New Approach to Cogging Torque Simulation Using Numerical Functions

The paper presents a new approach for simulation of the cogging torque in a PM machine. The method exploits the numerical functions for modeling the magnetic circuit of the machine. The paper introduces two improved functions to model the permanent magnets and the air gap permeance, aiming to compute the cogging torque in the PM machine. The first function states the MMF drop on the machine air gap with respect to the angular position. The other function, named permeance function, models the air gap permeance accurately, taking into account the stator saliency due to the teeth. The described procedure has been tested on a prototype PM machine