Design and Research on Hybrid Excitation Inductor Machine for Flywheel Energy Storage System

This paper presents a hybrid excitation inductor machine (HEIM) used in flywheel energy storage systems. The research content conducts theoretical analysis on the magnetic flux path and magnetic field regulation principle of hybrid excitation. The parameters of the special components of the hybrid excitation, namely the stator back iron and the field DC winding, were designed as required. Furthermore, the finite element calculation verification was carried out on the prototype, and the results were in line with the theoretical analysis. The proposed HEIM used in flywheel energy storage system has the ability to regulate magnetic flux by changing the excitation current. It can significantly reduce no-load losses and improve the energy storage efficiency of the flywheel on the basis of ensuring power density.