感应电动机低速运行时带磁通补偿的直接转矩控制

Flux Compensated Direct Torque Control of Induction Motor Drives for Low Speed Operation

直接转矩控制的感应电动机的速度控制需要有效地建立定子磁通。但当电动机运行在低速区时就很困难,因为定子电阻上的压降与输入定子电压近似,不可忽略。由此,提出了一种简单而有效的方法来补偿定子电阻上的压降,从而构建定子磁通时无需像大多数专家那样需要确定定子电阻。这样就通过有效的定子磁通补偿建立了电动机转矩,使得直接转矩控制在感应电动机的低速区也同样适用。

Speed control of direct torque controlled （DTC） induction motor drives depends on effectively establishing the stator flux. However, it becomes difficult when the motor operates in the low speed region, because the voltage drop on the stator resistance is comparable with the input stator voltage. Therefore, this study proposes an easy but effective way to compensate the voltage drop on the stator resistance so that the stator flux can be constructed without identifying the stator resistance as done by most authors. As a result, motor torque is constructed due to the effective stator flux compensation, which makes the DTC applicable to induction motor drives in the low speed region. Moreover, a fixed-point digital signal processor （DPS）-based hardware experimental system is built to demonstrate the effectiveness of the proposed control method.