© 2020 HIOKI E.E. CORPORATION
A_UG_PW0003E02
AC/DC type
AC Type
Power Analyzers
PW6001, PW3390
Power Meters
3333
3334
Power Quality
Analyzers
Voltage, Current, and Power Measurement for Cycle-controlled
Loads, Phase-controlled Loads, and Inverters
Please use a suitable power meter for cycle-controlled loads, phase-controlled loads, or inverter
measurements for measuring voltage, current, and power.
1. Measurement on cycle-controlled loads
-1. Power meters that are suitable for the measurement
As shown in the figure below, an AC/DC type power meter is suitable for measuring
cycle-controlled loads in which the voltage waveform is turned on and off at every half-wave.
Cycle-controlled load measurement
Suitable Power Meters
Power Meters PW3337, PW3336,PW3335,
PQ3198, PQ3100
Non-suitable Power Meters
Clamp-on Power Loggers PW3365
PW3360
3169
© 2020 HIOKI E.E. CORPORATION
A_UG_PW0003E02
-2. AC-type power meter for cycle-controlled loads on the primary-side measurement
0A 0A
実際
の波形 ACカップリングされた波形
ACカップリングされて
いるため、ゼロ点がシフト
The actual current waveform The AC coupled current waveform
The zero point is shifted
The AC type power meters are also compatible on measuring active power and voltage on the
primary side.
(1) Voltage U
Most of the time the voltage waveform on the primary side is a normal AC waveform, so the
measurement is possible.
(2) Current I
For the AC type power meter is there will be an AC coupling on the measured current
waveform. The zero point will be shifted when the waveform is turned on and off at every
half-wave. The waveform will look like a DC components superimposed on each other and
the RMS value cannot be measured accurately.
(3) Active Power P
The active power is calculated from voltage and current waveform.
It is calculated from the same frequency component. Even-though there is a DC
components superimposed on the current waveform, there is no superimposed
components on the voltage waveform. Thus, the active power can be calculated
accurately.
(4) Reactive power Q, Apparent power S, Power factor PF
The apparent power S, the reactive power Q and the power factor PF are calculated from
the from the RMS value of the voltage and current.
The Apparent power S＝Voltage RMS value U (primary side value)×Current RMS Value I
Reactive Power Q＝√(Apparent Power S
2
－Active Power P2)
Power Factor PF＝Active Power P/Apparent Power S
due to the ac coupling
Since the apparent power S, the reactive power Q and the power factor PF are calculated
from the from the RMS value of the voltage and current, this will not give you an accurate
measurement.
Loading...