The inter-winding insulation and tendency of nominal voltage increase in high voltage asynchronous machines

This paper suggests an increase of rated voltage of electrical machines as means to improve the efficiency of use of electrical energy. A solution is to raise the high voltage asynchronous machines voltage to the level of the high voltage distribution network supply voltage, thus enabling a direct connection into the network, as the case with low voltage motors. In this paper we have investigated a large number of samples to find out a weak points in inter winding insulation along the high voltage asynchronous machines coil. The experiments were made on the lacquer-glass-glass-lacquer conductor insulation. We have determined the location of weak points and the level of the breakdown voltage.