Analysis of Carrier PWM Algorithms For Three Phase Four Wire Multi-level Inverter

This paper presents a simple PWM method to control three phase four leg multilevel inverters, which have been developed for supplying electrical power to three phase unbalanced load and for related power active filters. The method is derived from a general correlation between space vector PWM (SVPWM) method and carrier based PWM (CPWM) method. As an advantage, the simplicity and flexibility of the proposed CPWM control can be obtained and the complicated calculations of the 3-D SVPWM concepts can be avoided. The method has been mathematical formulated and demonstrated by simulation results.