A hybrid DC circuit breaker based on a generalized H-bridge circuit

Abstract

Given the rapid development of multi-terminal DC power grids and the treatment of DC faults， a high-voltage hybrid DC circuit breaker based on a generalized H-bridge circuit is proposed. Given the bidirectional current flow of the H-bridge circuit structure， the transfer switch and main disconnecting part are multiplexed in the form of a diode H-bridge， and the common anti-parallel diode is eliminated， so that the required insulated gate bipolar transistors （IGBTs） are reduced dramatically with DC fault clearing capability unchanged. To verify the effectiveness of the hybrid DC circuit breaker based on a generalized H-bridge circuit and its fault isolation method， a four-terminal DC grid test system is built on the PSCAD/EMTDC， and its feasibility is verified by simulation. Moreover， the scheme is compared with other schemes in terms of topology and device cost. The results show that the scheme is very economical.

Keywords

• dc power grid
• hvdc circuit breaker
• dc fault isolation
• circuit breaker cost