含直流断路器的±10 kV环网型柔性直流配电网故障暂态特性研究OA

VSC⁃DC distribution networks are highly favored due to their outstanding advantages in power quality,power supply efficiency and operating costs.As a new type of power distribution system,the fault transient charac⁃teristics of the VSC⁃ DC distribution require further research and improvement,and the integration of DC circuit breakers has also led to fundamental changes in the fault transient characteristics of the system.For the research on the fault transient characteristics of the ring⁃type VSC⁃DC distribution network with DC circuit breakers,first,an electromagnetic transient simulation model of a±10 kV ring⁃type VSC⁃DC distribution network is constructed.Two system protection action schemes are designed based on the presence or absence of DC circuit breakers.Then,the VSC⁃DC distribution system is divided into four fault zones.Typical fault conditions that require focused study are selected,and the locations of voltage monitoring points are determined.Finally,for the faults in converter valve area and the DC line,the inherent fault transient characteristics without protection and the operating overvoltage tran⁃sient characteristics under two protection action schemes with and without DC circuit breakers are analyzed,and its technical advantages and application prospects are compared.The research in this paper is of great significance to the design of insulation coordination scheme of the ring⁃type VSC⁃DC distribution network.