Design Of The Drive Motor For A Magnetic-bearing Flywheel

Magnetic-bearing flywheels are new types of attitude control system of space vehicle. Based on the requirements of the magnetic-bearing flywheel drive system, one out-rotor and ironless armature permanent magnetic Brushless DC Motor (BLDCM) is proposed as its drive motor, focused on entity design, control system, power loss and temperature rise of the drive motor, this new architecture permanent magnetic BLDCM was studied systematically.The thesis focused on the special construction of the magnetic-bearing flywheel drive motor and the motor's fundamental electromagnetic relation was given. The magenetic circuit method was used to analyze its electromagnetic performance and the air-glap flux density of the motor was computed by the finite element method of 2-D electromagnetic field.Based on the application requirements of the magnetic-bearing flywheel's drive motor and according to the structure of double-closed-loop speed governing system, the conventional PID controller and the fuzzy controller were designed and simulated, and the simulated results were compared.According to the power loss calculation of the motor, the thermal circuit model of the stator armature was built. The eddy current loss of the motor winding and the temperature rise of the stator armature were analyzed.The raising speed experiment, the reduction of speed experiment and the temperature rising experiment were carried out by utilizing the magnetic-bearing flywheels experiment platform.The results of experiment show that the out-rotor, ironless armature permanent magnetic BLDCM could satisfy the demand of magnetic-bearing flywheels while is used as its drive motor. These virtues make it has promising application on spacecraft such as satellites.