Battery pulse current heating method, system, equipment and medium in low-temperature environment

Abstract

The invention discloses a battery pulse current heating method, system and device in a low-temperature environment and a medium, and the heating method comprises the steps: providing an initial pulse current for a second battery pack through a first battery pack based on an initial pulse duty ratio at a set environment temperature; calculating heat generated when the initial pulse current flows through the internal resistors of the first battery pack and the second battery pack based on a preset second-order equivalent circuit model; inputting the calculated heat into a lumped parameter thermal model to establish a curve of the temperature of the battery changing along with time; and by taking the pulse current amplitude and the pulse duty ratio as optimization variables and taking the minimization of the time required for the first battery pack and the second battery pack to reach the optimal working temperature as a target, performing rolling optimization on the lumped parameter thermal model and the second-order equivalent circuit model, and determining the optimal target pulse current and the optimal target pulse duty ratio. The invention aims to improve the heating efficiency and the performance reliability of the battery in a low-temperature environment.

Description

Technical Field

[0001] This application relates to the field of battery thermal management systems, specifically to a method, system, device, and medium for battery pulse current heating in low-temperature environments. Background Technology

[0002] Lithium-ion batteries are widely used in electric vehicles, portable electronic devices, and energy storage systems due to their high energy density and long cycle life. However, in low-temperature environments (e.g., below -20°C), the performance of lithium-ion batteries degrades significantly, manifesting as reduced capacity, increased internal resistance, and slower charging speed. These issues limit the application of lithium-ion batteries in cold climates or high-latitude regions.

[0003] To address these issues, existing technologies have proposed various thermal management strategies, including external heating systems (such as electric heaters), internal heating methods (such as continuous current self-heating), and phase change material (PCM) cooling / heating systems. However, these methods have the following limitations: (1) External heating systems: require additional heating elements, increasing system complexity and energy consumption, and have low heating efficiency. (2) Internal self-heating: generates heat through the continuous discharge / charge of the battery itself, but may lead to battery overheating or shortened lifespan. (3) Phase change materials: although they can provide uniform temperature control, their response speed is slow and they cannot quickly meet the requirements for low-temperature startup.

[0004] Therefore, improving the heating efficiency of batteries in low-temperature environments and ensuring battery performance reliability are urgent problems to be solved. Summary of the Invention

[0005] This application provides a method, system, device, and medium for heating batteries with pulse current in low-temperature environments, aiming to improve the heating efficiency of batteries in low-temperature environments and ensure the reliability of battery performance.

[0006] On one hand, embodiments of this application provide a method for heating a battery with pulsed current in a low-temperature environment. The battery includes a first battery pack and a second battery pack, wherein the low-temperature performance of the first battery pack is higher than that of the second battery pack. The heating method includes: at a set ambient temperature, providing an initial pulse current to the second battery pack through the first battery pack based on an initial pulse duty cycle to heat the second battery pack; determining the internal resistance of the first battery pack and the second battery pack in the current state based on a preset second-order equivalent circuit model, and calculating the heat generated when the initial pulse current flows through the internal resistance of the first battery pack and the second battery pack according to Joule's law; the second-order equivalent circuit... The model is used to simulate the electrical behavior of the first battery pack and the second battery pack. The calculated heat is input into a preset lumped parameter thermal model to establish a curve of the battery temperature changing over time. The lumped parameter thermal model is used to simulate the thermal behavior of the first battery pack and the second battery pack. Using the pulse current amplitude and pulse duty cycle as optimization variables, and minimizing the time required for both the first and second battery packs to reach their optimal operating temperatures as the objective, the lumped parameter thermal model and the second-order equivalent circuit model are subjected to rolling optimization to determine the optimal target pulse current and target pulse duty cycle, so as to heat the battery in a low-temperature environment based on the target pulse current and target pulse duty cycle.

[0007] Optionally, in some embodiments of this application, the expression for the lumped parameter thermal model is: , in, The battery mass is the mass of the battery. For specific heat capacity, For the rate of temperature rise, The pulse duty cycle is... The amplitude of the pulse current. The internal resistance of the battery is... The temperature of the battery, The convective heat transfer coefficient is... The surface area of ​​the battery is... The ambient temperature is mentioned.

