Efficiency analysis for RB-IGBT based matrix converters

In this paper power losses of matrix converters with RB-IGBTs are determined by simulation and experimentally. Different commutation strategies are considered. On the one hand the conventional 4-step-commutation, on the other hand the commutation using a switchable freewheeling circuit that simplifies the commutation but comes along with additional switches. The free-wheeling circuit takes over the load current if a matrix switch is switched off. In this way overvoltage due to interruption of inductive load current is avoided. For the determination of the power losses a high precision power analyzer is applied. The practical results are compared with simulation results. The converter efficiency is determined as a function of the switching frequency of the space vector modulation.