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Section 11
Testing functionality by secondary injection
11.6
Voltage protection
11.6.1
Two step undervoltage protection UV2PTUV
Prepare the IED for verification of settings as outlined in section
section
11.6.1.1
Verifying the settings
Verification of start value and time delay to operate for Step 1
1.
Check that the IED settings are appropriate, especially the START value, the definite time delay
and the 1 out of 3 operation mode.
2.
Supply the IED with three-phase voltages at their rated values.
3.
Slowly decrease the voltage in one of the phases, until the START signal appears.
4.
Note the operate value and compare it with the set value.
For phase-to-earth measurement:
U
100
IECEQUATION2430 V1 EN-US
For phase-to-phase measurement:
U
100
IECEQUATION2431 V1 EN-US
5.
Increase the measured voltage to rated load conditions.
6.
Check that the START signal resets.
7.
Instantaneously decrease the voltage in one phase to a value about 20% lower than the
measured operate value.
8.
Measure the time delay for the TRIP signal, and compare it with the set value.
9.
Check the inverse time delay by injecting a voltage corresponding to 0.8 × U1<.
( )
t s
IECEQUATION2428 V1 EN-US
where:
t(s)
k1
U
U1<
182
"Preparing for test"
in this chapter.
The operate value in secondary volts is calculated according to the following
equations:
1
UBase VT
sec
<
×
×
VTprim
3
1
VT
sec
<
UBase
×
×
VTprim
For example, if the inverse time curve A is selected, the trip signals TR1 and TRIP
operate after a time corresponding to the equation:
k
1
=
U
−
1
<
U
1
Operate time in seconds
Settable time multiplier of the function for step 1
Measured voltage
Set start voltage for step 1
© 2017 - 2022 Hitachi Energy. All rights reserved
1MRK 505 378-UEN Rev. K
"Requirements"
and
Line differential protection RED670
Commissioning manual
SEMOD53540-1 v1
M13796-2 v6
M13796-9 v3
M13796-29 v11
(Equation 97)
(Equation 98)
(Equation 99)
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