轴向磁通线圈辅助定子励磁双凸极无刷直流电机及转矩脉动抑制方法

Research on Axial Flux Coil Assisted Stator Excitation Brushless Direct Current Motor With Doubly Salient and Torque Ripple Reduction Method

传统永磁无刷直流电机(brushless direct current motor,BLDCM)无法控制永磁磁通量及永磁体固有缺陷,限制了其在许多高科技领域中的应用。该文提出新型双凸极无永磁BLDCM。突破传统结构原理,用轴向线圈磁场辅助径向定子励磁,取消永磁材料特性制约。线圈辅助定子励磁电机更高输出转矩特性可通过提高气隙磁通及电枢绕组的电流实现。用有限元软件进行数值分析并验证其准确性和有效性;基于该电机的特殊结构和电感模型,搭建联合仿真模型,用三相六状态角度导通方式,增加输出转矩,减小转矩脉动;根据辅助励磁线圈调磁特性,进行励磁线圈和电枢绕组混合之励磁电流-转矩控制。实验验证新型结构电机样机及控制方法的可行性和有效性。

Due to the uncontrollable permanent magnet flux and the inherent defects of the permanent magnet, the traditional PMBLDCM suffers the limitation of its application in many high-tech fields. This paper proposed a novel doubly salient brushless DC motor without permanent magnet. To improve the traditional structural principle, assisting radial stator excitation would be done by axial assisted coil field, and the constraints of the permanent magnet material properties was canceled. Higher output torque characteristic of the new motor could be achieved by improving the air-gap flux and the armature winding current. The motor was numerically computed by 3-D FEM, the accuracy and effectiveness was verified; A combined simulation model was built based on the special structure and inductance model of the motor, and this paper adopted a three phase six-state angle conduction mode which could increase the output torque and reduce the torque ripple; Composite excitation current-torque control was proposed based on the adjustable flux characteristic of central assisted excitation coil. The experiments results show that the feasibility and effectiveness of the prototype with a new structure and control method.