基于综合权重理论和Fuzzy-TOPSIS综合评价的电网静态电压稳定性分析

随着电网建设规模的不断扩大与结构日益复杂,电网电压安全稳定问题日益突出。探讨了一种静态电压稳定性指标综合辨识方法。首先,针对以往单一评估指标而导致的评估结果差异性问题,釆用六种静态电压稳定性指标来表征节点电压稳定性。其次,对指标权重系数进行优化,分析指标权重不确定性因素,引入信息熵与层次分析法计算指标综合权重。同时以综合评价值最大和评价值偏离度最小为目标,构建拉格朗日函数优化权重系数;并采用Fuzzy-TOPSIS对计算结果进行排序。最后选用哈密地区部分电网作为案例,分别计算单一指标与所提的综合指标辨识系统稳定与薄弱母线,验证所提方法的有效性与客观性。所得结果可以为系统运行规划,无功补偿等提供依据。

Static voltage stability analysis of power grid based on comprehensive weight evaluation method and fuzzy-TOPSIS

The problems of voltage security and stability of power grid are becoming more and more prominent with the expansion of power grid and the complexity of structure construction. As a result, this paper discusses a new method for static voltage stability analysis. Firstly, in order to overcome the sidedness limitation of single-index system in the evaluation of voltage stability, six kinds of voltage stability indexes are combined. Secondly, an index weight optimization method is calculated based on uncertainty factor and a comprehensive evaluation method is used which combines analytic hierarchy process method and entropy method to calculate the weight values. Meanwhile, the aim of the optimization of weights coefficient is to maximize the value of the comprehensive evaluation and minimize the degree of deviation at the same time by using Lagrange conditioned extreme value method, and Fuzzy-TOPSIS is used to rank the results. Finally, taking Hami grid as a study case, both single index and comprehensive index for static voltage stability identification are compared to verify the effectiveness and objectivity of the proposed method. The obtained results can be used to provide basis for system operation scheduling and reactive power compensation. This work is supported by National Natural Science Foundation of China (No. 51667020), Key Laboratory Project of Xinjiang Uygur Autonomous Region (No. 2016D03021) and Doctoral Innovation Project (No. XJUBSCX-2015015).