Designing insulation coordination for Ultra High Voltage AC system by analyzing over voltages using frequency dependent line modeling

The Insulation coordination is one of the important criteria for designing Ultra High Voltage system. The method to design insulation coordination of any Ultra High Voltage system needs stress analysis and its comparison with the design strength of the equipment. In this paper types of overvoltages in Ultra High Voltage system, process of insulation coordination, frequency dependent line modeling and simulation using Electromagnetic Transient Program (EMTP) & design of insulation coordination for 1200 KV AC transmission line have been presented. The technique to reduce stress have been suggested by using Surge Arrester (SA) is examined.