fault location. It is designed for radially
operated distribution systems and is applicable for locating short circuits in all
kinds of distribution networks. Earth faults can be located in effectively earthed
and low resistance/low-reactance earthed networks. Under certain limitations,
REC615 & RER615
Technical Manual
Table 538
Phase voltage Meas to "Accurate".
Phase voltage Meas setting is set to "Ph-to-ph without Uo" and only
Protection related functions
shows which of the recorded data values
Monitored data
FAULT_LOOP
FLT_DISTANCE
FLT_DIST_Q
RFLOOP
XFLOOP
XFPHASE
RF
IFLT_PER_ILD
S_CALC
XC0F_CALC
VT connection is set to
VT connection
515