Estimation of damping resistor in mechanically switched capacitor with damping network at different tuning frequencies during switching

Mechanically switched capacitor with damping network (MSCDN) is a low cost economical device used in power systems to serve the dual purpose of supplying reactive power at the fundamental frequency as well as to eliminate the unwanted harmonics when tuned at the desired harmonic frequency. However, during switching in a high voltage A.C grid, various elements of an MSCDN plant are subjected to transient electrical stresses which may be vulnerable for the insulation. Proper designing of the damping network is therefore key to mitigate the switching transients. Hence, in this contribution transient analysis is performed on an exemplary MSCDN model for various values of damping resistor at different tuning frequencies. Finally, an optimum range of damping resistor values have been proposed for designing a MSCDN plant tuned to different harmonic frequencies.