Thermal analysis of a submodule for modular multilevel converters

This paper presents a loss calculation method based on the selection of IGBTs and Diodes, and on an analysis of conduction and switching losses in multilevel pulse width modulation (PWM) systems. A comparison between the Modular Multilevel Converter (MMC) and other multilevel topologies, adapted to medium voltage applications, will thus be presented in order to highlight issues such as thermal disparity within the power modules. The proposed method is applied to the MMC topology to show the impact of the variation of different operation parameters on the thermal behaviors, especially with that of AC and DC currents.