HV isolated power supply system for complex multiple electrical potential equipment in 500 kV hybrid DC breaker

Abstract

High-voltage direct current circuit breakers (HVDC CB) are one of the key technologies of multi-terminal DC systems and DC grids. Different from other equipment that use a large number of power electronic devices, the HVDC CB cannot obtain its power from the primary system at high potential, making the power supply of the complex multiple electrical potential equipment in HVDC CB a challenge. In this study, the authors propose an HV isolated power supply system based on the multi-output high-frequency isolated power supply unit and the cascaded isolation transformer network. This power supply system can support the 500 kV CB to turn-off 25 kA current with 800 kV overvoltage.