[0008] Optionally, in some embodiments of this application, the heating method further includes: establishing the second-order equivalent circuit model, wherein the step of establishing the second-order equivalent circuit model specifically includes: applying a preset pulse current excitation to the battery through a hybrid pulse power characteristic test, and simultaneously acquiring voltage response data and current data at a preset temperature; based on the voltage response data and the current data, obtaining the open-circuit voltage measurement values ​​of the battery under different states of charge, and using a polynomial fitting method to establish a mapping function relationship between the states of charge and the open-circuit voltage measurement values; using the current data as input and the voltage response data as the desired output, and performing a multinomial fitting on the battery. The parameter set of the second-order equivalent circuit model is identified; the identified parameter set is configured in the second-order equivalent circuit model, and simulation is performed based on the preset pulse current to obtain the simulated terminal voltage data and state of charge simulation data of the battery; according to the state of charge simulation data and the mapping function relationship, the simulated open-circuit voltage value of the battery is calculated, and a simulation relationship curve between the simulated open-circuit voltage value and the corresponding state of charge simulation value in the state of charge simulation data is established; the simulation relationship curve is compared with the mapping function relationship to determine whether the consistency between the two reaches the preset accuracy standard, so as to verify the accuracy of the second-order equivalent circuit model.

[0009] Optionally, in some embodiments of this application, the step of performing rolling optimization on the lumped parameter thermal model and the second-order equivalent circuit model to determine the optimal target pulse current and target pulse duty cycle specifically includes: setting a pulse parameter set, the pulse parameter set including multiple pulse current amplitudes and multiple pulse duty cycles; inputting any pulse current amplitude and any pulse duty cycle from the pulse parameter set into the electro-thermal coupling model composed of the lumped parameter thermal model and the second-order equivalent circuit model, simulating to obtain the predicted temperature rise curves of the first battery pack and the second battery pack, and calculating the temperature rise curves of the first battery pack and the second battery pack based on the predicted temperature rise curves. The time required for both the first and second battery packs to reach their optimal operating temperatures, and the total energy consumption of the batteries during the heating cycle; based on the time required for both the first and second battery packs to reach their optimal operating temperatures and the total energy consumption, a fitness function value is calculated; based on the fitness function value and whether the safety constraints of battery voltage and state of charge are met, a new combination of the pulse current amplitude and the pulse duty cycle is continuously generated through an optimization algorithm until the improvement of the fitness function value is less than a preset threshold or the maximum number of iterations is reached, and the final obtained pulse current amplitude and pulse duty cycle are determined as the target pulse current and the target pulse duty cycle.

[0010] Optionally, in some embodiments of this application, the time required for both the first battery pack and the second battery pack to reach their optimal operating temperature is specified. The expression is: , in, This is the time required for both the first battery pack and the second battery pack to reach their optimal operating temperature. The amplitude of the pulse current. The pulse duty cycle is... The time it takes for the first battery pack to reach its optimal operating temperature. The time it takes for the second battery pack to reach its optimal operating temperature; The total energy consumption The expression is: , , in, The power of the pulse current provided to the first battery pack. It is the instantaneous voltage of the first battery pack. The amplitude of the pulse current. For time step, The pulse state within a certain time step; The expression for the fitness function value is: , in, The amplitude of the pulse current. The pulse duty cycle is... This is the time required for both the first battery pack and the second battery pack to reach their optimal operating temperature. The total energy consumption is mentioned above. They are in balance and The weight.

[0011] Optionally, in some embodiments of this application, the heating method further includes: monitoring the terminal voltage and / or state of charge of the first battery pack and the second battery pack in real time based on the second-order equivalent circuit model; if the terminal voltage of either the first battery pack or the second battery pack exceeds a safe operating window or the state of charge is lower than a preset threshold, then interrupting the provision of the initial pulse current.

[0012] Optionally, in some embodiments of this application, the optimal operating temperature of the first battery pack and the optimal operating temperature of the second battery pack are both in the range of 15°C to 35°C.

