Impact of the Access of Distributed Generation on Distance Protection and the Reclosing of Distribution Network

Traditional distribution network is unilateral power and radial structure, which will become dual or multiple power supply system by the access of distributed generation (DG), and impact its distance protection and reclosing. The theoretical analysis are verified by modeling and simulation based on Digsilent. The conclusions are: 1) When the DG is not located between protection and fault node of the line, the access of DG will not affect the distance protection. Otherwise, its impacts of the access of DG on protection are discussed in two cases, its access to bus and to line. 2) Permanent fault or asynchronous reclosing may occur when reclosing acts in distribution network with the access of DG, which will cause huge impulse current, destroy electrical equipment, and influence the supply reliability of distribution network.