A power battery low-temperature heating method and device and a new energy vehicle

Abstract

The application discloses a power battery low-temperature heating method and device and a new energy vehicle. The method comprises the following steps: acquiring battery state parameters, environmental temperature parameters and working state parameters of a heating related module of a power battery pack; determining the lowest temperature of a single battery cell according to the temperature of each single battery cell in the battery state parameters, and determining a target heating mode based on the relationship between the lowest temperature of the single battery cell and a preset temperature threshold, wherein the target heating mode comprises a heating mode in which pulse self-heating parameters and heat pump heating parameters work cooperatively; and dynamically adjusting the pulse heating parameters and the heat pump heating parameters of the target heating mode based on the battery state parameters and the environmental temperature parameters, so as to perform low-temperature heating on the power battery pack.

Description

Technical Field

[0001] This invention relates to the field of power battery thermal management technology, and in particular to a method, apparatus and new energy vehicle for low-temperature heating of power batteries. Background Technology

[0002] Power batteries are core components in new energy vehicles and energy storage devices, and their performance, charge and discharge efficiency, and lifespan are closely related to temperature. In low-temperature environments, the internal electrochemical reaction rate of power batteries decreases, the internal resistance of the battery increases, and problems such as reduced usable capacity, limited charge and discharge power, difficulty in low-temperature start-up, and reduced charging efficiency are likely to occur. In severe cases, it may also lead to safety risks such as lithium plating.

[0003] Existing methods for heating power batteries at low temperatures mainly include external heating and internal heating. External heating methods typically employ PTC heating, liquid cooling circulation heating, or heating film heating, which have the advantage of relatively simple control, but suffer from problems such as high energy consumption, slow heating rate, and uneven heat transfer. Internal heating methods usually utilize pulsed current or alternating charge-discharge methods to generate heat based on the internal resistance of the battery cell, resulting in a faster heating rate. However, improper control can easily lead to problems such as large temperature differences between individual cells, localized overheating, or excessive power consumption.

[0004] In addition, existing heating strategies mostly control the start and stop of heating based on a single temperature threshold, lacking a comprehensive judgment of battery status, ambient temperature, temperature difference of individual cells, SOC, SOH, and the working status of heating-related modules. It is difficult to dynamically adjust the heating mode and heating parameters according to different low temperature levels, which can easily lead to problems such as insufficient heating, overheating, or low energy utilization. Summary of the Invention

[0005] Based on this, it is necessary to provide a method, device, and new energy vehicle for low-temperature heating of power batteries to address the above-mentioned technical problems, so as to balance heating efficiency, energy consumption control, temperature uniformity, and heating safety, and achieve rapid, uniform, energy-saving, and safe heating of power battery packs in low-temperature environments.

[0006] One aspect of the present invention provides a method for low-temperature heating of a power battery, comprising the following steps: Obtain the battery status parameters, ambient temperature parameters, and operating status parameters of the heating-related modules of the power battery pack; The minimum temperature of each individual cell is determined based on the temperature of each individual cell in the battery state parameters. Based on the relationship between the minimum temperature of the individual cell and a preset temperature threshold, a target heating mode is determined. The target heating mode includes a heating mode with pulse self-heating parameters and heat pump heating parameters working in tandem. Based on the battery state parameters and the ambient temperature parameters, the pulse heating parameters and the heat pump heating parameters of the target heating mode are dynamically adjusted to heat the power battery pack at low temperatures.

[0007] Optionally, the step of determining the minimum temperature of a single cell based on the temperature of each individual cell in the battery state parameters, and determining the target heating mode based on the relationship between the minimum temperature of the single cell and a preset temperature threshold, further includes: Monitor the operating status of the heat pump system, pulse heating module, and waste heat recovery module; When the heat pump system, the pulse heating module, and the waste heat recovery module are all in normal working condition, the minimum temperature of each individual battery cell is determined based on the temperature of each individual battery cell, and the target heating mode is determined based on the relationship between the minimum temperature of the individual battery cell and the preset temperature threshold.

