Battery health state calibration system and method, battery module and vehicle

Abstract

The invention provides a battery health state calibration system, a battery health state calibration method, a battery module and a vehicle. The state-of-health calibration system includes a battery management system configured to obtain a current state-of-health value of a battery; the processing module is configured to store the historical health state value and perform credibility detection between the current health state value and the historical health state value, and the battery management system is further configured to change the current health state value into the historical health state value based on a credibility detection result so as to calibrate the current health state value. According to the health state calibration system, whether the health state value of the battery is wrong or not is judged by carrying out credibility detection on the current health state value and the historical health state value, and a proper health state value can be quickly given under the condition that the current health state value is detected to have a problem; and the calibration speed and precision of the health state are improved.

Description

Technical Field

[0001] The present invention relates to the field of vehicles, and more particularly to the field of battery systems for vehicles. More specifically, it relates to a system for calibrating the state of health of a battery, a method for calibrating the state of health, a battery module applying the system for calibrating the state of health, and a vehicle using the method for calibrating the state of health or applying the system for calibrating the state of health. Background Art

[0002] In recent years, new energy vehicles have become increasingly common in life. In new energy vehicles, lithium batteries are usually used as the power source. Due to the particularity of lithium batteries, it is necessary to avoid phenomena such as overcharging, over-discharging, and overheating of the battery during use. For example, when the battery is over-discharged, it will cause serious damage to the battery, affect the performance of the entire battery module, and even cause an explosion. Usually, a BMS (Battery Management System) is used to control the state of the battery, where the state of the battery includes SOC (State-of-Charge), SOH (State-of-Health), SOP (State-of-Power), etc.

[0003] SOH is an indication of the state of the battery's health and lifespan. SOH may affect the battery's quality assurance and the power usage of the vehicle, etc. If there are problems with SOH calibration (such problems are caused by, for example, writing and reading problems of NVM (non-volatile memory), poor software robustness, hacking attacks, etc.), it will bring great inconvenience to users and will require a long time for quality inspection. Precise calibration of SOH can fully understand the current state of the battery, facilitate timely correction of various parameter performance indicators, reduce or avoid the risk factor, and extend the service life of the battery.

[0004] Therefore, it is necessary to improve the calibration accuracy of SOH. Summary of the Invention

[0005] The object of the present invention is to solve the problems existing in the above-mentioned prior art, and provide a method for calibrating the state of health of a battery, which can improve the calibration accuracy of SOH in a cost-effective and reliable manner.

[0006] To this end, according to one aspect of the present invention, a system for calibrating the state of health of a battery is provided. The state-of-health calibration system includes: a battery management system configured to obtain a current state-of-health value of the battery; a processing module configured to store historical state-of-health values and perform a credibility detection between the current state-of-health value and the historical state-of-health values, wherein the battery management system is further configured to change the current state-of-health value to the historical state-of-health value based on the credibility detection result to calibrate the current state-of-health value.

[0007] According to the above technical concept, the present invention may further include any one or more of the following optional forms.

[0008] In some optional forms, the processing module includes a detection unit configured to detect a change rate of the current state-of-health value relative to the historical state-of-health value and compare the change rate with a preset change rate.

[0009] In some optional forms, the detection unit is one of a vehicle controller, a body control module, and a DC-DC converter.

[0010] In some optional forms, the battery management system is configured to: change the current state-of-health value to the historical state-of-health value when the change rate is greater than the preset change rate, and output the current state-of-health value when the change rate is less than or equal to the preset change rate.

[0011] In some optional forms, the battery management system is further configured to: send an alarm signal to the detection unit when the change rate is greater than the preset change rate.

[0012] In some optional forms, the processing module further includes a storage unit configured to store the historical state-of-health value and the current state-of-health value.

[0013] In some optional forms, the storage unit is one of a telematics unit, a ferroelectric random access memory, and a flash memory.

[0014] According to another aspect of the present invention, a method for calibrating the state of health of a battery is provided. The state-of-health calibration method includes: obtaining a current state-of-health value of the battery; performing a credibility detection between the current state-of-health value and the stored historical state-of-health values; and changing the current state-of-health value to the historical state-of-health value based on the credibility detection result to calibrate the current state-of-health value.

[0015] In some alternative forms, performing a credibility detection between the current health state value and the stored historical health state values includes: detecting a change rate of the current health state value relative to the historical health state value, and comparing the change rate with a preset change rate.

[0016] In some alternative forms, changing the current health state value to the historical health state value based on the credibility detection result to calibrate the current state value includes: when the change rate is greater than the preset change rate, changing the current health state value to the historical health state value; when the change rate is less than or equal to the preset change rate, outputting the current health state value.

