Abstract：In this paper, permanent magnet (PM) magnetization model of a variable flux PM memory motor (VFMM) under continuous de- and remagnetization is built, and recoil line equation under demagnetization and local hysteresis curve equation under remagnetization are given. Flux density variation in PM and flux distributions of VFMM under the role of different stator d-axis currents are analyzed by finite element (FE) method incorporating with the magnetization model. No-load air-gap flux density waveforms, phase flux-linkages, phase back EMFs and air-gap flux per pole are calculated at different PM magnetization states. The FE analysis flowchart of PM continuous de and remagnetization is given in this paper. A prototype machine is designed and tested. Good agreement between calculated and measured results is achieved. It shows that the continuous demagnetization of VFMM is approximately linear, but the re-magnetization performance is nonlinear. Compared with the PM demagnetization, the remagnetization of PM is more difficult. About 4 times the full de-magnetizing current is required to achieve the full remagnetization of PM.
[1] Xu L Y, Ye L R, Li Z. A new design concept of permanent magnet machine for flux weakening operation[J]. IEEE Transaction on Industry Application, 1995, 31(2): 373-378. [2] Jahns T M. Field-weakening regime operation of an interior permanent magnet motor drive[J]. IEEE Transaction on Industry Application, 1987, 23(4): 681-689. [3] Ostovic V. Memory motors[J]. IEEE Industry Applications Magazine, 2003, 99(1): 52-61. [4] Lee J H, Hong J P. Permanent magnet demagnetization characteristics analysis of a variable flux memory motor using coupled preisach modeling and FEM[J]. IEEE Transactions on Magnetics, 2008, 44(6): 1550-1553. [5] 孙建忠, 白凤仙. 新概念永磁电机—记忆电机的设计研究[J]. 大电机技术, 2004(3): 9-12. [6] 陈益广, 王颖, 沈勇环, 等. 宽调速可控磁通永磁同步电机磁路设计和有限元分析[J]. 中国电机工程学报, 2005, 25(20): 157-161. [7] 陈益广, 仲维刚, 沈勇环. 内置混合式可控磁通永磁同步电机有限元分析[J]. 中国电机工程学报, 2009, 29(6): 61-66. [8] 刘恒川, 林鹤云, 郭健, 等. 永磁体形状对可变磁通记忆电机调磁参数影响分析[J]. 电工技术学报, 2009, 24(2): 14-19. [9] Liu Hengchuan, Lin Heyun, Fang Shuhua, et al. Permanent magnet demagnetization physics of a variable flux memory motor[J].IEEE Transactions on Magnetics, 2009, 45(10): 4736-4739. [10] 唐任远, 等. 现代永磁电机理论与设计[M]. 北京: 机械工业出版社, 2001. [11] Talukdar S N, Bailey J R. Hysteresis models for system studies[J]. IEEE Transactions on Power Apparatus and Systems, 1976, PAS-95(4): 1429-1434.
2010, Vol. 25 
