Power battery pack cell temperature online compensation method and device, vehicle and medium

Abstract

The invention relates to a power battery pack cell temperature online compensation method and device, a vehicle and a medium. Comprising the following steps: grouping a plurality of temperature sensor groups based on a plurality of temperature sensors of a current power battery pack; on the basis of the multiple temperature sensor groups and the current working condition of the current power battery pack, the temperature rise rate value of the compensation temperature of each temperature sensor group is obtained, and on the basis of the temperature rise rate value of the compensation temperature of each temperature sensor group, the compensation temperature value of each temperature sensor group is obtained; and based on the collected temperature value of each temperature sensor group and the compensation temperature value of each temperature sensor group, compensating the cell temperature of the current power battery pack to obtain an actual cell temperature array of the current power battery pack. Therefore, the real-time temperature compensation value of each temperature sensor can be calculated on line, the real temperature of the battery pack is further obtained, the problem that the battery cell temperature of the power battery pack is inaccurately estimated in the prior art is solved, and fine management of the battery pack is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power battery management, and in particular relates to a power battery pack cell temperature online compensation method and device, a vehicle and a medium. BACKGROUND

[0002] With the rapid development of new energy vehicles, as the core component of the new energy vehicles, the performance and safety of the power battery are crucial to the operation of the vehicle. The battery management system (BMS) is a key technology to ensure the safe operation of the battery, which can monitor and control the battery unit in real time, prevent overcharging and overdischarging, and prolong the service life of the battery. Among them, the accurate detection of battery temperature, voltage, current and other parameters is the basic function of the BMS, and the accurate measurement of the temperature is particularly important because it directly affects the power output, capacity estimation and fault diagnosis of the battery.

[0003] In the related art, the temperature sensor is usually arranged on the bus bar of the battery module where the cells are connected in series and in parallel, and is used to collect the battery temperature. However, due to the inconsistent current carrying capacity of the bus bar, especially during high current charging and discharging, the deviation between the temperature collected by the temperature sensor and the real temperature of the cell is particularly significant, which leads to the inability to accurately estimate the real temperature of the battery pack cell, and needs to be solved urgently. SUMMARY

[0004] The present application provides a power battery pack cell temperature online compensation method, device, vehicle and medium to solve the problem of inaccurate estimation of the power battery pack cell temperature in the prior art, realizes the fine management of the battery pack, and improves the accuracy of SOX state regulation.

[0005] To achieve the above purpose, the first aspect of the present application provides a power battery pack cell temperature online compensation method, comprising the following steps:

[0006] Determine a plurality of temperature sensors of a current power battery pack, and based on the plurality of temperature sensors, obtain a plurality of temperature sensor groups by grouping;

[0007] Determine the current working condition of the current power battery pack, based on the plurality of temperature sensor groups and the current working condition, obtain the temperature rise rate value of the compensation temperature of each temperature sensor group, and based on the temperature rise rate value of the compensation temperature of each temperature sensor group, obtain the compensation temperature value of each temperature sensor group;

[0008] Obtain the acquisition temperature value of each temperature sensor group, and based on the acquisition temperature value of each temperature sensor group and the compensation temperature value of each temperature sensor group, compensate the cell temperature of the current power battery pack to obtain the actual cell temperature array of the current power battery pack.

[0009] According to one embodiment of the present application, the current working condition is a preset charging working condition, and the obtaining of the temperature rise rate value of the compensation temperature of each temperature sensor group based on the multiple temperature sensor groups and the current working condition comprises:

[0010] determining a first calibration working condition test condition;

[0011] performing a first calibration working condition test based on the first calibration working condition test condition, and obtaining first thermocouple change data of a thermocouple arranged at a preset position of the current power battery pack, first change data of each temperature sensor group, and first current data;

[0012] fitting to obtain a first actual temperature rise rate of a cell temperature of the current power battery pack under the first calibration working condition test based on the first thermocouple change data and the first current data;

[0013] obtaining a first temperature rise rate of each temperature sensor group based on the first change data of each temperature sensor group, and obtaining a first temperature rise rate value of a compensation temperature of each temperature sensor group based on the first temperature rise rate of each temperature sensor group and the first actual temperature rise rate of the cell temperature.

[0014] According to one embodiment of the present application, the current working condition is a preset discharging working condition, and the obtaining of the temperature rise rate value of the compensation temperature of each temperature sensor group based on the multiple temperature sensor groups and the current working condition comprises:

[0015] determining a second calibration working condition test condition;

[0016] performing a second calibration working condition test based on the second calibration working condition test condition, and obtaining second thermocouple change data of a thermocouple arranged at a preset position of the current power battery pack, second change data of each temperature sensor group, and second current data;

[0017] fitting to obtain a second actual temperature rise rate of a cell temperature of the current power battery pack under the second calibration working condition test based on the second thermocouple change data and the second current data;

[0018] obtaining a second temperature rise rate of each temperature sensor group based on the second change data of each temperature sensor group, and obtaining a second temperature rise rate value of a compensation temperature of each temperature sensor group based on the second temperature rise rate of each temperature sensor group and the second actual temperature rise rate of the cell temperature.

