Tripping overvoltages in HV transmission networks equipped with shunt reactors

Last years meant for Romanian power system huge efforts for increasing of its reliability and stability. A national program sustained financially a large-scale upgrading process of power system components. In this paper the authors present the results of an analysis regarding operation of different versions of equipments included in a HV substation. The performed tests outlined the dependency between the chopping current and the overvoltages rising due to switching-off operation of a shunt reactor in the presence of different types of circuit breakers. Further decisions about upgrading the substation components were based on these test results.