Partial discharge pulse propagation in shielded power cable and implications for detection sensitivity

A new approach has been developed in predicting the propagation characteristics of partial discharge (PD) pulses of arbitrary shape and the partial discharge detection sensitivity that can be achieved through PD pulse waveforms. There are two typical waveforms used for the application of this approach, namely, a narrow Gaussian pulse and a slower, asymmetric pulse based on the assumption that the attenuation constant of the cable is proportional to frequency. For both narrow Gaussian and broader asymmetric PD pulses, the PD detection sensitivity under relatively noisy field conditions is in the range of 30 to 100 pC at 1000m depending on the method of PD detection and based on the background voltage spectral noise density. The PD detection sensitivity achieved in the field is very sensitive to ambient noise conditions caused by scales of PD detections limit is parallel with the voltage spectral noise density.