A temperature compensation method and device and a storage medium

Abstract

The application discloses a temperature compensation method and device and a storage medium. The method comprises the following steps: acquiring a monitoring parameter of a battery management system in real time; wherein the monitoring parameter comprises a real-time current and a real-time temperature; performing temperature correction on the real-time temperature according to a preset processing strategy, the real-time current, a pre-constructed steady-state temperature difference compensation table and cell characteristic data of the battery management system to obtain a corrected temperature; wherein the cell characteristic data comprises a current direction, SOH, impedance and a temperature value; performing calculation on the corrected temperature based on the processing strategy to obtain a target temperature, and taking the target temperature as a cell body temperature; the beneficial effect is that the application can reconstruct the real temperature of the cell body with high precision through multi-factor correction, and significantly reduce the temperature measurement error.

Description

Technical Field

[0001] This invention relates to the field of lithium battery technology, specifically to a temperature compensation method, device, and storage medium. Background Technology

[0002] Lithium-ion batteries, with their significant advantages such as high energy density, long cycle life, and low environmental pollution, have been widely used in various fields, including consumer electronics, new energy vehicles, and energy storage systems, becoming a core support for the development of the current new energy industry. The Battery Management System (BMS), as the core of battery safe operation, has one of its key functions being the accurate monitoring of battery temperature. This is because lithium-ion batteries are extremely sensitive to temperature: excessively high temperatures accelerate side reactions, leading to shorter lifespans and even the risk of thermal runaway; excessively low temperatures cause lithium plating, resulting in irreversible capacity decay; and excessive temperature differences between modules exacerbate the uniform degradation of individual battery cells. Furthermore, almost all BMS algorithms, such as SOC estimation and charging management algorithms, require temperature as input. If the temperature sensing deviation is too large, it will significantly affect the accuracy of various BMS algorithms, potentially leading to insufficient battery performance or, in severe cases, serious safety accidents due to delayed thermal runaway warnings. Therefore, obtaining the actual temperature of the battery cell is the cornerstone for BMS to formulate charging management strategies, thermal management strategies (such as cooling / heating start-stop), estimate state parameters (such as SOC and SOP), and provide safety warnings.

[0003] The current mainstream method for lithium battery temperature detection is to collect temperature signals using temperature sensors (such as NTC thermistors) and transmit them to the BMS for processing. However, due to limitations in cell expansion control, electrical insulation safety distances, module compactness, and the complexity of assembly processes, temperature sensors are often difficult to place directly on the hottest spots or surfaces of the cell. The common practice is to mount the temperature sensor on the PCB protection board. For large power batteries or energy storage systems, they are sometimes mounted on the high-voltage connection busbar, sampling harness bracket, or cooling pipes of the battery module (this temperature measurement condition, where the sensor is far from the cell, can be understood as a remote temperature measurement condition). This results in a discrepancy between the temperature value collected by the sensor and the actual temperature of the cell, mainly due to the following three reasons:

[0004] (1) From the perspective of material thermodynamic properties, there are significant differences between the battery cell and the PCM protection board, wires, etc. in terms of heat generation power per unit volume, mass, specific heat capacity, thermal conductivity, specific surface area, etc., which leads to differences in temperature rise under the same overcurrent conditions, and the greater the current, the greater this difference.

[0005] (2) There is a certain spatial distance between the sensor and the battery cell body. The air, insulating materials and structural components between the two will form thermal resistance. The heat conduction between the battery cell body and the sensor is lagging, which makes the temperature collected by the sensor unable to follow the temperature change of the battery cell body in real time. This lag is more obvious, especially in scenarios where the lithium battery charge and discharge rate is high and the temperature changes drastically.

[0006] (3) The sensor is susceptible to interference from external ambient temperature, equipment heat dissipation system and surrounding electronic components, which further amplifies the temperature measurement deviation, resulting in the collected temperature signal failing to accurately reflect the temperature state of the battery cell. In the era of slow charging, this temperature measurement error problem may not be prominent, but with the explosion of demand for fast charging and high-power discharge of lithium batteries, the charging and discharging current of lithium batteries is getting larger and larger, and the difference between the temperature of the battery cell and the temperature monitored by the sensor may reach tens of degrees. If it is not optimized and improved, it will seriously affect the normal operation of the BMS.

