A Time-domain Characterization Method for UHF Partial Discharge Sensors

The performance of ultra-high frequency (UHF) sensors has a significant impact on the accuracy of UHF partial discharge (PD) detection. In this paper, a method is presented for the time-domain characterization of UHF sensors to provide a comprehensive evaluation of their performance in the time domain. The peak envelope value and the envelope width are adopted in the method as two characterization parameters for predicting the output waveforms of UHF sensors. However, due to the ill-posedness of deconvolution, the measurement of these parameters is highly sensitive to noise. Therefore, an automated optimization scheme is devised based on the multi-parameter filter technique to solve the problem. Two UHF sensors are then investigated using the proposed method. The measured characterization parameters are found to be dependent on the orientation of the sensors, which is discussed from the perspective of sensor geometry. Further, PD experiments are carried out using the same UHF sensors to validate the method. The actual performances of the sensors are in good agreement with their time-domain characterization parameters. The proposed method would be complementary to existing frequency-domain characterization methods and is useful for the comparison of different UHF sensors, especially when their output waveforms are utilized for PD detection.