Automatic detection and elimination of periodic pulse shaped interferences in partial discharge measurements

The interferences present in partial discharge (PD) measurement can be classified as narrow-band and broad-band, the latter being pulsed shaped. The pulse shaped interferences can be periodic or random with respect to power frequency, the former being very common and strong. The paper describes an algorithm for automatic detection and elimination of periodic pulse shaped interferences in PD measurements. The algorithm is developed on lines similar to that used in decomposing an electromyogram (EMG) into its individual motor unit potentials and is verified with practical and simulated PD measurements. In addition to interference pulse rejection, the algorithm can be used to process data from a digital PD detector for overcoming integration errors, obtaining pulse to pulse time interval histograms and distinguishing different PD pulses based on their waveshape