[0007] Among the existing solutions in the technical field, some optimize the position of the temperature sensor from a hardware structure perspective, making it as close as possible to the battery cell body; others attempt to correct the temperature values ​​collected by the sensor through related methods from an algorithmic perspective, in order to approximate the true temperature of the battery cell body. However, these existing technical methods all have obvious shortcomings and are difficult to meet the needs of accurate detection of the battery cell body temperature in practical engineering applications. Specific reasons include:

[0008] First, the sensor placement method is optimized. This method abandons surface-mount NTCs (bare chips integrated on the PCB) and instead uses leaded NTC thermistors (referred to as leaded NTCs) to collect temperature. The installation position of leaded NTCs is relatively more flexible, and they can be installed on the cell terminals, top edge packaging positions, or even the large surface of the cell by adhesive or dispensing. The temperature collected by this method is indeed closer to the actual temperature of the cell, but the drawbacks are also obvious. First, the process is more complex. Ordinary surface-mount NTCs can be fully automated because they are directly integrated on the PCB, while leaded NTCs are difficult to automate due to the soldering, encapsulation, and wire handling processes, requiring more manual or semi-automation. Second, the cost is also higher. Due to factors such as materials, labor, equipment, and higher defect rates, the cost of leaded NTCs is 5 to 10 times higher than that of surface-mount NTCs. Third, there are certain requirements for the physical space of the module system. In the field of consumer electronics (such as mobile phones and tablets), the space is very compact, making it difficult to place leaded NTCs.

[0009] Second, there is the fixed difference compensation method. This method obtains a fixed difference between the sensor temperature and the cell temperature through offline testing. In practical applications, this fixed difference is directly superimposed on the sensor temperature to achieve temperature compensation. However, this method assumes that the temperature difference between the sensor and the cell is always constant, ignoring the influence of factors such as the lithium battery charge / discharge rate, ambient temperature, and operating time on the temperature difference. In reality, the heating rate and heat conduction efficiency of the cell will change under different operating scenarios, and the temperature difference will fluctuate accordingly. Fixed difference compensation cannot adapt to this dynamic change, has extremely low compensation accuracy, and cannot effectively correct temperature measurement deviations.

[0010] Third, based on the electrothermal coupling physical model and combined with Kalman filtering, the cell temperature is estimated. This method starts from the most basic physical principles and considers the heat generation, heat dissipation and heat conduction of each device in detail. In principle, it can accurately calculate the cell temperature. However, its drawbacks are that the model is too complex, with too many model parameters, which need to be calibrated one by one, and its universality is poor. Once the battery model or system structure changes, the model needs to be corrected and the parameters need to be recalibrated. On the other hand, its computational load is large, which is difficult to meet the requirements of low computing power and high real-time in embedded applications, and it is not suitable for large-scale engineering applications. Summary of the Invention

[0011] In view of the technical defects mentioned in the background art, the purpose of the embodiments of the present invention is to provide a temperature compensation method, device and storage medium, which aims to at least solve one of the technical problems in the related art to a certain extent.

[0012] To achieve the above objectives, in a first aspect, embodiments of the present invention provide a temperature compensation method, the method comprising:

[0013] Real-time acquisition of monitoring parameters of the battery management system; wherein, the monitoring parameters include real-time current and real-time temperature;

[0014] The real-time temperature is corrected according to the preset processing strategy, real-time current, pre-constructed steady-state temperature difference compensation table, and cell characterization data of the battery management system to obtain the corrected temperature; wherein, the cell characterization data includes current direction, SOH, impedance, and temperature value.

[0015] The target temperature is calculated based on the processing strategy and used as the cell body temperature.

[0016] As a specific implementation of this application, the step of correcting the real-time temperature based on a preset processing strategy, real-time current, a pre-constructed steady-state temperature difference compensation table, and cell characterization data from the battery management system to obtain a corrected temperature specifically includes:

[0017] The real-time current is calculated and processed according to a preset processing strategy to obtain the average current at the current moment.

[0018] The average current is combined with a pre-constructed steady-state temperature difference compensation table to interpolate and obtain the steady-state temperature difference value corresponding to the current average current, which is then used as the first-level temperature compensation value. The steady-state temperature difference compensation table is obtained by offline testing and calibration of the lithium battery under discharge / charge conditions.

