Battery discharge power determination method and system
By acquiring the battery's state of charge, temperature, and discharge power, and using a preset power mapping table and voltage adjustment algorithm, the battery's discharge power is dynamically adjusted. This solves the problem that traditional strategies cannot adapt to dynamic changes in the battery, and achieves precise control of battery output power and safety assurance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SUNWODA MOBILITY ENERGY TECHNOLOGY CO LTD
- Filing Date
- 2026-01-19
- Publication Date
- 2026-05-05
AI Technical Summary
Traditional power switching strategies cannot adapt to the dynamic changes in battery characteristics, resulting in deviations in the battery's output power and causing safety issues.
By acquiring the battery's current state of charge, temperature, and discharge power, the discharge power value is queried using a preset power mapping table, and the final discharge power is determined through integration and adjustment algorithms. Combined with battery voltage adjustment, the battery's discharge power is dynamically adjusted.
It effectively reduces the deviation of the battery's output power, ensures the safety of battery use, and avoids overheating, lifespan degradation, or safety risks caused by long-term overload output.
Smart Images
Figure CN121978552A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of battery management system technology, and in particular to a method and system for determining battery discharge power. Background Technology
[0002] As the core power source of electric vehicles, the power battery's power performance directly determines the vehicle's acceleration capability, range stability, and driving experience, making it a key component affecting the vehicle's core competitiveness.
[0003] The power switching strategy is the control logic and execution rules of the BMS (Battery Management System) to dynamically adjust the battery's output power or received power based on the real-time status of the power battery. Traditional power switching strategies generally rely on discrete power mapping tables to construct control logic. Although this mode has basic control capabilities in early applications, its fixed threshold cannot adapt to the dynamic characteristics of the battery, such as low-temperature polarization and increased internal resistance due to aging. This makes it easy for the battery's output power or received power to deviate, leading to safety issues. Summary of the Invention
[0004] To address the aforementioned technical problems, embodiments of the present invention provide a method and system for determining battery discharge power, thereby resolving the technical problem that existing power switching strategies cannot adapt to the dynamic characteristics of batteries, resulting in deviations in the battery's external output power.
[0005] A first aspect of the present invention provides a method for determining battery discharge power, the method comprising: Obtain the battery's current state of charge, current temperature, and first discharge power value; Based on the current state of charge and the current temperature, the corresponding discharge power value is retrieved from the preset power mapping table to obtain the second discharge power value. The first discharge power value and the second discharge power value are compared to obtain the first target discharge power value. The first discharge power value and the second discharge power value are integrated to obtain the superpower energy integral value. If the super-power energy integral value is greater than a preset threshold, the first target discharge power value is adjusted to obtain the second target discharge power value. The second target discharge power value is determined to be the final discharge power of the battery. If the value is less than or equal to the preset threshold, the first target discharge power value is determined to be the final discharge power of the battery.
[0006] In one possible implementation of the first aspect, obtaining the second discharge power value further includes: Get the current battery voltage; Determine whether the current battery voltage is less than the first preset voltage threshold. If it is less, adjust the second discharge power value according to the preset adjustment method to obtain the third discharge power value. The first discharge power value and the third discharge power value are compared to obtain the first target discharge power value. The first discharge power value and the third discharge power value are integrated to obtain the superpower energy integral value.
[0007] In one possible implementation of the first aspect, the second discharge power value is adjusted according to a preset adjustment method to obtain a third discharge power value, including: If the current battery voltage is less than the second preset voltage threshold, the second discharge power value is adjusted according to the first preset slope to obtain the third discharge power value. If the current battery voltage is greater than or equal to the second preset voltage threshold and less than the first preset voltage threshold, the second discharge power value is adjusted according to the second preset slope to obtain the third discharge power value, wherein the second preset voltage threshold is less than the first preset voltage threshold and the first preset slope is greater than the second preset slope.
[0008] In one possible implementation of the first aspect, comparing a first discharge power value and a second discharge power value to obtain a first target discharge power value includes: The minimum discharge power value between the first discharge power value and the second discharge power value is selected as the first target discharge power value.
[0009] In one possible implementation of the first aspect, the superpower energy integral value is obtained by integrating the first discharge power value and the second discharge power value, including: Calculate the difference between the first discharge power value and the second discharge power value to obtain the power difference; Integrating the power difference yields the superpower energy integral.
