Patent ID: 8183804

Claim:
An AC motor driving circuit for driving an AC motor from an AC power supply and a DC power supply, which is configured to feed and absorb electric power, the AC motor driving circuit comprising: a matrix converter configured to perform power conversion between the AC power supply and the AC motor, the matrix converter being connected between an output of the AC power supply and an input of the AC motor; a power conversion circuit configured to perform power conversion between the DC power supply and the AC motor, the power conversion circuit including a plurality of series connection circuits in each of which a unidirectional switch is connected back-to-back with a diode, and a first bidirectional switch is connected in series with the unidirectional switch, a junction between each unidirectional switch and the respective first bidirectional switch being connected to an input phase of the AC motor, a terminal of each unidirectional switch not connected to the respective first bidirectional switch being connected to a first terminal of the DC power supply, and a terminal of each first bidirectional switch not connected to the respective unidirectional switch being connected to a second terminal of the DC power supply.