Experimental and Finite Element Analysis of Solid Rotor End Effects

The effect of the rotor axial length on the medium- speed solid-rotor induction motor performance characteristics is studied. The measured electromagnetic torque of the solid-rotor induction motor is compared to the results obtained from the finite element calculations. According to laboratory measurements the effect of the solid iron rotor "end ring" length on the electromagnetic torque can be as high as 8 per cent in a case of 180 kW, 10200 rpm machine. Thus, three-dimensionality of a solid-rotor should be taken into account in two-dimensional finite element calculations. In this paper it is shown that the three- dimensionality can be taken into account with tolerable accuracy utilizing a corrective end-factor.