Energy balancing method, apparatus, device, and storage medium

Abstract

This invention discloses an energy balancing method, apparatus, device, and storage medium. The energy balancing method includes: acquiring the individual cell voltage of a battery cell after it has been left to stand for a preset time to obtain individual cell voltage data; if the individual cell voltage data is equal to or higher than a preset individual cell voltage threshold, performing differential calculation on the individual cell voltage data to obtain differential voltage data; searching for inflection points in the differential voltage data according to a pre-constructed relational value table to obtain characteristic inflection points; acquiring the battery cell's charge based on the characteristic inflection points to obtain characteristic charge; acquiring the battery's health status value to obtain battery health status value; performing balancing calculations based on the characteristic charge, battery health status value, and preset standard capacity to obtain balanced charge; and performing energy balancing on the battery based on the balanced charge. This invention can improve the accuracy of the acquired balanced charge, thereby improving the accuracy of energy balancing of the battery.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to an energy balancing method, apparatus, device, and storage medium. Background Technology

[0002] Currently, vehicle-mounted BMS employs a method for diagnosing (balancing) the consistency of individual battery cells, determining the balancing amount of each cell based on the voltage difference at the charging end. However, because the internal resistance of battery cells increases with aging, and the increase in internal resistance varies among cells, determining the balancing amount based on voltage differences can lead to significant errors. Therefore, reducing the error in balancing amount is a pressing issue that needs to be addressed. Summary of the Invention

[0003] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes an energy balancing method that can improve the accuracy of the obtained balanced charge, thereby improving the accuracy of energy balancing in power supply batteries.

[0004] The present invention also proposes an energy balancing device.

[0005] The present invention also proposes an energy balancing device.

[0006] The present invention also proposes a computer-readable storage medium.

[0007] In a first aspect, one embodiment of the present invention provides an energy balancing method applied to a vehicle's power supply battery, comprising:

[0008] The individual cell voltage of the battery cell is obtained to obtain individual cell voltage data; wherein, the individual cell voltage is the voltage of the battery after it has been fully charged and left to stand for a preset time before being discharged.

[0009] If the individual cell voltage data is equal to or higher than a preset individual cell voltage threshold, the individual cell voltage data is differentiated to obtain differential voltage data;

[0010] The differential voltage data is searched for inflection points according to a pre-constructed relational value table to obtain characteristic inflection points; wherein, the relational value table is constructed based on the pairing data of the differential voltage data and time.

[0011] The power level of the battery cell is obtained based on the characteristic inflection point to obtain the characteristic power level;

[0012] Obtain the health status value of the power supply battery to obtain the battery health status value;

[0013] The balanced power is obtained by performing a balanced calculation based on the characteristic power level, the battery health status value, and the preset standard capacity.

[0014] The power supply battery is equilibrated based on the balanced charge level.

[0015] The energy balancing method of this invention has at least the following beneficial effects: When a battery cell is left to stand still for a preset time, the battery cell is in a static state. The cell voltage of the battery cell in the static state is obtained to obtain cell voltage data. The cell voltage data is compared with a preset cell voltage threshold. If the cell voltage data is equal to or higher than the preset cell voltage threshold, the cell voltage data is differentiated to obtain differential voltage data. A relationship value table is constructed based on the pairing data of differential voltage data and time. The inflection point of the differential voltage data is searched according to the relationship value table to obtain the characteristic inflection point. The cell charge value at the characteristic inflection point is obtained to obtain the characteristic charge value. The battery health status value is obtained to obtain the battery health status value. The balancing calculation is performed based on the characteristic charge value, the battery health status value, and the preset standard capacity to obtain the balanced charge value. Energy balancing of the battery is performed based on the balanced charge value, which can improve the accuracy of the obtained balanced charge value, thereby improving the accuracy of energy balancing of the battery.

[0016] According to other embodiments of the energy balancing method of the present invention, the differential voltage data includes first-order voltage data and second-order voltage data, and the differential calculation of the individual voltage data to obtain the differential voltage data includes:

[0017] The individual voltage data is differentiated to obtain the first-order voltage data;

[0018] The first-order voltage data is differentiated to obtain the second-order voltage data.

[0019] According to other embodiments of the energy balancing method of the present invention, the relational value table includes a first-order relational value table and a second-order relational value table. The first-order relational value table is constructed based on the paired data of the first-order voltage data and time, and the second-order relational value table is constructed based on the paired data of the second-order voltage data and time. The step of searching for inflection points in the differential voltage data according to the preset relational value table to obtain characteristic inflection points includes:

[0020] The first-order voltage data at the current moment is obtained from the first-order relation value table to obtain the first-order target voltage value.

[0021] The second-order voltage data at the current moment is obtained according to the second-order relation value table to obtain the second-order target voltage value;

[0022] If the first-order target voltage value is less than a preset first-order voltage threshold, and the second-order target voltage value is greater than a preset second-order voltage threshold, then the point at the current moment is taken as the feature inflection point.

[0023] According to other embodiments of the energy balancing method of the present invention, the step of calculating the balanced energy based on the characteristic energy level, the battery health status value, and a preset standard capacity includes:

[0024] Obtain the minimum value of the characteristic charge to get the minimum characteristic charge;

[0025] Obtain the minimum value of the battery health status value to get the minimum status value;

[0026] The state difference is obtained by calculating the difference between the battery health state value and the minimum state value.

