Energy balancing methods, apparatus, equipment and storage media

Abstract

This invention discloses an energy balancing method, apparatus, device, and storage medium applied to automotive power batteries. The energy balancing method includes: acquiring the current cell voltage of a battery cell after a preset charging or discharging time to obtain cell voltage data; if the cell voltage data is within a preset cell voltage range, performing differential calculations on the 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 cell charge based on the characteristic inflection points to obtain characteristic charge; performing balancing calculations based on the target characteristic charge and the characteristic charge to obtain balanced charge; wherein the target characteristic charge includes the maximum or minimum value of the characteristic charge; and performing energy balancing on the power supply battery based on the balanced charge. This invention can perform energy balancing on the power supply battery during charging or discharging.

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, one method for balancing power batteries used in automobiles, especially lithium iron phosphate batteries, involves adjusting the energy of a single cell when the state of charge (SOC) is low, as the cell voltage is not in the OCV plateau region. In this case, the accurate SOC value is obtained by looking up the OCV value in a table, and the balancing energy is obtained based on the SOC difference. However, this requires the power battery to be left to stand. Therefore, how to balance the energy of the power supply battery without having to leave it to stand is a problem that urgently needs to be solved. 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 perform energy balancing on a power supply battery during charging or discharging.

[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] Obtain the current cell voltage after a preset charging or discharging time for a single battery cell to obtain cell voltage data;

[0009] If the individual unit voltage data is within a preset individual unit voltage range, perform differential calculation on the individual unit voltage data 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] The balanced electricity is obtained by performing a balancing calculation based on the target characteristic electricity and the characteristic electricity; wherein, the target characteristic electricity includes the maximum value or the minimum value of the characteristic electricity.

[0013] The power supply battery is equilibrated based on the balanced charge level.

[0014] The energy balancing method of this invention has at least the following beneficial effects: After each battery cell has been charged or discharged for a preset time, the current voltage of each battery cell is acquired in real time to obtain the battery cell voltage data. The battery cell voltage data is compared with a preset battery cell voltage range. If the battery cell voltage data is within the preset battery cell voltage range, the differential calculation is performed on the battery cell voltage data of each battery cell to obtain the differential voltage data of each battery cell. The differential voltage data is paired with time to obtain paired data. A relational value table corresponding to each battery cell is constructed based on the paired data. The inflection point of the differential voltage data is found based on the relational value table to obtain the characteristic inflection point corresponding to each battery cell. The charge of the battery cell corresponding to the characteristic inflection point is obtained to obtain the characteristic charge of each battery cell. The target characteristic charge is obtained from the characteristic charge. The balancing calculation is performed based on the target characteristic charge and the characteristic charge to obtain the balanced charge of each battery cell. The energy balancing of the entire power supply battery is performed based on the balanced charge of each battery cell, which can perform energy balancing of the power supply battery during the charging or discharging process.

[0015] According to other embodiments of the energy balancing method of the present invention, the individual cell voltage data includes charging voltage data and discharging voltage data, wherein the charging voltage data is the individual cell voltage data obtained during the charging process, and the discharging voltage data is the individual cell voltage data obtained during the discharging process, and the step of performing differential calculation on the individual cell voltage data to obtain differential voltage data includes:

[0016] If the single-unit voltage data is the charging voltage data, perform second-order differential calculation on the charging voltage data to obtain second-order charging voltage data;

[0017] If the single-cell voltage data is the discharge voltage data, perform a first-order differential calculation on the discharge voltage data to obtain first-order discharge voltage data, and perform a second-order differential calculation on the discharge voltage data to obtain second-order discharge voltage data.

[0018] According to other embodiments of the energy balancing method of the present invention, the relational value table includes a second-order charging relational value table, which is constructed based on the pairing data of the second-order charging voltage and time. The step of performing inflection point lookup on the differential voltage data based on the pre-constructed relational value table to obtain characteristic inflection points includes:

[0019] The second-order charging voltage data at the current moment is obtained according to the second-order charging relationship value table to obtain the second-order charging target value;

[0020] If the second-order charging target value is less than a preset first charging voltage threshold, and the second-order charging target value is greater than a preset second charging voltage threshold, then the point at the current moment is taken as the feature inflection point.

[0021] According to other embodiments of the energy balancing method of the present invention, the step of performing balancing calculations based on the target characteristic quantity and the characteristic quantity to obtain the balanced quantity includes:

[0022] Obtain the maximum value of the characteristic charge to obtain the maximum characteristic charge;

[0023] The difference between the maximum characteristic charge and the characteristic charge is calculated to obtain the balanced charge.

