# Simulation Study on Anti-Interference Performance Degradation of GIS UHF Sensors Based on Substation White Noise Reconstruction

## TL;DR

This paper studies how antenna corrosion in UHF sensors affects their performance in detecting partial discharges in GIS systems, using simulations to quantify signal degradation and noise increase.

## Contribution

A novel noise reconstruction method based on sensor reciprocity is proposed to simulate on-site white noise for sensor calibration in GIS environments.

## Key findings

- Antenna corrosion causes a 55.27% reduction in PD signal power and a 64.11% increase in noise power.
- The signal-to-noise ratio (SNR) degrades from −9.70 dB to −15.34 dB with visible waveform distortion.
- Sensor performance parameters like S11 and VSWR are significantly impacted by antenna corrosion.

## Abstract

The ultra-high frequency (UHF)-based partial discharge (PD) detection technology for gas-insulated switchgear (GIS) has achieved large-scale applications due to its high sensitivity and real-time monitoring capabilities. However, long-term service-induced antenna corrosion in UHF sensors may lead to degraded reception characteristics. To ensure the credibility of monitoring data, on-site sensor calibration under ambient noise conditions is required. This study first analyzes the time–frequency domain characteristics of white noise received by UHF sensors in GIS environments. Leveraging the transceiver reciprocity principle of sensors, a noise reconstruction method based on external sensors is proposed to simulate on-site white noise. Subsequently, CST simulation models are established for both standard and degraded sensors, quantifying the impact of factors like antenna corrosion on performance parameters such as echo impedance S11 and voltage standing wave ratio (VSWR). Finally, the two sensor models are coupled into GIS handholes for comparative simulation analysis. Results show that antenna corrosion causes resonant frequency shifts in sensors, reducing PD signal power by 55.27% and increasing noise power by 64.11%. The signal-to-noise ratio (SNR) decreases from −9.70 dB to −15.34 dB, with evident waveform distortion in the double-exponential PD pulses. These conclusions provide theoretical references for on-site UHF sensor calibration in noisy environments.