IEEE Recommended Practice for Overvoltage and Insulation Coordination of Transmission Systems at 1000 kV AC and Above

Abstract

This recommended practice specifies the procedure for selection of insulation levels of UHV AC transmission lines and substations. It also specifies reliability criterion under switching overvoltage and lightning overvoltage. It also suggests the calculation methods of insulation coordination design. According to the characteristics of UHV AC systems, overvoltages mitigation measures are recommended. Some examples of insulation coordination are presented.