Comparative Analysis of Series Connected MOSFETs with Single Switch for ZVS Turn On Converter Topology

Series-connected MOSFETs with lower voltage ratings can be an alternative for single high-voltage switches. This paper compares two switch configurations for the soft-switched power converter topology targeted for a 1400V DC grid. The first configuration is a single switch rated at 1700V whereas the other is a series connected two MOSFETs rated at 900V. A buck converter with 1400V and 700V as input and output voltages respectively is taken as a case study. Triangular current modulation (TCM) ensures zero voltage switching (ZVS) at turn-on for all the switches. The analysis shows that the series-switch configuration can have much lower overall losses than the single-switch configuration.