Patent ID: 7750505

Claim:
A power supply system having a plurality of power storage units each configured to be chargeable/dischargeable, comprising: a power line configured to allow supply/reception of electric power between a load device and said power supply system; a plurality of voltage conversion units provided between said plurality of power storage units and said power line, respectively, and each performing voltage conversion operation between corresponding said power storage unit and said power line; power storage voltage value obtaining means obtaining a power storage voltage value for each of said plurality of power storage units; and voltage reference value determination means determining a voltage reference value of electric power to be supplied to said load device in accordance with torque and rotation speed values of said load device, each of said plurality of voltage conversion units performing said voltage conversion operation in accordance with said voltage reference value determined by said voltage reference value determination means so that a voltage supplied to the load device is substantially equal to the voltage reference value, said voltage reference value determination means limiting said voltage reference value not to fall below the maximum power storage voltage value of said power storage voltage values obtained by said power storage voltage value obtaining means.