Automatic charging and discharging test item judgment and alarm strategy

Abstract

The invention relates to the field of new energy power battery pack detection systems, and mainly relates to an automatic charge and discharge test item judgment and alarm strategy, in the PACK offline detection process, whether a test detection item is qualified or not is automatically judged according to data, if the test item is unqualified, a device gives an alarm, and the unqualified item is displayed and transmitted to a channel display screen, so that the PACK offline detection process is finished. And the employees are powered off in time, analysis and processing are carried out according to detection items, PACK charging and discharging time is shortened, troubleshooting time of the employees is shortened, and the problems of the battery pack are rapidly processed.

Description

Technical Field

[0001] The present invention relates to the field of new energy power battery pack detection systems, and mainly relates to an automatic determination of charge and discharge test items and an alarm strategy. Background Art

[0002] With the vigorous development of the new energy industry, the testing of lithium batteries is of vital importance. Charge and discharge testing is an important means to ensure the performance, safety and reliability of battery packs. Charge and discharge testing can verify the actual capacity, energy, efficiency and other key performance parameters of the battery pack, ensuring that the battery can meet the design requirements in actual use.

[0003] For mass-produced battery packs, charge and discharge testing can verify battery consistency, ensuring that each battery's performance parameters are within a reasonable tolerance and preventing product quality issues. This is an essential step in battery R&D, production, and quality control. To meet these electrical testing requirements, pack factories require battery pack shipment inspection standards that include charging dynamic voltage difference, discharging dynamic voltage difference, discharge capacity, and discharge energy. However, in actual electrical testing, obtaining these values ​​requires essentially the completion of a full charge and discharge test. Electrical testers then review the data, identify unqualified test items, and identify potential problems. This undoubtedly increases the charge and discharge time of unqualified battery packs, increasing the time employees spend reviewing data and troubleshooting issues, thereby delaying pack production line production, saving electricity, and reducing charge and discharge energy consumption.

[0004] At present, an automatic determination of charge and discharge test items and an alarm strategy are proposed to solve the problems raised in the above background technology. Summary of the Invention

[0005] The purpose of the present invention is to provide an automatic judgment of charge and discharge test items and an alarm strategy, so as to solve the problem of automatically judging whether the test items are qualified according to the data during the offline detection of the PACK. If the test items fail, the equipment will alarm and transmit the unqualified items to the channel display screen. The staff will power off the system in time and analyze and process them according to the test items. At the same time, the charging and discharging time of the PACK is reduced, the time for employees to troubleshoot problems is reduced, and battery pack problems can be quickly handled.

[0006] An automatic determination of charge and discharge test items and alarm strategy, the specific steps are as follows: Step S10: The battery management system (BMS) is activated, and the device exchanges power-on instructions, starts powering on, and performs discharge, and then stands still after the discharge is completed. Step S20, fully charge, and after charging is completed, start self-test, read the dynamic voltage difference at the charging end and automatically calculate the charging voltage difference value △Ucharging, and determine whether △U≤250mv. If not, execute step S21, and if so, execute step S30; Step S21: Activate the warning light, automatically output the charging voltage difference value, determine it as unqualified, and shut down the power supply. The inspector will troubleshoot the problem based on the unqualified items. Step S30: Full discharge is performed. After the full discharge is completed, the system is allowed to stand for a while. The system starts a self-test, reads the dynamic voltage difference at the end of discharge, and automatically calculates the discharge voltage difference △U discharge. It is determined whether △U discharge ≤ 350mv. If the judgment is no, step S21 is executed. If so, step S40 is executed. Step S40, the system continues self-testing, reads the discharge capacity value, and determines whether the discharge capacity is greater than or equal to the system required capacity. If not, step S21 is executed; if so, step S50 is executed. In step S50, the system continues self-testing, reads the discharge energy value, and determines whether the discharge energy is greater than or equal to the system required capacity. If not, step S21 is executed; if so, step S60 is executed. In step S60, the system continues self-testing, reads the starting and ending temperature values ​​of the discharge process, and automatically calculates the temperature rise value ΔT rise during the discharge process, and determines whether ΔT rise is ≤ 20°C. If not, execute step S21; if so, execute step S70; In step S70, the system continues self-testing, reads the highest and lowest temperature values ​​during the discharge process, automatically calculates the temperature difference ΔT during the discharge process, and determines whether the ΔT difference is ≤ 10°C. If not, execute step S21; if so, execute step S80. Step S80, continue charging and let it stand after charging is completed; In step S90, the system starts self-test, reads the shipping SOC value, and determines whether the shipping SOC value is ≥60%. If not, execute step S21. If so, start the pass signal light, determine if it is qualified, execute power-off, and ship.

