Analytical Method to Consider the Slot Opening Effects in Nonlinear Magnetic Equivalent Circuits of Induction Machines

A magnetic equivalent circuit with a focus on the air-gap is presented. The model takes the slot openings and its effects into account by applying magnetic permeance waves. While the amount of permeance elements in the airgap is significantly increased, the number of nodes, respectively equations and therefore the calculation time compared to a basic model stays the same. Nevertheless, the proposed method makes it possible to determine the magnetic field in the air-gap with a high accuracy, as verified by three different motors.