[0024] According to other embodiments of the energy balancing method of the present invention, the relational value table includes a first-order discharge relational value table and a second-order discharge relational value table. The first-order discharge relational value table is constructed based on paired data of the first-order discharge voltage data and time, and the second-order discharge relational value table is constructed based on paired data of the second-order discharge voltage data and time. The step of performing inflection point lookup on the differential voltage data according to the pre-constructed relational value table to obtain characteristic inflection points further includes:

[0025] The first-order discharge voltage data at the current moment is obtained from the first-order discharge relationship value table to obtain the first-order discharge target value.

[0026] The second-order discharge voltage data at the current moment is obtained according to the second-order discharge relationship value table to obtain the second-order discharge target value;

[0027] If the first-order discharge target value is less than the preset first-order discharge voltage threshold, and the second-order discharge target value is greater than the preset second-order discharge voltage threshold, the current point is taken as the feature inflection point.

[0028] According to other embodiments of the energy balancing method of the present invention, the step of performing balancing calculations based on the target characteristic quantity and the characteristic quantity to obtain the balanced quantity further includes:

[0029] Obtain the minimum value of the characteristic charge to obtain the minimum characteristic charge;

[0030] The minimum characteristic charge is subtracted from the characteristic charge to obtain the balanced charge.

[0031] According to other embodiments of the energy balancing method of the present invention, before obtaining the cell voltage of the battery cell at the current moment after a preset charging or discharging time to obtain cell voltage data, the method further includes:

[0032] Obtain environmental parameters of the power supply battery;

[0033] When the environmental parameters meet the preset environmental conditions, the current voltage of the battery cell is obtained after a preset charging or discharging time.

[0034] Secondly, one embodiment of the present invention provides an energy balancing device applied to a vehicle's power supply battery, comprising:

[0035] The single cell voltage acquisition module is used to acquire the single cell voltage at the current moment after a preset charging or discharging time, so as to obtain single cell voltage data.

[0036] The differential voltage calculation module is used to perform differential calculations on the individual unit voltage data if the individual unit voltage data is within a preset individual unit voltage range, so as to obtain differential voltage data.

[0037] 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.

[0038] 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.

[0039] The balanced power calculation module is used to perform balanced calculations based on the target characteristic power and the characteristic power to obtain the balanced power; wherein, the target characteristic power includes the maximum value or the minimum value of the characteristic power.

[0040] An energy balancing module is used to balance the energy of the power supply battery based on the balanced charge level.

[0041] The energy balancing device of this invention has at least the following beneficial effects: After a preset charging or discharging time for each battery cell, the cell voltage acquisition module acquires the cell voltage of each battery cell at the current moment in real time to obtain cell voltage data. The differential voltage calculation module compares the cell voltage data with a preset cell voltage range. If the cell voltage data is within the preset cell voltage range, the differential voltage data of each battery cell is calculated to obtain the differential voltage data of each battery cell. The inflection point search module pairs the differential voltage data with time to obtain paired data. Based on the paired data, a relational value table corresponding to each battery cell is constructed. The inflection point of the differential voltage data is found based on the relational value table to obtain the characteristic inflection point corresponding to each battery cell. The characteristic charge acquisition module acquires the charge of the battery cell corresponding to the characteristic inflection point to obtain the characteristic charge of each battery cell. The balancing charge calculation module acquires the target characteristic charge in the characteristic charge and performs balancing calculation based on the target characteristic charge and the characteristic charge to obtain the balanced charge of each battery cell. The balancing charge calculation module performs energy balancing on the entire power supply battery based on the balanced charge of each battery cell, enabling energy balancing of the power supply battery during charging or discharging.

[0042] Thirdly, one embodiment of the present invention provides an energy balancing device, comprising:

[0043] At least one processor, and,

[0044] A memory communicatively connected to the at least one processor; wherein,

[0045] 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.

[0046] 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.

[0047] 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

[0048] Figure 1 This is a schematic flowchart of a specific embodiment of the energy balancing method in this invention;

[0049] Figure 2 yes Figure 1 A schematic flowchart of a specific embodiment of step S102;

[0050] Figure 3 yes Figure 1 A schematic diagram of a specific embodiment of step S103;

[0051] Figure 4 yes Figure 1 A schematic diagram of a specific embodiment of step S105;

[0052] Figure 5 yes Figure 1 A schematic diagram of another specific embodiment of step S103;

[0053] Figure 6 yes Figure 1 A schematic diagram of another specific embodiment of step S105;

[0054] Figure 7 This is a schematic flowchart of another specific embodiment of the energy balancing method in this invention;

[0055] Figure 8 This is a schematic flowchart of another specific embodiment of the energy balancing method in this invention;

[0056] Figure 9 This is a block diagram of a specific embodiment of the energy balancing device in this invention.

