不同磁场条件下直流接触器电弧开断特性的仿真研究

Simulation Research on Arc Breaking Characteristics of DC Contactor Under Different Magnetic Field Conditions

直流接触器是实现分断、功率切换以及故障保护等功能的关键器件。文中以某直流接触器为例,建立了直流接触器氢气电弧特性仿真的二维磁流体动力学模型,该模型综合考虑了外部负载电路、触头运动以及非均匀外部磁场等因素对接触器电弧特性的影响,仿真研究了不同磁钢厚度下密闭式直流接触器内电弧开断过程中的电流电压变化曲线以及温度场分布。研究结果表明,在不同磁钢厚度的非均匀磁场作用下,450 V/400 A、充气压力为4 atm(1 atm=101 kPa)的直流接触器内部电弧的燃弧时间有所不同,并且随着磁钢厚度增大,磁场强度变强,燃弧时间缩短,磁钢厚度为5.5 mm时的燃弧时间最短。

DC contactor is the key device to achieve the function of breaking,power switching and fault protection.One DC contactor is taken as an example in this paper,a two⁃dimensional fluid dynamic model for hydrogen arc char⁃acteristics simulation of DC contactor is set up.The influence of such factors on external load circuit,contact motion and non⁃uniform external magnetic field on the arc characteristics of the contactor is comprehensively considered in this model,and the current and voltage variation curve and the temperature field distribution in the case arc breaking period of the encapsulated DC contactor with different thickness of magnetic steel are simulated and researched.The research results show that under the action of non⁃uniform magnetic field with different thickness of magnetic steel,the arcing time of internal arc of DC contactor at 450 V/400 A and gas filling pressure of 4 atm(1 atm=101 kPa)is different.With the increase of thickness of magnetic steel,the intensity of magnetic field becomes strong,the arcing time becomes short and the arcing time of the magnetic steel with the thickness of 5.5 mm is the minimum.