[0017] In some alternative forms, an alarm signal is sent when the change rate is greater than the preset change rate.

[0018] According to another aspect of the present invention, a battery module is provided, which includes a plurality of batteries and the above-mentioned health state calibration system for the batteries.

[0019] According to another aspect of the present invention, a vehicle is provided, which includes the above-mentioned health state calibration system for the batteries or the above-mentioned battery module, or the vehicle uses the above-mentioned health state calibration method for the batteries to calibrate the health state of the vehicle's batteries.

[0020] The health state calibration system of the present invention determines whether the health state value of the battery is incorrect by performing a credibility detection on the current health state value and the historical health state value, and can quickly give a suitable health state value when it is detected that there is a problem with the current health state value, improving the calibration speed and accuracy of the health state. Description of the Drawings

[0021] Other features and advantages of the present invention will be better understood through the following alternative embodiments described in detail in conjunction with the drawings, where:

[0022] Figure 1 A schematic diagram of a health state calibration system for a battery according to an embodiment of the present invention is shown;

[0023] Figure 2 A schematic flowchart of a health state calibration method for a battery according to an embodiment of the present invention is shown; and

[0024] Figure 3 A schematic flowchart of a health state calibration method for a battery according to another embodiment of the present invention is shown. Detailed Embodiments

[0025] The implementation and use of the embodiments are discussed in detail below. However, it should be understood that the specific embodiments discussed are merely exemplary illustrations of specific ways of implementing and using the present invention, and do not limit the scope of the present invention.

[0026] In addition, the flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of the methods and systems according to various embodiments of the present invention. It should be noted that the functions marked in the blocks may also occur in an order different from that marked in the accompanying drawings. For example, two consecutive blocks shown may actually be executed substantially in parallel, or they may sometimes be executed in the reverse order, depending on the functions involved.

[0027] SOH is a very important parameter of the battery. Currently, the SOH is usually calibrated based on the SOC value and capacity of the battery. For example, when the SOC value is increased from 40% charge to 100% and the battery capacity increases by 45 Ah, then the total capacity of the battery is 75 Ah (45 Ah / 0.6 = 75 Ah). Then, the total capacity of the battery at this time is compared with the available capacity (BOL) when the battery leaves the factory. In the case where the BOL is 100 Ah, it can be obtained that the current SOH value of the battery is 75% (75 Ah / 100 Ah = 75%). The inventors found that the current calibration method for SOH mainly depends on the accuracy of the SOC value and the current sensor for measuring the SOC value. In other words, if the SOC value is inaccurate, the accuracy of the SOH value will be low.

[0028] Refer to Figure 1 , Figure 1 FIG. shows a schematic diagram of a system for calibrating the state of health of a battery according to an embodiment of the present invention.

[0029] A system 100 for calibrating the state of health of a battery according to an embodiment of the present invention generally includes a battery management system (BMS) 110 and a processing module 120. The battery management system 110 is used to obtain the current state of health value of the battery. The processing module 120 is used to receive the current state of health value from the battery management system 110 and perform a credibility detection between the current state of health value and the historical state of health value, where the historical state of health value is stored in the processing module 120. Further, the processing module 120 sends the credibility detection result to the battery management system 110. If the credibility detection fails, the battery management system 110 changes the current state of health value of the battery to the historical state of health value to calibrate the SOH of the battery.

[0030] In this way, the health state calibration system 100 according to the present invention determines whether the SOH of the battery is incorrect by performing a credibility detection between the current health state value and the historical health state value of the battery, and changes the current health state value to the historical health state value when the credibility detection fails. Thus, a suitable health state value can be quickly given, the calibration speed and accuracy of the SOH can be improved, so that the actual health condition of the battery can be more accurately understood, the charging and discharging process of the battery can be better managed, the service life of the battery can be extended, and the risk of battery failure can be reduced.

[0031] Additionally, the historical health state value can be the health state value at the previous moment, and the health state value at the previous moment is the health state value detected by the previous cycle calibration. In some embodiments, the time difference between the health state value at the previous moment and the current health state value can be, for example, 6 hours, 12 hours, 24 hours, etc.

[0032] In some embodiments, the processing module 120 may include a detection unit 121, and the detection unit 121 can perform a credibility detection between the current health state value and the historical health state value. Specifically, the credibility detection includes detecting, by the detection unit 121, the change rate of the current health state value relative to the historical health state value and comparing the change rate with a preset change rate to obtain a credibility detection result, where the preset change rate can be in the range of, for example, 1.5%-2.5%, for example, 2%. It can be understood that the preset change rate is not limited to this and can be changed as needed. In this way, performing the credibility detection by detecting the relative change rate of the SOH (i.e., the change rate of the current health state value relative to the historical health state value) can adapt to changes in different environments. For example, the relative change rate can better capture the effects of different temperatures, loads, and charging states on the battery, so that the health state calibration system 100 can have dynamic adaptability and improve the stability of the credibility detection.

