Phase-to-phase switching surges on 500 kV unloaded transmission line

With the use of a digital computer, a comprehensive study of phase-to-phase switching surges on 500 kV unloaded transmission line were studied. Investigations have been carried out on the distribution of phase-to-phase overvoltages and the corresponding time-to-crest values during line energisation and re-energisation. Switching-surge control, using preinsertion resistors and shunt compensation and its effect on the voltage magnitude and time-to-crest value, have been investigated. The phase-to-phase risk of failure function has been estimated in each case, given the effect of wave shape under consideration.