[0057] Figure 10 This is a schematic diagram of a specific embodiment of the relational value table in this invention;

[0058] Figure 11 This is a schematic diagram of another specific embodiment of the relational value table in the present invention. Attached image description:

[0060] Modules 901, 902, 903, 904, 905, 906: Individual voltage acquisition module, 906, 907, 908, 909, 9000, 901, 9000, 9000, 901, 902, 903, 904, 905, 906: 9000, 9000, 900 Detailed Implementation

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] First, let's analyze the technical terms used in this application:

[0067] 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.

[0068] 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.

[0069] 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%.

[0070] Existing balancing methods for automotive power batteries, especially lithium iron phosphate batteries, include two approaches. One method determines the balancing amount of each cell based on the voltage difference at the end of charging. However, this method fails because the internal resistance of individual cells increases with age, and this increase varies across cells. For cells with low capacity but significantly increased internal resistance, their voltage may not be highest during the middle of charging but could be highest at the end. In such cases, the voltage difference-based balancing method becomes ineffective. Another approach is to calculate the balancing amount when the state of charge (SOC) is low, meaning the cell voltage is not in the OCV plateau region. In this case, the accurate SOC value is obtained by looking up the OCV value in a table, and then the balancing amount is determined based on the SOC difference. This method is highly accurate but requires the battery to be allowed to rest for an extended period.

[0071] 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 perform energy balancing on a power supply battery during charging or discharging.

[0072] 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 S106.

[0073] Step S101: Obtain the current cell voltage after a preset charging or discharging time for the battery cell to obtain cell voltage data.

[0074] Step S102: If the individual unit voltage data is within the preset individual unit voltage range, perform differential calculation on the individual unit voltage data to obtain differential voltage data;

[0075] 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.

[0076] Step S104: Obtain the battery cell's charge level based on the characteristic inflection point to obtain the characteristic charge level;

[0077] Step S105: Perform a balance calculation based on the target characteristic quantity and the characteristic quantity to obtain the balanced quantity; wherein, the target characteristic quantity includes the maximum value or the minimum value of the characteristic quantity.

[0078] Step S106: Perform energy balancing on the power supply battery based on the balancing charge level.

[0079] By executing steps S101 to S106, after each battery cell has been charged or discharged for a preset time, the current voltage of each battery cell is acquired in real time to obtain the battery cell voltage data. The battery cell voltage data is compared with a preset battery cell voltage range. If the battery cell voltage data is within the preset battery cell voltage range, the differential calculation is performed on the battery cell voltage data of each battery cell to obtain the differential voltage data of each battery cell. The differential voltage data is paired with time to obtain paired data. A relational value table corresponding to each battery cell is constructed based on the paired data. The inflection point of the differential voltage data is found based on the relational value table to obtain the characteristic inflection point corresponding to each battery cell. The charge of the battery cell corresponding to the characteristic inflection point is obtained to obtain the characteristic charge of each battery cell. The target characteristic charge is obtained from the characteristic charge. The equalization calculation is performed based on the target characteristic charge and the characteristic charge to obtain the equalized charge of each battery cell. The energy is balanced for the entire power supply battery based on the equalized charge of each battery cell. This allows for energy balancing of the power supply battery during charging or discharging.

[0080] It should be noted that the cell voltage is measured by the BMS battery system.

[0081] In step S101 of some embodiments, if each battery cell has been charged for a preset time, the power supply battery enters the charging state. If the power supply battery has been discharged for a preset time, the power supply battery enters the discharging state.

[0082] In step S102 of some embodiments, if the status information of the power supply battery is in a charging state, the preset single-cell voltage range includes less than 3.2V; if the status information of the power supply battery is in a discharging state, the preset single-cell voltage range includes greater than or equal to 3.2V.

[0083] Please refer to Figure 2 , Figure 2 A flowchart illustrating the energy balancing method in an embodiment of the present invention is shown. In some embodiments, the individual cell voltage data includes charging voltage data and discharging voltage data. The charging voltage data is the individual cell voltage data obtained during the charging process, and the discharging voltage data is the individual cell voltage data obtained during the discharging process. Step S102 includes, but is not limited to, steps S201 to S202.

