Abstract：This paper introduces a novel instantaneous speed detection method for permanent magnet synchronous motors (PMSMs). High detection precision is achieved by using a low resolution encoder. First, instantaneous speed and disturbance torque are estimated by a Luenberger observer based on the motion model of PMSM. Then, the estimation errors are corrected by angular position, which is obtained by synchronous sampling method (SSM) or asynchronous sampling method (ASM) according to different speed. Furthermore, in order to reduce the influence of load variation on instantaneous speed observer, load inertia is identified using the estimated values of speed and disturbance torque, and then the parameters of speed observer are adjusted according to load inertia. Compared with traditional speed observer, the method mentioned above eliminates the position detection error and delay time. So detection precision of instantaneous speed is improved largely especially in low speed region.
[1] Tsuji T, Mizuochi M, Nishi H, et al. A velocity measurement method for acceleration control[C]. 31st Industrial Electronics Society Annual Conference of IEEE, 2005: 1943-1948. [2] 江冰, 毛建军. 锁相环技术在转速检测中的应用[J]. 微计算机信息, 2001, 17(3): 43-44. [3] Yucheng B, Xiaoqi T, Jihong C, et al. Research on ultra-low speed control of PMSM in servo system[C]. 7th World Congress on Intelligent Control and Automation, 2008: 2381-2386. [4] 秦晓飞, 王云宽, 郑军, 等. 交流伺服系统振动鲁棒M/T测速算法[J]. 电机与控制学报, 2010, 14(5): 97-103. [5] 万山明, 吴芳, 黄声华. 永磁同步电机超低速下的转速检测及控制[J]. 微电机, 2007, 40(8): 65-67, 71. [6] Wang Gaolin, Xu Dianguo, Yu Yong, et al. Low speed control of permanent magnet synchronous motor based on instantaneous speed estimation[C]. The Sixth World Congress on Intelligent Control and Automation, 2006, 2: 8033-8036. [7] Lee Se Han, Song Jae Bok. Acceleration estimator for low-velocity and low-acceleration regions based on encoder position data[J]. IEEE/ASME Transactions on Mechatronics, 2001, 6(1): 58-64. [8] Song Seung Ho, Sul Seung Ki. An instantaneous speed observer for low speed control of AC machine[C]. Proceedings of Thirteenth Annual Conference on Applied Power Electronics Conference and Exposition, 1998, 2: 581-586. [9] Lilit K, Takafumi K. Precise speed estimation from a low-resolution encoder by dual-sampling-rate observer[J]. IEEE/ASME Transactions on Mechatronics, 2006, 11(2): 661-670. [10] Wang Gaolin, Xu Dianguo, Yu Yong, et al. Low speed control of PMAC servo system based on reduced-order observer[C]. IEEE International Conference on Intelligent Robots and Systems, 2006: 4886-4889. [11] Lilit Kovudhikulrungsri L, Takafumi Koseki. Precise torque and speed control in pure electric braking operation of AC traction in low speed range[C]. 7th International Workshop on Advanced Motion Control, 2002: 142-147. [12] Liang Shihua, Liu Zhigang. Adaptive speed control for permanent-magnet synchronous motor system with variations of load inertia[J]. IEEE Transactions on Industrial Electronics, 2009, 56(8): 3050-3059. [13] 刘永钦, 沈艳霞, 纪志成. 基于改进型最小二乘法的感应电机转动惯量辨识[J]. 电机与控制应用, 2008, 35(12): 13-17. [14] 王晓伟. 永磁交流伺服系统的惯量辨识[J]. 伺服控制, 2008, 5(7): 49-50. [15] 刘志刚, 李世华. 基于永磁同步电机模型辨识与补偿的自抗扰控制器[J]. 中国电机工程学报, 2008, 28(24): 118-123. [16] Awaya I, Kato Y, Miyake I, et al. New motion control with inertia identification function using disturbance observer[C]. International Conference on Power Electronics and Motion Control, 1992: 77-81.
2011, Vol. 26 
