Research on electrical aging lifetime model of insulation material under high voltage square impulses for inverter-fed motors

High voltage square impulses from converter can make stator insulation of inverter-fed motors damaged much earlier. There are many differences in insulation aging mechanism between under continuous impulses and under sine waves. In order to test insulation properties under continuous impulses, a new insulation aging test system is used to simulate the aging effect of converter on the winding insulation in the inverter-fed motors. The influences of impulse amplitude, frequency, on insulation lifetime are investigated by using polyimide film. Finally, an insulation electrical aging lifetime model is developed based on the test results.