Two Types of Compact UHF Antennas for Partial Discharge Measurement

Partial discharge (PD) online monitoring of transformers by ultra-high-frequency (UHF) approaches has been paid increasingly attention recently. High-qualified UHF antennas are focused on as one key technique. This paper presents two types of compact UHF antennas in small sizes, a Hilbert fractal antenna and a small loop antenna. PD experiments of three typically artificial insulation defects are executed and the both antennas are used for PD measurement. The spectrums of power via frequency of detected PD signals are analyzed and compared. The experimental results show that the Hilbert fractal antenna and small loop antenna are qualified for PD online UHF monitoring.