The study on protection scheme for distribution system in presence of distributed generation

The conventional distribution network is radial, and the protection scheme for the traditional distribution system is designed assuming that the system is radial. In recent years, with the increasing use of the distribution generations, the radial network will not maintain. Therefore, the coordination of the radial-network-based protection will not hold. It is required to propose a new scheme to protect the distribution system with DGs. In this paper, an adaptive protection scheme has been proposed to solve this problem. The new scheme is based on high reliability communication system, by installing a computer- based relay in the substation and dividing the distribution network into zones. In order to verify the effectiveness of this scheme, PSCAD/EMTDC and the IEEE 34 node test feeder are used.