Effects of Total Harmonic Distortion on Power System Equipment

Abstract

Total harmonic distortion, or THD, is the summation of all harmonic components of the voltage or current t waveform compared against the fundamental component of the voltage or current wave: Harmonic is a sinusoidal component of a periodic wave or quantity having a frequency that is integral multiples of the fundamental frequency.. Harmonics can be voltage and/or current related and present in electrical system in multiples of the fundamental frequency. This paper discusses the effects of total harmonic distortion on power system equipment. Various values of fundamental and harmonic voltages were used as input parameters for the computation of THD to establish if their limits fall within the harmonic standards. The results of the paper show that the average value of the THD for the power system equipment is 1.98% which is in agreement with the even harmonic standards of 2%.Keeping low THD values on a system will further ensure proper operation of equipment and longer equipment life span.

Keywords: Total harmonic distortion, Power factor correction, Distribution transformers, Fundamental frequency, Harmonic standards.