Research on Low-Profile Directional Flexible Antenna with 3D Coplanar Waveguide for Partial Discharge Detection.

Area of Science:

• Electrical Engineering
• Electromagnetics
• Antenna Theory

Background:

• Partial discharge (PD) detection in Gas-Insulated Switchgear (GIS) cable terminals faces challenges due to metal obstructions and environmental interference affecting traditional flexible antennas.
• Existing flexible antennas struggle with installation and performance in the confined, obstructed environments of GIS cable terminals.

Purpose of the Study:

• To propose and evaluate a novel directional flexible antenna specifically designed for improved PD detection in GIS cable terminals.
• To address the limitations of existing antennas in terms of installation, performance under metal obstruction, and environmental interference.

Main Methods:

• A coplanar waveguide (CPW)-fed monopole antenna with an extended grounding plane was designed for enhanced directional reception.
• The flexible antenna's low-profile (88.5 × 70 × 20 mm) facilitates easy mounting on GIS cable terminals.
• Performance was evaluated using Voltage Standing Wave Ratio (VSWR), impedance stability across bending radii, and effective height measurements.

Main Results:

• The flexible antenna achieved a VSWR < 2 within the 0.541-3 GHz frequency range.
• Stable impedance characteristics were maintained across various bending radii, with an average effective height of 10.79 mm (0.3-1.5 GHz).
• Experimental results on a GIS cable terminal PD platform confirmed minimal impact of bending on detection performance and suitability for detecting PDs despite significant metal obstruction.

Conclusions:

• The proposed directional flexible antenna effectively mitigates challenges posed by metal obstruction and environmental interference in GIS cable terminals.
• The antenna's design ensures robust performance and ease of installation in confined spaces, making it suitable for critical PD monitoring applications.
• The study demonstrates the antenna's capability to cover the detection range of GIS cable terminals and accurately detect partial discharges even with significant signal amplitude reduction due to obstruction.