Harmonic Analysis Using FFT and STFT

Abstract

Now a day's Harmonic distortion has been a significant problem to maintain power quality. It is very essential to analyze of power signal and find different harmonics. Some harmonics in the power signals are harmful to sensitive equipments and also causes to power loss. It is therefore important to find such harmonics and use different harmonic mitigation techniques to get clean/pure signal for safe operation of the connected equipments and minimize Power loss. Harmonic distortion is the corruption of the fundamental sine wave at frequencies that are multiples of the fundamental. Aim of this paper is extraction of fundamental and harmonic components in voltage/current signal using FFT & STFT, plot the stylized spectrum of distorted signal in MATLAB with power system frequency and classify the subtypes of harmonics, study the different characteristics and calculate total harmonic distortion (THD) that will be useful for solving problems related to power quality.