[0033] In some embodiments, the detection unit 121 can be a vehicle control unit (VCU), a body control module (BCM), a DC-DC converter, etc. It can be understood that the detection unit 121 is not limited to this and can be changed as needed as long as it can transmit, calculate, and compare data, etc.

[0034] After the detection unit 121 completes the credibility detection, it sends the detection result to the BMS 110, and the BMS 110 calibrates the current state of health value based on this detection result. Specifically, when the relative change rate is greater than the preset change rate, the credibility detection fails (Credibility_SOH = 0), indicating that the current state of health value is incorrect. At this time, the detection unit 121 sends the historical state of health value to the BMS 110, and the BMS 110 changes the current state of health value to the historical state of health value and outputs the changed SOH for the next cycle of detection. When the relative change rate is less than or equal to the preset change rate, the credibility detection passes (Credibility_SOH = 1), indicating that the current state of health value is correct, and the BMS will output the current state of health value for the next cycle of detection. In this way, the state of health calibration system 100 can quickly calibrate the SOH and give a suitable SOH value when the SOH calibration fails, improving the calibration accuracy and efficiency of the SOH.

[0035] Additionally, when the relative change rate is greater than the preset change rate, that is, when the credibility detection fails, the BMS 110 can generate an alarm signal. For example, the BMS can light up an alarm light, which can be set on, for example, the vehicle dashboard. After receiving the alarm signal, the detection unit 121 decides whether to report it to the vehicle. In some embodiments, the detection unit 121 can decide whether to report to the vehicle according to the degree of change of the SOH and the potential impact on the vehicle. For example, when the relative change rate of the SOH is 2.5%, compared with a preset change rate of, for example, 2%, the SOH change is smaller and the impact on the vehicle is also smaller.

[0036] At this time, the detection unit 121 may not report to the vehicle. When the relative change rate of the SOH is 3%, compared with a preset change rate of, for example, 2%, the SOH change is larger and the impact on the vehicle is greater. At this time, the detection unit 121 will report to the vehicle. Additionally, the detection unit 121 can also decide whether to report to the vehicle according to the current operating state of the vehicle. For example, when the vehicle is performing an emergency operation, driving at a high speed or in other states that require priority handling, the detection unit 121 can choose to postpone reporting to the vehicle to avoid unnecessary interference to the driver.

[0037] In some embodiments, the processing module 120 may further include a storage unit 122, which can be used to store historical health state values and current health state values. Specifically, after obtaining the current health state value, the BMS 110 sends it to the detection unit 121, and the detection unit 121 sends the current health state value to the storage unit 122 for storage. The storage unit 122 then sends the stored historical health state values and current health state values to the detection unit 121 for the detection unit 121 to perform credibility detection. It can be understood that it is also feasible to store the SOH value in the detection unit 121. The detection unit 121 is mainly used for transmitting and calculating the SOH value, and its storage capacity is relatively limited. Therefore, it is preferably to set the storage unit 122 in the processing module 120, which can increase the data storage capacity of the processing module 120 and contribute to analyzing the long-term performance of the battery, formulating maintenance plans, predicting the battery life, etc.

[0038] In some embodiments, the storage unit 122 may be a telematics box (abbreviated as T-BOX). The T-BOX is usually combined with the vehicle's remote communication system, and the data stored in the T-BOX can be accessed through a remote connection, enabling the user to obtain the SOH value from a remote location and the data will not be lost when powering on and off. It can be understood that the storage unit 122 is not limited to this. For example, the storage unit 122 may also be a ferroelectric random access memory (FRAM), a flash memory, etc.

[0039] The method for calibrating the health state of a battery according to an embodiment of the present invention mainly includes the following steps.

[0040] Step S101: Obtain the current health state value of the battery.

[0041] Step S102: Perform credibility detection between the current health state value and the stored historical health state values.

[0042] Step S103: Based on the credibility detection result, change the current health state value to the historical health state value to calibrate the current health state value.

[0043] For the specific functions of the method for calibrating the health state of a battery according to this embodiment, reference can be made to the description in the foregoing Figure 1 embodiment, and details will not be repeated here.

[0044] The method for calibrating the health state of a battery according to another embodiment of the present invention may include the following steps.

[0045] Step S201: Obtain the current health status value of the battery.

[0046] Step S202: Detect the change rate of the current health status value relative to the historical health status value.

[0047] Step S203: Determine whether the relative change rate is greater than the preset change rate.

[0048] Step S204: When the relative change rate is greater than the preset change rate, send an alarm signal.

