Advanced technology of stator winding insulation system for HV motors

To improve the reliability and the productivity of insulated windings for high voltage motors, we have developed the refined vacuum pressure impregnation (VPI) system. Higher thermal resistance and better impregnability have been achieved by new mica paper with small amounts of milled glass fibers in it. In this paper, we described the impregnability, the voltage endurance and the thermal resistance of our new VPI.