Method and apparatus for estimating state of battery

Patent metadata

Field	Value
Publication number	US-10393819-B2
Application number	US-201414567511-A
Country	US
Kind code	B2
Filing date	Dec 11, 2014
Priority date	Jul 2, 2014
Publication date	Aug 27, 2019
Grant date	Aug 27, 2019

Abstract

A battery state estimation method and apparatus. The apparatus includes a time detector configured to detect a time during which a voltage level of a battery, being partially charged and discharged, changes through a constant current charge. The apparatus also includes a state of health (SoH) information estimator configured to estimate SoH information of the battery with the changed voltage level and the detected time, based on predetermined reference information.

First claim

What is claimed is:

1. A battery information estimation apparatus in a battery management system, the apparatus comprising:
a processor comprising:
a time detector configured to detect respective times during which a measured voltage level of a battery, being partially charged and discharged, changes to correspond to a plurality of predetermined voltage intervals through a constant current charge, the measured voltage level being measured using a sensor; and
a state of health (SoH) information estimator configured to:
determine respective voltage intervals, belonging to measured voltage levels of the battery during the detected respective times, from among the plurality of predetermined voltage intervals included in predetermined reference information,
determine time information corresponding to the detected respective times, from among items of time information included in the predetermined reference information, the items being determined to be mapped to the determined respective voltage intervals, and
estimate state of health (SoH) information of the battery based on a SoH reference value being mapped to the determined time information using reference SoH information included in the predetermined reference information.

2. The apparatus of claim 1 , wherein the time detector comprises:
a voltage detector configured to detect the changed voltage level being measured using the sensor; and
a time measurer configured to measure the respective times during which the measured voltage level changes to correspond to the plurality of predetermined voltage ranges.

3. The apparatus of claim 1 , further comprising:
a charge state determiner configured to determine whether the battery is in a charge state,
wherein the time detector is configured to detect the respective times during which the voltage level changes in response to the charge state determiner determining that the battery is in the charge state.

4. The apparatus of claim 1 , wherein the predetermined reference information comprises reference time information including the items of time information, and comprises the reference SoH information including the SoH reference value.

5. The apparatus of claim 4 , wherein the predetermined reference information indicates a lookup table.

6. The apparatus of claim 4 , wherein the reference time information and the reference SoH information are classified for each cycle in which reference batteries are fully charged and discharged, and the reference batteries includes the battery.

7. The apparatus of claim 4 , wherein the reference time information and the reference SoH information are classified for each charging rate of the battery.

8. The apparatus of claim 4 , wherein the SoH information estimator is configured to detect the respective voltage intervals, being determined to be mapped to the measured voltage levels, from among the plurality of predetermined voltage intervals.

9. The apparatus of claim 8 , wherein the SoH information estimator is configured to extract the determined time information from the reference time information and, extract the SoH reference value from the reference SoH information.

10. The apparatus of claim 8 , wherein in response to the SoH information estimator failing to detect the respective voltage intervals, being determined to be mapped to the changed voltage level, from among the plurality of predetermined voltage intervals, the SoH information estimator is configured to extract a voltage interval mapped to the changed voltage level by interpolating the plurality of predetermined voltage intervals, and extract times mapped to the detected respective times from among the items of time information corresponding to the extracted voltage interval.

11. The apparatus of claim 8 , wherein, in response to the SoH information estimator failing to determine the time information corresponding to or being mapped to the detected respective times from among the items of time information, the SoH information estimator is configured to extract times corresponding to or being mapped to the detected respective times by interpolating the items of time information corresponding to the mapped respective voltage intervals.

12. The apparatus of claim 1 , wherein the SoH information estimator is further configured to prevent the battery from overcharging and overdischarging, and control battery modules in the battery to be in equal charge states by performing cell balancing.

13. The apparatus of claim 1 , wherein the SoH information estimator is further configured to estimate a state of charge (SoC) information and a state of function (SoF) information, wherein the SoC information is information on an amount of charges held in the battery, and the SoF information indicates information on a degree to which the performance of the battery matches a predefined condition.

14. The apparatus of claim 1 , wherein in response to the battery being partially charged and discharged, the SoH information estimator is configured to estimate the SoH information on the battery by detecting a constant current charging time (CCCT) based on the predetermined reference information.

15. The apparatus of claim 1 , wherein the battery is charged at a constant current until the measured voltage level of the battery reaches a predefined voltage level, and
when the measured voltage level of the battery reaches the predefined voltage level, the battery is charged using a constant voltage until a current level reaches a predefined current level.

16. A battery information preprocessing apparatus in a battery management system, the apparatus comprising:
a processor comprising:
a state change information acquirer configured to acquire information about a state change of a battery being fully charged and discharged during cycles, the information about the state change being measured using a sensor and indicating a time consumed during a full cycle of charging and discharging for each cycle of charging the battery at a constant current between two voltage levels, and charging the battery at a constant voltage in response to a higher of the two voltage levels being reached; and
a reference state of health (SoH) information detector configured to detect, based on the information about the state change, reference SoH information corresponding to a degree of degradation of the battery for each of the cycles, the reference SoH information being a ratio between the time consumed during the full cycle of charging and discharging and a time consumed during a first full cycle of charging and discharging, wherein
the processor is configured to generate reference information, using the information about the state change and the reference SoH information, for estimating a SOH of the battery; and

a memory electrically coupled to the processor and configured to store the generated reference information including reference time information and the reference SoH information.

17. The apparatus of claim 16 , wherein the state change information acquirer is configured to acquire information on a capacity change of the battery based on the cycles in which the battery is fully charged and discharged.

18. The apparatus of claim 17 , wherein the reference SoH information detector is configured to operate at a ratio between a capacity of the battery corresponding to the first full charging and discharging and a capacity of the battery corresponding to N th full charging and discharging, N being a number of the cycles, and
extract SoH information of the battery as a ratio of time consumed to charge th

Assignees

• Samsung Electronics Co Ltd

Inventors

• You Kaeweon
• Park Sangdo

Classifications

• G01R31/367

  Software therefor, e.g. for battery testing using modelling or look-up tables · CPC title

• G01R31/392 Primary

  Determining battery ageing or deterioration, e.g. state of health · CPC title