Novel Dual-rotor Single Stator Coreless Permanent Magnet Machine with Dual-flywheel

Permanent magnet (PM) machine has attracted much attention in the field of flywheel energy storage system (FESS) due to its merits of high power density and high efficiency. However, the flux generated by the PM would cause large stator core loss during the idling state of FESS, which would reduce the energy conversion ratio and limit the application of FESS in long-term energy storage occasions. Addressing this issue, a novel dual-rotor single stator coreless permanent magnet machine (DSSCPMM) with dual-flywheel is proposed in this paper. The stator of the DSSCPMM is made of ceramic material, which can effectively eliminate the stator core loss. The rotor of the DSSCPMM contains inner and outer rotors, which are used as the flywheels and can be helpful to improve the energy storage density. Firstly, the structure and operation principle of the proposed DSSCPMM are illustrated. Then, the influences of the key structure parameters and arrangement of PMs, winding configurations, and magnetization method on the electromagnetic performance of the proposed DSSCPMM are investigated. Finally, the optimized structure of the DSSCPMM is obtained and the efficiency is calculated. The result shows that the proposed DSSCPMM is a promising candidate for the application of FESS.