[0007] It is further defined that the alarm strategy also includes the division of alarm levels, and the alarm levels are divided into level one alarm, level two alarm and level three alarm, and the level one alarm, level two alarm and level three alarm correspond to warning signal lights of different colors respectively.

[0008] It is further defined that the temperature threshold of the battery cell is set at 60°C. When the temperature is greater than 60°C during charging and discharging, the first-level alarm state is entered, charging and discharging are immediately stopped, the warning signal light is activated, and on-site personnel are notified.

[0009] It is further specified that the battery cell will be stationary during charging and discharging, and the static voltage difference will be detected during the stationary process to see if it is greater than 10mv. If so, it indicates voltage imbalance, enters the second-level alarm state, activates the warning signal light, and notifies on-site personnel to conduct inspection.

[0010] Further limitation is to detect whether there is a dynamic charging voltage difference during the charging process, whether there is a dynamic discharge voltage difference during the discharge process, and if the cell voltage exceeds 3.65V during long-term charging and is lower than 2.5V during discharge, capacity decay may occur. Perform cell capacity detection. When it is detected that the cell capacity is lower than the set value, enter the third-level alarm state, start the warning signal light, and notify on-site personnel to check, record and report.

[0011] The beneficial effects of the present invention compared to the current technology are: The system automatically determines whether test items are qualified based on data. If a test item fails, the device issues an alarm and transmits the failed item to the channel display screen. Employees can then promptly power off the system and analyze and process the test items accordingly. This reduces the charge and discharge time of the pack, reduces the time employees spend troubleshooting problems, and allows for quick resolution of battery pack issues. This system also saves energy, reduces charging and discharging energy consumption, and saves employees time reviewing data and identifying problem points, thus reducing production line capacity delays, energy consumption, and costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 Schematic diagram of logic control of the present invention DETAILED DESCRIPTION

[0013] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments. Example

[0014] like Figure 1 As shown, an automatic judgment of charge and discharge test items and alarm strategies requires detection of charging dynamic voltage difference, discharging dynamic voltage difference, discharge capacity, discharge energy, temperature rise during discharge, temperature difference during discharge, and shipping SOC.

[0015] A large voltage difference at the end of charge may indicate inconsistent capacity or internal resistance between cells in the battery pack. This inconsistency may cause some cells to reach the cutoff voltage prematurely during charging, preventing the full utilization of the capacity of other cells, reducing their charge and discharge efficiency and maximum available capacity. A sustained large voltage difference may exacerbate the imbalance within the battery pack, thereby shortening the service life of the entire battery pack. A large voltage difference may also cause the battery to overcharge or over-discharge, posing a safety hazard. A large voltage difference may affect the overall performance of the battery pack, including reducing its charge and discharge efficiency and maximum available capacity. By controlling the voltage difference at the end of charge during charge and discharge tests, potential problems can be discovered and resolved in a timely manner, ensuring the safe, stable and efficient operation of the battery pack. The voltage difference at the end of discharge can reflect the consistency of the individual cells in the battery pack. A large voltage difference may indicate that some cells have experienced capacity decay or increased internal resistance, reflecting the battery health. A large voltage difference may cause the battery pack to overheat, damage, or even safety hazards during use. By controlling the voltage difference, these problems can be discovered and addressed in a timely manner to ensure the safe operation of the battery pack. Through charge and discharge tests, we can understand the capacity released by the battery in actual use. If the discharge capacity is lower than expected, it means that the battery cannot meet the performance requirements of the system; if the discharge energy is lower than expected, it means that the battery cannot meet the performance requirements of the system; The temperature rise during discharge is an important test item in charge and discharge tests. Batteries generate heat during discharge. If too much heat accumulates and cannot be effectively dissipated, the battery temperature may become too high. Excessive temperature not only affects battery performance, but may also cause irreversible changes in the battery's internal materials or structure, leading to safety hazards such as fire or explosion. Temperature rise data helps evaluate battery performance. Temperature changes can have a significant impact on battery performance. Both excessively high and low temperatures can seriously affect battery performance and even affect the safe use of the battery. By monitoring temperature rise, the discharge characteristics of the battery can be more accurately evaluated. Temperature differences can affect the battery's charge and discharge efficiency and capacity, leading to inconsistent performance between batteries in the same group. By managing temperature differences, the overall performance and stability of the battery pack can be improved. Larger temperature differences may accelerate the battery's aging process and shorten its service life. It takes a certain amount of time for the battery pack to be loaded onto the vehicle at the vehicle manufacturer, and the time period is uncertain. The battery will consume energy during this process, so the PACK factory controls and manages it according to the SOC standard of the vehicle's shipment.

