Power supply apparatus, vehicle and control method

1. A power supply apparatus for supplying power received from an external power supply to a load, the power supply apparatus comprising:

a plurality of power supply circuitries connected in parallel, each of which has switching elements, that are allowed to supply power to the load separately; and

a processor that, in operation, controls a number of the power supply circuitries supplying power to the load according to a required power level of the load,

wherein the processor determines the number of the power supply circuitries such that the number of the power supply circuitries supplying power to the load decreases as the required power level is set to be smaller,

wherein when the required power level of the load is equal to or lower than ⅓ of the maximum value of a total output power, the processor controls the power supply circuit so that the number of the power supply circuits supplying the power to the load is one,

wherein when the required power level of the load is higher than ⅓ of the maximum value of the total output power and is lower than ⅔ of the total output power, the processor controls the power supply circuit so that the number of the power supply circuits supplying the power to the load is two, and

wherein when the required power level of the load is higher than ⅔ of the maximum value of the total output power, the processor controls the power supply circuit so that the number of the power supply circuits supplying the power to the load is three.

2. The power supply apparatus according to claim 1 , wherein

each of the plurality of power supply circuitries is allowed to operate separately, and

the processor, when neither of all the power supply circuitries is active, causes all the plurality of power supply circuitries to be inactive.

3. The power supply apparatus according to claim 1 , wherein the processor selects the power supply circuitry supplying power to the load according to durability condition of the plurality of power supply circuitries respectively.

4. The power supply apparatus according to claim 1 , wherein the load is a battery.

5. The power supply apparatus according to claim 4 , wherein the processor, when operating at least two power supply circuitries to charge the battery, decreases the at least two power supply circuitries according to remaining charge of the battery.

6. The power supply apparatus according to claim 1 , wherein when the required power level is larger than input power from the external power supply after the number of the power supply circuitries is determined according to the required power level, the processor decreases the number of the power supply circuitries according to the input power.

7. The power supply apparatus according to claim 1 , wherein each of the plurality of power supply circuitries is allowed to operate separately, and the processor, when neither of all the power supply circuitries is active, causes all the plurality of power supply circuitries to be inactive.

8. The power supply apparatus according to claim 1 , wherein the processor selects the power supply circuitry supplying power to the load according to durability condition of the plurality of power supply circuitries respectively.

9. The power supply apparatus according to claim 2 , wherein the processor selects the power supply circuitry supplying power to the load according to durability condition of the plurality of power supply circuitries respectively.

10. The power supply apparatus according to claim 1 , wherein the load is a battery.

11. The power supply apparatus according to claim 2 , wherein the load is a battery.

12. The power supply apparatus according to claim 3 , wherein the load is a battery.

13. The power supply apparatus according to claim 10 , wherein the processor, when operating at least two power supply circuitries to charge the battery, decreases the at least two power supply circuitries according to remaining charge of the battery.

14. The power supply apparatus according to claim 11 , wherein the processor, when operating at least two power supply circuitries to charge the battery, decreases the at least two power supply circuitries according to remaining charge of the battery.

15. The power supply apparatus according to claim 12 , wherein the processor, when operating at least two power supply circuitries to charge the battery, decreases the at least two power supply circuitries according to remaining charge of the battery.

16. The power supply apparatus according to claim 1 , wherein when the required power level is larger than input power from the external power supply after the number of the power supply circuitries is determined according to the required power level, the processor decreases the number of the power supply circuitries according to the input power.

17. The power supply apparatus according to claim 2 , wherein when the required power level is larger than input power from the external power supply after the number of the power supply circuitries is determined according to the required power level, the processor decreases the number of the power supply circuitries according to the input power.

18. A vehicle, comprising:

a load; and

a power supply apparatus that, in operation, supplies power received from an external power supply to the load, the power supply apparatus comprising:

a plurality of power supply circuitries connected in parallel, each of which has switching elements, that are allowed to supply power to the load separately; and

a processor that, in operation, controls a number of the power supply circuitries supplying power to the load according to a required power level of the load,

wherein the processor determines the number of the power supply circuitries such that the number of the power supply circuitries supplying power to the load decreases as the required power level is set to be smaller,

wherein when the required power level of the load is equal to or lower than ⅓ of the maximum value of a total output power, the processor controls the power supply circuit so that the number of the power supply circuits supplying the power to the load is one,

wherein when the required power level of the load is higher than ⅓ of the maximum value of the total output power and is lower than ⅔ of the total output power, the processor controls the power supply circuit so that the number of the power supply circuits supplying the power to the load is two, and

wherein when the required power level of the load is higher than ⅔ of the maximum value of the total output power, the processor controls the power supply circuit so that the number of the power supply circuits supplying the power to the load is three.

19. A control method of a power supply apparatus that includes a plurality of power supply circuitries, each of which has switching elements connected in parallel, and supplies power received from an external power supply to a load, the control method comprising:

determining a number of the power supply circuitries supplying power to the load according to a required power level of the load; and

controlling the plurality of the power supply circuitries separately based on the number of the power supply circuitries,

wherein the determining includes determining the number of the power supply circuitries such that the number of the power supply circuitries supplying power to the load decreases as the required power level is set to be smaller,

wherein when the required power level of the load is equal to or lower than ⅓ of the maximum value of a total output power, the controlling includes controlling the power supply circuit so that the number of the power supply circuits supplying the power to the load is one,

wherein when the required power level of the load is higher than ⅓ of the maximum value of the total output power and is lower than ⅔ of the total output power, the controlling includes controlling the power supply circuit so that the number of the power supply circuits supplying the power to the load is two, and

wherein when the required power level of the load is higher than ⅔ of the maximum value of the total output power, the controlling includes controlling the power supply circuit so that the number of the power supply circuits supplying the power to the load is three.