[0027] The balanced power is obtained by performing a balanced calculation based on the characteristic power, the minimum characteristic power, the state difference, and the preset standard capacity.

[0028] According to other embodiments of the energy balancing method of the present invention, the step of numerically calculating the balanced energy based on the characteristic energy, the minimum characteristic energy, the state difference, and the preset standard capacity includes:

[0029] The capacity difference is calculated by multiplying the state difference value and the preset standard capacity.

[0030] The minimum characteristic charge and the capacity difference are added together to obtain the charge error value;

[0031] The difference between the characteristic power and the power error value is calculated to obtain the balanced power.

[0032] According to other embodiments of the energy balancing method of the present invention, the step of performing energy balancing on the power supply battery based on the balanced charge includes:

[0033] The equalization time is obtained by dividing the equalization power value by the preset equalization current value.

[0034] The power supply battery is equilibrated according to the equilibration time and preset equilibration rules.

[0035] According to other embodiments of the energy balancing method of the present invention, before obtaining the cell voltage of the battery cell to obtain cell voltage data, the method further includes:

[0036] Obtain the current temperature of the power supply battery and get the current temperature value;

[0037] If the current temperature value is less than a preset temperature threshold, the power supply battery is heated to make the current temperature value greater than the preset temperature threshold.

[0038] Fully charge the power supply battery;

[0039] The power supply battery is left to stand for the preset resting time to discharge it.

[0040] Secondly, one embodiment of the present invention provides an energy balancing device applied to a vehicle's power supply battery, comprising:

[0041] The single cell voltage acquisition module is used to acquire the single cell voltage of the battery cell to obtain single cell voltage data; wherein, the single cell voltage is the voltage of the battery after it is fully charged and left to stand for a preset time before being discharged.

[0042] The differential voltage calculation module is used to perform differential calculations on the individual unit voltage data if the individual unit voltage data is equal to or higher than a preset individual unit voltage threshold, so as to obtain differential voltage data.

[0043] The inflection point search module is used to search for inflection points in the differential voltage data according to a pre-built relational value table to obtain characteristic inflection points; wherein, the relational value table is constructed based on the pairing data of the differential voltage data and time.

[0044] The feature power acquisition module is used to acquire the power of the battery cell based on the feature inflection point to obtain the feature power.

[0045] A health status acquisition module is used to acquire the health status value of the power supply battery to obtain the battery health status value;

[0046] The balanced power calculation module is used to perform balanced calculations based on the characteristic power, the battery health status value, and the preset standard capacity to obtain the balanced power.

[0047] An energy balancing module is used to balance the energy of the power supply battery based on the balanced charge level.

[0048] The energy balancing device of this invention has at least the following beneficial effects: When a battery cell is left to stand still for a preset time, the battery cell is in a static state. The cell voltage acquisition module acquires the cell voltage when the battery cell is in a static state to obtain cell voltage data. The differential voltage calculation module compares the cell voltage data with a preset cell voltage threshold. If the cell voltage data is equal to or higher than the preset cell voltage threshold, the differential voltage data is calculated to obtain differential voltage data. The inflection point search module constructs a relational value table based on the pairing data of differential voltage data and time, and performs inflection point search on the differential voltage data according to the relational value table to obtain characteristic inflection points. The characteristic charge acquisition module acquires the charge value of the battery cell located at the characteristic inflection point to obtain characteristic charge. The health status acquisition module acquires the health status value of the power supply battery to obtain the battery health status value. The balancing charge calculation module performs balancing calculation based on the characteristic charge, the battery health status value, and the preset standard capacity to obtain the balanced charge. The energy balancing module performs energy balancing on the power supply battery based on the balanced charge, which can improve the accuracy of the acquired balanced charge, thereby improving the accuracy of energy balancing on the power supply battery.

[0049] Thirdly, one embodiment of the present invention provides an energy balancing device, comprising:

[0050] At least one processor, and,

[0051] A memory communicatively connected to the at least one processor; wherein,

[0052] The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the energy balancing method as described in the first aspect.

[0053] Fourthly, one embodiment of the present invention provides a computer-readable storage medium storing computer-executable instructions for causing a computer to perform the energy balancing method as described in the first aspect.

[0054] Other features and advantages of this application will be set forth in the following description and will be apparent in part from the description or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the description and the accompanying drawings. Attached Figure Description

[0055] Figure 1 This is a schematic flowchart of a specific embodiment of the energy balancing method in this invention;

[0056] Figure 2 yes Figure 1A schematic diagram of a specific embodiment of step S102;

[0057] Figure 3 yes Figure 1 A schematic diagram of a specific embodiment of step S103;

[0058] Figure 4 yes Figure 1 A schematic flowchart of a specific embodiment of step S106;

[0059] Figure 5 yes Figure 1 A schematic flowchart of a specific embodiment of step S404;

[0060] Figure 6 yes Figure 1 A schematic flowchart of a specific embodiment of step S107;

[0061] Figure 7 This is a schematic flowchart of another specific embodiment of the energy balancing method in this invention;

[0062] Figure 8 This is a schematic flowchart of another specific embodiment of the energy balancing method in this invention;

[0063] Figure 9 This is a block diagram of a specific embodiment of the energy balancing device in this invention.

