ENGINE STORAGE DEVICE, PARTICULARLY FOR AN AUTOMOBILE

• US 20100090649A1
• Filed: 04/07/2008
• Published: 04/15/2010
• Est. Priority Date: 04/18/2007
• Status: Active Grant

• Current Assignee: Valeo Equipements Electriques Moteur (Valeo SE)
• Original Assignee: Valeo Equipements Electriques Moteur (Valeo SE)
• Inventors: Dessirier, Bruno, Sardat, Pierre, Doffin, Hugues, Matt, Jean-Claude
• Granted Patent: US 8,288,991 B2
• Time in Patent Office: Days
• US Class Current: 320/118
• CPC Class Codes: B60L 2260/46 by self learning
• CPC Class Codes: B60L 3/06 Limiting the traction current under mechanical overload conditions
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/22 Balancing the charge of battery modules
• CPC Class Codes: H01M 10/425 Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing printed circuits H05K1/00
• CPC Class Codes: H01M 10/441 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

The invention relates to an energy storage device, particularly for an automobile, that comprises: an assembly (2) of serially-connected energy storage cells; a balancing circuit adapted for balancing the cells during the discharge thereof by enabling the flow of one or more balancing currents in one or more cells of the assembly (2); optionally a diagnosis system (61) for providing at least one piece of information associated with at least one cell in the assembly; wherein the balancing circuit (10; 41) is adapted for controlling the balancing current(s) based at least on external information independent from the energy-storage cell assembly and/or information associated with at least one of the cells and provided by the optional diagnosis system.

Claims

1. An energy storage device, in particular for a motor vehicle, comprising:

an assembly (2) of energy storage cells (Ci) connected in series,

a balancing circuit connected between said storage cells configured to enable the cells (Ci) to be balanced while they are being discharged, by circulating at least one balancing current in at least one of said cells of the assembly (2),

a diagnostic system (61) configured to enable the delivery of at least one piece of information associated with at least one of the cells of the assembly,

the balancing circuit being configured to control at least one of the balancing current or the duration of balancing (Dr3) at least depending on an external piece of information independent of the assembly of energy storage cells or of said piece of information associated with at least one of the cells, delivered by the diagnostic system.

2. A device according to claim 1, characterised by the diagnostic system being configured to deliver information including temperature information associated with at least one of the cells, voltage information associated with one of the cells, voltage information associated with several cells of the assembly, voltage information at the terminals of the assembly itself.

3. A device according to claim 2, characterised by the balancing circuit being configured to allow the intensity of the balancing current to be varied from 0 Amperes to a maximum predetermined value.

4. A device according to claim 3, characterised by the balancing circuit (10;

41) being maintained in operation while the temperature associated with at least one of the cells is above a threshold equal to about 40°

C.

5. A device according claim 4, characterised by the diagnostic system (61) being configured to control at least one of the starting and the interruption of the balancing circuit.

6. A device according to claim 1, characterised by the external piece of information being selected from one of:

voltage information for a battery powering the vehicle'"'"'s onboard network, information issued by a battery management system (BMS), information for activation of the balancing circuit, wherein such information is issued by an engine control system and information linked to an onboard network power supply by detection of an ignition key in position +APC.

7. A device according to claim 6, characterised by the balancing circuit being configured so as to be able to function in two modes, a first mode in which the balancing of the energy storage cells is accompanied by one or more low balancing currents, especially when the vehicle is stationary, and a second mode in which the balancing of the cells is accompanied by one or more strong balancing currents, especially when the vehicle is moving.

8. A device according to claim 7, characterised by the balancing circuit switches from the first mode to the second mode once the voltage at the terminals of a battery of the vehicle or at the terminals of the assembly of cells exceeds a predetermined threshold, equal to 12 to 13 Volts.

9. A device according to claim 1, further comprising an oscillator (62) configured to control at least one of the starting and the interruption of the balancing circuit intermittently, via the diagnostic system (61).

10. A device according to claim 9, characterised by the oscillator (62) being configured to control the starting and the interruption of the diagnostic system (61).

11. A device according to claim 9, characterised by the fact that the oscillator directly controls the balancing circuit.

12. A device according to claim 9, characterised by the balancing circuit being configured to function for a predetermined period after being started by the oscillator (62), then, depending on the circumstances, to switch itself off after this predetermined period.

13. A device according to claim 1, characterised by the balancing circuit comprising one or more transformers of the flyback type.

14. A device according to claim 1, characterised by the balancing circuit being configured to allow an intensity of the balancing current or currents to be varied depending on the state of ageing of the cell or cells, the ageing being determined by at least one of the following pieces of information:

a value of the internal resistance of the energy storage cell or cells (ESR or Equivalent Series Resistance), a capacitance value of the energy storage cell or cells, the state of charge of one or more cells (SOC), the state of energy of one or more cells (SOE).

