ELECTRIC POWER SOURCE SYSTEM FOR ELECTRICALLY DRIVEN VEHICLE AND ITS CONTROL METHOD

摘要

A power supply system includes a main power storage device (BA) and a plurality of sub power storage devices (BB1, BB2). A converter (12B) is connected to selected one of the sub power storage devices (BB1, BB2) to convert voltage between the selected sub power storage device and an electric power feeding line (PL2) bidirectionally. In the case of a switching-forced region where the SOC of the selected sub power storage device in use is lower than a lower limit reference value, the sub power storage device is forced to be switched regardless of the vehicle's state. In contrast, in the case of a switching-permitted region where the SOC is higher than that in the switching-forced region, a switch request is generated based on the vehicle's state under the condition that does not influence the vehicle's drivability.