Fuji Electric Co., Ltd.

Fuji Electric Fa Components & Systems Co., Ltd.

Miwako Fujita

Ryu Araki

Michio Tamate

Tamiko Asano

Yuhei Suzuki

Takashi Kaimi

Tadanori Yamada

Hiroki Katsumata

Bao Cong Hiu

Yuta Sunasaka

The electromagnetic noise of a semiconductor device is conveniently evaluated, and the electromagnetic noise of an apparatus equipped with the semiconductor device is estimated. An evaluation method is provided which includes causing one of a first device and a second device of a semiconductor device to perform a switching operation, the semiconductor device comprising the first device and second device connected in series and a third device and a fourth device connected to each other in series and connected parallel to a series circuit of the first device and second device; measuring voltage variation occurring between the third device and the fourth device during the switching operation; and outputting an evaluation benchmark for electromagnetic noise of the semiconductor device, based on the voltage variation.

Evaluation method, estimation 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 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.

The present invention relates to a surge suppression circuit connected between an output end of an inverter INV and a cableto drive a motor M that is connected to the output end of the inverter INV via the cable, and relates to a motor drive system in which the surge suppression circuit is used. The surge suppression circuitincludes an inductance L and a resistor R connected in parallel with the inductance L. The resistor R is set so as to match, or so as to be less than, an impedance of zero-phase component of the cable. A surge suppression circuit and an inverter drive motor system are enabled to be applied to a low-voltage small-capacity inverter with no DC voltage neutral terminal, and enabled to reduce the zero-component of the surge voltage according to the connection to the output end of the inverter.

Surge suppression circuit and inverter drive motor system

A power conversion device including a power conversion portion that switches direct current voltage supplied by a positive line and negative line of a direct current power supply with a semiconductor switching element, and outputs converted voltage, is such that a plurality of interline capacitors are connected in parallel between the positive line and negative line, the capacitance of the plurality of interline capacitors is of a value that becomes smaller the nearer to the power conversion portion the position in which the interline capacitor is connected, and the capacitance of the interline capacitor with the smallest value of capacitance is set to a value greater than that of the capacitance between main electrodes when a direct current voltage is applied to the switching element used in the power conversion portion.

Growing community of inventors

Tachikawa, Japan

Miwako Fujita