| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent an inverter switching element of an indirect matrix converter from being damaged by a surge voltage. <P>SOLUTION: The indirect matrix converter connects a converter 2 to an inverter 6 via a bus 4p of positive polarity and a bus 4n of negative polarity. An anode of a clamp diode 28u is connected to the bus 4p of positive polarity, a cathode is connected to one end of a capacitor 30, the other end of the capacitor 30 is connected to an anode of a clamp diode 28d, and a cathode is connected to the bus 4n of negative polarity. Switch elements 16uu to 16uw of the inverter 6 are provided with a snapper circuit 20u of upper discharge blocking type and switch elements 16du to 16dw of the inverter 6 are provided with a snapper circuit 20d of lower discharge blocking type. A discharge resistor 26u of the snapper circuit 20u of upper discharge blocking type is connected to the anode of the diode 28d and a discharge resistor 26d of the snapper circuit 20d of lower discharge blocking type is connected to an anode of a diode 26u. <P>COPYRIGHT: (C)2012,JPO&INPIT |
