ABB RET670 - Measuring the Operating Limit of Set Values

Table 27: Test points for phase-to-phase loops A-B
Test point Value Comments
1 X X1
R 0
2 X 0
R RLdFwd
3 X 0.85·X1 R=0.491·X1+0.5 RFLdFwdPP
R 0.85·X1·1/tan(60°)+0.5
RFLdFwdPP
4 X 0.85·X1
R -0.85·X1·tan (AngNegRes-90°)
5 X 0.5·RFLdFwdPP·tan (ArgLd)
R 0.5·RFLdFwdPP
6 X -0.5·RLdFwd·tan (ArgDir)
R 0.5·RLdFwd
The table showing test points for phase-to-phase loops is used together with figure 32.
11.4.6.1 Measuring the operating limit of set values
Procedure:
1. Supply the IED with healthy conditions for at least two seconds.
2. Apply the fault condition and slowly decrease the measured impedance to find the
operate value for of the phase-to-ground loop ECG, test point 1, according to figure
31. Compare the result of the measurement with the expected value according to
table
26.
The corresponding binary signals that inform about the operation of the phase
selection measuring elements are available in the local HMI under
Main menu/Test/Function status/Impedance Protection/PhaseSelection(PDIS,
21)/FRPSPDIS:x .
3. Repeat steps
1 to 2 to find the operate values for the remaining test points according
to figure 31 and table 26.
When the load encroachment characteristic is deliberately set very
high in order not to have an influence, then the test points 2 and 5 can
be replaced by test point 7.
4. Repeat steps 1 to 3 to find the operate value for the phase-to-phase fault in A - C
according to figure 32 and table 27.
1MRK 504 165-UUS - Section 11
Testing functionality by secondary injection
Transformer protection RET670 2.2 ANSI 131
Commissioning manual