Zero-Sequence Voltage Suppression and Fault Arc Extinction Considering Three-Phase Parameter Asymmetry for Hybrid Grounding System

In scenarios characterized by three-phase parameter asymmetry, the zero-sequence voltage generated at the neutral point under normal operating conditions adversely impacts fault detection in low-resistance grounding systems. Additionally, traditional arc extinguishing methods that rely on current injection often leave the residual voltage, resulting in incomplete fault clearance. This paper addresses these challenges by presenting a hybrid grounding system that integrates a neutral point voltage regulation unit with low-resistance grounding. Specifically, enhanced strategies for mitigating zero-sequence voltage caused by three-phase parameter asymmetry and for effectively extinguishing single-phase ground faults are introduced. By injecting an appropriately controlled current through an inverter, this approach ensures rapid detection of low-resistance ground faults under normal operating conditions and achieves complete arc extinction during high-resistance ground faults, thereby enhancing the reliability of power supply in distribution networks. The sufficient results based on simulation, hardware-in-the-loop and 10kV hardware platform validated the effectiveness of the proposed method.