大功率直流接触器在不同介质中开断电弧特性的实验研究

Experimental Study on Arc Breaking Characteristics of High-power DC Contactor in Different Gases

电动汽车的快速发展和航空系统供电容量的进一步提升对大功率直流接触器提出更高的要求。为了研究大功率直流接触器中密封气体的种类及压强对于接触器开断电弧特性的影响,设计了带单向气阀的桥式直流接触器样机,搭建了直流开断实验平台,测试了不同气体介质和压强下的电弧电压、电流、燃弧时间、燃弧能量等,对比分析了灭弧介质和压强对直流接触器开断特性的影响。结果表明:直流接触器燃弧过程3个阶段中,电弧在触头之间拉长阶段占据了总燃弧时间的60%以上;压强为0.3MPa时,氢气、氮气、氦气3种气体分断200V/1200A的燃弧时间分别为1.20 ms、1.42 ms和1.54ms,氢气电弧电压的峰值远高于其他两种气体,且燃弧能量低,表现出优良的灭弧性能;压强从0.1MPa升至0.3MPa,3种气体的灭弧性能均得到显著提高,表现为燃弧时间缩短17%,燃弧能量降低约15%,电弧运动速度加快。

The rapid development of electric vehicles and the improvement of the power supply capacity of aviation systems pose higher demands on high-power DC contactors.In order to study the influences of the type and pressure of gases sealed in a DC contactor on the arc characteristics during the breaking process,a prototype of the bridge-type DC contactor with a one-way valve was designed and a DC breaking circuit experiment setup was built.The measured data under different gases and pressures,such as arc voltage,arc current,duration time,and arc energy were obtained.The influences of gas medium and pressure on characteristics of DC arc were analyzed in detail.The results show that the arc burning process of DC contactor can be divided into three stages,in which the duration of elongation stage when arc column is between the moving and static contacts accounts for more than 60%of the total arc burning time.When the pressure is 0.3 MPa,the arc duration of hydrogen,nitrogen and helium at 200 V/1200 A is 1.20 ms,1.42 ms and 1.54 ms,respectively.The peak voltage of hydrogen arc is much higher than that of other two kinds of gas arc,and the arc burning energy is the lowest,which shows that hydrogen has excellent arc extinguishing performance.When the pressure rises from 0.1 MPa to 0.3 MPa,the arc extinguishing performance of the three gases is significantly improved,which is reflected in the reduction of the arc burning time by 17%,the decrease of arc burning energy by 15%,and the acceleration of arc motion.