Composite sheath of high-speed permanent magnet generator with rotor strength constraint

摘要

Due to the high rotational speed, the permanent magnet of surface-mounted high-speed permanent magnet generator is easily damaged by the centrifugal force. So a high strength alloy sheath is installed to protect the permanent magnet. The material, thickness and eddy current loss of the composite sheath of the high-speed permanent magnet generator with rotor strength constraint is studied thoroughly in this paper. Generator rotor strength under different limit conditions is calculated by numerical analysis method based on the thick-cylinder theory of elastic mechanics. Various methods have been used to reduce the eddy current. The composite sheath of high-speed permanent magnet generator on the basis of rotor strength constraint is presented. Change of the material, thickness of each layer of the sheath is determined by calculation of stress and eddy current loss and optimized design of composite sheath with reasonable stress distribution and lower eddy current loss. Strength test of prototype rotor is carried out.