Power supply system, vehicle including the same, control method for power supply system, and computer-readable recording medium recording program for causing computer to execute the control method
View Patent ↗A lower limit value setting unit ( 52 ) variably sets a lower limit value (Vth) of a target voltage (Vh*) in a range of a voltage that is higher than the maximum value of voltages (Vb 1 , Vb 2 ) of power storage devices and is not affected by a dead time provided for converters, based on temperatures (Tb 1 , Tb 2 ) and required electric powers (Pb 1 *, Pb 2 *). A maximum value selection unit ( 53 ) sets the maximum value among the voltages (Vb 1 , Vb 2 ) of the power storage devices and required voltages (Vm 1 *, Vm 2 *) of motor-generators, as the target voltage. A target voltage limiting unit ( 54 ) compares the target voltage with the lower limit value (Vth), and if the target voltage is lower than the lower limit value (Vth), the target voltage limiting unit ( 54 ) sets the lower limit value (Vth) as the target voltage (Vh*).
1. A power supply system capable of supplying/receiving electric power to/from a load device, comprising:
a power line for supplying/receiving the electric power between the power supply system and said load device;
a plurality of power storage devices that are chargeable/dischargeable;
a plurality of converters corresponding to said plurality of power storage devices, and each configured to be capable of performing voltage conversion between the corresponding power storage device and said power line;
a target voltage setting unit for setting a target voltage of said power line; and
a voltage control unit for controlling a voltage of said power line to be said target voltage by controlling at least one of said plurality of converters, wherein:
when said target voltage is lower than a target voltage lower limit value that is set higher than a maximum one of voltages of said plurality of power storage devices, said target voltage setting unit setting said target voltage lower limit value as said target voltage, and
said target voltage lower limit value is set to a voltage that is not affected by a dead time to prevent a short circuit in upper and lower arms of said plurality of converters.
2. The power supply system according to claim 1 , wherein said target voltage setting unit sets a maximum one of the voltages of said plurality of power storage devices and a required voltage of said load device as said target voltage, and, when the set target voltage is lower than said target voltage lower limit value, said target voltage setting unit sets said target voltage lower limit value as said target voltage.
3. The power supply system according to claim 1 , wherein said target voltage lower limit value is variably set in accordance with states of said plurality of power storage devices.
4. The power supply system according to claim 3 , wherein said target voltage lower limit value is set to be higher with a decrease in temperatures of said plurality of power storage devices.
5. The power supply system according to claim 3 , wherein said target voltage lower limit value is set to be higher with an increase in charge power to said plurality of power storage devices.
6. The power supply system according to claim 3 , wherein said target voltage lower limit value is set to be higher with an increase in charge current to said plurality of power storage devices.
7. The power supply system according to claim 3 , wherein said target voltage lower limit value is set to be higher with an increase in state quantity indicating a state of charge of said plurality of power storage devices.
8. A vehicle, comprising:
the power supply system according to claim 1 ; and
a drive force generation unit for receiving the electric power supplied from said power supply system and generating drive force for the vehicle.
9. A control method for a power supply system capable of supplying/receiving electric power to/from a load device, said power supply system including:
a power line for supplying/receiving the electric power between said power supply system and said load device;
a plurality of power storage devices that are chargeable/dischargeable; and
a plurality of converters corresponding to said plurality of power storage devices, and each configured to be capable of performing voltage conversion between the corresponding power storage device and said power line;
said control method comprising the steps of:
setting a target voltage of said power line;
determining whether or not said target voltage is lower than a target voltage lower limit value that is set higher than a maximum one of voltages of said plurality of power storage devices;
setting said target voltage lower limit value as said target voltage when said target voltage is determined to be lower than said target voltage lower limit value; and
controlling a voltage of said power line to be said target voltage by controlling at least one of said plurality of converters,
wherein said target voltage lower limit value is set to a voltage that is not affected by a dead time to prevent a short circuit in upper and lower arms of said plurality of converters.
10. The control method for a power supply system according to claim 9 , wherein, in said step of setting a target voltage, a maximum one of the voltages of said plurality of power storage devices and a required voltage of said load device is set as said target voltage.
11. The control method for a power supply system according to claim 9 , wherein said target voltage lower limit value is variably set in accordance with states of said plurality of power storage devices.
12. The control method for a power supply system according to claim 11 , wherein said target voltage lower limit value is set to be higher with a decrease in temperatures of said plurality of power storage devices.
13. The control method for a power supply system according to claim 11 , wherein said target voltage lower limit value is set to be higher with an increase in charge power to said plurality of power storage devices.
14. The control method for a power supply system according to claim 11 , wherein said target voltage lower limit value is set to be higher with an increase in charge current to said plurality of power storage devices.
15. The control method for a power supply system according to claim 11 , wherein said target voltage lower limit value is set to be higher with an increase in state quantity indicating a state of charge of said plurality of power storage devices.
16. A computer-readable recording medium recording a program for causing a computer to execute the control method for a power supply system according to claim 9 .
17. The power supply system according to claim 1 , further comprising a current control unit for controlling a current of one of said plurality of converters to be a target current by controlling one of said plurality of converters.