Meidensha Corporation

Hiromi Sako

Shizunori Hamada

Kenji Kobori

Takeshi Kondo

Shota Urushibata

Isamu Hasegawa

Keiichi Kodachi

Takashi Kodama

Upon turn-off of IGBT, by suppressing variations in collector-emitter voltage between IGBTs connected in series, risk of breaking IGBT due to overvoltage breakdown can be reduced. In protection circuit provided for each of the plurality of IGBTsconnected in series, between collector and emitter of IGBT, avalanche elements D&#x2dc;D, resistance Rand avalanche element Dare sequentially connected in series. Capacitor Cand resistance Rare connected parallel between both ends of the avalanche element D, and capacitor Cand resistance Rare connected parallel between both ends of the avalanche element D. Between a common connection point of the resistance Rand the avalanche element Dand gate of the IGBT, resistance R, a parallel circuit of capacitor Cand resistance R, and a series component of Zener diodes ZDand ZDwhose polarities are opposite to each other, are connected in series.

Protection circuit for semiconductor switching element, and power conversion device

A multilevel power conversion device includes: N (N&#x2265;1) direct current voltage sources; a first flying capacitor; a second flying capacitor; and a phase module of a M phase (M&#x2265;2) being configured to output, from the output terminal, a potential of one of the input terminals, or a potential obtained by adding or subtracting the voltage of the capacitor to or from the potential of the one of the input terminals, by selectively controlling the respective switching elements in an ON/OFF manner.

Multilevel power conversion device with flying capacitor

Growing community of inventors

Numazu, Japan

Hiromi Sako