An investigation of the harmonic effects of nonlinear loads on power distributon network

Abstract

Nonlinear loads are loads that defy ohms law. As a result of changes in impedance, the voltage and current waveforms from the loads are distorted and may be unpredictable in behavior. Heavy presence of a nonlinear load or the presence of many nonlinear loads in a distribution network may significantly introduce harmonics into such network. Harmonics are waveforms whose frequency is an integer of the fundamental frequency. When present in large quantity, harmonics may cause adverse effects not only to other loads on the network but also to the power distribution network. This paper investigates the harmonic effects produced by nonlinear loads on power distribution network. Nonlinear and linear loads were modelled and developed. Using MATLAB/SIMULINK simulation technique, the system was observed to be unstable with un-periodic oscillations and the total harmonic distortion (THD) was found to be 112.04% at maximum.