YOKOGAWA WT5000 - Equation for Corrected Power (Pc Formula)

8-10
IM WT5000-01EN
Equation for Corrected Power (Pc Formula)
Some standards require that a voltage transformer’s active power be corrected when the load connected to the
voltage transformer is very small. You can select an equation to use for this correction and specify the coefficient.
Applicable Standard (Pc Formula)
Select from the following.
• Type 1 (Type 1): IEC76−1 (1976)
• Type 1 (Type 2): IEC76−1(2011)
Equations for each applicable standard
P
P
1 + P2
Urms
Umn
2
Pc =
P
Umn
− Urms
Umn
1 +
Pc =
Type 1: IEC76-1(1976) Type 2: IEC76-1(2011)
Pc: Corrected Power
P: Active power
Urms: True rms voltage
Umn: Voltage’s rectified mean calibrated to the rms value
P1, P2: Coefficients specified by the applicable standard
Coefficients (P1 and P2)
You can set coefficients P1 and P2 to values within the range of 0.0001 to 9.9999.
The IEEE C57.12.90-2010 equation is the same as IEC761 (1976).
8 Computation Function