钻石型配电网的保护与自愈策略分析

为提升钻石型配电网供电可靠性，配网二次保护系统引入自愈方案。首先，在变电站出口和开关站母线分段处配置不同类型的自愈终端，通过线路光纤差动保护、简易母差保护和分支线过流保护协同，采用光纤手拉手连接的通信模式，确保实现故障的精确定位和快速隔离。其次，优选环内联络开关自愈控制，辅以站间备自投，由此实现正常态单一故障、检修态单一故障和正常态双重故障时，处于非故障段负荷的快速复电。仿真结果表明：所提方法能在最小范围内定位和隔离故障，在0.5 s内恢复非故障段负荷，从而满足供电可靠性需求。

Protection and self-healing strategy analysis of a diamond type distribution network

To improve the reliability of a diamond type distribution network, a new self-healing strategy for a secondary protection system is introduced. First, substation outlets and bus sections in switch stations are equipped with different kinds of self-healing terminals, which include line optical differential, simple bus difference and branch line overcurrent protections. The communication mode is optical fiber hand-in-hand connection. Thus accurate fault location and rapid isolation are achieved. Then, the self-healing control of the connective switches in the ring is instituted, supplemented by automatic device transfer between stations. The load in the non-fault section can be recharged rapidly when a single normal or maintenance fault, or double normal faults occur. The simulation results show that the fault can be located and isolated in the minimum range and the non-fault section load recovered within 0.5s, thereby meeting reliability requirements. This work is supported by the Science and Technology Project of the Headquarters of State Grid Corporation of China (No. 52094020000Y).