Transient Mitigation in Switching Capacitor Banks Using Solid-State Devices
Abstract
Conventional capacitor bank switching frequently produces voltage and current transients that may disrupt operation, accelerate component degradation, and reduce system stability. This study investigates transient mitigation using solid-state switching devices, specifically insulated gate bipolar transistors (IGBTs) controlled by zero-crossing and pulse width modulation (PWM). Numerical simulations were performed in MATrix LABoratory (MATLAB)/Simulink by varying snubber parameters (Rs–Cs), PWM duty cycle, switching instant, and filter configuration. Results indicate that solid-state switching significantly lowers the magnitude of current and voltage surges compared to conventional mechanical switching. Parametric evaluation of the R–L circuit identifies R = 0.01 Ω as an optimal value, balancing initial inrush current limitation with sufficient damping. Furthermore, the configuration of Rs = 12 Ω, Cs = 33 nF, and a duty cycle of 15% demonstrates superior performance by reducing peak current by over 50%, suppressing peak voltage, and minimizing oscillations. These improvements alleviate device stress, enhance stability, and extend equipment lifetime. Compared to manual switching, the IGBT–PWM scheme achieves lower Ipeak, VCE peak, and switching losses while maintaining conduction efficiency. The findings highlight solid-state switching as a promising and practical solution for designing reliable, efficient, and power-system-friendly capacitor bank switching systems.