The Research Of Failure Restoration And Reconfiguration In Distributed Network

There are a large number of tie and sectionalizing switches in distributed system, so the load restoration in system failure is a large-scale and nonlinear problem. How to get a good restoration scheme in a short time after failure is a hot research. Due to the increase of distributed generation installed in distributed network, it is playing an important role in distributed system. Distributed generations injections in grid will directly influence the reconfiguration result of distribution network. The reconfiguration with distribute generations get more and more attention in research.According to the problems, this paper studies the fault restoration and reconfiguration in distribution network and gets some achievements. The contents in the paper and achievements are as follows:Firstly, a new fault restoration method with a combination of heuristic and random optimization is presented. In the process of optimization, the heuristic method is first used to get an initial recovery scheme when restoring the failure zones, then using the random method to optimize the load to cut on the basis of excision method. If the failure zone can be restored by heuristic method, we can obtain the restoration scheme with a fast speed. If we must cut the load to satisfy the constrains of distributed system, because of the initial recovery plan it can reduce the range to find the best optimization. In this way the time of calculation is decreased compare to the first one. To sum up, the method can ensure the time of calculation in priority and keep the optimization result in a certain extent.Secondly, we put forward a reconfiguration method with distributed generations and reliability index. Based on the influence of distributed power grid and operation mode to the reliability of the grid, we use the virtual power plant to control and coordinate the output power of distributed generations. In the calculation of objective function we consider the reliability index expect for the network loss and switching frequency to make the power network more optimization. The method considers the affections of distributed generations in the process of reconfiguration, and the experimental results can prove that it can decrease a large scale of the network loss. Virtual power plant can participate in electric market and ancillary market by coordinating distributed generations to provide various services for distribution networks and transmission networks.