Design of a high efficiency generator/motor for flywheel energy storage system

The generator/motor is one of three key elements in a flywheel energy storage(FES) system, The objective of the flywheel system is the store and supply power in spacecraft applications and vehicles. Where a high speed brushless DC motor is chose. In high speed motor, the iron loss increases along with the alternant frequency of the magnetic field in the iron. A calculation model of iron losses of rotational permanentmotor is proposed, considering the influence of the rotation. The 2D time step finite element has been used for calculating a 20,000 r/min high speed permanent brushless DC motor, the loss density of deferent positions is proposed. Finally, the experimental measured value is compared with the computered one. The results prove the model is valid, which is the base of deeply optimization design forminishing the loss.