Practical experience with advanced residual current compensation in a resonance-grounded MV network in Australia for bushfire prevention

Global warming and dry areas significantly heighten the risk of bushfires, making advanced earth fault protection systems crucial for overhead power line networks. Earth faults, or single line-to-ground faults, account for approximately 70% of all faults in power systems and pose a severe risk of fire in hot and dry regions. While traditional earth fault current compensation methods mitigate the capacitive fault current, residual active fault currents may still result in fire hazards, especially in dry regions. To address this, the Advanced Residual Current Compensation (ARCC) system combines Arc Suppression Coils (ASC) and single-phase power inverters to compensate for both capacitive and active fault currents, achieving a near-zero residual current. This ensures compliance with bushfire safety regulations such as those in Victoria, Australia, which mandate a significant reduction in fault voltage to mitigate ignition risks. This paper presents and discusses the performance of the ARCC system installed at AusNet in Australia. Real-world data from controlled earth fault scenarios with different earth fault characteristics are presented to validate the system's reliability and rapid response. The findings highlight the ARCC system’s effectiveness fulfilling bushfire safety regulations in resonance-grounded networks to reduce bushfire risk.