CN-116134325-B - Battery diagnosis device and method, and battery pack including the same

Abstract

A battery diagnosis apparatus according to an embodiment of the present invention includes a voltage measurement unit configured to measure voltages of respective battery cells among a plurality of battery cells included in a battery module at each voltage measurement section, and a control unit configured to obtain voltage values of the plurality of battery cells from the voltage measurement unit at each voltage measurement section, calculate voltage changes between the obtained voltage values of the plurality of battery cells, calculate a voltage change rate between the calculated plurality of voltage change amounts at a diagnosis section different from the voltage measurement section, and diagnose the battery module based on a preset standard change rate and the calculated one or more voltage change rates.

Inventors

• An Yangzhu
• Cheng Rongzhe

Assignees

• 株式会社LG新能源

Dates

Publication Date

20260508

Application Date

20211228

Priority Date

20201228

Claims (14)

1. 1. A battery diagnosis device, the battery diagnosis device comprising: A voltage measurement unit configured to measure a voltage of each of a plurality of battery cells included in the battery module at each voltage measurement period, and A control unit configured to obtain voltage values of the plurality of battery cells from the voltage measurement unit at each voltage measurement period, calculate voltage variation amounts between the obtained plurality of voltage values of the plurality of battery cells, calculate a voltage variation rate between the calculated plurality of voltage variation amounts at each diagnosis period different from the voltage measurement period, and diagnose the battery module based on one or more of the voltage variation rates calculated up to a current diagnosis period, a preset standard variation rate, and a reference variation rate preset at a previous diagnosis period, Wherein the reference rate of change is preset to a maximum voltage rate of change among one or more voltage rates of change calculated in a previous diagnostic period.
2. 2. The battery diagnosis device according to claim 1, Wherein the control unit is configured to compare magnitudes of the voltage change rate and the standard change rate calculated at the current diagnosis period, and diagnose the state of the battery module based on the comparison result.
3. 3. The battery diagnosis device according to claim 2, Wherein the control unit is configured to diagnose the battery module based on the voltage change rate and the reference change rate preset at a previous diagnosis period when the voltage change rate is equal to or greater than the standard change rate, and Wherein the control unit is configured to diagnose the battery module as a normal module when the voltage change rate is smaller than the standard change rate.
4. 4. The battery diagnosis device according to claim 3, Wherein the control unit is configured to diagnose the battery module as a defective module when the voltage change rate is equal to or greater than the standard change rate and the reference change rate, and Wherein the control unit is configured to diagnose the battery module as the normal module when the voltage change rate is equal to or greater than the standard change rate and less than the reference change rate.
5. 5. The battery diagnosis device according to claim 4, Wherein the control unit is configured to determine a state of the battery module based on at least one of the voltage change rate, the standard change rate, and the reference change rate at each diagnosis period, adjust a preset count value according to the determined state of the battery module, and diagnose the battery module based on the adjusted count value and a preset standard value.
6. 6. The battery diagnosis device according to claim 5, Wherein the control unit is configured to diagnose the battery module as a defective module when the adjusted count value is equal to or greater than the standard value.
7. 7. The battery diagnosis device according to claim 5, Wherein the control unit is configured to decrease the count value when the voltage change rate is smaller than the standard change rate, Wherein the control unit is configured to decrease the count value when the voltage change rate is equal to or greater than the standard change rate and less than the reference change rate, and Wherein the control unit is configured to increase the count value when the voltage change rate is equal to or greater than the standard change rate and the reference change rate.
8. 8. The battery diagnosis device according to claim 7, Wherein if the count value is 0, the count value is not decreased any more.
9. 9. The battery diagnosis device according to claim 1, Wherein the control unit is configured to calculate the voltage variation by calculating dispersion or standard deviation of the plurality of voltage values at each voltage measurement period.
10. 10. The battery diagnosis device according to claim 1, Wherein the diagnostic period is set to be greater than the voltage measurement period.
11. 11. The battery diagnosis device according to claim 1, Wherein the control unit is configured to diagnose each of the plurality of battery cells based on a voltage value corresponding to each of the plurality of battery cells at each voltage measurement cycle.
12. 12. The battery diagnosis device according to claim 11, Wherein the control unit diagnoses a battery cell having a voltage value equal to or greater than a preset upper limit voltage value received from the voltage measurement unit as an overvoltage state, diagnoses a battery cell having the received voltage value equal to or less than a preset lower limit voltage value as a low voltage state, and diagnoses a battery cell having the voltage value less than the upper limit voltage value and exceeding the lower limit voltage value as a normal state.
13. 13. A battery pack including the battery diagnosis device according to any one of claims 1 to 12.
14. 14. A battery diagnosis method, the battery diagnosis method comprising: A voltage measurement step of measuring a voltage of each of a plurality of battery cells included in the battery module at each voltage measurement cycle; A voltage change amount calculation step of calculating a voltage change amount between a plurality of voltage values of the plurality of battery cells at each voltage measurement period; a voltage change rate calculation step of calculating a voltage change rate between the calculated plurality of voltage change amounts at each diagnostic period different from the voltage measurement period, and A battery module diagnosing step of diagnosing the battery module based on one or more of a voltage change rate calculated up to a current diagnostic period, a preset standard change rate, and a reference change rate preset at a previous diagnostic period, Wherein the reference rate of change is configured to preset a maximum voltage rate of change among one or more voltage rates of change calculated in a previous diagnostic period.

