The Study Of Flywheel Battery’s Application In Electric Vehicles’ Power System

As a mechanical energy storage, flywheel batteries can be applied to many fieldsbecause of its many advantages. This thesis describes the charge and discharge controlof flywheel battery which is used in electric vehicles. In the acceleration of the vehicle,the flywheel battery discharges with chemical battery to provide peak power of the carrequired; When the car brakes, the flywheel battery charges with chemical battery toabsorb the feedback energy of the car.First, we briefly introduced the flywheel battery ang its development at home andabroad. Accroding to power demand characteristics of the car, the flywheel batteriesand accumulators composed of a composite power supply of electric vehicles. On thebasis of analysis of the flywheel battery’s charge and discharge model, the controlstrategy was made. To achieve the fast charging, the rotor field oriented vector controlstrategy was used to control flywheel battery’s motor. In order to get the stable DCvoltage in the discharge, the voltage loop and inner current loop strategy was used tofinish the rectifier control.Based on the theoretical analysis, the hardware and software of the flywheelbattery charge and discharge control system was designed. First, we introduced thecomponent selection of the main circuit. Using dsPIC30F3011as the control unit, thevoltage and current sensing circuit, the protection circuit and the photoelectric encodercircuit were designed. In software design part, flow chart and design thought of mainand subprogram was presented.Finally, the simulation and experiment were did. The results show that fast andstable flywheel battery charge and discharge control can effectively reduce the currentimpact of peak power in the electric vehicle battery. So the battery can be protected.