Comparison of Ssnusoidal and space vector PWM control techniques for three-level inverter drives

Abstract

In recent years, inverters have been the most popular part of electrical drivers in variable voltage and frequency applications. Also multilevel inverters have gained interest in high power applications because of their advantages in high voltage and high power levels with low harmonic content. In this paper, basic structure of three-level inverter is introduced and its two modulation strategies are compared. One of the modulation algorithms is SPWM (Sinusoidal Pulse Width Modulation) technique where a sinusoidal modulation signal is compared with two triangle signals to obtain the three-level at the output phase voltage of the inverter. A simple SVPWM (Space Vector Pulse Width Modulation) algorithm is also realized. In this technique, three nearest vectors can be selected easily and switching sequence and switching times are calculated by using the vector position. Both techniques are simulated by using MATLAB/Simulink package program and applied to the RL and motor loads. Comparative results are given.