[0008] Optionally, determining the minimum temperature of a single cell based on the temperature of each individual cell in the battery state parameters, and determining the target heating mode based on the relationship between the minimum temperature of the single cell and a preset temperature threshold, includes: When the lowest temperature of the single cell is less than the first preset temperature threshold, the target heating mode is determined to be the first heating mode. In the first heating mode, the power battery pack is heated mainly by pulse self-heating and supplemented by heat pump heating. When the lowest temperature of the single cell is greater than or equal to the first preset temperature threshold and less than the second preset temperature threshold, the target heating mode is determined to be the second heating mode. In the second heating mode, the power battery pack is heated by pulse self-heating and heat pump heating in synergy. When the lowest temperature of the single cell is greater than or equal to the second preset temperature threshold and less than the third preset temperature threshold, the target heating mode is determined to be the third heating mode. In the third heating mode, the power battery pack is heated mainly by heat pump heating and supplemented by pulse self-heating. When the lowest temperature of the single cell is greater than or equal to the third preset temperature threshold, the target heating mode is determined to be the fourth heating mode. In the fourth heating mode, the power battery pack is controlled to stop low-temperature heating and enter the normal thermal management mode.

[0009] Optionally, the battery state parameters include at least one of the following: temperature of each individual cell in the power battery pack, total voltage of the power battery pack, state of charge (SOC), and state of health (SOH). The step of dynamically adjusting the pulse heating parameters and the heat pump heating parameters of the target heating mode based on the battery state parameters and the ambient temperature parameters includes: The pulse frequency and current amplitude of the pulse heating module are determined based on the lowest temperature of the individual battery cell, the state of charge (SOC), and the battery health (SOH). When the minimum temperature of the single cell decreases and the state of charge (SOC) meets the preset charge condition, the pulse frequency and / or the current amplitude are increased. When the lowest temperature of the single cell approaches the preset heating stop condition, or the state of charge (SOC) is lower than the preset limit threshold, the pulse frequency and / or the current amplitude are reduced. The pulse heating module controls at least two sets of cells in the power battery pack to charge and discharge alternately, enabling the power battery pack to achieve self-heating based on the heat generated by the internal resistance of the cells.

[0010] Optionally, determining the pulse frequency and current amplitude of the pulse heating module based on the lowest temperature of the individual battery cell, the state of charge (SOC), and the battery health (SOH) further includes: The temperature difference between the highest and lowest temperatures of a single battery cell is determined based on the temperature of each individual battery cell. When the temperature difference of the battery cells is greater than a preset temperature difference threshold, the pulse current amplitude corresponding to the battery cell group with lower temperature is increased, and / or the pulse current amplitude corresponding to the battery cell group with higher temperature is decreased. Differential heating control is applied to different cell groups based on the adjusted pulse current amplitude, so that the temperature difference between individual cells in the power battery pack is reduced to the target temperature difference range.

[0011] Optionally, the step of dynamically adjusting the pulse heating parameters and the heat pump heating parameters of the target heating mode based on the battery state parameters and the ambient temperature parameters further includes: The target heating power of the heat pump system is determined based on the ambient temperature parameters and the difference between the lowest temperature of the individual battery cell and the preset stop temperature threshold. When the ambient temperature decreases and / or the difference between the lowest temperature of the individual battery cell and the preset stop temperature threshold increases, the target heating power of the heat pump system is increased. When the lowest temperature of the individual battery cell approaches the preset stop temperature threshold, the target heating power of the heat pump system is reduced to suppress overheating.

[0012] Optionally, the method further includes: Obtain the waste heat temperature of at least one heat source component in the vehicle motor, electronic control module, braking system, or energy storage inverter; When the waste heat temperature is greater than the preset waste heat recovery temperature threshold, the waste heat recovery module is activated, and the waste heat generated by the heat source component is transferred to the power battery pack through the heat exchanger and circulation pipeline. Based on the waste heat temperature and the heating requirements of the power battery pack, adjust the opening of the three-way valve to distribute the waste heat to the power battery pack and / or the cabin heating circuit. When the waste heat temperature is not greater than the preset waste heat recovery temperature threshold, the waste heat recovery module is turned off, or the waste heat supply ratio of the waste heat recovery module is reduced.

