Hitachi Automotive Systems, Ltd.

Hitachi Astemo Ltd.

Kouichi Yahata

Hideyuki Sakamoto

Teppei Hirotsu

Ryoichi Inada

Satoshi Hiranuma

Keiji Kadota

An object of the present invention is to provide a power conversion device capable of reliably discharging a voltage smoothing capacitor even when a circuit unit that outputs a discharge control signal fails. The power conversion device includes a voltage smoothing capacitor that is electrically connected in parallel with an inverter circuit unit, a discharge resistor that is electrically connected in parallel with the voltage smoothing capacitor, a switching element that is connected in series with the discharge resistor, a motor controller that selectively outputs a High-level signal and a Low-level signal as a discharge control signal, a switching signal circuit unit that outputs a rectangular wave signal having a predetermined duty, and a logic circuit that outputs any one of a rectangular wave signal having the same duty as the duty of the rectangular wave signal and a rectangular wave signal having a duty to the switching element based on the discharge control signal and the rectangular wave signal.

Power conversion device

An object of the present invention is to diagnose an abnormality detecting circuit that detects an abnormality, such as an overcurrent of a power semiconductor, with the number of insulating elements to be additionally provided, inhibited from increasing. There are provided: a drive circuit configured to output a gate signal to a power semiconductor; an abnormality detecting circuit configured to detect an abnormality of the power semiconductor; and a diagnosis signal applying circuit configured to apply a diagnosis signal to the abnormality detecting circuit. The diagnosis signal applying circuit applies the diagnosis signal, on the basis of the gate signal output by the drive circuit.

Driving device

Growing community of inventors

Hitachinaka, Japan

Kouichi Yahata