SYSTEMS AND METHODS FOR CHARGING SUPER CAPACITORS

• US 20080303488A1
• Filed: 05/19/2008
• Published: 12/11/2008
• Est. Priority Date: 06/11/2007
• Status: Active Grant

• Current Assignee: Itron, Inc.
• Original Assignee: SmartSynch Incorporated (Itron, Inc.)
• Inventors: KHAN, Zafarullah
• Granted Patent: US 8,049,470 B2
• Time in Patent Office: Days
• US Class Current: 320/167
• CPC Class Codes: H01G 11/08 Structural combinations, e.g. assembly or connection, of hybrid or EDL capacitors with other electric components, at least one hybrid or EDL capacitor being the main component
• CPC Class Codes: H01G 11/10 Multiple hybrid or EDL capacitors, e.g. arrays or modules housings, cases, encapsulations or mountings thereof H01G11/78
• CPC Class Codes: H01G 11/14 Arrangements or processes for adjusting or protecting hybrid or EDL capacitors emergency protective circuit arrangements specially adapted for capacitors, and effecting automatic switching in the event of an undesired change from normal working conditions H02H7/16; emergency protective circuit arrangements for limiting excess current or voltages without disconnection H02H9/00
• CPC Class Codes: H02J 7/0071 with a programmable schedule
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: H02J 7/007188 the charge cycle being controlled or terminated in response to non-electric parameters
• CPC Class Codes: H02J 7/007192 in response to temperature
• CPC Class Codes: H02J 7/007194 of the battery
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors

Abstract

Systems and methods are provided for charging a super capacitor bank. One method provides for determining a charge voltage for the super capacitor bank, providing a charging current, limiting the charging current according to a corresponding worst case temperature within the super capacitor bank operating temperature range, limiting the charge voltage according to the worst case temperature, and turning off the charging current once the super capacitor bank is charged. One system provides a super capacitor bank for storing energy providing specified power demand to a circuit, a current charger providing charging current to the super capacitor bank, the charging current limited in accordance with a corresponding worst case temperature within the super capacitor bank operating temperature range, a voltage sense circuit to detect the super capacitor bank voltage, and a control to disconnect the current charger from the super capacitor bank once the super capacitor bank is charged.

Claims

1. A method for charging a super capacitor bank, the method comprising:

determining a desired charge voltage for the super capacitor bank;

providing a charging current to the super capacitor bank;

limiting the charging current according to a corresponding worst case temperature within the super capacitor bank operating temperature range;

limiting the charge voltage according to the worst case temperature within the super capacitor bank operating temperature range; and

turning off the charging current upon a determination that the super capacitor bank has been charged to the desired charge voltage.

2. The method of claim 1, further comprising turning on the charging current upon a determination that the super capacitor bank charge voltage has dropped a specified percentage below the desired charge voltage.

3. The method of claim 1, further comprising:

maintaining the charging current below a specified maximum charging current for the super capacitor bank; and

limiting a charge time below a corresponding maximum allowable charge time for the super capacitor bank.

4. The method of claim 1, further comprising maintaining the charging current at a constant value.

5. The method of claim 1, wherein energy capacity and voltage rating of the super capacitor bank are configured to store energy sufficient for a specified application.

6. A method for charging a super capacitor bank, the method comprising:

determining a charging current limit for the super capacitor bank, wherein the charging current limit is the maximum charging current for the super capacitor bank at worst case temperature within the super capacitor bank operating temperature range;

determining a charging voltage limit for the super capacitor bank, wherein the charging voltage limit is the maximum voltage for the super capacitor bank at worst case temperature within the super capacitor bank operating temperature range;

providing a charging current to the super capacitor bank, wherein the charging current is less than the charging current limit;

maintaining the charging voltage below the charging voltage limit; and

turning off the charging current upon determining that the super capacitor bank has charged to a specified charge voltage.

7. The method of claim 6, further comprising turning on the charging current upon a determination that the super capacitor bank charge voltage has dropped a specified percentage below the specified charge voltage.

8. The method of claim 6, further comprising limiting a charge time for the charging current, wherein the limited charge time is below a corresponding maximum allowable charge time for the super capacitor bank.

9. The method of claim 6, further comprising maintaining the charging current at a constant value.

10. The method of claim 6, wherein energy capacity and voltage rating of the super capacitor bank are configured to store energy sufficient for a specified application.

11. A method for charging a super capacitor bank, the method comprising:

providing a regulated voltage, wherein the regulated voltage is the maximum voltage for the super capacitor bank at worst case temperature within the super capacitor bank operating temperature range;

providing a charging current to the super capacitor bank; and

limiting the charging current below a specified maximum charging current, wherein the maximum charging current is specified for the super capacitor bank according to worst case temperature within the super capacitor bank operating temperature range.

12. The method of claim 11, further comprising limiting a charge time for the charging current, wherein the limited charge time is below a corresponding maximum allowable charge time for the super capacitor bank.

13. The method of claim 11, further comprising maintaining the charging current at a constant value.

14. The method of claim 11, wherein energy capacity and voltage rating of the super capacitor bank are configured to store energy sufficient for a specified application.

15. A method for charging a super capacitor bank, the method comprising:

determining a charging current limit for the super capacitor bank, wherein the charging current limit is the maximum charging current for the super capacitor bank at worst case temperature within the super capacitor bank operating temperature range;

providing a regulated voltage, wherein the regulated voltage is the maximum voltage for the super capacitor bank at worst case temperature within the super capacitor bank operating temperature range; and

providing a charging current to the super capacitor bank, wherein the charging current is less than the charging current limit.

16. The method of claim 15, further comprising limiting a charge time for the charging current, wherein the charge time is below a corresponding maximum allowable charge time for the super capacitor bank.

17. The method of claim 15, further comprising maintaining the charging current at a constant value.

18. The method of claim 15, wherein energy capacity and voltage rating of the super capacitor bank are configured to store energy sufficient for a specified application.

19. A system for charging a super capacitor bank, the system comprising:

a super capacitor bank configured for storing energy, the super capacitor bank further configured to provide a specified power demand to a circuit;

a current charger configured to provide a charging current to the super capacitor bank, the charging current limited to a maximum charging current corresponding to a worst case temperature within the super capacitor bank operating temperature range;

a voltage sense circuit configured for detecting the voltage of the super capacitor bank; and

a control configured to disconnect the current charger from the super capacitor bank upon the voltage sense circuit detecting a specified voltage at the super capacitor bank.

20. The system of claim 19, wherein the control is further configured to connect the current charger to the super capacitor bank upon the voltage sense circuit detecting that the voltage at the super capacitor bank has dropped a specified percentage below the specified voltage.

21. The system of claim 19, further comprising a charge time limiter configured for limiting maximum allowable charge time for the super capacitor bank to a specified value.

22. The system of claim 19, wherein the current charger is further configured to maintain the charging current at a constant value.

23. The system of claim 19, wherein energy capacity and voltage rating of the super capacitor bank are configured to store energy sufficient for a specified application.