le Roux, Robert

Application & Field Experience with Metal Oxide Surge Arresters

Dr. le Roux is an Electrical Specialist with a range of engineering skills and practical experience obtained internationally when it comes to specifying primary plant equipment. He has a track record working on large-scale HVDC, power plant and civil engineering projects and has been involved in such projects for ESB EMP in Ireland and ESB International in Bahrain and Southern Africa. He is co-author of several chapters in the CIGRE Green Book on Switching Equipment, including one devoted metal oxide surge arresters, and Convener of CIGRE WG A3.39.

Metal oxide surge arresters have become revolutionized in terms of application and expected performance in areas of higher stress levels. This has resulted in confidence in their reliability and offered new possibilities for overvoltage protection and improved management of power system disturbances. CIGRE Working Group A3.17 evaluated different stresses on MOSAs and also reviewed relevant test procedures, including investigation into the state of present designs. This presentation reviews the historical development of modern MOSAs and describes their interaction with system conditions and ambient stresses. The basics of the metal oxide material as well as of the various arrester designs on the market are also explained.