Charge equalization system for batteries

• US 9,490,639 B2
• Filed: 02/04/2011
• Issued: 11/08/2016
• Est. Priority Date: 02/05/2010
• Status: Active Grant

• 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: Mercier, Sylvain, Chatroux, Daniel, Dauchy, Julien, Fernandez, Eric
• Primary Examiner(s): Grant, Robert
• Assistant Examiner(s): Trischler, John
• Application Number:
  US13/577,188
• Publication Number:
  US 20130043842A1
• Time in Patent Office: 2,104 Days
• Field of Search: 320/119, 307/148
• US Class Current: 1/1
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 58/13 Maintaining the SoC within a determined range
• 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 10/46 Accumulators structurally combined with charging apparatus circuits for charging H02J7/00
• CPC Class Codes: H01M 2010/4271 Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass 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
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

A battery equalization system has two accumulator stages in series, each including an accumulator, and ±poles, a voltage generator for each accumulator stage, and an associated charging device powered by the generator. The charging device includes an inductor and capacitors. One capacitor connects to the generator'"'"'s positive pole, the other connects to its negative pole, a first diode, whose anode connects to a negative pole of the accumulator stage and whose cathode connects to the first capacitor, a second diode whose anode connects to the negative pole of the accumulator stage and whose cathode connects to the second end of the second capacitor, and a switch connected to the inductor and to the positive pole of the accumulator stage, and a control device that controls the generator, closes the switch and causes the inductor to stores energy and to transfer it to the associated accumulator stage.

Claims

1. An apparatus comprising a battery equalization system for a battery, said battery comprising at least two accumulator stages arranged in series, each of said at least two accumulator stages having a negative pole, a positive pole, and at least one accumulator placed between said negative pole and said positive pole;

said battery equalization system comprising;

a voltage generator comprising a positive terminal and a negative terminal and configured to apply a voltage between said positive terminal and said negative terminal;

for each accumulator stage, a charging device, wherein each accumulator stage is associated with its own charging device, powered by said voltage generator, said charging device comprising at least one inductor, a first capacitor, a second capacitor, a first diode, a second diode, and a switch, wherein said first capacitor has a first end connected to a terminal of said voltage generator and a second end linked to said at least one inductor, wherein said second capacitor has a first end connected to a terminal of said voltage generator and a second end linked to said at least one inductor, wherein said first diode has an anode connected to said negative pole of the accumulator stage and a cathode connected to said second end of said first capacitor, wherein said second diode has an anode connected to said negative pole of the accumulator stage and a cathode connected to said second end of said second capacitor, wherein at least one diode in said charging device has an anode connected to said negative pole of the accumulator stage and has a cathode connected to one end of said at least one inductor, so as to allow, when said at least one diode is on, a charging current to flow through the accumulator stage, said at least one diode and said at least one inductor, and wherein said switch is linked to said at least one inductor and linked to a pole of the accumulator stage, such that said switch is connected in series with one of said at least one inductor and one of said first and second capacitors of said charging device between a terminal of said voltage generator and a pole of the accumulator stage; and

a control device, wherein said control device is configured to control each one of the at least two accumulator stages to be charged with the following steps in order;

during a first conduction time interval to close the switch of the charging device associated with the accumulator stage to be charged and to apply a positive voltage between said terminals of said voltage generator such that a current passes from said positive terminal through said first capacitor, said at least one inductor, the accumulator stage associated to said charging device, and said second capacitor to said negative terminal;

said switch being passed through by an increasing power supply current originating from said voltage generator and that said at least one inductor stores energy;

during a freewheel phase, upon completion of said first conduction time interval, by opening the switch of the charging device associated with the accumulator stage to be charged, interrupting said power supply current through said at least one inductor and allow transfer of said energy stored in said at least one inductor to the accumulator stage to be charged by circulation of a decreasing charging current through said at least one diode in said charging device and said at least one inductor, a zero voltage or no voltage being imposed on said positive terminal and said negative terminal by the voltage generator; and

during a second conduction time interval, to close the switch of the charging device associated with the accumulator stage to be charged and to apply a negative voltage between said terminals of said voltage generator such that a current passes in opposite direction with respect to the first conduction time interval from said negative terminal through said second capacitor, the accumulator stage to be charged, said at least one inductor, and said first capacitor to said positive terminal;

said switch being passed through by an increasing power supply current originating from said voltage generator and that said at least one inductor stores energy.

2. The apparatus of claim 1, wherein said first capacitor has a first end connected to said positive terminal of said voltage generator, and wherein said second capacitor has a first end connected to said negative terminal of said voltage generator.

3. The apparatus of claim 1, wherein said switch comprises a first end and a second end, and wherein said switch is connected by said first end to said at least one inductor and by said second end to said positive pole of said associated accumulator stage.

4. The apparatus of claim 1, wherein the charging device of each of said at least two accumulator stages comprises a first inductor, a second inductor, a first switch and a second switch, wherein said first inductor has a first end connected to a second end of said first capacitor and to said cathode of said first diode, wherein said second inductor has a first end connected to a second end of said second capacitor and to said cathode of said second diode, and wherein said first switch is connected to said first inductor and said second switch is connected to said second inductor.

