无轴承异步电机具有非线性、多变量和强耦合的特点,要实现电机稳定悬浮和旋转运行。必须对其进行非线性动态解耦控制。为了克服逆系统方法精确建模难的局限性,采用基于最小二乘支持向量机(LS-SVM)α阶逆系统方法对无轴承异步电机进行动态解耦控制的研究。首先利用最小二乘支持向量机辨识出无轴承异步电机的逆模型,然后将它串联在原系统前,将无轴承异步电机解耦成四个独立的伪线性子系统-2个径向位移子系统、一个速度子系统和一个磁链子系统。为保证鲁棒性能,最后对解耦后的系统采用非线性内模控制策略。研究表明,LS-SVMα阶逆系统方法能够实现无轴承异步电机径向悬浮力和旋转力之间的动态解耦控制,控制系统具有良好的静态和动态性能。
The bearingless induction motor has the characteristic of nonlinear, multivariable and strongly coupling. To achieve rotor suspension and rotation steadily, it is necessary to realize dynamic decoupling control. To overcome the disadvantage of the analytic inverse system method, by which the accurate mathematical model description is difficult to require. The least squares support vector machines (LS-SVM) α-th order inverse system method is applied to realize the dynamic decoupling control for bearingless induction motor in this paper. By cascading the inverse system of the bearingless induction motor identified by LS-SVM with the original one, the bearingless induction motor is decoupled into four independent pseudo-linear subsystems, that is, two radial displacement subsystems, a speed subsystem and a rotor flux subsystem. To ensure the robustness of the whole control system, nonlinear internal model control stategy is applied finally. The study shows that the proposed control strategy can realize dynamic decoupling control between torque and radial suspension forces of the bearingless induction motor, and that the control system has good dynamic and static performance.