This book is translated version of a Russian Author's work. The book discusses in enough details the various principles and problems of high voltage engineering and contains valuable information on methods of analysis of over-voltages to serve as a useful material in planning under-graduate and some aspects of post-graduate courses. It contains a detailed account of the Russian practices in the field, a study of which is a must for the designers of future extra-high voltage systems, if they wish to find the most economical and most technically sound solutions to the problems of application of EHV in Indian conditions, the Russian achievements in the high voltage technology being in no way inferior to those anywhere else in the world and climatic conditions in Asian republics of Soviet Union being very similar to that obtaining in many regions of Indian subcontinent. The book will prove useful to the practicing engineer, manufacturers of electrical apparatus and research workers alike.