Breaking Parameter Influencing Factors of Hybrid DC Circuit Breaker Applied to DC Power Grids

Abstract

The breaking parameters of High-voltage DC circuit breakers (HVDC-CBs) in DC grids are the prerequisites for the research and design of circuit breakers, and the study of its influencing factors is of great significance to the collaborative design of the system and equipment. This paper extracts the core breaking parameters of DCCBs in DC grids applications based on the principles, then the qualitative and quantitative analysis of the impact of the core breaking parameters from aspects of power grid operation modes, system parameters, fault characteristics, protection coordination and circuit breaker equipment parameters are carried out. An electromagnetic transient simulating model of ±500kV 4-terminal VSC-based DC grids and hybrid DCCBs is built. The simulation results verify that the reactors parameters, grounding design, protection timing and reclosing action logic of DCCBs have different degrees of influence on the breaking parameters. The multi-parameter optimization will effectively improve the technical and economic performance of the system and the DCCBs. The analysis methods and results provide a reference for the design of hybrid DCCBs.