Axial excited hybrid reluctant motor applied in electric vehicles and research of its axial coil signal

Characteristics of traction motors for electric vehicles (EV) should be high power density and high efficiency over the whole working area. The axial excited hybrid reluctant motor is fit for the EV application. In the motor, there are three excitation sources, which are permanent magnetic, armature, and axial coils. Controlling these excitation sources will make the motor run in different modes, which satisfy many kinds of conditions of the vehicle. With special structure and electromagnetic design, the electromagnetic torque includes reluctant torque, and the torque per unit volume is improved. Controlling the axial coil current will adjust the main flux. Then the flux weaken control is convenient achieved. When it is used as generator, main flux can be adjusted. The axial coil can also be used as position sensor. The electromotive force signal denoting the rotor position is added on the dc voltage applied on the axial coils. The paper introduces the structure and principle of the axial excited hybrid reluctant motor and resolves the electromagnetic torque. The axial magnetic field is analyzed. And the relation of the emf of the axial coils with the rotor position is produced. The simulation and experiment are made. The result shows that characteristics of this novel type motor satisfied the demands of the traction motor for EV.