Development of smart sensor for ultra-high-frequency partial discharge detection

To satisfy the requirements of ultra-high frequency (UHF) partial discharge on-line monitoring, we proposed a novel smart sensor for UHF partial discharge online detection based on stacked multiple-arm Hilbert fractal antenna and level scanning system. Moreover, we improved the traditional Hilbert fractal patch by adding parasitic arm and cascading patch structure, and designed a cascading multiple-arm Hilbert fractal antenna with small size, wide frequency band and high gain, which was used as the antenna of smart sensor. The level scanning module for data collection obtained by level scanning method was used as the data acquisition unit of smart sensor. The needle-plate discharge experiment in air was carried out in laboratory, and the full waveform signal sample method and the smart sensor were used to capture and process the signal simultaneously. The experimental results show that the proposed smart sensor can process the UHF partial discharge signal quickly and directly, output the partial discharge figures with small amount of output data, and lower the cost of hardware and small volume of equipment. The discharge figures obtained by the two methods are nearly same, which proves that the smart sensor can capture and process the partial discharge signal accurately. © 2015, High Voltage Engineering Editorial Department of CEPI. All right reserved.