BATTERY MANAGEMENT SYSTEM AND METHOD

• US 20150035490A1
• Filed: 07/02/2014
• Published: 02/05/2015
• Est. Priority Date: 08/01/2013
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: MAO, Saijun, WIEGMAN, Herman Lucas Norbert, WU, Huiqing, HUANG, Qunjian, MEI, Ying
• Granted Patent: US 9,455,580 B2
• Time in Patent Office: Days
• US Class Current: 320/118
• 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: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A battery system has a battery module including a number M of series-connected batteries. The battery system is further provided with a number N (1<N≦M) of charge equalizers, each of which once connected to a battery, causes the battery to be charged and/or discharged to achieve charge equalization. A control device is configured to determine for each battery if it requires charge equalization based on a state of charge (SOC) of the battery, compare a number L of the batteries that require charge equalization and the number M, and based on the comparison result, cause the battery system to be shut down, or the one or more batteries that require charge equalization to be connected to corresponding charge equalizers. A selective switch module is used for connecting the one or more batteries that require charge equalization to corresponding charge equalizers, respectively.

Claims

1. A battery system, comprising:

a battery module comprising a number M of batteries connected in series;

a number N of charge equalizers, each of which, once connected to a battery in the battery module, causes the battery to be charged and/or discharged for achieving charge equalization, wherein 1<

N≦

M;

a control device configured to;

determine for each battery if it requires charge equalization based on a state of charge (SOC) of the battery,

compare a number L of the batteries that require charge equalization and the number M, and

based on the comparison result, cause the battery system to be shut down, or the one or more batteries that require charge equalization to be connected to corresponding charge equalizers; and

a selective switch module for connecting the one or more batteries that require charge equalization to corresponding charge equalizers, respectively.

2. The battery system of claim 1, wherein the battery is a single battery.

3. The battery system of claim 1, wherein the battery is a collection of parallel connected battery cells.

4. The battery system of claim 1, wherein each of the batteries is coupled with a sensor for measuring voltage across the battery.

5. The battery system of claim 1, wherein the control device is configured to determine a battery as requiring charge equalization if the SOC of the battery is not within a predefined range.

6. The battery system of claim 1, wherein the control device is configured to cause the battery system to be shut down if L>

N and cause the batteries that require charge equalization to be connected to corresponding charge equalizers if L≦

N.

7. The battery system of claim 6, wherein the control device is configured to rank the L batteries in a descending order of how much they require charge equalization and connect the L batteries to the charge equalizers in the descending order, if L≦

N.

8. The battery system of claim 1, wherein the charge equalizer comprises one or more active semiconductor switches, and one or more passive devices.

9. The battery system of claim 1, wherein the switch module comprises one or more selected from the group consisting of metal-oxide power semiconductor transistors, bipolar junction transistors, metal-oxide-semiconductor field-effect transistors, insulated gate bipolar transistors, and relays.

10. The battery system of claim 1, wherein the control device is selected from the group consisting of microprocessors, application specific integrated circuits, digital signal processors, field programmable gate arrays and their combinations.

11. The battery system of claim 1, wherein the battery system comprises at least two said battery modules;

and the charge equalizers and the switch module are provided for each module.

12. A method comprising:

providing a battery system comprising a number M of batteries connected in series and a number N of charge equalizers, wherein 1<

N≦

M;

determining for each battery if it requires charge equalization based on a state of charge (SOC) of the battery;

comparing a number L of batteries that require charge equalization and the number N of the charge equalizers; and

based on the comparison result, shutting down the battery system, or connecting the L batteries that require charge equalization to L charge equalizers to cause the batteries to be charged and/or discharged for achieving charge equalization.

13. The method of claim 12, wherein the determining for each battery if it requires charge equalization comprises determining a battery as requiring charge equalization if the SOC of the battery is not within a predefined range.

14. The method of claim 12, wherein based on the comparison result, the battery system is shut down if L>

N, or the L batteries that require charge equalization are connected to L charge equalizers respectively if L≦

N.

15. The method of claim 14, if L≦

N, further comprising ranking the L batteries that require charge equalization in a descending order of how much they require charge equalization, and the L batteries that require charge equalization are connected to L charge equalizers respectively in the descending order.