Investigation on capacitor switching transient limiter with a three phase variable resistance

In this paper, a capacitor switching transient limiter based on a three phase variable resistance is proposed. The proposed structure eliminates the capacitor switching transient current and over-voltage by introducing a variable resistance to the current path with its special switching pattern. This topology has high damping capability due to its resistance nature and low voltage drop and low power losses due to complete bypass of its resistor. Therefore, it does not need auxiliary circuit to compensate voltage drop in normal condition. Also, because of smooth bypass of resistance, it does not make transients on capacitor after bypassing. Analytic Analyses for this structure in transient cases are presented in details and simulations are performed by MATLAB software to prove its effectiveness.