Comprehensive Assessment Of Black-start Schemes Of Power Systems By Group Decision-making And AHP

Resarch on black-start restoration is of great significance in speeding up the restoration process, reducing the burden of restoration control work and minimizing the loss of power outage. Making a black-start restoration sheme is a common practice for power system restoration after blackout. By investigating the evaluation problems of black-start schemes, a new evaluation method based on AHP and Group decision-making is proposed to get the optimal solution by orderly arranging and assessing various schemes. Besides, with consideration of the initial and subsequent restoration effects, a comprehensive evaluation system is established in this paper. During the early stage of black-start restoration, the main technical issues involved is discussed and analyzed, and the early stage restoration efficiency is obtained through a hierarchical model which is built to evaluate the restoration effect. In the network reconfiguration process, the efficiency index is set to be the maximum output with the minimum cost and within the shortest restoration time, the cross particle swarm optimal algorithm together with the shortest paths algorithm are employed to solve this problem. The load restoration process is partitioned into several periods according to the different characteristics of load restoration. In each sub-stage of load restoration, the back-track algorithm is used to find the optimal solution, the power flow calculation and some out-of-limit disposal measures are also done to guarantee the stability of the restoration system. The restoration time of load restoration is used as an index to evaluate the restoration schemes. By the systematic evaluation system and the indexes obtained from each restoration scheme, the restoration plans can be scientifically and directly evaluated. A testing case is given in this paper to demonstrate the validity and feasibility of the method proposed in this paper.