Methods and apparatus for storing electrical energy

• US 20020140405A1
• Filed: 04/02/2002
• Published: 10/03/2002
• Est. Priority Date: 04/03/2001
• Status: Active Grant

• Current Assignee: Continental Isad Electronics Systems GmbH & Co. OhG (Continental AG)
• Original Assignee: Continental Isad Electronics Systems GmbH & Co. OhG (Continental AG)
• Inventors: Malik, Manfred
• Granted Patent: US 6,788,027 B2
• Time in Patent Office: Days
• US Class Current: 320/166
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2210/12 Buck converters
• CPC Class Codes: B60L 2210/14 Boost converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/662 Temperature
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/40 using propulsion power supplied by capacitors
• CPC Class Codes: B60L 58/18 of two or more battery modules
• CPC Class Codes: B60L 58/20 having different nominal voltages
• CPC Class Codes: B60L 58/25 by controlling the electric load
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2510/246 Temperature
• CPC Class Codes: F02N 11/04 the motors being associated with current generators
• CPC Class Codes: F02N 11/0866 comprising several power sources, e.g. battery and capacitor or two batteries
• CPC Class Codes: F02N 2011/0885 Capacitors, e.g. for additional power supply
• CPC Class Codes: F02N 2011/0888 DC/DC converters
• CPC Class Codes: F02N 2200/063 Battery voltage
• CPC Class Codes: F02N 2200/064 : Battery temperature
• CPC Class Codes: H01G 15/00 : Structural combinations of capacitors or other devices covered by at least two different main groups of this subclass with each other involving at least one hybrid or electric double-layer [EDL] capacitor as the main component H01G11/08
• CPC Class Codes: H02J 2207/20 : Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 2310/48 : for electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: H02J 7/007194 : of the battery
• CPC Class Codes: H02J 7/345 : using capacitors as storage or buffering devices
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y02T 90/16 : Information or communication technologies improving the operation of electric vehicles

Abstract

Systems and methods are disclosed to store electrical energy in, for example, a vehicle. In an example system, a storage module is provided including one or more capacitors, a sensor to measure the temperature of the capacitor(s), and a control device that controls the voltage at the capacitor(s) so that the maximum voltage at the storage module and/or the individual capacitor(s) increases as the temperature decreases. The aging of the capacitor(s) and in particular electrochemical capacitors strongly depends on the temperature in addition to the operating voltage. Controlling the capacitor voltage based on temperature can, therefore, substantially reduce the aging of the capacitor(s).

Claims

1. A system for storing electrical energy comprising:

a storage module including a capacitor;

a sensor to sense a temperature associated with the capacitor; and

a controller in communication with the sensor to control a voltage at the capacitor so that a maximum voltage associated with at least one of the storage module and the capacitor increases as the temperature sensed by the sensor decreases.

2. A system as defined in claim 1 wherein the capacitor comprises an electrochemical capacitor.

3. A system as defined in claim 1 wherein the capacitor comprises at least one of:

(1) a double-layer capacitor,

(2) a Faraday capacitor, and

(3) a mixed form of a double-layer capacitor and a chemical storage device.

4. A system as defined in claim 1 further comprising a power electronics module to set a charge voltage for the storage module, wherein the controller controls the voltage at the capacitor so that the maximum voltage at the at least one of the storage module and the capacitor increases as the temperature sensed by the sensor decreases by providing the power electronics module with a maximum charge voltage that increases as the temperature falls.

5. A system as defined in claim 1 further comprising a long-term storage device.

6. A system as defined in claim 5 further comprising a generator driven by an internal combustion engine to charge the storage module and the long-term storage device.

7. A system as defined in claim 6 wherein the generator is a three-phase machine, and a voltage generated by the generator is fed through a rectifier into a DC link.

8. A system as defined in claim 6 wherein the generator comprises a crankshaft starter generator.

9. A system as defined in claim 7 wherein at least one of the power electronics module and the long-term storage device is connected to the DC link.

10. A system as defined in claim 1 wherein the capacitor comprises a first capacitor, and the storage module includes a second capacitor connected in series with the first capacitor.

11. A system as defined in claim 10 further comprising a balancing circuit including a first load resistor and a first controlled switch in circuit with the first capacitor, and a second load resistor and a second controlled switch in circuit with the second capacitor, wherein the first capacitor has a first voltage and the second capacitor has a second voltage, and a difference between the first and second voltages is compensated by controlling at least one of the first and second switches to respectively connect at least one of the first and second load resistors to at least one of the first and second capacitors to at least partially discharge the at least one of the first and second capacitors, respectively.

12. A system as defined in claim 11 further comprising a temperature-sensitive switching element to switch the first controlled switch when a specific temperature is exceeded.

13. A system as defined in claim 12 wherein the temperature-sensitive switching element comprises an NTC resistor.

14. A system as defined in claim 11 wherein the first controlled switch is temperature sensitive and switches when a specfic temperature is exceeded.

15. A system as defined in claim 14 wherein the first controlled switch comprises a temperature-dependent diode.

16. A system as defined in claim 1 wherein at sensed temperatures below a threshold, the maximum voltage is above a predefined operating range of the capacitor.

19. A method as defined in claim 18 wherein the step of adjusting is performed each time energy is absorbed by or discharged from the storage module.

20. A method as defined in claim 18 wherein the level increases as the sensed temperature decreases.

21. A method as defined in claim 18 wherein, at temperatures below a threshold, the level is above a predefined operating range of the at least one capacitor.

22. A method as defined in claim 18 further comprising:

drawing energy from a long-term storage device;

charging the at least one capacitor with the drawn energy to a voltage that depends on the sensed temperature; and

thereafter supplying energy to an electrical starter from the at least one capacitor to start an internal combustion engine.

17. For use with an energy storage system comprising a storage module having at least one capacitor, a method comprising:

sensing a temperature associated with at least one of the storage module and the at least one capacitor; and

increasing a maximum voltage applied to at least one of the storage module and the at least one capacitor as the sensed temperature decreases.

18. For use with an energy storage system comprising a storage module having at least one capacitor, a method comprising:

sensing a temperature associated with at least one of the storage module and the at least one capacitor; and

adjusting an operating voltage associated with the storage module to a level which depends on (1) an intended life of the at least one capacitor and (2) the sensed temperature.