Kabushiki Kaisha Yaskawa Denki

Hideaki Iura

Shinya Morimoto

Akira Yamazaki

Kozo Ide

Yoichi Yamamoto

Shingo Fukumaru

Hirofumi Kinomura

Mitsujiro Sawamura

Takahiro Saeki

Shigekazu Nakamura

Shuji Matsuda

Takayuki Shiota

Keisei Inoki

Masanobu Inazumi

Toshihiro Hanada

Kazuhiko Hiramatsu

Sadayuki Sato

Tomohiro Kawachi

Satoshi Sueshima

Katsushi Terazono

Yoshiyasu Takase

Shoji Konakahara

Kazuhiro Nonaka

Shuichi Fujii

Yuichi Terazono

Tohru Kai

Yoshiaki Yukihira

Kengo Nakahara

A power conversion apparatus includes a power converter circuit that outputs an AC power to an electric motor, and circuitry that controls the power converter circuit to add a first change, accompanying a change of a power generated by the electric motor, to a first phase angle, which is a phase angle of a magnetic flux direction of the electric motor corresponding to the AC power, extracts a component generated by the first change from first information indicating the electric power supplied to the electric motor, and estimates the power generated by the electric motor based on the component.

Power conversion apparatus, power estimating method for electric motor, and control method for electric motor

A power conversion apparatus includes: a power converter that includes a plurality of switching elements; and a controller that controls the plurality of switching elements. The controller includes: a command generator that generates a voltage command vector; a synthesizer that synthesizes a correction vector with the voltage command vector to generate a synthetic vector; an adjuster that adjusts an output time of a plurality of voltage vectors from the power converter, the output time being corresponding to the synthetic vector; and a correction vector generator that generates the correction vector on the basis of an adjustment result of the adjuster.

Power conversion apparatus, control apparatus, and control method using a correction vector

A power conversion apparatus includes: a power converter that includes a plurality of switching elements; a switch controller that controls the plurality of switching elements so that the order of outputting a plurality of kinds of voltage vectors from the power converter is opposite in a first half and a latter half of a carrier period; a DC-side current detector that detects a DC-side current of the power converter; and a phase current detector that detects one phase current among three phase currents on the basis of the detected DC-side current at a detection timing, the detection timing being selected from a first-half timing and a latter-half timing of the carrier period at which the same kind of voltage vector is output. The phase current detector includes a timing switcher that alternately switches the detection timing between the first-half timing and the latter-half timing.

Power conversion apparatus, phase current detection apparatus, and phase current detection method

A motor control apparatus includes a voltage regulator to execute a voltage increase mode to increase a voltage applied to an induction motor from a lower limit of a first range over time. A frequency regulator executes a frequency decrease mode to decrease a frequency of the voltage from an upper limit of a second range over time. The frequency regulator limits decrease of the frequency when a bus voltage of a bus exceeds a first threshold in the frequency decrease mode. The bus supplies DC power to an inverter to drive the motor. A mode changer alternatively changes the voltage increase mode and the frequency decrease mode to control the motor to change from a free running state to a state in which the voltage and the frequency satisfy a relationship. The determinator determines whether the voltage and the frequency satisfy the relationship.

Motor control apparatus and method for controlling motor

A motor control apparatus includes a voltage regulator to execute a voltage increase mode to increase a voltage applied to an induction motor from a lower limit of a first range over time. A frequency regulator executes a frequency decrease mode to decrease a frequency of the voltage from an upper limit of a second range over time. When a current through the motor exceeds a first threshold in the voltage increase mode, a mode changer changes the mode to the frequency decrease mode. When the current through the motor becomes smaller than a second threshold in the frequency decrease mode, the mode changer changes the mode to the voltage increase mode to control the motor to change from a free running state to a state in which the voltage and the frequency satisfy a relationship. A determinator determines whether the voltage and the frequency satisfy the relationship.

A controlling apparatus for an electric motor according to an embodiment includes a superposed component generator, an inverter, a current detector, and a magnetic pole position estimator. The superposed component generator generates, at a predetermined cycle, a superposed voltage reference of which vector is shifted by 90 degrees with respect to that of a superposed voltage reference previously generated, in a coordinate system that is set to a stator of the electric motor. The inverter outputs a driving voltage that is based on a driving voltage reference superposed with the superposed voltage reference to the electric motor. The current detector detects currents flowing into respective phases of the electric motor, and outputs the detected currents. The magnetic pole position estimator detects the magnetic pole position of the electric motor based on an amount of change in the detected currents at the predetermined cycle.