[0049] Step S205: After sending the alarm signal, change the current health status value to the historical health status value.

[0050] Step S206: When the relative change rate is less than or equal to the preset change rate, output the current health status value.

[0051] For the specific functions of the battery health status calibration method according to this embodiment, reference can be made to the description in the foregoing Figure 1 embodiment and will not be elaborated here.

[0052] The health status calibration system of the present invention uses the historical health status value and the current health status value to perform credibility detection to determine whether the current health status value is correct, and calibrates the current health status value by using the static SOH. Since the static SOH is the SOH of the battery in the static state and can be maintained continuously, the calibration accuracy of the SOH can be improved. Obtaining the static SOH does not require the battery to undergo a charge-discharge process. Compared with the calibration of the dynamic SOH (the SOH of the battery during actual operation), the static SOH calibration can be applied to various application scenarios, such as regularly checking the battery health status, etc. In addition, when the health status calibration system of the present invention detects that the current health status value is incorrect, it can quickly give an appropriate SOH value, improving the calibration speed of the SOH and ensuring that the battery can always have an appropriate SOH value.

[0053] It should be understood that the embodiments shown in the figures only show the optional configuration methods of the battery health status calibration system according to the present invention. However, they are only illustrative and not restrictive. Without departing from the spirit and scope of the present invention, other configuration methods can also be adopted.

[0054] The technical content and technical features of the present invention have been disclosed above. However, it can be understood that under the creative concept of the present invention, those skilled in the art can make various changes and improvements to the above-disclosed concept, but all belong to the protection scope of the present invention. The description of the above embodiments is illustrative rather than restrictive, and the protection scope of the present invention is determined by the claims.

Claims

1. A health state calibration system for a battery, characterized in that, The health state calibration system (100) includes: a battery management system (110) configured to obtain the current health state value of the battery; a processing module (120) configured to store historical health state values and perform credibility detection between the current health state value and the historical health state values, wherein the battery management system (110) is further configured to change the current health state value to the historical health state value based on the result of the credibility detection to calibrate the current health state value.

2. The health state calibration system of the battery according to claim 1, characterized in that, The processing module (120) includes a detection unit (121) configured to detect a change rate of the current health state value relative to the historical health state value and compare the change rate with a preset change rate.

3. The health state calibration system of the battery according to claim 2, wherein, The detection unit (121) is one of a vehicle controller, a body control module, and a DC-DC converter.

4. The health state calibration system of the battery according to claim 2, characterized in that, The battery management system (110) is configured to: change the current health state value to the historical health state value when the change rate is greater than the preset change rate, and output the current health state value when the change rate is less than or equal to the preset change rate.

5. The health state calibration system of the battery according to claim 4, wherein The battery management system (110) is further configured to: send an alarm signal to the detection unit (121) when the change rate is greater than the preset change rate.

6. The health state calibration system of the battery according to claim 2, characterized in that, The processing module (120) further includes a storage unit (122) configured to store the historical health state values and the current health state values.

7. The state-of-health calibration system for a battery according to claim 6, wherein The storage unit (122) is one of a telematics control unit, a ferroelectric random access memory, and a flash memory.

8. A method for calibrating the state of health of a battery, characterized in that, The health state calibration method includes: obtaining the current health state value of the battery (S101; S201); performing credibility detection between the current health state value and the stored historical health state values (S102); changing the current health state value to the historical health state value based on the result of the credibility detection to calibrate the current health state value (S103).

9. The method for calibrating the health state of the battery according to claim 8, characterized in that, Performing credibility detection between the current health state value and the stored historical health state values includes: detecting a change rate of the current health state value relative to the historical health state value (S202), and comparing the change rate with a preset change rate (S203).

10. The method for calibrating the state of health of a battery according to claim 9, wherein Changing the current health state value to the historical health state value based on the result of the credibility detection to calibrate the current state value includes: changing the current health state value to the historical health state value when the change rate is greater than the preset change rate (S205), and outputting the current health state value when the change rate is less than or equal to the preset change rate (S206).

11. The method for calibrating the state of health of the battery according to claim 10, characterized in that, Changing the current health state value to the historical health state value based on the result of the credibility detection to calibrate the current state value further includes: when the change rate is greater than the preset change rate, sending an alarm signal (S204).

12. A battery module, characterized in that, The battery module includes a plurality of batteries and a health state calibration system for the batteries according to any one of claims 1 to 7.

13. A vehicle, characterized in that, The vehicle includes a health state calibration system for the batteries according to any one of claims 1 to 7 or a battery module according to claim 12, or the vehicle uses a health state calibration method for the batteries according to any one of claims 8 to 11 to calibrate the health state of the vehicle's batteries.

Images