YOKOGAWA wt3000 User Manual

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IM 760301-01E
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App
Index
Power Measurement
Explanation
• Selecting the Equations for Apparent Power and Reactive Power
The equations for apparent power and reactive power can be selected from three types.
For details, see section 2.5.
• TYPE 1 (Method Used by Normal Mode of Conventional WT Series Power Meters)
Active power for three-phase, four-wire system PΣ = P1 + P2 + P3
Apparent power for three-phase, four-wire system SΣ = S1 + S2 + S3 (= U1×I1 +
U2×I2 + U3×I3)
Reactive power for three-phase, four-wire system QΣ = Q1 + Q2 + Q3
• TYPE 2
Active power for three-phase, four-wire system PΣ = P1 + P2 + P3
Apparent power for three-phase, four-wire system SΣ = S1 + S2 + S3 (= U1×I1 +
U2×I2 + U3×I3)
Reactive power for three-phase, four-wire system
QΣ =
SΣ
2
– PΣ
2
• TYPE 3 (Method Used by Harmonic Mode on the WT1600 and PZ4000)
This computing equation can be selected on models with the advanced
computation (/G6) or harmonic measurement (/G5) option. The harmonic
measurement must be performed correctly. For details on harmonic measurement,
see chapter 7 in the Expansion Function User’s Manual IM760301-51E .
Active power for three-phase, four-wire system PΣ = P1 + P2 + P3
Apparent power for three-phase, four-wire system
SΣ =
PΣ
2
+ QΣ
2
Reactive power for three-phase, four-wire system QΣ = Q1 + Q2 + Q3
Note
There are limitations to setting equations for apparent power and reactive power depending
on the measurement mode. For details, see page 2-19.
For example, if you set the equation to TYPE1 in normal measurement mode and switch to
IEC harmonic measurement mode, the equation automatically switches to TYPE3. If you
switch the measurement mode back to normal measurement, the equation automatically
reverts to TYPE1.
• Setting the Equation for Corrected Power
Depending on the applicable standard, when the load that is connected to the potential
transformer is extremely small, the active power of the potential transformer that is measured
needs to be compensated. In such cases, set the compensating equation and the coefficient.
Corrected power (Pc) is a measurement function in the normal measurement mode.
• Selecting the Applicable Standard
Select the standard from below. For the equations of each applicable standard, see
section 2.5.
• IEC76-1(1976), IEEE C57.12.90-1993
• IEC76-1(1993)
• Setting the Coefficient
Coefficients P1 and P2 can be specified.
Set the coefficients in the range of 0.0001 to 9.9999.
Note
Corrected power is computed only when the voltage mode is RMS or MEAN.
5.9 Setting the Equations for Apparent Power, Reactive Power, and Corrected Power

YOKOGAWA wt3000 Specifications

General

Brand	YOKOGAWA
Model	wt3000
Category	Measuring Instruments
Language	English