Method and device for estimating maximum temperature of battery module and electronic equipment

Abstract

The invention provides a maximum temperature estimation method and device for a battery module and electronic equipment, and the method comprises the steps: constructing a three-dimensional dual-state heat transfer model of a to-be-evaluated battery module, the three-dimensional dual-state heat transfer model is used for representing a heat transfer model under the condition of considering the highest temperature and each surface temperature of the battery module to be evaluated; performing parameter identification on the three-dimensional dual-state heat transfer model to obtain a first identified parameter of the three-dimensional dual-state heat transfer model, and substituting the first identified parameter into the three-dimensional dual-state heat transfer model to obtain a target three-dimensional dual-state heat transfer model; and the total heat production amount of the to-be-evaluated battery module is acquired in real time, and the highest temperature of the to-be-evaluated battery module is estimated based on the total heat production amount and the target three-dimensional double-state heat transfer model. The highest temperature of the battery module can be accurately and efficiently estimated, so that the safety performance of the battery module can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power system energy storage control, and in particular to a method, device and electronic equipment for estimating the maximum temperature of a battery module. Background Art

[0002] Lithium-ion batteries, with their high energy density, fast response speed and long cycle life, have become core components in energy storage systems and electric vehicles. Their wide application has not only promoted the rapid development of the new energy industry, but also put forward more stringent requirements on the safety performance of batteries. During the operation of the battery, in order to ensure the stable operation of the battery system, it is necessary to accurately estimate the maximum temperature of the battery module.

[0003] It is known from related technologies that the maximum temperature of battery modules is often estimated based on the electric coupling model. However, the heat transfer differences of batteries or modules in various directions in three-dimensional space are ignored in the estimation process. This simplified processing causes the estimation of the maximum temperature to be affected by the uneven temperature distribution on different surfaces of the battery, thereby reducing the accuracy of the prediction.

[0004] Therefore, finding a method that can accurately and efficiently estimate the maximum temperature of the battery module has become a current research hotspot. Summary of the invention

[0005] The present invention provides a method, device and electronic equipment for estimating the maximum temperature of a battery module, which can accurately and efficiently estimate the maximum temperature of a battery module, thereby improving the safety performance of the battery module.

[0006] The present invention provides a method for estimating the maximum temperature of a battery module, the method comprising: constructing a three-dimensional two-state heat transfer model for a battery module to be evaluated, wherein the three-dimensional two-state heat transfer model is used to characterize a heat transfer model under the condition of considering the maximum temperature and each surface temperature of the battery module to be evaluated; performing parameter identification on the three-dimensional two-state heat transfer model to obtain a first identified parameter of the three-dimensional two-state heat transfer model, and substituting the first identified parameter into the three-dimensional two-state heat transfer model to obtain a target three-dimensional two-state heat transfer model; acquiring the total heat generation of the battery module to be evaluated in real time, and estimating the maximum temperature of the battery module to be evaluated based on the total heat generation and the target three-dimensional two-state heat transfer model.

[0007] According to a method for estimating the maximum temperature of a battery module provided by the present invention, the maximum temperature of the battery module to be evaluated is estimated based on the total heat generation and the target three-dimensional two-state heat transfer model, specifically comprising: determining, based on the total heat generation, the amount of heat transfer on each surface of the battery module to be evaluated on which the total heat generation is transferred; estimating the maximum temperature in each surface dimension based on each of the surface heat transfer amounts and the target three-dimensional two-state heat transfer model; estimating the maximum temperature of the battery module to be evaluated based on the maximum temperature in each surface dimension.

[0008] According to a method for estimating the maximum temperature of a battery module provided by the present invention, the maximum temperature of the battery module to be evaluated is estimated based on the maximum temperature in each surface dimension, specifically comprising: when the deviation between the maximum temperatures in each surface dimension is within a preset range, estimating the maximum temperature of the battery module to be evaluated based on the average value of the maximum temperatures in each surface dimension; when the deviation between the maximum temperatures in each surface dimension is outside the preset range, repeatedly performing the steps of redistributing the heat transfer amount of each surface to obtain the heat transfer amount of the redistributed surface, and estimating the maximum temperature in each surface dimension based on the heat transfer amount of the redistributed surface and the target three-dimensional two-state heat transfer model, until the deviation between the maximum temperatures in each surface dimension is within the preset range, and estimating the maximum temperature of the battery module to be evaluated based on the average value of the maximum temperatures in each surface dimension.

[0009] According to a maximum temperature estimation method for a battery module provided by the present invention, the surface heat transfer is redistributed to obtain the reallocated surface heat transfer, which is achieved in the following manner: the maximum temperature in each surface dimension is sorted in descending order to obtain a sorted sequence; part of the surface heat transfer of the surface dimension that is ranked in the front preset number of the sorted sequence is allocated to the surface heat transfer of the surface dimension that is ranked in the back preset number of the sorted sequence.

[0010] According to a maximum temperature estimation method of a battery module provided by the present invention, the determining, based on the total heat generation, the amount of heat transfer on each surface of the battery module to be evaluated for heat transfer by the total heat generation specifically includes: allocating the total heat generation according to the surface area of ​​each surface of the battery module to be evaluated to obtain the amount of heat transfer on each surface of the battery module to be evaluated for heat transfer by the total heat generation.

