Transient analysis during switching of mechanically switched capacitor and damping network (MSCDN)

This paper presents computation results of transient stresses during energization of an MSCDN in a 400 kV system. For validation purposes, transient voltages and currents were also estimated analytically before performing a full three-phase simulation using ATP/EMTP program. Following the circuit breaker closing, instantaneous overvoltage changes of high magnitude are observed across the reactor of MSCDN and the rate of rise of these overvoltages was examined. It is known that uniform distribution of such an impulsive voltage across the reactor windings is very unlikely. Consequently, the reactor is susceptible to insulation failure especially in the inter-turn regions.