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BLDC motor commutation position optimization strategy based on bus current
ZHANG Qian , FENG Ming
School of Mechanical Engineering, University of Science and Technology Beijing, Beijing 100083, China
Received: 2015-06-26; Accepted: 2015-08-26; Published online: 2015-11-16 50:00
Foundation item: National High-tech Research and Development Program of China (SS2012AA110501)
Corresponding author. Tel.: 010-82376928 E-mail: mingfeng@me.ustb.edu.cn
Abstract: This paper analyzes the relation between commutation position of brushless direct current (BLDC) motors and bus current, builds up their mathematical relation, and proposes a sensorless BLDC motors commutation position optimization strategy. This strategy regulates the commutation position by a proportional integral (PI) adjuster, aiming at regulating the current and the back electromotive force (BEMF) in-phase. The controlled variable of the PI adjuster is the commutation position compensating angle and the deviation value is the ratio of current change over angle. This optimization strategy can revise the detected position signal error and the phase deviation caused by the winding inductance at the same time. The experimental results verify that this optimization strategy can get the best commutation position accurately and fast, and improve the operating efficiency effectively.
Key words: brushless direct current (BLDC) motor     sensorless     bus current     commutation position optimization     back electromotive force (BEMF) method

1 换相位置对母线电流的影响

1.1 电枢电流与反电动势同相时的功率

 图 1 无相位差时a相电枢电流与反电动势波形 Fig. 1 Armature current and BEMF waveform of phase a with no commutation error

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1.2 电枢电流与反电动势不同相时的功率

 图 2 不同相时三相电枢电流与反电动势波形 Fig. 2 Armature current and BEMF waveform of triphase with commutation error
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1.3 换相角度偏差对母线电流的影响

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θ > 0时，该换相周期内各相反电动势的值为

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 图 3 母线电流与换相角度偏差的关系 Fig. 3 Relationship between bus current and angular commutation deviation
2 换相位置优化策略在驱动系统中的实现 2.1 构建PI调节器

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 图 4 母线电流变化率与换相角度偏差的关系 Fig. 4 Relationship between bus current gradient and angular commutation deviation

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2.2 调速系统逻辑框图

 图 5 采用换相位置优化策略的调速系统逻辑框图 Fig. 5 Logic diagram of speed control system using commutation position optimization strategy

3 实验验证 3.1 实验装置

 图 6 实验装置 Fig. 6 Experimental devices

 图 7 实验用驱动器原理框图 Fig. 7 Principle diagram of experimental drive

 电机参数 数值 额定功率/kW 10 额定转速/(r·min-1) 100 000 待机转速/(r·min-1) 15 000 极对数 1 线电感/μH 80 线电阻/mΩ 40 额定电流/A 50 额定电压/V 250

3.2 稳态实验分析

 图 8 a相电流及端电压波形 Fig. 8 Current and terminal voltage waveforms of phase a

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 图 9 换相位置优化前后母线电流 Fig. 9 Bus current before and after commutation position optimization

 转速/(r·min-1) 最佳换相延时/(°) 换相延时区间/(°) 15 000 τ+8 (τ+4)~(τ+12) 20 000 τ+4 (τ+2)~(τ+8) 25 000 τ+6 (τ+4)~(τ+10) 30 000 τ+6 (τ+4)~(τ+8)

3.3 动态实验分析

 加速过程转速/(r·min-1) 加速时间/s 加速过程电流/A 优化前 优化后 优化前 优化后 15 000~20 000 3.6 3.4 6.37 6.29 20 000~25 000 3.2 3.0 9.27 9.19 25 000~30 000 3.4 3.0 12.87 12.69

 图 10 换相位置优化前后实验波形 Fig. 10 Experimental waveform before and after commutation position optimization
4 结论

