MONITORING
4–298
Figure 4-124: Power Factor Conventions
Lead PF=-1
-P
Lag PF=1
In a synchronous machine, this type of machine can operate in lagging (under excitation),
leading (over excitation) or unity power factor conditions depending on the applied field
current. As shown in below figure, V-curves are normally provided by the machine
manufacturer to determine the relationship between the filed current and power factor.
Figure 4-125: Synchronous Machine Simplified V-Curve Example
Path:
Setpoints > Monitoring > Functions > Power Factor
TRIP FUNCTION
Range: Disabled, Trip, Configurable
Default: Disabled
This setting enables the Power Factor Trip functionality.
TRIP LEAD LEVEL
Range: 0.05 to 1.00 in steps of 0.01
Default: 1.00 Lag
This setting specifies the Power Factor Lead Trip level.
+Q
Trip Lag PF
Lag PF=1
Lead PF=-1
Normal
Operating Zone
Trip Lead PF
-Q
869 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: SETPOINTS
+P