具有恒定开关频率的感应电机无速度传感器直接转矩控制

Speed-Sensorless Direct Torque Control of the Induction Motor with the Persistent Switch Frequency

介绍了一种具有恒定开关频率的新型直接转矩控制方法 ,通过定子磁链、定子电压与同步角速度之间的关系式实时计算下一个控制周期内需要加在电机定子绕组上的电压 ,实现了对感应电机的动态解耦控制 ,采用空间电压矢量调制的方法使逆变器开关器件处于恒定频率工作状态。在低速下较传统直接转矩控制方法具有更优的控制性能 ,在高速下与传统直接转矩控制方法同样具有响应快、性能不受电机参数影响等优点 ,并介绍了该方法的无速度传感器实现 。

A new method of the direct torque control with the persistent switch frequency is presented in this paper. By means of relationship equations of the stator voltage, stator flux and synchronous speed, the stator voltage needed in the next sample period is calculated, and the decoupled control of the induction motor is realized. So the space voltage vector pulse width modulation method is adopted to realize the persistent switch frequency of inverter switch devices. In the low speed region, the proposed method has better performance than the conventional method; and the new method has the same advantages as the conventional method in the high speed region, which is characterized by fast response and performance unaffected by motor parameter changing. The sensorless method is also described and the simulation result illustrates the effectiveness of the proposed method.