[0013] Optionally, the battery state parameters include at least one of the following: temperature of each individual cell in the power battery pack, total voltage of the power battery pack, state of charge (SOC), and state of health (SOH). The method further includes: During the heating process, at least one of the following is monitored: temperature of each individual cell, battery pack voltage, battery pack current, state of charge (SOC), battery health (SOH), pulse heating module operating parameters, heat pump system operating parameters, and waste heat recovery module operating parameters. When the minimum temperature of the single cell reaches the preset stop temperature threshold, at least one of the pulse heating module, the heat pump system, and the waste heat recovery module is stopped. When at least one of the following abnormal conditions is detected: abnormal increase in temperature of a single cell, abnormal fluctuation in battery pack voltage, abnormal fluctuation in battery pack current, or failure of heating-related modules, low-temperature heating is stopped, an alarm signal is generated, and fault information is recorded. When the state of charge (SOC) is lower than a preset low charge threshold, the pulse heating module is stopped or limited, while heat pump heating and / or waste heat recovery heating are retained. When the temperature of each individual battery cell reaches the preset target temperature range, the battery pack enters the heat preservation mode to maintain the temperature of the power battery pack within the preset heat preservation temperature range.

[0014] In another aspect, the present invention provides a low-temperature heating device for a power battery, the device comprising: The parameter acquisition unit is used to acquire the battery status parameters, ambient temperature parameters, and working status parameters of the heating-related modules of the power battery pack. A heating mode determination unit is used to determine the minimum temperature of a single cell based on the temperature of each cell in the battery state parameters, and to determine a target heating mode based on the relationship between the minimum temperature of the single cell and a preset temperature threshold. The target heating mode includes a heating mode with pulse self-heating parameters and heat pump heating parameters working together. The parameter adjustment unit is used to dynamically adjust the pulse heating parameters and the heat pump heating parameters of the target heating mode based on the battery state parameters and the ambient temperature parameters, so as to perform low-temperature heating on the power battery pack.

[0015] The present invention also provides a new energy vehicle, including a memory and a processor, wherein the memory stores executable program code, and the processor calls and executes the executable program code to realize a method for low-temperature heating of the power battery.

[0016] The aforementioned low-temperature heating method, device, and new energy vehicle for power batteries acquire battery state parameters, ambient temperature parameters, and operating state parameters of heating-related modules of the power battery pack. Based on the temperature of each individual cell in the battery state parameters, the minimum temperature of each cell is determined. Then, based on the relationship between the minimum temperature of the individual cell and a preset temperature threshold, a target heating mode is determined. The target heating mode includes a heating mode with pulse self-heating parameters and heat pump heating parameters working in tandem. Based on the battery state parameters and the ambient temperature parameters, the pulse heating parameters and heat pump heating parameters of the target heating mode are dynamically adjusted to perform low-temperature heating of the power battery pack. This method can balance heating efficiency, energy consumption control, temperature uniformity, and heating safety, achieving rapid, uniform, energy-saving, and safe heating of the power battery pack in low-temperature environments. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic flowchart of a low-temperature heating method for a power battery provided in an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of a low-temperature heating device for a power battery provided in an embodiment of the present invention.

[0020] Figure 3 A schematic diagram of the structure of a computing device provided in an embodiment of this application. Detailed Implementation

[0021] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. Based on the description of the present invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present invention.

[0022] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0023] In the description of this invention, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0024] The terms “upper,” “lower,” “left,” “right,” “front,” “back,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use. They are only for the convenience of description and simplification, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0025] Moreover, the terms "first," "second," "third," etc., are merely used to distinguish elements with similar attributes, rather than to indicate or imply relative importance or a specific order.

[0026] Furthermore, the terms “including,” “comprising,” or any other variations thereof are intended to cover non-exclusive inclusion, which includes not only the elements listed but also other elements not expressly listed.

[0027] See Figure 1 This is a schematic flowchart of a low-temperature heating method for a power battery provided by an embodiment of the present invention. The method includes the following steps: S1: Obtain the battery status parameters, ambient temperature parameters, and operating status parameters of the heating-related modules of the power battery pack.

[0028] The battery status parameters may include at least one of the following: the temperature of each individual cell in the power battery pack, the total voltage of the power battery pack, the battery pack current, the state of charge (SOC), and the state of health (SOH). The ambient temperature parameter may be the temperature of the external environment where the vehicle or energy storage device is located, or the temperature of the area surrounding the power battery pack. The operating status parameters of the heating-related modules may include whether the heat pump system, pulse heating module, and waste heat recovery module are in normal working condition, and at least one of the following: the current power, current, operating mode, or fault status of each module.