[0013] On the other hand, this application provides a battery pulse current heating system for low-temperature environments, comprising: a first battery pack, a second battery pack, a battery management module, and a control circuit; the low-temperature performance of the first battery pack is higher than that of the second battery pack; the battery management module is configured to establish a lumped parameter thermal model to simulate the thermal behavior of the first battery pack and the second battery pack, and to establish a second-order equivalent circuit model to simulate the electrical behavior of the first battery pack and the second battery pack; the control circuit is electrically connected to the first battery pack and the second battery pack respectively, and is used to control the first battery pack to provide pulse current to the second battery pack with a specific pulse duty cycle based on the instructions issued by the battery management module; the battery management module is also configured to control the control circuit based on an initial pulse duty cycle and an initial pulse current at a set ambient temperature. Heating is achieved using an electric current. Based on the second-order equivalent circuit model, the internal resistances of the first and second battery packs in the current state are determined, and the heat generated when the pulse current flows through the internal resistances of the first and second battery packs is calculated according to Joule's law. The calculated heat is then input into the lumped parameter thermal model to predict the temperature change curve of the battery over time. Furthermore, using the pulse current amplitude and pulse duty cycle as optimization variables, and minimizing the time required for both the first and second battery packs to reach their optimal operating temperatures, rolling optimization is performed on the lumped parameter thermal model and the second-order equivalent circuit model to determine the optimal target pulse current and target pulse duty cycle. This allows for heating of the battery in a low-temperature environment based on the target pulse current and target pulse duty cycle.

[0014] On the other hand, this application provides an electronic device including a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor executes the computer program to implement the battery pulse current heating method in a low-temperature environment as described above.

[0015] On the other hand, this application provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the battery pulse current heating method in a low-temperature environment as described above.

[0016] The battery pulse current heating method, system, device, and medium provided in this application for low-temperature environments utilize a first battery pack with excellent low-temperature performance to provide pulse current to a second battery pack with poor low-temperature performance, thereby simultaneously achieving rapid self-heating of both the first and second battery packs. At the same time, by optimizing the amplitude and duty cycle of the pulse current, it ensures that both the first and second battery packs reach their respective optimal operating temperatures in the shortest possible time. This improves the heating efficiency of the battery in low-temperature environments while reducing the need for external heating equipment and ensuring the reliability of battery performance. Attached Figure Description

[0017] Figure 1 This is a flowchart of the battery pulse current heating method in a low-temperature environment provided in this application; Figure 2 This is a circuit diagram of the second-order equivalent circuit model provided in this application; Figure 3 This is the SOC-OCV relationship diagram obtained experimentally in the battery pulse current heating method for low-temperature environments provided in this application; Figure 4 This is a simulation diagram showing the change of the open-circuit voltage (OCV) of the battery over time in the battery pulse current heating method provided in this application at low temperature. Figure 5 This is a schematic diagram of the battery pulse current heating system provided in this application for low-temperature environments. Detailed Implementation

[0018] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings. The described technical solutions are for illustrative purposes only and should not be construed as limiting the scope of protection of this application.

[0019] like Figure 1 As shown, an embodiment of this application provides a method for heating a battery with pulsed current in a low-temperature environment. The battery includes a first battery pack and a second battery pack, wherein the low-temperature performance of the first battery pack is higher than that of the second battery pack. Specifically, the first battery pack has a capacity retention rate of ≥80% at -30°C, and the second battery pack has a capacity retention rate of ≤80% at -30°C. Preferably, the first battery pack is a sodium-ion battery, which has the characteristic of maintaining high capacity and fast charging capability at low temperatures. The second battery pack is a lithium-ion battery, whose performance typically degrades significantly below -20°C.

[0020] Specifically, the battery pulse current heating method in low-temperature environments includes: S10. At a set ambient temperature, the first battery pack provides an initial pulse current to the second battery pack based on the initial pulse duty cycle to heat the second battery pack.

[0021] Specifically, the first and second battery packs are connected via a control circuit that includes switching elements for generating and controlling pulsed currents from the first to the second battery pack. The circuit design allows the first battery pack to act as the primary power source in low-temperature environments, supplying pulsed currents to the second battery pack while simultaneously generating heat through its internal resistance.

[0022] The low-temperature battery pulse current heating method provided in this application utilizes a first battery pack (such as a sodium-ion battery) with excellent low-temperature performance as a pulse source to directly heat the internal resistance of a second battery pack (such as a lithium-ion battery), resulting in a short energy utilization path and high efficiency. By optimizing the algorithm to precisely control the pulse parameters, extremely high heating efficiency is achieved. This significantly improves the driving range and starting speed of electric vehicles in low-temperature environments.

