NF DP060LM, Instruction Manual, Page: 146 / 307

4. Advanced Operation
PROGRAMMABLE AC POWER SOURCE 128
4.4 Measuring Harmonic Current
4.4.1 Harmonic current
Some electric devices of AC power input have its input current waveform greatly distorted from the
sine wave. When the power input section uses a capacitor input type rectifier circuit, the input current
typically distorts as shown in Figure 4-20. A waveform distorted like this contains many harmonic
components. If a current with many harmonic components is supplied to the power line in high
volume, the line voltage is distorted, causing problems such as malfunction of devices and
overheated transformer which may result in accidents.
電圧
電流
Voltage
Current
Figure 4-20 Current Waveform Containing Many Harmonic Components
4.4.2 Basics
Harmonic current measurement function is available only for the Continuous function, AC-INT, and
set frequency of 50 Hz or 60 Hz.
The harmonic current components up to order 40 are displayed as the RMS and a percentage to
fundamental wave component.
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Notes ------------------------------------------------------------------------------------------------------------
 The Harmonic current measurement function does not support the standard tests defined by
organizations such as IEC. Use this function for a preliminary testing.
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