A Novel Dual-Winding BLDC Generator-Buck Converter Combination for Enhancement of the Harvested Energy From a Flywheel

This paper proposes a novel flywheel energy storage system which results in up to 20% enhancement in the harvested energy from the flywheel, in comparison with the existing schemes. Generally, boost converters are used for boosting the voltage in such systems. Major limitation of a boost converter is the dependency of its maximum achievable voltage gain on the ratio of its source resistance to load resistance which limits the amount of harvested energy from a flywheel and lowers the efficiency at low input voltages. The proposed scheme uses a novel and unique combination of dual armature winding permanent-magnet brushless dc machine and a buck converter to maintain the dc-bus voltage to overcome the limitations of the boost converter. Further, the new scheme helps in reducing the armature current loading on the machine to a large extent when it is being used as a generator. A detailed study has been carried out and the effect of generator winding configurations and control strategies adopted in the proposed scheme are analyzed. The proposed scheme is simulated using MATLAB/SIMULINK software. A hardware prototype having 1.0 kW/200 V rating has been built. The theoretical and experimental results are found to be in agreement