[0064] Figure 10 This is a schematic diagram of a specific embodiment of the relational value table in this invention;

[0065] Figure 11 This is a schematic diagram of another specific embodiment of the relational value table in the present invention.

[0066] Modules 901, 902, 903, 904, 905, 906, 907, including: 901, 908, 909; 900, 901, 902, 903, 904, 905, 906, 907, 908, 909. Detailed Implementation

[0067] The following will describe the concept and technical effects of the present invention clearly and completely with reference to embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

[0068] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0069] It should be noted that although the system diagram shows functional modules and the flowchart shows the logical order, in some cases, the steps shown or described may be executed in a different order than the module division in the system or the order in the flowchart.

[0070] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0071] In the description of the embodiments of the present invention, the term "several" means one or more, and the term "multiple" means two or more. The terms "greater than," "less than," and "exceeding" should be understood as excluding the stated number, while the terms "above," "below," and "within" should be understood as including the stated number. The terms "first" and "second" should be understood as distinguishing technical features, and not as indicating or implying relative importance, the number of indicated technical features, or the order of the indicated technical features.

[0072] First, let's analyze the technical terms used in this application:

[0073] SOC refers to the state of charge of a battery, which is mainly used to reflect the remaining capacity of the battery. It is numerically defined as the ratio of the remaining capacity to the battery capacity.

[0074] Battery Management System (BMS), also known as battery nanny or battery steward, is mainly used for intelligent management and maintenance of each battery cell, preventing overcharging and over-discharging, extending battery life, and monitoring battery status.

[0075] SOH refers to the battery's capacity, health, and performance status. Simply put, it is the ratio of the battery's performance parameters to its nominal parameters after a period of use. A newly manufactured battery is 100%, while a completely scrapped battery is 0%.

[0076] Automotive power batteries are often connected in series to form a pack. However, due to batch and material control issues during manufacturing, individual battery cells exhibit inconsistencies in capacity and internal resistance. This inconsistency directly reduces the pack's energy utilization rate. Without balancing, these inconsistencies will further amplify with varying self-discharge rates among individual cells, continuously weakening the pack's energy utilization. Therefore, balancing individual battery cells according to certain standards to maintain consistency is crucial. On the other hand, during battery use, cells operating at high charge levels for extended periods age faster than others, ultimately exhibiting different aging trajectories. This also impacts balancing strategies. Within the pack, the cell with the lowest State of Harm (SOH) determines the pack's SOH, and understanding the SOH values ​​of each cell is equally important for guiding subsequent balancing strategies. Therefore, battery consistency and the SOH of each individual cell become crucial indicators for the state diagnosis of power batteries.

[0077] A method for diagnosing (balancing) the consistency of battery cells in an automotive BMS battery system determines the balancing amount of each cell based on the voltage difference at the end of charging. However, because the internal resistance of battery cells increases with aging, and the increase in internal resistance varies among cells, for cells with low capacity but a large increase in internal resistance, their voltage may not be at its highest during the middle of charging, but may reach its highest voltage at the end of charging. In this case, the balancing amount determined by the voltage difference will have a large error.

[0078] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes an energy balancing method that can improve the accuracy of the obtained balanced charge, thereby improving the accuracy of energy balancing in power supply batteries.

[0079] Please refer to Figure 1 , Figure 1 A flowchart illustrating the energy balancing method in an embodiment of the present invention is shown. In some embodiments, it is applied to the power supply battery of a vehicle, specifically including but not limited to steps S101 to S107.

[0080] Step S101: Obtain the individual cell voltage of the battery cell to obtain individual cell voltage data; wherein, the individual cell voltage is the voltage of the battery after it has been fully charged and left to stand for a preset time before being discharged.

[0081] Step S102: If the individual voltage data is equal to or higher than the preset individual voltage threshold, perform differential calculation on the individual voltage data to obtain differential voltage data.

[0082] Step S103: Find the inflection point of the differential voltage data according to the pre-constructed relational value table to obtain the characteristic inflection point; wherein, the relational value table is constructed based on the pairing data of differential voltage data and time.

[0083] Step S104: Obtain the battery cell's charge level based on the characteristic inflection point to obtain the characteristic charge level;

[0084] Step S105: Obtain the health status value of the power supply battery to obtain the battery health status value;

[0085] Step S106: Perform a balancing calculation based on the characteristic charge level, battery health status value, and preset standard capacity to obtain the balanced charge level;

[0086] Step S107: Perform energy balancing on the power supply battery based on the equalization charge.