[0010] In one possible implementation of the first aspect, when querying the corresponding discharge power value in a preset power mapping table based on the current state of charge and the current temperature, the method further includes: If no corresponding discharge power value is found in the preset power mapping table based on the current state of charge and current temperature, then the current internal resistance value of the battery is obtained. Based on the current internal resistance value, the power is predicted to obtain the second discharge power value.
[0011] In one possible implementation of the first aspect, a second discharge power value is obtained by predicting the power based on the current internal resistance value, including: Based on the emergency derating factor and battery performance parameters, a power prediction model is constructed, wherein the expression of the power prediction model is: In the formula, This is the first initial power value. This is the open-circuit voltage of the battery. This is the battery's cutoff voltage. This represents the actual internal resistance of the battery. The current internal resistance value is input into the power prediction model to predict the power and obtain the second discharge power value.
[0012] In one possible implementation of the first aspect, the preset power mapping table is determined by dynamically calibrating the test battery, including: According to the preset calibration method, the test batteries at different states of charge under each temperature condition are discharged to obtain the discharge power corresponding to the test batteries at different states of charge under each temperature condition. An initial power mapping table is obtained by testing the discharge power of the battery at different states of charge values under various temperature conditions. The initial power mapping table is nonlinearly interpolated to obtain a preset power mapping table, wherein the preset calibration method includes: Temperature conditions are divided according to the discharge temperature range of the test battery, and multiple state of charge values are determined for each temperature condition. The discharge temperature range is determined according to the actual use scenario of the test battery. According to the first preset speed, the discharge power of the test battery under each temperature condition and at different state of charge values is gradually increased until the voltage of the test battery is less than or equal to the cutoff voltage. Then, according to the second preset speed, the discharge power of the test battery is gradually decreased until the voltage no longer changes with the decrease in discharge power. The discharge is then stopped, and the current discharge power of the test battery is recorded.
[0013] To address the same technical problem, a second aspect of the present invention provides a battery discharge power determination system, comprising: The first acquisition module is used to acquire the current state of charge value, current temperature and first discharge power value of the battery; The discharge power determination module is used to look up the corresponding discharge power value in a preset power mapping table based on the current state of charge value and the current temperature, and obtain the second discharge power value. The super-power energy integral value calculation module is used to compare the first discharge power value and the second discharge power value to obtain the first target discharge power value, and to integrate the first discharge power value and the second discharge power value to obtain the super-power energy integral value. The judgment module is used to determine whether the super-power energy integral value is greater than a preset threshold. If it is greater than the preset threshold, the first target discharge power value is adjusted to obtain the second target discharge power value, and the second target discharge power value is determined to be the final discharge power of the battery. If it is less than or equal to the preset threshold, the first target discharge power value is determined to be the final discharge power of the battery.
[0014] One possible implementation of the first aspect also includes: The second acquisition module is used to acquire the current battery voltage; The second judgment module is used to determine whether the current battery voltage is less than the first preset voltage threshold. If it is less, the second discharge power value is adjusted according to the preset adjustment method to obtain the third discharge power value. The calculation module is used to compare the first discharge power value and the third discharge power value to obtain the first target discharge power value, and to integrate the first discharge power value and the third discharge power value to obtain the superpower energy integral value.
[0015] The technical solution of this invention has the following advantages: The battery discharge power determination method provided in this embodiment of the invention obtains the current state of charge (SOC), current temperature, and a first discharge power value of the battery. First, based on the current SOC and current temperature, the corresponding discharge power value is looked up in a preset power mapping table to obtain a second discharge power value. Then, the first and second discharge power values are combined to calculate a first target discharge power value and an excess power energy integral value. Finally, the excess power energy integral value is compared with a preset threshold. Based on the comparison result, the first target discharge power is adjusted or not adjusted to obtain the final discharge power. This effectively reduces the deviation of the battery's external output power and ensures the safety of battery use. Attached Figure Description
[0016] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0017] Figure 1 This is a schematic flowchart of a method for determining battery discharge power in an embodiment of the present invention; Figure 2 This is a schematic flowchart of another method for determining battery discharge power in an embodiment of the present invention; Figure 3This is a schematic diagram of the preset power mapping table calibration method in the battery discharge power determination method of the present invention. Figure 4 This is a structural block diagram of the battery discharge power determination system in an embodiment of the present invention. Detailed Implementation
[0018] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0019] The battery discharge power determination method provided in this embodiment of the invention, such as... Figure 1 As shown, Figure 1 The flowchart for determining battery discharge power includes steps S101 to S104, and the specific steps are as follows: S101. Obtain the current state of charge, current temperature, and first discharge power value of the battery.
