Study on Estimation Method of Actual Discharge Quantity Inferred from Ultra-High Frequency Signals in Digital Modeling of GIS

Detection of partial discharge (PD) in gas-insulated switchgear (GIS) is an effective method for state assessment and fault diagnosis. Estimating the actual discharge quantity is an important aspect of PD detection. The commonly used measurement method is the pulse current method, but it is not applicable for online use. To address this issue, this paper proposes a method for estimating the maximum actual discharge quantity based on the second integral value of ultra-high frequency (UHF) signals over time. Firstly, the study establishes a digital model of GIS, including the model of PD sources and ultra-high frequency sensors. The rationality of estimating the actual discharge quantity using the integral value of ultra-high frequency signals over time is verified through simulation data. Finally, by comparing and analyzing the results with high-voltage test data, the factors affecting the accuracy of estimating the actual discharge quantity are identified. The research findings provide a solution for analyzing the intrinsic discharge quantity within GIS based on digital modeling.