부산대학교 도서관

With the development of flexible DC transmission systems, DC distribution systems applying modular multi-level converter (MMC) are gradually becoming a new trend in the development of future distribution networks. But the fault problem of this system is also more serious. Firstly, the transient characteristics of a bipolar short-circuit fault occurring in the DC line of a double-ended flexible DC distribution system are analyzed, followed by a new distribution structure that can effectively suppress the overcurrent, which can effectively suppress the current growth rate of the MMC bridge arm and facilitate the DC circuit breaker to cut off the fault current, and finally, based on the double-ended flexible DC distribution system built in PSCAD/EMTDC, the proposed structure is verified to be validity.