基于二阶滑模的永磁同步电机直接转矩控制研究

Research on Direct Torque Control of Permanent Magnet Synchronous Motor Based on Second Order Sliding Mode Algorithm

为解决传统直接转矩控制系统中存在的定子磁链与电磁转矩波动较大问题,提出了一种基于滑模变结构的控制方案。利用SVPWM空间电压矢量脉冲宽度调制代替滞环控制以及开关表,用转矩与磁链的二阶滑模控制器取代传统PI调节器,加强了转矩和磁链的控制精度,抑制其抖振。用滑模观测器代替传感器,提高了调速系统的控制性能和抗干扰能力。Matlab仿真实验结果表明:改进后的控制系统可以有效地降低磁链和转矩脉动,改善其静态、动态性能及系统的鲁棒性。

In order to solve the problem of stator flux linkage and electromagnetic torque found in traditional direct torque control system,a control scheme based on sliding mode variable structure has thus been proposed.With SVPWM space voltage vector pulse width modulation adopted to replace hysteresis control and switch table,the second-order sliding mode controller of torque and flux linkage is used to replace traditional PI regulator,thus enhancing the control precision of torque and flux linkage and restraining its buffeting.The utilization of the sliding mode observer instead of the sensor helps to improve the control performance and anti-interference ability of speed control system.Matlab simulation results show that the improved control system can effectively reduce the flux linkage and torque ripple,improve its static and dynamic performance and robustness of the system as well.