YOKOGAWA WT310EH - Harmonic Measurement (Option)

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IM WT310E-01EN
Features
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App
Index
1.6 Harmonic Measurement (Option)
Usingharmonicmeasurement,youcanmeasurevoltage,current,andactivepoweruptothe50th
harmonic; the harmonic distortion factor for each harmonic order; and the phase angle of each
harmonic order with respect to the fundamental wave (1st harmonic). You can also compute the
total rms values (fundamental wave + harmonics) for voltage, current, and active power and the total
harmonic distortion (THD).
For a list of the symbols for the measurement functions that can be measured with harmonic
measurement and their descriptions, see “Harmonic Measurement Functions” under “Items That This
Instrument Can Measure.”
PLL Source (For procedures, see section 6.3)
For harmonics to be measured, the fundamental period (the period of the fundamental signal) that will
be used to analyze the harmonics must be determined. The signal for determining the fundamental
period is the PLL (phase locked loop) source. For stable harmonic measurement, use an input signal
with low distortion and few fluctuations as the PLL source.
For explanations of the terms fundamental wave, harmonics, harmonic orders, and other terms, see
appendix 2.
Measured Harmonic Order (For procedures, see section 6.3)
Youcansettheupperlimitofmeasuredharmonicorderintherangeof2to50.However,therange
varies depending on the fundamental (1st harmonic) frequency. This is because the upper limit of
harmonicsthatarecomputedvariesdependingonthefundamentalfrequency.Thedefaultvalueis50.
Total Harmonic Distortion Equation (For procedures, see section
6.3)
You can select the equation for determining the total harmonic distortion from the options listed below.
Thefollowingexplanationsareforwhentheupperlimitofmeasuredharmonicorderis50.Ifthe
maximumnumberofmeasuredharmonicordersislessthan50,theequationwillbeappliedtothe
harmonic orders up to the specified maximum number.
• IEC:Theratioofthermsvalueofharmonics2to50tothermsvalueofthefundamentalwave(1st
harmonic) is calculated.
• CSA:Theratioofthermsvalueofharmonics2to50tothermsvalueofharmonics1to50is
calculated.