[0020] In this embodiment, the current state of charge (SOC) value refers to the percentage of the battery's remaining charge relative to its rated capacity, as collected in real time by the battery management system. The current temperature refers to the actual operating temperature of the battery, detected in real time by the battery management system. The first discharge power value refers to the power demand calculated by the vehicle controller based on the current vehicle operating conditions, which is then sent to the battery management system.
[0021] It should be noted that this embodiment is only for illustrating some electrical parameters that may be used in this application. However, in practical applications, there are usually more than three battery electrical parameters, such as current value, voltage value, and state of health value, and the corresponding parameters can be selected according to actual needs.
[0022] S102. Based on the current state of charge and the current temperature, look up the corresponding discharge power value in the preset power mapping table to obtain the second discharge power value.
[0023] In this embodiment, the preset power mapping table is determined through dynamic calibration of the test battery. The test battery is consistent with the battery model, rated capacity, and material system in the actual application scenario, ensuring the representativeness and universality of the calibration results. The preset power mapping table includes the mapping relationship between the current state of charge (SOC), current temperature, and discharge power value. For example, a discharge power value corresponds to a 1% SOC interval and a 1°C temperature interval as the smallest unit. This discharge power value is the maximum allowable discharge power value. The second discharge power value is the discharge power value corresponding to the current SOC and current temperature in the preset power mapping table. After obtaining the current SOC and current temperature, the corresponding maximum allowable discharge power value is looked up to obtain the second discharge power value.
[0024] In one embodiment, the preset power mapping table is determined by dynamically calibrating the test battery, including: According to the preset calibration method, the test batteries at different states of charge under each temperature condition are discharged to obtain the discharge power corresponding to the test batteries at different states of charge under each temperature condition. An initial power mapping table is obtained by testing the discharge power of the battery at different states of charge values under various temperature conditions. The initial power mapping table is nonlinearly interpolated to obtain a preset power mapping table, wherein the preset calibration method includes: Temperature conditions are divided according to the discharge temperature range of the test battery, and multiple state of charge values are determined for each temperature condition. The discharge temperature range is determined according to the actual use scenario of the test battery. The discharge power of the test battery is gradually increased at the first preset speed until the voltage of the test battery is less than or equal to the cutoff voltage. Then, the discharge power of the test battery is gradually decreased at the second preset speed until the voltage no longer changes with the decrease in discharge power. The discharge is then stopped, and the current discharge power of the test battery is recorded.
[0025] In this embodiment, the discharge power of the test battery under different state of charge values under each temperature condition is obtained according to the preset calibration method. That is, the initial power mapping table is obtained by taking the 1% state of charge value interval and the 1℃ temperature interval as the smallest unit to correspond to a discharge power value. Then, cubic spline interpolation or Bézier curve is used to fill the blank area of the initial power mapping table to obtain the preset power mapping table, avoiding the "step effect" of linear interpolation.
[0026] In this embodiment, each temperature condition refers to a range defined based on the discharge operating temperature of the test battery. This discharge operating temperature range is determined according to the actual application scenario of the test battery. For example, when the test battery is used in an electric vehicle, the temperature conditions are divided into 1°C intervals. For instance, if the discharge operating temperature range is 25°C to 50°C, this is further divided into 25°C, 26°C, ..., 50°C temperature conditions. Each temperature condition corresponds to multiple state of charge (SOC) values, such as 100%, 80%, 60%, and 40% SOC values. The preset calibration method involves first gradually increasing the discharge power of the test battery at different states of charge (SOC) values under each temperature condition at a first preset rate. For example, a test battery at 25°C and 100% SOC is discharged, and the battery voltage is monitored in real time as the discharge power increases. When the battery voltage falls below the cutoff voltage, the discharge power is gradually decreased at a second preset rate, and the corresponding SOC value is monitored in real time as the discharge power decreases. Discharge is stopped when the voltage stabilizes, i.e., when the voltage no longer changes with decreasing discharge power, and the discharge power at this point is recorded. This discharge power is the maximum stable discharge power of the test battery at this temperature and SOC value. This process is repeated to discharge test batteries at different SOC values under each temperature condition, determining the corresponding discharge power for each SOC value at each temperature condition.
