Research On Network Reconfiguration Scheme Considering Units' And Lines' Restoration Reliability

After a large-scale blackout, reasonable and orderly restoration is of great significance for minimizing the loss. Thus, how to determine the recovery of the target skeleton network and its recovery path sequence is the main task of the network reconfiguration. In the network reconfiguration process, the operation of a large number of units and no-load overhead lines are involved. As there is possibility that generators and transmission lines fail to be put in to operation, the reliability research of the restoration process is of great necessity. In recent years, many researches have focused on the restoration order of the generators and transmission lines putting into operation. Admittedly, so finding recovery scheme with superior technical performance and high reliability has practical significance.In this paper, the process of network reconfiguration is investigated specially from the point of switching in transmission lines. Taking lines' operational reliability into consideration, a method of optimizing units' restoration sequence is proposed. Firstly, a severity index in terms of the outage loss criteria is put forward to improve the definition of lines' restoration risk corresponding to reconfiguration scheme. Secondly, a time-step frame of reconfiguration simulation accordant with the actual situation is established by means of interactive simulation between network reconstruction and units' restoration. Next, the model of optimizing units' restoration sequence is constructed based on minimizing lines' restoration risk corresponding to reconfiguration scheme. Then, combined with the previous research results, a multi-objective optimization model is constructed targeting at minimizing unit's restoring risk of the reconfiguration scheme, minimizing the lines' restoration risk of the reconfiguration scheme and minimizing the network topology fitness function respectively and is solved by the cross particle swarm optimization and Floyd algorithm which optimizes the recovery sequence. Obtaining the Pareto-optimal solutions by the multi-objective particle swarm optimization based on crowding distance(MOPSO-CD). Finally, a decision of non inferior solution is made based on the method of fuzzy membership degree. The outcome of its application on the New England 10-unit 39-bus power system indicates that the method proposed in this paper can effectively take units' restoration reliability, lines' restoration reliability as well as the network topology property into full consideration which helps the dispatch operator to make better informed decisions.