[0019] According to one embodiment of the present application, the current working condition is a preset charging working condition, and the compensation temperature value of each temperature sensor group is obtained based on the temperature rise rate value of the compensation temperature of each temperature sensor group, including:

[0020] The first compensation temperature value of each temperature sensor group is obtained by respectively integrating the first temperature rise rate value of the compensation temperature of each temperature sensor group within a first preset time.

[0021] According to one embodiment of the present application, the current working condition is a preset discharging working condition, and the compensation temperature value of each temperature sensor group is obtained based on the temperature rise rate value of the compensation temperature of each temperature sensor group, including:

[0022] The second compensation temperature value of each temperature sensor group is obtained by respectively integrating the second temperature rise rate value of the compensation temperature of each temperature sensor group within a second preset time.

[0023] According to one embodiment of the present application, the actual cell temperature array of the current power battery pack is obtained by compensating the cell temperature of the current power battery pack based on the collected temperature value of each temperature sensor group and the compensation temperature value of each temperature sensor group, including:

[0024] The calculation result corresponding to each temperature sensor group is obtained by respectively performing difference calculation on the collected temperature value of each temperature sensor group and the compensation temperature value of the corresponding temperature sensor group.

[0025] The actual cell temperature array of the current power battery pack is obtained according to the calculation result corresponding to each temperature sensor group.

[0026] The power battery pack cell temperature online compensation method according to the embodiments of the present application obtains multiple temperature sensor groups by grouping based on multiple temperature sensors of the current power battery pack, obtains the temperature rise rate value of the compensation temperature of each temperature sensor group based on the multiple temperature sensor groups and the current working condition of the current power battery pack, obtains the compensation temperature value of each temperature sensor group based on the temperature rise rate value of the compensation temperature of each temperature sensor group, and compensates the cell temperature of the current power battery pack based on the collected temperature value of each temperature sensor group and the compensation temperature value of each temperature sensor group to obtain the actual cell temperature array of the current power battery pack. Thus, the real-time temperature compensation value of each temperature sensor can be calculated online, and the real temperature of the battery pack is obtained, thereby solving the problem of inaccurate estimation of the cell temperature of the power battery pack in the prior art, achieving fine management of the battery pack, and improving the accuracy of SOX state regulation.

[0027] To achieve the above object, the second aspect of the present application proposes a power battery pack cell temperature online compensation device, comprising:

[0028] A grouping module is configured to determine a plurality of temperature sensors of a current power battery pack, and group the plurality of temperature sensors into a plurality of temperature sensor groups based on the plurality of temperature sensors.

[0029] An obtaining module is configured to determine a current working condition of the current power battery pack, obtain a temperature rise rate value of a compensation temperature of each temperature sensor group based on the plurality of temperature sensor groups and the current working condition, and obtain a compensation temperature value of each temperature sensor group based on the temperature rise rate value of the compensation temperature of each temperature sensor group.

[0030] A compensation module is configured to obtain an acquisition temperature value of each temperature sensor group, and compensate a cell temperature of the current power battery pack based on the acquisition temperature value of each temperature sensor group and the compensation temperature value of each temperature sensor group, to obtain an actual cell temperature array of the current power battery pack.

[0031] According to an embodiment of the present application, the current working condition is a preset charging working condition, and the obtaining module is specifically configured to:

[0032] determine a first calibration working condition test condition;

[0033] perform a first calibration working condition test based on the first calibration working condition test condition, and obtain first thermocouple change data of a thermocouple arranged at a preset position of the current power battery pack, first change data of each temperature sensor group, and first current data;

[0034] fit to obtain a first actual temperature rise rate of the cell temperature of the current power battery pack under the first calibration working condition test based on the first thermocouple change data and the first current data;

[0035] obtain a first temperature rise rate of each temperature sensor group based on the first change data of each temperature sensor group, and obtain a first temperature rise rate value of the compensation temperature of each temperature sensor group based on the first temperature rise rate of each temperature sensor group and the first actual temperature rise rate of the cell temperature.

[0036] According to an embodiment of the present application, the current working condition is a preset discharging working condition, and the obtaining module is specifically configured to:

[0037] determine a second calibration working condition test condition;

[0038] perform a second calibration operating condition test based on the second calibration operating condition test condition, and obtain second thermocouple change data of a thermocouple arranged at a preset position of the current power battery pack, second change data of each of the temperature sensor groups, and second current data;

[0039] fit, based on the second thermocouple change data and the second current data, a second actual temperature rise rate of the cell temperature of the current power battery pack under the second calibration operating condition test;

[0040] obtain, based on the second change data of each of the temperature sensor groups, a second temperature rise rate of each of the temperature sensor groups, and obtain, based on the second temperature rise rate of each of the temperature sensor groups and the second actual temperature rise rate of the cell temperature, a second temperature rise rate value of a compensated temperature of each of the temperature sensor groups.

[0041] According to an embodiment of the present application, the current operating condition is a preset charging operating condition, and the obtaining module is specifically configured to:

[0042] integrate, respectively, the first temperature rise rate value of the compensated temperature of each of the temperature sensor groups in a first preset time, to obtain a first compensated temperature value of each of the temperature sensor groups.