[0019] Based on the cell characterization data, determine whether the first-level temperature compensation value needs to be corrected; if so, correct the first-level temperature compensation value to obtain the corresponding second-level temperature compensation value.

[0020] The corresponding corrected temperature is obtained based on the secondary temperature compensation value and the real-time temperature.

[0021] As a preferred embodiment of this application, the method further includes:

[0022] If the difference between the cell body temperature and the collected temperature exceeds a threshold, the cell body temperature will be corrected again.

[0023] As a specific implementation of this application, the temperature of the battery cell body is further corrected, specifically as follows:

[0024] The sum of the collected temperature and the threshold value is determined as the corrected cell body temperature.

[0025] As one specific implementation of this application, the processing strategy adopts the exponential moving average method.

[0026] As a specific implementation of this application, determining whether the primary temperature compensation value needs to be corrected based on the cell characterization data specifically includes:

[0027] Based on the current direction, determine whether the current state differs from the state obtained from the steady-state temperature difference compensation table. If so, use a preset direction correction coefficient k_I for correction. The current state includes the discharge / charge state of the lithium battery.

[0028] The aging state of the lithium battery is determined based on the SOH and impedance, and the current aging correction coefficient k_aging_now is obtained by interpolation from the pre-built aging state and correction data table according to the current aging state.

[0029] Based on the temperature value and temperature threshold, it is determined whether it is a low-temperature scenario. If so, the current low-temperature correction coefficient k_T is obtained by interpolation from the pre-built low-temperature correction data table according to the current temperature.

[0030] As a specific implementation of this application, the primary temperature compensation value is corrected to obtain the corresponding secondary temperature compensation value, calculated using the following formula:

[0031] dT2(t)=dT1(t)*k_I*k_aging_now*k_T;

[0032] Where dT2(t) is the second-level temperature compensation value, dT1(t) is the first-level temperature compensation value, k_I is the direction correction coefficient, k_aging_now is the current aging correction coefficient, and k_T is the current low-temperature correction coefficient.

[0033] Secondly, embodiments of the present invention also provide a temperature compensation device, the device comprising:

[0034] The acquisition module is used to acquire monitoring parameters of the battery management system in real time; wherein, the monitoring parameters include real-time current and real-time temperature;

[0035] The processing module is used to perform temperature correction on the real-time temperature according to a preset processing strategy, real-time current, a pre-constructed steady-state temperature difference compensation table, and cell characterization data of the battery management system to obtain a corrected temperature; wherein, the cell characterization data includes current direction, SOH, impedance, and temperature value;

[0036] The compensation module is used to calculate the target temperature based on the processing strategy and use the target temperature as the cell body temperature.

[0037] Thirdly, the present invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements a temperature compensation method as described in the first aspect.

[0038] The technical solution provided by this invention can reconstruct the true temperature of the battery cell with high accuracy by performing steady-state temperature difference compensation, exponential moving average, and multi-factor fine correction under scenarios such as charging and discharging direction, battery aging state, and low-temperature environment, significantly reducing temperature measurement error. This solution does not rely on a complex electrothermal coupling physical model, requires fewer calibration parameters, and has good versatility for changes in battery model and system structure. Moreover, it has low computational load, is easy to implement in embedded BMS with low computing power and high real-time operation, and can cover the entire battery life cycle and various charging and discharging conditions, meeting the temperature accuracy requirements in engineering applications. Attached Figure Description

[0039] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below.

[0040] Figure 1 This is a flowchart of a temperature compensation method provided in an embodiment of the present invention;

[0041] Figure 2A This is a test current diagram of a 5Ah battery at 10°C provided in an embodiment of the present invention.

[0042] Figure 2B This is a comparison chart of battery temperatures obtained in different ways at 10°C for a 5Ah battery provided in an embodiment of the present invention.

[0043] Figure 2C This is a comparison chart of the temperature error after compensation and correction and the error without correction for a 5Ah battery at 10°C, provided in an embodiment of the present invention.

[0044] Figure 3A This is a test current diagram of a 5Ah battery at 25°C provided in an embodiment of the present invention.

[0045] Figure 3B This is a comparison chart of battery temperatures obtained in different ways at 25°C for a 5Ah battery provided in an embodiment of the present invention.

[0046] Figure 3C This is a comparison chart of the temperature error after compensation and correction and the error without correction for a 5Ah battery at 25°C, provided in an embodiment of the present invention.