[0027] After obtaining the preset power mapping table, it is stored in a differential encoding compression format, employing a base value, differential, and Huffman coding method to reduce the storage space occupied by the preset power mapping table while ensuring data integrity. First, the base power value is determined; this base power value is the power at 25°C when the test battery's state of charge is 100%. Then, a differential matrix is constructed, with the differences being... In the formula, For the index of the state of charge value, For temperature index, , , For the first The first state of charge value Discharge power values at various temperatures. This is the baseline power value. The difference matrix is compressed using Huffman coding, achieving a compression ratio greater than 70%.
[0028] It should be noted that the first preset speed, the second preset speed, and the cutoff voltage can be determined according to actual needs. For example, the first preset speed is preferably 0.05C / s, and the second preset speed is preferably 0.1C / s. In low-temperature environments, the second preset speed can be increased. For example, in low-temperature environments, the second preset speed can be set to 0.2C / s.
[0029] In one embodiment, when obtaining the second discharge power value, the method further includes: Get the current battery voltage; Determine whether the current battery voltage is less than the first preset voltage threshold. If it is less, adjust the second discharge power value according to the preset adjustment method to obtain the third discharge power value. The first discharge power value and the third discharge power value are compared to obtain the first target discharge power value. The first discharge power value and the third discharge power value are integrated to obtain the superpower energy integral value.
[0030] In this embodiment, the current battery voltage is the lowest voltage obtained by real-time detection of the battery. When the current battery voltage is detected to be lower than a first preset voltage threshold, the voltage is determined accordingly. Then, a dynamic derating command is triggered. The dynamic derating command is a control signal generated by the voltage follower protection module, used to reduce the battery's maximum allowable discharge power value according to a preset slope, to prevent the battery voltage from further dropping below the cutoff voltage. The third discharge power value is the power value obtained by adjusting the second discharge power value according to a preset slope after the dynamic derating command is triggered.
[0031] After obtaining the third discharge power value, the first target discharge power value and the super-power energy integral value are re-determined using the third discharge power value and the first discharge power value. The method for calculating the first target discharge power value and the super-power energy integral value using the third discharge power value and the first discharge power value is the same as the method in step S103, and will not be described again in this embodiment.
[0032] In one embodiment, adjusting the second discharge power value according to a preset adjustment method to obtain a third discharge power value includes: If the current battery voltage is less than the second preset voltage threshold, the second discharge power value is adjusted according to the first preset slope to obtain the third discharge power value. If the current battery voltage is greater than or equal to the second preset voltage threshold and less than the first preset voltage threshold, the second discharge power value is adjusted according to the second preset slope to obtain the third discharge power value, wherein the second preset voltage threshold is less than the first preset voltage threshold and the first preset slope is greater than the second preset slope.
[0033] In this embodiment, the dynamic derating command is implemented by adjusting the power change rate. The derating targets include the upper limit of power output (i.e., the second discharge power value), the torque request value, and the charging power. Specifically, if the second discharge power value needs to be drated, the derating slope is determined based on the current battery voltage value, thereby reducing the second discharge power value according to the determined slope. For example, if the current battery voltage is less than a second preset voltage threshold, the emergency derating mode is activated, that is, the second discharge power value is adjusted according to a first preset slope, which is -100kW / s. If the current battery voltage is greater than or equal to the second preset voltage threshold but less than the first preset voltage threshold, the normal derating mode is activated, that is, the second discharge power value is adjusted according to a second preset slope, which is -50kW / s. If the current battery voltage is greater than the first preset voltage threshold, the battery output power is allowed to rise freely, at which point the slope is 100kW / s.
[0034] It should be noted that the second preset voltage threshold is The expression for the slope in the dynamic debit instruction is: The output power is updated in real time according to the slope, and the formula for calculating the output power is: In the formula, To control the cycle duration, The power output at the current moment. This represents the power output at the previous moment.
[0035] Substituting the second discharge power value into the above formula, we can obtain: In the formula, To control the cycle duration, This is the third discharge power value. This is the second discharge power value.
[0036] If the derating target is the torque request value, the vehicle controller is notified via the CAN (Controller Area Network) bus to limit the drive torque output. If the derating target is the charging power, the regenerative braking power is limited during braking scenarios.
