Detection of Corona and Dry-Band Arc Discharges on Nano-Composite Epoxy Insulators Using Rf Sensing

Abstract

Abstract-RF radiation due to corona and dry-band arc discharges have been observed using an antenna. Variations in radiated energy were observed due to change in the distance between two water droplets, the contact angle and the volume of the droplets, and the condition of the insulator surface. Changes in the frequency spectrum within the 800 MHz-900 MHz and 1.25 GHz-1.4 GHz frequency bands have been used to identify the transition from corona discharge to dryband arc discharge. The 800 MHz-900 MHz emission band has also been used to monitor the condition of the insulator. These findings highlight the potential for RF sensing in the identification of partial discharges and insulator condition monitoring.

Surface Tracking on Polymeric Insulators Used in Electrical Transmission Lines

“…This is a situation where the polymeric insulating material makes some tree-like cracks when subjected to high and divergent electrical field stress over a long period of time. These cracks become conducting paths and hence makes the insulator loses its dielectric ability [4].…”

“…When this happens, thermal degradation is limited and hence the formation of continuous carbon tracks is prevented. The ATH fillers and the insulating polymeric materials are blended in the monitored proportions to ensure perfect compatibility that gives out the best dielectric properties [4].…”

Partial Discharge Detection Approach for a Medium Voltage Switchgear System

“…There are many different types of PD in high voltage devices [13][14][15][16]. However, the most common types are corona discharge and dry band discharge.…”

“…The dry band arcing is responsible for a significant amount of current flowing on the surface of insulators enhancing the likelihood of insulator failure [17,18]. Previous measurements used methods such as leakage current and PD detection to characterize the condition of insulators and hence to detect dry band discharges [14,19,20]. The likelihood of corona discharges on insulator surfaces and their transition to dry band arching was also studied using PD [21].…”

“…The spectra in which these discharges emit, are predominantly the 0.8 GHz to 0.9 GHz band, and the 1.25 GHz to 1.4 GHz band [14]. These wide frequency bands indicate a need for a broadband sensor for detection.…”