Application Example - Siemens 6MD85 Manual

Protection and Automation Functions
7.22 Power Protection (P,Q), 3-Phase
[dw_tilt-power reactive power, 2, en_US]
Figure 7-174
Pickup
The stage compares the selected power value with the set Threshold. Depending on the stage type (Power
Q> or Power Q<) being above or falling below the threshold value will lead to a pickup.
Dropout Delay
A delay can be set for the dropout when the measured value falls below the dropout threshold. The pickup is
maintained for the specified time. The time delay of the tripping (parameter Operate delay) continues to
run. Once the Operate delay has elapsed, the stage trips.
Blocking the Stage
In the event of blocking, the picked up stage will be reset. Blocking the stage is possible externally or internally
via the binary input signal

Application Example

7.22.5
The setting of the function will be explained using an active/reactive power range as an example. If the appa-
rent power phasor is within the power range (in
alarm indication is generated. For this purpose, you have to make an AND operation of the stage indications of
the active and reactive power stage in CFC. The function used is 3-phase power measurement.
shows the threshold values and the location of the characteristics in the PQ diagram.
856
Tilt-Power Characteristic
>Block stage .
Figure 7-175 tripping zone defined by characteristics), an
SIPROTEC 5, High-Voltage Bay Controller, Manual
C53000-G5040-C015-9, Edition 11.2017
Figure 7-175