Abstract of Thesis presented at COPPE/UFRJ as a partial fulfillment of the requirements for the degree of Master of Science (M.Sc.)

Bearingless Motor with DSP Control

Rafael Ramos Gomes

March/2007

Advisors:

Richard Magdalena Stephan José Andrés Santisteban Larea

Department:

Eletrical Engineering

      Bearingless motor is a device with axial positioning and rotational purposes, combining in a single electromagnetic package the functions of magnetic bearings and motor. Position measurement is continuously necessary in order to guarantee the operation of a feedback control system that produces the required axial forces.
      Two PID control loops, actuating on orthogonal directions, are used to stabilize each shaft end. Based on a mathematical model, the system behavior was studies through numerical simulations at several operating speeds.
      Due to the gyroscopic effect, there is a coupling between the orthogonal directions that increases with the angular velocity. This fact suggests a scheduled PID adaptive controller, which parameters change according to the rotor speed.
      This work presents a bearingless motor control system implemented with the help of a fixed-point Digital Signal Processor (DSP). A methodology for the determination of the scheduled adaptive control parameters is given. Besides the control system for radial positioning, a speed control was implemented.
      A laboratory prototype is used as platform for experimental tests.