A Nonlinear Model for the Rapid Prediction of the Magnetic Field in Eccentric Synchronous Reluctance Machines

This article introduces a novel numerical model for the fast characterization of concentric and eccentric synchronous reluctance motors (SynRMs) used in electric vehicles (EVs) applications. Regarding the high impact of the air gap and permeance function on the modeling accuracy, a step variation function is used to consider the flux barriers' effect on the air gap. Then, different types of eccentricity, including static, dynamic, and mixed eccentricity, are modeled. Besides, this model considers the magnetic saturation and the stator slots effect. Numerical computation for the motor inductances is applied to avoid any approximation in the permeance function. The air-gap flux density, electromagnetic torque, and radial force on the rotor are then calculated. This model can be used for the preliminary design of SynRMs to analyze the motor performance in different conditions and accelerate the design procedure. The model is simply adjustable to different configurations. For instance, a four-pole single-layer distributed winding machine with 36-slot and three-flux barriers per pole is investigated. In order to verify the proposed model, the obtained results are compared with finite-element analysis (FEA) and experimental tests. The accuracy of the proposed model for eccentricities up to 30% is 98%, and for higher degrees, it is about 95%.