Rotor Retaining Sleeve Design for a 1.12-MW High-Speed PM Machine

Fengge Zhang, Guanghui Du, Tianyu Wang, Guangwei Liu, Wenping Cao
2015 IEEE transactions on industry applications  
Permanent magnet synchronous machines (PMSMs) can provide excellent performance in terms of torque density, energy efficiency and controllability. However, PMs on the rotor are prone to the centrifugal force which may break their physical integrity, especially at high-speed operation. Typically, PMs are bound with carbon fiber or retained by alloy sleeves on the rotor surface. This paper is concerned with the design of a rotor retaining sleeve for a 1.12-MW 18-krpm PM machine; its
more » ... ; its electromagnetic performance is investigated by the 2D finite element method (FEM). Theoretical and numerical analysis of the rotor stress are carried out. For the carbon fiber protective measure, the stresses of three PM configurations and three pole filler materials are compared in terms of operating temperature, rotor speed, retaining sleeve thickness, and interference fit. Then a new hybrid protective measure is proposed and analyzed by the 2D FEM for operational speeds up to 22 krpm (1.2 times the rated). The rotor losses and machine temperatures with the carbon fiber retaining sleeve and the hybrid retaining sleeve are compared and the sleeve design is refined. Two rotors using both designs are prototyped and experimentally tested to validate the effectiveness of the developed techniques for permanent magnet machines. The developed retaining sleeve makes it possible to operate MW PM machines at high speeds of 22 krpm. This opens doors for many high-power high-speed applications such as turbo-generators, aerospace and submarine motor drives. Index Terms -Carbon fiber, finite element method, high speed mechanical stress, operation, retaining sleeve, permanent magnet machines. 0093-9994 (c)
doi:10.1109/tia.2015.2423659 fatcat:yywff3kdfbfvnnd7zmaqmprhme