Influence of Magnetic Structure on Electromagnetic and Dynamic Properties for LPMBLDCM

Linear permanent-magnet brushless dc motor (LPMBLDCM) has the advantages of high flux density, high energy efficiency, simple structure, and other characteristics, which are suitable for high speed and high thrust applications. It is also used as an electromagnetic catapult to be applied to small- and medium-sized aircraft launches. This paper focuses on the influence of magnetic structure on electromagnetic and dynamic performance of a moving magnet type LPMBLDCM. Three magnetic structure candidates are presented, including the serial magnetic structure, parallel magnetic structure, and the Halbach magnetic structure. The dynamic process of LPMBLDCM is analyzed by a Maxwell-2-D transient solver for each magnetic structure. The influences of magnetic structure on the air-gap flux density, on the back electromotive force, and on the mover velocity and thrust output are analyzed. The electromagnetic characteristics and dynamic performance for three magnetic structure LPMBLDCMs are contrasted. This paper follows previous works in which some relevant experiments were also executed. Simulated and measured results can provide useful references to optimized design and prototype matching for an electromagnetic catapult.