A Cumulant-based method for credibility assessment of power system state estimation

Abstract

Although a great amount of achievements on the power system state estimation have been obtained in the past decades, few results about the credibility assessment of state estimation are presented. This paper proposes a Cumulant-based approach to assess the credibility of the estimated results in the case that the true values are unknown. The credibility indicators based on confidence intervals are provided to quantify the accuracy of the estimated results and the validity of the state estimator. The Cumulant method is applied to determine the statistical characteristic of estimated results, so that the confidence intervals can be figured out flexibly. The assessment results are very helpful for avoiding low-accuracy estimation. Results using the proposed method are compared against Monte-Carlo Simulations to demonstrate the accuracy of the results. Then, the validity of the credibility indicators is illustrated. Tests are carried on the IEEE 14-bus system and the IEEE 57-bus system respectively.