Study On The Levitation Control System Of Bearingless Motor

Bearingless Motor has combined characteristics of motor and magnetic bearings. It is a new type motor which can implement electromagnet torque control and levitation force control all in the motor at the same time. Because of wide application prospect, now it has become a new hotspot in the field of high-speed AC driveThis dissertation researches bearingless motor and establishes the mathematical model of bearingless motor containing rotor eccentricity. It researches the air-gap field oriented induction-type bearingless motor system and control strategy of displacement levitation system, analysis causes of the levitation control coupling and proposes appropriate solutions. Final it establishes the bearingless motor control system. Its main tasks are:(1)Based on domestic and foreign developing status and research progress of bearingless Motor, according to its levitation principle, the mathematical model of radical levitation force containing rotor eccentricity is built. It provides a theoretical basis for control system design(2)According to strong coupling characteristic of bearingless motor, This dissertation researches bearingless motor control strategies based on the air-gap field oriented induction-type and UI identification of air-gap flux observer magnetic model levitation system control. It decouples suspension decoupled formula and establishes an independent suspension winding control strategy. It achieves mutual independence between torque control winding and suspension control winding in the control strategy.(3)Based on the levitation winding independent control strategy of U-I model, using MATLAB tools for building model and simulation, the simulation results can well proved the effectiveness of the control strategy.(4)A digital levitation control system is designed on DSP (TMS320LF240A). It provides reliable experimental conditions for bearingless motor levitation control.