Fuji Electric Co., Ltd.

Hideki Oguchi

Akio Toba

Toshiharu Mochida

Hitoshi Nakazono

Hiroshi Shimada

Kenichi Mae

Makoto Terajima

Takeyuki Kobayashi

Provided is a variable magnetic flux-type permanent magnet rotary electric machine wherein a leakage magnetic flux leaking from a certain permanent magnet included in the rotor core to a permanent magnet circumferentially adjacent on either side of the certain permanent magnet is controlled by q-axis current and thereby a magnetic flux emanating from the certain permanent magnet and linking with the armature coil wound on the stator is controlled without forming a mechanically weak part in the rotor core.

Variable magnetic flux-type permanent magnet rotary electric machine

Magnetic flux short-circuit preventing slits extend from opposite ends of two permanent magnets in an outer circumferential surface of a rotor toward a center of a magnetic pole. Grooves formed in the outer circumferential surface can be located at a distance from each other symmetrically with respect to the center of the magnetic pole and at a distance from a groove of an adjacent magnetic pole in the outer circumferential surface. Relations are established as &#x3b8;f=n&#xd7;&#x3c4;s and &#x3b8;s=n&#xd7;&#x3c4;s where &#x3c4;s designates a pitch of stator winding slots, which pitch is converted into an angle around a rotation center, &#x3b8;f designates an angle between the magnetic flux short-circuit preventing slits, &#x3b8;s designates an angle between the grooves, and n designates a predetermined integer. Thereby, a permanent magnet-embedded type rotary electric machine in which the influence of a manufacturing error can be minimized so that cogging torque can be reduced stably.

Permanent magnet-embedded type rotary electric machine with rotor having slots and rotor surface grooves

A controller for switching an inverter includes a current detecting unit, an overcurrent level determining unit which determines an overcurrent level for stopping the inverter in accordance with a value corresponding to the number of revolutions of a motor, a current comparing unit which compares a detected output current value of the inverter with the overcurrent level, and a gate signal generating unit which generates a signal for turning off all semiconductor switching devices of the inverter when the current comparing unit makes a determination that the detected output current value has reached the overcurrent level. The overcurrent level is lowered as the number of revolutions of the motor increases.

Power conversion apparatus

Growing community of inventors

Hino, Japan

Hideki Oguchi