Power supply system

A power supply system comprising:

• a first power conversion circuit;
• and
• a second power conversion circuit, the first power conversion circuit and the second power conversion circuit being connected in parallel to a first power supply that is mounted on a vehicle and that outputs a voltage of a first level, wherein
• each of the first power conversion circuit and the second power conversion circuit is capable of converting a voltage of the first level into a voltage of a second level and a voltage of a third level, and converting a voltage of the second level into a voltage of the third level,
• the voltage of the second level and the voltage of the third level output from the first power conversion circuit are capable of being supplied to a first load of the vehicle,
• the voltage of the second level and the voltage of the third level output from the second power conversion circuit are capable of being supplied to a second load of the vehicle,
• the power supply system further comprises:
• a first switch configured to switch between connection and cutoff between a first power supply line connecting the first power conversion circuit and the first load and a second power supply line connecting the second power conversion circuit and the second load, the first power supply line and the second power supply line being power supply lines to be supplied with a voltage of the second level;
• a second switch configured to switch between connection and cutoff between a third power supply line connecting the first power conversion circuit and the first load and a fourth power supply line connecting the second power conversion circuit and the second load, the third power supply line and the fourth power supply line being power supply lines to be supplied with a voltage of the third level;
• and
• a second power supply connected to the first power supply line and configured to output a voltage of the second level,
• in a non-started-up state of the vehicle,
• the first power conversion circuit operates in a first mode in which the voltage of the second level supplied from the second power supply is converted into a voltage of the third level,
• the first switch and the second switch are each controlled to a connection state,
• the voltage of the second level output from the second power supply is supplied to the first load and the first power conversion circuit,
• the voltage of the second level output from the second power supply is supplied to the second load via the first switch,
• the voltage of the third level output from the first power conversion circuit is supplied to the first load, and
• the voltage of the third level output from the first power conversion circuit is supplied to the second load via the second switch.