基于预前控制异步电机直接转矩控制方案的研究

Study of Direct Torque Control of Induction Motor Based on Predictive Control Scheme

在传统异步电动机直接转矩控制方案中,由于负载的变化规律不可预测,因此其常会带来功率器件开关频率的较大变化,为此提出了一种基于预前控制的异步电动机直接转矩控制方法。该方法依据前一个周期的磁链和转矩误差,对下一个开关周期所应施加到异步电动机的定子电压矢量进行预测,然后借助空间矢量PWM的方法,合成此开关电压矢量。样机实验结果表明,该方案不但能维持逆变器的开关频率基本恒定,而且还具有比传统直接转矩控制更为优良的动静态特性。

In the traditional direct torque control scheme of asynchronous motor, the change of the load is unpredictable, so there is often a big change of the switching frequency. This paper proposed a direct torque control scheme based on predictive control method, according to torque and flux error of last period, the predictive control scheme estimated the value of voltage space vector which should be added to the stator next period. Then using of the space vector PWM technique, we synthesize this voltage space vector. All the experimental results validate the work, it not only has a constant switching frequency, but also has a good performance.