Magnetic pole position estimating apparatus for electric motor, controlling apparatus for electric motor, and magnetic pole position estimating method for electric motor

A power regenerative converter includes: a power conversion unit configured to convert AC power supplied from an AC power supply into DC power and convert DC power into AC power to be supplied as regenerative electric power to the AC power supply; an LCL filter including a reactor unit having a plurality of reactors connected in series between the power conversion unit and the AC power supply, and capacitors each having one end connected to a series connection point of the reactors in the reactor unit; a drive control unit for controlling the power conversion unit based on an AC voltage command; and a voltage command compensation unit for calculating a compensation value in accordance with a capacitor voltage being a voltage at the series connection point of the reactors and adding the compensation value to the AC voltage command input to the drive control unit.

Power regenerative converter and power conversion apparatus

A controller of an AC motor includes a d-axis voltage command section to generate a d-axis voltage command on a d axis of a d-q coordinate system. A d-axis non-interactive control section removes, from the d-axis voltage command, an interference component resulting from a current on a q axis of the system. A first current deviation arithmetic section obtains a deviation between a current command on the q axis and the current on the q axis flowing through the AC motor. A q-axis integral control section outputs an integral value of the deviation. A q-axis voltage command section generates a q-axis voltage command based on the deviation. A constant output control section outputs a correction voltage command based on the integral value. A d-axis voltage command correction section subtracts the correction voltage command from the d-axis voltage command after non-interactive control to correct the d-axis voltage command.

Controller of AC motor

A motor control apparatus according to an embodiment includes a power conversion unit and a control unit. The power conversion unit supplies power to a motor having salient pole characteristic. The control unit performs proportional-integral control on the deviation between a current reference and a current flowing into the motor to generate a voltage reference, and controls the power conversion unit on the basis of the voltage reference. The control unit estimates the magnetic-pole position of a rotor of the motor on the basis of a high-frequency current flowing into the motor by controlling the power conversion unit, and corrects the estimated magnetic-pole position on the basis of an integrated value of the proportional-integral control.

Motor control apparatus and magnetic-pole position estimating method

A motor control apparatus according to the embodiment includes a rotational position estimating unit, a change amount estimating unit, and an inductance estimating unit. The rotational position estimating unit estimates a rotational position of a rotor from a motor parameter including a q-axis inductance of a motor on a basis of an output current to the motor and a voltage reference. The change amount estimating unit estimates a change amount of an output torque with respect to a current phase change of the motor corresponding to a high frequency signal whose frequency is higher than a drive frequency of the motor. The inductance estimating unit estimates an inductance value that obtains a maximum torque on a basis of the change amount as the q-axis inductance.

Motor control apparatus and motor control method

A power regeneration apparatus includes a power conversion unit, an AC reactor, a voltage detecting unit, a phase detecting unit, a drive control unit for controlling the power conversion unit based on a phase detection value, and a reactive current component detecting unit. The phase detecting unit detects the phase of the AC power supply. The reactive current component detecting unit detects a reactive current component of a current. The drive control unit includes a phase correction section. The phase correction section corrects the phase detection value based on the reactive current component.

Power regeneration apparatus and power conversion apparatus

An alternating-current motor control apparatus includes a stator frequency computing unit configured to compute a stator frequency of a motor magnetic flux; a torque error computing unit configured to compute a torque error by using the motor magnetic flux, an estimated current, and a motor current; and a speed estimator configured to estimate a speed of the alternating-current motor by using the stator frequency and the torque error. The speed estimator includes a proportional controller configured to reduce the torque error to zero, and an adaptive filter configured to eliminate a high-frequency component of the torque error.

Alternating-current motor control apparatus

A control device includes a slip calculator that calculates a first slip frequency of an induction motor, a current detector that detects motor current that passes through the induction motor, an adder that calculates a primary frequency by adding a speed command and a second slip frequency that are given, a command voltage generation unit that generates first command voltage from the primary frequency, a voltage error observer unit that estimates a command voltage error from the first command voltage and the motor current, a slip correction unit that calculates a slip correction amount from the command voltage error, an adder that calculates the second slip frequency by adding the first slip frequency and the slip correction amount, and a voltage error correction unit that corrects the first command voltage using the command voltage error and outputs second command voltage.

Control device for induction motor

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

A voltage type inverter apparatus comprising a voltage correcting portion. The voltage correcting portion corrects a given voltage instruction based on a value generated by passing a direct current bus voltage detected value through a first degree delay filter. In decelerating a speed of the alternating current motor, the speed is decelerated in an overexcited state by multiplying the given voltage instruction by a set gain. Simultaneously, a time constant of the first degree delay filter is made larger than a time constant in a normal control state.

Growing community of inventors

Kitakyushu, Japan

Hideaki Iura