Reduction of harmonics at output of three-phase VSI using PSO based PWM technique

Abstract

This paper presents the particle swarm optimization based harmonic elimination pulse width modulation (HEPWM) technique for three-phase voltage source inverter (VSI) to reduce predominant lower order harmonics at its output. The switching strategy of power semiconductor devices of VSI decides the nature of its output voltage. In this regard, the switching strategy can be broadly classified as lower and higher switching frequency pulse width modulation (PWM) methodology. In this paper, lower switching frequency HEPWM is adopted to reduce switching losses in VSI as well as significant lower order harmonics are almost eliminated. For obtaining the required HEPWM waveform, the switching angles are computed using PSO technique so that the THD up to 43rd order harmonics are considered to be minimized at different values of fundamental component. The PIC microcontroller is used to generate HEPWM signals which are applied to the VSI in hardware platform.