Dielectric Faults and Failures in Transformers and Reactors

This chapter presents an overview of the methods used for dielectric condition assessment and on some of the materials used with a special focus on liquid-immersed designs for higher voltages (above 52 kV class). It begins by considering the distinct types of dielectric insulation present within transformers and reactors. It continues by considering the analysis of various dielectric condition assessment tools in transformer and reactor reliability and safety. The main part of the chapter is a detailed consideration of various dielectric faults and their effects and detailed consideration of how these can be diagnosed using different condition assessment and monitoring techniques.