Experiences with Digital Analysis of Discharges in High Voltage Components

insulation condition he main goal of PD diagnosis is to recognize high voltage insulation problems and to identify the insu- T lation defect causing the discharge: e.g., internal or surface discharges, corona, treeing, etc. This information is vital for estimating the harmfulness of the discharge. Manufacturers of HV equipment, together with producers and distributors of electrical power, have a growing interest in on-site, off-line and on-line analysis of PD in existing HV components. The objective of such analysis is the early recog-nition and location of possible insulation failures in HV equipment. As a result, maintenance actions can be planned to prevent unexpected interruptions in equipment utilization. Furthermore, based on knowledge of the type of discharge and its behavior over time, important information can be ob-,-tained regarding degradation processes. The ability of digital PD analyzers to pro-cess and store specific information concern-ing discharge activity can be used for various purposes: discharge recognition, condition monitoring, etc. [l-1.51. To exploit these pos-sibilities, a specific fingerprint technique has been successfully used in recent years for off-line and on-line PD measurements of HV components [12, 16-18]. In this paper diverse practical examples are discussed of applying advanced digital post-processing for the measurement of par-tial discharges. PD Database for Decision Support The development of a PD database to sup-port the discharge evaluation during periodic off-line inspections of HV components is of great importance. In this paper, based on PD measurements of various HV components, the importance of digital analysis of PD sig