Solar power generation system

1. A solar power generation system of a vehicle, the solar power generation system comprising:

a solar panel configured to generate power by sunlight;

a first load;

an auxiliary battery configured to supply power to the first load;

a second load configured to drive the vehicle;

a driving battery configured to supply power to drive the vehicle to the second load;

a first power converter configured to supply the power generated by the solar panel to the auxiliary battery;

a second power converter configured to bidirectionally exchange power between the auxiliary battery and the driving battery; and

a processor programmed to:

only in a vehicle off state and when a power storage amount of the auxiliary battery is equal to or greater than a first threshold, instruct the second power converter to supply power of the auxiliary battery to the driving battery until the power storage amount of the auxiliary battery decreases to a lower limit value lower than the first threshold; and

only in a vehicle on state:

when the power storage amount of the auxiliary battery is equal to or greater than a second threshold, instruct the second power converter to supply power of the auxiliary battery to the driving battery with constant power output; and

when the power storage amount of the auxiliary battery is less than the second threshold, instruct the second power converter to supply power of the driving battery to the auxiliary battery with constant voltage output.

2. The solar power generation system according to claim 1 , wherein the processor is programmed to, in a vehicle on state, instruct the second power converter to supply power of the driving battery to the auxiliary battery when the power storage amount of the auxiliary battery is equal to or less than an upper limit value, and supply power of the auxiliary battery to the driving battery when the power storage amount of the auxiliary battery exceeds the upper limit value.

3. The solar power generation system according to claim 1 , wherein the auxiliary battery is a lithium cell.

4. A method of controlling a solar power generation system of a vehicle, the solar power generation system comprising: a solar panel configured to generate power by sunlight; a first load; an auxiliary battery configured to supply power to the first load; a second load configured to drive the vehicle; a driving battery configured to supply power to drive the vehicle to the second load; a first power converter configured to supply the power generated by the solar panel to the auxiliary battery; a second power converter configured to bidirectionally exchange power between the auxiliary battery and the driving battery; and a processor, the method comprising performing the following steps using the processor:

only in a vehicle off state:

determining whether a power storage amount of the auxiliary battery exceeds a first threshold;

instructing the second power converter to supply power of the auxiliary battery to the driving battery when the power storage amount of the auxiliary battery exceeds the first threshold;

determining whether the power storage amount of the auxiliary battery decreases to a lower limit value lower than the first threshold; and

instructing the second power converter to stop supply of power of the auxiliary battery to the driving battery when the power storage amount of the auxiliary battery decreases to the lower limit value; and

only in a vehicle on state:

comparing the power storage amount of the auxiliary battery to a second threshold;

when the power storage amount of the auxiliary battery is equal to or greater than the second threshold, instructing the second power converter to supply power of the auxiliary battery to the driving battery with constant power output; and

when the power storage amount of the auxiliary battery is less than the second threshold, instructing the second power converter to supply power of the driving battery to the auxiliary battery with constant voltage output.

5. A non-transitory computer readable medium that embodies instructions that cause a processor to perform a method of controlling a solar power generation system of a vehicle, the solar power generation system comprising: a solar panel configured to generate power by sunlight; a first load; an auxiliary battery configured to supply power to the first load; a second load configured to drive the vehicle; a driving battery configured to supply power to drive the vehicle to the second load; a first power converter configured to supply the power generated by the solar panel to the auxiliary battery; a second power converter configured to bidirectionally exchange power between the auxiliary battery and the driving battery; and the processor, the method comprising performing the following steps using the processor:

only in a vehicle off state:

determining whether a power storage amount of the auxiliary battery exceeds a first threshold;

instructing the second power converter to supply power of the auxiliary battery to the driving battery when the power storage amount of the auxiliary battery exceeds the first threshold;

determining whether the power storage amount of the auxiliary battery decreases to a lower limit value lower than the first threshold; and

instructing the second power converter to stop supply of power of the auxiliary battery to the driving battery when the power storage amount of the auxiliary battery decreases to the lower limit value; and

only in a vehicle on state:

comparing the power storage amount of the auxiliary battery to a second threshold;

when the power storage amount of the auxiliary battery is equal to or greater than the second threshold, instructing the second power converter to supply power of the auxiliary battery to the driving battery with constant power output; and

when the power storage amount of the auxiliary battery is less than the second threshold, instructing the second power converter to supply power of the driving battery to the auxiliary battery with constant voltage output.