Nippon Steel & Sumitomo Metal Corporation

Toshiba Mitsubishi-electric Industrial Systems Corporation

Masashi Fukuda

Hiroyuki Okada

Kunio Hayashi

Riki Okamoto

Nobuhiro Fujita

Hirokazu Taniguchi

Toshimasa Tomokiyo

Shinya Saitoh

Hiroyuki Tanahashi

Shunsuke Tobayashi

A power converter including a diode converter, an inverter, a smoothing capacitor, a resistor; a current sensor; an estimation unit; and a control unit. The diode converter rectifies an alternating current from a power supply. The inverter is formed such that a DC side is connected to a DC output of the diode converter and an AC side is connected to an electric motor and includes a semiconductor switching element which converts DC power on the DC side into AC power and a reverse connection diode which is connected in antiparallel with the semiconductor switching element. The smoothing capacitor is provided in the DC output of the diode converter. The resistor is connected in parallel with the smoothing capacitor. The current sensor detects a load current flowing between the inverter and the electric motor.

Power converter and electric motor braking method

This high strength hot-rolled steel sheet includes: in terms of percent by mass, C: 0.05 to 0.12%; Si: 0.8 to 1.2%; Mn: 1.6 to 2.2%; Al: 0.30 to 0.6%; P: 0.05% or less; S: 0.005% or less; and N: 0.01% or less, with the remainder being Fe and unavoidable impurities, wherein a microstructure includes specific ranges (in area %) of ferrite phases as well as martensite phases, and a maximum concentration of Al detected by a glow discharge emission spectroscopic analysis is in a range of 0.75 mass % or less in a region from a surface of the steel sheet to a thickness of 500 nm after being acid-pickled.

Method for producing a high strength hot-rolled steel plate exhibiting excellent acid pickling property, chemical conversion processability, fatigue property, stretch flangeability, and resistance to surface deterioration during molding, and having isotropic strength and ductility

High strength hot-rolled steel plate exhibiting excellent acid pickling property, chemical conversion processability, fatigue property, stretch flangeability, and resistance to surface deterioration during molding, and having isotropic strength and ductility

Growing community of inventors

Tokyo, Japan

Masashi Fukuda