[0087] By executing steps S101 to S107, when a battery cell is left to stand for a preset time, the battery cell is in a static state. The cell voltage after discharge is obtained to acquire cell voltage data. The cell voltage data is compared with a preset cell voltage threshold. If the cell voltage data is equal to or higher than the preset cell voltage threshold, the cell voltage data is differentiated to obtain differential voltage data. A relationship value table is constructed based on the pairing data of differential voltage data and time. Inflection points are found in the differential voltage data according to the relationship value table to obtain characteristic inflection points. The cell charge value at the characteristic inflection point is obtained to obtain characteristic charge. The health status value of the power supply battery is obtained to obtain the battery health status value. Based on the characteristic charge, battery health status value, and preset standard capacity, a balancing calculation is performed to obtain the balanced charge. Energy balancing of the power supply battery based on the balanced charge can improve the accuracy of the obtained balanced charge, thereby improving the accuracy of energy balancing of the power supply battery.

[0088] Before executing step S101, the BMS battery system acquires the change value of the current of the power supply battery and the current temperature of the power supply battery to obtain the current change value and the current temperature value. The current change value is compared with a preset current change threshold, and the current temperature value is compared with a preset temperature threshold. If the current change value is within the preset current change threshold and the current temperature value is greater than the preset temperature threshold, step S101 is executed.

[0089] The preset current change threshold is preferably +2A or -2A in this application, and the preset temperature threshold is preferably 20℃. However, this application does not specifically limit the preset current change threshold and the preset temperature threshold.

[0090] Specifically, if the current change value is within [-2A, +2A] and the battery discharge rate is less than 1C, then it is determined whether the current temperature value is greater than a preset temperature threshold. If the current change value is not within [-2A, +2A], or the battery discharge rate is not less than 1C, then a new current change value is obtained for judgment, until the above conditions are met. If the current temperature value is greater than 20℃, then the voltage change and the estimated remaining power corresponding to the voltage change value are obtained. If the current temperature value is less than 20℃, then a new current change value is obtained for judgment, until the above conditions are met. Among these, if the current change value is within [-2A, +2A], the current current can be considered a constant current. If the current is a constant current and the current temperature value is greater than 20℃, the voltage drop slope will change significantly during the charging or discharging process of the power supply battery, making the obtained data more distinctive and improving the accuracy of the calculated balanced power.

[0091] It should be noted that the current change value is calculated by the BMS battery system after measuring relevant parameters. The current temperature value is measured by the BMS battery system.

[0092] In step S101 of some embodiments, the power supply battery is fully charged, then left to stand for a preset time, and then the power supply battery is discharged. The individual cell voltage of each battery cell during the discharge process is acquired in real time to obtain individual cell voltage data.

[0093] It should be noted that a single cell voltage variable is preset for each battery cell, and the single cell voltage variable is used to count the single cell voltage corresponding to the battery cell.

[0094] Please refer to Figure 2 , Figure 2 A flowchart illustrating the energy equalization method in an embodiment of the present invention is shown. In some embodiments, the differential voltage data includes first-order voltage data and second-order voltage data, and step S102 includes, but is not limited to, steps S201 to S202.

[0095] Step S201: Perform differential calculations on the individual voltage data to obtain first-order voltage data;

[0096] Step S202: Perform differential calculations on the first-order voltage data to obtain the second-order voltage data.

[0097] In step S201 of some embodiments, the first-order derivative of the individual voltage data is calculated to obtain the first-order voltage data, which can obtain the data after the first-order derivative of the individual voltage data.

[0098] In step S202 of some embodiments, the first-order voltage data is subjected to first-order differential calculation to obtain second-order voltage data, or the individual voltage data is subjected to second-order differential calculation to obtain second-order voltage data, thereby obtaining the data after second-order differential of the individual voltage data.

[0099] It should be noted that the preset individual cell voltage threshold is preferably 3.2V in this application. The preset individual cell voltage threshold can be selected according to the actual situation, and this application does not specifically limit the preset individual cell voltage threshold. When the individual cell voltage data are all greater than or equal to the preset individual cell voltage threshold, the accuracy of the obtained balanced power can be improved.

[0100] Please refer to Figure 3 , Figure 3 A flowchart illustrating the energy balancing method in an embodiment of the present invention is shown. In some embodiments, the relational value table includes a first-order relational value table and a second-order relational value table. The first-order relational value table is constructed based on the paired data of first-order voltage data and time, and the second-order relational value table is constructed based on the paired data of second-order voltage data and time. Step S103 includes, but is not limited to, steps S301 to S303.

[0101] Step S301: Obtain the first-order voltage data at the current moment according to the first-order relation value table, and obtain the first-order target voltage value;

[0102] Step S302: Obtain the second-order voltage data at the current moment according to the second-order relation value table, and obtain the second-order target voltage value;

[0103] Step S303: If the first-order target voltage value is less than the preset first-order voltage threshold and the second-order target voltage value is greater than the preset second-order voltage threshold, the current point is taken as the feature inflection point.

[0104] By executing steps S301 to S303, the first-order voltage data at the current moment is retrieved in real time according to the first-order relational value table to obtain the first-order target voltage value. Similarly, the second-order voltage data at the current moment is retrieved in real time according to the second-order relational value table to obtain the second-order target voltage value. The first-order target voltage value is compared with a preset first-order voltage threshold. If the first-order target voltage value is less than the preset first-order voltage threshold, the second-order target voltage value is then compared with a preset second-order voltage threshold. This process continues until the second-order target voltage value at the current moment is greater than the preset second-order voltage threshold. The point corresponding to the current moment is then taken as the feature inflection point, thus obtaining the required feature inflection point.