[0043] According to an embodiment of the present application, the current operating condition is a preset discharging operating condition, and the obtaining module is specifically configured to:

[0044] integrate, respectively, the second temperature rise rate value of the compensated temperature of each of the temperature sensor groups in a second preset time, to obtain a second compensated temperature value of each of the temperature sensor groups.

[0045] According to an embodiment of the present application, the compensation module is specifically configured to:

[0046] perform difference calculation, respectively, on the collected temperature value of each of the temperature sensor groups and the compensated temperature value of the corresponding temperature sensor group, to obtain a corresponding calculation result of each of the temperature sensor groups;

[0047] obtain, based on the corresponding calculation result of each of the temperature sensor groups, an actual cell temperature array of the current power battery pack.

[0048] The power battery pack electric core temperature online compensation device provided by the embodiment of the application obtains multiple temperature sensor groups through multiple temperature sensors of the current power battery pack.

[0049] To achieve the above object, the third aspect of the present application provides a vehicle, comprising a memory, a processor and a computer program stored in the memory and executable on the processor, and the processor executes the program to implement the power battery pack electric core temperature online compensation method as described in the above embodiments.

[0050] To achieve the above object, the fourth aspect of the present application provides a computer readable storage medium having a computer program stored thereon, and the program is executed by a processor to implement the power battery pack electric core temperature online compensation method as described in the above embodiments.

[0051] Additional aspects and advantages of the present application will be made apparent by the following description and the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0052] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the accompanying drawings, in which:

[0053] Figure 1 A flow chart of a power battery pack electric core temperature online compensation method according to an embodiment of the present application;

[0054] Figure 2 A block schematic diagram of a power battery pack electric core temperature online compensation device according to an embodiment of the present application;

[0055] Figure 3 A structural schematic diagram of a vehicle according to an embodiment of the present application. DETAILED DESCRIPTION

[0056] Embodiments of the present application are described below in detail, examples of which are shown in the accompanying drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0057] A power battery pack cell temperature online compensation method, device, vehicle and medium are described below with reference to the accompanying drawings according to an embodiment of the present application.

[0058] Figure 1 A flowchart of the power battery pack cell temperature online compensation method according to an embodiment of the present application is shown in FIG. 1.

[0059] Before introducing the power battery pack cell temperature online compensation method according to an embodiment of the present application, a brief introduction of the related technical background is given.

[0060] In the related art, the temperature sensor in the battery module is arranged on the busbar connected in series and parallel with the cells, and the busbar is made of aluminum or copper. When there is no current passing through, the temperature collected at the position of the busbar is equivalent to the real temperature of the cells; when charging and discharging, the size of the current will cause the busbar to heat to different degrees, and the temperature actually collected by the temperature sensor is the sum of the real temperature of the cells and the heat generated by the busbar itself. Due to manufacturing process, safety reliability, cost and other reasons, the current-carrying capacity of the busbar in each battery pack is inconsistent. If the current-carrying capacity of the busbar is small, the deviation between the temperature collected by the temperature sensor and the real temperature of the cells is particularly significant when large current charging and discharging, which makes the collected temperature unable to reflect the real temperature of the cells. The power output, capacity estimation and fault diagnosis are all affected by temperature, and if the real temperature of the cells cannot be obtained, the battery management system will be misjudged, which will affect the accuracy of SOX (State Of X, different battery state parameters such as SOP (State Of Power, power state), SOC (State Of Charge, state of charge), SOH (State Of Health, health state), SOE (State of Energy, energy state)) estimation and the performance of the cells.

[0061] The heat generation inside a lithium ion battery is a non-steady heat generation problem, which is mainly from three parts: reversible chemical reaction heat, battery polarization heat and battery ohmic heat, while the heat dissipation of the battery includes natural convection and forced convection. In order to reflect the detailed heat generation of the reaction cell, relevant researchers establish a complex multi-dimensional thermal coupling model through complex working condition simulation and test calibration. In the field of new energy vehicle application, the acquisition of traditional multi-dimensional electro-thermal coupling model is limited by cost and development cycle, and the practicability is poor. In addition, due to the different arrangement positions of each battery module in the battery system, the actual battery heat generation is different due to the influence of different ventilation effects and the heat balance of the whole package, which cannot be characterized by a unified electro-thermal coupling model.

[0062] Based on the above problems, the embodiment of the application provides a power battery pack cell temperature online compensation method. A plurality of temperature sensor groups are obtained by grouping a plurality of temperature sensors based on the current power battery pack. Based on the plurality of temperature sensor groups and the current working condition of the current power battery pack, a temperature rise rate value of the compensation temperature of each temperature sensor group is obtained, and based on the temperature rise rate value of the compensation temperature of each temperature sensor group, a compensation temperature value of each temperature sensor group is obtained. The cell temperature of the current power battery pack is compensated based on the acquisition temperature value of each temperature sensor group and the compensation temperature value of each temperature sensor group, and an actual cell temperature array of the current power battery pack is obtained. Therefore, the influence of busbar heat generation caused by current on the temperature acquisition of the temperature sensor can be effectively eliminated, thereby improving the accuracy of temperature diagnosis.

[0063] The power battery pack cell temperature online compensation method will be described in detail below.