[0037] S103. Compare the first discharge power value and the second discharge power value to obtain the first target discharge power value. Integrate the first discharge power value and the second discharge power value to obtain the superpower energy integral value.
[0038] In one embodiment, comparing a first discharge power value and a second discharge power value to obtain a first target discharge power value includes: The minimum discharge power value between the first discharge power value and the second discharge power value is selected as the first target discharge power value.
[0039] In this embodiment, the first target discharge power value is determined by comparing the first discharge power value and the second discharge power value. For example, after the battery management system determines the second discharge power value based on the battery's current state of charge and current temperature, the minimum value between the first and second discharge power values is selected to obtain the first target discharge power value. The calculation formula is as follows: In the formula, The first discharge power, This is the second discharge power. This is the third discharge power.
[0040] After obtaining the first target discharge power value, a gradient constraint is applied to the first target discharge power value through a Butterworth second-order low-pass filter to ensure that the power change rate satisfies the following formula: In the formula, This represents the first target discharge power value.
[0041] The transfer function of the Butterworth second-order low-pass filter is: In the formula, For control signals.
[0042] In one embodiment, the super-power energy integral value is obtained by integrating the first discharge power value and the second discharge power value, including: Calculate the difference between the first discharge power value and the second discharge power value to obtain the power difference; Integrating the power difference yields the superpower energy integral.
[0043] In this embodiment, the excess power energy integral is the accumulated energy when the monitored power demand exceeds the maximum allowable power. Specifically, within a preset time window, the difference between the first and second discharge power values is calculated. If the difference is greater than 0 (i.e., the first discharge power value is greater than the second discharge power value), the excess power and duration are accumulated to obtain the excess power energy integral. If the difference is less than 0 (i.e., the first discharge power value is less than the second discharge power value), no energy is accumulated. The specific calculation formula for the excess power energy integral is as follows: In the formula, For superpower energy integration, The first discharge power, This is the second discharge power. The starting time for integration is . The end time of the integration is denoted as .
[0044] After calculating the super-power energy integral, the super-power energy integral is used as an auxiliary judgment criterion to adjust the first target discharge power value to obtain the final target discharge power value, thereby avoiding overheating, lifespan degradation or safety risks caused by long-term overload output of the battery.
[0045] S104. Determine whether the super-power energy integral value is greater than a preset threshold. If it is greater than the preset threshold, adjust the first target discharge power value to obtain the second target discharge power value. Determine the second target discharge power value as the final discharge power of the battery. If it is less than or equal to the preset threshold, determine the first target discharge power value as the final discharge power of the battery.
[0046] In this embodiment, the first target discharge power value is adjusted by using the super-power energy integral as an auxiliary judgment criterion. Specifically, it is determined whether the super-power energy integral value is greater than a preset threshold. If it is greater than the preset threshold, the first target discharge power value is forcibly adjusted to a second target discharge power value, and the second target discharge power value is determined to be the final discharge power of the battery. If the super-power energy integral is less than or equal to the preset threshold, the first target discharge power value is determined to be the final discharge power of the battery.
[0047] It should be noted that the second target discharge power is preferably 0.7 times the second discharge power value. (Preset threshold) It is obtained by combining the second discharge power value with a preset time window determined during the integration of super-functional quantities. The specific formula is as follows: In the formula, For the preset threshold, This is the second discharge power value. This is a preset time window.
[0048] In one embodiment, when querying the corresponding discharge power value in a preset power mapping table based on the current state of charge and the current temperature, the method further includes: If no corresponding discharge power value is found in the preset power mapping table based on the current state of charge and current temperature, then the current internal resistance value of the battery is obtained. Based on the current internal resistance value, the power is predicted to obtain the second discharge power value.
[0049] In this embodiment, when no corresponding discharge power value is found in the preset power mapping table based on the current state of charge and current temperature, i.e., when the preset power mapping table verification fails, the system switches to power prediction based on the equivalent circuit model. The process of verifying the preset power mapping table is as follows: traverse all points in the preset power mapping table and detect... Is it in When the detected discharge power value is outside the range, such as negative power or exceeding 350kW, the system switches to power prediction based on the equivalent circuit model. The verification method also includes: for a fixed temperature... Examine the power sequence with state of charge values from 0% to 100%. Is it less than or equal to? For fixed SOC Examine the power series with temperatures ranging from -30°C to 55°C. Is it less than or equal to? If it is not less than, the verification fails.