[0105] It should be noted that the corresponding feature inflection points are obtained based on the first-order target voltage value and the second-order target voltage value of each battery cell, until the feature inflection point of each battery cell is obtained. If the feature inflection point of each battery cell is not obtained, the obtained feature inflection points are stored, and the process returns to step S301 to search for battery cells for which no feature inflection point has been obtained, until the feature inflection point of each battery cell is found.

[0106] For example, let the current time be ti, i be a positive integer, the first-order target voltage value be V1(ti), and the second-order target voltage value be V2(ti). If the first-order target voltage value V1(ti) is less than the preset first-order voltage threshold when the current time ti is the same as the current time t1, the comparison and judgment continue to change with time until the second-order target voltage value V2(ti) is greater than the preset second-order voltage threshold when the current time ti is the same as the current time t2. Then the characteristic inflection point is the point corresponding to time t2.

[0107] In step S301 of some embodiments, the current discharge time is obtained, and the time and corresponding first-order voltage data are paired to obtain first-order paired data. The first-order voltage data is used as the y-axis coefficient, and the time is used as the x-axis coefficient. A curve is plotted based on the first-order paired data to construct a first-order relationship value table. The plotted curve is specifically referred to... Figure 10 and Figure 11 , Figure 10 The curve near the first characteristic inflection point, Figure 11 The curve is located near the inflection point of the second characteristic.

[0108] In step S302 of some embodiments, the current discharge time is obtained, and the time and the corresponding second-order voltage data are paired to obtain second-order paired data. The second-order voltage data is used as the y-axis coefficient and the time is used as the x-axis coefficient. A curve is plotted based on the second-order paired data to construct a second-order relationship value table.

[0109] In step S303 of some embodiments, the preset first-order voltage threshold is preferably -15 in this application. The preset first-order voltage threshold is selected based on the value of a point located near the feature inflection point, and can be selected according to the actual situation. This application does not impose a specific limitation on it. The preset second-order voltage threshold is preferably 0.2 in this application. The preset second-order voltage threshold is selected based on the value of a point located near the feature inflection point, and can be selected according to the actual situation. This application does not impose a specific limitation on it.

[0110] In step S104 of some embodiments, a variable is preset, which is used to count the amount of electricity discharged by the battery after the power supply battery starts discharging in real time.

[0111] An array variable is predefined, with its length set to the number of individual battery cells. This array variable stores the amount of electricity discharged by each battery cell when it reaches a characteristic inflection point, i.e., the characteristic charge, for subsequent calculations. Specifically, when a battery cell reaches a characteristic inflection point, the corresponding charge value is retrieved from the aforementioned variable and stored in the array variable to obtain the characteristic charge of that battery cell.

[0112] In step S105 of some embodiments, the health status of each individual cell in the power supply battery is obtained to acquire the health status value of each individual cell, and a battery health status value is obtained. The battery health status value is estimated by the BMS battery system.

[0113] Please refer to Figure 4 , Figure 4 A flowchart illustrating the energy balancing method in an embodiment of the present invention is shown. In some embodiments, step S106 includes, but is not limited to, steps S401 to S404.

[0114] Step S401: Obtain the minimum value of the characteristic charge to get the minimum characteristic charge;

[0115] Step S402: Obtain the minimum value of the battery health status value to get the minimum status value;

[0116] Step S403: Calculate the difference between the battery health status value and the minimum status value to obtain the status difference;

[0117] Step S404: Perform balancing calculations based on characteristic power, minimum characteristic power, state difference, and preset standard capacity to obtain balanced power.

[0118] By executing steps S401 to S404, the characteristic charge values ​​of each battery cell are compared, and the minimum characteristic charge value is obtained based on the comparison. The battery health status values ​​of each battery cell are then compared, and the minimum battery health status value is obtained based on the comparison. The minimum health status value is then subtracted from the minimum health status value to obtain the health difference. A balancing calculation is then performed based on the characteristic charge, the minimum characteristic charge, the health difference, and a preset standard capacity to obtain the balanced charge. This improves the accuracy of the obtained balanced charge, thereby enhancing the accuracy of energy balancing in the power supply batteries.

[0119] Please refer to Figure 5 , Figure 5 A flowchart illustrating the energy balancing method in an embodiment of the present invention is shown. In some embodiments, step S404 includes, but is not limited to, steps S501 to S503.

[0120] Step S501: Multiply the state difference value and the preset standard capacity to calculate the capacity difference value;

[0121] Step S502: Add the minimum characteristic charge and the capacity difference to calculate the charge error value;

[0122] Step S503: Calculate the difference between the characteristic power and the power error value to obtain the balanced power.

[0123] By executing steps S501 to S503, the state difference of each battery cell is multiplied by the preset standard capacity to obtain the capacity difference of each battery cell. The minimum characteristic charge is added to the capacity difference of each battery cell to obtain the charge error value of each battery cell. The characteristic charge of each battery cell is subtracted from the corresponding charge error value to obtain the balanced charge of each battery cell. This improves the accuracy of the obtained balanced charge, thereby improving the accuracy of energy balancing of the power supply battery.

