Analysis Of Electromagnetic Field And Torque Control Of Flywheel Motor

Reaction Flywheel is an important executive component in the satellite attitude control system, it has been widely used in high precision satellite system for its favorable features of high accuracy in control, long life and flexible in using. Recently the micro-satellite is widely used in domains of communication, remote sensing, electron, reconnaissance for the characteristics of light weight, good performance, short development cycle and low cost. The micro-satellite is a significant trend in the aerospace area. To satisfy the demand of the micro-satellite's development, the attitude control system desire better flywheel motor. Aimed at saving energy as well as lightening weight of the micro-satellite, flywheel motor should be higher efficiency, lighter weight, and smaller volume. On the other hand, the torque of the flywheel motor should be calm so as to accurately control the attitude of satellite. In this thesis, the reaction flywheel motor which is the key component in reaction flywheel has been studied, the motor's structure is designed and the control strategy is studied.Firstly the flywheel motor's structure and its qualification are introduced, and then the transient field of the motor is calculated by the method of fixed time step. Basing on the result of calculation, the electromagnetic field of flywheel motor is designed. The parameter of magnetic circuit and winding are optimized, so as to reduce losses and heighten efficiency.The method of closed-loop current control is studied in torque control mode. The regenerative braking and plug braking are used to export reverse torque. Adding digital signal processor (DSP) into the control system, the circuit can be predigested and the torque skip can be reduced.Integrated the finite element software FLUX into the software MATLAB, precise model of driving and controlling system is build, using the method of ally calculation, the system of flywheel motor is calculated, the control strategy is validated by the results of the calculation.Finally the controller of flywheel motor is build with DSP. The experiment is done after the hardware and the software have been designed. The results of experiment indicate that the braking without skip can be achieved by using simple circuit. The precision can be enhanced for the calm output torque.