On-line partial discharge monitoring system for underground MV cables - Part II: Detection and location

Condition based maintenance constitutes a useful tool towards upgrading aging infrastructure in the context of asset management in smart grids. Towards that aim, on-line partial discharge (PD-OL) monitoring systems can provide useful information regarding insulation degradation, that can be used to prevent destructive faults. In this study, a set of novel algorithms is proposed for utilization in such a system. More specifically, an enhanced approach is proposed to denoise partial discharge (PD) associated measurements, by the utilization of the discrete wavelet transform (DWT). Moreover, an overall process is presented for the efficient detection of peaks in denoised signals, and the respective calculation of the PD apparent charge. Furthermore, algorithms are proposed for the detection and location of PDs in practical applications, taking also into account possible pulse reflections, and disregarding the corresponding false positive detections. All proposed methods are rigorously tested, and the respective results are presented.