基于改进分数阶滑模的PMSM无传感器控制

Sensorless Control of PMSM Based on Improved Fractional-Order Sliding Mode

针对永磁同步电机在运行过程中易受扰动影响以及传统滑模观测器使用符号函数会给系统带来高频抖振使转子位置观测精度不高等问题,为了提高系统的抗干扰能力以及转子位置的观测精度,提出了一种基于分数阶滑模线性自抗扰转速、电流复合控制器及改进超螺旋算法滑模观测器的无传感器控制方法。首先,采用改进型三阶线性扩展状态观测器观测系统扰动并反馈给控制器;其次,将传统线性自抗扰控制中的线性误差反馈控制律用新型分数阶滑模趋近律代替,构建分数阶滑模线性自抗扰转速、电流复合控制器;最后,对传统超螺旋算法中的符号函数进行分数阶微分、用变换函数代替非线性项指数的常数,设计基于分数阶的改进超螺旋算法滑模观测器。仿真结果表明,该方法具有无超调、抗干扰能力强、调节速度快以及转子位置观测精度高等特点。

Aiming at the problem that permanent magnet synchronous motor is susceptible to disturbance during operation and that the use of symbol function by traditional sliding mode observer will bring high-frequency buffeting to the system and make the observation accuracy of rotor position low,in order to improve the anti-interference ability of the system and the observation accuracy of rotor position,a sensorless control method based on fractional order sliding mode linear active-disturbance rejection speed and current composite controller and improved super-twistingalgorithm sliding mode observer is proposed.Firstly,the improved third-order linear extended state Observer is used to observe the system disturbance and feed it back to the controller.Secondly,the linear error feedback control law in traditional linear active disturbance rejection control is replaced by a new fractional-order sliding mode approach law,and a fractional-order sliding mode linear active disturbance rejection speed and current compound controller is constructed.Finally,the symbol function of the traditional super-twisting algorithm is differentiated by fractional order,and the constant of the exponential of the nonlinear term is replaced by the transformation function.The simulation results show that this method has the characteristics of no overshoot,strong anti-interference ability,fast adjustment speed and high precision of rotor position observation.