Surge arresters for Ultra High Voltage transmission system - a review

Extensive research on the Ultra High Voltage (UHV) Technology has been carried out in countries like Italy, United States of America, Russia (the former USSR), Japan, and China. In this paper features of the UHV systems developed by various utilities are discussed. Insulation Coordination studies are essential to compute the overvoltages on the system equipment and to decide on protection measures. This paper provides the insulation levels of system equipment and rating of the surge arresters considered by various utilities for UHV Transmission. The comparison with the protection levels of the arresters shows that the improved system protection against lightning and switching surges is attainable using certain schemes. The research outcomes of the UHV projects carried out by utilities may be helpful for the development of international UHV transmission technology.