模糊控制在感应电动机直接转矩控制中的应用

Application of Fuzzy Control in Direct Torque Control of an Induction Motor

电机控制的关键是控制电机的转矩.继矢量控制后提出的直接转矩控制,直接着眼于对感应电动机瞬时力矩的控制,避免了矢量控制存在的一些问题.在通常的直接转矩控制系统中,磁链误差和转矩误差被直接用于开关状态选择,而引入模糊逻辑后,通过区分磁链误差和转矩误差的大小做不同的决策来优化开关状态选择,从而有效地改善系统的动态和稳态性能.给出了模糊控制器的设计,并通过仿真验证了该设计的有效性,电机启动时定子电流脉动减少,转矩脉动得到改善.

The key of motor control is to control motor＇s torque essentially. Direct torque control, which emerged after the field-oriented control, directly stresses the instantaneous torque control of induction machine, which avoids some problems existing in field-oriented control, thus, it gets more attention. In conventional direct torque control system, switch vector is selected directly by the errors of stator flux-linkage and torque, after introducing fuzzy logic, optimal selecting switch state is realized by various strategies by distinguishing the grade of the errors of stator flux-linkage and torque, the dynamic and steady state performances of induction motors are improved. This paper presents a design method of the fuzzy controller. Simulation results demonstrate that it is effective, the stator currents pulsation at start-up and the torque pulsation are decreased.