Synthetic evaluation of steady-state power quality based on combination weighting and principal component projection method

Abstract

With integration of renewable energy and use of non-linear loads in power systems, the power quality problem is increasingly attracting attention of researchers. In China, standards for individual power quality indexes are set. However, when evaluating power quality in practice, individual indexes cannot directly reflect a comprehensive level of power quality. In this paper, a comprehensive analysis of various indexes is conducted to obtain a unified parameter for describing the characteristics of power quality from an overall perspective. First, weight values of power quality indexes are calculated by combining the subjective and objective weight. Then, based on the principal components of the projection method, projection values of boundary data and data to be evaluated are obtained. Finally, using these projection values, a grade range for power quality data is located. A practical case study is presented to show the validity of the proposed method for evaluating power quality.