Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.