我国高压电容器几个关键问题的研究

Research on Several Key Issues of High⁃voltage Capacitors in China

经过近30年的发展,我国高压电容器的设计研发、生产工艺和技术装备都已处于国际先进水平,其产能及年销售量更是多年来雄踞世界第一。然而,在此背景下仍有几个关键问题,如设计场强限值、内部熔丝下限试验电压、极间局部放电等,长期处于争论不休的状态。本文通过对聚丙烯薄膜电气强度试验、电容器内部熔丝的隔离试验和极间局部放电的研究分析得出:不同运行工况及种类的电容器应有不同的场强设计限值,对于高压并联电容器,57kV/mm的场强限值目前来看是适宜的;内部熔丝选取过低的下限电压值对电容器安全可靠运行不利,内部熔丝隔离试验的下限电压值以不低于0.6UNe为宜;电容器绝缘介质的缺陷可以通过极间耐压试验检出,局部放电试验并不能起到提高电容器运行可靠性的作用等结论,供业内技术人员参考,以促进高压电容器的发展。

After nearly 30 years of development,the design,development,production technology and technical facilities of high-voltage capacitors in China have been at the international advanced level,and its production capacity and annual sales have ranked first in the world for years.However,in this context,still several such key issues as the design field strength limit,the lower limit of the internal fuse test voltage and the partial discharge between the capacitor electrodes have been in a state of debate for a long time.In this paper,it is concluded through the research and analysis of the electrical strength test of polypropylene film,the disconnecting test on internal fuses of the capacitor and the partial discharge between the electrodes that capacitors with different operating conditions and types shall have different field strength design limits.And for high-voltage shunt capacitors,the field strength limit of 57 kV/mm is currently appropriate;the selection of the lower voltage limit of the internal fuse is not conducive to the safe and reliable operation of the capacitor,the lower voltage limit of the internal fuse disconnecting testis is suggested not less than 0.6UNe;the defect of the capacitor insulation dielectric can be detected by the voltage test between electrodes,and the partial discharge test can not play a role in improving the operational reliability of the capacitor.The conclusion is used for the reference of technical persons in the industry to promote the development of high-voltage capacitors.