论文部分内容阅读
针对现代舰船直流电力系统交流整流发电机保护面临的断路器发电机侧短路时需瞬时分断高上升率短路电流，以及断路器电网侧短路时需短延时后分断短路电流的要求不同这一问题，提出了一种双向非一致混合型真空直流断路器的拓扑结构。采用强迫换流关断原理关断发电机侧短路时高上升率的短路电流，采用自然换流关断原理实现电网侧短路时短延时保护以及正常工作电流的分断。对断路器关断的3个换流过程进行分析，得到了该拓扑结构的最佳连接形式，该连接形式下正、反向关断电流的利用率分别为100%和83%。设计了1 kV/2.5 kA 断路器样机，并进行了正、反向关断试验，实现了正向8 kA的自然换流关断和反向初始上升率为20 A/μs的短路电流强迫换流关断。试验结果表明，所提出方案是有效、可行的，所做的分析准确、可信。“,”The protection circuit breaker of AC rectification generators in modern ship DC power systems faces the problem of different breaking requirements when short circuits occur on different sides of the breaker. The circuit breaker has to cut off the short circuit current with a high rate of current rise immediately when a short circuit occurs on the generator side of the breaker. However, when a short circuit occurs on the grid side of the breaker, a short time delay is required before cutting off the short circuit current. A two direction non-uniform topology of the DC hybrid circuit breaker is proposed, in which both natural current commutation principle and forced current commutation principle are employed when different direction switching off in order to solve this problem. Three commutation processes during the breaking period are analyzed and an optimized connection structure of the topology is achieved, in which the efficiencies of the forced current are 100% and 83% respectively. A high speed contact driving scheme with two driving mechanisms is proposed and prototype of a 1 kV/2.5 kA circuit breaker is developed. Turning off tests of natural current commutation with 8 kA and forced current commutation of the short circuit current with di/dt of 20 A/μs are successfully conducted, which proves the feasibility and effectiveness of the proposed topology.