Abstract: In the county-level region, some problems exist in the 10 kV circuit. For example, the length is too long, the branch-line is too many, there are excessive different types of circuits. Those problems can lead to some issues. For instance, when the section-speed setting value could not be set up accurately and triggered the line fault, it might lead to the sectioned switch cannot operate correctly. It would eventually cause widespread power failure. This paper introduced the structure of distributing electric power automation systems, elaborated on the existing matters of the fault section location and isolation problem in distributing electric power automation systems. The research proposed two plans. One is the fault section location and isolation plan based on the FTU longitudinal differential; another is the fault section location and isolation plan based on matrix computation. Both plans could develop the electric power load monitoring and high-speed communication function of the FTU and centralized control station and help to improve the operation and management level of the distribution network from many aspects. Both plans could develop the electric power load monitoring and high-speed communication function of the FTU and centralized control station. They could help to improve the operation and management level of the distribution network from many aspects. For instance, they can realize the accurate location of the network configuration fault, trigger the isolation of network faults rapidly,reduce the scope of power outages, and ensure the supply of power in non-faulty areas.

    Key words: distribution network automation; fault location isolation; FTU; longitudinal differential; matrix operation