[0084] Step S201: If the single-cell voltage data is the charging voltage data, perform second-order differential calculation on the charging voltage data to obtain second-order charging voltage data.

[0085] Step S202: If the single-unit voltage data is discharge voltage data, perform first-order differential calculation on the discharge voltage data to obtain first-order discharge voltage data, and perform second-order differential calculation on the discharge voltage data to obtain second-order discharge voltage data.

[0086] By executing steps S201 to S202, the state information of the power supply battery is obtained. If the power supply battery is in a charging state, the obtained single-cell voltage data is the charging voltage data, and the second-order derivative of the charging voltage data is performed to obtain the second-order charging voltage data. If the power supply battery is in a discharging state, the obtained single-cell voltage data is the discharging voltage data, and the first-order derivative of the discharging voltage data is performed to obtain the first-order discharging voltage data. The second-order derivative of the discharging voltage data is then performed to obtain the second-order discharging voltage data. This process allows for the acquisition of the required second-order charging voltage data, first-order discharging voltage data, and second-order discharging voltage data.

[0087] It should be noted that if the power supply battery is in a charging state, the second-order differential is performed on the charging voltage data of each individual battery cell to obtain the second-order charging voltage data of each individual battery cell. If the power supply battery is in a discharging state, the first-order differential is performed on the discharging voltage data of each individual battery cell to obtain the first-order discharging voltage data of each individual battery cell, and then the second-order differential is performed on the discharging voltage data of each individual battery cell to obtain the second-order discharging voltage data of each individual battery cell.

[0088] 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 second-order charging relational value table, which is constructed based on the pairing data of second-order charging voltage and time. Step S103 includes, but is not limited to, steps S301 to S302.

[0089] Step S301: Obtain the second-order charging voltage data at the current moment according to the second-order charging relationship value table, and obtain the second-order charging target value;

[0090] Step S302: If the second-order charging target value is less than the preset first charging voltage threshold and the second-order charging target value is greater than the preset second charging voltage threshold, the current point is taken as the feature inflection point.

[0091] By executing steps S301 to S302, if the power supply battery is in a charging state, the second-order charging voltage data and time are paired to obtain corresponding paired data, and a second-order charging relationship value table is constructed based on the corresponding paired data. The corresponding second-order charging voltage data is retrieved from the second-order charging relationship value table in real time based on the current moment to obtain the second-order charging target value. The second-order charging target value is compared with a preset first charging voltage threshold. If the second-order charging target value is less than the preset first charging voltage threshold, it is then compared with a preset second charging voltage threshold until the second-order charging target value at the current moment is greater than the preset second charging voltage threshold. The current moment is used as a feature inflection point to obtain the feature inflection points required during the charging process.

[0092] For example, let the current time be ti, i be a positive integer, and the second-order charging target value be V(ti). If the current time ti is the same as the current time t1, the second-order charging target value V(ti) is less than the preset first charging voltage threshold. Continue to compare and judge as time changes, until the current time ti is the same as the current time t2, and the second-order charging target value V(ti) is greater than the preset second charging voltage threshold. Then the characteristic inflection point is the point corresponding to time t2.

[0093] It should be noted that if the power supply battery is in a charging state, the second-order charging voltage data and time of each battery cell are paired to construct a second-order charging relationship value table for each battery cell. The corresponding feature inflection point is then searched based on this table until the feature inflection point for each battery cell is obtained. If the feature inflection point for each battery cell is not found, 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 for each battery cell is found.

[0094] Specifically, the current charging time is obtained, and the time is paired with the corresponding second-order charging voltage data to obtain corresponding paired data. The second-order charging 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 corresponding paired data to construct a second-order charging relationship value table. The plotted curve is detailed in [reference needed]. Figure 10 , Figure 10 These are the first-order and second-order differential curves of the battery when it is in a charging state.

[0095] In step S302 of some embodiments, the preset first charging voltage threshold is preferably -20. This preset first charging voltage threshold is selected based on the value of a point near the feature inflection point, and can be selected according to actual conditions. This application does not specifically limit the preset first charging voltage threshold. The preset second charging voltage threshold is preferably -2. This preset second charging voltage threshold is selected based on the value of a point near the feature inflection point, and can be selected according to actual conditions. This application does not specifically limit the preset second charging voltage threshold.

