VHF Magnetic and Electric Sensors for Partial Discharge Measurements in GIS

Abstract

The energy transition towards decarbonization and modernization of the electric network requires the development of new technologies. Offshore windfarms, essential to this transition, rely on Gas-Insulated Systems (GIS) due to their compactness and extended lifespan. Despite the reliability of GIS, the high maintenance costs and severe consequences of power outages leave no room for failure risks. The primary source of failures in GIS is attributed to defects in electric insulation, producing Partial Discharges (PDs) that serve as a tool for defect detection.
The current approach for standardized PD measurements proves impractical for implementation in GIS under operation. Consequently, unconventional methods have been employed with Ultra-High Frequency (UHF) sensors standing out. Despite the notable signal-to-noise ratio of the UHF system, it is still susceptible to interference and does not yield calibrated measurements suitable for comparison with other methods and for assessing insulation degradation. In response to these challenges, this study introduces a Very-High Frequency (VHF) system capable of providing calibrated and reliable measurements....