Results of the wavelet analysis of the acoustic emission signals generated by partial discharges in insulation oil of various temperature and flow speed

. The paper presents measurement results of the acoustic emission (AE) signals generated by partial discharges (PDs) at insulation oil temperature and flow speed changes. For the AE signals registered, a wavelet analysis based on the use of the continuous (CWT) and discrete (DWT) wavelet transforms was carried out. CWT results are shown as scaling graphs, and DWT results in the form of time runs determined at seven decomposition levels and bar diagrams visualizing the amount of energy transferred by the particular details.