并联电容对真空灭弧室内部电位分布的改善作用  

The Improving Effect of Parallel Capacitors on the Internal Potential Distribution of Vacuum Interrupters

作　　者：李元钊 丁健刚 刘志远[1] 耿英三[1] 王建华[1] Li Yuanzhao;Ding Jiangang;Liu Zhiyuan;Geng Yingsan;Wang Jianhua(State Key Laboratory of Electrical Insulation and Power Equipment Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]电工材料电气绝缘全国重点实验室(西安交通大学),西安710049

出　　处：《电工技术学报》2025年第2期610-624,共15页Transactions of China Electrotechnical Society

基　　金：国家重点研发计划资助项目(2022YFB2403700)。

摘　　要：真空灭弧室的绝缘水平是影响其性能和可靠性的一个关键因素。现有研究发现,真空灭弧室放入接地金属外壳内,受对地杂散电容的影响,屏蔽罩电位会出现偏移现象,导致灭弧室绝缘水平下降。针对此问题,该文通过建立真空灭弧室等效电路模型,研究了通过并联电容调整屏蔽罩电位对灭弧室内部电位分布的改善作用,并通过实验测量了真空灭弧室屏蔽罩悬浮电位,验证了并联电容方法的改善作用。研究结果表明,真空灭弧室的杂散电容约为十几pF量级,通过为灭弧室并联百pF量级的电容,可以有效地改善其内部的电位偏移现象。实验中所测量的真空灭弧室在自然状态下,其主屏蔽罩电位约为34%总电压,对该灭弧室并联500 pF电容,可将其主屏蔽罩电位调整至49%总电压。此外,针对具有多级悬浮屏蔽罩结构的真空灭弧室,提出并对比了两种电容并联方案的差异,得到只调整主屏蔽罩电位的电容并联方式是更为理想的选择。Insulation is a crucial factor in the performance and reliability of vacuum interrupters.Previous research has found that placing vacuum interrupters in grounded metal enclosures can cause potential offsets in shields and reduce the insulation performance of vacuum interrupters.This study establishes an equivalent circuit model to improve internal potential distribution by adjusting shield potential with parallel capacitors.As a result,paralleling capacitors on the order of hundreds of picofarads can effectively improve the potential shift of the interrupter.In experiments,the measured main shielding potential of the vacuum interrupter is about 34%of the total voltage in its natural state.By paralleling 500 pF capacitors,the potential of the main shield can be improved to 49%.Two capacitor parallel schemes are proposed and compared with multi-stage floating shield structures.The paper investigates the influence of ground position variations on the internal potential and electric field distribution of the vacuum interrupter.The stray capacitance parameters of the vacuum interrupter are extracted,and an equivalent circuit model of the vacuum interrupter is established.Secondly,a method is proposed to adjust the potential of the shield in the vacuum interrupter using parallel capacitors.Based on the equivalent circuit model of the vacuum interrupter,the influence of parallel capacitors on the internal potential and electric field distribution of the vacuum interrupter is studied.Experiments are designed and conducted to measure the floating potential of the shield in the vacuum interrupter.The differences in the shield potential between parallel and non-parallel capacitors are compared,verifying the effectiveness of the proposed method.Finally,for high voltage level vacuum interrupters with multi-stage floating shield structures,differential effects of different parallel configurations on the internal potential distribution improvement in the vacuum interrupter are studied.The following conclusions can be drawn.(1)B

关 键 词：真空灭弧室 屏蔽罩 悬浮电位 并联电容 非接触式测量 

分 类 号：TM561.2[电气工程—电器]