[0016] The specific detection steps are as follows: Step S10: The battery management system (BMS) is activated, and the device exchanges power-on instructions, starts powering on, and performs discharge, and then stands still after the discharge is completed. Step S20: Full charge is performed. After charging is completed, a self-test is started to read the dynamic voltage difference at the charging end (i.e., the highest cell voltage and the lowest cell voltage) and automatically calculate the charging voltage difference value △Ucharging. It is determined whether △U≤250mv. If not, step S21 is executed. If so, step S30 is executed. Step S21: Activate the warning light, automatically output the charging voltage difference value, determine it as unqualified, and shut down the power supply. The inspector will troubleshoot the problem based on the unqualified items. Step S30: Full discharge is performed. After the full discharge is completed, the system is allowed to stand for a while. The system starts a self-test, reads the dynamic voltage difference at the end of discharge, and automatically calculates the discharge voltage difference △U discharge. It is determined whether △U discharge ≤ 350mv. If the judgment is no, step S21 is executed. If so, step S40 is executed. Step S40, the system continues self-testing, reads the discharge capacity value, and determines whether the discharge capacity is greater than or equal to the system required capacity. If not, step S21 is executed; if so, step S50 is executed. In step S50, the system continues self-testing, reads the discharge energy value, and determines whether the discharge energy is greater than or equal to the system required capacity. If not, step S21 is executed; if so, step S60 is executed. In step S60, the system continues self-testing, reads the starting and ending temperature values ​​of the discharge process, and automatically calculates the temperature rise value ΔT rise during the discharge process, and determines whether ΔT rise is ≤ 20°C. If not, execute step S21; if so, execute step S70; In step S70, the system continues self-testing, reads the highest and lowest temperature values ​​during the discharge process, automatically calculates the temperature difference ΔT during the discharge process, and determines whether the ΔT difference is ≤ 10°C. If not, execute step S21; if so, execute step S80. Step S80, continue charging and let it stand after charging is completed; In step S90, the system starts self-test, reads the shipping SOC value, and determines whether the shipping SOC value is ≥60%. If not, execute step S21. If so, start the pass signal light, determine if it is qualified, execute power-off, and ship.

[0017] The alarm strategy also includes the division of alarm levels, which are divided into level one, level two and level three. Level one, level two and level three alarms correspond to warning lights of different colors respectively. The temperature threshold of the battery cell is set to 60°C. When the temperature is greater than 60°C during charging and discharging, the level one alarm state is entered, charging and discharging are stopped immediately, the warning light is activated, and on-site personnel are notified. The battery cell will be stationary during charging and discharging. During the stationary process, the static voltage difference is detected to see if it is greater than 10mv. If so, it indicates voltage imbalance, the level two alarm state is entered, the warning light is activated, and on-site personnel are notified to check whether there is a charging dynamic voltage difference during charging and whether there is a discharging dynamic voltage difference during discharging. If the battery cell exceeds 3.65V during long-term charging and is lower than 2.5V during discharging, capacity decay may occur. The single cell capacity of the battery cell is detected. When it is detected that the single cell capacity of the battery cell is lower than the set value, the level three alarm state is entered, the warning light is activated, and on-site personnel are notified to check, record and report.

