Accelerated aging of high voltage stator bars using a power electronic converter

The use of computer-aided partial discharge detectors has become an increasingly useful tool in the application of electric machine insulation condition monitoring. The problem that exists is the lack of field and laboratory data associated with the faults that the condition monitoring aims to find. A stator winding aging bed has been constructed to allow the monitoring of the growth of induced faults, for comparison with field measurements. The use of a low emission, variable frequency power electronic converter, along with a computer-based discharge analyser, has allowed the study of supply frequency dependence of partial discharge activity along with the monitoring of fault initiation and development. The layout of the aging bed is discussed along with the operating performance of the variable frequency converter and partial discharge results gathered.