Experimental study on sensing characteristics of PD sensor based on shield ring of GIS basin insulators

Partial discharge (PD) detection is an important technique of GIS condition monitoring and evaluating. Due to factors such as cost, the number of ultra-high frequency (UHF) sensors employed on site is often limited, resulting in detection blind spots. The PD sensing technology based on the internal shield ring of basin insulators can effectively solve the problem of insufficient detection points. In this paper, a 1000-kV GIS test platform is established, the frequency response characteristics, pulse response characteristics, and sensing directionality of insulator PD sensor and traditional inner UHF sensor are studied and compared. The results show that, within 300 MHz~1500 MHz, the return loss of the insulator sensor is higher than that of the inner UHF sensor, while the insertion loss is lower than that of the inner sensor. The insulator sensor has better signal sensing characteristics in the frequency range of 300 MHz to 1500 MHz. The detection sensitivity of the inner sensor will be significantly affected by the installation angle of the sensor, while the insulator sensor has weak sensing directionality in GIS PD detection, which is conducive to practical application. The results of this paper lay the foundation for the on-site application of PD sensing technology based on the shield ring of basin insulators.