[0011] According to a maximum temperature estimation method for a battery module provided by the present invention, parameter identification is performed on the three-dimensional two-state heat transfer model to obtain the first identified parameters of the three-dimensional two-state heat transfer model, which is achieved in the following manner: determining the surface temperature, ambient temperature, and heat transfer amount of each surface of the battery module to be evaluated; and performing parameter identification on the three-dimensional two-state heat transfer model based on the surface temperature, the ambient temperature, and the heat transfer amount of each surface to obtain the first identified parameters of the three-dimensional two-state heat transfer model.

[0012] According to a maximum temperature estimation method for a battery module provided by the present invention, a three-dimensional two-state heat transfer model for a battery module to be evaluated is constructed, and the model is implemented in the following manner: while considering the maximum temperature and each surface temperature of the battery module to be evaluated, discretization processing is performed based on the three-dimensional heat transfer model to construct a three-dimensional two-state heat transfer model for the battery module to be evaluated.

[0013] According to a method for estimating the maximum temperature of a battery module provided by the present invention, after the maximum temperature of the battery module to be evaluated is estimated, the method further includes: performing equivalent processing on the battery module to be evaluated to obtain a Thevenin equivalent circuit model of the battery module corresponding to the battery module to be evaluated; performing parameter identification on the Thevenin equivalent circuit model of the battery module to obtain second identified parameters; substituting the second identified parameters into the Thevenin equivalent circuit model of the battery module to obtain a heat generation model of the battery module to be evaluated; obtaining an average battery temperature of the battery module to be evaluated based on the maximum temperature of the battery module to be evaluated and the surface temperatures of the battery module to be evaluated; and determining the energy efficiency of the battery module to be evaluated based on the heat generation model and the average battery temperature of the battery module to be evaluated.

[0014] The present invention also provides a device for estimating the maximum temperature of a battery module, the device comprising: a construction module, used to construct a three-dimensional two-state heat transfer model for the battery module to be evaluated, wherein the three-dimensional two-state heat transfer model is used to characterize the heat transfer model under the condition of considering the maximum temperature and each surface temperature of the battery module to be evaluated; an identification module, used to perform parameter identification on the three-dimensional two-state heat transfer model to obtain a first identified parameter of the three-dimensional two-state heat transfer model, and substitute the first identified parameter into the three-dimensional two-state heat transfer model to obtain a target three-dimensional two-state heat transfer model; an estimation module, used to obtain the total heat generation of the battery module to be evaluated in real time, and estimate the maximum temperature of the battery module to be evaluated based on the total heat generation and the target three-dimensional two-state heat transfer model.

[0015] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, a maximum temperature estimation method for a battery module as described above is implemented.

[0016] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the method for estimating the maximum temperature of a battery module as described in any one of the above is implemented.

[0017] The present invention also provides a computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the method for estimating the maximum temperature of a battery module as described above is implemented.

[0018] The method, device and electronic device for estimating the maximum temperature of a battery module provided by the present invention construct a three-dimensional two-state heat transfer model for a battery module to be evaluated, wherein the three-dimensional two-state heat transfer model is used to characterize the heat transfer model under the condition of considering the maximum temperature and each surface temperature of the battery module to be evaluated; the three-dimensional two-state heat transfer model is parameter identified to obtain the first identified parameter of the three-dimensional two-state heat transfer model, and the first identified parameter is substituted into the three-dimensional two-state heat transfer model to obtain the target three-dimensional two-state heat transfer model; the total heat generation of the battery module to be evaluated is obtained in real time, and the maximum temperature of the battery module to be evaluated is estimated based on the total heat generation and the target three-dimensional two-state heat transfer model. The maximum temperature of the battery module can be accurately and efficiently estimated, thereby providing the safety performance of the battery module. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 This is one of the flow charts of the maximum temperature estimation method of the battery module provided by the present invention.

[0021] Figure 2 It is a flow chart of estimating the maximum temperature of the battery module to be evaluated based on the total heat generation and the target three-dimensional two-state heat transfer model provided by the present invention.

[0022] Figure 3 It is a schematic diagram of a flow chart for estimating the maximum temperature of the battery module to be evaluated based on the maximum temperature in each surface dimension provided by the present invention.

[0023] Figure 4 This is the second flow chart of the maximum temperature estimation method of the battery module provided by the present invention.

[0024] Figure 5 It is a structural schematic diagram of a maximum temperature estimation device for a battery module provided by the present invention.

[0025] Figure 6 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] The present invention provides a method for estimating the maximum temperature of a battery module, establishes a heat generation model that considers both reversible heat and irreversible heat, establishes a three-dimensional two-state thermal model, and solves the maximum temperature value based on an optimization algorithm. A feedback link is set in the heat generation model and the thermal model to achieve a joint estimation of energy efficiency and maximum temperature, thereby improving the perception capability of the battery management system and the system safety performance.

[0028] Figure 1 This is one of the flow charts of the maximum temperature estimation method of the battery module provided by the present invention.

[0029] The following will be combined Figure 1 The process of the maximum temperature estimation method of the battery module provided by the present invention is described.

[0030] In an exemplary embodiment of the present invention, Figure 1 It can be seen that the method for estimating the maximum temperature of the battery module may include steps 110 to 130, and each step will be introduced below.

[0031] In step 110 , a three-dimensional two-state heat transfer model for the battery module to be evaluated is constructed, wherein the three-dimensional two-state heat transfer model is used to characterize a heat transfer model under the condition of considering the maximum temperature and each surface temperature of the battery module to be evaluated.

