Patent ID: 7423391

Claim:
A power conversion device comprising: a matrix converter connected to m direct current power supplies and an n-phase alternating current machine, m and n each representing a natural number of at least two; and a control device controlling an operation of said matrix converter, wherein said matrix converter includes a power conversion portion operative in response to a control signal received from said control device to convert power between said m direct current power supplies and said n-phase alternating current machine, and a connection portion operative in response to a control signal received from said control device to series connect i ones of said m direct current power supplies, i representing a natural number of at least two and at most m, and said power conversion portion receives one of direct current power output from each of said m direct current power supplies and that output from said i direct current power supplies series connected by said connection portion to convert said direct current power to alternating current power and output said alternating current power to said n-phase alternating current machine, or receives alternating current power from said n-phase alternating current machine to convert said alternating current power to direct current power and output said direct current power to any of said m direct current power supplies.