Application of Grey Correlation Degree in Estimation of Voltage Sag Loss

Abstract

Voltage sag is one of the modern Power Quality issues, may cause tremendous economic loss. It’s important realistic meaning for researching voltage sag loss. Voltage sag and influence of sensitive equipment are analyzed in the paper. An estimation method of the economic loss of voltage sag based on gray correlation degree is proposed, which takes the sag magnitude and duration as its main characteristic parameters by using the voltage sag tolerance ability of sensitive equipment. The grey correlation degree between the sag magnitude and duration of voltage sag samples and threshold values is calculated based on user’s historical production interrupt costs, and according to the grey correlation degree of voltage sag samples, the economic loss of voltage sag is then converted into the incomplete production interrupt cost. Example analysis shows that economic loss could be effectively estimated by use the method and the method is an effective instruction for PQ evaluation.