[0124] Specifically, steps S501 to S503 can be calculated according to the formula: Q_balance = Image_Q_mAH_dsg - Q_min_dsg - δSOH_cell * FullCapacity. Where Q_balance is the balanced charge, Image_Q_mAH_dsg is the characteristic charge, Q_min_dsg is the minimum characteristic charge, δSOH_cell is the state difference, and FullCapacity is the preset standard capacity.

[0125] Please refer to Figure 6 , Figure 6 A flowchart illustrating the energy balancing method in an embodiment of the present invention is shown. In some embodiments, step S107 includes, but is not limited to, steps S601 to S602.

[0126] Step S601: Divide the equalization power and the preset equalization current value to obtain the equalization time;

[0127] Step S602: Perform energy balancing on the power supply battery according to the balancing time and preset balancing rules.

[0128] By executing steps S601 to S602, a pre-set equalization current is used according to the energy equalization standard. The amount of electricity is obtained by multiplying the current and time. Therefore, the time required for energy equalization is calculated by dividing the equalization amount by the pre-set equalization current value. The equalization time is obtained by performing energy equalization on the power supply battery according to the equalization time and the pre-set equalization rules, which can improve the accuracy of energy equalization of the power supply battery.

[0129] It should be noted that a timer is set for each individual battery cell. While performing energy balancing on each cell of the power supply battery, each timer starts simultaneously. The timer for each cell decreases the balancing time according to a preset decrement duration, and after each decrement, the remaining time is obtained. The remaining time is then checked. If the remaining time is zero, energy balancing is complete, and the balancing process stops. If the remaining time is not zero, meaning energy balancing is incomplete but the power supply battery has been powered off, the remaining time is stored. Upon powering back on the power supply battery, the remaining time is set as the balancing charge. This process is repeated until energy balancing is complete, which improves the accuracy of energy balancing.

[0130] Please refer to Figure 7 , Figure 7 A flowchart illustrating the energy balancing method in an embodiment of the present invention is shown. In some embodiments, step S602 includes, but is not limited to, steps S701 to S704.

[0131] Step S701: Obtain the current temperature of the power supply battery and get the current temperature value;

[0132] Step S702: If the current temperature value is less than the preset temperature threshold, heat the power supply battery to make the current temperature value greater than the preset temperature threshold.

[0133] Step S703: Fully charge the power supply battery;

[0134] Step S704: Allow the power supply battery to stand for the preset standing time to discharge the power supply battery.

[0135] By executing steps S701 to S704, the BMS battery system establishes a communication link with the charging device and the heating device. The BMS battery system acquires the temperature of the power supply battery. When the temperature is below 20°C, the BMS battery system sends a control signal to control the heating device to raise the battery temperature to above 20°C. The BMS sends a control signal to control the charging device to charge the power supply battery until it is fully charged. While maintaining a temperature above 20°C, the power supply battery is left to stand for a preset time. The BMS battery system then sends a control signal to control the charging device to discharge the power supply battery. The discharge current is 0.33C to ensure that the lowest voltage cell in the power supply battery reaches its discharge cutoff voltage, improving the accuracy of the obtained balanced charge and thus enhancing the accuracy of energy balancing of the power supply battery.

[0136] It should be noted that the charging equipment and heating equipment can create suitable conditions for the implementation of steps S101 to S107.

[0137] Please refer to Figure 8 , Figure 8 A flowchart illustrating the energy balancing method in an embodiment of the present invention is shown. In some embodiments, it specifically includes:

[0138] The Battery Management System (BMS) periodically acquires the battery differential voltage status and notifies the user via the vehicle to perform maintenance. The user connects the vehicle to the charging equipment, establishing a communication link between the BMS and the charging equipment, and also establishes a communication link between the BMS and the heating equipment, thus entering maintenance mode. Maintenance mode includes: the BMS assessing the battery temperature; if the temperature is below 20°C, the BMS controls the heating equipment to raise the battery temperature above 20°C. The BMS controls the charging equipment to fully charge the battery and maintains the temperature above 20°C for a preset resting time. The BMS controls the charging equipment to discharge the battery at 0.33C, ensuring the voltage of the smallest individual cell reaches the discharge cutoff voltage. The BMS records the individual cell voltage data during the discharge process, identifies local characteristics of the individual cell voltage data, records relevant data, completes the consistency determination of the battery, identifies the State of Harmony (SOH) of each individual cell, and calculates the balancing amount required for each individual cell. Simultaneously, the BMS calibrates the SOC of the battery. The BMS battery system controls the charging equipment to charge the power supply battery, charging it to the user-set SOC value at a specified power. Furthermore, based on the calculated equalization charge, the BMS battery system performs energy balancing of each battery cell during subsequent operation, which improves the accuracy of the obtained equalization charge and thus enhances the accuracy of energy balancing of the power supply battery.

