The application of flywheel energy storage device is limited owing to its complex structure, high cost and low reliability of magnetic bearings. This paper presents a novel topology structure of the stator excitation solid rotor machine (SE-SRM) for flywheel energy storage system, which integrates flywheel, motor and axial magnetic bearing, with the advantages of high integration, compact structure and high reliability. Firstly, the basic structure and work principle of the SE-SRM were introduced. Secondly, because of the complex geometry of the motor, which is difficult to design and optimize through finite element directly, the magnetic network model was established for modeling and analyzing to improve the design efficiency, and a new method for solving the Carter’s coefficient for sinusoidal slot rotors was proposed. Finally, the results of finite element model and no-load experiment of prototype were compared and analyzed, and the correctness of the magnetic network model is proved.

Carter’s coefficient, flywheel energy storage system, magnetic network model, sinusoidal slot rotor, solid rotor