Design and optimization of asymmetric eccentric circular-shaped barriers for synchronous reluctance machines
摘要
In this paper, an asymmetric rotor structure using eccentric circles to form flux barriers is proposed to reduce the torque ripple of the synchronous reluctance machine (SynRM). With eccentric circular-shaped flux barriers, more optimization parameters can be taken into account for the rotor structure than with concentric circular-shaped flux barriers, offering a wider range of possibilities for improving the torque performance of SynRMs. Besides the thickness and end position, the end width is taken into account for the optimal design of the eccentric circular-shaped flux barrier to enhance the torque performance of SynRMs. The validity of the proposed eccentric circular-shaped flux barrier in reducing torque ripple is verified by analyzing the performance of the machine with two rotor structures under different operating conditions. Moreover, the eccentric circular-shaped flux barrier on the d-axis side is offset to form an asymmetric rotor structure, resulting in a further reduction in the machine torque ripple. In comparison with the rotor structure with concentric circular flux barriers, the proposed rotor structure decreases the torque ripple of a SynRM by 41.86% at the rated current with different degrees of torque harmonics. Under different currents and current angles, the torque ripple of a SynRM can have been substantially decreased while maintaining the output torque.