Power battery bridging copper bar voltage sampling compensation method and device, electronic equipment and storage medium

Abstract

The invention discloses a power battery bridging copper bar voltage sampling compensation method and device, electronic equipment and a storage medium. The bridging copper bar voltage sampling compensation method comprises the steps that in the battery operation process, the temperature of a bridging copper bar and the real-time current flowing through the bridging copper bar are obtained in real time; the resistance value and the real-time current of the bridging copper bar at the corresponding temperature are found according to a preset target temperature-resistance curve, and the partial voltage of the copper bar is calculated; and deducting the copper bar partial voltage from the battery voltage acquired in real time, and compensating and calculating the real voltage of the battery. According to the invention, no hardware sampling channel is added, the problem of inaccurate voltage acquisition caused by bridging copper bar resistance voltage division can be effectively solved, the cost is reduced, and the system reliability is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electric batteries, and particularly to a method and device for compensating the voltage sampling of a power battery cross-connecting copper bar, an electronic device, and a storage medium. Background Art

[0002] In recent years, the design trend of battery packs has been to increase the energy density and save costs. In such a trend, it is necessary to reasonably design the arrangement and spacing of battery cells, adopt a more compact stacking structure or a new type of battery cell packaging form, and accommodate more battery cells in the same space, so as to improve the energy density of the energy storage pack and reduce the cost per unit of energy. In the electrical connection of batteries inside the module, in order to prevent the voltage difference between the sampling terminals from being too large or when the physical arrangement of the batteries is restricted by factors such as space and shape, it is difficult to avoid using cross-connecting copper bars for electrical connection, which will introduce cross-connecting copper bar connections. The cross-connecting copper bar will cause voltage changes during the charging and discharging process of the battery. The use of the cross-connecting copper bar will introduce the problem of resistance voltage division of the cross-connecting copper bar into the original voltage acquisition, resulting in inaccurate acquisition voltage, that is, the voltage acquisition is inaccurate.

[0003] Traditional methods for compensating the voltage of the cross-connecting copper bar often rely on increasing the hardware sampling channels to directly measure the voltage drop on the copper bar and then perform compensation. This method is not only limited by the hardware cost and complexity, but also cannot be implemented in some application scenarios with limited space or extremely sensitive to cost, and the voltage division caused by the contact resistance of the copper bar still cannot be eliminated. In many electrical systems and battery management systems, the number of hardware sampling channels is usually limited. Increasing the hardware sampling channels means higher costs, more complex circuit board designs, and possibly larger device volumes. For example, in the monitoring of battery packs, adding each hardware sampling channel requires adding corresponding analog-to-digital conversion (ADC) circuits, signal conditioning circuits, etc., which not only increases the hardware cost, but also occupies more printed circuit board (PCB) space. Moreover, the increase in hardware channels may introduce more interference sources and reduce the reliability of the system. Because more circuit components mean more electromagnetic interference (EMI) generation points and interference-affected points, making it more difficult for the system to ensure the accuracy of signal acquisition in a complex electromagnetic environment.

[0004] Chinese Patent CN110884389A discloses a sampling compensation method. By reading the calibration parameters of the copper busbar, the current value of the current sensor is obtained, the temperature of the copper busbar and the compensation voltage are calculated, and the compensation voltage generated by the copper busbar is calculated using the formula Ut = IR1 + I[R2 + R2(T - 20)*k and added to the cell voltage to obtain the actual voltage. The method is complex and difficult to operate in practice. Chinese Patent CN1108843891 discloses a compensation method. By reading the calibration parameters of the copper busbar, the current value of the current sensor is obtained, the temperature and resistance value of the copper busbar are calculated, the copper busbar voltage is calculated using the compensation formula, and added to the cell voltage. The compensation algorithm is simple and single, and the accuracy is low. Summary of the Invention

[0005] The object of the present invention is to overcome the problems in the prior art that the method of adding a hardware sampling channel to compensate for the voltage of the cross-connected copper busbar cannot eliminate the influence of contact resistance, increase costs and hardware complexity, and provide a method and device for sampling and compensating the voltage of the cross-connected copper busbar of a power battery, an electronic device and a storage medium. The present invention does not increase the hardware sampling channel, can effectively solve the problem of inaccurate voltage acquisition caused by the resistance voltage division of the cross-connected copper busbar, reduce costs, and improve the reliability of the system.

