Abstract：A novel method of rotor position identification of brushless DC motor (BLDCM) is proposed by line voltage calculation based on the traditional zero-crossing of back EMF. The unexcited phase back EMF signal is indirectly obtained from line voltage calculation instead of traditional hardware sensing method. The real commutation point is the zero-crossing of back EMF shifted by 30°. The relationship between motor neutral voltage and half DC voltage is detailedly analyzed. In the double switch PWM scheme, the diode freewheeling currents in the unexcited phase are eliminated completely so that double switch PWM strategy is available for proposed rotor position estimation scheme. This method is simple to implement without the need to sense or reconstruct the motor neutral. Neither hardware circuit of sensing back EMF nor depth filter circuit is needed. Simulation and experimental results verify the validity of the proposed scheme of sufficient identification accuracy in a wide speed range.
李自成, 程善美, 蔡凯, 秦忆. 反电动势过零检测无刷直流电机转子位置新方法[J]. 电工技术学报, 2009, 24(7): 52-58.
Li Zicheng, Cheng Shanmei, Cai Kai, Qin Yi. A Novel Scheme of Sensing Rotor Position of BLDCM Based on the Zero-Crossing of Back EMF. Transactions of China Electrotechnical Society, 2009, 24(7): 52-58.
[1] 韦鲲, 任军军, 张仲超. 三次谐波检测无刷直流电机转子位置的研究[J]. 中国电机工程学报, 2004, 24(5): 163-167. [2] Halvaei N A, Hassan M, Abolfazl V. A novel sensorless control method for four-switch, brushless DC motor drive without using any 30°phase shifter[C]. 2007 International Conference on Electrical Machines and Systems, 2007: 408-413. [3] Jang G H, Kim M G. Optimal commutation of a BLDC motor by utilizing the symmetric terminal voltage[J]. IEEE Transactions on Magnetics, 2006, 42(10): 3473-3475. [4] Hicham F, Mohamed D, Abdellatif R, et al. Sliding mode observer for position and speed estimations in brushless DC motor[C]. 2004 IEEE International Conference on Industrial Technology, 2004, 1: 121- 126. [5] Su G J, Mckeever J W. Low-cost sensorless control of brushless dc motors with improved speed range[J]. IEEE Transactions on Power Electronics, 2004, 19(2): 296-302. [6] Shao Jianwen, Nolan D, Hopkins T. A novel microcontroller-based sensorless brushless DC (BLDC) motor drive for automotive fuel pumps[J]. IEEE Trans- actions on Industry Applications, 2003, 39(6): 1734- 1740. [7] 张磊, 瞿文龙, 陆海峰, 等. 一种新颖的无刷直流电机无位置传感器控制系统[J]. 电工技术学报, 2006, 21(10): 26-30. [8] Chen Kuangyao, Tzou Yingyu. Design of a sensorless commutation IC for BLDC motors[J]. IEEE Transactions on Power Electronics, 2003, 18(6): 1365- 1375. [9] Lai Yenshin, Lin Youngkai. A unified approach to back-EMF detection for brushless DC motor derives without current and hall sensors[J]. IEEE Transactions on Power Electronics, 2003, 18(6): 1293-1298. [10] 王宏伟, 梁晖. 无位置传感器无刷直流电机的DSP控制[J]. 电力电子技术, 2005, 39(6): 102-104. [11] Wu Zhigan, Zhou Genfu, Ying Jianping. High dynamic sensorless BLDCM drive with very wide speed range[C]. 2004 IEEE Annual Conference of Industrial Electronics Society, 2004, 1: 981-986. [12] 张相军, 陈伯时, 朱平平, 等. 直流无刷电机无位置传感器控制中反电动势过零检测算法及其相位修正[J]. 电气传动, 2001(2): 14-16. [13] Li Qiang, Wang Ruixia. Study on rotor position detection error in sensorless BLDC motor drives[C]. 2006 International Conference on Power Electronics and Motion Control, 2006, 3: 1-5. [14] 杜晓芸, 林瑞光, 吴建华. 无位置传感器无刷直流电机的控制策略[J]. 电机与控制学报, 2002, 6(1): 21-25. [15] 吴春华, 陈国呈, 孙承波. 一种改进的无刷直流电机无位置传感器检测技术[J]. 电气传动自动化, 2005, 27(3): 31-33. [16] Damodharan P, Vasudevan K. Indirect back-EMF zero crossing detection for sensorless BLDC motor operation[C]. 2005 IEEE Annual Meeting of PEDS, 2005, 1: 1107-1111. [17] Kim T H, Ehsani M. Sensorless control of the BLDC motors from near-zero to high speeds[J]. IEEE Transactions on Power Electronics, 2004, 19(6): 1635-1645. [18] Zhu Z Q, Liu Y, Howe D. Comparison of performance of brushless DC drives under direct torque control and PWM current control[C]. 2005 International Conference on Electrical Machines and Systems, 2005, 2: 1486- 1491.
2009, Vol. 24 