[0096] In step S104 of some embodiments, the power value corresponding to the characteristic inflection point of each battery cell is obtained to obtain the characteristic power value corresponding to each battery cell.

[0097] If the power supply battery is in a charging state, a first variable is preset. This first variable is used to statistically analyze the amount of electricity charged into the battery after charging begins, and the amount of electricity changes over time. A first array variable is also preset, with the array length set to the number of battery cells. This first array variable is used to store the amount of electricity charged into the battery when each battery cell reaches its respective characteristic inflection point, i.e., the characteristic electricity level, for convenient subsequent calculations using the characteristic electricity level. Specifically, when a battery cell is at a characteristic inflection point, the corresponding electricity level is retrieved from the first variable and stored in the first array variable to obtain the characteristic electricity level of that battery cell.

[0098] 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 S105 includes, but is not limited to, steps S401 to S402.

[0099] Step S401: Obtain the maximum value of the characteristic charge to obtain the maximum characteristic charge;

[0100] Step S402: Calculate the difference between the maximum characteristic charge and the characteristic charge to obtain the balanced charge.

[0101] By executing steps S401 to S402, if the power supply battery is in a charging state, and after each battery cell reaches its characteristic inflection point, the characteristic charge of each battery cell is compared to obtain the maximum value among the characteristic charges. The maximum characteristic charge is obtained by subtracting the characteristic charge of each battery cell from the maximum characteristic charge in turn to calculate the balanced charge of each battery cell, thus obtaining the balanced charge required during the charging process.

[0102] It should be noted that a second array variable is preset, which is used to store the balanced charge of each battery cell when it is charging.

[0103] For example, after the battery charging begins, a first variable A is preset to record the amount of electricity discharged, and this amount changes over time. A first array variable B is preset to record the amount of electricity in first variable A corresponding to each battery cell when it reaches its own characteristic inflection point. After each battery cell has reached its characteristic inflection point, the maximum value of first array variable B is obtained, reaching the maximum characteristic electricity. The values ​​of first array variable B are then subtracted from the maximum characteristic electricity to obtain the balanced electricity for each battery cell. A second array variable C is preset to record the balanced electricity for each battery cell.

[0104] Please refer to Figure 5 , Figure 5A 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 discharge relational value table and a second-order discharge relational value table. The first-order discharge relational value table is constructed based on the paired data of first-order discharge voltage data and time, and the second-order discharge relational value table is constructed based on the paired data of second-order discharge voltage data and time. Step S103 also includes, but is not limited to, steps S501 to S503.

[0105] Step S501: Obtain the first-order discharge voltage data at the current moment according to the first-order discharge relationship value table, and obtain the first-order discharge target value;

[0106] Step S502: Obtain the second-order discharge voltage data at the current moment according to the second-order discharge relationship value table, and obtain the second-order discharge target value;

[0107] Step S503: If the first-order discharge target value is less than the preset first-order discharge voltage threshold and the second-order discharge target value is greater than the preset second-order discharge voltage threshold, the current point is taken as the feature inflection point.

[0108] By executing steps S501 to S503, if the power supply battery is in a discharging state, the first-order discharge voltage data and time are paired to obtain corresponding paired data, and a first-order discharge relationship value table is constructed based on the corresponding paired data. The second-order discharge voltage data and time are paired to obtain corresponding paired data, and a second-order discharge relationship value table is constructed based on the corresponding paired data. The corresponding first-order discharge voltage data is obtained from the first-order discharge relationship value table in real time based on the current time to obtain the first-order discharge target value. The corresponding second-order discharge voltage data is obtained from the second-order discharge relationship value table in real time based on the current time to obtain the second-order discharge target value. The first-order discharge target value is compared with a preset first-order discharge voltage threshold. If the first-order target voltage value is less than the preset first-order voltage threshold, the second-order discharge target value is then compared with a preset second-order discharge voltage threshold until the second-order discharge target value at the current time is greater than the preset second-order discharge voltage threshold. The current time point is used as a feature inflection point to obtain the feature inflection point required during the discharge process.

[0109] 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.

[0110] It should be noted that if the power supply battery is in a discharging state, the first-order discharge voltage data and time of each battery cell are paired to construct a first-order discharge relationship value table for each battery cell. Similarly, the second-order discharge voltage data and time of each battery cell are paired to construct a second-order discharge relationship value table for each battery cell. The corresponding feature inflection points are obtained based on the first-order and second-order discharge relationship value tables for each battery cell until the feature inflection point for each battery cell is found. If the feature inflection point for each battery cell is not found, the obtained feature inflection points are stored, and the process returns to step S501 to search for battery cells for which no feature inflection point has been obtained until the feature inflection point for each battery cell is found.