5. The apparatus of claim 1, wherein the charging device of each of said at least two accumulator stages is configured to operate under discontinuous conduction, independently of voltage levels of said associated accumulator stage and of said battery during a charging phase thereof.

6. The apparatus of claim 1, wherein the at least one accumulator of each of said at least two accumulator stages are of a lithium-ion type.

7. The apparatus of claim 1, wherein said battery comprises super-capacitors.

8. The apparatus of claim 1, wherein the charging device of each of said at least two accumulator stages comprises a first inductor, a second inductor, and switch, wherein said first inductor has a first end connected to a second end of said first capacitor and to said cathode of said first diode, wherein said second inductor has a first end connected to a second end of said second capacitor and to said cathode of said second diode, and wherein said switch is connected to said first and second inductors.

9. The apparatus of claim 8, wherein said first diode is connected by said anode thereof to said negative pole of said associated accumulator stage and by said cathode thereof to said second end of said first capacitor and to one end of said first inductor thereby allowing, when said first diode is on, a circulation of a charging current through said associated accumulator stage, said first diode, and said first inductor.

10. The apparatus of claim 8, wherein said second diode is connected by said anode thereof to said negative pole of said-associated accumulator stage and by said cathode thereof to said second end of said second capacitor and to one end of said second inductor so as to allow, when said second diode is on, a circulation of a charging current through said associated accumulator stage, said second diode, and said second inductor.

11. The apparatus of claim 1, further comprising a third diode, said third diode being connected by a cathode thereof to said first end of said at least one inductor and by an anode thereof to said cathode of said first diode, and a fourth diode connected by a cathode thereof to said first end of said at least one inductor and by an anode thereof to said cathode of said second diode.

12. The apparatus of claim 11, wherein

said charging device comprises a first inductor, a second inductor, wherein

said first inductor has a first end connected to a second end of said first capacitor and to said cathode of said first diode, wherein

said second inductor has a first end connected to a second end of said second capacitor and to said cathode of said second diode, wherein

said third diode is connected to said first inductor, and wherein

said fourth diode is connected to said second inductor.

13. The apparatus of claim 12, wherein the charging device of each of said at least two accumulator stages further comprises a fifth diode connected by a cathode thereof to said first end of said first inductor and by an anode thereof to said negative pole of said associated accumulator stage, and a sixth diode connected by a cathode thereof to said first end of said second inductor and by an anode thereof to said negative pole of said associated accumulator stage.

14. The apparatus of claim 11, wherein said third diode and said fourth diode are connected to said at least one inductor.

15. The apparatus of claim 14, wherein the charging device of each of said at least two accumulator stages further comprises a fifth diode connected by a cathode thereof to said first end of said at least one inductor and by an anode thereof to said negative pole of said associated accumulator stage.

16. An apparatus comprising a battery equalization system for a battery, said battery comprising at least two accumulator stages arranged in series, each of said at least two accumulator stages having a negative pole, a positive pole, and at least one accumulator placed between said negative pole and said positive pole;

said battery equalization system comprising;

a voltage generator comprising a positive terminal and a negative terminal and configured to apply a voltage between said positive terminal and said negative terminal;

for each accumulator stage, a charging device, wherein each accumulator stage is associated with its own charging device, powered by said voltage generator, said charging device comprising a first inductor and a second inductor, a first capacitor, a second capacitor, a first diode, a second diode, a third diode, a fourth diode, a fifth diode, a sixth diode and a switch, wherein said first capacitor has a first end connected to a terminal of said voltage generator and a second end linked to said first inductor, wherein said second capacitor has a first end connected to a terminal of said voltage generator and a second end linked to said second inductor, wherein said first diode has an anode connected to said negative pole of the accumulator stage and a cathode connected to said second end of said first capacitor, wherein said second diode has an anode connected to said negative pole of the accumulator stage and a cathode connected to said second end of said second capacitor, wherein said third diode is mounted in series between said first capacitor and said first inductor and has an anode connected to the second end of said first capacitor and the cathode of the first diode and a cathode connected to a first end of said first inductor, wherein said fourth diode is mounted in series between said second capacitor and said second inductor and has an anode connected to the second end of said second capacitor and the cathode of the second diode and a cathode connected to a first end of said second inductor, said fifth diode being connected by a cathode thereof to said first end of said first inductor and to the cathode of said third diode and by an anode thereof to said negative pole of the accumulator stage, and a sixth diode connected by a cathode thereof to said first end of said second inductor and to the cathode of said fourth diode and by an anode thereof to said negative pole of the accumulator stage, wherein a first end of said switch charging device is linked to a second end of said first inductor and a second end of said second inductor and a second end of said switch is linked to a pole of said associated accumulator stage; and

a control device, wherein said control device is configured to control each one of the at least two accumulator stages to be charged with the following steps in order;

