Generation of acoustic phase-resolved partial discharge patterns by utilizing UHF signals

Detection of partial discharges (PD) is of great importance in the monitoring of high voltage devices and their early fault diagnosis. The ultrasonic sensing is one of the PD detection methods proposed in the literature. Normally, the partial discharge signals are mapped onto the voltage waveform to generate the phase resolved partial discharge or PRPD patterns for the fault type recognition. However, the travel time of ultrasonic signals hinders using a similar process in the ultrasonic PD method. In order to avoid this problem and to improve the ultrasonic PD detection by generating corresponding PRPD, this paper presents a novel method that utilizes ultra-high frequency (UHF) and ultrasonic signals of PD, simultaneously. To show the performance of this method, a circuit is built for ultrasonic PD detection first. In the next step, a wideband antenna is utilized, and its signals are compared with the ultrasonic sensor output to compensate for the PD travel time error. Finally, the PRPD patterns are generated and analyzed for five different configurations. The electrical PRPDs are measured for these cases and compared with the acoustic ones. The experimental results demonstrated in this paper prove the potential of the proposed idea to generate acoustic PRPD for the purpose of PD type recognition.