Hitachi RET670 Commissioning Manual page 210

Section 11
Testing functionality by secondary injection
3. Set the constant input voltage as, UL1 = 63.5∠0° V, UL2 = 63.5∠240° V, and UL3 = 63.5∠120°
V in secondary at rated frequency.
4. Set the constant input current as, IL1 = 0∠0° A, IL2 = 0∠240° A, and IL3 = 0∠120° A in
secondary at rated frequency.
5. Following are the steps to check the operation of Step 1.
Step
No.
5-a
5-b
5-c
6. Repeat
values of input currents as per slope characteristics and the VDepFact2 based on the I>>
value; check the output ST2 and START.
Verification of zero sequence-based operation
1. Set the following parameters:
•
•
•
•
•
•
2. Values of the logical signals and service values for SCCFPVOC 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.
204
The Base values, CT and VT ratios are as follows:
2.1. UBase 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
Step1 operating characteristic verification
Inject constant voltages of UL1 = 1.0∠0° V, UL2 = 1.0∠120° V,
UL3 = 1.0∠240° V and constant currents of IL1 = 0.10∠0° A,
IL2 = 0.10∠120° A, IL3 = 0.10∠240° A in secondary at rated
frequency.
Repeat
Inject constant voltages of UL1 = 57.73∠0° V, UL2 =
57.73∠120° V, UL3 = 57.73∠240° V and constant currents of
IL1 = 1.10∠0° A, IL2 = 1.10∠120° A, IL3 = 1.10∠240° A in
secondary at rated frequency.
Repeat
Inject constant voltages of UL1 = 76.21∠0° V, UL2 =
76.21∠120° V, UL3 = 76.21∠240° V and constant currents of
IL1 = 1.26∠0° A, IL2 = 1.26∠120° A, IL3 = 1.26∠240° A in
secondary at rated frequency.
Step 3, Step 4 and Step 5
Operation = ON
Operation1 = ON (Step 1)
CurrentInput = 3×ZeroSeq
VoltageInput = 3×ZeroSeq
I > = 125% IBase
VDepFact1 = (1-117)/I> = 0.064
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Step 3 and Step 4, to reset ST1 and START.
Step 3 and Step 4, to reset ST1 and START.
for Step 2 operation, by setting Operation2 (Step 2) ON, new
1MRK 504 165-UEN Rev. K
Expected output
ST1 and START signal should be
TRUE
ST1 and START signal should be
TRUE
ST1 and START signal should be
TRUE
GUID-8EAE0867-4161-4BFF-AE89-BE44F374B6A1 v1
Transformer protection RET670
Commissioning manual