[0029] In some embodiments, step S1 may include: obtaining battery status parameters of the power battery pack through the battery management system, obtaining ambient temperature parameters through the ambient temperature sensor, and obtaining operating status parameters of the heat pump system, pulse heating module, and waste heat recovery module.

[0030] In some embodiments, the battery management system can collect the above parameters in real time according to a preset sampling period. For example, the battery management system can collect ambient temperature, temperature of each individual cell, total voltage of the power battery pack, SOC and SOH, and detect whether there are faults in the heat pump system, pulse heating module and waste heat recovery module. When a fault is detected in any heating-related module, an alarm signal can be generated, and the heating function of the corresponding module can be stopped or restricted; when all heating-related modules are in normal working condition, the subsequent heating mode determination step is entered.

[0031] Step S1 provides the current low-temperature status, charge status, health status, and availability status of heating-related modules of the power battery pack, providing a data basis for determining the target heating mode and dynamically adjusting heating parameters.

[0032] S2: Determine the minimum temperature of each individual cell based on the temperature of each individual cell in the battery state parameters, and determine the target heating mode based on the relationship between the minimum temperature of the individual cell and the preset temperature threshold. The target heating mode includes a heating mode with pulse self-heating parameters and heat pump heating parameters working in tandem.

[0033] In this embodiment, the lowest temperature of a single battery cell refers to the lowest temperature among all the individual battery cells in the power battery pack. Since the charging and discharging capability of a power battery pack in low-temperature environments is usually limited by the lowest-temperature individual battery cell, this embodiment uses the lowest temperature of a single battery cell as an important basis for determining whether the power battery pack needs heating and for determining the heating mode.

[0034] In some embodiments, the step of determining the minimum temperature of a single cell based on the temperature of each individual cell in the battery state parameters, and determining the target heating mode based on the relationship between the minimum temperature of the single cell and a preset temperature threshold, further includes: Monitor the operating status of the heat pump system, pulse heating module, and waste heat recovery module; When the heat pump system, the pulse heating module, and the waste heat recovery module are all in normal working condition, the minimum temperature of each individual battery cell is determined based on the temperature of each individual battery cell, and the target heating mode is determined based on the relationship between the minimum temperature of the individual battery cell and the preset temperature threshold.

[0035] Specifically, the heat pump system refers to a heating system that uses a heat pump cycle to provide external heat to the power battery pack. It transfers heat to the power battery pack through components such as a compressor, heat exchanger, and refrigerant circulation loop. The pulse heating module refers to a module that applies a pulse current to the battery cells within the power battery pack, utilizing the internal resistance of the cells to generate heat and achieve internal self-heating. The waste heat recovery module refers to a module used to recover waste heat generated by heat source components such as the vehicle motor, electronic control module, braking system, and energy storage inverter, and transfer this waste heat to the power battery pack or other thermal management loops. The operating status refers to the status information regarding whether the above-mentioned heating-related modules can operate normally, which may include whether there is a fault, whether it is in a startable state, whether the current operating power is normal, and whether the temperature sensor or actuator is abnormal.

[0036] In this embodiment, before determining the target heating mode, the operating status of the heat pump system, pulse heating module, and waste heat recovery module is detected to determine whether each heating-related module is capable of participating in low-temperature heating. Only when the heat pump system, pulse heating module, and waste heat recovery module are all in normal working condition is the minimum temperature of each individual battery cell determined based on its temperature, and the target heating mode is determined based on the relationship between the minimum temperature of the individual battery cell and a preset temperature threshold. This avoids controlling the system according to the coordinated heating mode including a particular heating module even if a heating module fails or is unavailable, thereby reducing heating control failures or safety risks.