[0023] S20. Based on the preset second-order equivalent circuit model, determine the internal resistance of the first battery pack and the second battery pack in the current state, and calculate the heat generated when the initial pulse current flows through the internal resistance of the first battery pack and the second battery pack according to Joule's law. The second-order equivalent circuit model is used to simulate the electrical behavior of the first battery pack and the second battery pack.

[0024] Specifically, the heating process is based on the Joule heating principle. When the first battery pack provides a pulsed current to the second battery pack, the current generates heat as it flows through the internal resistance of both packs, causing the temperature to rise. The intermittent nature of the pulsed current (compared to continuous current) reduces the risk of battery overheating, improves heating uniformity, and minimizes the impact on battery life.

[0025] Specifically, a second-order equivalent circuit model is established to simulate the electrical behavior of the first and second battery packs.

[0026] like Figure 2 As shown, the second-order equivalent circuit model includes: an open-circuit voltage source (OCV), a series resistor (R0, representing the ohmic resistance), and two parallel RC branches (R1C1 and R2C2, representing electrochemical polarization and concentration polarization).

[0027] In embodiments of this application, the heating method further includes: establishing a second-order equivalent circuit model.

[0028] The specific steps for establishing a second-order equivalent circuit model include: S201. Through hybrid pulse power characteristic test, a preset pulse current excitation is applied to the battery, and voltage response data and current data at a preset temperature are collected simultaneously.

[0029] S202. Based on voltage response data and current data, obtain the open-circuit voltage measurement values ​​of the battery under different states of charge, and establish a mapping function relationship between the state of charge and the open-circuit voltage measurement values ​​using a polynomial fitting method. Figure 3 This is a curve showing the relationship between the battery's state of charge and its measured open-circuit voltage.

[0030] S203. Using current data as input and voltage response data as the desired output, identify the parameter set of the second-order equivalent circuit model.

[0031] S204. Configure the identified parameter group in the second-order equivalent circuit model, and perform simulation based on the preset pulse current to obtain the battery terminal voltage simulation data and state of charge simulation data.

[0032] S205. Based on the state of charge simulation data and the mapping function relationship, calculate the simulated value of the open-circuit voltage of the battery, and establish a simulation relationship curve between the simulated value of the open-circuit voltage and the corresponding simulated value of the state of charge in the state of charge simulation data.

[0033] Figure 4 The simulation results show the change of the battery's open-circuit voltage over time.

[0034] S206. Compare the simulation relationship curve with the mapping function relationship to determine whether the consistency between the two reaches the preset accuracy standard, so as to verify the accuracy of the second-order equivalent circuit model.

[0035] In embodiments of this application, the heating method further includes the following steps: Based on a second-order equivalent circuit model, the terminal voltage and / or state of charge of the first and second battery packs are monitored in real time.

[0036] If the terminal voltage of either the first battery pack or the second battery pack exceeds the safe operating window or the state of charge is lower than a preset threshold, the supply of the initial pulse current will be interrupted.

[0037] Traditional self-heating or external heating methods can easily lead to large temperature differences (typically >8°C) inside and between batteries, accelerating battery aging and posing a risk of thermal runaway. The low-temperature battery pulse current heating method provided in this application ensures temperature uniformity during the heating process by optimizing the intermittent characteristics of the pulse current (pulse duty cycle) and the dual-core synergistic heat generation mechanism. Actual measurement data shows that the maximum temperature difference between dual-core batteries can be controlled within 3°C, and the internal temperature difference of individual battery cells is less than 5°C. This excellent temperature uniformity effectively avoids localized overheating and lithium deposition, significantly extending the cycle life of the battery system and fundamentally improving the safety of the low-temperature heating process.

[0038] S30. Input the calculated heat into the preset lumped parameter thermal model to establish the temperature change curve of the battery over time. The lumped parameter thermal model is used to simulate the thermal behavior of the first battery pack and the second battery pack.

[0039] Specifically, a lumped parameter thermal model is established to simulate the thermal behavior of the first and second battery packs.