during a first conduction time interval to close the switch of the charging device associated with the accumulator stage to be charged and to apply a positive voltage between said terminals of said voltage generator such that a current passes from said positive terminal through said first capacitor, said third diode, said first inductor, the accumulator stage to be charged, said second diode and said second capacitor to said negative terminal;

said switch being passed through by an increasing power supply current originating from said voltage generator and that said first inductor stores energy;

during a freewheel phase, upon completion of said first conduction time interval, by opening the switch of the charging device of the accumulator to be charged, interrupting said power supply current through said first inductor and allow transfer of said energy stored in said first inductor to the accumulator stage to be charged by circulation of a decreasing charging current through said fifth diode in said charging device and said first inductor, a zero voltage or no voltage being imposed on said positive terminal and said negative terminal by the voltage generator,

during a second conduction time interval, to close the switch of the charging device associated with the accumulator stage to be charged and to apply a negative voltage between said terminals of said voltage generator such that a current passes in opposite direction with respect to the first conduction time interval from said negative terminal through said second capacitor, said fourth diode, said second inductor, the accumulator stage to be charged, said first diode and said first capacitor to said positive terminal;

said switch being passed through by an increasing power supply current originating from said voltage generator and that said second inductor stores energy,

during a freewheel phase, upon completion of said second conduction time interval, by opening the switch of the charging device of the accumulator stage to be charged, interrupting said power supply current through said second inductor and allow transfer of said energy stored in said second inductor to the accumulator stage to be charged by circulation of a decreasing charging current through said sixth diode in the charging device of the accumulator stage to be charged and said second inductor, a zero voltage or no voltage being imposed on said positive terminal and said negative terminal by the voltage generator.

17. An apparatus comprising a battery equalization system for a battery, said battery comprising at least two accumulator stages arranged in series, each of said at least two accumulator stages having a negative pole, a positive pole, and at least one accumulator placed between said negative pole and said positive pole;

said battery equalization system comprising;

a voltage generator comprising a positive terminal and a negative terminal and configured to apply a voltage between said positive terminal and said negative terminal;

for each accumulator stage, a charging device, wherein each accumulator stage is associated with its own charging device, powered by said voltage generator, said charging device comprising a single inductor, a first capacitor, a second capacitor, a first diode, a second diode, a third diode, a fourth diode, a fifth diode, and a switch, wherein said first capacitor has a first end connected to a terminal of said voltage generator and a second end linked to said single inductor, wherein said second capacitor has a first end connected to a terminal of said voltage generator and a second end linked to said single inductor, wherein said first diode has an anode connected to said negative pole of the accumulator stage and a cathode connected to said second end of said first capacitor, wherein said second diode has an anode connected to said negative pole of the accumulator stage and a cathode connected to said second end of said second capacitor, wherein said third diode is mounted in series between said first capacitor and said single inductor and has an anode connected to the second end of said first capacitor and the cathode of the first diode and a cathode connected to said first end of said single inductor, wherein said fourth diode is mounted in series between said second capacitor and said single inductor and has an anode connected to the second end of said second capacitor and the cathode of the second diode and a cathode connected to a first end of said single inductor, said fifth diode being connected by a cathode thereof to said first end of said single inductor and by an anode thereof to said negative pole of the accumulator stage, wherein a first end of said switch is linked to a second end of said single inductor and a second end of said switch is linked to a pole of said associated accumulator stage; and

a control device, wherein said control device is configured to control each one of the at least two accumulator stages to be charged with the following steps in order;

during a first conduction time interval to close the switch of a charging device associated with an accumulator stage to be charged and to apply a positive voltage between said terminals of said voltage generator such that a current passes from said positive terminal through said first capacitor, said third diode, said single inductor, accumulator stage to be charged, said second diode and said second capacitor to said negative terminal, said switch being passed through by an increasing power supply current originating from said voltage generator and that said single inductor stores energy,

during a freewheel phase, upon completion of said first conduction time interval, by opening the switch of the charging device of the accumulator to be charged, interrupting said power supply current through said single inductor and allow transfer of said energy stored in said single inductor to the accumulator stage to be charged by circulation of a decreasing charging current through said fifth diode in the charging device of the accumulator stage to be charged and said single inductor, a zero voltage or no voltage being imposed on said positive terminal and said negative terminal by the voltage generator,

during a second conduction time interval, to close the switch of the charging device associated with the accumulator stage to be charged and to apply a negative voltage between said terminals of said voltage generator such that a current passes in opposite direction with respect to the first conduction time interval from said negative terminal through said second capacitor, said fourth diode, the accumulator stage to be charged, said single inductor, said first diode and said first capacitor to said positive terminal;

said switch being passed through by an increasing power supply current originating from said voltage generator and that said single inductor stores energy; and

during a freewheel phase, upon completion of said second conduction time interval, by opening the switch of the charging device of the accumulator stage to be charged, interrupting said power supply current through said single inductor and allow transfer of said energy stored in said single inductor to the accumulator stage to be charged by circulation of a decreasing charging current through said fifth diode in said charging device and said single inductor, a zero voltage or no voltage being imposed on said positive terminal and said negative terminal by the voltage generator.