A power supply system capable of supplying an electric power to a load device, comprising: first and second power storage devices (6-1, 6-2) for allowing charging and discharging; a power line (MPL, MNL) for supplying and receiving an electric power between the power supply system and said load device; a first converter, arranged between said first power storage device and said power line (MPL, MNL), for performing voltage conversion between said first power storage device and said power line (MPL, MNL); a second converter, arranged between said second power storage device and said power line (MPL, MNL), for performing voltage conversion between said second power storage device and said power line (MPL, MNL); a control device for controlling said first and second converters (8-1, 8-2); and a first voltage sensor for sensing a voltage on said power line (MPL, MNL), characterized in that said first and second converters (8-1, 8-2) are separate DCDC converters, said control device is configured to perform temperature increase control for increasing temperature of at least one of said first and second power storage devices (6-1, 6-2) by supplying and receiving an electric power between said first and second power storage devices (6-1, 6-2) via said first and second converters (8-1, 8-2) and said power line (MPL, MNL), and during said temperature increase control, said control device is configured to control one of said first and second converters (8-1, 8-2) based on a result of an operation in voltage feedback control of said one converter using a deviation between a target voltage on said power line (MPL, MNL) and a voltage sensed by said first voltage sensor, and to control the other converter based on a result of an operation in voltage feedforward control of said other converter not using said deviation. first and second power storage devices (6-1, 6-2) for allowing charging and discharging; a power line (MPL, MNL) for supplying and receiving an electric power between the power supply system and said load device; a first converter, arranged between said first power storage device and said power line (MPL, MNL), for performing voltage conversion between said first power storage device and said power line (MPL, MNL); a second converter, arranged between said second power storage device and said power line (MPL, MNL), for performing voltage conversion between said second power storage device and said power line (MPL, MNL); a control device for controlling said first and second converters (8-1, 8-2); and a first voltage sensor for sensing a voltage on said power line (MPL, MNL), characterized in that said first and second converters (8-1, 8-2) are separate DCDC converters, said control device is configured to perform temperature increase control for increasing temperature of at least one of said first and second power storage devices (6-1, 6-2) by supplying and receiving an electric power between said first and second power storage devices (6-1, 6-2) via said first and second converters (8-1, 8-2) and said power line (MPL, MNL), and during said temperature increase control, said control device is configured to control one of said first and second converters (8-1, 8-2) based on a result of an operation in voltage feedback control of said one converter using a deviation between a target voltage on said power line (MPL, MNL) and a voltage sensed by said first voltage sensor, and to control the other converter based on a result of an operation in voltage feedforward control of said other converter not using said deviation.