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Section 11
Testing functionality by secondary injection
StartVolt UBase
IECEQUATION2436 V1 EN-US
15.
Increase slowly the applied voltages of the previous two phases and note the reset value.
16.
Check that the trip output of the relay is connected to the input channel of the test in order to
stop the injection and measure the trip time.
17.
Inject symmetric three-phase voltages at their rated value and check that the STUV and START
signals reset as well as the trip signals of the function block (TRIP and TRUV).
18.
Instantaneously decrease the voltage in two phases simultaneously to a value 20% lower than
the set operate value (take into account the previous note if VRPVOC is configured in ACT with
the undervoltage seal-in feature).
19.
Measure the definite time delay for the TRUV and TRIP signals and compare it with the set
value tDef_UV.
20.
Check that start and operate information is stored in the event menu.
11.5.15.3
Completing the test
Continue to test another function or end the test by changing the TESTMODE setting to Off. Restore
connections and settings to the original values, if changed for testing purposes.
11.5.16
Average Power Transient Earth Fault Protection, APPTEF
Prepare the IED for verification of settings outlined in Section
11.5.16.1
Verifying the signals and settings
All of the following test will assume the following CT and VT ratios, and IBase and UBase settings:
•
CT ratio 1000A/1A
•
Phase-to-ground VT ratio 70kV/100V
•
Open Delta VT ratio (sqrt(3)*70kV)/100V
•
IBase=1000A
•
UBase=70kV
However, it must be noted that the secondary values given below can be used for most installations
because, usually:
1.
VT rated primary voltage value is equal to the UBase setting (70kV in the given example above)
2.
CT rated primary current value is equal to the IBase setting (1000A in the given example above)
Consequently these two quantities cancel each other in the calculations for the correct secondary
injected quantities. The frequency is not explicitly specified, use the rated frequency of the protected
network (either 50Hz or 60Hz) for signals given below.
178
VT
sec
×
×
VTprim
100
3
If the VRPVOC function is used as an overcurrent protection with undervoltage
seal-in, it is necessary to first inject sufficient current to activate the STOC signal
before the under-voltage step is allowed to operate. In order to achieve that, apply
symmetric three-phase voltages at their rated value and then inject a current IL1
that is 200% higher than the set operation level. Then slowly decrease the voltage
in two phases simultaneously, until the STUV and START signals appear.
The default setting values are used in the following test procedures if not otherwise
stated for a particular test.
© 2017 - 2022 Hitachi Energy. All rights reserved
1MRK 505 378-UEN Rev. K
GUID-8A33AACE-7B89-4981-A872-78044BB1FD0D v2
GUID-079BCF22-469C-42EA-B857-E28154EC13D9 v1
"Preparing the IED to verify
GUID-36A0055E-CA32-4D85-A580-59032B3AC4AE v1
Line differential protection RED670
Commissioning manual
(Equation 96)
settings".
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