[0047] Figure 4A This is a test current diagram of a 5Ah battery at 45°C provided in an embodiment of the present invention.

[0048] Figure 4B This is a comparison chart of battery temperatures obtained in different ways at 45°C for a 5Ah battery provided in an embodiment of the present invention.

[0049] Figure 4C This is a comparison chart of the temperature error after compensation and correction and the error without correction for a 5Ah battery at 45°C, provided in an embodiment of the present invention.

[0050] Figure 5 This is a schematic diagram of a temperature compensation device provided in an embodiment of the present invention. Detailed Implementation

[0051] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0053] Throughout this specification, references to "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the invention. Therefore, the phrases "in an embodiment," "in an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination.

[0054] It should be noted that, unless otherwise stated, the technical terms used in this embodiment have the common meaning as understood in the relevant technical field.

[0055] Please refer to Figure 1 This invention provides a temperature compensation method applied to a battery management system, the method comprising:

[0056] S101, acquire monitoring parameters of the battery management system in real time; wherein, the monitoring parameters include real-time current and real-time temperature;

[0057] S102, the real-time temperature is corrected according to the preset processing strategy, real-time current, pre-constructed steady-state temperature difference compensation table and cell characterization data of the battery management system to obtain the corrected temperature; wherein, the cell characterization data includes current direction, SOH, impedance and temperature value.

[0058] S103, the target temperature is calculated based on the processing strategy and used as the cell body temperature.

[0059] In this embodiment, the BMS acquires the current I(t) and temperature T(t) of the battery management system at time t in real time through a current sensor and a patch NTC.

[0060] The processing strategy described above employs the exponential moving average method. By introducing this method, the collected current and temperature are subjected to an exponential moving average, which effectively solves two core problems under non-steady-state conditions: first, the change in the temperature value collected by the surface mount NTC lags behind the change in current; second, the change in the cell body temperature lags behind the change in the NTC temperature. It should be noted that the above strategy is only an example and is not intended to limit the application of this method.

[0061] Specifically, step S102 includes:

[0062] The real-time current is calculated and processed according to a preset processing strategy to obtain the average current at the current moment.

[0063] The average current is combined with a pre-constructed steady-state temperature difference compensation table to interpolate and obtain the steady-state temperature difference value corresponding to the current average current, which is then used as the first-level temperature compensation value. The steady-state temperature difference compensation table is obtained by offline testing and calibration of the lithium battery under discharge / charge conditions.

[0064] Based on the cell characterization data, determine whether the first-level temperature compensation value needs to be corrected; if so, correct the first-level temperature compensation value to obtain the corresponding second-level temperature compensation value.

[0065] The corresponding corrected temperature is obtained based on the secondary temperature compensation value and the real-time temperature.

[0066] When applied, the average current I_mean(t) at time t is calculated in real time according to the exponential moving average method, that is, I_mean(t)=I_mean(t-1)*weight_I+abs(I(t))*(1-weight_I), where abs represents taking the absolute value. By default, the charging current is positive and the discharging current is negative; Weight_I is the weighting coefficient, which ranges from 0 to 1.

[0067] In this embodiment, the steady-state temperature difference compensation table stores the temperature difference value corresponding to a certain discharge / charge current under steady-state conditions. For example, when a constant charging current passes through the battery, when heat generation and heat dissipation reach equilibrium and the temperature at various points no longer rises and reaches a steady state, the difference between the temperature value collected by the patch NTC and the temperature of the battery cell body is measured. Therefore, this table needs to be obtained through offline testing and calibration.

[0068] Based on the established steady-state temperature difference compensation table, the temperature difference value corresponding to the current average current I_mean(t) is obtained by interpolation. This value is defined as the first-level temperature compensation value and represented by dT1(t).

[0069] Furthermore, considering the aging state of lithium batteries and the impact of temperature differences in low-temperature environments and discharge scenarios; in application, the cell characterization data sources include: the BMS acquiring corresponding current values ​​through current sensors, using the sign of the value as the current direction to determine the current charge / discharge state; the temperature obtained through surface-mount NTC sensors to determine whether it is a low-temperature environment; and the SOH and impedance data acquired by existing BMS systems to determine the aging state; specifically including:

[0070] Based on the current direction, determine whether the current state differs from the state obtained from the steady-state temperature difference compensation table. If so, use a preset direction correction coefficient k_I for correction. The current state includes the discharge / charge state of the lithium battery.

