A Wide-Range Input Auxiliary Power Supply based on Series-Connected SiC MOSFETs with Active Gate Driver

Abstract

Auxiliary Power Supply (APS) is required to power the Gate Drive Unit (GDU) of IGBTs present in the submodule of a Modular Multilevel Converter (MMC). The input voltage of the APS is taken from the sub module capacitor while its output voltage is integrated with the GDU of the submodule IGBT. Most existing topologies can only power a single GDU therefore requiring two separate APS. This work proposes a novel topology based on single input and multi-output (SIMO) flyback converter with series-connected SiC MOSFETs. The intended application is to power the GDUs of both IGBTs inside one MMC submodule. Active gate driver (AGD) method is adopted to achieve voltage balancing for the series-connected devices. The proposed converter is experimentally verified.