Comparative analysis of SVPWM and SPWM techniques for multilevel inverter

Abstract

The aim of this paper is to analyze the comparative relationship between Space-Vector Pulse Width Modulation (SVPWM) and Sinusoidal Pulse Width Modulation (SPWM) for three phase multilevel inverters. Detailed comparative analysis of Total Harmonic Distortion (THD) for both modulation strategies analyzed. The converter technologies are receiving increased attention due to high power applications. This increased attention is probably due to the fact that the output waveforms are much improved over those of the three-phase carrier based sinusoidal pulse width modulation (SPWM).There are various methods of control and modulation methods used for Multi-level inverters. These techniques classified according to switching frequency. The pulse width modulation strategies affects the voltage balancing in the DC bus capacitors as well as the ripple current rating and the capacitance value. Choosing the modulation scheme based upon the control need at hand is very important as it decides the harmonic content of the output voltage waveform. In industries slowly there is an increasing trend of using SVPWM because of their easier digital realization and better dc bus utilization. In this paper both Sinusoidal PWM and SVPWM feeding a RL load are considered. These techniques are studied through simulation using MATLAB/SIMULINK software and the performance of both the techniques are compared.