[0006] In the first aspect of the present invention, a method for sampling and compensating the voltage of a cross-connected copper busbar of a power battery is provided, including the steps of:

[0007] During the operation of the battery, the temperature of the cross-connected copper busbar and the real-time current flowing through the cross-connected copper busbar are obtained in real time;

[0008] According to the preset target temperature-resistance curve, the resistance value of the cross-connected copper busbar at the corresponding temperature and the real-time current are found, and the copper busbar voltage division is calculated;

[0009] The copper busbar voltage division is deducted from the battery voltage collected in real time, and the true voltage of the battery is calculated by compensation.

[0010] Among them, the target temperature-resistance curve is obtained by data fusion and correction of the static temperature-resistance curve of the cross-connected copper busbar and the dynamic temperature-resistance curve obtained by using the battery charge and discharge data.

[0011] Among them, the formation of the static temperature-resistance curve of the cross-connected copper busbar includes the steps of:

[0012] Consult the standard cross-connected copper busbar temperature-resistivity table to obtain the resistivity ρ of the cross-connected copper busbar at different temperatures;

[0013] According to the resistance calculation formula R = ρ*L / S, the theoretical resistance value of the cross-connected copper busbar at different temperatures is calculated;

[0014] Taking the temperature as the independent variable and the theoretical resistance value as the dependent variable, a static temperature-resistance curve is drawn;

[0015] In the formula, L is the length of the jumper copper bar, and S is the cross-sectional area of the jumper copper bar.

[0016] Among them, the dynamic temperature-resistance curve of the jumper copper bar is formed by calibrating the voltage change during the dynamic charging process, and includes the steps of:

[0017] Recording the partial voltage data and current of the jumper copper bar during the charging and discharging process of the battery at a set time interval;

[0018] Obtaining the dynamic resistance of the jumper copper bar according to the partial voltage data and current of the jumper copper bar;

[0019] According to the dynamic resistance of the jumper copper bar and the data of the corresponding temperature monitored during the charging and discharging process of the battery, using the fitting algorithm to obtain the dynamic temperature-resistance curve of the jumper copper bar under dynamic charging and discharging of the battery.

[0020] Among them, the dynamic resistance of the jumper copper bar during the charging and discharging process of the battery includes the average value of multiple resistance values obtained by measuring the partial voltage data and current of the jumper copper bar under different working conditions multiple times.

[0021] Among them, the partial voltage data and current of the jumper copper bar during the charging and discharging process of the battery are obtained by arranging high-precision voltage sensors and high-precision current sensors at preset positions to obtain voltage and current data.

[0022] In the second aspect of the present invention, a voltage sampling compensation device for the jumper copper bar of a power battery system is provided, including:

[0023] A data acquisition module for real-time acquiring the temperature of the jumper copper bar and the real-time current flowing through the jumper copper bar during the operation of the battery;

[0024] A calculation module for calculating the partial voltage of the copper bar according to the resistance value and real-time current of the jumper copper bar at the corresponding temperature found from the preset target temperature-resistance curve;

[0025] A determination module for deducting the partial voltage of the copper bar from the real-time collected battery voltage to compensate and calculate the true voltage of the battery.

[0026] In the third aspect of the present invention, an electronic device is provided, including one or more processors and a memory, where the memory is used to store one or more programs, and when the one or more programs are executed by the one or more processors, the one or more processors perform the voltage sampling compensation method for the jumper copper bar of the power battery system.

[0027] In a fourth aspect of the present invention, there is provided a computer-readable storage medium having a readable computer program stored thereon, and when the program is executed by a processor, the method for compensating the voltage sampling of the jumper busbar of the power battery system is implemented.

[0028] In a fifth aspect of the present invention, there is provided a computer program product containing instructions, and when the computer program product runs on a computer, the computer is caused to execute the method for compensating the voltage sampling of the jumper busbar of the power battery system.

[0029] In the present invention, during the operation of the battery, after the temperature of the jumper busbar and the real-time current flowing through the jumper busbar are obtained in real time, the resistance value of the jumper busbar at the corresponding temperature and the real-time current are found according to the preset target temperature-resistance curve, the voltage division of the busbar is calculated, and then the software algorithm is used to deduct the voltage division of the busbar from the battery voltage collected in real time to compensate and calculate the real voltage of the battery; it can effectively eliminate the voltage division to compensate and calculate the real voltage, can effectively solve technical problems such as inaccurate voltage acquisition caused by the resistance voltage division of the jumper busbar, and at the same time can reduce costs and improve system reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a flowchart of the method for compensating the voltage sampling of the jumper busbar of the power battery in an embodiment of the present invention.

