Hitachi Industrial Equipment Systems Co., Ltd.

Sanyo Denki Co., Ltd.

Mutsuo Tokashiki

Hiroshi Watanabe

Kazuaki Tobari

Shigenori Miyairi

Yusaku Onuma

Takuya Sugimoto

Hisayuki Miyajima

The present invention achieves highly accurate control characteristics by estimating an induced voltage coefficient of a magnet motor without rotary auto-tuning. A first power Pc is calculated on the basis of the output voltage and output current of the magnet motor, and a second power P{circumflex over ( )} is calculated on the basis of the electric circuit constant, current command, output frequency, and induced voltage coefficient of the magnet motor. The induced voltage coefficient is estimated so that the calculated first power follows the second power, and the driving of the magnet motor is controlled in accordance with the induced voltage coefficient.

Power conversion device

A rotation control method of a synchronous motor, the motor comprising: a stator having AC windings thereround; and a rotor, being mounted within said stator, rotatably, wherein on an each surface, opposing to the rotor, of poles building up the stator, are formed plural numbers of teeth portions, and on a surface of the rotor, being made of permanent magnet, opposing to the poles of the stator, are also formed plural numbers of teeth portions, with a width being nearly equal to that of the teeth portion in a circumference direction thereof, and further AC voltages having a predetermined voltage-frequency characteristic is supplied to AC windings wound around the poles of the stator, and the AC voltages supplied from the inverter is so determined in the voltage-frequency characteristic thereof, at least within a part of frequency band equal or less than a predetermined rated frequency, a pull-out torque of the synchronous motor is equal to or greater that a rated pull-out torque at the predetermined rated frequency, thereby providing a synchronous motor and also an inverter to be used for such the synchronous motor, but hardly causing the step-out phenomenon in the operating condition when accelerating and decelerating the synchronous motor.

Synchronous motor and a rotation control method thereof, as well as, an inverter for use of the synchronous motor

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Sakura, Japan

Mutsuo Tokashiki