Patent ID: 7278037

Claim:
A storage system, comprising: a channel adapter coupled to a host computer and receiving a read/write command sent from the host computer; a memory coupled to the channel adapter and storing data transferred from the channel adapter; a disk adapter coupled to the memory and transferring data stored in the memory to a plurality of storage regions; a plurality of disk drive units having the storage regions and storing data transferred from the disk adapter; at least one Direct Current (DC) power supply device supplying DC power to at least one load and having plural phases of Alternate Current Direct Current (AC-DC) converters and a current balancing circuit; and at least one Alternate Current (AC) unit having at least one breaker, which breaker interrupts supply of AC power if AC power exceeds a certain level, and receiving AC power supplied from outside and supplying AC power to the DC power supply device, wherein the load includes the channel adapter, the memory, the disk adapter or the disk drive units, and wherein the current balancing circuit balances DC power supplied from the plural phases of AC-DC converters.