The Bandwidth Verification of VHF Antenna and Apply for Partial Discharge Measurement

Abstract

This research explains the bandwidth verification and application of the VHF antenna for partial discharge measurement. Three different VHF antennas were used for the experiment. In the research, the measuring bandwidth of such antennas was evaluated using a network analyzer. The antenna properties such as return loss and voltage standing wave ratio were analyzed. Then, the partial discharge in the air was simulated using the surface discharge model. The physical phenomena of PD occur like pulse current transients and electromagnetic waves. The pulse current transients were detected using a coupling capacitor and HFCT sensor, while the electromagnetic wave was detected using a VHF antenna. five test positions of the VHF antenna were designated for partial discharge measurements namely 1, 2, 3, 4, and 5 meters away from the partial discharge source. The PRPD pattern, PD magnitude, and waveform obtained from the VHF antenna were compared with coupling capacitors and HFCT sensors and presented in this paper. It is found that the VHF antenna, which has higher return loss and lower voltage standing wave ratio, provides high performance to detect the electromagnetic wave of partial discharge.