Comprehensive evaluation method of power quality based on variable weight and set pair analysis

In this paper, variable weight theory and set pair analysis (SPA) theory are applied to comprehensive evaluation of power quality. Among existing comprehensive evaluation methods of power quality, the problems about index uncertainty and imbalance case are less considered. The application of variable weight SPA, for ensuring identical discrepancy contrary (IDC) of unsure system, effectively reduces the complication of assessment process. Variable weight SPA uses the hybrid model of variable weight to modify power quality indices vector, and the final weights of indices could be determined. Then it takes advantage of new weight vector to compute the relativity coefficient of power quality assessment points. Finally the levels of power quality assessment points are assessed by their relativity coefficient. The results of the simulation show that the method used to carry out comprehensive evaluation of power quality is simple, and the classification is detailed. This method could effectively decrease the impact on index uncertainty to assessment results.