Hybrid Switch with Dynamic Thyristor Control for Fast Arc Extinction in Three-Phase LV Networks

Arc faults in low-voltage three-phase systems are a major hazard for both people and equipment, requiring extremely fast and selective protective measures. This paper presents the concept and simulation analysis of a hybrid arc eliminator that combines multi-section thyristor branches with a fast mechanical short-circuit device. The arc eliminator enables phase-selective arc suppression, ensuring that only the faulted phase is shunted while healthy phases remain in service. Simulations carried out in ATPDraw, supported by experimental reference data, demonstrate effective arc extinction within sub-millisecond to millisecond time scales across the range of inductances typically encountered in real circuits. This study analyzes the influence of circuit inductance on commutation dynamics and arc duration, as well as the distribution of conduction time among thyristor sections to balance thermal stress. A dynamic I2t-based control strategy is proposed to enhance reliability and component utilization, and preliminary perspectives on optimization supported by artificial intelligence are discussed. The results indicate that the arc eliminator can significantly improve personnel safety and equipment resilience, particularly in critical installations such as data centers, mining infrastructure, ships, or photovoltaic and electric vehicle systems.