Abstract: A permanent magnet motor is provided, including: a stator and a rotor. The stator has a plurality of windings. The rotor has a plurality of magnet placement slots and a plurality of air gaps. The plurality of magnet placement slots include a plurality of circumferential magnet placement slots circumferentially arranged and a plurality of radial magnet placement slots radially extending. The circumferential magnet placement slots and the radial magnet placement slots are circumferentially alternately arranged. The plurality of air gaps are adjacent to part of the plurality of magnet placement slots and distributed to be on a d-axis flux path of the rotor.

Abstract: A method is provided for controlling power generation. A control circuit is employed to control first and second switches of each of multiple switch groups of a drive circuit so that the first switches are kept in OFF state while the second switches are each switched between ON and OFF states at each given time point. With the second switches of the switch groups alternately switched ON/OFF, electrical power is fed to a circuit system, which includes a power storage device or an application device of loading.

Abstract: A rotor structure for a motor having built-in type permanent magnets includes a multiplicity of axial slots for containing the permanent magnet, and a shaft hole for installing a shaft. The invention essentially forms a petal-shaped convex polar portion having an exterior circular arc on the outer side of the rotor adjacent each axial magnet slot, where the radius of the circular arc is smaller than the radius of the rotor. The petal-shaped convex polar portions provide an approximately sinusoidal distribution of air-gap magnetic flux that can improve the cogging torque of the motor, weaken the armature reaction of the motor, and prevent the permanent magnets from being demagnetized. In addition, an axial empty slot is also provided between the shaft hole and the corners where the adjacent magnet slots approach such that the magnetic flux leakage can be prevented and the weight of the rotor can be reduced too.