Omicron Lab CT SB2 - 7 CT Testing Using the Guesser Function; 7.1 About the Guesser Function

129
The CT Analyzer Test Cards
Parameters assessed for IEEE C57.13
Param. Description Parameter assessed
for IEC 61869-2
metering CTs
0.1, 0.2, 0.2s,
0.5, 0.5s, 1
3, 5
Class Accuracy class according to standard. x x
Δϕ Phase deviation. x
ε Current ratio error. x x
FS Instrument security factor (direct measurement
method).
xx
FSi Instrument security factor (indirect meas. method). x x
Parameter Description Parameter assessed for
IEEE C57.13 IEEE
C57.13.6
protection CTs,
class
meter.
CTs
0.3, 0.6,
1.2
high
accuracy
metering
CTs
0.15,
0.15s
C T X K
1
1. Acc. to IEEE C57.13 (1993)
Class Accuracy class according to
standard.
xxxx x x
Rct DC winding resistance. x
Δϕ Phase deviation. x x
RCF Ratio correction factor. x x
ε @ Isn
Current ratio error at secondary
current I
sn
.
xxxx
ε @ 20 * Isn
Current ratio error at 20 times the
secondary current I
sn
.
xxxx
Vb Rated secondary terminal voltage. x x x
Vknee Knee point voltage. x
Vk / Ik User-defined measuring point. x x
Vk1 / Ik1 User-defined measuring point 1. x x