Study on Adaptive Protection System of Power Supply and Distribution Line

To adapt to the requirement of frequent changes of topology structure and unstable operating mode of power system, integrating advantages of adaptive protection device and adaptive protection system, an adaptive protection system of power supply and distribution line of 35 kV or under 35 kV is designed. The basic theory and key technology of adaptive three- step current protection is presented. Three strategies to adapt to the changes of topology structure, operating mode and fault type of power system are presented. Verification rules of sensitivity and selectivity of adaptive protection device are presented. Results of example analyzing and testing indicate that this system has characteristics of powerful adaptive ability and fast setting speed. Its application can improve the sensitivity and selectivity of protective relays, the reliability and security of power supply and distribution line.