Improved Partial Discharge Signals Analysis Using Discrete Wavelet Transform

It is well known that during the operating life of high voltage (HV) equipments, the insulating materials of which they consist are subjected to structural changes, which can lead to the degradation of insulation properties. Early detection of these changes in insulation allows by adequate maintenance the extension of the life of HV equipment. By partial discharge (PD) detection, it is possible to determine how damaging these changes are to the insulation of HV equipment. Thus, this article presents the phenomena and steps by which measurements for PD detection can be performed. It also presents the analysis and filtering using Discrete Wavelet Transform (DWT) features, which are superior to conventional filtering methods, for signals describing the main characteristics occurring in PD. In addition, experimental tests performed on some of equipments and measurement schemes suitable for PD determination and analysis are also presented.