Abstract：By incorporating the merits of the high torque density, high efficiency, and compact size, the dual-stator low-speed high-torque permanent magnet drive machine (DLHPMDM) is an excellent alternative to the traditional machine in low-speed high-torque applications. For dual-stator machines, the total output torque equals the output torque superposition of inner and outer machines, namely the torque superposition principle of dual-stator machines. This principle can explain the mechanism of reducing the torque ripple of the dual-stator permanent magnet machines. Changing the pole-slot number combination is a crucial method to reduce the torque ripple of machines. However, in analyzing and mitigating torque ripple for the DLHPMDM, considering the inner and outer machines alone needs to be revised and more accurate. More attention should be paid to the superposition reduction effect of inner and outer torque ripple resulting from different phases. The combination number of inner and outer stator slots can affect the torque ripple of the DLHPMDM. Based on the torque superposition principle of dual-stator machines, a design method is proposed to reduce the torque ripple of the DLHPMDM with the inner and outer windings connected in parallel. Generally, the 6th ripple torque accounts for the largest proportion of the torque ripple of permanent magnet machines. Suppose the phase difference between the 6th ripple torque of the inner and outer machines is close to π. In that case, the superposition reduction effect can be achieved, thereby reducing the total torque ripple of the DLHPMDM. When only considering the situation where the fundamental sinusoidal current is passed through the stator windings, the 6th ripple torque is caused by the following two cases. One is the interaction of the fundamental current and the 5th harmonic of the back EMF. The other is the interaction of the fundamental current and the 7th harmonic of the back EMF. The fundamental phases of the inner and outer stator currents are approximately the same. Therefore, when the DLHPMDM is divided into two independent machines for design, the superposition effect of 6th ripple torque of the inner and outer machines can be predicted by the phase relationship of the back-EMFs harmonics. Then, the appropriate winding form combination is determined to reduce the total torque ripple of the DLHPMDM by utilizing the superposition reduction effect. Based on three projects of DLHPMDM with different winding forms installed on the inner stator, the influence of the harmonic phase difference of back EMFs of inner and outer machines on the superposition of the ripple torque is analyzed. By comparing torque performance, the winding form combination of the inner and outer stators is initially selected. Then, considering the influence of harmonic currents from winding harmonics, the torque ripple of DLHPMDM can be effectively reduced (from 8.84% to 5.21%) with a reasonable winding form combination. Finally, a prototype of the DLHPMDM is manufactured and tested. The results are well consistent with the simulated results, which verifies the feasibility of the low torque ripple design method.
刘佶炜, 狄冲, 李仕豪, 鲍晓华. 基于不同绕组形式双定子低速大转矩永磁直驱电机转矩脉动的分析与抑制[J]. 电工技术学报, 2024, 39(12): 3646-3657.
Liu Jiwei, Di Chong, Li Shihao, Bao Xiaohua. Analysis and Mitigation of Torque Ripple of a Dual-Stator Low-Speed High-Torque Permanent Magnet Machine with Different Winding Forms. Transactions of China Electrotechnical Society, 2024, 39(12): 3646-3657.