[0111] Specifically, the current discharge time is obtained, and the time is paired with the corresponding first-order discharge voltage data to obtain paired first-order data. The first-order discharge voltage data is used as the y-axis coefficient, and time as the x-axis coefficient. A curve is plotted based on the paired first-order data to construct a first-order discharge relationship value table. Similarly, the time and corresponding second-order discharge voltage data are paired to obtain paired second-order data. The second-order discharge voltage data is used as the y-axis coefficient, and time as the x-axis coefficient. A curve is plotted based on the paired second-order data to construct a second-order discharge relationship value table. The specific plotted curves are described in [reference needed]. Figure 11 , Figure 11 This includes the first-order and second-order differential curves when the battery is in a discharged state.

[0112] In step S503 of some embodiments, the preset first-order discharge voltage threshold is preferably -15 in this application. The preset first-order discharge voltage threshold is selected based on the value of a point located near the characteristic inflection point, and can be selected according to the actual situation. This application does not specifically limit the preset first-order discharge voltage threshold. The preset second-order discharge voltage threshold is preferably 0.2 in this application. The preset second-order discharge voltage threshold is selected based on the value of a point located near the characteristic inflection point, and can be selected according to the actual situation. This application does not specifically limit the preset second-order discharge voltage threshold.

[0113] In step S104 of some embodiments, if the power supply battery is in a discharging state, a second variable is preset. This second variable is used to statistically analyze the amount of electricity discharged by the battery after the start of discharge, and the amount of electricity changes over time. A third array variable is preset, with the array length set to the number of battery cells. This third array variable is used to store the amount of electricity discharged by each battery cell when it reaches its respective characteristic inflection point, i.e., the characteristic amount of electricity, to facilitate subsequent calculations using the characteristic amount of electricity. Specifically, when a battery cell is at a characteristic inflection point, the corresponding amount of electricity is obtained from the second variable and stored in the third array variable to obtain the characteristic amount of electricity for that battery cell.

[0114] 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 S105 may include, but is not limited to, steps S601 to S602.

[0115] Step S601: Obtain the minimum value of the characteristic charge to obtain the minimum characteristic charge;

[0116] Step S602: Subtract the minimum characteristic charge from the characteristic charge to obtain the balanced charge.

[0117] By executing steps S601 to S602, if the power supply battery is in a discharging state, and after each battery cell reaches its characteristic inflection point, the characteristic charge of each battery cell is compared to obtain the minimum value among the characteristic charges. The minimum characteristic charge is obtained by subtracting the minimum characteristic charge from the characteristic charge of each battery cell in turn to calculate the balanced charge of each battery cell, thus obtaining the balanced charge required during the discharge process.

[0118] It should be noted that a fourth array variable is preset, which is used to store the equalized charge of each battery cell during the discharge state.

[0119] For example, after the power supply battery begins discharging, a second variable D is preset to record the amount of electricity discharged, which changes over time. A third array variable E is preset to record the amount of electricity in the second variable D corresponding to each battery cell when it reaches its own characteristic inflection point. After each battery cell has reached its characteristic inflection point, the minimum value of the third array variable E is obtained, reaching the minimum characteristic electricity level. The values ​​of the third array variable E are then successively compared with the minimum characteristic electricity level to obtain the equilibrium electricity level corresponding to each battery cell. A third array variable F is preset to record the equilibrium electricity level corresponding to each battery cell.

[0120] In step S106 of some embodiments, a timer is set for each battery cell. While performing energy balancing on each battery cell of the power supply battery, each timer is started. The timer of each battery cell decreases the balancing time according to a preset decreasing duration, and after each decrease, the remaining balancing time is obtained. The remaining time is then judged. If the remaining time is zero, energy balancing is complete, and energy balancing of the power supply battery stops. If the remaining time is not zero, meaning the power supply battery is powered off but energy balancing still needs to be performed, the remaining time is stored. After the power supply battery is powered on, energy balancing is performed on the power supply battery based on the remaining time; that is, the remaining time is set as the balancing charge, and step S106 is repeated until energy balancing is complete. This allows energy balancing of the power supply battery during charging or discharging.

[0121] It should be noted that if the balanced power is less than the preset balanced power threshold, the balanced power will be set to 0. The preset balanced power threshold is preferably 1% in this application, but no specific limitation is made to the preset balanced power threshold in this application.

