Kabushiki Kaisha Yaskawa Denki

Jun Oyama

Kozo Ide

Mitsujiro Sawamura

Toshihiro Sawa

Mengesha Mamo Wogari

A control device is provided for a synchronous motor, which drives the synchronous motor through a voltage operated PWM inverter and controls a torque and a speed of the motor, including a unit for causing a PWM carrier signal to have an arbitrary phase difference between two phases such UV, VW, or WU in three phases of U, V, and W, a unit for extracting a high frequency voltage and a high frequency current, which are thus generated from a detecting voltage or a command voltage and a detecting current, and a unit for estimating a position of a magnetic flux or position of a magnetic pole by using the high frequency voltage and the high frequency current which are excited.

Control device for synchronous motor

It is an object of the invention to provide an apparatus for estimating a magnetic pole position of a motor in which the amplitudes of high-frequency currents can be adjusted. In the invention, a controlling apparatus for driving a motor (-) by a voltage source PWM inverter (-), and controlling a torque and speed, or torque, speed, and position of the motor has: means for switching over first means for producing an arbitrary phase difference in PWM carrier signals between respective two phases such as UV, VW, or WU of three or UVW phases, and second means for causing the phase difference between two phases such as V, VW, or WU of three or UVW phases to become zero; means for extracting high-frequency currents in a same frequency band as carrier signals generated by it, from estimated currents; and means (-) for estimating a magnetic pole position by using the extracted high-frequency currents.

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Nagasaki, Japan

Jun Oyama