[0032] In one embodiment, a three-dimensional two-state heat transfer model for the battery module to be evaluated may be constructed, wherein the three-dimensional two-state heat transfer model may be used to characterize a heat transfer model in consideration of the maximum temperature and various surface temperatures of the battery module to be evaluated.

[0033] In another exemplary embodiment of the present invention, constructing a three-dimensional two-state heat transfer model for a battery module to be evaluated may be implemented in the following manner: In consideration of the maximum temperature and surface temperatures of the battery module to be evaluated, discretization processing is performed based on the three-dimensional heat transfer model to construct a three-dimensional two-state heat transfer model for the battery module to be evaluated.

[0034] In one embodiment, a three-dimensional two-state heat transfer model of the battery module to be evaluated can be constructed based on discretization of the three-dimensional heat transfer model while taking into account the maximum temperature and each surface temperature of the battery module to be evaluated.

[0035] It should be noted that The cells are densely arranged in the module, making every point in the module a potential heat source. Therefore, the heat conduction within the module, that is, the heat conduction within the module in the three-dimensional heat transfer model, can be described by the following formula (1): (1) Where ρ represents the density of lithium-ion batteries, C c represents the specific heat capacity of the core; k x , k y and k z Respectively represent the thermal conductivity of the battery module in the x, y and z directions; d q : represents the heat generated by the microelement of the battery module; T represents the temperature of the microelement.

[0036] The heat conduction of the six surfaces of the module, that is, the surface in the three-dimensional heat transfer model, can be described by the following formula (2): (2) Among them, k s,i , T s, i and h i denote the thermal conductivity, temperature and convection heat transfer coefficient of the i-th surface, T a represents the ambient temperature, and n represents the direction. When the module contains cells of the same type and the aging difference is negligible, the heat capacity and thermal conductivity in the same direction within the module can be considered uniform.

[0037] Furthermore, by integrating both sides of the above equations (1)-(2) along the direction of each surface of the battery module to be evaluated, taking the positive direction of the x-axis as an example, and applying the heat transfer boundary conditions, that is, discretizing based on the three-dimensional heat transfer model, the following expression (3) can be obtained: (3) Among them, T s,x1 Indicates the temperature of the module surface in the x1 direction; Q x1Represents the portion of the total heat Q generated by the module that is transferred in the x1 direction; β x1 It indicates the contribution rate of Qx1 to the heating rate of the highest temperature point. Cc and C s，x1 are the internal and x1 surface heat capacities of the module, respectively. c,x1 is the thermal resistance between the highest temperature point and the x1 surface, and R u,x1 is the thermal resistance between the x1 surface and the surrounding airflow; T peak represents the maximum temperature. Similar equations can be written for the remaining surfaces, subject to the following constraint (4): (4) Among them, the values ​​of i are x1, x2, y1, y2, z1, z2. It can be understood that x1 and x2 are two surfaces in opposite directions along the x-axis; y1 and y2 are two surfaces in opposite directions along the y-axis; and z1 and z2 are two surfaces in opposite directions along the z-axis.

[0038] It can be understood that the above formulas (3) and (4) can be considered as the constructed three-dimensional two-state heat transfer model for the battery module to be evaluated.

[0039] In step 120, parameter identification is performed on the three-dimensional two-state heat transfer model to obtain first identified parameters of the three-dimensional two-state heat transfer model, and the first identified parameters are substituted into the three-dimensional two-state heat transfer model to obtain a target three-dimensional two-state heat transfer model.

[0040] In step 130 , the total heat generation of the battery module to be evaluated is acquired in real time, and the maximum temperature of the battery module to be evaluated is estimated based on the total heat generation and the target three-dimensional two-state heat transfer model.

[0041] In one embodiment, in order to estimate the maximum temperature in the module, it is first necessary to determine the parameters in the thermal model (corresponding to the first identified parameters), that is, to perform parameter identification on the three-dimensional two-state heat transfer model, obtain the first identified parameters of the three-dimensional two-state heat transfer model, and substitute the first identified parameters into the three-dimensional two-state heat transfer model, so as to obtain the target three-dimensional two-state heat transfer model.

[0042] Furthermore, the total heat generation of the battery module to be evaluated is obtained in real time, and the heat transfer amounts of each surface of the battery module to be evaluated are obtained based on the total heat generation. Then, based on the heat transfer amounts of each surface and the target three-dimensional two-state heat transfer model, the maximum temperature of the battery module to be evaluated is estimated.

[0043] The method for estimating the maximum temperature of a battery module provided by the present invention constructs a three-dimensional two-state heat transfer model for the battery module to be evaluated, wherein the three-dimensional two-state heat transfer model is used to characterize the heat transfer model under the condition of considering the maximum temperature and each surface temperature of the battery module to be evaluated; the three-dimensional two-state heat transfer model is parameter identified to obtain the first identified parameter of the three-dimensional two-state heat transfer model, and the first identified parameter is substituted into the three-dimensional two-state heat transfer model to obtain the target three-dimensional two-state heat transfer model; the total heat generation of the battery module to be evaluated is obtained in real time, and the maximum temperature of the battery module to be evaluated is estimated based on the total heat generation and the target three-dimensional two-state heat transfer model. The method realizes accurate and efficient estimation of the maximum temperature of the battery module, thereby providing the safety performance of the battery module.

