Battery fault detection with saturating transformers

• US 8,570,047 B1
• Filed: 08/12/2010
• Issued: 10/29/2013
• Est. Priority Date: 02/12/2009
• Status: Active Grant

• Current Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Original Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Inventors: Davies, Francis J., Graika, Jason R.
• Primary Examiner(s): Dunn, Drew A
• Assistant Examiner(s): PELTON, NATHANIEL R
• Application Number:
  US12/855,384
• Time in Patent Office: 1,174 Days
• Field of Search: 324/434
• US Class Current: 324/434
• CPC Class Codes: G01R 31/382 Arrangements for monitoring battery or accumulator variables, e.g. SoC
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
• CPC Class Codes: H01M 10/4207 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/482 for several batteries or cells simultaneously or sequentially
• 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

Abstract

A battery monitoring system utilizes a plurality of transformers interconnected with a battery having a plurality of battery cells. Windings of the transformers are driven with an excitation waveform whereupon signals are responsively detected, which indicate a health of the battery. In one embodiment, excitation windings and sense windings are separately provided for the plurality of transformers such that the excitation waveform is applied to the excitation windings and the signals are detected on the sense windings. In one embodiment, the number of sense windings and/or excitation windings is varied to permit location of underperforming battery cells utilizing a peak voltage detector.

Claims

1. An apparatus to monitor a plurality of battery cells, said plurality of battery cells being operably connected to each other, comprising:

a plurality of transformers;

a plurality of battery windings operably associated with said plurality of transformers wherein said plurality of battery cells is operably connected to said plurality of battery windings;

a plurality of first windings operably associated with said plurality of transformers;

at least one waveform generator capable of producing a waveform, wherein said at least one waveform generator is operably connected to said plurality of first windings, wherein said plurality of first windings is capable of receiving said waveform;

a plurality of saturable transformer operably associated said plurality of transformers, said waveform being operable to drive said plurality of saturable transformer cores from being magnetically saturated in one direction saturated in an opposite direction; and

at least one signal detector operably connected with said plurality of transformers to detect a signal produced by said plurality of transformers responsively to said waveform to thereby monitor said plurality of battery cells,

wherein said plurality of saturable transformers cores are magnetically saturated by said waveform in a predetermined direction.

2. The apparatus of claim 1, further comprising a plurality of second windings operably associated with said plurality of transformers wherein said at least one signal detector is operably connected to said plurality of second windings.

3. The apparatus of claim 2, wherein said plurality of second windings comprise a predetermined different numbers of turns for a predetermined plurality of transformers.

4. The apparatus of claim 3, wherein said at least one signal detector is operable for detecting peak voltages of said signal to distinguish between said plurality of battery cells for underperformance of said plurality of battery cells.

5. The apparatus of claim 4, wherein each of said plurality of second windings comprises a unique number of turns relative to each other.

6. The apparatus of claim 2, wherein said plurality of second windings for said plurality of transformers are connected in series with each other.

7. The apparatus of claim 1, wherein said plurality of first windings for said plurality of transformers are connected in series with each other.

8. The apparatus of claim 1, further comprising a plurality of interconnections between said plurality of battery cells which electrically connect at least a portion of said battery cells in parallel with each other.

9. The apparatus of claim 1, further comprising a plurality of interconnections between said plurality of battery cells which electrically connect at least a portion of said plurality of battery cells in series with each other.

10. The apparatus of claim 1, further comprising four connections or less to electrically connect to each of said plurality of transformers and to said at least one waveform generator and said at least one signal detector.

11. The apparatus of claim 1, further comprising two connections or less to electrically connect to each of said plurality of transformers and to said at least one waveform generator and said at least one signal detector.

12. A method for monitoring a plurality of battery cells comprising the steps of:

providing a plurality of transformers comprising a plurality of battery windings and a plurality of first windings;

electrically connecting a said plurality of transformers to said plurality of battery cells comprising electrically connecting said plurality of battery windings to said plurality of battery cells;

electrically connecting at least one waveform generator to said plurality of transformers comprising electrically connecting said waveform generator to said plurality of first windings to produce a waveform in said plurality of transformers;

utilizing said waveform to drive a plurality of saturable cores operably associated with said plurality of transformers from being magnetically saturated in one direction to being magnetically saturated in an opposite direction; and

detecting a signal in said plurality of transformers responsively to said waveform indicative of at least one underperforming battery cell within said plurality of battery cells.

13. The method of claim 12, further comprising providing a plurality of second windings operably associated with said plurality of transformers and wherein said step of detecting a signal further comprises electrically connecting a signal detector to said plurality of second windings.

14. The method of claim 13, further comprising the step of varying a number of turns of said plurality of second windings operably associated with said plurality of transformers to locate said at least one underperforming battery cell within said plurality of battery cells.

15. An apparatus to monitor a plurality of battery cells, said plurality of battery cells being operably connected to each other, comprising:

a plurality of transformers operably associated with a plurality of battery windings and operably connected to said plurality of battery cells wherein said plurality of battery cells is operably connected to said plurality of battery windings;

a plurality of first windings operably associated with said plurality of transformers;

at least one waveform generator capable of producing a waveform, wherein said plurality of first windings is operably connected to said at least one waveform generator;

a plurality of saturable transformer cores operably associated with said plurality of transformers, said waveform being operable to drive said plurality of saturable transformer cores from being magnetically saturated in one direction to being magnetically saturated in an opposite direction; and

at least one signal detector connected with said plurality of transformers, wherein said at least one signal detector is capable of detecting at least one underperforming battery cell within said plurality of battery cells,

wherein said plurality of saturable transformers cores are magnetically saturated by said waveform in a predetermined direction.

16. The apparatus of claim 15, further comprising a plurality of second windings operably associated with said plurality of transformers wherein said at least one signal detector is operably connected to said plurality of second windings, said plurality of second windings comprising different numbers of turns for different of said plurality of transformers.

17. The apparatus of claim 15, further comprising a plurality of transformer cores operably associated with said plurality of transformers, wherein each transformer core has a mass of less than 10 grams.