Application of digital signal processing techniques for noise suppression in partial discharge measurements

Interference is probably the biggest problem for partial discharge (PD) measurements on high voltage equipment at industrial sites. Interference can enter the measurement circuit from various origins and behaviour in complicated ways. Techniques for suppressing a certain kind of interference should be developed according to its characteristics. It has been found that digital signal processing techniques are promising in alleviating the interference problem. Some of these techniques are briefly discussed including signal alignments by cross correlation, separation of PDs from different discharge sources, and adaptive filtering using a calibration pulse as a reference