[0018] The above is a detailed introduction to an automatic judgment of charge and discharge test items and alarm strategies provided by the present invention. The description of the specific embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. An automatic determination of charge and discharge test items and alarm strategy, characterized by: The specific steps are as follows: Step S10: The battery management system (BMS) is activated, and the device exchanges power-on instructions, starts powering on, and performs discharge, and then stands still after the discharge is completed. Step S20, fully charge, and after charging is completed, start self-test, read the dynamic voltage difference at the charging end and automatically calculate the charging voltage difference value △Ucharging, and determine whether △U≤250mv. If not, execute step S21, and if so, execute step S30; Step S21: Activate the warning light, automatically output the charging voltage difference value, determine it as unqualified, and shut down the power supply. The inspector will troubleshoot the problem based on the unqualified items. Step S30: Full discharge is performed. After the full discharge is completed, the system is allowed to stand for a while. The system starts a self-test, reads the dynamic voltage difference at the end of discharge, and automatically calculates the discharge voltage difference △U discharge. It is determined whether △U discharge ≤ 350mv. If the judgment is no, step S21 is executed. If so, step S40 is executed. Step S40, the system continues self-testing, reads the discharge capacity value, and determines whether the discharge capacity is greater than or equal to the system required capacity. If not, step S21 is executed; if so, step S50 is executed. In step S50, the system continues self-testing, reads the discharge energy value, and determines whether the discharge energy is greater than or equal to the system required capacity. If not, step S21 is executed; if so, step S60 is executed. In step S60, the system continues self-testing, reads the starting and ending temperature values ​​of the discharge process, and automatically calculates the temperature rise value ΔT rise during the discharge process, and determines whether ΔT rise is ≤ 20°C. If not, execute step S21; if so, execute step S70; In step S70, the system continues self-testing, reads the highest and lowest temperature values ​​during the discharge process, automatically calculates the temperature difference ΔT during the discharge process, and determines whether the ΔT difference is ≤ 10°C. If not, execute step S21; if so, execute step S80. Step S80, continue charging and let it stand after charging is completed; In step S90, the system starts self-test, reads the shipping SOC value, and determines whether the shipping SOC value is ≥60%. If not, execute step S21. If so, start the pass signal light, determine if it is qualified, execute power-off, and ship.

2. The automatic determination of charge and discharge test items and alarm strategy according to claim 1, characterized in that: The alarm strategy also includes the classification of alarm levels. The alarm levels are divided into level one alarm, level two alarm and level three alarm. The level one alarm, level two alarm and level three alarm correspond to warning lights of different colors respectively.

3. The automatic determination of charge and discharge test items and alarm strategy according to claim 2, characterized in that: The temperature threshold of the battery cell is set to 60°C. When the temperature exceeds 60°C during charging and discharging, the system enters a level 1 alarm state, immediately stops charging and discharging, activates the warning light, and notifies on-site personnel.

4. The automatic determination of charge and discharge test items and alarm strategy according to claim 2, characterized in that: The battery cell will be kept at rest during charging and discharging. During the resting process, the static voltage difference is detected to see if it is greater than 10mv. If so, it indicates voltage imbalance, and the battery enters the secondary alarm state, activates the warning signal light, and notifies on-site personnel to conduct an inspection.

5. The automatic determination of charge and discharge test items and alarm strategy according to claim 2, characterized in that : Detect whether there is a dynamic charging voltage difference during the charging process, and whether there is a dynamic discharge voltage difference during the discharging process. If the battery cell exceeds 3.65V during long-term charging and the battery cell is lower than 2.5V during discharge, capacity decay may occur. Perform single cell capacity detection on the battery cell. When it is detected that the single cell capacity of the battery cell is lower than the set value, it enters the third-level alarm state, starts the warning signal light, and notifies the on-site personnel to check, record and report.

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