POWER SUPPLY DEVICE AND CHARGE-DISCHARGE CONTROL METHOD

• US 20110127943A1
• Filed: 08/24/2010
• Published: 06/02/2011
• Est. Priority Date: 11/30/2009
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Oto, Katsuya
• Granted Patent: US 8,410,749 B2
• Time in Patent Office: Days
• US Class Current: 320/101
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 10/46 Accumulators structurally combined with charging apparatus circuits for charging H02J7/00
• CPC Class Codes: H01M 16/006 of fuel cells with rechargeable batteries
• CPC Class Codes: H02J 2207/40 adapted for charging from various sources, e.g. AC, DC or multivoltage
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

According to one embodiment, a power supply device includes a fuel cell, a battery, a switch, and a controller. The fuel cell supplies electric power to an electronic device provided with a built-in battery. The battery is charged with electric power supplied from the fuel cell and supplies electric power to the electronic device. The switch switches the battery between charge mode and discharge mode. The controller controls the switch to switch the battery between the charge mode and the discharge mode. The controller calculates integrated discharge electric power and integrated discharge amount of the battery and, when the integrated discharge electric power reaches predetermined discharge electric power, switches the battery from the discharge mode to the charge mode. The controller calculates integrated charge amount of the battery and, when the integrated charge amount reaches the integrated discharge amount, switches the battery from the charge mode to the discharge mode.

Claims

1. A power supply device comprising:

a fuel cell configured to supply electric power to an electronic device provided with a built-in battery;

a battery configured to be charged with electric power supplied from the fuel cell and supply electric power to the electronic device;

a switch configured to switch the battery between charge mode and discharge mode; and

a controller configured to control the switch to switch the battery between the charge mode and the discharge mode, wherein

the controller is configured to calculate integrated discharge electric power and integrated discharge amount of the battery while the battery is being discharged and, when the integrated discharge electric power reaches predetermined discharge electric power, switch the battery from the discharge mode to the charge mode, and

the controller is configured to calculate integrated charge amount of the battery while the battery is being charged and, when the integrated charge amount reaches the integrated discharge amount, switch the battery from the charge mode to the discharge mode.

2. The power supply device of claim 1, wherein the predetermined discharge electric power corresponds to a predetermined percentage of electric power dischargeable from the battery that is fully charged.

3. The power supply device of claim 1, wherein, when voltage of the battery reaches upper-limit charge voltage lower than full charge voltage of the battery, the controller controls the switch to switch the battery from the charge mode to the discharge mode in preference to controlling the switch based on the integrated discharge amount.

4. The power supply device of claim 1, wherein, when voltage of the battery reaches lower-limit discharge voltage higher than discharge end voltage of the battery, the controller controls the switch to switch the battery from the discharge mode to the charge mode in preference to controlling the switch based on the integrated discharge electric power.

5. The power supply device of claim 4, wherein, when the voltage of the battery reaches the lower-limit discharge voltage and the battery is switched to the charge mode before discharging the predetermined discharge electric power, the controller charges the battery to a predetermined percentage of capacity of the battery.

6. The power supply device of claim 1, wherein the controller is configured to monitor output voltage of the battery while the battery is being charged and control charge current of the battery such that output voltage of the fuel cell is higher than voltage of the battery.

7. The power supply device of claim 1, further comprising an input terminal through which electric power is supplied from an external power source to the battery.

8. A charge-discharge control method applied to a power supply device comprising a fuel cell configured to supply electric power to an electronic device provided with a built-in battery, a battery configured to be charged with electric power supplied from the fuel cell and supply electric power to the electronic device, and a switch configured to switch the battery between charge mode and discharge mode, the charge-discharge control method comprising:

a controller calculating integrated discharge electric power and integrated discharge amount of the battery while the battery is being discharged and, when the integrated discharge electric power reaches predetermined discharge electric power, controlling the switch to switch the battery from the discharge mode to the charge mode; and

the controller calculating integrated charge amount of the battery while the battery is being charged and, when the integrated charge amount reaches the integrated discharge amount, controlling the switch to switch the battery from the charge mode to the discharge mode.

9. The charge-discharge control method of claim 8, wherein, when voltage of the battery reaches upper-limit charge voltage lower than full charge voltage of the battery, the controller controls the switch to switch the battery from the charge mode to the discharge mode in preference to controlling the switch based on the integrated discharge amount.

10. The charge-discharge control method of claim 8, wherein, when voltage of the battery reaches lower-limit discharge voltage higher than discharge end voltage of the battery, the controller controls the switch to switch the battery from the discharge mode to the charge mode in preference to controlling the switch based on the integrated discharge electric power.