System and method for battery management

Patent metadata

Field	Value
Publication number	US-9425631-B2
Application number	US-201213405970-A
Country	US
Kind code	B2
Filing date	Feb 27, 2012
Priority date	Feb 27, 2012
Publication date	Aug 23, 2016
Grant date	Aug 23, 2016

Abstract

In accordance with an embodiment, a bi-directional charging circuit has a battery coupling node output configured to be coupled to a battery cell, an input coupled to a common node of the battery management system, and a controller coupled to the bi-directional charging circuit. The controller is configured to operate the bi-directional charging circuit in a charging mode to transfer charge from the common node to the battery coupling node, and operate the bi-directional charging circuit in a discharge mode to transfer change from the battery coupling node to the common node.

First claim

What is claimed is:

1. A battery management system comprising:
a plurality of bi-directional charging circuits coupled in parallel, each comprising:
a respective battery coupling node output configured to be coupled to a corresponding battery of a plurality of batteries, and
an input coupled to a common node of the battery management system;

a charge balancing circuit; and
a controller coupled to the plurality of bi-directional charging circuits, the controller configured to:
operate the plurality of bi-directional charging circuits in a charging mode to transfer charge from the common node to the respective battery coupling nodes,
operate the plurality of bi-directional charging circuits in a discharge mode to transfer change from the respective battery coupling nodes to the common node, wherein during the discharge mode the controller controls a respective contributed voltage at the common node to be different from a respective output voltage at the respective battery coupling nodes, independently for each one of the plurality of bi-directional charging circuits, and
operate the charge balancing circuit to adjust the charging and discharging of each of the corresponding plurality of batteries according to a charge level of each of the corresponding plurality of batteries,

wherein each of the plurality of bi-directional charging circuits comprises a bi-directional voltage converter, configured to convert an input voltage into a higher or lower output voltage in either direction, and
wherein each of the plurality of bi-directional charging circuits comprises a series switch, a parallel switch, and a series inductor.

2. The battery management system of claim 1 , wherein the bi-directional voltage converter is a buck-boost converter.

3. The battery management system of claim 1 , wherein the controller is further configured to shut off the series switch to protect at least one of the plurality of batteries.

4. The battery management system of claim 1 , wherein the controller comprises switching outputs coupled to switching inputs of the plurality of bi-directional charging circuits, and wherein the controller activates the switching inputs of the plurality of bi-directional charging circuits in different phases.

5. The battery management system of claim 1 , wherein:
the controller is configured to independently control an output voltage at the common node during the discharge mode; and
the controller is configured to independently control charging of each of the bi-directional charging circuits during the charging mode.

6. The battery management system of claim 5 , wherein the controller is configured to perform charge balancing of the plurality of batteries.

7. The battery management system of claim 1 , wherein each of the bi-directional charging circuits operate in a quasi-resonant conversion mode.

8. A controller for a battery management system comprising:
a plurality of pulse modulators configured to be coupled to a corresponding plurality of parallel bi-directional switching power supplies coupled between a supply rail and a corresponding plurality of batteries, each of the plurality of pulse modulators having switching outputs configured to operate a corresponding bi-directional switching power supply in a charging mode and in a discharging mode;
a supply rail control circuit configured to control a voltage of the supply rail during the discharging mode, wherein controlling the voltage of the supply rail includes controlling each of the bi-directional switching power supplies to provide a respective contributing supply rail voltage sourced from a respective corresponding battery, wherein the respective contributing supply rail voltage of each switching power supply is different from a voltage available at the corresponding battery for each switching power supply;
a charge balancing circuit configured to adjust the charging and discharging of each of the corresponding plurality of batteries according to a charge level of each of the corresponding plurality of batteries; and
a plurality of battery charging control circuits configured to control a charging voltage or charging current to each of the corresponding plurality of batteries during the charging mode,
wherein each of the plurality of bi-directional switching power supplies comprises a bi-directional voltage converter, configured to convert an input voltage into a higher or lower output voltage in either direction, and
wherein each of the plurality of bi-directional charging circuits comprises a series switch, a parallel switch, and a series inductor.

9. The controller of claim 8 , wherein the charge balancing circuit adjusts a switch-on time of each of the plurality of pulse modulators.

10. The controller of claim 9 , wherein:
during the charging mode, the charge balancing circuit adjusts the switch-on time of a pulse modulator according to a difference between a maximum charge level and a remaining charge level of the corresponding battery; and
during the charging mode, the charge balancing circuit adjusts the switch-on time of the pulse modulator according to the remaining charge level of the corresponding battery.

11. The controller of claim 10 , wherein:
during the charging mode, the charge balancing circuit further adjusts the switch-on time of a pulse modulator according to a sum of a difference between a maximum charge level and a remaining charge level across each of the corresponding batteries; and
during the charging mode, the charge balancing circuit further adjusts the switch-on time of a pulse modulator according to a sum of the remaining charge level across each of the corresponding batteries.

12. The controller of claim 8 , wherein the controller is disposed on an integrated circuit.

13. The controller of claim 8 , further comprising the plurality of parallel bi-directional switching power supplies.

14. The controller of claim 13 , wherein each of the plurality of parallel bi-directional switching power supplies comprise at least one switch and at least one inductor.

15. The controller of claim 8 , wherein the controller further comprises switches of the parallel bi-directional switching power supplies.

16. The controller of claim 8 , wherein the controller is disposed within a battery management system of a mobile terminal.

17. The controller for a battery management system of claim 8 , wherein each of the bi-directional voltage converters comprises a bi-directional buck-boost converter.

18. A method of operating a plurality of parallel connected bi-directional power supply circuits that are each coupled to a corresponding battery and to a common power supply node, the method comprising:
operating the plurality of bi-directional power supply circuits in a charge mode, the operating the plurality of bi-directional power supply circuits in the charge mode comprising sequencing switch signals coupled to the bi-directional power supply circuits to transfer charge from the common power supply node to each of the corresponding batteries;
operating the plurality of bi-directional power supply circuits in a discharge mode, operating the plurality of bi-directional power supply circuits in the discharge mode comprising:
sequencing switch signals coupled to the bi-directional power supply circuits to transfer charge from each of the corresponding batteries to the common power supply node, and
controlling a voltage at the common power supply node using feedback, wherein the voltage at the common power supply is controlled to be different from a voltage of each of the

Assignees

• Furtner Wolfgang
• Infineon Technologies Austria Ag

Inventors

• Furtner Wolfgang

Classifications

• H02J7/56 Primary

  Active balancing, e.g. using capacitor-based, inductor-based or DC-DC converters · CPC title

• G06F1/263

  Arrangements for using multiple switchable power supplies, e.g. battery and AC (G06F1/30 takes precedence) · CPC title

• H02J7/0019 Primary

  Electricity · mapped topic

• H02J7/0018

  Electricity · mapped topic