Excitation effects of arc grounding fault on PT ferroresonance of distribution networks connected to photovoltaic in high-altitude areas

Power distribution network systems in high-altitude areas with low air pressure are prone to arc grounding fault, and abundant solar resources lead to the access of numerous distributed new energy sources, which further increases the risk of potential transformer (PT) ferroresonance excited by arc grounding fault. This study designed a device simulating the arcing characteristics in high altitude environment, established a Mayr arc model for simulating arc grounding fault, analysed the fault characteristics of PT ferroresonance overvoltage caused by arc grounding, metallic grounding and accessing to new energy in high altitude areas, and compared the effects of connecting damping resistor at the open delta of PT secondary winding and connecting single-phase PT at the neutral of primary winding to suppress ferroresonance under different conditions, which may provide a reference for suppressing ferroresonance caused by new energy access in high altitude areas.