energy storage system

YAO Yang，FANG You-tong，DONG Fan，ZHANG Jian-cheng，HUANG Xiao-yan，ZHANG jian

（School of Electrical Engineering，Zhejiang University，Hangzhou 310027，China）

Abstract：In order to solve the problem of surface mounted permanent magnet machine（SPM）running in the high speed situation，for the rotor design of the high speed motor/generator（M/G），motor strength and eddy current loss were analyzed.With a 80 kW high speed surface mounted brushless permanent magnet（PM）DC machine in the flywheel energy storage system（FESS），analytical method was adopted to study the relation between protective sleeve thickness，interference fit and rotor mechanical properties.The effects of the stator

slot width，air gap length，and sleeve thickness to the rotor eddy current losses were carried out，which indicated that reducing the stator slot width or sleeve thickness and increasing air gap length could reduce rotor eddy current loss. With orthogonal analysis，a set of optimizedrotor solution was given under the premise of ensuring the strength witch could improve material utilization and reduce loss. The finite element method（FEM）was adopted to validate the design. The result indicate that the design is reasonable and reliable to meet the design requirements.

Key words：strength analysis；eddy current loss；rotor design；orthogonal analysis