基于二阶滑模算法的永磁同步电机直接转矩控制研究

Direct Torque Control of Permanent Magnet Synchronous Motor Based on the Second Order Sliding Film Algorithm

针对传统永磁同步电机直接转矩控制中存在转矩以及磁链脉动较大,开关频率不恒定以及电机在处于低速时,电压磁链估算存在误差比较大等缺点,提出了一种基于二阶滑模的方法来对永磁同步电机的直接转矩控制进行优化。该方法利用SVPWM空间电压矢量脉宽调制技术取代滞环控制以及传统的开关表,同时在转矩以及磁链的调节中引入二阶滑模控制器代替传统直接转矩控制中的PI调节器来减少磁链以及转矩误差造成的影响,加强转矩和磁链在控制上的精度,抑制转矩以及磁链的脉动。仿真结果显示与传统的直接转矩相比较,新的控制方法可以有效的降低磁链和转矩脉动,提高系统的鲁棒性,改善系统动态性能。

Aiming at the disadvantages of traditional direct torque control for permanent magnet synchronous motor , such as large torque ripple and flux linkage, unsteady switching frequency and large error in voltage flux estimation when the motor is in low speed, etc.A second order sliding mode method is proposed to optimize the direct torque control of PMSM.The method replaces hysteresis control and traditional switch table with SVPWM space voltage vector pulse width modulation technology, and introduces second-order sliding mode controller in torque and flux linkage adjustment instead of PI regulator in traditional direct torque control. Reduce the influence of the flux linkage and the estimation error of the rotational speed, suppress the torque ripple and flux pulsation.The simulation results show that compared with the traditional direct torque, the new control method can effectively reduce the flux linkage and torque ripple, so that the control system has stronger robustness and better dynamic performance.