Study Of Distribution System Restoration Considering Distributed Generation

With the continuous development of the community, the quality and reliability of the electricity distribution network is in highly demand. In order to meet user requirements and reduce the loss of distribution network caused by distribution network failure, distribution management system and distribution automation system have emerged as an important management tool and effective technologies. One of the most important tasks of the distribution automation system is to locate the breakdown region timely and correctly, isolate the breakdown region quickly and restore the power supply of the other part of the distribution network.Distribution system restoration after faults is a nonlinear optimization problem with multi-objective, multi-stage, multi-constraint. The ultimate solution is a serial of switching operations to give a superior scheme of service restoration with least times of switching operations, highest reliability and least network loss in the constraint conditions of network connected, network radiation and feeder none-overtaxing. The widely used of Distributed Generation technologies is the direction of future development of the distribution system. The large number of emerging Distributed Generation will definitely bring an important influence to the distribution network.This paper starts research work on the distribution system restoration including Distributed Generation. The prime task is as follows:Through the compare and research of existing distribution system restoration algorithms, an algorithm based on tree model with heuristic rule is proposed. According to distribution network's radiating characteristic, algorithm constructs the power cut area to tree model, overall evaluates the two goals include resumes the load as possible as many and On-off operation as possible as few, obtains the optimal restoration strategy by the heuristic rule.Proposed the solution of the distribution system restoration includes the distribution system with multi-power sources as well as has trigger-refused of circuit breakers. This gives the distribution system restoration algorithm a more widespread serviceability.Along with the Distributed Generation technologies unceasing development, the number of Distributed Generation increases day by day in distribution network. When the distribution network including Distributed Generation breaks down, cutting off all Distributed Generations in traditional. This may protect power system's security enormously, however,it has affected the power supply reliability as well as the Distributed Generation's efficiency. Therefore, this paper improved the method by adding the Distributed Generation's processing method into the algorithm. According to the Distributed Generation's characteristic, in the algorithm the Distributed Generation and the load are considered as the distributed micro-gird, this island operation enhances the power supply reliability and speeds up the distribution system restoration.The sample test indicated, the algorithm proposed in the paper is brief, practical and effective.