Research on Electromagnetic System of Large Capacity Energy Storage Flywheel

A large capacity and high-power flywheel energy storage system (FESS) is developed and applied to wind farms, focusing on the high efficiency design of the important electromagnetic components of the FESS, such as motor/generator, radial magnetic bearing (RMB), and axial magnetic bearing (AMB). First, a axial flux permanent magnet synchronous machine (AFPMSM) based on soft magnetic composite (SMC) material is designed. Then, considering the structure of FESS and machine, a permanent magnet biased RMB (PMRMB) and a HALBACH axial passive magnetic bearing (PMB) are proposed, which have the advantages of low power consumption and large bearing capacity; then, the analyses are carried out according to the load capacity requirements. Finally, the flywheel prototype is fabricated and tested. The experimental results verify the relevant theoretical analysis and finally can achieve stable and reliable operation.