New Approach for Pole-Changing With Dual-Memory Machine

Memory machines possess the ability of memorizing magnetization level on their permanent magnets (PMs) and hence provide flexible flux-tuning without using the dc field winding for continual excitation. In this paper, two kinds of memory machines, namely the dual-memory and single-memory, are investigated for pole-changing operation with emphasis on the new pole-changing approach for the dual-memory machine. In essence, the dual-memory machine realizes the pole-changing by dropping some poles whereas the single-memory one achieves the pole-changing by reversing some poles. The finite element analysis validates the proposed pole-changing approaches.