[0071] The aging state of the lithium battery is determined based on the SOH and impedance, and the current aging correction coefficient k_aging_now is obtained by interpolation from the pre-built aging state and correction data table according to the current aging state.

[0072] Based on the temperature value and temperature threshold, it is determined whether it is a low-temperature scenario. If so, the current low-temperature correction coefficient k_T is obtained by interpolation from the pre-built low-temperature correction data table according to the current temperature.

[0073] Specifically, since the temperature rise of lithium batteries will be different when they are charged and discharged at the same current, and if the steady-state temperature difference compensation table is obtained under charging conditions, it needs to be corrected under discharging conditions. Here, a directional correction coefficient k_I is used to achieve this, and its value ranges from 0 to 1. Similarly, if the steady-state temperature difference compensation table is obtained under discharging conditions, it needs to be corrected during charging.

[0074] That is, if the steady-state temperature difference compensation table is obtained based on the charging process, then k_I takes the value of 0 to 1 during the discharging process; if the steady-state temperature difference compensation table is obtained based on the discharging process, then k_I takes the value of 0.5 to 2 during the charging process; the specific value of k_I is calculated by simultaneously conducting charging and discharging tests in the laboratory calibration test, and obtaining the steady-state temperature difference compensation table under the charging and discharging conditions respectively.

[0075] As lithium batteries age, their impedance and heat generation characteristics change accordingly, and the steady-state temperature difference also changes. Therefore, a correction is needed, which is achieved using an aging correction coefficient k_aging. k_aging is not a constant value; it varies with the aging state (SOH, impedance). Therefore, it is necessary to conduct aging tests on lithium batteries in the laboratory beforehand to obtain cells in different aging states, test the corresponding battery health state (SOH), impedance, and aging correction coefficient k_aging, and establish a two-dimensional data table of aging state and k_aging (i.e., the aging state and correction data table mentioned above). The value of k_aging ranges from 0 to 2 and varies with the aging state. In actual use, based on the current aging state of the battery, the current aging correction coefficient k_aging_now is obtained by querying this two-dimensional data table and interpolating.

[0076] A two-dimensional data table is created to store the aging correction coefficients corresponding to different SOH / impedance. In actual battery use, the two-dimensional data table can be interpolated according to the current aging state (SOH / impedance) of the battery to obtain the current aging correction coefficient.

[0077] At low temperatures, lithium batteries exhibit very high impedance, and their heat generation characteristics differ significantly from those at normal and high temperatures, which also affects the steady-state temperature difference. Therefore, a certain correction is required, which is achieved using a low-temperature correction coefficient k_T, with a value ranging from 0 to 2. To obtain k_T, a steady-state temperature difference compensation table needs to be calibrated in the laboratory under different low-temperature environments (e.g., -20 / -10 / 0 / 10 / 20℃). Then, k_T at different temperatures is calculated, and a one-dimensional data table (i.e., the low-temperature correction data table mentioned above) is established to store k_T at different temperatures. When the battery is actually in use, the current temperature of the battery (which can be approximated by the temperature value reconstructed from the previous second) can be used to interpolate the above one-dimensional data table to obtain the current low-temperature correction coefficient.

[0078] Since lithium batteries often experience aging changes in practical applications, including at least one of the following scenarios: low-temperature environments and discharge, the primary temperature compensation value needs to be corrected to obtain the corresponding secondary temperature compensation value. This is calculated using the following formula:

[0079] dT2(t)=dT1(t)*k_I*k_aging_now*k_T;

[0080] Where dT2(t) is the second-level temperature compensation value, dT1(t) is the first-level temperature compensation value, k_I is the direction correction coefficient, k_aging_now is the current aging correction coefficient, and k_T is the current low-temperature correction coefficient;

[0081] Then, the temperature T(t) collected by the patch NTC is compensated to obtain the corrected temperature T_cps(t), that is, T_cps(t)=T(t)-dT2(t);

[0082] Finally, the exponential moving average method is used again to average the compensated corrected temperature T_cps(t) as the final cell body temperature T_cell(t), i.e., T_cell(t) = T_cell(t-1)*weight_T + T_cps(t)*(1-weight_T); where T_cps(t) is the corrected temperature and Weight_T is the weighting coefficient, with a value range of 0~1.