[0050] The verification method also includes checking whether the power value is 0 at the low temperature boundary (-35℃) and the high temperature boundary (60℃), and whether the power value at the state of charge value of 0% in the preset power mapping table is 0. If it is not 0, it indicates that the verification has failed, and a diagnostic fault code is sent to the battery management system via the CAN bus.
[0051] In one embodiment, a second discharge power value is obtained by predicting the power based on the current internal resistance value, including: Based on the emergency derating factor and battery performance parameters, a power prediction model is constructed, wherein the expression of the power prediction model is: In the formula, This is the first initial power value. This is the open-circuit voltage of the battery. This is the battery's cutoff voltage. This represents the actual internal resistance of the battery. The current internal resistance value is input into the power prediction model to predict the power and obtain the second discharge power value.
[0052] In this embodiment, the power prediction is switched to an equivalent circuit model to obtain the actual internal resistance of the battery. The actual internal resistance is then input into the power prediction expression to obtain the first initial power value. The power prediction expression is as follows: In the formula, This is the first initial power value. This represents the current internal resistance of the battery. The emergency reduction coefficient is set to a fixed value of 0.5. This is the open-circuit voltage of the battery. This is the battery's cutoff voltage.
[0053] The battery discharge power determination system provided in this embodiment of the invention, such as... Figure 4 As shown, Figure 4 The system block diagram for determining the battery discharge power of system 400 includes: The first acquisition module 401 is used to acquire the current state of charge value, current temperature and first discharge power value of the battery; The discharge power determination module 402 is used to look up the corresponding discharge power value in a preset power mapping table based on the current state of charge value and the current temperature to obtain the second discharge power value. The super-power energy integral value calculation module 403 is used to compare the first discharge power value and the second discharge power value to obtain the first target discharge power value, and to integrate the first discharge power value and the second discharge power value to obtain the super-power energy integral value. The judgment module 404 is used to determine whether the super-power energy integral value is greater than a preset threshold. If it is greater than the preset threshold, the first target discharge power value is adjusted to obtain the second target discharge power value, and the second target discharge power value is determined to be the final discharge power of the battery. If it is less than or equal to the preset threshold, the first target discharge power value is determined to be the final discharge power of the battery.
[0054] In one embodiment, it further includes: The second acquisition module is used to acquire the current battery voltage; The second judgment module is used to determine whether the current battery voltage is less than the first preset voltage threshold. If it is less, the second discharge power value is adjusted according to the preset adjustment method to obtain the third discharge power value. The calculation module is used to compare the first discharge power value and the third discharge power value to obtain the first target discharge power value, and to integrate the first discharge power value and the third discharge power value to obtain the superpower energy integral value.
[0055] The specific implementation of the battery discharge power determination system is basically the same as the specific embodiment of the battery discharge power determination method described above, and will not be repeated here.
[0056] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0057] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.
Claims
1. A method for determining battery discharge power, characterized in that, include: Obtain the battery's current state of charge, current temperature, and first discharge power value; Based on the current state of charge value and the current temperature, the corresponding discharge power value is queried in the preset power mapping table to obtain the second discharge power value; The first discharge power value and the second discharge power value are compared to obtain the first target discharge power value. The first discharge power value and the second discharge power value are integrated to obtain the superpower energy integral value. If the super-power energy integral value is greater than a preset threshold, the first target discharge power value is adjusted to obtain a second target discharge power value, and the second target discharge power value is determined to be the final discharge power of the battery. If the second target discharge power value is less than or equal to the preset threshold, the first target discharge power value is determined to be the final discharge power of the battery.
2. The method for determining battery discharge power as described in claim 1, characterized in that, When obtaining the second discharge power value, the method further includes: Obtain the current battery voltage of the battery; Determine whether the current battery voltage is less than a first preset voltage threshold. If it is less, adjust the second discharge power value according to a preset adjustment method to obtain a third discharge power value. The first discharge power value and the third discharge power value are compared to obtain the first target discharge power value. The first discharge power value and the third discharge power value are integrated to obtain the superpower energy integral value.
