摘要
基于换流原理的机械式高压直流真空断路器,是高压直流系统短路开断的有效方式之一,电弧熄灭后断口间介质恢复强度能否耐受恢复电压是决定其开断性能的关键,因此换流时间与最小安全开距的配合成为其设计的重要参考依据。该文利用直流开断实验平台,实验研究了高压直流真空开断系统样机在不同换流时刻、开断电流幅值、换流频率、换流电流与开断电流的幅值比(换流比)下的换流时间和最小安全开距。结果表明:换流时刻选择过早会导致电弧因开距不足而重燃,在实验条件下,换流频率3kHz,开断5kA直流电流,最小安全开距约为0.60mm;随着开断电流幅值的增加,最小安全开距近似线性增大;随着换流频率或换流比的增大,换流时间均将明显减小,对最小安全开距的要求也随着断口恢复电压的增加而更高。
Mechanical high voltage direct current(HVDC)vacuum circuit breaker based on commutation principle is one of the solutions for short circuit failure interruption in HVDC system.After arc extinction,whether the medium recovery strength can withstand the recovery voltage is the key factor influencing the interrupting performance.Therefore,the commutation time and minimum safe stroke become important references for the design of mechanical HVDC vacuum circuit breaker.In this paper,at different initial moments of commutation time,interrupting current amplitudes,commutation frequencies and amplitude ratios of the commutation current to the interrupting current(commutation ratio),the commutation time and minimum safe stroke of DC vacuum circuit breaker were tested by a DC test circuit.The experimental results show that,if the initial moment of commutation time is too early,it may lead to insufficient gap distance between contacts and cause arc reigniting.When the commutation frequency is 3kHz and the interrupting current is 5kA,the minimum safe stroke is about 0.60mm.With the increase of the interrupting current amplitude,the minimum safe stroke increases approximately linearly.The higher the commutation frequency and the commutation ratio,the smaller the commutation time is.The minimum safe stroke is more demanding as the recovery voltage increases.
作者
张梓莹
梁德世
蔡淼中
邹积岩
刘芮彤
Zhang Ziying;Liang Deshi;Cai Miaozhong;Zou Jiyan;Liu Ruitong(School of Electrical Engineering Dalian University of Technology,Dalian 116024 China;State Grid Liaoning Electric Power Research Institute,Shenyang 110006 China)
出处
《电工技术学报》
EI
CSCD
北大核心
2020年第12期2554-2561,共8页
Transactions of China Electrotechnical Society
基金
国家电网公司2017年总部科技资助项目(0711-160TL14711127)。
关键词
机械式高压直流真空断路器
换流时间
换流比
最小安全开距
Mechanical HVDC vacuum circuit breaker
commutation time
commutation ratio
minimum safe stroke
