A capacitive high voltage DC circuit breaker incorporating a current limiting function

Abstract

DC circuit breakers， as one of the vital devices for fault clearance in DC power systems， significantly influence the secure and stable operation of the system. Given the problem that most circuit breakers lack fault current limiting capability and are comparably expensive， this paper proposes a design for a capacitive high voltage DC circuit breaker incorporating a current limiting function. By utilizing the charging and discharging characteristics of capacitors， current limiting reactors and lightning arresters can be switched， significantly reducing the peak value of fault current. The extensively used IGBTs in conventional DC circuit breakers are replaced by capacitors， effectively reducing the cost while retaining the current cutout capability. A single-ended equivalent model is developed using PSCAD/EMTDC software， and simulation is conducted. The simulation results show that， compared with traditional high-voltage DC circuit breakers， the proposed scheme reduces the peak value of fault current and shortens the fault isolation time. It demonstrates pleasing performance.

Keywords

• hybrid circuit breaker
• fault current limiting
• topological structure
• pre-charging