Integrated Ultrasonic and Electrical Sensor for Partial Discharge Detection in Power Transformers

Stable operation of transformers is vital for the security of power grids. And the partial discharges can lead to insulation degradation and potential transformer failures. This paper introduces a built-in acoustic and electrical integrated partial discharge sensor that combines Ultra-High Frequency (UHF) and ultrasonic detection methods. The sensor includes an optical fiber ultrasonic sensing unit and a UHF antenna vibrator, facilitating simultaneous detection of both acoustic and electrical partial discharge signals. Experiments conducted on a 65kV transformer demonstrate the sensor's capability to detect partial discharges consistently across various defect positions, with a lower detection limit of 13.5pC. Results indicate that the integrated sensor effectively addresses the limitations of single-method detection by offering higher sensitivity and accuracy.