[0040] In the embodiments of this application, the lumped parameter thermal model treats the battery as a thermal mass, mainly considering the following factors: the heat generated by Joule heating, the heat transfer between the battery and the environment (through convection heat transfer), and the battery's thermal capacity and thermal conductivity.

[0041] In the embodiments of this application, the expression for the lumped parameter thermal model is: , in, For the battery's quality, For specific heat capacity, For the rate of temperature rise, The pulse duty cycle. The amplitude of the pulse current. The internal resistance of the battery. For the temperature of the battery, The convective heat transfer coefficient is... The surface area of ​​the battery. The ambient temperature.

[0042] S40. Using the pulse current amplitude and pulse duty cycle as optimization variables, and minimizing the time required for both the first and second battery packs to reach their optimal operating temperatures, rolling optimization is performed on the lumped parameter thermal model and the second-order equivalent circuit model to determine the optimal target pulse current and target pulse duty cycle, so as to heat the battery in a low-temperature environment based on the target pulse current and target pulse duty cycle.

[0043] In the embodiments of this application, optimization algorithms such as particle swarm optimization (PSO) or genetic algorithm (GA) are used to search for optimal pulse parameters (pulse current amplitude I and pulse duty cycle D).

[0044] In the embodiments of this application, the step of performing rolling optimization on the lumped parameter thermal model and the second-order equivalent circuit model to determine the optimal target pulse current and target pulse duty cycle includes: S401. Set the pulse parameter set, which includes multiple pulse current amplitudes and multiple pulse duty cycles.

[0045] S402. Input any pulse current amplitude and any pulse duty cycle from the pulse parameter set into the electro-thermal coupling model composed of the lumped parameter thermal model and the second-order equivalent circuit model, simulate to obtain the predicted temperature rise curves of the first battery pack and the second battery pack, and calculate the time required for the first battery pack and the second battery pack to reach their optimal operating temperature, as well as the total energy consumption of the battery during the heating cycle, based on the predicted temperature rise curves.

[0046] By optimizing the amplitude and duty cycle of the pulse current, and heating the battery based on the target pulse current and target duty cycle in a low-temperature environment, the battery can raise the temperature of the first and second battery packs to their respective optimal operating ranges in the shortest possible time.

[0047] In the embodiments of this application, the optimal operating temperature range for both the first battery pack and the second battery pack is 15°C to 35°C. Specifically, the optimal operating temperatures for both the first and second battery packs include 15°C, 16°C, 17°C, 18°C, 19°C, 20°C, 21°C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C, and 35°C. Preferably, the optimal operating temperature for the second battery pack is 25°C.

[0048] In the embodiments of this application, the amplitude range of the pulse current is 0 to 5 times the rated capacity of the battery. Specifically, the amplitude of the pulse current includes 0 times, 1 times, 2 times, 3 times, 4 times, and 5 times the rated capacity of the battery. For example, for a battery with a capacity of 100Ah, the pulse current corresponding to 1C is 100A. Then, the pulse current corresponding to 5C is 500A.

[0049] In the embodiments of this application, the state of charge (SOC) of both the first battery pack and the second battery pack ranges from 10% to 90% of their rated capacity. Specifically, the SOC values ​​of both the first battery pack and the second battery pack are 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90% of their rated capacity.

[0050] In the embodiments of this application, the time required for both the first battery pack and the second battery pack to reach their optimal operating temperature is specified. The expression is: , in, This refers to the time required for both the first and second battery packs to reach their optimal operating temperature. The amplitude of the pulse current. The pulse duty cycle. The time it takes for the first battery pack to reach its optimal operating temperature. The time it takes for the second battery pack to reach its optimal operating temperature.

[0051] In the embodiments of this application, the time required for both the first battery pack and the second battery pack to reach their optimal operating temperature is specified. The constraints of the objective function to be minimized include the maximum allowable temperature, the maximum pulse current, and the battery state of charge.

[0052] Total energy consumption The expression is: , , in, The power of the pulse current provided to the first battery pack. It is the instantaneous voltage of the first battery pack. The amplitude of the pulse current. For time step, It represents the pulse state within a certain time step.

[0053] S403. Calculate the fitness function value based on the time required for both the first and second battery packs to reach their optimal operating temperatures and the total energy consumption.