[0031] Figure 2 is a schematic diagram of the voltage division principle of the jumper busbar of the power battery given in an embodiment of the present invention.

[0032] Figure 3 is a schematic diagram of the voltage acquisition of 48S battery cells given in an embodiment of the present invention.

[0033] Figure 4 is a flowchart of the formation of the static temperature-resistance curve of the jumper busbar given in an embodiment of the present invention.

[0034] Figure 5 is a flowchart of the formation of the dynamic temperature-resistance curve of the jumper busbar given in an embodiment of the present invention.

[0035] Figure 6 is a schematic diagram of the principle of the device for compensating the voltage sampling of the jumper busbar of the power battery given in an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0037] See Figure 1As shown in the figure, an embodiment of the present application provides a method for compensating the voltage sampling of a bridging copper busbar of a power battery system, which includes the following steps:

[0038] During the operation of the battery, the temperature of the bridging copper busbar and the real-time current flowing through the bridging copper busbar are obtained in real time; according to the preset target temperature-resistance curve, the resistance value of the bridging copper busbar at the corresponding temperature and the real-time current are found, and the copper busbar voltage division is calculated; the copper busbar voltage division is deducted from the battery voltage collected in real time to compensate and calculate the real voltage of the battery.

[0039] In the embodiment of the present application, the voltage division principle of the bridging copper busbar is as Figure 2 shown. The battery charge and discharge current is I 大 , which is the current flowing through the bridging copper busbar. The discharge current of the NTC detection circuit is I 小 , the resistance of the bridging copper busbar is R 铜排 , and the NTC resistance is R NTC . In the embodiment of the present application, the voltage acquisition points of the 48S battery cells are distributed as Figure 1 shown. The voltages of 48 battery cells are sampled through 49 sampling points, including two bridging copper busbars. As shown in Figure 3 R_BUS1 and R_BUS2, the three modules are bridged. The voltage of the first cell on the left is obtained from V1 - V0, and so on. Calculate the voltage of the 12th cell connected to the bridging copper busbar, E12 = U 采 +U 铜排 =R NTC *I 小 +R 铜排 *I 大 . Since the internal resistance of the battery cell and the resistance of the sampling wire are negligible, during charging and discharging, the real voltage of the battery = U 采 +R 铜排 *I 大 . The battery charge and discharge current I 大 is obtained by a current sensor. Due to the existence of contact resistance and the large influence of resistance on temperature change, in this application, by statically calculating the resistance of the bridging copper busbar and dynamically collecting data to correct the temperature-resistance curve, the resistance R 铜排 of the bridging copper busbar can be continuously reduced, and finally a more accurate calculation of the resistance R 铜排 is achieved, so that when calculating the copper busbar voltage division through the curve to find the resistance R 铜排 , it is more precise or accurate, thus ensuring that the real voltage of the battery calculated by compensation is more in line with the actual situation or more accurate. 铜排

[0040] In the embodiment of the present application, the preset target temperature-resistance curve is obtained through data processing in advance and can be stored in the memory of the battery management system or a similar system for query and use.

[0041] Exemplarily, the temperature of the jumper busbar is obtained by a temperature sensor, the real-time current flowing through the jumper busbar is obtained by a high-precision current sensor, the resistance value of the jumper busbar at the corresponding temperature is obtained by looking up a table, and then the voltage division of the jumper busbar, i.e., the busbar voltage division, can be calculated based on the resistance value obtained by looking up the table and the measured real-time current. Then, by using a software algorithm and a preset program to subtract the calculated busbar voltage division from the collected voltage, the true voltage of the battery can be calculated.

[0042] In the embodiment of the present invention, by using the target temperature-resistance curve to find the temperature value, calculating the busbar voltage division according to the found temperature value and the real-time current, and eliminating the busbar voltage division through a software algorithm, the true voltage is compensated and calculated, effectively solving the problem of inaccurate voltage acquisition caused by the resistance voltage division of the jumper busbar, reducing costs, and improving the reliability of the system.

[0043] In an exemplary embodiment, the target temperature-resistance curve is obtained by data fusion and correction of the static temperature-resistance curve of the jumper busbar and the dynamic temperature-resistance curve obtained by using battery charge and discharge data.

[0044] Exemplarily, when fusing the data of the static temperature-resistance curve and the dynamic temperature-resistance curve obtained during the dynamic charge and discharge process, the two sets of data are merged into a dataset, and the data is sorted and preprocessed to ensure the consistency and accuracy of the data. Finally, the two curves are fitted into a new temperature-resistance curve by the least squares method. By minimizing the sum of the squares of the errors between the actual data points and the fitted curve through the least squares method, a curve that best represents the data trend can be obtained, effectively reducing the experimental error.

