Alstom SHPM 101 - Sequence Comparator Voltages for MHO Characteristic; Comparator Logic Variables

SERVICE MANUAL R5888C
QUADRAMHO Chapter 2
Appendix A
Page 30 of 71
Figure 30: Comparator logic variables
Figure 29: Sequence comparator voltages for MHO characteristic
X
I Z
V =
I Z
V
POL
= V –90°
V = I Z
Fault outside
characteristic
Fault on boundary
Fault inside
characteristic
IR
AB
A
B
AB AB AB AB AB
Restrain condition
AB
A
B
AB AB AB AB AB
Operate condition
Sine wave
inputs
A + V –
I Z
B = V –90°
Squared
inputs
Logic states