A new analytical method for the computation of air-gap reactances in 3-phase induction motors

The method presented in the paper includes a generalized analysis of the air-gap MMF based on the equivalent linear current density at the slot opening. A detailed nonlinear magnetic circuit model of the motor cross-section geometry is excited with the fundamental MMF, solved in polar coordinates and the results used to calculate the magnetizing reactance. The contribution of all the air-gap MMF harmonics, apart from the electric fundamental, is added in order to compute the differential leakage reactance. The method has been implemented on computer and has provided better results than some of the classical methods on several test motors.