An arc is the high-temperature discharge plasma produced in the opening process of mechanical switches, which directly affects the breaking capability of a hybrid DC circuit breaker. According to the physical mechanism of an electric arc, the construction of an arc model for simulation analysis is an important technical means in the electrical field. In this study, based on the theory of magneto hydrodynamics (MHD), a gas mechanical switch model of a natural commutation DC circuit breaker with a compound gap is established. The arc motion process under different conditions is simulated and calculated. The influence of different initial pressures, different opening speeds, and different striking currents on the arc voltage characteristics is analysed. The results show that the larger the gas pressure, the smaller the arc volume and the higher the arc voltage. The faster the opening speed, the longer the arc and the higher the arc voltage; with the increase of the current, the arc voltage increases rapidly at a low current, while the arc voltage increases slowly at a high current.

中文翻译：

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燃气机械开关电弧特性仿真与实验研究

电弧是机械开关分闸过程中产生的高温放电等离子体，直接影响混合直流断路器的开断能力。根据电弧的物理机理，构建电弧模型进行仿真分析是电学领域的重要技术手段。本研究基于磁流体力学（MHD）理论，建立了复合间隙自然换向直流断路器的气体机械开关模型。对不同条件下的圆弧运动过程进行了仿真计算。分析了不同初始压力、不同开启速度、不同引弧电流对电弧电压特性的影响。结果表明，气体压力越大，电弧体积越小，电弧电压越高。分闸速度越快，电弧越长，电弧电压越高；随着电流的增加，小电流时电弧电压迅速增加，而大电流时电弧电压缓慢增加。