真空断路器开断小电感电流下多次复燃现象的介质恢复过程分析  

Dielectric Recovery Process of Multiple Re-ignition Phenomena After Small Inductive Current Interruption in Vacuum

作　　者：王枫[1] 王仲奕[2] 郝萌萌 刘志远[4] WANG Fengl;WANG Zhongyi;HAO Mengmeng;LIU Zhiyuan(Department of Electrical and Control Engineering, Xi＇an University of Science ＆ Technology, Xi＇an 710054, China;Department of Electrical Engineering, Xi＇an Jiaotong University, Xi＇an 710049, China;Siemens Electric Drive Equipment Co., Ltd., Shanghai 200137, China;State Key Laboratory of Electric Insulation and Power Equipment, Xi＇an Jiaotong University, Xi＇an 710049, China)

机构地区：[1]西安科技大学电气与控制工程学院,西安710054 [2]西安交通大学电气工程学院,西安710049 [3]西门子电气传动设备有限公司,上海200137 [4]西安交通大学电力设备与电气绝缘国家重点实验室,西安710049

出　　处：《高电压技术》2018年第6期2019-2026,共8页High Voltage Engineering

基　　金：陕西省工业科技攻关项目(2015GY049)~~

摘　　要：真空断路器开断小电感电流产生的多次复燃过电压和介质恢复强度密切相关。因此需建立真空断路器切小感性电流负载的介质恢复微观参数模型,依据此模型得到负载电路参数对真空断路器切小感性电流复燃现象的影响规律。该研究建立了小电感电流真空开断过程的介质恢复鞘层发展模型,得到了介质恢复过程的鞘层发展速度、触头间隙中的电场强度、离子浓度和离子速度等微观参数。以临界击穿场强作为击穿判据,得到了负载电路参数对真空断路器切小感性电流复燃现象的影响规律：负载电容或电感越大,鞘层发展速度变慢,在阴极端产生的最大电场强度越小,因此复燃发生的危险越小,过电压变小;负载端等效电阻的增大会使高频电流幅值减小,从而开断电流减小,鞘层发展速度变慢,最大电场强度降低,因此复燃击穿次数减少。Multiple re-ignition overvoltage is determined by dielectric recovery strength after interruption of small inductive currents in vacuum. We established a micro-physical model for small inductive current interruption in vacuum, with which the influence of load parameters on the re-ignitions can be determined, so as to reveal the sheath development process after interruption of small inductive current in vacuum. The following micro-parameters were determined, including the ion density, ion speed, development of electric field, and potential distribution under various TRVs. A critical electric field strength at the cathode was chosen as a criterion for the re-ignition. The simulation results show the following influence of load parameters on the re-ignitions of small current inductive current interruption in vacuum. A higher load capacitance or a higher load inductance will decrease the sheath development speed and the maximum field strength, which decreases the overvoltage and the risk of re-ignition. The sheath speed and the maximum field strength does not change with the increase of the equivalent resistance, but the load current decreases with the increase of the equivalent resistance. A lower load current reduces sheath velocity, which results in a lower maximum electric field strength. Therefore, it decreases the risk of re-ignition.

关 键 词：真空断路器 小电感电流 多次复燃过电压 介质恢复 鞘层 

分 类 号：TM561.2[电气工程—电器]