[0054] The expression for the fitness function value is: , in, The amplitude of the pulse current. The pulse duty cycle. This refers to the time required for both the first and second battery packs to reach their optimal operating temperature. Total energy consumption They are in balance and The weight.

[0055] S404. Based on the fitness function value and whether the safety constraints of battery voltage and state of charge are met, new combinations of pulse current amplitude and pulse duty cycle are continuously generated through optimization algorithms until the improvement of the fitness function value is less than the preset threshold or the maximum number of iterations is reached. The final pulse current amplitude and pulse duty cycle are then determined as the target pulse current and target pulse duty cycle.

[0056] The battery pulse current heating method for low-temperature environments provided in this application utilizes a first battery pack with excellent low-temperature performance to provide a pulse current to a second battery pack with poor low-temperature performance, thereby simultaneously achieving rapid self-heating of both the first and second battery packs. At the same time, by optimizing the amplitude and duty cycle of the pulse current, it ensures that both the first and second battery packs reach their respective optimal operating temperatures in the shortest possible time. This improves the heating efficiency of the battery in low-temperature environments while reducing the need for external heating equipment and ensuring the reliability of battery performance.

[0057] like Figure 5 As shown, this application provides a battery pulse current heating system for low-temperature environments, including: a first battery pack 10, a second battery pack 20, a battery management module 30, and a control circuit 40.

[0058] Specifically, the low-temperature performance of the first battery pack 10 is higher than that of the second battery pack 20. The first battery pack 10 has a capacity retention rate of ≥80% at -30℃, while the second battery pack 20 has a capacity retention rate of ≤80% at -30℃. Preferably, the first battery pack 10 is a sodium-ion battery, which has the characteristic of maintaining high capacity and fast charging capability at low temperatures. The second battery pack 20 is a lithium-ion battery, whose performance typically degrades significantly below -20℃.

[0059] Specifically, the battery management module 30 is configured to establish a lumped parameter thermal model to simulate the thermal behavior of the first battery pack 10 and the second battery pack 20, and to establish a second-order equivalent circuit model to simulate the electrical behavior of the first battery pack 10 and the second battery pack 20.

[0060] Specifically, the control circuit 40 is electrically connected to the first battery pack 10 and the second battery pack 20 respectively, and is used to control the first battery pack 10 to provide pulse current to the second battery pack 20 with a specific pulse duty cycle based on the instructions issued by the battery management module 30.

[0061] Specifically, the battery management module 30 is also configured to control the control circuit 40 to heat the battery based on the initial pulse duty cycle and the initial pulse current at a set ambient temperature. Based on the second-order equivalent circuit model, the internal resistance of the first battery pack 10 and the second battery pack 20 in the current state is determined respectively. The heat generated when the pulse current flows through the internal resistance of the first battery pack 10 and the second battery pack 20 is calculated according to Joule's law. The calculated heat is then input into the lumped parameter thermal model to predict the curve of the battery temperature changing over time.

[0062] Specifically, the battery management module 30 is further configured to perform rolling optimization on the lumped parameter thermal model and the second-order equivalent circuit model with the pulse current amplitude and pulse duty cycle as optimization variables, and with the goal of minimizing the time required for both the first battery pack 10 and the second battery pack 20 to reach their optimal operating temperature, to determine the optimal target pulse current and target pulse duty cycle, so as to heat the battery based on the target pulse current and target pulse duty cycle in a low-temperature environment, and control the control circuit 40 to execute.

[0063] Specifically, the heating system also includes a temperature sensor 50 for real-time monitoring of the temperatures of the first battery pack 10 and the second battery pack 20.

[0064] The low-temperature environment battery pulse current heating system provided in this application utilizes a first battery pack 10 with excellent low-temperature performance to provide a pulse current to a second battery pack 20 with poor low-temperature performance, thereby simultaneously achieving rapid self-heating of both the first battery pack 10 and the second battery pack 20. At the same time, by optimizing the amplitude and duty cycle of the pulse current, it ensures that both the first battery pack 10 and the second battery pack 20 can reach their respective optimal operating temperatures in the shortest possible time. This improves the heating efficiency of the battery in low-temperature environments while reducing the need for external heating equipment and ensuring the reliability of battery performance.

