ASSESSMENT OF DIELECTRIC DEGRADATION BY ULTRAWIDE-BAND PD DETECTION

Partial discharges (PD) and the way they affect insulation quality has for decades been a rewarding subject for many researchers. And still the attention given to this field is considerable, partly because of the quest to predict the residual life of HV components. There are two topics that are of particular interest to the workers in the field of PD. One is the impact of a wide variety of statistical tools on the interpretation of discharge data obtained with standard PD detection apparatus according to IEC270. Pattern recognition techniques applied to phase distributions of PD lead to valuable results and are addressed by other authors in this issue. The other topic is the study of discharge-induced degradation processes by looking into the physics of the discharge process. This can be done by different means but a valuable technique, at least for the laboratory, is the use of ultra-wide band PD detection systems. This paper is a mix of a short review on the progression in the understanding of deterioration by internal PD obtained with such systems and of results recently obtained by the author.