[0139] In addition, this application also discloses an energy balancing device, please refer to... Figure 9 , Figure 9 This invention discloses a block diagram of an energy balancing device according to an embodiment of the present invention. The energy balancing device is applied to the power supply battery of an automobile and can realize the above-described energy balancing method. The energy balancing device includes: a single-cell voltage acquisition module 901, a differential voltage calculation module 902, an inflection point search module 903, a characteristic charge acquisition module 904, a health status acquisition module 905, a balanced charge calculation module 906, and an energy balancing module 907. The single-cell voltage acquisition module 901, differential voltage calculation module 902, inflection point search module 903, characteristic charge acquisition module 904, health status acquisition module 905, balanced charge calculation module 906, and energy balancing module 907 are all communicatively connected.

[0140] The single-cell voltage acquisition module 901 acquires the single-cell voltage of the battery cells after a preset resting time to obtain single-cell voltage data. If the single-cell voltage data is equal to or higher than a preset single-cell voltage threshold, the differential voltage calculation module 902 performs differential calculation on the single-cell voltage data to obtain differential voltage data. The inflection point search module 903 searches for inflection points in the differential voltage data according to a pre-constructed relational value table to obtain characteristic inflection points; wherein, the relational value table is constructed based on the pairing data of differential voltage data and time. The characteristic charge acquisition module 904 acquires the charge of the battery cells based on the characteristic inflection points to obtain characteristic charge. The health status acquisition module 905 acquires the health status value of the power supply battery to obtain the battery health status value. The equalization charge calculation module 906 performs equalization calculation based on the characteristic charge, the battery health status value, and the preset standard capacity to obtain the equalization charge. The energy equalization module 907 performs energy equalization on the power supply battery based on the equalization charge.

[0141] When a battery cell is left to stand for a preset time, it is in a static state. The cell voltage acquisition module 901 acquires the cell voltage while the cell is in this static state to obtain cell voltage data, and transmits the cell voltage data to the differential voltage calculation module 902. The differential voltage calculation module 902 compares the cell voltage data with a preset cell voltage threshold. If the cell voltage data is equal to or higher than the preset cell voltage threshold, it performs differential calculation on the cell voltage data to obtain differential voltage data, and transmits the differential voltage data to the inflection point lookup module 903. The inflection point lookup module 903 constructs a relationship value table based on the pairing data of differential voltage data and time, performs inflection point lookup on the differential voltage data according to the relationship value table to obtain characteristic inflection points, and transmits the characteristic inflection points to the characteristic charge acquisition module 904. The characteristic charge acquisition module 904 acquires the charge value of the battery cell at the characteristic inflection point to obtain the characteristic charge, and transmits the characteristic charge to the equalization charge calculation module 906. The health status acquisition module 905 acquires the health status value of the power supply battery to obtain the battery health status value, and transmits the battery health status value to the equalization power calculation module 906. The equalization power calculation module 906 performs equalization calculations based on the characteristic power level, the battery health status value, and a preset standard capacity to obtain the equalization power, and transmits the equalization power to the energy equalization module 907. The energy equalization module 907 performs energy equalization on the power supply battery based on the equalization power, which improves the accuracy of the acquired equalization power and thus improves the accuracy of energy equalization of the power supply battery.

[0142] The operation process of the energy equalization device in this embodiment is specifically described above. Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7The steps S101 to S107, S201 and S202, S301 to S303, S401 to S404, S501 to S503, S601 and S602 and S701 to S704 of the energy balance method are not described in detail here.

[0143] Another embodiment of the present invention discloses an energy balancing device, comprising: at least one processor, and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform, for example... Figure 1 Control method steps S101 to S107 Figure 2 Control method steps S201 and S202 Figure 3 Control method steps S301 to S303 Figure 4 Control method steps S401 to S404 Figure 5 Control method steps S501 to S503 Figure 6 The control method steps S601 and S602 and Figure 7 The energy balance method in steps S701 to S704 of the control method.

[0144] Another embodiment of the present invention discloses a storage medium, the storage medium comprising: storing computer-executable instructions for causing a computer to perform... Figure 1 Control method steps S101 to S107 Figure 2 Control method steps S201 and S202 Figure 3 Control method steps S301 to S303 Figure 4 Control method steps S401 to S404 Figure 5 Control method steps S501 to S503 Figure 6 The control method steps S601 and S602 and Figure 7 The energy balance method in steps S701 to S704 of the control method.

