To dispense with optical signals in the transmission of control signals to the semiconductor devices in a power conversion device, in which each arm comprises a circuit formed by connecting a plurality of a semiconductor devices in series, and reduce the size and cost of the power conversion device and prevent destruction of the semiconductor devices.
The Figure illustrates a circuit which is equivalent to one arm in which three IGBT Q1 to Q3 are connected in series. The circuit is provided with level shifting circuits LS1 and LS2 that transmit switching control signals Vin from a controller SC from the lower potential side device Q1 to the higher potential side device Q3, in succession; and delay circuits TD1 and TD2 that delay the transmitted control signals by a fixed time. Thus, a plurality of the devices can be made identical with each other, in the timing of turn-on/off, and imbalance can be prevented from being produced between device voltages.
SASAGAWA KIYOAKI
Yoshihide Komada
Kiyoshi Matsuzaki
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