A network based protection scheme of distribution system

This paper comes up with a new kind of network based protection scheme for the 10kV loop distribution power grid, making full use of the communication networks to get rid of the disadvantages of the original protection system. The basic principle, main structure and performance feature of the network based protection system are introduced in detail. Hierarchical configuration is adopted to meet the requirement of scale expansion of the distribution system. A protection algorithm based on current differential principle is designed to locate and clear the faults, and it can operate fast and correctly not only in normal conditions, but also in abnormal conditons, such as failing to act, maloperation and communication faults, with the help of association matrix of the grid. A PSCAD/EMTDC & Matlab based simulation platform is set up in the computer, and the simulation results prove the effectiveness of the proposed protection scheme. A practical project in a southern China city is exhibited as well.