APPARATUS FOR DETECTING FAULTS IN BATTERY SYSTEM

• US 20140236509A1
• Filed: 11/15/2013
• Published: 08/21/2014
• Est. Priority Date: 02/21/2013
• Status: Abandoned Application

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: Kim, Jong-Hoon
• Application Number:
  US14/082,036
• Publication Number:
  US 20140236509A1
• Time in Patent Office: Days
• US Class Current: 702/63
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: G01R 31/385 Arrangements for measuring battery or accumulator variables for monitoring G01R31/382

Abstract

An apparatus for detecting a fault in a battery system, the apparatus including: a voltage detector configured to receive a voltage signal from the battery system and to digitize the voltage signal to generate voltage data; a discrete wavelet transformer configured to receive the voltage data and to perform a discrete wavelet transformation of the voltage data to generate transformation data; a statistical processor configured to receive the transformation data and to process the transformation data to generate statistical data, the statistical data including an average value of the transformation data; and a fault diagnosing unit configured to detect the fault in the battery system based on the statistical data and to transmit a fault signal when the fault is detected.

Claims

1. An apparatus for detecting a fault in a battery system, the apparatus comprising:

a voltage detector configured to receive a voltage signal from the battery system and to digitize the voltage signal to generate voltage data;

a discrete wavelet transformer configured to receive the voltage data and to perform a discrete wavelet transformation of the voltage data to generate transformation data;

a statistical processor configured to receive the transformation data and to process the transformation data to generate statistical data, the statistical data comprising an average value of the transformation data; and

a fault diagnosing unit configured to detect the fault in the battery system based on the statistical data and to transmit a fault signal when the fault is detected.

2. The apparatus of claim 1,

wherein the transformation data comprises j levels of frequency component data, j being a positive real number, and

wherein the statistical processor is configured to receive the j levels of frequency component data as the transformation data and to calculate absolute values of the j levels of the frequency component data to generate magnitude values of each of the j levels of the frequency component data.

3. The apparatus of claim 2, wherein the fault diagnosing unit is configured to compare the magnitude values with a reference value to detect the fault, and to detect the fault if at least one of the magnitude values is greater than the reference value.

4. The apparatus of claim 3, wherein the reference value is set to an initialization reference value.

5. The apparatus of claim 4, wherein the statistical processor is configured to:

calculate an average of the magnitude values to generate the average value;

multiply the average value by a scaler to generate a scaled value;

compare the scaled value to the reference value; and

set the reference value to the scaled value when the scaled value is greater than the reference value.

6. The apparatus of claim 5, wherein the scaler is about 2 to about 5.

7. The apparatus of claim 2, further comprising a maximum value extractor,

wherein the statistics processor is configured to calculate an average of the magnitude values to generate the average value,

wherein the maximum value extractor is configured to:

receive the magnitude values and the average value;

calculate maximum values of the magnitude values of each of the j levels of the frequency component data corresponding to a first time period to generate maximum magnitude values; and

calculate a maximum value of the average value corresponding to the first time period to generate a maximum average value, and

wherein the fault diagnosing unit is configured to;

receive the maximum magnitude values and the maximum average value;

individually compare ratios of each of the maximum magnitude values to the maximum average value; and

detect the fault if at least one of the ratios is greater than a threshold value.

8. The apparatus of claim 7, wherein the threshold value is a value between about 2 and about 5.

9. The apparatus of claim 2, wherein the fault signal comprises information corresponding to which of the j levels of frequency component data the fault was detected in or to a severity of the fault.

10. The apparatus of claim 1, wherein the voltage detector is configured to digitize the voltage signal to generate the voltage data at a sample rate of about 1 sample per second to about 10 samples per second.

11. The apparatus of claim 1, wherein the discrete wavelet transformation is based on a Daubechies 3 wavelet.

12. A method for detecting a fault in a battery, the method comprising:

receiving a voltage signal from a battery system;

digitizing the voltage signal to generate voltage data;

performing a discrete wavelet transformation on the voltage data to generate transformation data;

processing the transformation data to generate statistical data, the statistical data comprising an average value of the transformation data;

analyzing the statistical data to detect the fault; and

transmitting a fault signal when the fault is detected.

13. The method of claim 12,

wherein the transformation data comprises one or more frequency component data,

wherein the processing of the transformation data to generate the statistical data comprises calculating absolute values of the one or more frequency component data, the statistical data further comprising the absolute values, and

wherein the analyzing of the statistical data to detect the faults comprises:

comparing the absolute values with a reference value; and

detecting the fault when at least one of the absolute values is greater than the reference value.

14. The method of claim 13, further comprising initializing the reference value to a predetermined value.

15. The method of claim 14, further comprising:

calculating the average value based on the absolute values;

scaling the average value by a scaler to generate a scaled average value;

comparing the scaled average value with the reference value; and

setting the scaled average value as the reference value when the scaled average value is greater than the reference value.

16. The method of claim 12,

wherein the transformation data comprises one or more frequency component data,

wherein the processing of the transformation data to generate the statistical data comprises:

calculating absolute values of the one or more frequency component data, the statistical data further comprising the absolute values; and

calculating the average value based on the absolute values,

wherein the analyzing of the statistical data to detect the faults comprises;

calculating maximum absolute values of the absolute values corresponding to a first time period;

calculating a maximum average value of the average value corresponding to the first time period;

calculate ratios of the maximum absolute values to the maximum average value; and

detecting the fault when at least one of the ratios exceeds a reference value.

17. An energy storage system comprising:

a power conversion system configured to convert a first power to a second power;

a battery system configured to store and supply the second power, the battery system comprising;

a plurality of battery cells coupled together;

a terminal coupled to a first battery cell of the battery cells;

a switch coupled to the terminal and the power conversion system; and

a battery management system comprising;

a voltage detector configured to receive a voltage signal from the battery cells and to digitize the voltage signal to generate voltage data;

a discrete wavelet transformer configured to receive the voltage data and to perform a discrete wavelet transformation of the voltage data to generate transformation data;

a statistical processor configured to receive the transformation data and to process the transformation data to generate statistical data, the statistical data comprising an average value of the transformation data; and

a fault diagnosing unit configured to detect a fault in the battery system based on the statistical data and to transmit a fault signal when the fault is detected,

wherein the switch is configured to couple the battery cells with the power conversion system according to the fault signal.

18. The energy storage system of claim 17, wherein the voltage signal corresponds to a voltage at the terminal or a cell voltage of one of the battery cells.