高压直流继电器电弧运动仿真分析与实验研究

Simulation Analysis and Experimental Research on Arc Motion in High Voltage DC Relay

电弧是影响高压直流继电器性能的重要因素,研究电弧运动特性及其灭弧措施对提高其电寿命和可靠性具有重要意义。该文基于磁流体动力学(MHD)建立了高压直流继电器电弧等离子体的三维数学模型,对不同外加磁场、不同银蒸气浓度和增设纵向绝缘栅片条件下的电弧运动进行了一系列的仿真计算,得到不同条件下的电弧电压;通过计算弧根的位置坐标对电弧运动进行表征,得到弧根运动曲线。利用高速摄像机拍摄燃弧过程,对仿真结果进行验证。结果表明,触头烧蚀产生的银蒸气不利于电弧的熄灭并阻碍电弧运动;外加磁场作用下触头断开后的一段时间内,电弧在较小范围内做随机运动,是造成烧蚀的主要阶段,增大外加磁场有利于缩短随机运动时间;增设纵向绝缘栅片将提高电弧电压,加快电弧的熄灭。

The electric arc is a critical factor affecting the performance of high voltage DC(HVDC) relay. It is necessary to study arc motion characteristics and arc extinguishing methods to improve its electric life and reliability. A three-dimensional mathematical model of arc plasma of HVDC relay was established based on magnetohydrodynamics(MHD). The simulations on the characteristics of arc motion were carried out under different external magnetic fields, different concentrations of silver vapor and additional axial insulated plates. The arc voltages under different conditions were obtained. The arc motion was characterized by the position coordinates of arc roots, and the curve of arc root motion was obtained. The arcing process was captured by high-speed camera to verify the simulation results. The results show that the silver vapor generated from the contacts hinders the arc movement and extinction. The main stage of arc erosion is that the arc moves randomly in a small range after the contact is broken under the effect of an external magnetic field. Increasing the applied magnetic field intensity is beneficial for shortening the random motion time. The addition of axial insulated plates will increase the arc voltage and accelerate the extinction of the arc.