Development, testing and aging of reference insulation defects for the improvement in partial discharges diagnosis

When partial discharge (PD) activity is detected in a high-voltage (HV) installation, those responsible for their reliable functioning want to know the criticality of the defect or defects with the aim of taking the appropriate corrective actions. In order to assess the criticality of a defect and decide when the red light on the alarm should be activated, a thorough study of the defects evolution over time is required. Although in recent years various companies have acquired valuable knowledge from on-site monitoring applications, the study over time of defects in controlled laboratory test cells can significantly strengthen this knowledge. In the research presented in this paper reproducible test cells, each containing a reference insulation defect, have been developed, tested and aged for the improvement in PD diagnosis. The temporary study of the insulation defects evolution provides valuable information for adopting adequate criteria when evaluating their criticality in the electrical assets. In addition, the information gathered in this research is useful to train the learning processes of artificial intelligence systems, which are developed to perform assisted or automatic PD diagnoses. Finally, it is worth mentioning that as a result of this research the reproducible test cells developed have proved to be useful to perform long lasting laboratory tests with real insulation defects, which results interesting not only for scientific purposes but also for didactic issues.