Affiliations: [a] Electrical Engineering College, Henan University of Science and Technology, Luoyang 471023, Henan, China | [b] Information Engineering College, Henan University of Science and Technology, Luoyang 471023, Henan, China | [c] Luoyang Mining Machinery Engineering Design Institute, Luoyang 471039, Henan, China
Correspondence:
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Corresponding author: Wenshao Bu, Electrical Engineering College, Henan University of Science and Technology, Kaiyuan Road No.263, Luolong District, Luoyang 471023, Henan, China. E-mail:[email protected]
Abstract: Three-phase bearingless induction motor is a
multivariable, nonlinear and strong coupling object, to achieve its
decoupling control with high performance, an inverse system decoupling
control strategy based on air gap flux orientation is proposed. Under the
conditions of air gap flux orientation of torque system, the stator currents
of torque winding and suspension winding are taken as input variables, and
the inverse system mathematical model of bearingless induction motor is
established; adopting the inverse system method, the bearingless induction
motor is decoupled into four pseudo linear subsystems, include motor speed
first-order integral subsystem, air gap flux-linkage first-order integral
subsystem, α and β displacement components second-order
integral subsystems. The structure of decoupling control system is presented
also. From the simulation results, it is clear that not only the air gap
flux-linkage of torque system can be controlled accurately and directly, but
also the dynamic decoupling control between motor speed, air gap
flux-linkage of torque system and two radial displacement components can be
achieved; Meanwhile, the control system has the characteristics of small
overshoot and fast response speed.
Keywords: Three-phase bearingless induction motors, inverse system modeling, air gap flux orientation, decoupling control
