The Implementation Of The Drive And Control Of Variable Speed Flywheel System

The attitude control actuator which based on the principle of momentumexchange has been one of the key technologies in the spacecraft development. Takingthe background of the applications of spacecraft attitude control, the drive andcontrol on variable speed flywheel system, which was used in the variable speedcontrol moment gyro (VSCMG) and the Gyrowheel, was analyzed in this thesis. Themotor servo control system need to realize high precision steady speed control, whileat the same time can work within a scope of the speed. To realize the functionmentioned above, phase-locked loop servo control method was used for the motordriving servo system of the variable speed flywheel system.First of all, a mathematical model of the brushless DC motor for the variablespeed flywheel system was established, it was a two-order model. The structure ofthe phase-locked loop servo system is analyzed, that the ten-state PFD was betterthan the common three-state PFD. It also analyzes the different types of the loopfilter function, according to the different types of the PLL system. It was widelyknown that the traditional PLL servo system can only realize the steady speed control.So the three types PLL has been come up with to realize the steady speed andvariable speed control, the dual phase-locked loop control method which based onthe feed forward control was researched at the same time. Two differentmathematical modeling were established for the different control methods and theMatlab simulations have been finished for these two methods.Then, based on the mathematical model mentioned above, two differenthardware circuits based on the phase-locked loop technology have been designed forthe realization of steady speed control and variable speed control of the brushless DCmotor. Three types phase-locked loop system uses the Application SpecificIntegrated Circuits for PFD, integrated operational amplifier for the loop filter, andthe Pulse width modulation chip to generate the PWM signal. The dual-loop PLLsystem used the programmable logic devices FPGA which included the dual-PFD,loop filter, active feedback and the PWM generator blocks to realize the function.Finally, some experiments have been carried out according to the two differentdesign plans. It is proved that these two systems can realize motor steady speed andvariable speed control. Both of them can be used in the implementation of the driveand control of variable speed flywheel system.