[0037] By employing the above-described scheme, this invention adds a step to detect the operating status of heating-related modules before determining the target heating mode. This ensures that the determination of the heating mode not only depends on the temperature state of the power battery pack but also further considers the actual availability of the heat pump system, pulse heating module, and waste heat recovery module. This improves the reliability and safety of target heating mode selection, avoiding the risk of abnormal heating due to heating module malfunctions, which could lead to inability to perform low-temperature heating, reduced heating efficiency, or other abnormal heating issues. Simultaneously, this scheme provides an effective preliminary judgment basis for the subsequent coordinated control of pulse self-heating, heat pump heating, and waste heat recovery heating, facilitating stable and safe heating of the power battery pack in low-temperature environments.

[0038] In some embodiments, determining the minimum temperature of a single battery cell based on the temperature of each individual cell in the battery state parameters, and determining a target heating mode based on the relationship between the minimum temperature of the single battery cell and a preset temperature threshold, includes: When the lowest temperature of the single cell is less than the first preset temperature threshold, the target heating mode is determined to be the first heating mode. In the first heating mode, the power battery pack is heated mainly by pulse self-heating and supplemented by heat pump heating. When the lowest temperature of the single cell is greater than or equal to the first preset temperature threshold and less than the second preset temperature threshold, the target heating mode is determined to be the second heating mode. In the second heating mode, the power battery pack is heated by pulse self-heating and heat pump heating in synergy. When the lowest temperature of the single cell is greater than or equal to the second preset temperature threshold and less than the third preset temperature threshold, the target heating mode is determined to be the third heating mode. In the third heating mode, the power battery pack is heated mainly by heat pump heating and supplemented by pulse self-heating. When the lowest temperature of the single cell is greater than or equal to the third preset temperature threshold, the target heating mode is determined to be the fourth heating mode. In the fourth heating mode, the power battery pack is controlled to stop low-temperature heating and enter the normal thermal management mode.

[0039] Specifically, when the lowest temperature of the individual battery cell is lower than a first preset temperature threshold, it indicates that the power battery pack is in a low-temperature state, and the target heating mode can be determined as the first heating mode. In the first heating mode, the power battery pack can be heated primarily by pulse self-heating and secondarily by heat pump heating to improve the temperature rise rate of the power battery pack at extremely low temperatures.

[0040] When the lowest temperature of the individual battery cell is greater than or equal to a first preset temperature threshold and less than a second preset temperature threshold, the target heating mode can be determined as the second heating mode. In the second heating mode, the power battery pack can be heated by a combination of pulse self-heating and heat pump heating, so that the power battery pack can reduce the energy consumption or temperature difference problems caused by a single heating method while ensuring the heating efficiency.

[0041] When the lowest temperature of the individual battery cell is greater than or equal to the second preset temperature threshold and less than the third preset temperature threshold, the target heating mode can be determined as the third heating mode. In the third heating mode, the power battery pack can be heated primarily by heat pump heating and secondarily by pulse self-heating. This makes the heating process more stable as the power battery pack temperature gradually approaches the target temperature, and reduces the impact of excessive pulse heating on battery capacity and battery status.

[0042] When the lowest temperature of the individual battery cell is greater than or equal to the third preset temperature threshold, it indicates that the power battery pack has reached or is close to the suitable operating temperature, and the target heating mode can be determined as the fourth heating mode. In the fourth heating mode, the power battery pack can be controlled to stop low-temperature heating and enter the normal thermal management mode.

[0043] In one specific embodiment, the first preset temperature threshold, the second preset temperature threshold, and the third preset temperature threshold can be set according to the power battery type, application scenario, and low-temperature start-up requirements. For example, the first preset temperature threshold can be set to -30℃ or -20℃, the second preset temperature threshold can be set to -10℃, and the third preset temperature threshold can be set to 15℃. The above thresholds are merely examples and do not constitute a limitation on the scope of protection of this invention.