[0064] As shown in the example of Figure 1 The power battery pack cell temperature online compensation method includes the following steps:

[0065] In step S101, a plurality of temperature sensors of the current power battery pack are determined, and a plurality of temperature sensor groups are obtained by grouping based on the plurality of temperature sensors.

[0066] It can be understood that in the power battery pack, a plurality of temperature sensors are usually arranged to monitor the temperature of the battery module. Due to the complex structure of the battery pack, the natural convection of the arrangement position of each temperature sensor and the influence of the whole package heat balance are different, which causes the temperature data collected by the temperature sensors at different positions to be interfered to different degrees. Therefore, the temperature sensors can be grouped according to certain rules, for example, the number of temperature sensor groups can be divided according to the number of temperature sensors, and each temperature sensor group includes one temperature sensor. This grouping method can more accurately reflect the temperature characteristics of different regions and provide a basis for subsequent temperature compensation.

[0067] In step S102, a current working condition of the current power battery pack is determined, a temperature rise rate value of the compensation temperature of each temperature sensor group is obtained based on the plurality of temperature sensor groups and the current working condition, and a compensation temperature value of each temperature sensor group is obtained based on the temperature rise rate value of the compensation temperature of each temperature sensor group.

[0068] The current working condition can be divided into a preset charging working condition (charging) and a preset discharging working condition (discharging).

[0069] It can be understood that, since the working condition (such as charging, discharging, etc.) of the power battery pack has a greater impact on the temperature, the current working condition of the current power battery pack needs to be determined first, so as to select a suitable compensation strategy according to the current working condition. For each temperature sensor group, a temperature rise rate value V extra_i of the compensation temperature thereof can be obtained through a calibration working condition test (such as testing under the preset charging working condition and the preset discharging working condition). The temperature rise rate value can reflect the influence degree of the busbar heat generation on the temperature collected by the temperature sensor. Then, according to the temperature rise rate value and the time, a compensation temperature value T extra_i of each temperature sensor group can be further calculated. The compensation temperature value can represent a part that needs to be subtracted from the temperature collected by the temperature sensor, so as to eliminate the error caused by the busbar heat generation.

[0070] For the convenience of understanding, how to obtain the temperature rise rate value of the compensation temperature of each temperature sensor group under different working conditions will be described in detail below.

[0071] As a possible implementation manner, in some embodiments, the current working condition is the preset charging working condition, and the temperature rise rate value of the compensation temperature of each temperature sensor group is obtained based on the plurality of temperature sensor groups and the current working condition, including: determining a first calibration working condition test condition; performing a first calibration working condition test based on the first calibration working condition test condition, and obtaining first thermocouple change data of a thermocouple arranged at a preset position of the current power battery pack, first change data of each temperature sensor group, and first current data; fitting to obtain a first actual temperature rise rate of the cell temperature of the current power battery pack under the first calibration working condition test based on the first thermocouple change data and the first current data; obtaining a first temperature rise rate of each temperature sensor group based on the first change data of each temperature sensor group, and obtaining a first temperature rise rate value of the compensation temperature of each temperature sensor group based on the first temperature rise rate of each temperature sensor group and the first actual temperature rise rate of the cell temperature.

[0072] Specifically, when performing the calibration condition test, an additional thermocouple needs to be arranged to monitor the real temperature of the surface of the battery cell. The thermocouple can be arranged at the closest tab of the battery cell to the temperature sensor (i.e., the preset position). In order to ensure the accuracy of the semi-empirical formula, the test can be performed under the operating condition close to the user's driving habits. When the current condition is the preset charging condition, the first calibration condition test can be performed under three different environmental temperature nodes of 10℃, 25℃ and 40℃, and at each temperature node, the charging condition test (i.e., the first calibration condition test) is performed according to the fast charging map (i.e., the relationship between the charging power and the state of the battery) specified by the battery manufacturer. During the test, the state of charge of the battery is gradually increased from 0% to 100%, i.e., a full charge test is performed. During the test, the real-time change data of the thermocouple and the temperature sensor during the charging process is recorded in detail, i.e., the first thermocouple change data, the first change data of each temperature sensor group and the first current data, for subsequent analysis.

[0073] By combining the first thermocouple change data with the time variable and the first current data, a quadratic polynomial formula is fitted, which can be used to represent the temperature rise rate V cell_i (i.e., the first actual temperature rise rate of the cell temperature of the current battery pack), and at the same time, the temperature rise rate V sensor_i (i.e., the first temperature rise rate of each temperature sensor group) can be calculated synchronously by using the temperature data (i.e., the first change data of each temperature sensor group) monitored by the temperature sensor installed on the surface of the battery. Finally, by subtracting the first temperature rise rate of each temperature sensor group from the first actual temperature rise rate of the cell temperature, the first temperature rise rate value V extra_i of the compensation temperature of each temperature sensor group can be obtained, i.e., extra_i V sensor_i = V cell_i i

[0074] Therefore, through double data monitoring and analysis, the temperature change of the battery under different conditions can be more comprehensively mastered, and a scientific basis for the thermal management of the battery can be provided.