[0044] Figure 2 It is a flow chart of estimating the maximum temperature of the battery module to be evaluated based on the total heat generation and the target three-dimensional two-state heat transfer model provided by the present invention.

[0045] The following will be combined Figure 2 The process of estimating the maximum temperature of the battery module to be evaluated based on the total heat generation and the target three-dimensional two-state heat transfer model provided by the present invention is described.

[0046] In an exemplary embodiment of the present invention, Figure 2 It can be seen that based on the total heat generation and the target three-dimensional two-state heat transfer model, estimating the maximum temperature of the battery module to be evaluated may include steps 210 to 230, and each step will be introduced below.

[0047] In step 210 , based on the total heat generation, the heat transfer amount of each surface where the total heat generation is transferred on each surface of the battery module to be evaluated is determined.

[0048] In one embodiment, based on the total heat generation, the heat transfer amount of each surface of the battery module to be evaluated can be determined, thereby laying a foundation for estimating the maximum temperature of the battery module to be evaluated in combination with the target three-dimensional two-state heat transfer model.

[0049] In another exemplary embodiment of the present invention, based on the total heat generation, determining the heat transfer amount of each surface of the battery module to be evaluated for heat transfer on the total heat generation can be achieved in the following manner: The total heat generation is distributed according to the surface area of ​​each surface of the battery module to be evaluated, and the heat transfer amount of each surface where the total heat generation is transferred on each surface of the battery module to be evaluated is obtained.

[0050] In one embodiment, initially, the total heat generated can be proportionally distributed according to the surface area of ​​each surface of each battery module to be evaluated, and the heat transfer amount of each surface of the battery module to be evaluated can be obtained to ensure initial balance. The following iterative adjustment process can be adopted in consideration of calculation efficiency and solution accuracy.

[0051] In step 220, based on the heat transfer amount of each surface and the target three-dimensional two-state heat transfer model, the maximum temperature in each surface dimension is estimated.

[0052] In step 230 , the maximum temperature of the battery module to be evaluated is estimated based on the maximum temperature in each surface dimension.

[0053] In another embodiment, the highest temperature in each surface dimension can be estimated based on the heat transfer amount of each surface and the target three-dimensional two-state heat transfer model. That is, if the heat Q transferred from the highest temperature point to the x1 direction is known, x1 (corresponding to the surface heat transfer), then by solving the formula of the target three-dimensional two-state heat transfer model, the thermal model in this direction is calculated to obtain the estimated maximum temperature (The highest temperature in each surface dimension). Similarly, by identifying the thermal model parameters in the other five directions, the corresponding maximum temperature values ​​can be calculated. , , , , Furthermore, the maximum temperature of the battery module to be evaluated may be estimated based on the calculated corresponding maximum temperature value.

[0054] Figure 3 It is a schematic diagram of a flow chart for estimating the maximum temperature of the battery module to be evaluated based on the maximum temperature in each surface dimension provided by the present invention.

[0055] The following will be combined Figure 3 The process of estimating the maximum temperature of the battery module to be evaluated based on the maximum temperature in each surface dimension is described.

[0056] In an exemplary embodiment of the present invention, Figure 3 It can be seen that estimating the maximum temperature of the battery module to be evaluated based on the maximum temperature in each surface dimension may include step 310 and step 320, and each step will be introduced below.

[0057] In step 310 , if the deviations between the maximum temperatures in various surface dimensions are within a preset range, the maximum temperature of the battery module to be evaluated is estimated based on the average value of the maximum temperatures in various surface dimensions.

[0058] It should be noted that since the maximum temperature of the battery module to be evaluated is one, ideally, the maximum temperature of each surface dimension should be the same. In practical applications, if the deviation between the maximum temperatures of each surface dimension is within the preset range, that is, , , , , , The deviation is not large, and within the preset range, it can be considered that there is no error, and then the maximum temperature of the battery module to be evaluated can be estimated based on the average value of the maximum temperature in each surface dimension. Among them, the preset range can be adjusted according to actual conditions and is not specifically limited in this embodiment.

[0059] In step 320, if the deviation between the maximum temperatures in each surface dimension is outside the preset range, the steps of redistributing the heat transfer of each surface to obtain the rear surface heat transfer after redistribution and estimating the maximum temperature in each surface dimension based on the rear surface heat transfer after redistribution and the target three-dimensional two-state heat transfer model are repeated until the deviation between the maximum temperatures in each surface dimension is within the preset range, and the maximum temperature of the battery module to be evaluated is estimated based on the average value of the maximum temperatures in each surface dimension.

[0060] In another embodiment, if the deviation between the maximum temperatures under each surface dimension is not within a preset range, that is, , , , , , If the deviation is large, it is likely due to the heat transfer parameter Qaxis={Q x1 , Q x2 , Q y1 , Q y2 , Q z1 , Q z2}, that is, it is caused by unreasonable setting of surface heat transfer, so it is necessary to use optimization algorithm to adjust the estimated maximum temperature.

[0061] In another embodiment, the steps of redistributing the heat transfer amount of each surface to obtain the rear surface heat transfer amount, and estimating the maximum temperature in each surface dimension based on the rear surface heat transfer amount and the target three-dimensional two-state heat transfer model can be repeated until the deviation between the maximum temperatures in each surface dimension is within a preset range, and the maximum temperature of the battery module to be evaluated is estimated based on the average value of the maximum temperatures in each surface dimension.

