The effect of pulsed voltages on dielectric material properties

The problem of premature failure of rotating machines fed by inverters appe ars to be of crucial importance. Understanding of the phenomena caused by t his new type of supply on the stator insulation of motors provides enhanced reliability of the inverter/motor set. After identifying the stresses crea ted by this type of device, a study of aging of the materials used as model s, and subjected to similar stresses, is undertaken. For the voltage, rise time and frequency under study, the intrinsic part of the aging is studied. The results are presented and discussed according to the nature of the int eraction existing between the electrical stress and the material properties .