Design and Analysis of A Mechanical Flux-varying PM Machine with Auto-rotary PMs

Due to the constant magnetic field of the permanent magnet(PM) machine, its terminal voltage cannot be maintained constant as a generator [1], and the constant power area is narrow and the adjustable speed range is also limit as a motor [2]. In order to overcome these shortcomings, a new type of mechanical flux-varying PM machine with auto-rotary PMs (MFVPMM) is proposed in this paper. The operation principles of this machine presented are analyzed, and its flux weakening ability is studied by FEA.