基于降阶双环自抗扰的永磁同步直线电机电流谐波抑制

永磁同步直线电机由于反电势和逆变器频繁切换导致电流谐波分量较大,同时参数时变以及负载突变等扰动严重影响伺服系统的控制精度。本文采用一种基于降阶状态观测器的双环自抗扰伺服控制算法,以降低控制系统的谐波抑制从而提高控制精度。首先,构造了位置速度环级联的二阶自抗扰控制器。运用极点配置法对三阶线性状态观测器进行降阶,减小了相位滞后的影响,提高了伺服系统的控制精度;其次,电流环采用一阶非线性自抗扰控制器,消除了积分饱和的影响,降低了三相电流的谐波含量。最后,与基于自抗扰控制的其他优化算法进行对比,实验表明在多工况下降阶双环自抗扰控制的总谐波失真不超过2.13%,推力波动可减小至1.49%,稳态误差不大于15μm。

Current harmonic suppression of permanent magnet synchronous linear motor based on reduced-order double closed-loop ADRC

The current harmonic components of permanent magnet synchronous linear motors are high due to back electromotive force and frequent switching of inverters.Moreover,disturbances such as time-varying parameters and sudden load changes seriously affect the control accuracy of servo systems.Therefore,a double closed-loop active disturbance rejection servo control algorithm,based on a reduced-order state observer,was presented to improve the harmonic suppression and control precision of control systems.First,the second-order active disturbance rejection controller of a position-speed loop was constructed.The pole placement method was used to reduce the order of the third-order linear extended state observer.This operation reduced the influence of phase lag and improves the control precision of the servo system.Second,the current loop first-order nonlinear active disturbance rejection controller was employed to eliminate the influence of integral saturation and reduce the harmonic content of the three-phase current.Finally,compared with other optimization algorithms based on active disturbance rejection control(ADRC),the experiments show that the THD of reduced-order double closed-loop ADRC is less than 2.13%,the thrust fluctuation can be reduced to 1.49%,and the steady-state error is less than 15μm under multiple conditions.