This book offers an insight into the insulation failures in GIS/GIL and provides practical guidance for improving the insulation reliability of epoxy-based spacers. High voltage gas-insulated apparatuses, including gas-insulated switchgears (GIS) and transmission lines (GIL), playing an important role in the global power transmission system. Epoxy-based spacers are key components in GIS/GIL, playing the role of electrical insulation and mechanical support. However, insulation failures frequently occur around the epoxy-based spacers, threatening the safe operation of the electric power system. Three topics make up this book, with seven to nine chapters in each topic. In the first topic, the surface charging and discharging behaviors of epoxy-based spacers are discussed to deepen the readers’ understanding on the insulation problems in GIS/GIL. And the insulation breakdown of epoxy-based spacers is found to be closely related to the electric field distortion under complex operating conditions. In the second topic, original researches on the surface functionally graded materials (SFGM) are presented for relaxing the electric field distortion around the epoxy-based spacers in both AC and DC GIS/GIL, and a series of optimization methods and fabrication techniques for the SFGM spacers are introduced and discussed. In the last topic, the nonlinear conductivity materials (NCM), also known as self-adaptive materials or intelligent materials, are applied as coatings to adaptively regulate the electric field distributions along the surfaces of the epoxy-based spacers. Besides, the concept of the multi-dimensional functionally graded materials (MFGM) is proposed to uniform the electric field distributions in DC GIS/GIL under stationary and transient voltages, exhibiting great potential in the future application.
Boxue Du received the M.E. degree in electrical engineering from Ibaraki University and the Ph.D. degree from Tokyo University of A&T. During 1996 to 2002, he was with The Niigata Institute of Science and Technology, Japan and was an Associate Professor. From 2000 to 2002, he was a Visiting Scientist at Niigata University, Japan. Since 2002 he has been a Professor and Director-founder of the Institute of High Voltage at the School of Electrical and Information Engineering, Tianjin University, China. His research interests are focused on dielectric failure mechanisms of polymer insulating materials, polymer dielectrics for energy storage, electrical insulation technology and application of polymer dielectrics under various extreme environments such as cryogenic, high temperature, high altitude, gamma-ray irradiation and high-intensity magnetic field. He has published 5 books and 25 book chapters in Polymer Dielectrics, and authored about 700 papers and over 210 of them published in IEEE Transactions. He has also served industry and start-ups as a consultant. He is an Editorial Boards Member of High Voltage, Journal of Electronics and Advanced Electrical Engineering, Journal of Modern Power Systems and Clear Energy, Chinese Journal of High Voltage Engineering, Insulation Materials and Electrical Engineering. He is a Fellow of IET, member at several WG in CIGRE and several Standards Committees in IEEE. He is an Associate Editor of IEEE Transactions on Industry Applications, a Subject Editor of IET Nanodielectrics, and was an Associate Editor of IEEE Transactions on Dielectrics and Electrical Insulation and IEEE Access.
