Digital signal processing methods for interference recognition in partial discharge measurement-a comparison

Partial discharge (PD) testing is well known for the examination of the insulation characteristics of high voltage equipment. For low voltage components like relays, optocouples etc. PD testing is also of growing interest to ensure the quality of the products and the manufacturing process. The application for pieces testing of mass products in an industrial environment implies automatic interference recognition and short test cycle times. These features can be obtained using digital signal processing methods. In this paper, three different methods, the tolerance band method, the correlation factor analysis and the cross correlation analysis are introduced and their application to automatic PD testing is shown and discussed.