Description

Battery diagnosis device and method, and battery pack including the same Technical Field The present application claims priority from korean patent application No. 10-2020-0184947 filed in korea on 12 months 28 of 2020, the disclosure of which is incorporated herein by reference. The present disclosure relates to a battery diagnosis apparatus and method, and more particularly, to a battery diagnosis apparatus and method capable of diagnosing a state of a battery module based on voltage behaviors of a plurality of battery cells included in the battery module. Background In recent years, demands for portable electronic products such as notebook computers, video cameras, mobile phones, and the like have been drastically increased, and electric vehicles, energy storage batteries, robots, satellites, and the like have been greatly developed. Therefore, high-performance batteries allowing repeated charge and discharge are being actively studied. The currently commercially available batteries include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, lithium batteries, and the like. Among them, lithium batteries have been attracting attention because of their almost no memory effect, extremely low self-charging rate, and high energy density as compared with nickel-based batteries. Conventionally, the state of a battery is diagnosed in consideration of the voltage, temperature, and current variation amounts of the battery. Specifically, based on the result of the comparison of the battery voltage with the standard value, whether the battery has an overvoltage and/or a low voltage is monitored. However, conventionally, since the state of the battery is diagnosed according to the voltage of the battery at a specific point in time, the voltage fluctuation trend of the battery cannot be grasped, and it is difficult to diagnose the state of the battery according to the voltage fluctuation trend. Disclosure of Invention Technical problem The present disclosure is directed to solving the problems of the related art, and therefore, the present disclosure is directed to providing a battery diagnosis apparatus and method capable of diagnosing the state of a battery module based on the voltage fluctuation trend of a plurality of battery cells. These and other objects and advantages of the present disclosure will be understood from the following detailed description, and will become more apparent from the exemplary embodiments of the present disclosure. Furthermore, it is to be readily understood that the objects and advantages of the present disclosure may be realized and attained by means of the elements and combinations thereof as shown in the appended claims. Technical proposal A battery diagnosis apparatus according to one aspect of the present disclosure may include a voltage measurement unit configured to measure a voltage of each of a plurality of battery cells included in a battery module at each voltage measurement period (cycle), and a control unit configured to obtain voltage values of the plurality of battery cells from the voltage measurement unit at each voltage measurement period, calculate voltage variation amounts between the obtained plurality of voltage values of the plurality of battery cells, calculate a voltage variation rate (voltage CHANGE RATE) between the calculated voltage variation amounts at each diagnosis period different from the voltage measurement period, and diagnose the battery module based on one or more voltage variation rates calculated up to a current diagnosis period and a preset standard variation rate. The control unit may be configured to compare magnitudes of the voltage change rate and the standard change rate calculated at the current diagnosis period, and diagnose a state of the battery module based on a comparison result. The control unit may be configured to diagnose the battery module based on the voltage change rate and a reference change rate preset at a previous diagnosis period when the voltage change rate is equal to or greater than the standard change rate. The control unit may be configured to diagnose the battery module as a normal module when the voltage change rate is less than the standard change rate. The control unit may be configured to preset a maximum voltage change rate among one or more voltage change rates calculated in a previous diagnostic period as the reference change rate. The control unit may be configured to diagnose the battery module as a defective module when the voltage change rate is equal to or greater than the standard change rate and the reference change rate. The control unit may be configured to diagnose the battery module as the normal module when the voltage change rate is equal to or greater than the standard change rate and less than the reference change rate. The control unit may be configured to determine a state of the battery module based on at least one of the voltage change rate, the standard change rate, a