Stability Analysis and Optimization of DC Circuit Breakers with Single Gate Drive Scheme for Power System Protection

This research presents an in-depth analysis of small-signal modelling for DC Circuit Breakers (DCCBs), highlighting its significance in power system protection. The study focuses on the stability assessment of DCCBs, particularly when driven by single-gate signals and tasked with managing a series of switch devices. The paper introduces a novel Single-Gate Drive (SGD) scheme, incorporating additional gate diodes to effectively mitigate unwanted voltage oscillations and suppress gate oscillation during the turn-off process. The impact of circuit parameters, such as parasitic inductances and capacitances, on the stability of DCCBs is thoroughly examined. Through simulations, the paper demonstrates that an increase in output capacitance can alter the system's frequency response characteristics while maintaining relative stability. Conversely, higher bus voltages lead to a decrease in the system's damping ratio, enhancing oscillatory tendencies. The findings underscore the necessity of striking an optimal balance between voltage levels and system stability to ensure the reliable operation of DCCBs in protecting power systems from fault currents.