Topological structure and control strategy of DC distribution network

The feasibility of ring and dual-terminal structures for DC distribution network is discussed and the power equations are deduced and solved for the typical branch of chained DC distribution network. The grid connection of the distributed energy source and energy storage is compared between DC and AC distribution systems and results show that,the connection to DC grid cuts down on the DC / AC converter and filters. Hybrid DC circuit breaker is applied and a coordinated control model of DC distribution network is proposed. The results of simulation with PSCAD / EMTDC for a ring-type DC distribution network under both normal and fault conditions validate that,with the effective control and reasonable scheduling of distributed energy sources,the harm of short circuit fault to system is effectively limited and the short circuit time is decreased,ensuring the operation of DC distribution network more efficient and stable.