1)该策略可以准确调节换相位置到最优换相点，有效减小母线电流，改善相电流及端电压波形，提高无刷直流电机运行效率。

2)可以同时校正位置信号检测误差和绕组电感引起的电流相位滞后，避免了采用换相位置优化策略时无法进行相位超前角控制的问题。

3)无需计算偏差的具体值，而是通过PI调节使换相位置在最优换相点附近小幅波动，因此无需复杂的计算，简化了优化过程。

4)通过采样母线电流作为调节依据，无需检测每次换相时的电流或电压，对运算速度及采样频率要求较低，可以节约CPU资源，适用于高速驱动场合。

 [1] ACARNLEY P P, WATSON J F. Review of position-sensorless operation of brushless permanent-magnet machines[J]. IEEE Transactions on Industrial Electronics, 2006, 53 (2) : 352 –362. DOI:10.1109/TIE.2006.870868 [2] DAMODHARAN P, VASUDEVAN K. Sensorless brushless DC motor drive based on the zero-crossing detection of back electromotive force(EMF) from the line voltage difference[J]. IEEE Transactions on Energy Conversion, 2010, 25 (3) : 661 –668. DOI:10.1109/TEC.2010.2041781 [3] BI C, HLA N P, JIANG Q, et al. Back-EMF ZCP error induced by electromagnetic structure of spindle motor[J]. IEEE Transactions on Magnetics, 2011, 47 (7) : 1899 –1905. DOI:10.1109/TMAG.2011.2157895 [4] ZWYSSIG C, KOLAR J W, ROUND S D. Megaspeed drive systems:Pushing beyond 1 million r/min[J]. IEEE/ASME Transactions on Mechatronics, 2009, 14 (5) : 564 –574. DOI:10.1109/TMECH.2008.2009310 [5] OGASAWARA S, AKAGI H. An approach to position sensorless drive for brushless DC motors[J]. IEEE Transactions on Industry Applications, 1991, 27 (5) : 928 –933. DOI:10.1109/28.90349 [6] ERTUGRUL N, ACARNLEY P. A new algorithm for sensorless operation of permanent magnet motors[J]. IEEE Transactions on Industry Applications, 1994, 30 (1) : 126 –133. DOI:10.1109/28.273630 [7] FAKHAM H, DJEMAI M, BUSAWON K. Design and practical implementation of a back-EMF sliding-mode observer for a brushless DC motor[J]. IET Electric Power Applications, 2008, 2 (6) : 353 –361. DOI:10.1049/iet-epa:20070242 [8] KASA N, WATANABE H. A mechanical sensorless control system for salient-pole brushless DC motor with autocalibration of estimated position angles[J]. IEEE Transactions on Power Electronics, 2000, 47 (2) : 389 –395. [9] 宋飞, 周波, 吴小婧. 校正无位置传感器无刷直流电机位置信号相位的闭环控制策略[J]. 中国电机工程学报, 2009, 29 (12) : 52 –57. SONG F, ZHOU B, WU X J. Closed loop control method to correct position phase for sensorless brushless DC motor[J]. Proceedings of the CSEE, 2009, 29 (12) : 52 –57. (in Chinese) [10] 吴小婧, 周波, 宋飞. 基于端电压对称的无位置传感器无刷直流电机位置信号相位校正[J]. 电工技术学报, 2009, 24 (4) : 54 –60. WU X J, ZHOU B, SONG F. A new control method to correct position phase for sensorless brushless DC motor[J]. Transactions of China Electrotechnical Society, 2009, 24 (4) : 54 –60. (in Chinese) [11] 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. WEI K, REN J J, ZHANG Z C. Research on the scheme of sensing rotor position of BLDCM based on the third harmonic component[J]. Proceedings of the CSEE, 2004, 24 (5) : 163 –167. (in Chinese) [12] LIN M Y, LI Q, GU W G.Effect of rotor position error on commutation in sensorless BLDC motor drives[C]//8th International Conference on Electrical Machines and Systems(ICEMS 2005).Piscataway, NJ:IEEE Press, 2005. [13] SAMOYLENKO N, HAN Q, JATSKEVICH J.Balancing hall-effect signals in low-precision brushless DC motors[C]//Applied Power Electronics Conference(APEC 2007).Piscataway, NJ:IEEE Press, 2007. [14] JIANG Q, BI C, HUANG R Y. A new phase-delay-free method to detect back EMF zero-crossing points for sensorless control of spindle motros[J]. IEEE Transactions on Magnetics, 2005, 41 (7) : 2287 –2294. DOI:10.1109/TMAG.2005.851841 [15] SHEN J X, TSENG K J. Analysis and compensation of rotor position detection error in sensorless PM brushelss DC motor drives[J]. IEEE Transactions on Energy Conversion, 2003, 18 (1) : 87 –93. DOI:10.1109/TEC.2002.808339 [16] HAN Q, SAMOYLENKO N, JATSKEVICH J. Average-value modeling of brushless DC motors with 120° voltage source inverter[J]. IEEE Transactions on Energy Conversion, 2008, 23 (2) : 423 –432. DOI:10.1109/TEC.2008.918628

#### 文章信息

ZHANG Qian, FENG Ming

BLDC motor commutation position optimization strategy based on bus current

Journal of Beijing University of Aeronautics and Astronsutics, 2016, 42(7): 1441-1448
http://dx.doi.org/10.13700/j.bh.1001-5965.2015.0429