Comprehensive evaluation of voltage stability based on EW-AHP and Fuzzy-TOPSIS

Large-scale voltage collapse incidences, which result in power outages over large regions and extensive economic losses, are presently common occurrences worldwide. Therefore, the voltage stability analysis of power systems has become a topic of increasing interest. This paper firstly presents a comprehensive evaluation method for conducting static and transient voltage stability analysis in electric power systems. To overcome the limitations associated with single-index systems in the evaluation of voltage stability, the analysis approach employs a multi-index system with four primary criteria based on separate analysis methods with ten sub-criteria based on individual indices. In addition, this paper proposes a comprehensive method for establishing index weights, which combines the subjective analytic hierarchy process weighting method and the objective entropy weighting method. An innovative index-weight optimization method based on the Lagrange conditioned extreme value is presented and sensitivity analysis is applied to test the robust of the proposed method. Finally, Fuzzy-TOPSIS is employed to rank the voltage buses of a power system as the final results, considering system functionality and proportionality. The results obtained for an actual power grid in Hami City, China demonstrate that the proposed method represents an effective approach for determining the weakest bus in power systems.