Two-mode control strategy for BLDCM of magnetic suspended reaction flywheel

PID controller has the problems of inferior dynamic quality and bad anti-interference ability. However, Variable structure controller has the disadvantages of chattering and big steady-state error. A new controller combines variable structure and PID control method for brushless DC motor (BLDCM) of Magnetic Suspended Reaction Flywheel (MSRW) is designed. It is based on analyzing of the MSRW system and modeling on BLDCM. The variable structure controller and the PID controller are combined to make a quite high precision speed controller. The simulation results prove that the new controller has the advantages of chattering and steady-state error reduction, system dynamic response improvement, invariance to the disturbances compared with the variable structure controller and the PID controller. Furthermore, this new controller has the features of simplicity of design and implement, which will be important for realizing the high precision and high stability satellite attitude control.