万航,周凯,刘力.老化中压电缆复合界面的放电特性研究[J].电测与仪表,2020,57(15):14-18. WAN Hang,zhoukai,liuli.Study on discharge characteristics of aging medium voltage cable composite interface[J].Electrical Measurement & Instrumentation,2020,57(15):14-18.
老化中压电缆复合界面的放电特性研究
Study on discharge characteristics of aging medium voltage cable composite interface
In this paper, the discharge characteristics of heat-shrinkable power cable joint of medium voltage cable are studied, and two kinds of cable joint samples are made under different humidity conditions. By comparing the discharge characteristics of dry cable joint’s interface and wet cable joint’s interface, the whole discharge process is divided into three stages, and the different discharge characteristics of these three stages are compared respectively. At last, the samples after breakdown were dissected, and the difference of electric marks was observed between the wet interface and the dry interface after the insulation failure. The main reasons for the difference of discharge characteristics and electric marks are analyzed. It is concluded that the interface cavity is filled with water and the insulation strength is decreased. Although the partial discharge at the initial stage is weakened, the breakdown probability at the later stage is increased The main reason for the different electrical trace characteristics is that the discharge between the dry interface has a cumulative effect on the deterioration of insulation, so the discharge is mainly concentrated in one channel. However, under the action of water, the breakdown of the wet interface occurs at different locations, and the carbonation trace is widely distributed.