[0062] In the application process, the thermal model parameters in each direction are determined and estimated After that, 5% of the heat in the three directions with the highest maximum temperature can be redistributed to the three directions with the lowest heat output. This redistribution process is repeated iteratively until the maximum temperature deviation in all directions is minimized, that is, until the deviation between the maximum temperatures in each surface dimension is within a preset range, and then the maximum temperature of the battery module to be evaluated is estimated based on the average value of the maximum temperature in each surface dimension. This produces a more balanced heat distribution and higher estimation accuracy.

[0063] It should be noted that the deviation between the maximum temperatures in each surface dimension within a preset range can be expressed by the following formulas (5)-(6), where (6) is a constraint of (5): (5) (6) in, Indicates the maximum temperature at each surface dimension; represents the mean of the maximum temperature in each surface dimension; n represents the number of maximum temperatures in each surface dimension; Q i represents the surface heat transfer; Q represents the total heat generation.

[0064] In another exemplary embodiment of the present invention, continuing with the above Figure 3 The above embodiment is used as an example for explanation, wherein the redistribution of the heat transfer of each surface to obtain the redistributed surface heat transfer can be achieved in the following manner: Sort the highest temperatures in each surface dimension from large to small to obtain a sorted sequence; Part of the surface heat transfer of the surface dimension ranked at the front preset number of the sorting sequence is distributed to the surface heat transfer of the surface dimension ranked at the back preset number of the sorting sequence.

[0065] In one embodiment, 5% of the heat in the three directions with the highest maximum temperature can be reallocated to the three directions with the lowest heat output, that is, part of the heat of the surface heat transfer of the surface dimension in the first preset number of digits in the sorting sequence is allocated to the surface heat transfer of the surface dimension in the last preset number of digits in the sorting sequence. The first preset number of digits refers to the first three digits, and the last preset number of digits refers to the last three digits.

[0066] In another exemplary embodiment of the present invention, continuing with the above Figure 1 Taking the above embodiment as an example, the parameter identification of the three-dimensional two-state heat transfer model is performed to obtain the first identified parameters of the three-dimensional two-state heat transfer model, which can be achieved in the following manner: Determine the surface temperature, ambient temperature, and heat transfer of each surface of the battery module to be evaluated; The parameters of the three-dimensional two-state heat transfer model are identified based on the surface temperature, the ambient temperature and the heat transfer amount of each surface, and the first identified parameters of the three-dimensional two-state heat transfer model are obtained.

[0067] In one embodiment, in order to estimate the maximum temperature in the module, it is first necessary to determine the parameters in the thermal model, that is, the first identified parameters. It can be understood that for formula (3), the first identified parameters to be identified can be β x1 .C c ; R c,x1 ; C s,x1 ; R u,x1 Taking the x1 direction as an example, the transfer function can be written as formula (7): (7) After applying the Z transform, the discretized equation can be expressed as formula (8): (8) in: ; It should be noted that the subscript k in this embodiment represents the k moment. x1 (k) represents the surface heat transfer under the x1 surface at time k, that is, the part of the total heat Q generated by the module at time k that is transferred in the x1 direction. a (k) represents the ambient temperature at time k; T s,x1 (k) represents the temperature of the module surface in the x1 direction at time k, that is, the surface temperature at time k.

[0068] Furthermore, we can define: ; So we have: Based on this, the parameter identification of the three-dimensional two-state heat transfer model is completed, and the first identified parameter of the three-dimensional two-state heat transfer model is obtained, that is, the first identified parameter β x1 .C c ; R c,x1 ; C s,x1 ; R u,x1 .

[0069] Figure 4 This is the second flow chart of the maximum temperature estimation method of the battery module provided by the present invention.

[0070] The following will be combined Figure 4 A process of another method for estimating the maximum temperature of a battery module is described.

[0071] In an exemplary embodiment of the present invention, Figure 4 It can be seen that after estimating the maximum temperature of the battery module to be evaluated, the method for estimating the maximum temperature of the battery module further includes steps 410 to 450, and each step will be described below: In step 410, equivalent processing is performed on the battery module to be evaluated to obtain a Thevenin equivalent circuit model of the battery module corresponding to the battery module to be evaluated.

[0072] In step 420, parameter identification is performed on the Thevenin equivalent circuit model of the battery module to obtain second identified parameters.

[0073] In step 430 , the second identified parameters are substituted into the Thevenin equivalent circuit model of the battery module to obtain a heat generation model of the battery module to be evaluated.

[0074] In step 440 , the average battery temperature of the battery module to be evaluated is obtained based on the maximum temperature of the battery module to be evaluated and the surface temperatures of the battery module to be evaluated.

[0075] In step 450 , the energy efficiency of the battery module to be evaluated is determined based on the heat generation model and the average battery temperature of the battery module to be evaluated.

[0076] In one embodiment, the battery module to be evaluated can be processed equivalently to obtain a Thevenin equivalent circuit model of the battery module corresponding to the battery module to be evaluated. The heat generation rate in the battery module can be described by the following formula (9): (9) Among them, Q represents the total heat production rate; Uo c represents the open circuit voltage; I L Indicates the charging or discharging current of the battery; T ave Represents the average temperature of the entire battery, which is determined by the average of the maximum temperature and the surface temperature; U t Indicates the terminal voltage of the battery.

