Research on Master-Slave Protection Scheme of Distribution Network based on Multi-point Information

Abstract

Considering the advantages of flexibility, economy and environmental protection, the proportion of distributed generation(DG) in distribution network is gradually increasing in recent years. However, the large-scale access of distributed power supply also leads to more and more complex distribution network structure. The traditional distribution network protection scheme is difficult to meet the current needs of protection. Therefore, this paper proposes a master-slave protection scheme based on multi-point information of distribution network. After the fault occurs, the slave protection device located at the feeder terminal collects the positive sequence vector signal of the fault current. It uses the rubber phase angle feature of the positive sequence current phasor ratio for fast local protection. Then the fault direction and switch action information are transmitted to the master protection device. The master device collects the slave device’s information of the system to form a node-branch relation matrix. The fault section is judged by the characteristics of the elements in the matrix. Combined with master and slave device protection action, a master-slave protection scheme of a distribution network based on multi-point information is formed. Finally, the protection scheme is simulated by PSCAD/EMTDC simulation software, and the simulation results verify the reliability of the scheme