Flexible Planar Monopole Built-in GIS PD Sensor Based on Meandering Technology.

Area of Science:

• Electrical Engineering
• Electromagnetics
• Sensor Technology

Background:

• Existing rigid Ultra-High Frequency (UHF) sensors for partial discharge (PD) in gas-insulated switchgears (GIS) suffer from low space utilization and disrupt internal electric field distribution.
• Flexible wearable antenna concepts are adapted to develop novel sensors for GIS PD detection.

Purpose of the Study:

• To introduce and investigate flexible planar monopole antennas as sensors for PD detection in GIS.
• To optimize antenna performance using meandering techniques for improved VSWR in the UHF band.
• To evaluate the antenna's effectiveness and signal-to-noise ratio (SNR) under bending conditions within a GIS environment.

Main Methods:

• Designed and simulated a flexible planar monopole antenna, optimizing its Ultra-High Frequency (UHF) band performance with meandering.
• Fabricated the antenna with dimensions 142 mm × 195 mm × 0.28 mm.
• Tested the antenna's Voltage Standing Wave Ratio (VSWR) under various bending radii (0 mm, 200 mm, 400 mm) and evaluated its performance on a 220 kV GIS PD detection platform.

Main Results:

• The improved monopole antenna achieved a VSWR ≤2 in specific UHF bands (570-830 MHz, 1.38-1.8 GHz, 2.2-2.76 GHz) across different bending radii.
• The antenna maintained a VSWR ≤5 across a broader frequency range (450 MHz-3 GHz).
• Physical tests demonstrated the antenna's capability to detect PD signals with a high SNR even after bending deformation.

Conclusions:

• Flexible planar monopole antennas are a viable solution for PD detection in GIS, overcoming limitations of rigid sensors.
• The meandering technique effectively optimizes antenna performance for UHF PD detection in bent configurations.
• The developed flexible antenna technology offers a promising approach for enhanced monitoring and maintenance of GIS equipment.