[1] 黄海林, 李大伟, 曲荣海, 等. 磁齿轮复合永磁电机拓扑及应用综述[J]. 电工技术学报, 2022, 37(6): 1381-1397. Huang Hailin, Li Dawei, Qu Ronghai, et al.A review of magnetic geared machines: topologies and appli- cations[J]. Transactions of China Electrotechnical Society, 2022, 37(6): 1381-1397. [2] 陶大军, 陈阳, 李凌霄, 等. MW级双并列转子低速永磁直驱电机设计方法与性能分析[J]. 电机与控制学报, 2023, 27(9): 82-90. Tao Dajun, Chen Yang, Li Lingxiao, et al.Design method and performance analysis of MW-level dual- parallel rotor low-speed permanent magnet direct- driven motor[J]. Electric Machines and Control, 2023, 27(9): 82-90. [3] 姚钢, 杨浩猛, 周荔丹, 等. 大容量海上风电机组发展现状及关键技术[J]. 电力系统自动化, 2021, 45(21): 33-47. Yao Gang, Yang Haomeng, Zhou Lidan, et al.Deve- lopment status and key technologies of large-capacity offshore wind turbines[J]. Automation of Electric Power Systems, 2021, 45(21): 33-47. [4] Zhao F, Lipo T A, Kwon B.A novel dual-stator axial-flux spoke-type permanent magnet vernier machine for direct-drive applications[J]. IEEE Transactions on Magnetics, 2014, 50(11): 1-4. [5] 鲍晓华, 朱然, 刘佶炜, 等. 基于相位分析的双定子低速大转矩永磁同步电动机转矩脉动研究[J]. 电工技术学报, 2022, 37(22): 5660-5669. Bao Xiaohua, Zhu Ran, Liu Jiwei, et al.Torque Ripple analysis of dual-stator surface mounted low- speed high-torque permanent magnet synchronous motors based on phase analysis[J]. Transactions of China Electrotechnical Society, 2022, 37(22): 5660-5669. [6] Zhang Jiaxu, Zhang Bingyi, Feng Guihong, et al.Design and analysis of a low-speed and high-torque dual-stator permanent magnet motor with inner enhanced torque[J]. IEEE Access, 2020, 8 [7] Liu Jiwei, Bao Xiaohua, Ni Youyuan, et al.A Novel semi-inserted dual-stator low-speed high-torque per- manent magnet drive motor[J]. Journal of Magnetics, 2018, 23(4): 1-6. [8] Niu Shuangxia, Ho S L, Fu W N.A Novel direct-drive dual-structure permanent magnet machine[J]. IEEE Transactions on Magnetics, 2010, 46(6): 2036-2039. [9] Wang Chen, Zhang Zhuoran, Liu Ye, et al.Effect of slot-pole combination on the electromagnetic performance of ironless stator AFPM machine with concentrated windings[J]. IEEE Transactions on Energy Con- version, 2020, 35(2): 1098-1109. [10] Ahsanullah K, Dutta R, Rahman M.Analysis of low-speed IPMMs with distributed and fractional slot concentrated windings for wind energy appli- cations[J]. IEEE Transactions on Magnetics, 2017, 53(11): 1-10. [11] Zhang Zhaoyu, Yu Siyang, Zhang Fengge, et al.Electromagnetic and structural design of a novel low-speed high-torque motor with dual-stator and pm-reluctance rotor[J]. IEEE Transactions on Applied Superconductivity, 2020, 30(4): 1-5. [12] 王玉彬, 程明, 花为, 等. 双定子永磁无刷电机裂比的分析与优化[J]. 中国电机工程学报, 2010, 30(30): 62-67. Wang Yubin, Cheng Ming, Hua Wei, et al.Analysis and optimization of split ratio for double-stator permanent magnet brushless machine[J]. Proceedings of the CSEE, 2010, 30(30): 62-67. [13] Zhang Jiaxu, Zhang Bingyi, Li Dongming, et al.Research on Cogging torque weakening of direct- drive permanent magnetmotor with inner enhance force[J]. IEEJ Transactions on Electrical and Electronic Engineering, 2022, 17: 160-168. [14] Verez G, Barakat G, Amara Y, et al.Impact of pole and slot combination on vibrations and noise of electromagnetic origins in permanent magnet syn- chronous motors[J]. IEEE Transactions on Magnetics, 2015, 53(4): 1-4. [15] Meng Ying, Lu Kaiyuan, Wu Lijian, et al.Reduction methods using canceling effect for cogging torque in dual-stator PM synchronous machines[C]//IEEE Inter- national Electric Machines & Drives Conference, San Diego, CA, USA, 2019, DOI: 101109/IEMDC.2019. 8785112. [16] 鲍晓华, 吴长江, 胡云鹏, 等. 一种优化表插式永磁电机性能的方法[J]. 电工技术学报, 2018, 33(2): 238-244. Bao Xiaohua, Wu Changjiang, Hu Yunpeng, et al.A method for optimizing performance of inset per- manent magnet motor[J]. Transactions of China Electrotechnical Society, 2018, 33(2): 238-244. [17] Liu Jiwei, Di Chong, Li Shihao, et al.Modeling and design of a dual-stator low-speed high-torque permanent magnet drive machine for the ball mill application[J]. IEEJ Transactions on Electrical and Electronic Engineering, 2023, 18(7): 1195-1207.
2024, Vol. 39 