15. A device according to claim 1, the balancing being realised intermittently, characterised by the duration (Dr3) of at least one of a balancing phase and the duration (Dr4) between two successive triggerings of the balancing are linked to the state of ageing of the cell or of the cells Ci, the ageing being determined by at least one of the following pieces of information:

a value of the internal resistance of the energy storage cell or cells (ESR or Equivalent Series Resistance), a capacitance value of the energy storage cell or cells, the state of charge of one or more cells (SOC), the state of energy of one or more cells (SOE).

16. A device according to claim 1, the balancing being realised intermittently, characterised by the duration (Dr2) between two signals for the reactivation of balancing is selected depending on the state of ageing of the cell or of the cells, the ageing being determined by at least one of the following pieces of information:

a value of the internal resistance of the energy storage cell or cells (ESR or Equivalent Series Resistance), a capacitance value of the energy storage cell or cells, the state of charge of one or more cells (SOC), the state of energy of one or more cells (SOE).

17. A device according to claim 1, characterised by the diagnostic system being configured to deliver end-of-life information for the energy storage cell or cells, said information being in particular in the form of a warning signal, as a function of at least one of the frequency of activation of the balancing circuit and the intensity of the balancing current or currents.

18. An energy storage device, in particular for a motor vehicle, comprising:

an assembly (2) of energy storage cells (Ci) connected in series,

a balancing circuit connected to said cells configured to enable balancing of the cells (Ci) while they are being discharged, and, further including

an oscillator (62) configured to enable at least one of an intermittent triggering and a stoppage of the balancing circuit.

19. A method for balancing during a discharge, when the motor vehicle is stationary or running, of an energy storage device associated with said motor vehicle comprising an assembly (2) of energy storage cells connected in series, the method comprising the following steps:

enabling a balancing of the cells (Ci) while they are being discharged, by circulating one or more balancing currents in one or more cells of the assembly (2),

controlling the balancing current or currents, in particular to provoke the triggering of the balancing, at least depending on an external piece of information independent of the assembly of energy storage cells and/or information associated with at least one of the cells.

20. A method according to claim 19, characterised by the optimisation of the ratios (Dr1/Dr2), where Dr1 is a duration of a balancing activation signal and Dr2 is a duration between two signals for reactivation of a balancing phase, and (Dr3/Dr4), where Dr3 is a duration of the balancing phase and Dr4 is a duration between successive triggerings of a balancing phase, and of the intensity (Ip) is selected so as, firstly, to minimise the auto-discharge of the assembly of cells (Ci) in order to optimise the rate of availability of the assembly of cells (Ci) depending on the service profile and its state of ageing, and secondly, to have an image of the state of health of the assembly of cells (Ci) which can be utilised in a strategy for predicting the end of life of the assembly of cells (Ci).

21. An energy storage device (1′

), in particular for a motor vehicle, comprising;

an assembly (2) of energy storage cells (Ci) connected in series,

a balancing circuit (10′

) connected to said cells configured to enable, in a first phase (Ph 1), a discharge and a balancing of the cells (Ci) up to at least a low predetermined threshold (Einf) of voltage at the terminals of the energy storage cells and, in a second phase (Ph2) which follows the first phase, an accelerated discharge of the cells below said low predetermined threshold.

22. A device according to claim 21, characterised by the balancing circuit being configured so that at the end of the second phase (Ph2), the voltage at the terminals of each of the cells (Ci) is essentially zero.

23. A device according to claim 22, characterised by the balancing circuit (10′

) is configured so that the duration of the first phase (Ph1) is greater than that of the second phase (Ph2), in particular at least 10 times to at least 100 times greater.

24. A device according to claim 23, characterised by the balancing circuit (10′

) ceasing the forced balancing of the cells at the end of the first phase.

25. An energy storage device (1), in particular for a motor vehicle, comprising:

an assembly (2) of energy storage cells (Ci) connected in series, and

a balancing circuit (10;

41) connected to said cells configured to enable the drawing of energy from at least one of said cells and the distribution of the energy is thus drawn to at least one other of said cells.

26. A device according to claim 25, characterised by the balancing circuit (10) being configured to allow, during one phase of discharge of the energy storage device, the charging voltage of at least one of the cells to be increased only with the energy drawn from at least one of the energy storage cells of the device.

27. A device according to claim 26, characterised by the balancing circuit (10) being configured to enable symmetrical discharge of the cells (Ci) to a voltage at least 3 times weaker than the maximum serviceable voltage of the cells, in particular at least 10 times weaker to at least 20 times weaker.

28. A device according to claim 27, characterised by the balancing circuit (10) is configured so that it can be permanently connected to a power supply network of a motor vehicle.