A study of ferranti and energization overvoltages case of 500 kV line in Thailand

摘要

Since 1989 the first 500 kV line established, BOAT (Electricity Generation Authority of Thailand) has constructed a number of 500 kV lines.Therefore the study related to the overvoltages are necessary to ensure the safe operation. This paper presents the study results related to the Ferranti and Energization Overvoltages that could be effected by some factors.In BGAT 500 kV lines normally the shunt reactors are adopted at line's two terminals. Meanwhile the surge arresters also have been installed at line's two terminals in parallel with the shunt reactors. The reclosing resistor of circuit breaker is alsoattached in some case. Ferranti overvoltages and Energization Overvoltage are the most common overvoltages in the EHV systems. As these components can effect on the values of overvoltages, the study of the effect of these components, Shunt Reactor, SurgeArrester, Reclosing Resistor, on the Ferranti and Energization Overvoltages should be carried out before the particular line to be commissioned.