直接转矩控制在异步电动机低速段的改善和仿真

Improvement and Simulation of Direct Torque Control for Low-Speed Section of Asynchronous Motor

介绍了交流传动控制系统的特点,较为系统、深入地研究了异步电机的新型控制(即DTC——直接转矩控制)策略,论述DTC方法在交流传动方面控制方法,针对异步电机在低速段直接转矩控制的缺陷进行改善.提出了以下解决方案:使用改进的开关表;使用三点式带滞环的比较器;解决了异步电动机直接转矩控制低速段时,难于控制转矩、磁通和电流、转矩脉动大的问题.通过Matlab6.5/simulink的建立仿真模型进行仿真验证,仿真结果表明对低速性能的改善是有效的.

The features of control system in AC drive is introduced, and a new direct torque control strategy is systematically and thoroughly studied. The improvement of DTC is discussed in low-speed running section with the use of improved switching tables and comparators with hysteresis at three levels. Thus, a solution is found to control torque and flux at very low speed, and high current and ＂torque ripple problems. A model system based on Matlab 6.5/simulink is developed according to the DTC theory. Simulating results show that the models developed have excellent performance.