[0083] Furthermore, to make the obtained data more reasonable, another embodiment, based on the above technical solution, further includes the following:

[0084] If the difference between the cell body temperature and the collected temperature exceeds a threshold, the cell body temperature will be further corrected, specifically as follows:

[0085] The sum of the collected temperature and the threshold value is determined as the corrected cell body temperature.

[0086] That is, if T_cell(t)>T(t)+T_thd, then let T_cell(t)=T(t)+T_thd; where T_cell(t) represents the final cell body temperature, T(t) represents the sampling temperature of the surface mount NTC, and T_thd represents the threshold value.

[0087] To more intuitively demonstrate the effectiveness of this technical solution, a 5Ah pouch battery was tested and verified. It was charged and discharged at various currents at 10 / 25 / 45℃, and the cell surface temperature was collected as the actual cell temperature. The results are as follows: Figures 2A to 4C As shown.

[0088] like Figures 2A to 2C As shown, the verification test of a 5Ah battery at 10℃: Figure 2A For testing current; Figure 2B Battery temperatures obtained in different ways (represented by NTC acquisition values, actual measured values ​​from temperature sensing lines, and compensation / correction values ​​from this invention); Figure 2C This invention provides a comparison between the corrected temperature error and the uncorrected error.

[0089] like Figures 3A to 3C As shown, the verification test of a 5Ah battery at 25℃: Figure 3A I'm testing the current; Figure 3B Battery temperatures obtained in different ways (represented by NTC acquisition values, actual measured values ​​from temperature sensing lines, and compensation / correction values ​​from this invention); Figure 3C This invention provides a comparison between the corrected temperature error and the uncorrected error.

[0090] like Figures 4A to 4C As shown, the verification test of a 5Ah battery at 45℃: Figure 4A For testing current; Figure 4B Battery temperatures obtained in different ways (represented by NTC acquisition values, actual measured values ​​from temperature sensing lines, and compensation / correction values ​​from this invention); Figure 4C This invention provides a comparison between the corrected temperature error and the uncorrected error.

[0091] The above verification shows that the cell temperature obtained by this technical solution has a maximum error of less than ±2℃ compared with the actual cell temperature, which is more than 80% lower than the error without compensation; the root mean square error is <0.5℃; and it meets the temperature accuracy requirements (±3℃) of the BMS algorithm and system.

[0092] The above solution eliminates the need for costly and complex leaded NTCs. Instead, it utilizes mature surface-mount NTCs for temperature acquisition. While maintaining low hardware costs, simple processes, and fully automated production capabilities without additional physical space requirements, it achieves high-precision reconstruction of the cell's true temperature by performing steady-state temperature difference compensation, exponential moving average, and multi-factor fine-tuning based on charging / discharging direction, battery aging status, and low-temperature environments. This significantly reduces temperature measurement errors. Furthermore, the solution does not rely on complex electrothermal coupling physical models, requires fewer calibration parameters, and exhibits good versatility for variations in battery models and system structures. It also requires minimal computation, making it easy to implement in embedded BMS systems with low computational power and high real-time performance. Moreover, it covers the entire battery lifecycle and various charging / discharging conditions, meeting the temperature accuracy requirements of engineering applications.

[0093] Reference Figure 5 Based on the same inventive concept, embodiments of the present invention also provide a temperature compensation device, the device comprising:

[0094] The acquisition module is used to acquire monitoring parameters of the battery management system in real time; wherein, the monitoring parameters include real-time current and real-time temperature;

[0095] The processing module is used to perform temperature correction on the real-time temperature according to a preset processing strategy, real-time current, a pre-constructed steady-state temperature difference compensation table, and cell characterization data of the battery management system to obtain a corrected temperature; wherein, the cell characterization data includes current direction, SOH, impedance, and temperature value;

[0096] The compensation module is used to calculate the target temperature based on the processing strategy and use the target temperature as the cell body temperature.

[0097] The step of correcting the real-time temperature based on a preset processing strategy, real-time current, a pre-constructed steady-state temperature difference compensation table, and cell characterization data from the battery management system to obtain the corrected temperature specifically includes:

[0098] The real-time current is calculated and processed according to a preset processing strategy to obtain the average current at the current moment.

