Abstract：In the field of industrial and rail transportation, multi-motor coordination and control has been widely used The purpose of this paper is to solve the problem of paralleled induction motors driven by a single inverter under unbalanced load. This paper presents a speed-sensorless weighted vector control method. The existing method of weight control is improved. When the load is unbalanced, the weighting value is calculated in real time according to the motor speeds which are easily available. The vector control of paralleled motors can be readjusted according to the weighted value. The q-axis component of stator current is used to control the weighted torque of two motors, and the d-axis component of stator current is used to control the weighted rotor flux. The parameters of each motor, namely rotor flux, and speed were estimated using q-axis flux observers. The simulation and experiment results proved that the presented method overcomes the shortcoming of mean rotor flux oriented method which may not start at heavy unbalanced load and reduce the degree of stator current imbalance.
[1] 李卫超, 胡安, 聂子玲. 感应电机并联运行量控制系统仿真研究[J]. 电机与控制学报, 2006, 10(1): 102-106. Li Weichao, Hu An, Nie Ziling. Field-oriented control of parallel-connected induction motors[J]. Transactions of China Electrotechnical Society, 2006, 21(11): 21-27. [2] Matsumoto Y, Ozaki S, Kawamura A. A novel vector control of single inverter multiple-induction-motors drives for Shinkansen traction system[C]. Sixteenth Annual IEEE Applied Power Electronics Conference and Exposition, 2001, 1: 608-614. [3] Matsumoto Y, Osawa C, Mizukami T, et al. A stator- flux-based vector control method for parallel-connected multiple induction motors fed by a single inverter[C]. IEEE Thirteenth Annual Applied Power Electronics Conference and Exposition, 1998, 2: 575-580. [4] Kadowaki S, Ohishi K, Miyashita I, et al. Re-adhesion control of electric motor coach based on disturbance observer and sensorless vector control[C]. Proceedings of the IEEE Power Conversion Conference, 2002, 3: 1020-1025. [5] Kelecy P M, Lorenz R D. Control methodology for single inverter, parallel connected dual induction motor drives for electric vehicles[C]. 25th Annual IEEE Power Electronics Specialists Conference, 1994: 987-991. [6] 张倩倩, 周西峰, 郭前岗. 基于双模态控制的异步电机并联运行方法的研究[J]. 电气自动化, 2011, 33(2): 1-3. Zhang Qianqian, Zhou Xifeng, Guo Qiangang. Study of control methodology for parallel running induction motors based on two state control method[J]. Electric Automation, 2011, 33(2): 1-3. [7] Matsuse K, Kouno Y, Kawai H, et al. A speed- sensorless vector control method of parallel-connected dual induction motor fed by a single inverter[J]. IEEE Transactions on Industry Applications, 2002, 38(6): 1566-1571. [8] Matsuse K, Kawai H, Kouno Y, et al. Characteristics of speed sensorless vector controlled dual induction motor drive connected in parallel fed by a single inverter[J]. IEEE Transactions on Industry Applications, 2004, 40(1): 153-161. [9] 汪斌, 卢琴芬, 黄晓艳. 列车牵引电机负荷不平衡问题及控制策略研究[J]. 电气传动, 2012, 42(10): 22-26. Wang Bin, Lu Qinfen, Huang Xiaoyan. Study of load imbalance problem and control stategy of train traction motor[J]. Electric Drive, 2012, 42(10): 22-26. [10] Alain B, Maria P D, Phillipe D, et al．Weighted control of traction drives with parallel-connected AC machines[J]. IEEE Transactions on Industrial Elec- tronics, 2006, 53(6): 1799-1806． [11] 徐飞, 史黎明, 李耀华. 单变频器驱动非耦合两异步电机加权矢量控制[J]. 中国电机工程学报, 2013, 33(12): 131-137. [12] 葛兴来, 陆阳, 冯晓云. DJ1交流传动电力机车并联电机功率偏差的研究[J]. 铁道机车车辆, 2004, 24(1): 28-30. Ge Xinglai, Lu Yang, Feng Xiaoyun. Study of parallelled motor power deviation of DJ1 AC drive electric locomotive[J]. Railway Locomotive, 2004, 24(1): 28-30.
2015, Vol. 30 