[0075] As a possible implementation, in some embodiments, the current working condition is a preset discharge working condition, and the compensation temperature of each temperature sensor group is obtained based on the plurality of temperature sensor groups and the current working condition, including: determining a second calibration working condition test condition; performing a second calibration working condition test based on the second calibration working condition test condition, and obtaining second thermocouple change data of a thermocouple arranged at a preset position of the current power battery pack, second change data of each temperature sensor group, and second current data; based on the second thermocouple change data and the second current data, a second actual temperature rise rate of the cell temperature of the current power battery pack under the second calibration working condition test is fitted; based on the second change data of each temperature sensor group, a second temperature rise rate of each temperature sensor group is obtained, and based on the second temperature rise rate of each temperature sensor group and the second actual temperature rise rate of the cell temperature, a second temperature rise rate value of the compensation temperature of each temperature sensor group is obtained.

[0076] Specifically, when the current working condition is a preset discharge working condition, the second calibration working condition test condition can be set to two different environmental temperature nodes of 25°C and 40°C. In the environment of 25°C, the discharge test can be performed according to the China Light-duty Vehicle Test Cycle (CLTC); and in the environment of 40°C, the discharge test can be performed according to the rated 40kW working condition. During the test, the discharge state of the battery gradually decreases from 100% to 0%. Similarly, during the discharge process, the change data of the thermocouple and the temperature sensor, i.e., the second thermocouple change data, the second change data of each temperature sensor group, and the second current data, also need to be recorded.

[0077] Similarly, through the second thermocouple change data, combined with the time variable and the second current data, a quadratic polynomial formula is fitted, which can be used to represent the temperature rise rate V cell_i of the battery surface under the actual working condition (i.e., the second actual temperature rise rate of the cell temperature of the current power battery pack). At the same time, using the temperature data (i.e., the second change data of each temperature sensor group) monitored by the temperature sensor installed on the surface of the battery in real time, the temperature rise rate V sensor_i of the temperature sensor group itself can be calculated synchronously (i.e., the second temperature rise rate of each temperature sensor group). Finally, by subtracting the second temperature rise rate of each temperature sensor group from the second actual temperature rise rate of the cell temperature, the second temperature rise rate value V extra_i of the compensation temperature of each temperature sensor group can be obtained. extra_i sensor_i cell_i wherein i is the i-th temperature sensor group.

[0078] ​​Next, how to obtain the compensated temperature value of each temperature sensor group is described in detail.

[0079] As a possible implementation method, in some embodiments, the current operating condition is a preset charging condition, and the compensated temperature value of each temperature sensor group is obtained based on the temperature rise rate value of the compensated temperature of each temperature sensor group, including: integrating the first temperature rise rate value of the compensated temperature of each temperature sensor group within a first preset time to obtain the first compensated temperature value of each temperature sensor group.

[0080] Specifically, when the current working condition is the preset charging working condition, for each temperature sensor group, by integrating the first temperature rise rate value of the compensation temperature of each temperature sensor group within the first preset time, the first compensation temperature value T of each temperature sensor group can be obtained. extra_i In practical applications, integration can be achieved through discrete time methods, namely: T extra_i =∑V extra_i *t, where t is the first preset time.

[0081] As a possible implementation method, in other embodiments, the current operating condition is a preset discharge operating condition, and the compensated temperature value of each temperature sensor group is obtained based on the temperature rise rate value of the compensated temperature of each temperature sensor group, including: integrating the second temperature rise rate value of the compensated temperature of each temperature sensor group within the second preset time to obtain the second compensated temperature value of each temperature sensor group.

[0082] Specifically, when the current working condition is the preset discharge working condition, similarly, for each temperature sensor group, by integrating the second temperature rise rate value of the compensation temperature of each temperature sensor group within the second preset time, the second compensation temperature value T of each temperature sensor group can be obtained. extra_i , that is: T extra_i =∑V extra_i *t, where t is the second preset time.

[0083] In step S103, the collected temperature value of each temperature sensor group is obtained, and based on the collected temperature value of each temperature sensor group and the compensated temperature value of each temperature sensor group, the cell temperature of the current power battery pack is compensated to obtain an actual cell temperature array of the current power battery pack.

[0084] That is to say, after obtaining the compensation temperature value of each temperature sensor group, the collected temperature value T of each temperature sensor group can be obtained. sensor_i And compare the collected temperature value of each temperature sensor group with the corresponding compensation temperature value T extra_iThe comprehensive calculation is performed to obtain the actual cell temperature T of the current power battery pack corresponding to each group of temperature sensor groups cell_i . In this way, the cell temperature of the current power battery pack is accurately compensated, so that a more accurate and reliable actual cell temperature array {T cell_1 , T cell_2 , …, T cell_i,} of the current power battery pack is finally obtained, thereby providing strong data support for safe and efficient operation of the power battery pack.

[0085] As a possible implementation manner, in some embodiments, the cell temperature of the current power battery pack is compensated based on the collected temperature value of each group of temperature sensor groups and the compensation temperature value of each group of temperature sensor groups to obtain an actual cell temperature array of the current power battery pack, including: respectively performing difference calculation on the collected temperature value of each group of temperature sensor groups and the compensation temperature value of the corresponding group of temperature sensor groups to obtain a calculation result corresponding to each group of temperature sensor groups; and obtaining the actual cell temperature array of the current power battery pack according to the calculation result corresponding to each group of temperature sensor groups.

