Calculation and effects of end-ring impedance in cage induction motors

This paper describes a method for calculating the end-ring impedance of a squirrel-cage induction motor using the method of images. The method is verified by using finite-element analysis. A second method is also discussed, although it was found to be too simple to be accurate. The second part of the paper addresses the effect of this impedance variation on the motor performance with particular attention to the starting torque.