[0045] See Figure 4 As shown, in an exemplary embodiment, the formation of the static temperature-resistance curve of the jumper busbar includes the steps of: consulting a standard temperature-resistivity table of the jumper busbar to obtain the resistivity ρ of the jumper busbar at different temperatures; calculating the theoretical resistance value of the jumper busbar at different temperatures according to the resistance calculation formula R = ρ * L / S; taking the temperature as the independent variable and the theoretical resistance value as the dependent variable, and plotting the static temperature-resistance curve; where L is the length of the jumper busbar and S is the cross-sectional area of the jumper busbar.

[0046] See Figure 5As shown, in an exemplary embodiment, the dynamic temperature-resistance curve of the jumper busbar is formed by calibrating the voltage change during the dynamic charging process, including the steps of: recording the voltage division data and current of the jumper busbar during the battery charge and discharge process at a set time interval; obtaining the dynamic resistance of the jumper busbar according to the voltage division data and current of the jumper busbar; and obtaining the dynamic temperature-resistance curve of the jumper busbar under the dynamic battery charge and discharge using a fitting algorithm based on the dynamic resistance of the jumper busbar and the corresponding temperature data monitored during the battery charge and discharge process.

[0047] Exemplarily, the dynamic resistance of the jumper busbar during the battery charge and discharge process may also be the average value of multiple resistance values obtained by measuring the voltage division data and current of the jumper busbar under different working conditions multiple times, that is, the average value of multiple resistance values measured multiple times is used as the dynamic resistance of the jumper busbar for the final calculation. Based on this, the dynamic temperature-resistance curve of the jumper busbar under the dynamic battery charge and discharge is finally plotted.

[0048] Exemplarily, the fitting algorithm may be a polynomial fitting algorithm for curve fitting. For example, a suitable second-order or third-order polynomial is selected, and through mathematical calculations, a polynomial function that can best fit the data is obtained, resulting in a polynomial curve with temperature as the abscissa and resistance as the ordinate, which can accurately describe the relationship between the two through fitting. This polynomial curve is the dynamic temperature-resistance curve of the jumper busbar under the dynamic battery charge and discharge, reflecting the corresponding resistance values of the jumper busbar at different temperatures during the charge and discharge process.

[0049] Exemplarily, the voltage division data and current of the jumper busbar during the battery charge and discharge process are obtained by arranging high-precision voltage sensors and high-precision current sensors at preset positions to obtain voltage and current data. Specifically, the voltage division data of the jumper busbar during the battery charge and discharge process is obtained by calculating the difference after obtaining the voltage of the jumper busbar voltage point and its nearby points through high-precision voltage sensors arranged at both ends of the jumper busbar and at the battery cell connection points close to the jumper busbar, that is, by collecting the actual voltage - U 采 =U 铜排 during the battery charge and discharge, and thus obtaining the voltage division data of the jumper busbar.

[0050] See Figure 6As shown, in an embodiment of the present application, a voltage sampling compensation device for a power battery cross-connecting copper bar is further provided, including: a data acquisition module for real-time acquiring the temperature of the cross-connecting copper bar and the real-time current flowing through the cross-connecting copper bar during the operation of the battery; a calculation module for looking up the resistance value of the cross-connecting copper bar at the corresponding temperature and the real-time current according to a preset target temperature-resistance curve, and calculating the copper bar voltage division; a determination module for deducting the copper bar voltage division from the battery voltage collected in real time to compensate and calculate the true voltage of the battery.

[0051] In an embodiment of the present application, an electronic device is further provided, including one or more processors and a memory, where the memory is used to store one or more programs. Among them, when the one or more programs are executed by the one or more processors, the one or more processors implement the cross-connecting copper bar voltage sampling compensation method of the power battery system. Specifically, for the technical content of the cross-connecting copper bar voltage sampling compensation method of the power battery system, please refer to the content of the embodiments of the cross-connecting copper bar voltage sampling compensation method of the power battery system in the present application.

[0052] In an embodiment of the present application, a computer-readable storage medium is further provided, on which a readable computer program is stored. When the program is executed by a processor, it implements the cross-connecting copper bar voltage sampling compensation method of the power battery system. Specifically, for the technical content of the cross-connecting copper bar voltage sampling compensation method of the power battery system, please refer to the content of the embodiments of the cross-connecting copper bar voltage sampling compensation method of the power battery system in the present application.