[0086] That is, each actual cell temperature T cel_i in the actual cell temperature array of the current power battery pack is equal to the collected temperature value T sensor_i of each group of temperature sensor groups minus the corresponding compensation temperature value T extra_i , and according to the actual cell temperature T cell_i of the current power battery pack corresponding to each group of temperature sensor groups, the actual cell temperature array {T cell_1 , T cell_2 , …, T cell_i,} of the current power battery pack can be obtained.

[0087] The actual cell temperature array of the current power battery pack obtained in this way can more accurately reflect the real state of the battery and provide more reliable temperature information for the battery management system, thereby improving the performance and safety of the battery.

[0088] It should be noted that considering that the accuracy of the temperature signal is 1℃, it is recommended that in actual operation, only when the compensation temperature value T extra_iOnly when the temperature exceeds 1℃, the temperature compensation mechanism of the embodiment of the present application is started, thereby ensuring the necessity and effectiveness of temperature compensation. In the process of implementing temperature compensation, a reasonable upper threshold of compensation temperature can be set. On the one hand, setting the upper threshold can effectively avoid excessive temperature compensation, which may cause the current charging rate obtained by table lookup to be too large, thereby causing lithium precipitation of the battery cell; on the other hand, the reasonable upper threshold can also prevent the temperature of the entire battery pack from being too high, thereby avoiding the risk of thermal runaway and ensuring the overall safety of the battery system. Therefore, when the temperature collected by the temperature sensor exceeds the preset upper threshold T upVal ℃, the temperature compensation value of the temperature collected by all temperature sensors can be immediately prohibited from continuing to rise, so as to prevent potential safety hazards. According to actual application experience and safety considerations, the value of T upVal may be set to be between 65℃ and 75℃, which can effectively control the amplitude of temperature compensation and ensure that the battery system operates within a safe temperature range.

[0089] According to the online compensation method for the battery cell temperature of the power battery pack proposed in the embodiment of the present application, a plurality of temperature sensor groups are obtained by grouping based on a plurality of temperature sensors of the current power battery pack; a temperature rise rate value of the compensation temperature of each temperature sensor group is obtained based on the plurality of temperature sensor groups and the current working condition of the current power battery pack, and a compensation temperature value of each temperature sensor group is obtained based on the temperature rise rate value of the compensation temperature of each temperature sensor group; the battery cell temperature of the current power battery pack is compensated based on the collected temperature value of each temperature sensor group and the compensation temperature value of each temperature sensor group, and an actual battery cell temperature array of the current power battery pack is obtained. Thus, the real-time temperature compensation value of each temperature sensor can be calculated online, and the real temperature of the battery pack is obtained, thereby solving the problem of inaccurate estimation of the battery cell temperature of the power battery pack in the prior art, achieving fine management of the battery pack, and improving the accuracy of SOX state regulation.

[0090] Secondly, the online compensation device for the battery cell temperature of the power battery pack proposed in the embodiment of the present application is described with reference to the accompanying drawings.

[0091] Figure 2 is a block schematic diagram of the online compensation device for the battery cell temperature of the power battery pack according to an embodiment of the present application.

[0092] As shown in Figure 2 , the online compensation device for the battery cell temperature of the power battery pack 10 includes a grouping module 100, an obtaining module 200, and a compensation module 300.

[0093] The grouping module 100 is configured to determine a plurality of temperature sensors of a current power battery pack, and obtain a plurality of temperature sensor groups based on the plurality of temperature sensors.

[0094] The obtaining module 200 is configured to determine a current working condition of the current power battery pack, obtain a temperature rise rate value of a compensated temperature of each temperature sensor group based on the plurality of temperature sensor groups and the current working condition, and obtain a compensated temperature value of each temperature sensor group based on the temperature rise rate value of the compensated temperature of each temperature sensor group.

[0095] The compensation module 300 is configured to obtain a collected temperature value of each temperature sensor group, and compensate a cell temperature of the current power battery pack based on the collected temperature value of each temperature sensor group and the compensated temperature value of each temperature sensor group to obtain an actual cell temperature array of the current power battery pack.

[0096] Optionally, in some embodiments, the current working condition is a preset charging working condition, and the obtaining module 200 is specifically configured to:

[0097] determine a first calibration working condition test condition;

[0098] perform a first calibration working condition test based on the first calibration working condition test condition, and obtain first thermocouple change data of a thermocouple arranged at a preset position of the current power battery pack, first change data of each temperature sensor group, and first current data;

[0099] fit to obtain a first actual temperature rise rate of a cell temperature of the current power battery pack in the first calibration working condition test based on the first thermocouple change data and the first current data;

[0100] obtain a first temperature rise rate of each temperature sensor group based on the first change data of each temperature sensor group, and obtain a first temperature rise rate value of a compensated temperature of each temperature sensor group based on the first temperature rise rate of each temperature sensor group and the first actual temperature rise rate of the cell temperature.