[0122] 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, the energy balancing method further includes, but is not limited to, steps S701 to S702.

[0123] Step S701: Obtain the environmental parameters of the power supply battery;

[0124] Step S702: When the environmental parameters meet the preset environmental conditions, obtain the current cell voltage after a preset charging or discharging time for the battery cell.

[0125] By executing steps S701 to S702, environmental parameters include the change in current of the power supply battery and the current temperature of the power supply battery. The change in current and the current temperature of the power supply battery are obtained respectively to obtain the current change value and the current temperature value. Preset environmental conditions include preset current change thresholds and preset temperature thresholds. The current change value is compared with the preset current change threshold, and the current temperature value is compared with the 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, the cell voltage of each battery cell is obtained in real time after a preset charging or discharging time for each battery cell. This improves the accuracy of the obtained balanced charge, thereby improving the accuracy of energy balancing of the power supply battery.

[0126] It should be noted that 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.

[0127] 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.

[0128] 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.

[0129] 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:

[0130] During the charging or discharging process of the power supply battery, the environmental parameters of the power supply battery are acquired in real time. If the environmental parameters meet the preset environmental conditions, it is determined whether the voltage of each battery cell meets the preset voltage conditions. If all battery cells meet the conditions, the corresponding derivative of the voltage data of each battery cell is calculated to obtain the differential voltage data. Based on the differential voltage data of each battery cell, the characteristic inflection point of each battery cell is obtained, and the characteristic charge of the characteristic inflection point is recorded. Based on the characteristic charge, the charge that needs to be balanced in each battery cell is calculated to obtain the balanced charge. Based on the balanced charge, the required balancing time is calculated. Energy balancing is performed on each battery cell according to the required balancing time, which enables energy balancing of the power supply battery during the charging or discharging process.

[0131] In addition, this application also discloses an energy balancing device, please refer to... Figure 9 , Figure 9This 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 implement 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 balanced charge calculation module 905, and an energy balancing module 906. The single-cell voltage acquisition module 901, the differential voltage calculation module 902, the inflection point search module 903, the characteristic charge acquisition module 904, the balanced charge calculation module 905, and the energy balancing module 906 are all communicatively connected.

[0132] The single-cell voltage acquisition module 901 acquires the current single-cell voltage after a preset charging or discharging time, thus obtaining single-cell voltage data. If the single-cell voltage data is within a preset single-cell voltage range, the differential voltage calculation module 902 performs differential calculations 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-built 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 single-cell battery based on the characteristic inflection points to obtain characteristic charge. The equalization charge calculation module 905 performs equalization calculations based on the target characteristic charge and the characteristic charge to obtain the equalization charge; wherein, the target characteristic charge includes the maximum or minimum value of the characteristic charge. The energy equalization module 906 performs energy equalization on the power supply battery based on the equalization charge.

[0133] After a preset charging or discharging time for each battery cell, the cell voltage acquisition module 901 acquires the current cell voltage of each battery cell in real time 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 range. If the cell voltage data is within the preset range, it performs differential calculations on the cell voltage data of each battery cell to obtain differential voltage data for each battery cell, and transmits the differential voltage data to the inflection point lookup module 903. The inflection point lookup module 903 pairs the differential voltage data with time to obtain paired data, constructs a relational value table for each battery cell based on the paired data, and looks up the inflection point of the differential voltage data according to the relational value table to obtain the characteristic inflection point for each battery cell, and transmits the characteristic inflection point to the characteristic charge acquisition module 904. The characteristic charge acquisition module 904 acquires the charge of the battery cell corresponding to the characteristic inflection point to obtain the characteristic charge of each battery cell, and transmits the characteristic charge to the equalization charge calculation module 905. The equalization power calculation module 905 acquires the target characteristic power from the characteristic power, performs equalization calculations based on the target characteristic power and the characteristic power to obtain the equalization power of each battery cell, and transmits the equalization power to the equalization power calculation module 906. The equalization power calculation module 906 performs energy equalization of the entire power supply battery based on the equalization power of each battery cell, enabling energy equalization of the power supply battery during charging or discharging.

[0134] 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 7 The steps S101 to S106, S201 and S202, S301 and S302, S401 and S402, S501 to S503, S601 and S602, and S701 and S702 in the energy balance method are not described in detail here.

[0135] 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 S106 Figure 2 Control method steps S201 and S202 Figure 3Control method steps S301 and S302 Figure 4 Control method steps S401 and S402 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 and S702 of the control method.

