Analysis of wideband EM waves emitted from partial discharge using the constrained interpolation profile (CIP) method and the in-place fast haar wavelet transform

Measurement of partial discharge (PD) has been used to assess the condition of insulation material used in electric power equipment. Analysis on the electromagnetic (EM) waves emitted from PD is useful from the viewpoint of noncontact diagnosis because PD emits wideband EM waves. The constrained interpolation profile method (CIP) is used to visualize the wideband EM waves emitted from PD for understanding the physical mechanism. The wideband EM waves are analyzed by using the in-place fast Haar wavelet transform(IP-FHWT), which can show the discrete time- frequency components. The PD is numerically obtained by the total amount of charge and the rise time. Numerical results show that the proposed method based on the CIP and the IP-FHWT is useful for analyzing the relationship between the PD current and the EM waves.