• VoltageInput = negSeq
• I > = 125% IBase
• VDepFact1 = (1-117)/I> = 0.064
2. Values of the logical signals and the service values for SCCFPVOC (51 V) are available on the
local HMI under: Main menu/Tests/Function status/Unbalance protection/
CapBankCascadingFail(51V,2(I>/U<))/SCCFPVOC (51V, 2(I>/U<)):x, where x = instance number.
The Base values, CT and VT ratios are as follows:
2.1. VBase considered is 400 kV
2.2. IBase considered is 3000 A and the calculations are done considering CT
ratio as 3000 A/1 A and VT ratio as 400 kV/110 V
2.3. Rated frequency = 50 Hz
3. Set the constant input voltage as, VA = 63.5∠0° V, VB = 63.5∠240° V, and VC = 63.5∠120° V in
secondary at rated frequency.
4. Set the constant input current as, IA = 0∠0° A, IB = 0∠240° A, and IC = 0∠120° A in secondary at
rated frequency.
5. Following are the steps to check the operation of Step 1.
Step
No.
Step1 operating characteristic verification Expected output
5-a Inject constant voltages of VA = 1.0∠0° V, VB = 1.0∠120° V,VC
= 1.0∠240° V and constant currents of IA = 0.10∠0° A, IB =
0.10∠120° A, IC = 0.10∠240° A in secondary at rated
frequency.
PU_ST1 and BFI_3P signal should
be TRUE
Repeat Step 3 and Step 4, to reset PU_ST1 and BFI_3P.
5-b Inject constant voltages of VA = 57.73∠0° V, VB = 57.73∠120°
V, VC = 57.73∠240° V and constant currents of IA = 1.10∠0° A,
IB = 1.10∠120° A, IC = 1.10∠240° A in secondary at rated
frequency.
PU_ST1 and BFI_3P signal should
be TRUE
Repeat Step 3 and Step 4, to reset PU_ST1 and BFI_3P.
5-c Inject constant voltages of VA = 76.21∠0° V, VB = 76.21∠120°
V, VC = 76.21∠240° V and constant currents of IA= 1.26∠0° A,
IB = 1.26∠120° A, IC = 1.26∠240° A in secondary at rated
frequency.
PU_ST1 and BFI_3P signal should
be TRUE
6. Repeat Step 3, Step 4 and Step 5 for Step 2 operation, by setting Operation2 (Step 2) Enable, new
values of input currents as per slope characteristics and the VDepFact2 based on the I>> value;
check the output PU_ST2 and BFI_3P.
Verification of zero sequence-based operation
GUID-8EAE0867-4161-4BFF-AE89-BE44F374B6A1 v1
1. Set the following parameters:
• Operation = Enable
• Operation1 = Enable (Step 1)
• CurrentInput = 3×ZeroSeq
1MRK 504 165-UUS Rev. J Section 11
Testing functionality by secondary injection
Transformer protection RET670 215
Commissioning manual
© 2017 - 2021 Hitachi Power Grids. All rights reserved
To Next Page
Loading...
