Kabushiki Kaisha Yaskawa Denki

Tsuyoshi Higuchi

Kenji Yamada

Aiko Inuduka

Katsutoshi Yamanaka

Sadao Ishii

Takashi Kuboyama

Yutaro Ihara

An electric power converter according to an embodiment includes a switching unit, a controller, and a second bidirectional switch. The switching unit includes a plurality of first bidirectional switches disposed between a DC power source and an AC load or between a DC load and an AC power source. The controller controls the switching unit to perform power conversion between DC power and AC power. When turning off the second bidirectional switch disposed on a path between one pole of the DC power source or the DC load and the switching unit, the controller turns on the first bidirectional switch connected between the other pole of the DC power source and the AC load or between the other pole of the DC load and the AC power source.

Electric power converter and control method for electric power converter

A motor drive system includes: a three-phase motor; a power conversion device that supplies power for driving the three-phase motor; and an output filter that is arranged between an output of the power conversion device and the three-phase motor and has a configuration in which a setting value of a filter resonance frequency is selectable and changeable.

Output filter and motor drive system including the same

Provided are an output filter and a power conversion apparatus having such an output filter. The output filter is configured by a neutral point detector with a reduced size and having no common mode inductance occurring by making inductances in coils of respective phases equal.

Output filter and power conversion apparatus having the same

A power converter includes: a determination section which, prior to an actual operation, determines presence/absence of a common mode filter connected to a line for supplying power to a motor, switching elements being driven with a predetermined PWM on/off drive signal corresponding to a carrier frequency prior to the actual operation; and a PWM control method changing/setting section which, during the actual operation, changes and sets a PWM control method in accordance with a result of the determination of the presence/absence of the common mode filter.

Power converter

An output filter includes a polyphase common-mode filter having a polyphase common-mode choke connected to an output of a power converter at one end, a first polyphase capacitor connected to the other end of the polyphase common-mode choke at one end, and a neutral-point detecting transformer connected to the other end of the first polyphase capacitor at one end; a capacitor/resistor series-connected body connected to a frame ground of the power converter at one end and connected to the other end of the neutral-point detecting transformer at the other end; and a polyphase normal-mode filter having a polyphase normal-mode choke connected to the other end of the polyphase common-mode choke at one end, and a second polyphase capacitor connected to the other end of the polyphase normal-mode choke at one end and having the other ends connected together and further connected to the one end of the capacitor/resistor series-connected body.

Growing community of inventors

Fukuoka, Japan

Tsuyoshi Higuchi