Kabushiki Kaisha Yaskawa Denki

Other

Shinichi Akimoto

Toshihiro Hanada

Hiroyuki Imayoshi

Mitsunori Sato

Keisei Inoki

Ryusuke Komiya

A power conversion device includes a power conversion circuitry configured to convert DC power into AC power by switching on/off a plurality of switching elements to switch each of a plurality of phase voltages to a voltage level selected from one of three levels including a first voltage, a second voltage higher than the first voltage, and a third voltage higher than the second voltage. A control circuitry is configured to control the plurality of switching elements so as to convert DC power into AC power without producing a combination of the first voltage and the third voltage between any two phases of the plurality of phase voltages.

Power conversion device with selective voltage control

A matrix converter includes a power converter circuit connectable on one side thereof with an alternating-current supply via a high-frequency filter and connectable on another side thereof with an alternating-current motor; a snubber circuit connected with a one-side line for connecting the high-frequency filter and the power converter circuit; a discharge switch discharging a charge accumulated in the snubber circuit depending on a voltage of the snubber circuit; and a control circuit configured to execute controlling the power converter circuit on the basis of a carrier frequency in test such that a test voltage is applied to the alternating-current motor, changing the carrier frequency in test on the basis of an operation state of the discharge switch, and determining constants of the alternating-current motor on the basis of a response state of the alternating-current motor at the time when the test voltage is applied.

Matrix converter and method for determining constants of alternating-current motor

There is provided an inverter device capable of simplifying the circuit structure, lowering the cast, and downsizing of the device. The inverter device detects a switching change of an inverter by a pulse and is equipped with a pulse signal detector capable of detecting a motor residual voltage or a phase and a detector for detecting a residual voltage or a phase. The inverter device includes a voltage detector, a circuit for detecting a pulse signal based on a comparison between a phase voltage detection value per one phase output from the voltage detector and a first reference voltage value, a circuit for detecting a line residual voltage based on phase voltage detection values of two phases output from the voltage detector, and a circuit for detecting a line phase based on a comparison between the line residual voltage and a second reference voltage value.

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Fukuoka, Japan

Shinichi Akimoto