高速列车过分相段下真空断路器的电寿命研究

针对高速列车真空断路器(VCB)在列车运行中处于频繁开断的状态,开断过程中电弧反复烧蚀触头产生尖端、毛刺、金属蒸汽,扩散的金属蒸汽又使灭弧室真空度降低,首次提出了通过测量VCB在分断不同次数正常电流下接触电阻表征其电寿命的试验方法,并得到了不同分断次数下耐受冲击电压和工频工作电压的特性.研究表明:VCB初期接触电阻随分断次数增加而增加,之后接触电阻基本保持不变；在VCB使用初期瞬态恢复电压不能导致电弧重燃,长期工作后可能导致电弧多次重燃,但即使长期工作后工频工作电压仍不能击穿灭弧室.

Electric Life of Vacuum Circuit Breaker Considering High-speed Trains Passing Neutral Sections

For the vacuum circuit breaker(VCB) breaking frequently in high-speed railway,contacts were repeatedly corroded,and tips,coarsenesses and reduction of vacuum degree of diffusing metal vapor were caused by arc during breaking.The experimental program was proposed of characterizing VCB electric life by measuring contact resistance of normal current under different breaking number.Meanwhile,the characteristics of withstanding impulse voltage and frequency voltage under different breaking number were obtained.Studies have shown that the contact resistance was initially increasing with the increase of breaking number,and after that,contact resistance was unchanged;in the initial testing period,the transient recovery voltage could not cause reignition of arc,but multiple reignitions of arc would happen possibly with working in a long term,although the gas of interrupter could not be breakdown by workingfrequency voltage.