[0053] In an embodiment of the present application, a computer program product containing instructions is further provided. When the computer program product runs on a computer, the computer is enabled to execute the cross-connecting copper bar voltage sampling compensation method of the power battery system. Specifically, for the technical content of the cross-connecting copper bar voltage sampling compensation method of the power battery system, please refer to the content of the embodiments of the cross-connecting copper bar voltage sampling compensation method of the power battery system in the present application.

[0054] The foregoing has shown and described the basic principles, main features and advantages of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms.

[0055] Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, it is intended to embrace all changes falling within the meaning and scope of the equivalent elements of the claims in the present invention.

[0056] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment contains only an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for sampling and compensating voltage of a power battery cross-connect copper bar, characterized in that: Contains steps: During the battery operation, the temperature of the copper busbar and the current flowing through the copper busbar are obtained in real time; According to the preset target temperature-resistance curve, the resistance value of the cross-connected copper busbar at the corresponding temperature and the real-time current are found, and the partial pressure of the copper busbar is calculated; The copper bar voltage is deducted from the real-time collected battery voltage, and the actual battery voltage is calculated through compensation.

2. The method for sampling and compensating voltage of a power battery cross-connect copper bar according to claim 1 is characterized in that: The target temperature-resistance curve is obtained by fusing and correcting the static temperature-resistance curve of the cross-connected copper busbar and the dynamic temperature-resistance curve obtained by using the battery charging and discharging data.

3. The method for sampling and compensating voltage of a power battery cross-connect copper bar according to claim 2 is characterized in that: The formation of the static temperature-resistance curve of the jumper copper busbar comprises the following steps: Refer to the standard temperature-resistivity table of the cross-connect copper busbar to obtain the resistivity ρ of the cross-connect copper busbar at different temperatures; According to the resistance calculation formula R = ρ * L / S, calculate the theoretical resistance value of the cross-connected copper busbar at different temperatures; Taking the temperature as the independent variable and the theoretical resistance value as the dependent variable, a static temperature-resistance curve is drawn; Where, L is the length of the jumper copper bar, and S is the cross-sectional area of ​​the jumper copper bar.

4. The method for sampling and compensating voltage of a power battery cross-connect copper bar according to claim 2 is characterized in that: The dynamic temperature-resistance curve of the cross-connected copper busbar is formed by calibrating the voltage change during the dynamic charging process, including the steps of: Record the voltage division data and current of the copper busbar during battery charging and discharging at set time intervals; According to the voltage division data and current of the cross-connected copper busbar, a dynamic resistance of the cross-connected copper busbar is obtained; According to the dynamic resistance of the cross-connected copper busbar and the corresponding temperature data monitored during the battery charging and discharging process, a dynamic temperature-resistance curve of the cross-connected copper busbar under the dynamic charging and discharging of the battery is obtained by using a fitting algorithm.

5. The method for sampling and compensating voltage of a power battery cross-connect copper bar according to claim 4 is characterized in that: The dynamic resistance of the copper busbar during the battery charging and discharging process includes an average value of multiple resistance values ​​obtained by repeatedly measuring the voltage division data and current of the copper busbar under different working conditions.

6. The method for sampling and compensating voltage of a power battery cross-connect copper bar according to claim 4 is characterized in that: The voltage division data and current of the copper busbar connected across the battery during the charging and discharging process are obtained by arranging a high-precision voltage sensor and a high-precision current sensor at a preset position to obtain voltage and current data.

7. The voltage sampling and compensation device for the power battery cross-connect copper bar is characterized by: include: The data acquisition module is used to obtain the temperature of the jumper copper bar and the real-time current flowing through the jumper copper bar in real time during the operation of the battery; The calculation module is used to find the resistance value of the cross-connected copper busbar at the corresponding temperature and the real-time current according to the preset target temperature-resistance curve, and calculate the partial pressure of the copper busbar; The determination module is used to deduct the copper bar voltage from the real-time collected battery voltage and compensate to calculate the real voltage of the battery.

8. An electronic device, characterized in that It comprises one or more processors and a memory, wherein the memory is used to store one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the power battery cross-copper busbar voltage sampling and compensation method as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that A readable computer program is stored thereon, and when the program is executed by a processor, the method for sampling and compensating the voltage of the power battery cross-connect copper bar as described in any one of claims 1 to 6 is implemented.

10. A computer program product comprising instructions, characterized in that When the computer program product is run on a computer, the computer is enabled to execute the method for sampling and compensating the voltage of the power battery cross-connect copper bar as described in any one of claims 1 to 6.

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