Abstract

Partial discharge (PD) is a localized dielectric breakdown in high- voltage insulation systems that can lead to catastrophic equipment failure if undetected. Early and accurate detection of PD is critical in ensuring the reliability and longevity of high-voltage equipment such as transformers, GIS (Gas Insulated Switchgear), and cables. Traditional sensors and narrowband antenna systems have limited sensitivity and frequency range, making them less effective for detecting weak PD signals over wide spectra. The narrow operational bandwidth and low sensitivity of conventional PD detection systems impede accurate localization and characterization of PD phenomena, especially under noisy or variable frequency conditions. There is a pressing need for a robust detection mechanism that combines broad frequency response with high detection sensitivity. This study proposes a Broadband Antenna System specifically designed for PD signal acquisition. The system incorporates a log-periodic dipole array (LPDA) antenna integrated with a low-noise amplifier (LNA), coupled to a high-speed digitizer. The LPDA provides ultra-wideband coverage from 50 MHz to 1.5 GHz, enabling the capture of various PD signatures. Finite Element Method (FEM)-based simulations in CST Microwave Studio validate the antenna design. Real-time testing is performed in a controlled high-voltage laboratory environment using a 100 kV test transformer and calibrated PD sources. The proposed antenna system demonstrated a 25% improvement in sensitivity and a 40% increase in detection range compared to standard narrowband antennas. It accurately detected PD pulses with charge magnitudes as low as 5 pC under noisy environments.

Authors

M. Madhusudhan Reddy¹, Thomas Samraj Lawrence²
G Pulla Reddy Engineering College, India¹, University of Louisiana at Lafayette, United States of America²

Keywords

Partial Discharge, Broadband Antenna, High-Voltage Insulation, Log- Periodic Dipole, Sensitivity Enhancement