基于滑模控制的三电平直接转矩控制算法

磁链和转矩的估计是直接转矩控制技术的关键。本文提出了一种基于滑模控制的电压型磁链观测器,在M-T旋转坐标系下利用定子电流的实际值和观测值的误差构成滑模面,通过选择合适的在线调节参数,实现了磁链的闭环控制,弥补了传统磁链观测器中积分漂移、积分饱和以及低速区定子电阻影响等缺陷,减小了输出转矩脉动,提高了系统的鲁棒性;同时采用一种简化的三电平SVPWM算法,使得输出更加接近目标电压,降低了输出谐波分量,提高了系统的电压和功率等级。最终采用Matlab/Simulink进行仿真,通过传统直接转矩控制方案改进方案进行对比,验证了该改进方案的合理性。

Three-level Direct Torque Control Algorithm Based on Sliding Mode Control

The estimation of flux and torque is the key to direct torque control technology.In this paper,a voltage model flux observer based on sliding mode control is proposed.In the M-T rotating coordinate system,the sliding mode surface is formed by the difference between the actual value of the stator current and the observed value.By selecting the appropriate online adjustment parameters,the closed-loop control of the flux linkage is realized,overcoming the defects of integral drift,integral saturation and stator resistance effects in the low-speed region of the traditional flux observer,Reduced output torque ripple and improve the system's robustness.At the same time,a simplified three-level SVPWM algorithm is added to make the output voltage closer to the target one,which reduce the output harmonic components and improve the system voltage and power level.The simulations were carried out using Matlab/Simulink simulation package.The simulation results from the comparisons between the traditional direct torque control and the proposed algorithm verifies the rationality of the improved algorithm.