Response to detection of an overdischarge event in a series connected battery element

• US 9,318,901 B2
• Filed: 11/30/2012
• Issued: 04/19/2016
• Est. Priority Date: 11/30/2012
• Status: Active Grant

• Current Assignee: Tesla Inc.
• Original Assignee: Tesla Motors Incorporated (Tesla Inc.)
• Inventors: LePort, Francisco, Kohn, Scott Ira
• Primary Examiner(s): Tso, Edward
• Assistant Examiner(s): Piggush, Aaron
• Application Number:
  US13/690,341
• Publication Number:
  US 20140152260A1
• Time in Patent Office: 1,236 Days
• Field of Search: 320/118, 320/122, 320/134, 320/136, 320/162
• US Class Current: 1/1
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00306 Overdischarge protection
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]

Abstract

A system and method for identifying and responding to exceptional charge events of series-connected energy storage elements.

Claims

1. A microprocessor-implemented response system for an exceptional charge event including an overdischarge of a particular one battery element in an energy storage system having a plurality of series-connected battery elements, comprising:

a first charge imbalance detection system monitoring, using the microprocessor, the energy storage system for a charge imbalance using a first detection modality, said first charge imbalance detection system initiating a reduction of said charge imbalance using a first response modality;

a second charge imbalance detection system monitoring, using the microprocessor, the energy storage system for the overdischarge of the particular one battery element using a second detection modality different from said first detection modality; and

a remediation system initiating a response to said overdischarge using a second response modality different from said first response modality, said response decreasing a risk associated with said overdischarge;

wherein said first detection modality includes a measurement of a voltage level of each battery element of the plurality of battery elements establishing a plurality of voltage imbalances between individual ones of the plurality of battery elements;

wherein said first response modality includes adjusting said voltage levels to reduce said plurality of voltage imbalances; and

wherein said second detection modality includes a statistical evaluation of a parameter of each battery element.

2. The microprocessor-implemented response system of claim 1 wherein said response includes inhibiting any charging event until the energy storage system is serviced.

3. The microprocessor-implemented response system of claim 1 wherein the particular one battery element includes a particular charge storage target and wherein said response includes use of said first response modality to increase said particular charge storage target intentionally creating an imbalance.

4. The microprocessor-implemented response system of claim 1 wherein the ESS includes a charge storage target for the plurality of battery elements and wherein said response includes increasing said charge storage targets.

5. The microprocessor-implemented response system of claim 1 wherein said response includes logging a set of data associated with said overdischarge.

6. The microprocessor-implemented response system of claim 1 wherein the particular one battery element includes an associated gain factor used when discharging the particular one battery element and wherein said response includes an increase to said associated gain factor.

7. The microprocessor-implemented response system of claim 1 wherein the particular one battery element includes an associated voltage offset factor used when discharging the particular one battery element and wherein said response includes an increase to said associated voltage offset factor.

8. The microprocessor-implemented response system of claim 1 wherein the ESS includes an associated maximum current draw used when discharging the plurality of battery elements and wherein said response includes a decrease to an effective current draw less than said associated maximum current draw.