Investigation into the possibility of using partial discharge measuring equipment to diagnose faults on 3,3 KV machines

Abstract

It is a widely recognised fact that the presence of Partial Discharge activity in machines with an operating voltage exceeding 6,6 kV, enables periodic on-line monitoring of the condition of these machines. Analysis of the discharge activity, can assist maintenance personnel in determining if a winding has become loose, contaminated or if the insulation condition is deteriorating. However, very little information exists regarding PD activity in machines with an operating voltage of 3,3 kV. Although some studies have been conducted, that dealt with measurement techniques and continuous on-line monitoring of 3,3kV machines, very few investigated the discharge levels or failure mechanisms associated with different types of machines. Due to the large amount of critical 3,3 kV machines at Iscor Flat Steel Products, it was deemed necessary to investigate the possibility of applying the same techniques to these machines, in order to determine the condition of the windings. Tests and analysis conducted with a PD Analyser and software manufactured by Iris Power Engineering, indicated that it would be feasible to perform on-line testing of certain 3,3 kV motors.