Abstract：In modular cascade machine(MCM) system, unit machine is used as a single module and multiple modules operate in series. Different power demands can be met by adjusting the number of machines. Fractional-slot concentrated windings machine is suitable as a single module of MCM system. In this paper, the rule of slot/pole matching of fractional-slot concentrated windings permanent magnet machine is analyzed. Accordingly, two modular machines with different performance which can meet the requirements of the system capability are designed, and harmonic analysis of magneto-motive force is carried out. The effect of notch width and segmentation of permanent magnet on eddy current loss is analyzed. Eddy current loss is calculated by FEA simulation, and then efficiency map of the MCM system is obtained. Finally, the system is verified by experimental research which is compared with a reference prototype. The results show that the MCM system using fractional-slot concentrated windings permanent magnet machine can reduce the size and weight of system effectively, and improve the torque density.
[1] 韩守亮, 崔淑梅. 一种新型模块化级联电机系统[J]. 电工技术学报, 2013, 28(2): 155-162. Han Shouliang, Cui Shumei. A new modular cascade machine system[J]. Transactions of China Electrotechnical Society, 2013, 28(2): 155-162. [2] Refaie E L A M. Fractional-slot concentrated- windings synchronous permanent magnet machines: opportunities and challenges[J]. IEEE Transactions on Industrial Electronic, 2010, 57(1): 107-121. [3] Bianchi N, Bolognani S, Grezzani G. Design considerations for fractional-slot winding configurations of synchronous machines[J]. IEEE Transactions on Industry Applications, 2006, 42(4): 997-1006. [4] Dorrell D G, Popescu M, Ionel D M. Unbalanced magnetic pull due to asymmetry and low-level static rotor eccentricity in fractional-slot brushless permanent-magnet motors with surface-magnet and consequent-pole rotors[J]. IEEE Transactions on Magnetics, 2010, 46(7): 2675-2685. [5] Hung Vu Xuan, Lahaye D, Polinder H, et al. Influence of slot/pole number combination on performances of permanent magnet machines with concentrated windings for ship application[C]. International Conference on Electrical Machines and Systems (ICEMS), 2011: 1-6. [6] 谭建成. 三相无刷直流电动机分数槽集中绕组槽极数组合规律研究[J]. 微电机, 2007, 40(12): 72-77, 86. Tan Jiancheng. Investigation on slot/pole number combinations for 3-phase BLDCM with concentrated windings[J]. Micromotors, 2007, 40(12): 72-77, 86. [7] 陈益广, 潘玉玲, 贺鑫. 永磁同步电机分数槽集中绕组磁动势[J]. 电工技术学报, 2010, 25(10): 30-36. Chen Yiguang, Pan Yuling, He Xin. Magnetomotive force in permanent magnet synchronous machine with concentrated fractional-slot winding[J]. Transactions of China Electrotechnical Society, 2010, 25(10): 30-36. [8] 彭兵, 王成元, 夏加宽, 等. 磁动势法五相永磁力矩电机转矩分析[J]. 中国电机工程学报, 2012, 32(21): 105-111. Peng Bing, Wang Chengyuan, Xia Jiakuan, et al. Torque analysis of five-phase permanent magnet torque motors based on magnetic motive force[J]. Proceedings of the CSEE, 2012, 32(21): 105-111. [9] Seok Hee Han, Thomas M Jahns, Zhu Z Q. Analysis of rotor core eddy-current losses in interior permanent-magnet synchronous machines[J]. IEEE Transactions on Industry Applications, 2010, 46(1): 196-205. [10] Deng F. Commutation-caused eddy-current losses in permanent-magnet brushless DC motors[J]. IEEE Transactions on Magnetics, 1997, 33(5): 4310-4318. [11] Yamazaki K. Torque and efficiency calculation of an interior permanent-magnet motor considering harmonic iron losses of both the stator and rotor[J]. IEEE Transactions on Magnetics, 2003, 39(3): 1460-1463. [12] Yamazaki K, Kanou Y. Rotor loss analysis of interior permanent-magnet motors using combination of 2-D and 3-D finite element method[J]. IEEE Transactions on Magnetics, 2009, 45(3): 1772-1775. [13] Chen Y S, Zhu Z Q, Howe D. Vibration of PM brushless machines having a fractional number of slots per pole[J]. IEEE Transactions on Magnetics, 2006, 42(10): 3395-3397. [14] Toda H, Xia Z, Wang J, et al. Rotor eddy-current loss in permanent magnet brushless machines[J]. IEEE Transactions on Magnetics, 2004, 40(4): 2104-2106. [15] Polinder H, Hoeijmakers M J, Scuotto M. Eddy- current losses in the solid back-iron of PM machines for different concentrated fractional pitch windings[C]. IEEE International Electric Machines & Drives Conference(IEMDC), 2007: 652-657. [16] Atallah K, Howe D. Rotor loss in permanent-magnet brushless AC machines[J]. IEEE Transactions on Industry Applications, 2000, 36(6): 1612-1618.
2013, Vol. 28 