[0077] The two terms on the right side of equation (9) correspond to irreversible heat and reversible heat, respectively. Based on the Thevenin equivalent circuit model of the battery module, the above equation can be expressed as equation (10): (10) (11) Wherein, R0 represents the ohmic internal resistance of the battery; the variable Rp describes the polarization effect of the module and is the second identified parameter to be identified; U t,k represents the terminal voltage of the battery at time k; I L,krepresents the charging or discharging current of the battery at time k; Q k It is understood that formulas (10) and (11) can be expressed as the Thevenin equivalent circuit model of the battery module, corresponding to the heat generation model. The equivalent circuit model parameter estimation can be obtained by the least square method with forgetting factor.

[0078] Understandably, Q k That is, Q in formula (10) is based on the average temperature of the entire battery T ave It is calculated that in the application process, the average battery temperature of the battery module to be evaluated can be obtained based on the maximum temperature of the battery module to be evaluated and the surface temperature of the battery module to be evaluated. T ave Furthermore, by combining formula (10) and formula (11), that is, based on the heat generation model and the average battery temperature of the battery module to be evaluated, the energy efficiency η of the battery module to be evaluated can be determined: k .

[0079] According to the foregoing description, the maximum temperature estimation method of the battery module provided by the present invention constructs a three-dimensional two-state heat transfer model for the battery module to be evaluated, wherein the three-dimensional two-state heat transfer model is used to characterize the heat transfer model under the condition of considering the maximum temperature and each surface temperature of the battery module to be evaluated; the three-dimensional two-state heat transfer model is parameter identified to obtain the first identified parameter of the three-dimensional two-state heat transfer model, and the first identified parameter is substituted into the three-dimensional two-state heat transfer model to obtain the target three-dimensional two-state heat transfer model; the total heat generation of the battery module to be evaluated is obtained in real time, and based on the total heat generation and the target three-dimensional two-state heat transfer model, the maximum temperature of the battery module to be evaluated is estimated. The maximum temperature of the battery module can be accurately and efficiently estimated, thereby providing the safety performance of the battery module.

[0080] The maximum temperature estimation device for a battery module provided by the present invention is described below. The maximum temperature estimation device for a battery module described below and the maximum temperature estimation method for a battery module described above can be referred to each other.

[0081] Figure 5 It is a structural schematic diagram of a maximum temperature estimation device for a battery module provided by the present invention.

[0082] The following will be combined Figure 5 The structure of the maximum temperature estimation device for a battery module provided by the present invention is described.

[0083] In an exemplary embodiment of the present invention, Figure 5It can be seen that the maximum temperature estimation device of the battery module may include a construction module 510, an identification module 520, and an estimation module 530, and each module will be introduced below.

[0084] The construction module 510 may be configured to construct a three-dimensional two-state heat transfer model for the battery module to be evaluated, wherein the three-dimensional two-state heat transfer model is used to characterize a heat transfer model under the condition of considering the maximum temperature and each surface temperature of the battery module to be evaluated; The identification module 520 may be configured to perform parameter identification on the three-dimensional two-state heat transfer model to obtain first identified parameters of the three-dimensional two-state heat transfer model, and substitute the first identified parameters into the three-dimensional two-state heat transfer model to obtain a target three-dimensional two-state heat transfer model; The estimation module 530 may be configured to obtain the total heat generation of the battery module to be evaluated in real time, and estimate the maximum temperature of the battery module to be evaluated based on the total heat generation and the target three-dimensional two-state heat transfer model.

[0085] In an exemplary embodiment of the present invention, the estimation module 530 may estimate the maximum temperature of the battery module to be evaluated based on the total heat generation and the target three-dimensional two-state heat transfer model in the following manner: Based on the total heat generation, determining the amount of heat transferred on each surface of the battery module to be evaluated by transferring the total heat generation on each surface; Based on the heat transfer amount of each surface and the target three-dimensional two-state heat transfer model, estimating the maximum temperature in each surface dimension; Based on the maximum temperature in each surface dimension, the maximum temperature of the battery module to be evaluated is estimated.

[0086] In an exemplary embodiment of the present invention, the estimation module 530 may estimate the maximum temperature of the battery module to be evaluated based on the maximum temperature in each surface dimension in the following manner: When the deviation between the maximum temperatures in each surface dimension is within a preset range, the maximum temperature of the battery module to be evaluated is estimated based on the average value of the maximum temperatures in each surface dimension; If the deviation between the maximum temperatures in each surface dimension is outside the preset range, the steps of redistributing the heat transfer of each surface to obtain the rear surface heat transfer after redistribution, and estimating the maximum temperature in each surface dimension based on the rear surface heat transfer after redistribution and the target three-dimensional two-state heat transfer model are repeated until the deviation between the maximum temperatures in each surface dimension is within the preset range, and the maximum temperature of the battery module to be evaluated is estimated based on the average value of the maximum temperatures in each surface dimension.

[0087] In an exemplary embodiment of the present invention, the estimation module 530 may realize the redistribution of the heat transfer of each surface to obtain the redistributed surface heat transfer in the following manner: Sort the highest temperatures in each surface dimension from large to small to obtain a sorted sequence; Part of the surface heat transfer of the surface dimension ranked at the front preset number of the sorting sequence is distributed to the surface heat transfer of the surface dimension ranked at the back preset number of the sorting sequence.

