Charge balance system and method

Patent metadata

Field	Value
Publication number	US-9403443-B2
Application number	US-201414154676-A
Country	US
Kind code	B2
Filing date	Jan 14, 2014
Priority date	Jan 14, 2014
Publication date	Aug 2, 2016
Grant date	Aug 2, 2016

Abstract

A power system may perform charge balancing for a vehicle. The power system may include a battery including a plurality of modules, each module including a cell and associated resistive circuitry. The system may also include at least one controller configured to, in response to a cell achieving a threshold voltage and/or SOC, activate the associated resistive circuitry for the cell and reduce a charge current applied to the battery to prevent the cell from acquiring additional charge.

First claim

What is claimed is:

1. A vehicle charge balancing power system comprising:
a battery including a plurality of modules, each module including a cell and associated resistive circuitry having a predefined resistance; and
at least one controller configured to, in response to a cell achieving a threshold voltage, activate the associated resistive circuitry for the cell and reduce a charge current applied to the battery to no greater than the threshold voltage divided by the predefined resistance.

2. The power system of claim 1 , further comprising an adjustable power source configured to provide the charge current to the battery, wherein the at least one controller is further configured to command the power source to reduce the charge current applied to the battery.

3. The power system of claim 2 , wherein the adjustable power source includes an on-board solar panel, an on-board generator, an off-board solar panel, or an off-board charging device.

4. The power system of claim 1 , wherein the at least one controller is further configured to disable the charge current applied to the battery in response to the cells of the battery being balanced and the battery being fully charged.

5. The power system of claim 1 , wherein the at least controller is further configured to reduce the charge current applied to the battery to less than the threshold voltage divided by the predefined resistance, thereby allowing discharge of the cells of the battery achieving the threshold voltage and charge of at least one other cell of the battery.

6. The power system of claim 1 , wherein the at least controller is further configured to reduce the charge current applied to the battery to the threshold voltage divided by the predefined resistance, thereby allowing neither charge nor discharge of the cells of the battery achieving the threshold voltage and charge of at least one other cell of the battery.

7. The power system of claim 1 , wherein the threshold voltage is a nominal charged cell voltage or has a value less than the nominal charged cell voltage to allow for absorption of energy from regenerative braking.

8. A method for performing charge balancing for a vehicle comprising:
monitoring state of charge of a battery including a plurality of modules, each module including a cell and associated resistive circuitry having a predefined resistance;
activating the associated resistive circuitry for one of the cells in response to the one of the cells achieving a threshold voltage; and
reducing a charge current applied to the battery to no greater than the threshold voltage divided by the predefined resistance to prevent the one of the cells from acquiring additional charge.

9. The method of claim 8 , further comprising commanding an adjustable power source providing the charge current to the battery to reduce the charge current applied to the battery.

10. The method of claim 9 , wherein the adjustable power source includes an on-board solar panel, an on-board generator, an off-board solar panel, or an off-board charging device.

11. The method of claim 8 , wherein the at least one controller is further configured to disable the charge current applied to the battery in response to the cells of the battery being balanced and the battery being fully charged.

12. The method of claim 8 , further comprising reducing the charge current applied to the battery to less than the threshold voltage divided by the predefined resistance, thereby allowing discharge of the cells of the battery achieving the threshold voltage and charge of at least one other cell of the battery.

13. The method of claim 8 , further comprising reducing the charge current applied to the battery to the threshold voltage divided by the predefined resistance, thereby allowing neither charge nor discharge of the cells of the battery achieving the threshold voltage and charge of at least one other cell of the battery.

14. The method of claim 8 , further comprising setting the threshold voltage to a nominal charged cell voltage or a value less than the nominal charged cell voltage to allow for absorption of energy from regenerative braking.

15. A vehicle comprising:
an electric machine configured to generate motive power for the vehicle;
a battery including a plurality of modules, each module including a cell configured to store energy for the electric machine and associated resistive circuitry having a predefined resistance; and
at least one controller configured to, in response to one of the cells achieving a threshold voltage, activate the associated resistive circuitry for the one of the cells and reduce a charge current applied to the battery to no greater than the threshold voltage divided by the predefined resistance to prevent the one of the cells from acquiring additional charge.

16. The vehicle of claim 15 , further comprising an adjustable power source configured to provide the charge current to the battery, wherein the at least one controller is further configured to command the power source to reduce the charge current applied to the battery.

17. The vehicle of claim 16 , wherein the adjustable power source includes an on-board solar panel, an on-board generator, an interface for receiving power from an off-board solar panel, or an interface for receiving power from an off-board charging device.

18. The vehicle of claim 15 , wherein the at least one controller is further configured to disable the charge current applied to the battery in response to the cells of the battery being balanced and the battery being fully charged.

19. The vehicle of claim 15 , wherein the at least controller is further configured to reduce the charge current applied to the battery to less than the threshold voltage divided by the predefined resistance, thereby allowing discharge of the cells of the battery achieving the threshold voltage and charge of at least one other cell of the battery.

20. The vehicle of claim 15 , wherein the at least controller is further configured to reduce the charge current applied to the battery to the threshold voltage divided by the predefined resistance, thereby allowing neither charge nor discharge of the cells of the battery achieving the threshold voltage and charge of at least one other cell of the battery.

Assignees

• Ford Global Tech Llc

Inventors

• Loftus Michael Edward
• Syed Fazal Urrahman
• Schamber Michael
• Nallapa Venkatapathi Raju
• Kozarekar Shailesh Shrikant

Classifications

• H02J2105/37

  exchanging power with electric vehicles [EV] or with hybrid electric vehicles [HEV] · CPC title

• H02J7/54

  Passive balancing, e.g. using resistors or parallel MOSFETs · CPC title

• H02J7/52

  for charge balancing, e.g. equalisation of charge between batteries · CPC title

• H02J7/50

  acting upon multiple batteries simultaneously or sequentially · CPC title

• B60K6/00

  Arrangement or mounting of plural diverse prime-movers for mutual or common propulsion, e.g. hybrid propulsion systems comprising electric motors and internal combustion engines · CPC title