分数阶滑模趋近率在SMVS-DTC中的应用

Application of Fractional Order Reaching Law in the Direct Torque Control based on the Sliding Mode Variable Structure

为了减小基于滑模变结构的直接转矩控制技术中存在的转矩、磁链脉动,以及系统抖振等问题,提出一种改进型的分数阶滑模控制器。分析了分数阶指数函数曲线的特性,并在滑模切换面设计中引入了分数阶积分项来减小转矩、磁链脉动,同时采用分数阶微分方程和指数趋近率相结合的新型趋近率来提高收敛速度、减小暂态过程中的超调量。仿真结果显示,改进后的分数阶滑模控制器能明显减小系统抖动,更快地到达稳定状态,并且对干扰信号有较强的鲁棒性。

An improved fractional order sliding mode controller was proposed to further reduce torque and flux ripple as well as system chattering, etc. in the direct torque control based on the sliding mode variable structure （SMVS-DTC）. The characteristic of fractional order exponential function curve was analyzed, and a fractional order integral term in the design of sliding mode switching surface was introduced to reduce torque and flux ripple, while a new reaching law was combined fractional order differential equations with exponential reaching law was adopted to improve convergence rate and reduce o- vershoot during the transient process. Simulation results show that the improved fractional order sliding mode controller can significantly reduce system chattering, reach a steady state faster and have strong robustness to the interfering signal.