Research on a New Reclosing Control Strategy for DC Circuit Breakers

During the operation of overhead transmission lines, temporary faults constitute over 90% of all occurrences. To enhance the security and dependability of power supply and minimize power outage-related losses, investigating the automatic reclosing of hybrid DC circuit breakers is crucial. This study focuses on the hybrid DC circuit breaker as the research subject and conducts an in-depth comparison of the breaker's current transfer characteristics and the voltage across its terminals under various reclosing schemes. Based on this analysis, an innovative reclosing strategy is presented, which employs a hierarchical input approach for the transfer branches. To validate the effectiveness of the proposed strategy, the electrical model and control system of the DC circuit breakers were constructed using Matlab/Simulink simulation software. The simulation outcomes demonstrate that the hierarchical reclosing control strategy has the ability to effectively mitigate overvoltage impulses across the hybrid DC circuit breaker. Consequently, the research findings offer valuable theoretical insights and technical guidance for the practical application of hybrid DC circuit breakers in engineering projects.