Partial discharges. XII. Partial discharge detection in rotating electrical machines

A synthetic noise suppressing algorithm for partial discharge signals of generators

“…Through many experiments and analyses, we found another important property that as the effect of the adjacent phase induction noise increases, the average number of samples in the phase interval of the adjacent phase induction noise is on the rise. Using these properties we make a criterion for deciding the adjacent phase induction noise like (1). Specifically, if the number of extracted samples per degree is equal or greater than the criterion, those samples are estimated to be the adjacent phase induction noise and eliminated.…”

“…Since the winding insulation of generators is continuously exposed to a combination of thermal, electrical, mechanical, and environmental stresses during their operation, the insulation material deteriorates gradually over time. While this deterioration in progress, PD signals can be measured as a direct cause or symptom of winding insulation failure of electrical machines [1], [2]. Analysis of PD signals, therefore, is recognized as a key technique for monitoring the condition of the winding insulation of generators and requires high precision.…”

Entwicklungen und Nachweisuntersuchungen von Diagnosemethoden für Wasserkraftgeneratoren

“…Die Teilentladungsdiagnose ist eines der meistversprechenden Werkzeuge fª die Beurteilung von Isoliersystemen von St~inderwicklungen [6]. anzuwenden.…”

Prospective method for partial discharge detection in large AC machines using magnetic sensors in low electric field zones

“…Several machines are equipped of specific sensors placed inside the slots or in the end-winding connections able to localise PD activity in the stator winding [1] [2] [5]. For these machines, the sensors are near the stator bars and electrical insulation problems or the sensors types must be solved.…”