Adaptability Research and Construction Scheme of DC Distribution Network Topologies

This paper investigates the adaptability and application scenarios of the radial structure, single-terminal ring structure and two-terminal structure, as well as the construction schemes and restricting factors, and the scheduling of renewable energy sources in DC distribution system is studied. Analysis results show that radial topology is mainly applicable to LVDC distribution network and low power reliability areas, and the construction scheme should be selected according to the distributed power permeability, the cost of DC circuit breakers and the load distribution. Single-terminal ring structure is mainly used for centralized sending of distributed power supply, and the converters can be used to isolate the faults, whereas the voltage recovery is relatively slow after fault. Two-terminal and multi-terminal structures can be used for the power supply of the DC load concentrated area. The power flow can be optimized by adjusting the converter control instructions, and the speed of voltage recovery is relatively fast. The electric cable is generally used, and the fault location is accurately judged by DC breakers and optical fiber communication technology.