Fuji Electric Co., Ltd.

Honda Motor Co., Ltd.

Hiroki Katsumata

Tadanori Yamada

Ryu Araki

Michio Tamate

Miwako Fujita

Tamiko Asano

Yuhei Suzuki

Takashi Kaimi

Yuta Sunasaka

Bao Cong Hiu

Nobuhisa Ando

Masahiko Sato

Masakazu Gekinozu

Shinichi Yokoyama

A power conversion device includes a power converter to output AC power by converting input DC power, an electric leakage detector to detect electric leakage in a power supply line through which the AC power output by the power converter flows when the AC power is being output by the power converter, and a power conversion controller configured to control power conversion of the power converter. The power conversion controller is configured to stop power conversion operation of the power converter based on a detection result of the electric leakage detector.

Power conversion device

A power conversion device includes a power converter, a relay, and a welding detector. The welding detector includes a first resistor connected to a terminal of the relay on a first side, a capacitor and a second resistor, both of which are connected to a terminal of the relay on a second side, an application unit to apply an inspection signal to the relay via the capacitor and the second resistor, and a determiner connected between the capacitor and the second resistor, the determiner detecting a signal based on application of the inspection signal by the application unit to determine whether or not the relay is welded.

The radiated noise of a semiconductor device is conveniently evaluated, and the radiated noise of an apparatus equipped with the semiconductor device is estimated. An evaluation method including: making a semiconductor device that is connected parallel to a load by a load cable, perform a switching operation; measuring common-mode current flowing through the load cable during the switching operation; and outputting an evaluation benchmark for radiated noise based on the common-mode current, and an evaluation apparatus are provided.

Evaluation method, combined evaluation method, evaluation apparatus, and combined evaluation apparatus

The radiated noise of a semiconductor device is conveniently evaluated, and the radiated noise of an apparatus equipped with the semiconductor device is estimated. An evaluation method and an evaluation apparatus are provided, including: causing a semiconductor device to perform a switching operation; measuring voltage variation occurring between main terminals of the semiconductor device during the switching operation; and outputting an evaluation benchmark for radiated noise of the semiconductor device based on the voltage variation. The outputting the evaluation benchmark may include calculating the voltage variation in the semiconductor device for each frequency component as the evaluation benchmark.

Evaluation method, estimation method, evaluation apparatus, and combined evaluation apparatus

A motor drive device includes a bridge circuithaving a plurality of legs with switch elementsin upper and lower arms. High frequency AC voltage output from the bridge circuit, when it is connected to an AC power supply, is converted into a DC voltage via a transformerand an AC/DC conversion circuit, thus charging the battery. Also, the DC voltage of the batteryis converted into an AC voltage by the bridge circuitwhen the AC power supplyis cut off from the bridge circuit, and supplied to the alternating current motor. Because of this, the isolating transformercan be driven at high frequency while the motor driving power conversion circuit is also used for battery charging, and a reduction in size and reduction in cost of the overall device are achieved.

Motor drive device

A power factor correction circuit includes a rectifier that rectifies AC power supply voltage, a series circuit of an inductor and a semiconductor switch connected between the rectifier circuit output terminals, and a series circuit of a diode and a smoothing capacitor connected to both ends of the semiconductor switch, a load connected to both ends of the smoothing capacitor, so that the power factor on the input side of the rectifier circuit is corrected by the switching operation of the semiconductor switch. This power factor correction circuit includes a control circuit that controls the switching frequency of the semiconductor switch such that the switching frequency becomes maximum when the ripple of a current flowing through the inductor becomes maximum. According to this power factor correction circuit, normal mode noise can be reduced, and the size of a filter circuit can be decreased.

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Hino, Japan

Hiroki Katsumata