Reactive power overload feature
GUID-6DA88E90-366A-494F-B3A4-F8B5A3FD6396 v3
Note that during testing the reactive power overload feature the harmonic voltage
overload feature or overcurrent feature may also give pickup and trip signals depending
on their actual settings. Therefore it is recommended to switch them off during this test.
1. Inject current equal to the set reactive power overload pickup level under setting parameter
UP_QOL (that is, 1.3 · 0.587A = 0.763A at 50Hz for this SCB) in phase A only.
2. Check that function binary output signals PU_QOL_A and PU_QOL are set to one.
3. Check that function binary output signals TRQOL and TRIP are set to one after the set time under
parameter tQOL (for example, 60s for this SCB) has expired.
4. If any of these signals are used for tripping, signaling and/or local/remote indication check that all
relevant contacts and LEDs have operated and that all relevant GOOSE messages have been
sent.
5. Check that service value from the function for current in phase A, on the local HMI under Main
menu /Test is approximately 382A (that is, 0.763A · (500/1) = 382A).
6. Check that service value from the function for reactive power in phase A, on the local HMI under
Main menu /Test is approximately 169% (that is, 1.3 · 1.3 = 1,69pu = 169%).
7. Stop injection of all currents (that is, set all currents back to 0A).
8. Check that all above mentioned function binary output signals now have logical value zero.
9. Repeat above steps 1 - 8 for phase B and phase C.
Note that operation of this feature is based on injected current and internally calculated
true RMS values. That means that this feature is also able to trip for current signals with
varying frequency. However due to relatively complex calculation procedure it is
recommended to do secondary tests only with fundamental frequency current signals.
The following formula can be used to calculate SCB reactive power in per-unit system when current with
different frequency from the rated frequency is injected.
[ ] [ ]
2
rated
injected
f
Q pu I pu
f
= ×
EQUATION2273 V1 EN-US (Equation 93)
Harmonic voltage overload feature
GUID-3C6B2C73-026D-4173-BD4D-1E7E9ADAE160 v3
Note that during testing the harmonic voltage overload feature the reactive power
overload feature or overcurrent feature may also give pickup and trip signals depending
on their actual settings. Therefore it is recommended to switch them off during this test.
Procedure to test inverse time delayed step:
The following points on the inverse curve are defined per relevant IEC/ANSI standards for time multiplier
value set to k_HOL_IDMT=1.0
UpeakRMS [pu]
1.15 1.2 1.3 1.4 1.7 2.0 2.2
Time [s] 1800 300 60 15 1 0.3 0.12
Section 11 1MRK 504 165-UUS Rev. J
Testing functionality by secondary injection
194 Transformer protection RET670
Commissioning manual
© 2017 - 2021 Hitachi Power Grids. All rights reserved
To Next Page
Loading...
