Alstom SHPM 101 - Comparison of Polarised Characteristics

SERVICE MANUAL R5888C
QUADRAMHO Chapter 2
Appendix A
Page 40 of 71
Figure 41: Comparison of polarised characteristics
Faulted voltage = 25%
100% self polarised
16% squarewave
cross polarised
16% squarewave
cross polarised
100% cross polarised
Angle of resultant polarising signal [°LAG] relative to pre-fault position
Displacement of faulted-phase voltage [°LAG]
relative to pre-fault position
0 20 40 60 80 100 120 140
140
120
100
80
60
40
20
0
φ
φ
Conventional
16% partially
cross polarised
mho circle
X
Angle of pre-fault voltage
Fully cross polarised
mho circle
Extra resistive
coverage
R
Characteristic