[0099] The average current is combined with a pre-constructed steady-state temperature difference compensation table to interpolate and obtain the steady-state temperature difference value corresponding to the current average current, which is then used as the first-level temperature compensation value. The steady-state temperature difference compensation table is obtained by offline testing and calibration of the lithium battery under discharge / charge conditions.

[0100] Based on the cell characterization data, determine whether the first-level temperature compensation value needs to be corrected; if so, correct the first-level temperature compensation value to obtain the corresponding second-level temperature compensation value.

[0101] The corresponding corrected temperature is obtained based on the secondary temperature compensation value and the real-time temperature.

[0102] Determining whether the primary temperature compensation value needs correction based on the cell characterization data specifically includes:

[0103] Based on the current direction, determine whether the current state differs from the state obtained from the steady-state temperature difference compensation table. If so, use a preset direction correction coefficient k_I for correction. The current state includes the discharge / charge state of the lithium battery.

[0104] The aging state of the lithium battery is determined based on the SOH and impedance, and the current aging correction coefficient k_aging_now is obtained by interpolation from the pre-built aging state and correction data table according to the current aging state.

[0105] Based on the temperature value and temperature threshold, it is determined whether it is a low-temperature scenario. If so, the current low-temperature correction coefficient k_T is obtained by interpolation from the pre-built low-temperature correction data table according to the current temperature.

[0106] The primary temperature compensation value is corrected to obtain the corresponding secondary temperature compensation value, calculated using the following formula:

[0107] dT2(t)=dT1(t)*k_I*k_aging_now*k_T;

[0108] Where dT2(t) is the second-level temperature compensation value, dT1(t) is the first-level temperature compensation value, k_I is the direction correction coefficient, k_aging_now is the current aging correction coefficient, and k_T is the current low-temperature correction coefficient.

[0109] Furthermore, the temperature compensation device further includes a correction module, which is configured to:

[0110] If the difference between the cell body temperature and the collected temperature exceeds a threshold, the cell body temperature will be further corrected, specifically as follows:

[0111] The sum of the collected temperature and the threshold value is determined as the corrected cell body temperature.

[0112] It should be noted that for a more detailed description of the working process of the device embodiments, please refer to the foregoing method embodiments section, which will not be repeated here.

[0113] The entire solution, through steady-state temperature difference compensation, exponential moving average, and multi-factor fine-tuning correction under scenarios such as charge / discharge direction, battery aging state, and low-temperature environment, can accurately reconstruct the true temperature of the battery cell and significantly reduce temperature measurement errors. This solution does not rely on complex electrothermal coupling physical models, requires fewer calibration parameters, and has good versatility for changes in battery models and system structures. Moreover, it has low computational load, is easy to implement in embedded BMS with low computing power and high real-time performance, and can cover the entire battery life cycle and various charge / discharge conditions, meeting the temperature accuracy requirements of engineering applications.

[0114] In this embodiment, a computer-readable storage medium is also provided, which stores a computer program that, when executed by a processor, causes the processor to perform the steps of a temperature compensation method as described in the method embodiment.

[0115] Specifically, the processor can be a Central Processing Unit (CPU), but it can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0116] The code of the computer program can be in the form of source code, object code, executable file, or some intermediate form.

[0117] Computer-readable storage media may include cache, high-speed random access memory (RAM), such as the common double data rate synchronous dynamic random access memory (DDR SDRAM), and may also include non-volatile memory (NVRAM), such as one or more read-only memory (ROM), disk storage devices, flash memory devices, or other non-volatile solid-state storage devices such as optical discs (CD-ROM, DVD-ROM), floppy disks, or data tapes.

[0118] In the embodiments provided in this application, it should be understood that the disclosed methods and apparatus can also be implemented in other ways. The method embodiments described above are merely illustrative. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than that shown in the figures. For example, two consecutive blocks may actually be executed substantially in parallel, or they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, and combinations of blocks in the block diagram and / or flowchart, can be implemented using dedicated hardware-based apparatus that performs the specified functions or actions, or can be implemented using a combination of dedicated hardware and computer instructions.

