Interpretation of partial discharge patterns

The electrical detection of individual partial discharges from high power electrical plant insulation has proved to be an effective method of monitoring a stress condition which can cause severe degradation and possibly failure of plant insulation. In addition, such measurements can provide a basis for assessing the overall integrity of the insulating system since degradation of the system, irrespective of the particular causative stress, almost always results in partial discharge activity. The nature of the discharge pattern can provide valuable information on the form and extent of degradation and, in some instances, on its location