The development course of dry type current transformer with organic composite insulation was introduced,which is with novel structure and autonomous intellectual property in China.

In view of the Liu-San-Li line which used some overhead line new products such as the insulated conductor, the organosilicon rubber compound insulator,this article analysises and discusses their application and existence some questions in Zhongyuan Oil-field electrical network.

Based on the statistical data of permanent faults due to insulator in Guangdong Province,the comparison of the performance of ceramic,glass and organic synthesis insulators for transmission line on material,process of production,craft control and structure is made,and aging principles of insulator are analyzed.

In recent ten and more years,the composite insulation of PTFE film with silicon oil emerges as a new type of insulation construction used in dry type insulation core in high voltage apparatus,such as wall bushing,current transformer and power cable terminal etc.

The author introduced the research process for the composite insulation sealing of switchgear, presented full experimental data and mentioned the application and prospects of this kind of sealing.

Analysis of flashover on 220-kilovolt lines composite insulator;

The wet-flashover performance of composite insulators in different hydrophobicity and pollution class;

The research on optimization design of 220 kV composite insulator for tension strings;