Abstract：The permanent magnets (PMs) are the magnetic excitation source in the permanent magnet synchronous motor (PMSM). It could seriously affect the performance of the PMSM. Due to time harmonics of stator current and high-order space harmonics of air gap magnetic field, the loss in permanent magnets is considerable and is easy to cause the partial over-temperature. As a result, the irreversible demagnetization of permanent magnets is occurred with poor cooling condition. This paper discusses a way to reduce the magnet eddy current loss. Herein, a yokeless and segmented armature (YASA) axial flux PMSM is taken as an example, where its parameters are 10 poles, 12 stator segments and 20kW. In order to reduce the magnet eddy current loss, the influences of several factors were studied including the groove depth, groove method and groove number. The expression of magnet eddy current loss and other parameters were calculated respectively. And then the calculated results from the analytic method were compared with those calculated by three dimensional finite element method. Compared with the air gap flux density of the rated load, the reasonable way and number of magnet surface groove were chosen.
王晓远, 齐丹丹, 王辉. 定子无磁轭模块化轴向永磁电机磁极表面开槽分析[J]. 电工技术学报, 2017, 32(16): 145-152.
Wang Xiaoyuan, Qi Dandan, Wang Hui. Analysis on Magnet Surface Groove of Yokeless and Segmented Armature Axial Flux Motor. Transactions of China Electrotechnical Society, 2017, 32(16): 145-152.
[1] Capponi F G, Donato De G, Caricchi F. Recent advances in axial-flux permanent-magenet machine technology[J]. IEEE Transactions on Industry Appli- cations, 2012, 48(6): 2190-2205. [2] Parviainen A, Niemela M, Pyrhonen J. Modeling of axial flux permanent-magnet machines[J]. IEEE Transactions on Industry Applications, 2004, 40(5): 1333-1340. [3] 周凤争, 沈建新, 林瑞光. 从电机设计的角度减少高速永磁电机转子损耗[J]. 浙江大学学报(工学版), 2007, 41(9): 1587-1591. Zhou Fengzheng, Shen Jianxin, Lin Ruiguang. Reduction of rotor loss in high speed permanent magnet motors by design method[J]. Journal of Zhejiang University (Engineering Science), 2007, 41(9): 1587-1591. [4] 陈萍, 唐任远, 佟文明, 等. 高功率密度永磁同步电机永磁体涡流损耗分布规律及其影响[J]. 电工技术学报, 2015, 30(6): 1-9. Chen Ping, Tang Renyuan, Tong Wenming, et al. Permanent magnet eddy current loss and its influence of high power density permanent magnet synchronous motor[J]. Transactions of China Electrotechnical Society, 2015, 30(6): 1-9. [5] Kals A, Howe D, Philip M, et al. Rotor loss in permanent-magnet brushless AC machines[J]. IEEE Transactions on Industry Application, 2000, 36(6): 1612-1618. [6] Hiroaki T, Xia Zheping, Wang Jiabin, et al. Rotor eddy-current loss in permanent magnet brushless machines[J]. IEEE Transactions on Magnetics, 2004, 40(4): 2104-2106. [7] Polinder H, Hoeijmakers M. Eddy-current losses in the segmented surface-mounted magnets of a PM machine[J]. IEEE Proceedings on Electrical Power Application, 1999, 146(3): 261-266. [8] 张凤阁, 杜光辉, 王天煜, 等. 高速电机发展与设计综述[J]. 电工技术学报, 2016, 31(7): 1-18. Zhang Fengge, Du Guanghui, Wang Tianyu, et al. Review on development and design of high speed machines[J]. Transactions of China Electrotechnical Society, 2016, 31(7): 1-18. [9] Woolmer T J, McCulloch M D. Analysis of the yokeless and segmented armature machine[C]//IEEE International Electric Machines & Drives Conference (IEMDC), Antalya, Turkey, 2007: 704-708. [10] Pariviainen A, Niemela M, Pyrhonen J. Modeling of axial flux permanent-magnet machines[J]. IEEE Transactions on Industry Applications, 2004, 40(5): 1333-1340. [11] Huang Y, Ge B, Dong J, et al. 3-D analytical modeling of no-load magnetic field of ironless axial flux permanent magnet machine[J]. IEEE Transa- ctions on Magnetics, 2012, 48(11): 2929-2932. [12] Sung S Y, Jeong J H, Park Y S, et al. Improved analytical modeling of axial flux machine with a double-sided permanent magnet rotor and slotless stator based on an analytical method[J]. IEEE Transactions on Magnetics, 2012, 48(11): 2945-2948. [13] 黄允凯, 周涛. 基于等效磁路法的轴向永磁电机效率优化设计[J]. 电工技术学报, 2015, 30(2): 73-79. Huang Yunkai, Zhou Tao. Efficiency optimization design of axial flux permanent magnet machines using magnetic equivalent circuit[J]. Transactions of China Electrotechnical Society, 2015, 30(2): 73-79. [14] Zhang P, Sizov G Y, He J, et al. Calculation of magnet losses in concentrated-winding permanent magnet synchronous machines using a computati- onally efficient-finite element method[J]. IEEE Transtractions on Industry Applications, 2013, 49(6): 2524-2532. [15] 唐任远, 陈萍, 佟文明, 等. 考虑涡流反作用的永磁体涡流损耗解析计算[J]. 电工技术学报, 2015, 30(24): 1-10. Tang Renyuan, Chen Ping, Tong Wenming, et al. Analytical calculation of eddy current loss accounting for eddy current reaction[J]. Transactions of China Electrotechnical Society, 2015, 30(24): 1-10. [16] 唐守杰, 邹海荣, 王朋, 等. 一种新的降低涡流损耗的磁钢分段方式[J]. 上海电机学院学报, 2015, 18(4): 215-220. Tang Shoujie, Zou Hairong, Wang Peng, et al. Magnet segmentation for reducing eddy current loss[J]. Journal of Shanghai Dianji University, 2015, 18(4): 215-220. [17] 佟文明, 朱晓锋, 贾建国, 等. 时间谐波对永磁同步电机损耗的影响规律[J]. 电工技术学报, 2015, 30(6): 60-69. Tong Wenming, Zhu Xiaofeng, Jia Jianguo, et al. Influence law of additional losses in-duced by time harmonic in permanent magnet synchronous motors[J]. Transactions of China Electrotechnical Society, 2015, 30(6): 60-69. [18] 康慧林, 周理兵, 王晋, 等. 多相分数槽集中绕组表贴式永磁电机谐波电流的确定及其影响[J]. 电工技术学报, 2015, 30(9): 22-29. Kang Huilin, Zhou Libing, Wang Jin, et al. Harmonic currents determination and their impacts on multi- phase fractional-slot concentrated winding surface- mounted permanent magnet machine[J]. Transactions of China Electrotechnical Society, 2015, 30(9): 22-29.
2017, Vol. 32 
