Study on Insulator Deterioration Mechanism of ±800kV Transmission Lines and Live Detection Method of Faulty Insulator

Abstract

According to the deterioration characteristic of insulators, leakage current changes in direct proportion to voltage distribution of insulators, however, presence of fault insulator directly affects the insulating property of transmission lines, thus a more accurate, economic and intelligent fault insulator detecting method needs to be studied. This paper designs a detection robot for live detection of faulty insulators of ±800kV ultra-high voltage direct current transmission lines. The detection approach of the device includes shorting out two insulators, collecting detection current generated by a 2500kV power supply of a detection module and leakage current of an insulator string, achieving precise data through an improved algorithm to ensure accuracy of detection results, and developing a prototype to perform simulated experiments. In accordance with experimental data, error of insulation resistance of an insulator detected by the device is within 5% so that whether an insulator of a line in normal operation is a low resistance insulator or zero resistance insulator can be effectively determined, accordingly quality status of the insulator can be judged to achieve the aim of experiments. The equipment is highly practicable and has high practical value in engineering.