Charge equalization system for batteries

• US 9,085,243 B2
• Filed: 02/04/2011
• Issued: 07/21/2015
• Est. Priority Date: 02/05/2010
• Status: Expired due to Fees

• Current Assignee: Commissariat a L'Energie Atomique (French Alternative Energies and Atomic Energy Commission)
• Original Assignee: Commissariat a L'Energie Atomique (French Alternative Energies and Atomic Energy Commission)
• Inventors: Chatroux, Daniel, Dauchy, Julien, Fernandez, Eric, Mercier, Sylvain
• Primary Examiner(s): Tso, Edward
• Assistant Examiner(s): Boateng, Alexis A
• Application Number:
  US13/577,186
• Publication Number:
  US 20130038290A1
• Time in Patent Office: 1,628 Days
• Field of Search: 320/118, 320/119, 320/116, 320/117, 320/122, 320/109, 320/121, 320/162, 320/152, 320/103
• US Class Current: 1/1
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 58/14 Preventing excessive discharging
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: B60L 58/22 Balancing the charge of battery modules
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/486 for measuring temperature
• CPC Class Codes: H02J 2310/48 for electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: H02J 7/0018 using separate charge circuits
• CPC Class Codes: H02J 7/0019 using switched or multiplexed charge 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

An equalization system for batteries has two series-connected accumulator stages connected, each including an accumulator, a voltage generator including positive and negative poles, for each stage, an associated charging device supplied by the voltage generator. The charging device includes an inductor having a first and second ends, and a capacitor having first and second ends. The capacitor'"'"'s first end connects to the generator'"'"'s positive pole. It also has a diode whose anode connects to a negative pole of the accumulator stage and whose cathode connects to the inductor'"'"'s first end. It also has a switch whose first end connects to the inductor. And it also has a control device that controls the generator and closes a switch of a charging device associated with an accumulator stage to be charged so that the inductor stores energy, and causes its transfer to that accumulator stage.

Claims

1. An apparatus comprising a battery equalization system, said battery equalization system comprising two stages of accumulators placed in series, each stage having a negative pole and a positive pole, each stage comprising an accumulator placed between said negative pole and said positive pole, a voltage generator comprising a positive terminal and a negative terminal, for each stage of accumulators, an associated charging device powered by said voltage generator, said associated charging device comprising an inductor, a first capacitor having a first end and a second end, said first end being connected to a terminal of said voltage generator, a diode having an anode and a cathode, said diode being connected by said anode to said negative pole of said associated stage of accumulators and connected to an end of said inductor to allow, when said diode is forward biased, a flow of a charging current through said associated stage of accumulators, said associated diode and said associated inductor, and a switch, one end of which is linked to an end of said inductor so that said switch, said inductor and said first capacitor of said associated charging device are connected in series between a terminal of said voltage generator and a pole of said associated stage of accumulators, and a control device configured to, during a conduction time interval, to apply a voltage variation between said terminals of said voltage generator and to close a switch of a charging device associated with a stage of accumulators to be charged such that said inductor and said switch of said charging device are traversed by an increasing power supply current originating from said voltage generator and such that said inductor stores energy, and after said conduction time interval, to interrupt said power supply current through said inductor and allow transfer of the energy stored in said inductor to said associated stage of accumulators by flow of a decreasing charging current through said associated inductor and said associated diode.

2. The apparatus of claim 1, wherein said voltage generator is connected to a predefined number of charging devices.

3. The apparatus of claim 1, wherein said first capacitor comprises a first end connected to said positive terminal of said voltage generator.

4. The apparatus of claim 3, wherein a second end of said first capacitor is connected to a first end of said inductor, a cathode of said diode is connected to the second end of the first capacitor, and the switch of the charging device is connected by a first end to a second end of the inductor and by a second end to the positive pole of the associated stage of accumulators.

5. The apparatus of claim 3, wherein said charging device includes a first capacitor, a first side of which is connected to said positive terminal of said voltage generator and a second side of which is connected to a first end of said inductor, a second capacitor, a first side of which is connected to said negative terminal of said voltage generator and a second side of which is connected to said negative pole of said associated stage of accumulators or to a second end of said inductor and to said positive pole of said associated stage of accumulators, and wherein said diode is connected, by said anode thereof, to said negative pole of said associated stage of accumulators, and wherein said diode is connected, by said cathode thereof, to said first end of said inductor, and wherein said switch of said charging device is connected by one end to said inductor and by another end to said positive pole of said associated stage of accumulators or to said first capacitor.

6. The apparatus of claim 1, wherein said diode is connected by said anode to said negative pole of said associated stage of accumulators, and wherein said diode is connected by a cathode thereof to a first end of said inductor.

7. The apparatus of claim 1, wherein said control device is further configured to interrupt said power supply current through said inductor by imposing a zero voltage across said terminals of said voltage generator.

8. The apparatus of claim 1, wherein said control device is configured to control a rate of closing of said switch of a charging device associated with a stage of accumulators to be charged in response to application, beforehand, of a voltage to said poles of said voltage generator feeding said charging device.

9. The apparatus of claim 1, wherein said voltage generator comprises at least one switch controlled by said control device, and wherein said voltage generator comprises a decoupling capacitor.

10. The apparatus of claim 9, wherein said voltage generator comprises a configuration selected from the group consisting of a first configuration and a second configuration, wherein said first configuration comprises two controlled switches and two inductors, and wherein said second configuration comprises a switch and a transformer.

11. The apparatus of claim 9, wherein said control device is configured to close and to open said controlled switch of said voltage generator device with a conduction time interval and an opening time interval that are constant during a charging phase.

12. The apparatus of claim 11, wherein said conduction time interval is calculated such that said charging device operates in discontinuous conduction mode independently of voltage levels of said associated stage of accumulators and of a battery during said charging phase.

13. The apparatus of claim 1, further comprising a battery including an elementary module, said elementary module comprising terminals and a plurality of stages of accumulators in series, and a supplementary charging device at said terminals.

14. The apparatus of claim 13, wherein said battery comprises a plurality of elementary modules disposed in series, and wherein said equalization system includes a supplementary charging device at terminals of a predetermined number of said elementary modules.

15. The apparatus of claim 1, further comprising a charging device for a battery stage of accumulators, wherein said equalization system is operably coupled to said charging device.