[0101] Optionally, in some embodiments, the current working condition is a preset discharging working condition, and the obtaining module 200 is specifically configured to:

[0102] determine a second calibration working condition test condition;

[0103] perform a second calibration working condition test based on the second calibration working condition test condition, and obtain second thermocouple change data of a thermocouple arranged at a preset position of the current power battery pack, second change data of each temperature sensor group, and second current data;

[0104] fit to obtain a second actual temperature rise rate of a cell temperature of the current power battery pack in the second calibration working condition test based on the second thermocouple change data and the second current data;

[0105] Based on the second change data of each temperature sensor group, a second temperature rise rate of each temperature sensor group is obtained, and based on the second temperature rise rate of each temperature sensor group and the second actual temperature rise rate of the battery cell temperature, a second temperature rise rate value of the compensated temperature of each temperature sensor group is obtained.

[0106] Optionally, in some embodiments, the current working condition is a preset charging working condition, and the obtaining module 200 is specifically used for:

[0107] The first compensation temperature value of each temperature sensor group is obtained by respectively integrating the first temperature rise rate value of the compensated temperature of each temperature sensor group within a first preset time.

[0108] Optionally, in some embodiments, the current working condition is a preset discharging working condition, and the obtaining module 200 is specifically used for:

[0109] The second compensation temperature value of each temperature sensor group is obtained by respectively integrating the second temperature rise rate value of the compensated temperature of each temperature sensor group within a second preset time.

[0110] Optionally, in some embodiments, the compensation module 300 is specifically used for:

[0111] The calculation result corresponding to each temperature sensor group is obtained by respectively performing difference calculation on the collected temperature value of each temperature sensor group and the compensated temperature value of the corresponding temperature sensor group.

[0112] The actual battery cell temperature array of the current power battery pack is obtained according to the calculation result corresponding to each temperature sensor group.

[0113] It should be noted that the foregoing explanation and description of the power battery pack battery cell temperature online compensation method embodiment also apply to the power battery pack battery cell temperature online compensation device of this embodiment, which will not be described here again.

[0114] The power battery pack cell temperature online compensation device provided by the embodiment of the application obtains multiple temperature sensor groups through multiple temperature sensors of the current power battery pack; obtains the temperature rise rate value of the compensation temperature of each temperature sensor group based on the multiple temperature sensor groups and the current working condition of the current power battery pack, and obtains the compensation temperature value of each temperature sensor group based on the temperature rise rate value of the compensation temperature of each temperature sensor group; compensates the cell temperature of the current power battery pack based on the collected temperature value of each temperature sensor group and the compensation temperature value of each temperature sensor group, and obtains the actual cell temperature array of the current power battery pack. Therefore, the real-time temperature compensation value of each temperature sensor can be calculated online, and the real temperature of the battery pack is obtained, the problem of inaccurate estimation of the cell temperature of the power battery pack in the prior art is solved, the fine management of the battery pack is realized, and the accuracy of SOX state regulation is improved.

[0115] Figure 3 The vehicle provided by the embodiment of the application is shown in the structural schematic diagram. The vehicle can include:

[0116] The memory 301, the processor 302, and the computer program stored in the memory 301 and executable on the processor 302.

[0117] The processor 302 implements the power battery pack cell temperature online compensation method provided in the above embodiment when executing the program.

[0118] Further, the vehicle further includes:

[0119] The communication interface 303 is used for communication between the memory 301 and the processor 302.

[0120] The memory 301 is used for storing the computer program executable on the processor 302.

[0121] The memory 301 can include a high-speed RAM (Random Access Memory, random access memory) memory, and can also include a non-volatile memory, for example, at least one disk memory.

[0122] If the memory 301, the processor 302 and the communication interface 303 are implemented independently, the communication interface 303, the memory 301 and the processor 302 can be connected with each other through a bus and complete communication between each other. The bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For the convenience of representation, Figure 3 Only one thick line is used in the figure to represent the bus, but it does not mean that there is only one bus or only one type of bus.

[0123] Optionally, in a specific implementation, if the memory 301, the processor 302 and the communication interface 303 are integrated on a chip, the memory 301, the processor 302 and the communication interface 303 can complete communication between each other through an internal interface.

[0124] The processor 302 can be a CPU (Central Processing Unit), or an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement one or more embodiments of the present application.

[0125] The embodiments of the present application also provide a computer readable storage medium, which stores a computer program, and the program is executed by a processor to implement the power battery pack cell temperature online compensation method.

[0126] In addition, the terms "first", "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, for example, two, three, etc., unless otherwise explicitly and specifically limited.

[0127] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are contained in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms is not necessarily directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction.

[0128] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and the person skilled in the art can make changes, modifications, replacements and variations to the above-described embodiments within the scope of the present application.

Claims

1. A method for online compensation of temperature of power battery pack cells, characterized in that, The method comprises the following steps: determining a plurality of temperature sensors of a current power battery pack, and grouping the plurality of temperature sensors into a plurality of temperature sensor groups based on the plurality of temperature sensors; determining a current working condition of the current power battery pack, obtaining a temperature rise rate value of a compensated temperature of each temperature sensor group based on the plurality of temperature sensor groups and the current working condition, and obtaining a compensated temperature value of each temperature sensor group based on the temperature rise rate value of the compensated temperature of each temperature sensor group; obtaining an acquisition temperature value of each temperature sensor group, and compensating a cell temperature of the current power battery pack based on the acquisition temperature value of each temperature sensor group and the compensated temperature value of each temperature sensor group to obtain an actual cell temperature array of the current power battery pack.

