Kabushiki Kaisha Yaskawa Denki

Other

Masanobu Inazumi

Ryuichi Oguro

Shinya Morimoto

Hideaki Iura

Kozo Ide

Seung-Ki Sul

Young Doo Yoon

Shuichi Fujii

Masanori Kawatani

Noriaki Sueyoshi

An alternating-current motor control apparatus includes a voltage controller configured to output a command voltage vector so that the command voltage vector is time-averaged for time periods, a square-wave voltage generator configured to control, every time period, amplitudes and phases of voltages to be applied to an alternating-current motor, a current detector configured to detect motor currents at a timing synchronized with periods 1/N-th of the time periods, where N is equal to or larger than one, a coordinate transformation section configured to perform coordinate transformation to transform the motor currents into two-phase currents, an envelope extractor configured to extract two-phase currents as waveforms having amplitudes that periodically change from the two-phase currents, and extract envelopes of the waveforms, and a magnetic-pole-position computing section configured to compute a magnetic-pole position using the envelopes.

Alternating-current motor control apparatus

There is provided an electromechanical machine control system for variable speed controlling an electromechanical machine which can realize a desired control response and a stable control system by online regulating the gain of a linear differential controller by current feedback based on an electric parameter or mechanical parameter of the electromechanical machine. The electromechanical machine control system includes a current coordinate transformer () for coordinate transforming a current detection value of the electromechanical machine () which is inputted into a &#x3b3;-axis current having the same phase as a position reference and a &#x3b4;-axis current which advances 90 degrees further than the position reference, a &#x3b4;-axis stabilizer () for implementing a linear differential control on the &#x3b4;-axis current which is inputted to output a &#x3b4;-axis current voltage correction amount and a &#x3b4;-axis stabilizing gain regulator () for regulating the linear differential control gain of the &#x3b4;-axis stabilizer.

Electromechanical machine control system

An induction motor control device includes an inverter circuit for driving an induction motor by outputting a command voltage, a current detector for detecting an output current, a magnetic flux estimation observer for generating an estimated magnetic flux, an estimated current, and a phase command for the motor using the command voltage and the output current, a primary angular speed estimator for estimating a primary angular speed using the estimated magnetic flux, a slip compensator for calculating a slip angular frequency using the output current, a first angular speed estimator for estimating a first angular speed using the primary angular speed and the output current, a second angular speed estimator for estimating a second angular speed using the output current, the estimated magnetic flux, and the estimated current, and a resistance estimator for estimating a secondary resistance value of the motor using the first and second angular speeds.

Induction motor control device

This invention provides an inverter device that can detect a step-out state of an AC motor by a simple process without depending on a rotation speed of the AC motor and also surely hold an abnormal state in the step-out state of the AC motor. The inverter deviceincludes a torque current control unitfor controlling a torque current direction voltage so that a given torque current command value coincides with a torque current detection value, and a V/f conversion unitfor calculating an induced voltage command of the AC motorbased on a given output frequency command. The inverter device further includes a step-out detection unitfor detecting a step-out state of the AC motorbased on the torque current direction voltage and the induced voltage command.

Inverter device

In sensorless vector control performed through use of a rotation speed of a synchronous motor 6 and the position of a rotor, a positive current is caused to flow to a &#x3b3; axis on the assumption that a 'd' axis serving as a true magnetic axis is out of phase with the &#x3b3; axis by only an angle of load &#x3b8;e, whereby torque which is proportional to i&#x3b3; sin &#x3b8;e and directed toward the &#x3b3; axis arises in the magnetic axis. Accordingly, a deviation between a d-q axis serving as a true magnetic axis and a &#x3b3;-&#x3b4; axis serving as a control axis is eliminated. Even if load is exerted on the motor, the &#x3b3; axis serving as a control axis is constantly aligned with the 'd' axis serving as the magnetic axis of the synchronous motor, thereby enabling excellent vector control.

Method of controlling speed of synchronous motor, and method of identifying constant of synchronous motor

A magnetic flux estimatorof a controller used for sensorless vector-controlling of an induction motor computes an estimated speed &#x3c9;and an estimated phase &#x3b8;from input &#x3b1;-phase and &#x3b2;-phase voltage instructions V*, V* and &#x3b1;-phase and &#x3b2;-phase currents i, i. A speed correctorreceives these information items and determines a difference between a differential value output from a phase estimator and an additionally input slip angular speed; that is, a deviation &#x3c9;'. Further, a primary delay integral value is determined by subtracting a slip angular frequency &#x3c9;from the deviation, and the primary delay integral value is multiplied by a correction gain, to thereby produce a correction to be made on the estimated speed &#x3c9;. Thus, a more accurate estimated speed &#x3c9;&#x2033;is obtained.

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Kitakyushu, Japan

Masanobu Inazumi