基于EM填补和加权秩和比的电力系统黑启动决策方法

电力系统大停电后需要安全可靠的黑启动方案进行电力快速恢复，如何从众多黑启动方案中进行优选是一个重要课题。不同于以往完全信息情况下的研究，本文对电力系统黑启动方案评估问题的研究是基于不完全信息情况下进行的，提出一种EM填补和加权秩和比相结合的黑启动决策方法。首先，采用EM算法填补黑启动方案评价空值，得到完备的黑启动评价矩阵；然后，计算指标间的差异性，利用差异性权重法得到各个指标的权重；最后，采用加权秩和比法确定每个方案的评分值，实现黑启动方案的分级和完全排序。本文方法基于广东电网黑启动数据集进行实验验证，实验结果表明，本文方法可以对不完全信息情况下的黑启动方案进行优劣排序，且具有较高准确性。

Black-start Decision Making Based on EM Algorithm and Weighted Rank Sum Ration

Power systems are developed to perform with high reliability, even though, critical outages may trigger a cascade of events ending up in a large-area black out. In order to minimize the economic losses caused by large-area blackouts, an effective and rapid black-start restoration strategy is becoming very important. Black-start is defined as the process that a power system suffered from a complete blackout is restarted through reconfiguring its networks and recovering its loads depending on self-starting units (black-start units), without relying on other systems. In a typical black-start scenario, black-start units provide power to non-black-start units located close to them, critical system loads are recovered when these non-black-start units come on-line, and the re-supplied area is gradually expanded until the entire power system is restored. Evaluating black-start schemes is one of the key issues having impacts on the restoration speed of the power system concerned. Usually power system operators or experts are willing or able to provide only incomplete information, because of time pressure, lack of knowledge or data, and their limited expertise. However, most studies focused on the black-start decision making problem with complete information. In this article, a comprehensive black-start decision making method based on EM algorithm and weighted rank sum ration is proposed, which addresses the issue of evaluating black-start schemes with incomplete information. Firstly, the absent values are imputed by EM algorithm to obtain a complete black-start decision matrix. Then, the difference weight approach is used to determine index weights. Finally, the score of each scheme is computed according to the weighted rank sum ration approach. Based on the data of Guangdong power system of China, experiments are carried out to investigate the effectiveness of the proposed method. Experimental results show that the proposed method can reasonably fill the missing data of the black-start decision matrix, and performs better than the existing black-start decision making methods. This article can enrich the theories of black start decision-making, and can provide series of useful guidance for the decisions of power system operators.