Analysis of efficiency and harmonics for reverse blocking IGBT matrix converters

In this paper, the power loss and harmonic characteristics of matrix converters with reverse blocking insulated gate bipolar transistors (RB-IGBTs) are studied. A simplified simulation model of the RB-IGBT matrix converter is proposed for calculating the power loss and harmonics. In the model, the nonlinear characteristics of the on-state voltage-drop of the RB-IGBT device are taken into consideration, while the switching transients are ignored. The equivalent inductor model consists of four components to display the nonlinear impedance-frequency characteristics. In order to evaluate the proposed model, a matrix converter prototype of RB-IGBTs is used and measurements have been done at various switching frequencies. The experimental results of the total power loss agree with the simulation results well with a maximum error under 10% at the rated power when the switching frequency is lower than 5 kHz. Moreover, the experimental results of the total harmonic distortion (THD) of the output currents match with the simulation results as well. The errors are within 5% when the switching frequency is lower than 10 kHz. Based on the simulation and experimental results, the relationship between the output current THD and switching frequency is analyzed.