Hitachi Astemo Ltd.

Hitachi Power Semiconductor Device, Ltd.

Daisuke Ikarashi

Kenji Kubo

Toru Masuda

Masamitsu Inaba

Yuji Takayanagi

Seiichi Hayakawa

Michihiro Asanuma

Provided are a reliable high-voltage system and a failure diagnosis method thereof, in which a vibration damping mechanism using an electrorheological fluid as a working fluid is a load, and can prevent electric shock due to leakage current and the influence on surrounding electronic devices. There are provided a first circuit that includes a power source and a ground, a second circuit that is magnetically coupled to the first circuit via a transformer and includes a load connected to the ground, a controller that is connected to the ground, a third circuit that is connected to the second circuit and the ground, a first resistor that is provided between a connection point at a high potential end of the second circuit and the ground, and a second resistor that is provided between a connection point at a low potential end of the second circuit and the ground, and has a resistance value different from a resistance value of the first resistor.

High-voltage system and failure diagnosis method for high-voltage system

The invention provides a gate drive device, a gate drive method, a power semiconductor module, and an electric power conversion device capable of reducing a negative gate surge voltage. The gate drive device drives a semiconductor device constituting an arm in an electric power conversion device. Before a turn-off start of a drive arm, in a counter arm, a voltage between one main terminal of the semiconductor device and a gate terminal of the semiconductor device is charged to a voltage value that is larger, in a positive direction, than a negative voltage of a negative gate power supply and smaller than a gate threshold voltage of the semiconductor device.

Gate drive device, gate drive method, power semiconductor module, and electric power conversion device

Growing community of inventors

Tokyo, Japan

Daisuke Ikarashi