[0145] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0146] It will be understood by those skilled in the art that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, as is known to those skilled in the art, communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0147] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. An energy balancing method applied to the power supply battery of an automobile, characterized in that, include: The individual cell voltage of the battery cell is obtained to obtain individual cell voltage data; wherein, the individual cell voltage is the voltage of the battery after it has been fully charged and left to stand for a preset time before being discharged. If the individual cell voltage data is equal to or higher than a preset individual cell voltage threshold, the individual cell voltage data is differentiated to obtain differential voltage data; The differential voltage data is searched for inflection points according to a pre-constructed relational value table to obtain characteristic inflection points; wherein, the relational value table is constructed based on the pairing data of the differential voltage data and time. The power level of the battery cell is obtained based on the characteristic inflection point to obtain the characteristic power level; Obtain the health status value of the power supply battery to obtain the battery health status value; The balanced power is obtained by performing a balanced calculation based on the characteristic power level, the battery health status value, and the preset standard capacity. The power supply battery is energy balanced according to the balanced charge level. The differential voltage data includes first-order voltage data and second-order voltage data. The differential calculation of the individual voltage data to obtain the differential voltage data includes: The individual voltage data is differentiated to obtain the first-order voltage data; The first-order voltage data is differentiated to obtain the second-order voltage data; The relational value table includes a first-order relational value table and a second-order relational value table. The step of searching for inflection points in the differential voltage data based on the pre-constructed relational value table to obtain characteristic inflection points includes: The first-order voltage data at the current moment is obtained from the first-order relation value table to obtain the first-order target voltage value. The second-order voltage data at the current moment is obtained according to the second-order relation value table to obtain the second-order target voltage value; If the first-order target voltage value is less than a preset first-order voltage threshold, and the second-order target voltage value is greater than a preset second-order voltage threshold, then the current point is taken as the feature inflection point. The step of performing a balanced calculation based on the characteristic power level, the battery health status value, and the preset standard capacity to obtain the balanced power level includes: Obtain the minimum value of the characteristic charge to get the minimum characteristic charge; Obtain the minimum value of the battery health status value to get the minimum status value; The state difference is obtained by calculating the difference between the battery health state value and the minimum state value. The balanced power is obtained by performing a balanced calculation based on the characteristic power, the minimum characteristic power, the state difference, and the preset standard capacity.

2. The energy balancing method according to claim 1, characterized in that, The first-order relational value table is constructed based on the paired data of the first-order voltage data and time, and the second-order relational value table is constructed based on the paired data of the second-order voltage data and time.

3. The energy balancing method according to claim 1, characterized in that, The step of performing a balancing calculation based on the characteristic energy level, the minimum characteristic energy level, the state difference, and the preset standard capacity to obtain the balanced energy level includes: The capacity difference is calculated by multiplying the state difference value and the preset standard capacity. The minimum characteristic charge and the capacity difference are added together to obtain the charge error value; The difference between the characteristic power and the power error value is calculated to obtain the balanced power.

4. The energy balancing method according to claim 3, characterized in that, The step of balancing the energy of the power supply battery based on the balanced charge includes: The equalization time is obtained by dividing the equalization power value by the preset equalization current value. The power supply battery is equilibrated according to the equilibration time and preset equilibration rules.

5. The energy balancing method according to claim 1, characterized in that, Before obtaining the cell voltage of a battery cell to obtain cell voltage data, the method further includes: Obtain the current temperature of the power supply battery and get the current temperature value; If the current temperature value is less than a preset temperature threshold, the power supply battery is heated to make the current temperature value greater than the preset temperature threshold. Fully charge the power supply battery; The power supply battery is left to stand for the preset time to discharge.

6. An energy balancing device for use in a vehicle's power supply battery, characterized in that, include: The single cell voltage acquisition module is used to acquire the single cell voltage of the battery cell to obtain single cell voltage data; wherein, the single cell voltage is the voltage of the battery after it is fully charged and left to stand for a preset time before being discharged. The differential voltage calculation module is used to perform differential calculations on the individual unit voltage data if the individual unit voltage data is equal to or higher than a preset individual unit voltage threshold, so as to obtain differential voltage data. The inflection point search module is used to search for inflection points in the differential voltage data according to a pre-built relational value table to obtain characteristic inflection points; wherein, the relational value table is constructed based on the pairing data of the differential voltage data and time. The feature power acquisition module is used to acquire the power of the battery cell based on the feature inflection point to obtain the feature power. A health status acquisition module is used to acquire the health status value of the power supply battery to obtain the battery health status value; The balanced power calculation module is used to perform balanced calculations based on the characteristic power, the battery health status value, and the preset standard capacity to obtain the balanced power. An energy balancing module is used to balance the energy of the power supply battery according to the balanced charge level. The differential voltage data includes first-order voltage data and second-order voltage data. The differential calculation of the individual voltage data to obtain the differential voltage data includes: The individual voltage data is differentiated to obtain the first-order voltage data; The first-order voltage data is differentiated to obtain the second-order voltage data; The relational value table includes a first-order relational value table and a second-order relational value table. The step of searching for inflection points in the differential voltage data based on the pre-constructed relational value table to obtain characteristic inflection points includes: The first-order voltage data at the current moment is obtained from the first-order relation value table to obtain the first-order target voltage value. The second-order voltage data at the current moment is obtained according to the second-order relation value table to obtain the second-order target voltage value; If the first-order target voltage value is less than a preset first-order voltage threshold, and the second-order target voltage value is greater than a preset second-order voltage threshold, then the current point is taken as the feature inflection point. The step of performing a balanced calculation based on the characteristic power level, the battery health status value, and the preset standard capacity to obtain the balanced power level includes: Obtain the minimum value of the characteristic charge to get the minimum characteristic charge; Obtain the minimum value of the battery health status value to get the minimum status value; The state difference is obtained by calculating the difference between the battery health state value and the minimum state value. The balanced power is obtained by performing a balanced calculation based on the characteristic power, the minimum characteristic power, the state difference, and the preset standard capacity.

7. An energy balancing device, characterized in that, include: At least one processor, and, A memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the energy balancing method as described in any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions for causing a computer to perform the energy balancing method as described in any one of claims 1 to 5.

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