Calculation and measurement of dielectric response function in insulation systems of high voltage rotating machines

In this work the possibility of the dielectric response measurement for the evaluation of the actual status of insulation system of high voltage rotating machines are investigated. As test object, model stator bars were used, which are close to real stator bars of high voltage rotating machines. An accelerated ageing procedure was applied to the model bars and the dielectric response was measured in time domain. The dielectric response function was calculated from depolarization current measuring results and the change of this function was evaluated.