[0065] The low-temperature battery pulse current heating system provided in this application eliminates the need for additional external heating elements (such as PTC heating films), fully utilizing the existing dual-core battery architecture and the computing power of the BMS (Battery Management Module 30) for pulse control and optimization. This not only reduces system complexity, weight, and manufacturing costs but also saves valuable internal space within the battery pack. The entire solution is a highly efficient, low-cost, and integrated thermal management solution.

[0066] The battery pulse current heating system for low-temperature environments provided in this application uses the battery pulse current heating method for low-temperature environments provided in this application as described above to heat the battery. The specific steps will not be repeated here.

[0067] On the other hand, this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor executes the computer program to implement the above-mentioned battery pulse current heating method in a low-temperature environment.

[0068] On the other hand, this application provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the above-described battery pulse current heating method in a low-temperature environment.

[0069] The above provides a detailed description of a battery pulse current heating method, system, device, and medium in a low-temperature environment as described in the embodiments of this application. The description of the above embodiments is only for the purpose of helping to understand the core idea of ​​this application, and the above description should not be construed as a limitation on the scope of protection of this application.

Claims

1. A method for battery pulse current heating in a cryogenic environment, characterized by, The battery comprises a first battery pack and a second battery pack, the low-temperature performance of the first battery pack is higher than that of the second battery pack, and the heating method comprises: providing an initial pulse current to the second battery pack based on an initial pulse duty ratio of the first battery pack to heat the second battery pack at a set ambient temperature; determining internal resistances of the first battery pack and the second battery pack at a current state based on a preset second-order equivalent circuit model, and calculating heat generated when the initial pulse current flows through the internal resistances of the first battery pack and the second battery pack according to Joule's law, wherein the second-order equivalent circuit model is used to simulate electrical behavior of the first battery pack and the second battery pack; inputting the calculated heat into a preset lumped parameter thermal model to establish a curve of temperature change of the battery over time, wherein the lumped parameter thermal model is used to simulate thermal behavior of the first battery pack and the second battery pack; performing rolling optimization on the lumped parameter thermal model and the second-order equivalent circuit model by taking pulse current amplitude and pulse duty ratio as optimization variables and minimizing the time required for the first battery pack and the second battery pack to reach their optimal working temperatures as an objective, to determine optimal target pulse current and target pulse duty ratio for heating the battery in a low-temperature environment based on the target pulse current and the target pulse duty ratio.

2. The method of claim 1, wherein, The expression of the lumped parameter thermal model is: ， wherein, is a battery mass of the battery, is a specific heat capacity, is a temperature rise rate, is a pulse duty cycle, is a pulse current amplitude, is an internal resistance of the battery, is a temperature of the battery, is a convective heat transfer coefficient, is a surface area of the battery, is an ambient temperature.

3. The method of claim 1, wherein the battery pulse current heating is performed in a cryogenic environment. The heating method further comprises: establishing the second-order equivalent circuit model, the step of establishing the second-order equivalent circuit model specifically comprises: applying a preset pulse current excitation to the battery through a hybrid pulse power characteristic test, and synchronously collecting voltage response data and current data at a preset temperature; based on the voltage response data and the current data, obtaining open-circuit voltage measurement values of the battery at different states of charge, and establishing a mapping function relationship between the state of charge and the open-circuit voltage measurement values by using a polynomial fitting method; identifying a parameter set of the second-order equivalent circuit model by taking the current data as input and the voltage response data as expected output; configuring the identified parameter set in the second-order equivalent circuit model, and performing simulation based on a preset pulse current to obtain end voltage simulation data and state of charge simulation data of the battery; calculating open-circuit voltage simulation values of the battery according to the state of charge simulation data and the mapping function relationship, and establishing a simulation relationship curve between the open-circuit voltage simulation values and corresponding state of charge simulation values in the state of charge simulation data; 4. The method of claim 1, wherein, comparing the simulation relationship curve with the mapping function relationship to determine whether the consistency reaches a preset accuracy standard, to verify the accuracy of the second-order equivalent circuit model. The step of performing rolling optimization on the lumped parameter thermal model and the second-order equivalent circuit model to determine optimal target pulse current and target pulse duty ratio specifically comprises: setting a pulse parameter set, wherein the pulse parameter set comprises a plurality of pulse current amplitudes and a plurality of pulse duty ratios; inputting any of the pulse current amplitudes in the pulse parameter set and any of the pulse duty cycles into an electro-thermal coupling model constituted by the lumped parameter thermal model and the second-order equivalent circuit model, simulating to obtain a predicted temperature rise curve of the first battery pack and the second battery pack, and calculating a time required for the first battery pack and the second battery pack to reach their optimal working temperatures and a total energy consumption of the battery in a heating period according to the predicted temperature rise curve; calculating a fitness function value according to the time required for the first battery pack and the second battery pack to reach their optimal working temperatures and the total energy consumption; generating a new combination of the pulse current amplitude and the pulse duty cycle through an optimization algorithm according to the fitness function value and whether a safety constraint of battery voltage and state of charge is met, until an improvement amount of the fitness function value is less than a preset threshold or a maximum iteration number is reached, and determining the pulse current amplitude and the pulse duty cycle finally obtained as the target pulse current and the target pulse duty cycle.

