Identification of Internal, Corona, and Surface Discharges in Electrical Insulation Through their Characteristics: A Case Study in Norfolk

Abstract

This study presents a case investigation of partial discharge behavior in high-voltage insulation systems within the Norfolk electrical distribution network, emphasizing defect classification using statistical descriptors. Internal, surface, and corona discharge indicate the discharges upon application of high-voltage stress. Partial discharges (PD), including internal, surface, and corona discharges, occur in electrical insulation systems subjected to high-voltage stress and are critical indicators of insulation degradation. In this work, an integrated hardware–software system was developed to acquire partial discharge signals and automatically identify the corresponding defect type. A MATLAB-based Hardware and software system will be used to achieve this goal. Corona, internal, and surface discharge analysis of electrical insulation helps us to know the integrity of the electrical system. The following parameters, such as charge magnitude and phase angle, will be investigated and interpreted. In this work, we are keen on identifying and knowing the characteristics of partial, internal, and surface discharge by resolving it in charge magnitude and phase domain using skewness and kurtosis to distinguish them. To carry out this identification process, a technique for acquiring Partial Discharge with high sensitivity was developed. The results demonstrate that internal, surface, and corona discharges can be reliably distinguished using statistical parameters such as skewness and kurtosis in the charge–phase domain.