摘要
在直流真空断路器采取强迫换流方式分断大电流时,由于其电流过零后真空间隙的电弧能量较高,因此会严重影响介质强度的快速恢复。针对此种严酷的分断条件,开展了真空开关串联二极管、真空开关并联RC吸收支路、真空开关串联饱和电抗器几种方案的研究,目的在于增加真空间隙'零休'时间、减小弧后恢复电压上升速度及等离子体浓度。研究结果表明:串联二极管的反向阻断作用能为真空介质恢复提供有利条件,但二极管RC支路的存在会导致电流第1次过零后部分漏电流注入真空间隙,从而影响真空介质的恢复进程;在二极管无RC支路方案下,真空开关电流第2次过零后的电压变化率及幅值都得到了极大的改善;真空开关加装吸收支路能够显著减小其恢复电压变化率;真空开关串联饱和电抗器能在电流过零点附近通过饱和电抗器的退磁作用有效减小其电流变化率。统计试验结果显示,真空开关串联二极管、真空开关并联RC吸收支路、真空开关串联饱和电抗器这3种方案均能在一定程度上提高真空断路器分断的可靠性。
In the environment where the forced commutation method of a DC vacuum circuit breaker is adopted to break the large current,the high arc energy in vacuum gap after current zero crossing seriously affects the rapid recovery of the medium strength.In response to such severe breaking conditions,we studied a series of schemes,such as vacuum switch series diode,vacuum switch parallel RC absorption branch,and a vacuum switch series saturation reactor,ao as to increase the vacuum gap'zero rest'time,and reduce the recovery voltage rise rate and plasma concentration after arc.The results of the research indicate that,the reverse blocking effect of the seriesed diode can provide favorable conditions for the recovery of the vacuum medium,but the existence of the RC branch of the diode will cause some leakage current to be injected into the vacuum gap after the current zero crossing,which will affect the recovery process of the vacuum medium;under the diode-free RC branch scheme,the voltage change rate and amplitude of the vacuum switch are greatly improved after secondary zero crossing of the current;adding an absorption branch to the vacuum switch can significantly reduce the rate of change of the recovery voltage;the vacuum switch series saturable reactor can effectively reduce the current change rate by the demagnetization of the saturable reactor near the current zero crossing.The statistical test results show that the vacuum switch series diode,the vacuum switch parallel RC absorption branch,and vacuum switch series saturation reactor can improve the breaking reliability of vacuum circuit breaker to a certain extent.
作者
李博
彭振东
沙新乐
祝聪
邹顺
杨晨光
LI Bo;PENG Zhendong;SHA Xinle;ZHU Cong;ZOU Shun;YANG Chenguang(Ship Integrated Power System Technology Key Laboratory,Wuhan Institute of Marine Electric Propulsion,Wuhan 430064,China)
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2019年第8期2486-2494,共9页
High Voltage Engineering
关键词
真空开关
电压变化率
电流变化率
介质恢复
分断可靠性
vacuum switch
voltage change rate
current change rate
medium recovery
breaking reliability