[0136] 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 S106 Figure 2 Control method steps S201 and S202 Figure 3 Control method steps S301 and S302 Figure 4 Control method steps S401 and S402 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 and S702 of the control method.

[0137] 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.

[0138] 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.

[0139] 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: Obtain the current cell voltage after a preset charging or discharging time for a single battery cell to obtain cell voltage data; If the individual unit voltage data is within a preset individual unit voltage range, perform differential calculation on the individual unit voltage data 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; The balanced electricity is obtained by performing a balancing calculation based on the target characteristic electricity and the characteristic electricity; wherein, the target characteristic electricity includes the maximum value or the minimum value of the characteristic electricity. The power supply battery is equilibrated based on the balanced charge level.

2. The energy balancing method according to claim 1, characterized in that, The individual cell voltage data includes charging voltage data and discharging voltage data. The charging voltage data is the individual cell voltage data obtained during the charging process, and the discharging voltage data is the individual cell voltage data obtained during the discharging process. The step of performing differential calculations on the individual cell voltage data to obtain differential voltage data includes: If the single-unit voltage data is the charging voltage data, perform second-order differential calculation on the charging voltage data to obtain second-order charging voltage data; If the single-cell voltage data is the discharge voltage data, perform a first-order differential calculation on the discharge voltage data to obtain first-order discharge voltage data, and perform a second-order differential calculation on the discharge voltage data to obtain second-order discharge voltage data.

3. The energy balancing method according to claim 2, characterized in that, The relational value table includes a second-order charging relational value table, which is constructed based on the paired data of the second-order charging voltage and time. 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 second-order charging voltage data at the current moment is obtained according to the second-order charging relationship value table to obtain the second-order charging target value; If the second-order charging target value is less than the preset first charging voltage threshold, the second-order charging target value is then compared with the preset second charging voltage threshold until the second-order charging target value at the current moment is greater than the preset second charging voltage threshold. The point at the current moment is then taken as the feature inflection point.

4. The energy balancing method according to claim 3, characterized in that, The step of performing a balance calculation based on the target characteristic quantity and the characteristic quantity to obtain the balanced quantity includes: Obtain the maximum value of the characteristic charge to obtain the maximum characteristic charge; The difference between the maximum characteristic charge and the characteristic charge is calculated to obtain the balanced charge.

5. The energy balancing method according to claim 2, characterized in that, The relational value table includes a first-order discharge relational value table and a second-order discharge relational value table. The first-order discharge relational value table is constructed based on the paired data of the first-order discharge voltage and time. The second-order discharge relational value table is constructed based on the paired data of the second-order discharge voltage and time. 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 also includes: The first-order discharge voltage data at the current moment is obtained from the first-order discharge relationship value table to obtain the first-order discharge target value. The second-order discharge voltage data at the current moment is obtained according to the second-order discharge relationship value table to obtain the second-order discharge target value; If the first-order discharge target value is less than the preset first-order discharge voltage threshold, the second-order discharge target value is then compared with the preset second-order discharge voltage threshold until the second-order discharge target value at the current moment is greater than the preset second-order discharge voltage threshold. The point at the current moment is then taken as the feature inflection point.

6. The energy balancing method according to claim 5, characterized in that, The step of performing an equalization calculation based on the target characteristic quantity and the characteristic quantity to obtain the equalized quantity further includes: Obtain the minimum value of the characteristic charge to obtain the minimum characteristic charge; The minimum characteristic charge is subtracted from the characteristic charge to obtain the balanced charge.

7. The energy balancing method according to any one of claims 1 to 6, characterized in that, Before obtaining the cell voltage data by acquiring the cell voltage at the current moment after a preset charging or discharging time, the method further includes: Obtain environmental parameters of the power supply battery; When the environmental parameters meet the preset environmental conditions, the current voltage of the battery cell is obtained after a preset charging or discharging time.

8. 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 at the current moment after a preset charging or discharging time, so as to obtain single cell voltage data. The differential voltage calculation module is used to perform differential calculations on the individual unit voltage data if the individual unit voltage data is within a preset individual unit voltage range, 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. The balanced power calculation module is used to perform balanced calculations based on the target characteristic power and the characteristic power to obtain the balanced power; wherein, the target characteristic power includes the maximum value or the minimum value of the characteristic power. An energy balancing module is used to balance the energy of the power supply battery based on the balanced charge level.

9. 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 7.

10. 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 7.

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