[0088] In an exemplary embodiment of the present invention, the estimation module 530 may determine the heat transfer amount of each surface of the battery module to be evaluated based on the total heat generation by: The total heat generation is distributed according to the surface area of ​​each surface of the battery module to be evaluated to obtain the surface heat transfer amount of each surface where the total heat generation is transferred on each surface of the battery module to be evaluated.

[0089] In an exemplary embodiment of the present invention, the identification module 520 can implement parameter identification of the three-dimensional two-state heat transfer model in the following manner to obtain the first identified parameters of the three-dimensional two-state heat transfer model: Determining the surface temperature, ambient temperature, and heat transfer of each surface of the battery module to be evaluated; Based on the surface temperature, the ambient temperature, and the heat transfer amount of each surface, parameter identification is performed on the three-dimensional two-state heat transfer model to obtain first identified parameters of the three-dimensional two-state heat transfer model.

[0090] In an exemplary embodiment of the present invention, the construction module 510 may construct a three-dimensional two-state heat transfer model for the battery module to be evaluated in the following manner: In consideration of the maximum temperature and each surface temperature of the battery module to be evaluated, discretization processing is performed based on a three-dimensional heat transfer model to construct a three-dimensional two-state heat transfer model for the battery module to be evaluated.

[0091] In an exemplary embodiment of the present invention, the estimation module 530 may also be configured to: Performing equivalent processing on the battery module to be evaluated to obtain a Thevenin equivalent circuit model of the battery module corresponding to the battery module to be evaluated; Performing parameter identification on the Thevenin equivalent circuit model of the battery module to obtain second identified parameters; Substituting the second identified parameters into the Thevenin equivalent circuit model of the battery module to obtain a heat generation model of the battery module to be evaluated; Obtaining an average battery temperature of the battery module to be evaluated based on the maximum temperature of the battery module to be evaluated and the surface temperatures of each battery module to be evaluated; The energy efficiency of the battery module to be evaluated is determined based on the heat generation model and an average battery temperature of the battery module to be evaluated.

[0092] Figure 6 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 6 As shown, the electronic device may include: a processor 610, a communication interface 620, a memory 630 and a communication bus 640, wherein the processor 610, the communication interface 620 and the memory 630 communicate with each other through the communication bus 640. The processor 610 may call the logic instructions in the memory 630 to execute the maximum temperature estimation method of the battery module, the method comprising: constructing a three-dimensional two-state heat transfer model for the battery module to be evaluated, wherein the three-dimensional two-state heat transfer model is used to characterize the heat transfer model under the condition of considering the maximum temperature and each surface temperature of the battery module to be evaluated; performing parameter identification on the three-dimensional two-state heat transfer model to obtain the first identified parameter of the three-dimensional two-state heat transfer model, and substituting the first identified parameter into the three-dimensional two-state heat transfer model to obtain the target three-dimensional two-state heat transfer model; obtaining the total heat generation of the battery module to be evaluated in real time, and estimating the maximum temperature of the battery module to be evaluated based on the total heat generation and the target three-dimensional two-state heat transfer model.

[0093] In addition, the logic instructions in the above-mentioned memory 630 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0094] On the other hand, the present invention also provides a computer program product, which includes a computer program, which can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the maximum temperature estimation method of the battery module provided by the above-mentioned methods, and the method includes: constructing a three-dimensional two-state heat transfer model for the battery module to be evaluated, wherein the three-dimensional two-state heat transfer model is used to characterize the heat transfer model under the condition of considering the maximum temperature and each surface temperature of the battery module to be evaluated; performing parameter identification on the three-dimensional two-state heat transfer model to obtain a first identified parameter of the three-dimensional two-state heat transfer model, and substituting the first identified parameter into the three-dimensional two-state heat transfer model to obtain a target three-dimensional two-state heat transfer model; obtaining the total heat generation of the battery module to be evaluated in real time, and estimating the maximum temperature of the battery module to be evaluated based on the total heat generation and the target three-dimensional two-state heat transfer model.

[0095] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the maximum temperature estimation method of the battery module provided by the above-mentioned methods, the method comprising: constructing a three-dimensional two-state heat transfer model for the battery module to be evaluated, wherein the three-dimensional two-state heat transfer model is used to characterize the heat transfer model under the condition of considering the maximum temperature and each surface temperature of the battery module to be evaluated; performing parameter identification on the three-dimensional two-state heat transfer model to obtain a first identified parameter of the three-dimensional two-state heat transfer model, and substituting the first identified parameter into the three-dimensional two-state heat transfer model to obtain a target three-dimensional two-state heat transfer model; obtaining the total heat generation of the battery module to be evaluated in real time, and estimating the maximum temperature of the battery module to be evaluated based on the total heat generation and the target three-dimensional two-state heat transfer model.

[0096] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0097] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0098] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for estimating the maximum temperature of a battery module, characterized in that: The method comprises: Constructing a three-dimensional two-state heat transfer model for the battery module to be evaluated, wherein the three-dimensional two-state heat transfer model is used to characterize a heat transfer model under the condition of considering the maximum temperature and each surface temperature of the battery module to be evaluated; Performing parameter identification on the three-dimensional two-state heat transfer model to obtain first identified parameters of the three-dimensional two-state heat transfer model, and substituting the first identified parameters into the three-dimensional two-state heat transfer model to obtain a target three-dimensional two-state heat transfer model; The total heat generation of the battery module to be evaluated is acquired in real time, and the maximum temperature of the battery module to be evaluated is estimated based on the total heat generation and the target three-dimensional two-state heat transfer model.

