Measuring The Operating Limit Of Set Values - Hitachi RET670 Commissioning Manual

Section 11
Testing functionality by secondary injection
Table 28:
Test point
1
2
3
4
5
6
The table showing test points for phase-to-earth loops is used together with figure 33.
Table 29:
Test point
1
2
3
4
5
6
The table showing test points for phase-to-phase loops is used together with figure 34.
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-earth loop L3, test point 1, according to figure 33. Compare the result
of the measurement with the expected value according to table 28.
The corresponding binary signals that inform about the operation of the phase selection
measuring elements are available in the local HMI under
116
Test points for phase-to-earth loop L3-E (Ohm/loop)
Value
X [X1+XN]
R 0
X 0
R RLdFw
X 0.85·[X1+XN]
R 0.85·[X1+XN]·1/tan(60°)+RFFwPE
X 0.85·[X1+XN]
R -0.85·[X1+XN]·
tan (AngNegRes-90°)
X RFFwPE·tan (ArgLd)
R RFFwPE
X -0.5·RLdFw·tan (ArgDir)
R 0.5·RLdFw
Test points for phase-to-phase loops L1–L2
Value
X X1
R 0
X 0
R RLdFw
X 0.85·X1
R 0.85·X1·1/tan(60°)+0.5 RFFwPP
X 0.85·X1
R -0.85·X1·tan (AngNegRes-90°)
X 0.5·RFFwPP·tan (ArgLd)
R 0.5·RFFwPP
X -0.5·RLdFw·tan (ArgDir)
R 0.5·RLdFw
© 2017 - 2022 Hitachi Energy. All rights reserved
1MRK 504 165-UEN Rev. K
Comments
XN=(X -X )/3
0 1
R≈0.491·(X1+XN)+RFFwPE
Comments
R=0.491·X1+0.5 RFFwPP
GUID-B1B7DEB6-7BC3-4A90-8D8F-E4E69B434AFA v3
Transformer protection RET670
Commissioning manual