基于磁流体动力学的35kV自脱离防雷装置灭弧仿真

为研究影响基于气吹灭弧原理的自脱离防雷装置灭弧的影响因素，文中基于磁流体动力学理论建立装置灭弧过程的数值仿真模型，研究电流初始相角与装置气流速度峰值对装置熄弧性能的影响，并结合大电流燃弧试验验证模型有效性。研究结果表明，自脱离防雷装置灭弧时间与工频电流初始相角密切相关，在0°~180°电角度区间内，电弧熄灭所需时间随工频电流初始相角的增大而减小。装置气流速度峰值对电弧熄灭具有决定性作用。当灭弧气流速度峰值高于243m/s时，装置可在半个工频周期内有效熄灭电弧并防止重燃；灭弧气流速度峰值低于243m/s时，在装置产气灭弧筒出口处将出现“电弧堵塞”现象导致电弧重燃。研究结论可为气吹防雷装置灭弧性能优化提供理论依据。

Simulation research on arc extinguishing characteristics of 35kV self-detaching lightning protection device based on magnetohydrodynamics

To explore the factors affecting the arc extinction performance of the self-disengaging lightning protection device,a numerical simulation model of arc extinction process of the device based on magneto-hydrodynamic theory is established in this paper. The effect of the initial phase angle of the current and the peak airflow velocity of the device on the arc extinction performance of the device is investigated,and the validity of the model is verified by high-current arc-burning tests. The arc extinction time of the device is related to the initial phase of the current,and it decreases with the increase of the initial phase of the current in the interval of 0°~180° electrical phase. The peak airflow velocity of the device is critical to arc extinction. When the peak airflow velocity of the arc extinction is higher than 243 m/s,the arc can be extinguished in half a period and the re-ignition is suppressed. When the peak airflow velocity of the arc extinction is lower than 243 m/s,the ''arc blockage'' appears at the outlet of the gas arc extinction cylinder of the device,leading to the arc re-ignition. The findings of this paper provide a theoretical basis for optimizing the arc extinction performance of air-blown lightning protection devices.