Research And Implementation Of Distribution Network Multi-objective Network Reconfiguration Method

Distribution System is an important part of electrical power system, and it is also the connection between power generation and users. Distribution automation is one of the most important duties in the smart distribution network construction. Network reconfiguration plays an important role in Distribution advanced application automation. Distribution dispatcher can adjust operation structure through optimizing switch without additional investment. Through network reconfiguration, on the one hand, it can balance load among feeder lines, eliminate overloading and increase quality of supply voltage; on the other hand, it can decrease net loss, and improve efficiency of distribution system operation..This article has built unified reconfiguration framework for many optimizing objects through analyzing and deducing internal relations between objective function and load transmission. At the same time, in order to ensure the safety of power grid and efficiency of operation in the process of reconfiguration, this thesis has considered many factors, such as security constraint of each node, branch current constraint, network topology constraint, refactoring gain threshold. This can slow downdevice aging due to frequent reconfiguration. In the presence of loop in distribution network, which need to be solved by unlinked loop and shift ring. Therefore, this paper proposes a network reconfiguration method based on spanning tree heuristic optimization algorithm to solve the grid containing loops. This method allows the distribution network to form a more optimal network structure, at the same time also makes the network reconfiguration in a wider range. In order to achieve network reconfiguration rapidly and complete loop resistance calculation, this thesis designs a data structure named the switch current connection graph to store distribution network topology, which can ensure feasibility of the realization the network reconstruction. Finally, this thesis proposes an iterative network reconfiguration method based on branch exchange method.In order to verify the correctness and effectiveness of the model and the algorithm proposed in this thesis, IEEE 185 nodes distribution system is used as a numerical example. Finally, the multi-objective distribution network reconfiguration software are implemented in C++ and run as a module in XJ Group Distribution Network Distributed Automation Senior Application System. The real application results show that, the time and space performance can meet the requirements of the state grid corporation of China. Moreover, this software supports the calculation of three state(real time, history and research state) in the practical application. Now, the system has been online running in several cities of Shandong province..