Sel SEL-787 - Figure 5.1 Complex Power Measurement Conventions

5.2
SEL-787 Relay Instruction Manual Date Code 20150130
Metering and Monitoring
Power Measurement Conventions
Power Measurement Conventions
The SEL-787 uses the IEEE convention for power measurement. The
implications of this convention are depicted in Figure 5.1.
Figure 5.1 Complex Power Measurement Conventions
Q+ (VAR)
I leads V
W = –
VAR = –
PF = LAG
I lags V
W = –
VAR = +
PF = LEAD
P+ (W)
I leads V
W = +
VAR = –
PF = LEAD
I lags V
W = +
VAR = +
PF = LAG
SEL-787
Relay
Direction of Positive Real and Reactive Power
W1 W2
SEL-787
Relay
Direction of Positive Real and Reactive Power
W1 W2