5. The method of claim 4, wherein the battery pulse current heating is performed in a cryogenic environment. the time required for both the first battery pack and the second battery pack to reach their optimal operating temperature The expression is: ， wherein, is the time required for both the first battery and the second battery to reach their optimal operating temperature, is the pulse current amplitude, is the pulse duty cycle, is the time for the first battery to reach optimal operating temperature, is the time for the second battery to reach optimal operating temperature; the total energy consumption The expression for the total energy consumption is: ， ， wherein, a power of the pulsed current provided to the first battery pack, is an instantaneous voltage of the first battery pack, is a pulse current amplitude, is a time step, is a pulse state within a certain time step; An expression of the fitness function value is: ， wherein, is the pulse current amplitude, is the pulse duty cycle, is the time required for both the first and second battery packs to reach their optimal operating temperature, is the total energy consumption, are the weights of the balance and respectively.

6. The battery pulse current heating method in a cryogenic environment according to claim 1 or 4, wherein, The heating method further includes: monitoring an end voltage and / or a state of charge of the first battery pack and the second battery pack in real time based on the second-order equivalent circuit model; if the end voltage of any of the first battery pack and the second battery pack exceeds a safety working window or the state of charge is lower than a preset threshold, interrupting the provision of the initial pulse current.

7. The method of claim 1, wherein the battery pulse current heating is performed in a cryogenic environment. The optimal working temperature of the first battery pack and the optimal working temperature of the second battery pack are both in a range of 15°C to 35°C.

8. A battery pulse current heating system in a cryogenic environment, characterized by, It includes: a first battery pack, a second battery pack, a battery management module, and a control circuit; The low-temperature performance of the first battery pack is higher than that of the second battery pack. The battery management module is configured to establish a lumped parameter thermal model for simulating thermal behavior of the first battery pack and the second battery pack and establish a second-order equivalent circuit model for simulating electrical behavior of the first battery pack and the second battery pack. The control circuit is electrically connected with the first battery pack and the second battery pack respectively, and is configured to control the first battery pack to provide a pulse current to the second battery pack at a specific pulse duty cycle based on an instruction issued by the battery management module. The battery management module is further configured to control the control circuit to heat based on an initial pulse duty cycle and an initial pulse current at a set environment temperature, determine internal resistances of the first battery pack and the second battery pack in a current state respectively based on the second-order equivalent circuit model, and calculate heat generated when the pulse current flows through the internal resistances of the first battery pack and the second battery pack respectively according to Joule's law, and input the calculated heat into the lumped parameter thermal model to predict a curve of temperature change of the battery over time. and performing rolling optimization on the lumped parameter thermal model and the second-order equivalent circuit model with pulse current amplitude and pulse duty cycle as optimization variables, and with the time required for the first battery pack and the second battery pack to reach their optimal working temperatures as the optimization target, to determine optimal target pulse current and target pulse duty cycle for heating the battery in the low-temperature environment based on the target pulse current and the target pulse duty cycle.

9. An electronic device comprising a memory, a processor, and a computer program stored on the memory and running on the processor, characterized in that, The processor implements the low-temperature environment battery pulse current heating method as claimed in any one of claims 1 to 7 when executing the computer program.

10. A non-transitory computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program, when executed by the processor, implements the low-temperature environment battery pulse current heating method as claimed in any one of claims 1 to 7.

Images