Exact harmonics elimination in PWM multi-module converters

Pulse width modulated (PWM) voltage source converters (VSCs) present unique features such as input-output linearity and control flexibility. However, due to semiconductor devices limitations and high switching losses the use of these converters are still limited to low and medium power level applications. For higher power applications multi-module PWM and multi-pulse converter structures and switching techniques were introduced. This paper combines these two. In other words, a PWM switching technique, which can be implemented on a multi-pulse converter structure, is presented. It is verified that the proposed approach preserves advantages of both multi-pulse and multi-module PWM converters, and can be operated in either PWM or single pulse mode. Simulation and experimental results validate the feasibility of the proposed approach