Table of Contents
Advertisement
Section 10
Testing functionality by secondary injection
Harmonic voltage overload feature
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 kHOLIDMT=1.0
UpeakRMS [pu]
Time [s]
Here will be shown how to test the fourth point from the above table. Other points can be tested in
the similar way:
1.
Inject 140% of the base current (that is, 1.4 · 0.587A = 0.822A at 50Hz for this SCB) in phase
L1only.
2.
Check that function binary output signals STHIDML1 and STHOL are set to one.
3.
Check that function binary output signals TRHOL and TRIP are set to one after the expected
time (for example, 15s for this voltage level in accordance with the above table) 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 for current in phase L1, on the local HMI under Main menu /Test is
approximately 411A (that is, 0.822A · (500/1) = 411A).
6.
Check that service value for voltage across SCB in phase L1, on the local HMI under Main
menu /Test is approximately 140%.
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 L2 and phase L3.
10.
Repeat above steps 1 - 8 to test different points from the above table.
Operation of this feature is based on internally calculated peak RMS voltage value. That means that
this feature is also able to operate for current signals with varying frequency. Note that for the
fundamental frequency injection, internally calculated voltage in percent corresponds directly to the
injected current value given in percent. However if it is required to test IDMT characteristic with a
varying frequency, the magnitude of the injected current must be adjusted accordingly. The following
formula can be used to calculate required current RMS value in percent at the desired injection
frequency in order to archive voltage percentage value given in the above table:
[ ]
I
%
inj
EQUATION2274 V1 EN-US
98
Note that during testing the harmonic voltage overload feature the reactive power
overload feature or overcurrent feature may also give start and operate signals
depending on their actual settings. Therefore it is recommended to switch them off
during this test.
1.15
1800
Note that operation of this feature is based on internally calculated voltage peak
RMS value. That means that this feature is also able to operate for current signals
with varying frequency.
f
[ ]
%
=
injected
×
U
f
rated
© 2017 - 2022 Hitachi Energy. All rights reserved
1.2
1.3
1.4
300
60
15
1MRK 505 372-UEN Rev. K
GUID-3C6B2C73-026D-4173-BD4D-1E7E9ADAE160 v3
1.7
2.0
2.2
1
0.3
0.12
GUID-FECBCAD4-16CE-4EFC-9869-9F6D98E2F721 v2
(Equation 14)
Busbar protection REB670
Commissioning manual
Advertisement
Table of Contents
