Nonlinear decoupling control for bearingless induction motor based on support vector machines inversion

The bearingless induction motor is a nonlinear, multi-variable and strongly coupled system. To achieve rotor suspension and rotation steadily, it is necessary to realize dynamic decoupling control between torque and suspension force. In this paper, the control strategy based on least squares support vector machines (LS-SVM) α-th order inverse system method is applied to realize the decoupling control for bearingless induction motor. By cascading the inverse system of the bearingless induction motor identified by LS-SVM with the original one, the nonlinear bearingless induction motor system is decoupled into four independent pseudo-linear subsystems, that is, two radial displacement subsystems, a speed subsystem and a rotor flux subsystem. Then, linear control system techniques are applied to these linear subsystems to synthesize and simulation. The study shows that this kind of control strategy can realize dynamic decoupling control between torque and suspension forces of the bearingless induction motor. ©, 2015, Chinese Machine Press. All right reserved.