3. The method for determining battery discharge power as described in claim 2, characterized in that, The step of adjusting the second discharge power value according to a preset adjustment method to obtain the third discharge power value includes: If the current battery voltage is less than the second preset voltage threshold, the second discharge power value is adjusted according to the first preset slope to obtain the third discharge power value; If the current battery voltage is greater than or equal to the second preset voltage threshold and less than the first preset voltage threshold, the second discharge power value is adjusted according to the second preset slope to obtain a third discharge power value, wherein the second preset voltage threshold is less than the first preset voltage threshold and the first preset slope is greater than the second preset slope.
4. The method for determining battery discharge power as described in claim 1, characterized in that, The step of comparing the first discharge power value and the second discharge power value to obtain the first target discharge power value includes: The minimum discharge power value between the first discharge power value and the second discharge power value is selected as the first target discharge power value.
5. The method for determining battery discharge power as described in claim 1, characterized in that, The step of integrating the first discharge power value and the second discharge power value to obtain the super-power energy integral value includes: Calculate the difference between the first discharge power value and the second discharge power value to obtain the power difference; Integrating the power difference yields the superpower energy integral.
6. The method for determining battery discharge power as described in claim 1, characterized in that, When querying the corresponding discharge power value in a preset power mapping table based on the current state of charge value and the current temperature, the process further includes: If no corresponding discharge power value is found in the preset power mapping table based on the current state of charge value and the current temperature, then the current internal resistance value of the battery is obtained. The second discharge power value is obtained by predicting the power based on the current internal resistance value.
7. The method for determining battery discharge power as described in claim 6, characterized in that, The step of predicting the power based on the current internal resistance value to obtain the second discharge power value includes: Based on the emergency derating factor and the battery's performance parameters, a power prediction model is constructed, wherein the expression of the power prediction model is: In the formula, The first initial power value, The open-circuit voltage of the battery is [value missing]. This is the cutoff voltage of the battery. The actual internal resistance of the battery; The current internal resistance value is input into the power prediction model to perform power prediction, and the second discharge power value is obtained.
8. The method for determining battery discharge power as described in claim 1, characterized in that, The preset power mapping table is determined by dynamically calibrating the test battery, and includes: According to the preset calibration method, the test batteries at different states of charge under each temperature condition are discharged to obtain the discharge power corresponding to the test batteries at different states of charge under each temperature condition. Based on the test battery discharge power corresponding to different states of charge values under each of the aforementioned temperature conditions, an initial power mapping table is obtained. The initial power mapping table is nonlinearly interpolated to obtain a preset power mapping table, wherein the preset calibration method includes: The temperature conditions are divided according to the discharge temperature range of the test battery, and multiple state of charge values corresponding to each temperature condition are determined, wherein the discharge temperature range is determined according to the actual use scenario of the test battery. According to the first preset speed, the discharge power of the test battery under each temperature condition and at different state of charge values is gradually increased until the voltage of the test battery is less than or equal to the cutoff voltage. Then, according to the second preset speed, the discharge power of the test battery is gradually decreased until the voltage no longer changes with the decrease in discharge power. The discharge is then stopped, and the current discharge power of the test battery is recorded.
9. A battery discharge power determination system, characterized in that, include: The first acquisition module is used to acquire the current state of charge value, current temperature and first discharge power value of the battery; The discharge power determination module is used to look up the corresponding discharge power value in the preset power mapping table based on the current state of charge value and the current temperature to obtain the second discharge power value. The super-power energy integral value calculation module is used to compare the first discharge power value and the second discharge power value to obtain the first target discharge power value, and to integrate the first discharge power value and the second discharge power value to obtain the super-power energy integral value. The judgment module is used to determine whether the super-power energy integral value is greater than a preset threshold. If it is greater than the preset threshold, the first target discharge power value is adjusted to obtain a second target discharge power value, and the second target discharge power value is determined to be the final discharge power of the battery. If it is less than or equal to the preset threshold, the first target discharge power value is determined to be the final discharge power of the battery.
10. The battery discharge power determination system as described in claim 9, characterized in that, Also includes: The second acquisition module is used to acquire the current battery voltage of the battery; The second judgment module is used to determine whether the current battery voltage is less than the first preset voltage threshold. If it is less, the second discharge power value is adjusted according to the preset adjustment method to obtain the third discharge power value. The calculation module is used to compare the first discharge power value and the third discharge power value to obtain a first target discharge power value, and to integrate the first discharge power value and the third discharge power value to obtain an overpower energy integral value.