2. The method for estimating the maximum temperature of a battery module according to claim 1, characterized in that: The estimating the maximum temperature of the battery module to be evaluated based on the total heat generation and the target three-dimensional two-state heat transfer model specifically includes: Based on the total heat generation, determining the amount of heat transferred on each surface of the battery module to be evaluated by transferring the total heat generation on each surface; Based on the heat transfer amount of each surface and the target three-dimensional two-state heat transfer model, estimating the maximum temperature in each surface dimension; Based on the maximum temperature in each surface dimension, the maximum temperature of the battery module to be evaluated is estimated.

3. The method for estimating the maximum temperature of a battery module according to claim 2, characterized in that: The estimating the maximum temperature of the battery module to be evaluated based on the maximum temperature in each surface dimension specifically includes: When the deviation between the maximum temperatures in each surface dimension is within a preset range, the maximum temperature of the battery module to be evaluated is estimated based on the average value of the maximum temperatures in each surface dimension; If the deviation between the maximum temperatures in each surface dimension is outside the preset range, the steps of redistributing the heat transfer of each surface to obtain the rear surface heat transfer after redistribution, and estimating the maximum temperature in each surface dimension based on the rear surface heat transfer after redistribution and the target three-dimensional two-state heat transfer model are repeated until the deviation between the maximum temperatures in each surface dimension is within the preset range, and the maximum temperature of the battery module to be evaluated is estimated based on the average value of the maximum temperatures in each surface dimension.

4. The method for estimating the maximum temperature of a battery module according to claim 3, characterized in that: Redistributing the heat transfer of each surface to obtain the heat transfer of the surface after redistribution is achieved in the following way: Sort the highest temperatures in each surface dimension from large to small to obtain a sorted sequence; Part of the surface heat transfer of the surface dimension ranked at the front preset number of the sorting sequence is distributed to the surface heat transfer of the surface dimension ranked at the back preset number of the sorting sequence.

5. The method for estimating the maximum temperature of a battery module according to claim 2, characterized in that: The determining, based on the total heat generation, the amount of heat transferred on each surface of the battery module to be evaluated by transferring the total heat generation on each surface specifically includes: The total heat generation is distributed according to the surface area of ​​each surface of the battery module to be evaluated to obtain the heat transfer amount of each surface where the total heat generation is transferred on each surface of the battery module to be evaluated.

6. The method for estimating the maximum temperature of a battery module according to any one of claims 1 to 5, characterized in that: Performing parameter identification on the three-dimensional two-state heat transfer model to obtain first identified parameters of the three-dimensional two-state heat transfer model is achieved in the following manner: Determining the surface temperature, ambient temperature, and heat transfer of each surface of the battery module to be evaluated; Based on the surface temperature, the ambient temperature, and the heat transfer amount of each surface, parameter identification is performed on the three-dimensional two-state heat transfer model to obtain first identified parameters of the three-dimensional two-state heat transfer model.

7. The method for estimating the maximum temperature of a battery module according to any one of claims 1 to 5, characterized in that: A three-dimensional two-state heat transfer model of the battery module to be evaluated is constructed in the following way: In consideration of the maximum temperature and each surface temperature of the battery module to be evaluated, discretization processing is performed based on a three-dimensional heat transfer model to construct a three-dimensional two-state heat transfer model for the battery module to be evaluated.

8. The method for estimating the maximum temperature of a battery module according to claim 1, characterized in that: After estimating the maximum temperature of the battery module to be evaluated, the method further includes: Performing equivalent processing on the battery module to be evaluated to obtain a Thevenin equivalent circuit model of the battery module corresponding to the battery module to be evaluated; Performing parameter identification on the Thevenin equivalent circuit model of the battery module to obtain second identified parameters; Substituting the second identified parameters into the Thevenin equivalent circuit model of the battery module to obtain a heat generation model of the battery module to be evaluated; Obtaining an average battery temperature of the battery module to be evaluated based on the maximum temperature of the battery module to be evaluated and the surface temperatures of each battery module to be evaluated; The energy efficiency of the battery module to be evaluated is determined based on the heat generation model and an average battery temperature of the battery module to be evaluated.

9. A device for estimating the maximum temperature of a battery module, characterized in that: The device comprises: A construction module, used to construct a three-dimensional two-state heat transfer model for the battery module to be evaluated, wherein the three-dimensional two-state heat transfer model is used to characterize a heat transfer model under the condition of considering the maximum temperature and each surface temperature of the battery module to be evaluated; an identification module, configured to perform parameter identification on the three-dimensional two-state heat transfer model to obtain first identified parameters of the three-dimensional two-state heat transfer model, and substitute the first identified parameters into the three-dimensional two-state heat transfer model to obtain a target three-dimensional two-state heat transfer model; The estimation module is used to obtain the total heat generation of the battery module to be evaluated in real time, and estimate the maximum temperature of the battery module to be evaluated based on the total heat generation and the target three-dimensional two-state heat transfer model.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the method for estimating the maximum temperature of the battery module according to any one of claims 1 to 8 is implemented.

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