Abstract：A direct torque control using new evaluation table of three-level inverter based on duty cycle modulation is proposed for neutral-point clamped three-level inverter-fed permanent magnet synchronous motor drives in order to suppress the steady torque ripples. Firstly, the approach establishes evaluation tables including three vector evaluation tables which evaluate torque and flux of the motor and a compensatory evaluation table which evaluate back electromotive force. The tables are independent to motor parameters in the process of duty modulation adjustment. Secondly, the approach proposes two control schemes for low speed and high speed of the motor. Small vectors and zero vector are employed in the scheme of low speed. Big/medium vectors and small vectors are employed in the scheme of high speed. In this way, the steady of torque is ensured by using the small vectors. Then the vector and duty selection scheme is established based on the cost functions. The proposed algorithm are verified by experiments of a 6kW permanent magnet synchronous motor (PMSM). And the experiment results show that the steady torque ripples are suppressed effectively.
陈炜, 赵迎迎, 周湛清. 采用新型评价表的三电平逆变器占空比调制直接转矩控制[J]. 电工技术学报, 2016, 31(增刊): 128-136.
Chen Wei, Zhao Yingying, Zhou Zhanqing. Direct Torque Control Using New Evaluation Table of Three-Level Inverter Based on Duty Cycle Modulation. Transactions of China Electrotechnical Society, 2016, 31(增刊): 128-136.
[1] Casadei D, Serra G, Tani A, et al. Direct torque control for induction machines: a technology status review[C]//IEEE Workshop on Electrical Machines Design, Control and Diagnosis, Paris, France, 2013: 117-129. [2] 李永东, 侯轩, 谭卓辉. 三电平逆变器异步电动机直接转矩控制系统(I)——单一矢量法[J]. 电工技术学报, 2004, 19(4): 34-39. Li Yongdong, Hou Xuan, Tan Zhuohui. Direct torque control of induction motor fed by three level inverter (I)——single vector method[J]. Transactions of China Electrotechnical Society, 2004, 19(4): 34-39. [3] Lee K B, Song J H, Choy I, et al. Improvement of low-speed operation performance of DTC for three- level inverter-fed induction motors[J]. IEEE Transac- tions on Industrial Electronics, 2001, 48(5): 1006- 1014. [4] Mukherjee S, Poddar G. Direct torque control of squirrel cage induction motor for optimum current ripple using three-level inverter[J]. IET Power Elec- tronics, 2010, 3(6): 904-914. [5] Mohan D, Zhang X, Foo G. Three level inverter fed direct torque control of IPMSM with constant switching frequency and torque ripple reduction[J]. IEEE Transactions on Industrial Electronics, 2016, 63(2): 7908-7918. [6] Zhang Y, Zhu J, Zhao Z, et al. An improved direct torque control for three-level inverter-fed induction motor sensorless drive[J]. IEEE Transactions on Power Electronics, 2012, 27(3): 1502-1513. [7] 刘述喜, 王明渝. 基于快速空间矢量调制算法的三电平直接转矩预测控制系统[J]. 电工技术学报, 2009, 24(2): 35-41. Liu Shuxi, Wang Mingyu. Direct torque predictive control system supplied by three-level inverter based on a fast SVPWM algorithm[J]. Transactions of China Electrotechnical Society, 2009, 24(2): 35-41. [8] 李永东, 侯轩, 谭卓辉. 三电平逆变器异步电动机直接转矩控制系统(II)——合成矢量法[J]. 电工技术学报, 2004, 19(5): 31-35. Li Yongdong, Hou Xuan, Tan Zhuohui. Direct torque control of induction motor fed by three level inverter(II)——method of synthesizing vectors[J]. Transactions of China Electrotechnical Society, 2004, 19(5): 31-35. [9] 林磊, 邹云屏, 钟和清, 等. 基于固定合成矢量的三电平异步电机直接转矩控制[J]. 中国电机工程学报, 2008, 28(27): 120-125. Lin Lei, Zou Yunping, Zhong Heqing, et al. DTC algorithm of induction motors fed by three-level inverter based on fixed synthesizing vector[J]. Procee- dings of the CSEE, 2008, 28(27): 120-125. [10] Lee K B, Song J H, Choy I, et al. Torque ripple reduction in DTC of induction motor driven by three- level inverter with low switching frequency[J]. IEEE Transactions on Power Electronics, 2002, 17(2): 255- 264. [11] Brando G, Dannier A, Del Pizzo A, et al. Generalised look-up table concept for direct torque control in induction drives with multilevel inverters[J]. IET Electric Power Applications, 2015, 9(8): 556-567.
2016, Vol. 31 