2. The method of claim 1, wherein, The current working condition is a preset charging working condition, and the obtaining of the temperature rise rate value of the compensated temperature of each temperature sensor group based on the plurality of temperature sensor groups and the current working condition comprises: determining a first calibration working condition test condition; performing a first calibration working condition test based on the first calibration working condition test condition, and obtaining first thermocouple change data of a thermocouple arranged at a preset position of the current power battery pack, first change data of each temperature sensor group, and first current data; fitting to obtain a first actual temperature rise rate of the cell temperature of the current power battery pack under the first calibration working condition test based on the first thermocouple change data and the first current data; obtaining a first temperature rise rate of each temperature sensor group based on the first change data of each temperature sensor group, and obtaining the first temperature rise rate value of the compensated temperature of each temperature sensor group based on the first temperature rise rate of each temperature sensor group and the first actual temperature rise rate of the cell temperature.

3. The method of claim 2, wherein, The current working condition is a preset discharging working condition, and the obtaining of the temperature rise rate value of the compensated temperature of each temperature sensor group based on the plurality of temperature sensor groups and the current working condition comprises: determining a second calibration working condition test condition; performing a second calibration working condition test based on the second calibration working condition test condition, and obtaining second thermocouple change data of a thermocouple arranged at a preset position of the current power battery pack, second change data of each temperature sensor group, and second current data; fitting to obtain a second actual temperature rise rate of the cell temperature of the current power battery pack under the second calibration working condition test based on the second thermocouple change data and the second current data; obtaining a second temperature rise rate of each temperature sensor group based on the second change data of each temperature sensor group, and obtaining the second temperature rise rate value of the compensated temperature of each temperature sensor group based on the second temperature rise rate of each temperature sensor group and the second actual temperature rise rate of the cell temperature.

4. The method of claim 2, wherein, The current working condition is a preset charging working condition, and the obtaining of the temperature rise rate value of the compensated temperature of each temperature sensor group based on the plurality of temperature sensor groups and the current working condition comprises: Integrate the first temperature rise rate value of the compensation temperature of each of the temperature sensor groups in a first preset time to obtain a first compensation temperature value of each of the temperature sensor groups.

5. The method of claim 3, wherein, The current working condition is a preset discharge working condition, and the compensation temperature value of each of the temperature sensor groups is obtained based on the temperature rise rate value of the compensation temperature of each of the temperature sensor groups. Integrate the second temperature rise rate value of the compensation temperature of each of the temperature sensor groups in a second preset time to obtain a second compensation temperature value of each of the temperature sensor groups.

6. The method of claim 1, wherein, The actual cell temperature array of the current power battery pack is obtained by compensating the cell temperature of the current power battery pack based on the collected temperature value of each of the temperature sensor groups and the compensation temperature value of each of the temperature sensor groups. Differentially calculate the collected temperature value of each of the temperature sensor groups and the compensation temperature value of the corresponding temperature sensor group to obtain a corresponding calculation result of each of the temperature sensor groups. The actual cell temperature array of the current power battery pack is obtained based on the corresponding calculation result of each of the temperature sensor groups.

7. A power battery pack cell temperature online compensation device, characterized in that, The method comprises the following steps: A grouping module is configured to determine a plurality of temperature sensors of a current power battery pack, and group the plurality of temperature sensors to obtain a plurality of temperature sensor groups; An obtaining module is configured to determine a current working condition of the current power battery pack, obtain a temperature rise rate value of the compensation temperature of each of the temperature sensor groups based on the plurality of temperature sensor groups and the current working condition, and obtain a compensation temperature value of each of the temperature sensor groups based on the temperature rise rate value of the compensation temperature of each of the temperature sensor groups. A compensation module is configured to obtain a collected temperature value of each of the temperature sensor groups, and compensate the cell temperature of the current power battery pack based on the collected temperature value of each of the temperature sensor groups and the compensation temperature value of each of the temperature sensor groups to obtain an actual cell temperature array of the current power battery pack.

8. The apparatus of claim 7, wherein, The current working condition is a preset charging working condition, and the obtaining module is specifically configured to: Determine a first calibration working condition test condition; Perform a first calibration working condition test based on the first calibration working condition test condition, and obtain first thermocouple change data of a thermocouple arranged at a preset position of the current power battery pack, first change data of each of the temperature sensor groups, and first current data; Based on the first thermocouple change data and the first current data, a first actual temperature rise rate of the cell temperature of the current power battery pack under the first calibration working condition test is fitted and obtained; Based on the first change data of each of the temperature sensor groups, a first temperature rise rate of each of the temperature sensor groups is obtained, and based on the first temperature rise rate of each of the temperature sensor groups and the first actual temperature rise rate of the cell temperature, a first temperature rise rate value of the compensation temperature of each of the temperature sensor groups is obtained.

9. A vehicle characterized by comprising: The method comprises the following steps: A memory, a processor, and a computer program stored on the memory and executable on the processor, the processor executing the program to implement the method of claim 1-6.

10. A computer-readable storage medium having stored thereon a computer program, characterized in that, The program is executed by the processor for implementing the method of claim 1-6.

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