Study on the Power‐Frequency Arc Extinction Characteristics of Semi‐Closed Short‐Gap Device

ABSTRACT

Multi‐chamber arc‐extinguishing devices have a simple structure and excellent arc‐extinguishing performance; thus, they have attracted considerable attention as lightning protection devices. However, the structural parameters of different models of the aforementioned devices vary, leading to inconsistent protection levels; therefore, the arc‐extinguishing characteristics of their chambers require further investigation. This study employed simulation and experimental methods to analyze the process through which devices with a semi‐closed short‐gap structure extinguish alternating‐current (AC) power frequency (50 Hz) arcs. First, a numerical model of AC arcs was established on the basis of magnetohydrodynamics theory using COMSOL Multiphysics software. This model was then used to simulate the dynamic arc plasma velocity, pressure and temperature within the extinguishing chamber of a device with a semi‐closed short‐gap structure. Subsequently, an experimental platform was constructed to conduct experiments involving extinguishing various magnitudes of continuous AC arcs in a fabricated semi‐closed short‐gap structure. The experimental and simulation results agreed with each other, demonstrating the effectiveness of the developed model. These results indicate that as the magnitude of an AC arc increases, the arc extinction time increases but remains within the time corresponding to half a cycle of the AC waveform.