Measurement of partial discharge in machine winding insulation during short-rise time pulse voltage

The use of power electronics can increase the electrical stress for machine winding insulation. These increased electrical stresses require improvements in quality of the electrical insulation system. A popular method of testing insulation quality is the use of partial discharge measurements. When power electronics are utilized, the harmonics of applied square pulses are present in the electrical insulation. Furthermore, partial discharges due to such voltage distortions cannot be identified and localized with traditional lower frequency measurement techniques. Recent studies include partial discharge measurements for pulse voltage source, but do not completely address problems introduced by the degradation of the machine winding insulation. A method is presented to evaluate partial discharges when square pulse voltage and high temperature is applied causing degradation of machine winding insulation.