High efficiency isolated power supply used for hybrid DC circuit breaker in high voltage direct current systems

Abstract

Hybrid DC circuit breaker is one of the most equipment in high voltage direct current (HVDC) systems. It includes numbers of power electronic (PE) devices and high efficiency isolated power supply is required to control these PE devices. The phase-shifted full-bridge (PSFB) converter is a popular topology for isolated power supply. However, the traditional PSFB converter has some well-known drawbacks. To solve these drawbacks, a novel ZVS FB converter is proposed in this paper. In the primary side of proposed converter, four FB switches, two main transformers and one shared capacitor constitute two half-bridge inverters. At the rectified stage, two FB rectifiers are connected in series by sharing diodes. This structure allows the proposed converter to achieve wide zero-voltage switching range and reduced filter requirement, which make the proposed converter well suited for the power supply for hybrid DC circuit breaker. The performances of proposed converter are verified with an experimental prototype.