RMS Measurements and Harmonic Analysis

Category: PQ Theory, Power Quality, PQ Data Analysis, Analyzing Waveforms, PQ Canvass, Harmonics/Interharmonics

Understand the relationship between an RMS value, harmonic amplitudes and the THD for effective current and voltage PQ investigations.

 

The equivalence between time- and frequency-domain analysis of waveforms, and its relationship to THD (Total Harmonic Distortion) is explored here.

 

The RMS (Root Mean Square) value does contain information regarding the waveform’s harmonic distortion.

 

Additionally, it is shown – thanks to Parseval’s Theorem – that the RMS value of a waveform can also be calculated by way of the frequency domain.

 

As harmonics increase, the RMS value of a waveform increases slowly, while the THD increases at a significantly faster rate.

 

This White Paper Includes:

  • Brief Review of RMS Definition
  • Harmonics
  • Parseval's Theorem
  • Effects of RMS Value on THS (and vice versa)

Download White Paper Here