A Simplfied Voltage Vector Selection Strategy for Direct Torque Control
Li Yaohua Li Yaohua, Liu Jingyu, Ma Jian Ma Jian, Yu Qiang Yu Qiang
Abstract
The direct torque control (DTC) for permanent magnet synchronous motor (PMSM) under the control of switching table suffers from high torque ripple and variable switching frequency. For PMSM DTC system, voltage vector selection strategy as the hysteresis control principle determines the system’s performance. The angle (a) between stator flux vector and the applying voltage vector determines effect of the voltage vector on the amplitude of stator flux and torque angle. The effect of the voltage vector on toque is dependent on a, torque angle and parameters of PMSM. A voltage vector selection strategy based on the technology of space vector modulation (SVM) is proposed to control stator flux, torque angle and torque. Experimental results for a 15-kW interior PMSM show it can decrease stator current and torque ripples and fix the switching frequency.
Zhong L, Rahman MF, Hu WY, Lim KW. Analysis of direct torque control in permanent magnet synchronous motor drives. IEEE Transactions on Power Electronics. 1997; 12(3): 528-536.
Zhong L, Rahman MF, Hu WY, Lim KW. A direct torque controller for permanent magnet synchronous motor drives. IEEE Transactions on Energy Conversion. 1999; 14(3): 637-642.
Rahman MF, Zhong L, Lim LW. A direct torque-controlled interior permanent magnet synchronous motor drives incorporating field weakening. IEEE Transactions on Industry Application. 1998; 34(6): 1246-1253.
Yaohua Li, Weiguo Liu. Simulation Study on the Effect of Voltage Vector on Torque in Direct Torque Control System of Permanent Magnet Synchronous Motor. The Second IEEE Conference on Industrial Electronics and Applications (ICIEA). Harbin. 2007: 1521-1525.
Yaohua Li, Dieter Gerling, Weiguo Liu. A Novel Switching Table to Suppress Unreasonable Torque Ripple for the PMSM DTC Drives. International Conference on Electrical Machines and Systems (ICEMS). 2008: 972-977.
Yaohua Li, Dieter Gerling, Weiguo Liu. The Control of Stator Flux and Torque in the Surface Permanent Magnet Synchronous Motor Direct Torque Control System. The 4th IEEE Conference on Industrial Electronics and Applications (ICIEA). Xi’an. 2009: 2004-2009.
Li YH, Gerling D, Liu WG. A Simplified Voltage Vector Selection Strategy for the Permanent Magnet Synchronous Motor Direct Torque Control Drive with Low Torque Ripple and Fixed Switching Frequency. The 13rd International Conference on Electrical Machines and Systems. Brasov. 2010: 674-679.
Li YH, Gerling D, Liu WG. The Comparison of Control Strategies for the interior PMSM drive used in the Electric Vehicle. The 25th World Battery, Hybrid and Fuel Cell Electric Vehicle Symposium & Exhibition. Shenzhen. 2010; Report number: 4C-7.
