Application of an automated PD failure identification system for EMC-assessment strategies of multiple PD defects at HV-insulators

EMC-assessment of field emission of high voltage insulators can be performed using phase-angle-resolved partial discharge diagnosis. However, with conventional PD-detection systems no satisfying statements about multiple PD defects are possible because of the highly dynamic apparent charge values for different discharge phenomena. This measurement problem can be solved by a new approach. For this purpose phase resolved pulse sequence analysis methods are suitable diagnosis tools without using the apparent charge as a dominating influence. A recently developed feature extraction method based on consecutive Δu/Δφ values shows good classification results. The problem of multiple PD defects, which occur at the same time, is a new challenge for PD diagnosis systems. For the investigation two reference databases are generated. With the database, which takes these multiple PD defects into account, the diagnosis system WinTED of the University of Wuppertal is able to identify with high reliability actual measurements made by the University of Dortmund