[0119] Furthermore, the functional modules in the various embodiments of this invention can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part. The integrated modules can be implemented in hardware or as software functional modules. When in use, each module will only collect and store user information with the user's full authorization and in compliance with relevant laws and regulations, protecting the security and privacy of user data and strictly prohibiting unauthorized access; data processing will be conducted within the scope stipulated by law and will not exceed the purpose and scope authorized by the user; at the same time, users have the rights to access, correct, delete, restrict, and refuse processing of their personal data; and must strictly comply with applicable laws and regulations and conduct compliance reviews.

[0120] If the aforementioned functions are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations. 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.

Claims

1. A temperature compensation method, characterized in that, The method includes: The battery management system acquires monitoring parameters in real time; wherein the monitoring parameters include real-time current and real-time temperature. The real-time temperature is corrected according to the preset processing strategy, real-time current, pre-constructed steady-state temperature difference compensation table, and cell characterization data of the battery management system to obtain the corrected temperature; wherein, the cell characterization data includes current direction, SOH, impedance, and temperature value. The target temperature is calculated based on the processing strategy and used as the cell body temperature.

2. The temperature compensation method as described in claim 1, characterized in that, The step of correcting the real-time temperature based on a preset processing strategy, real-time current, a pre-constructed steady-state temperature difference compensation table, and cell characterization data from the battery management system to obtain the corrected temperature specifically includes: The real-time current is calculated and processed according to a preset processing strategy to obtain the average current at the current moment. The average current is combined with a pre-constructed steady-state temperature difference compensation table to interpolate and obtain the steady-state temperature difference value corresponding to the current average current, which is then used as the first-level temperature compensation value. The steady-state temperature difference compensation table is obtained by offline testing and calibration of the lithium battery under discharge / charge conditions. Based on the cell characterization data, determine whether the first-level temperature compensation value needs to be corrected; if so, correct the first-level temperature compensation value to obtain the corresponding second-level temperature compensation value. The corresponding corrected temperature is obtained based on the secondary temperature compensation value and the real-time temperature.

3. The temperature compensation method as described in claim 2, characterized in that, The method further includes: If the difference between the cell body temperature and the collected temperature exceeds a threshold, the cell body temperature will be corrected again.

4. The temperature compensation method as described in claim 3, characterized in that, The temperature of the battery cell body is further corrected, specifically as follows: The sum of the collected temperature and the threshold value is determined as the corrected cell body temperature.

5. The temperature compensation method as described in claim 1, characterized in that, The processing strategy employs the exponential moving average method.

6. A temperature compensation method according to any one of claims 2 to 4, characterized in that, Determining whether the primary temperature compensation value needs correction based on the cell characterization data specifically includes: Based on the current direction, determine whether the current state differs from the state obtained from the steady-state temperature difference compensation table. If so, use a preset direction correction coefficient k_I for correction. The current state includes the discharge / charge state of the lithium battery. The aging state of the lithium battery is determined based on the SOH and impedance, and the current aging correction coefficient k_aging_now is obtained by interpolation from the pre-built aging state and correction data table according to the current aging state. Based on the temperature value and temperature threshold, it is determined whether it is a low-temperature scenario. If so, the current low-temperature correction coefficient k_T is obtained by interpolation from the pre-built low-temperature correction data table according to the current temperature.

7. A temperature compensation method as described in claim 6, characterized in that, The primary temperature compensation value is corrected to obtain the corresponding secondary temperature compensation value, calculated using the following formula: dT2(t)=dT1(t)*k_I*k_aging_now*k_T; Where dT2(t) is the second-level temperature compensation value, dT1(t) is the first-level temperature compensation value, k_I is the direction correction coefficient, k_aging_now is the current aging correction coefficient, and k_T is the current low-temperature correction coefficient.

8. A temperature compensation device, characterized in that, The device includes: The acquisition module is used to acquire monitoring parameters of the battery management system in real time; wherein, the monitoring parameters include real-time current and real-time temperature; The processing module is used to perform temperature correction on the real-time temperature according to a preset processing strategy, real-time current, a pre-constructed steady-state temperature difference compensation table, and cell characterization data of the battery management system to obtain a corrected temperature; wherein, the cell characterization data includes current direction, SOH, impedance, and temperature value; The compensation module is used to calculate the target temperature based on the processing strategy and use the target temperature as the cell body temperature.

9. A temperature compensation device as described in claim 8, characterized in that, It also includes a correction module, which is configured to: If the difference between the cell body temperature and the collected temperature exceeds a threshold, the cell body temperature will be corrected again.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1-7.

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