3D Finite Element Analysis of a Hybrid Stepper Motor

Abstract: Hybrid stepper motors are being applied to more and more industrial regionsdue to their low cost compared with servo motors and prominent performance.Many industrial applications require accurate and eective methods for predictinga motor’s performance at the design stage. The geometry of the motorsis complicated and the magnetic saturation eect is also serious, giving riseto the diculty of understanding the transient behavior of the motors. Furthermore,the drive circuit and control algorithm are more sophisticated thanthose of traditional AC or DC motors. Lastly, the losses of the motors createthe rising of temperature, while the thermal eect and dynamic performanceaect each other.All these factors can be solved by simulating a hybrid stepper motor witha model combining the eect of electromagnetic field, control algorithm, andmotor loss together. In this thesis, a three-dimension (3D) finite elementmodel is developed in the software Maxwell for studying motor characteristics.The electromagnetic field is analyzed in a static state. The simulatedback electromagnetic force is verified by experiments. The feasibility of fullstepcontrol algorithm is analyzed. The vector control algorithm is applied tothe model through co-simulation of Simulink and Maxwell in Simplorer. The3D model is proved to be unrealistic for co-simulation. In the end, this thesissummarizes the modeling experience and gives recommendations on thetransient simulation of the motor.