Active Voltage Balancing Methodology for Series connection of 1700V SiC MOSFETs

Abstract

Series connection of 1.7kV Silicon Carbide (SiC) MOSFETs have potential to become a building block of compact and lightweight Megawatt power converters. These devices with high current carrying capability (56.5A/die) can be connected in series to develop high voltage and current rating power converters. Series connection of power devices generally involves passive voltage balancing methods, such as R-C snubbers, which increases the switching loss in power converters. Therefore, this paper describes the series connection of 1.7kV SiC MOSFETs using Active Voltage Balancing method. Active Voltage Balancing avoids R-C snubbers for minimizing voltage mismatch, thus reducing the switching loss in power converters. An alternative method of Active Voltage Balancing has been discussed in the paper for series connection of two 1.7kV SiC MOSFETs. The proposed method has been verified by simulation and experimental results.