Control strategy and experimental verification of hybrid DC circuit breaker

XIE Feng, JIANG Daozhuo, WU Zhenliang, CHEN Ke

(College of Electrical Engineering, Zhejiang University, Hangzhou 310027, China)

Abstract: Aiming at the problems of high loss and difficulty in control of existing currentlimit hybrid DC circuit breaker, the working principle, shortcircuit fault breaking and control protection strategy of a DC circuit breaker topology with small inductance structure in series with mechanical switch was studied. The topology of the new type currentlimit hybrid DC circuit breaker was developed, and its prototype platform was built. The processing of different modules in the prototype was analyzed and introduced in detail. Finally, through a reasonable control strategy, some verification tests such as normal switch breaking and shortcircuit breaking was done on the prototype. The results indicate that the new currentlimit hybrid DC circuit breaker has excellent characteristics of accelerating the conduction of solid state switch in shortcircuit commutation and cutting of the shortcircuit fault quickly and effectively, at the same time, it also reduces the complexity and difficulty in control of the circuit breaker, and has obvious technical and cost advantages.

Key words: hybrid DC circuit breaker; prototype experiment; shortcircuit fault judgement; control strategy