Proposal of electrically reversal magnetic pole type variable magnetic flux PM motor

This paper describes a variable magnetic flux PM motor in which space harmonic power is utilized for the magnetic flux weakening, automatically. The stator has a toroidally-concentrated winding structure, and the torque generation surfaces are composed of three air-gaps which are single radial-gap and double axial-gaps. The radial-gap rotor is a consist-magnetized PM rotor and the axial-gap rotors are self-excited wound-field rotor. The axial-gap rotor can retrieve a space harmonic power, which is inevitably generated by a concentrated winding structure, for magnetomotive force. A mechanical design of the prototype is revealed, and the operation principle of the automated-magnetic flux weakening is clarified through the FE-analysis. In addition, actual prototype machine is introduced. Consequently, the effect of automated-armature line voltage decrease is investigated with respect to rotation speed increase.