[0044] Through the above-described scheme of determining the target heating mode in a tiered manner, it can be seen that this invention does not simply control the heating start and stop based on a single temperature threshold, but rather differentiates the participation of pulse self-heating and heat pump heating according to the different temperature ranges where the lowest temperature of a single battery cell is located. Specifically, when the power battery pack temperature is low, pulse self-heating is the primary method, which can utilize the heat generated by the internal resistance of the battery cell to achieve rapid temperature rise; when the power battery pack temperature is in the intermediate low temperature range, pulse self-heating and heat pump heating work together, which can reduce the problems of excessive energy consumption or uneven temperature caused by a single heating method while ensuring heating efficiency; when the power battery pack temperature gradually approaches the suitable operating temperature, heat pump heating is the primary method and pulse self-heating is the secondary method, which can make the heating process more stable and reduce the adverse effects on battery charge and battery health; when the power battery pack reaches or approaches the target temperature, low-temperature heating is stopped in time and the normal thermal management mode is entered, which can avoid energy waste and overheating risks caused by continuous heating. Therefore, the technical solution of the present invention can adaptively select the heating mode according to the actual low temperature of the power battery pack, taking into account rapid temperature rise at low temperature, energy consumption control, temperature uniformity and heating safety, thereby improving the thermal management effect of the power battery pack in low temperature environment.

[0045] S3: Based on the battery state parameters and the ambient temperature parameters, dynamically adjust the pulse heating parameters and the heat pump heating parameters of the target heating mode to perform low-temperature heating on the power battery pack.

[0046] In this embodiment, the pulse heating parameters may include at least one of the following: pulse frequency, current amplitude, pulse duration, pulse duty cycle, or alternating charge-discharge control parameters between different battery cell groups. The heat pump heating parameters may include at least one of the following: target heating power, heating output, operating time, or heat exchange intensity of the heat pump system.

[0047] In some embodiments, dynamically adjusting the pulse heating parameters and the heat pump heating parameters of the target heating mode based on the battery state parameters and the ambient temperature parameters includes: The pulse frequency and current amplitude of the pulse heating module are determined based on the lowest temperature of the individual battery cell, the state of charge (SOC), and the battery health (SOH). When the minimum temperature of the single cell decreases and the state of charge (SOC) meets the preset charge condition, the pulse frequency and / or the current amplitude are increased. When the lowest temperature of the single cell approaches the preset heating stop condition, or the state of charge (SOC) is lower than the preset limit threshold, the pulse frequency and / or the current amplitude are reduced. The pulse heating module controls at least two sets of cells in the power battery pack to charge and discharge alternately, enabling the power battery pack to achieve self-heating based on the heat generated by the internal resistance of the cells.

[0048] Specifically, the lowest temperature of a single cell refers to the lowest temperature of each individual cell in the battery pack, reflecting the condition of the cell with the most severe low-temperature state. Since the charge / discharge capacity and low-temperature safety of the battery pack are typically limited by the lowest-temperature cell, using the lowest cell temperature as a key criterion for determining the pulse heating intensity allows for heating control that more closely matches the actual low-temperature state of the battery pack. The State of Charge (SOC) refers to the ratio of the battery pack's current remaining charge to its rated capacity, reflecting the current charge level available for heating and vehicle operation. The Battery Health (SOH) refers to the degree of performance degradation of the battery pack relative to its initial performance, reflecting its aging state and withstandable heating intensity. The pulse frequency refers to the frequency of periodic changes in current during pulse heating; the current amplitude refers to the magnitude of the current applied to the cell assembly during pulse heating. Higher pulse frequencies and current amplitudes generally indicate greater pulse self-heating intensity and more heat generated by the cell based on its internal resistance; conversely, lower frequencies and current amplitudes indicate reduced heating intensity.

[0049] In this embodiment, when the minimum temperature of a single cell is low and the state of charge (SOC) meets the preset charge condition, it indicates that the power battery pack still has sufficient charge for pulse self-heating. At this time, the pulse frequency and / or current amplitude can be appropriately increased to enhance the heat generation effect of the cell's internal resistance and increase the temperature rise rate. When the minimum temperature of a single cell approaches the preset stop heating condition, it indicates that the power battery pack is close to the target heating temperature. At this time, reducing the pulse frequency and / or current amplitude can avoid excessive heating caused by continued high-intensity heating. When the SOC is lower than the preset limit threshold, it indicates that the remaining charge of the power battery pack is insufficient. At this time, reducing the pulse frequency and / or current amplitude can reduce the power consumption of pulse self-heating and ensure the basic operating requirements of the vehicle. The alternating charging and discharging of at least two groups of cells refers to dividing the cells in the power battery pack into at least two groups of cells and controlling the alternating charging and discharging of different groups of cells, so that the cells generate heat using their internal resistance during current flow, thereby achieving internal self-heating of the power battery pack.

[0050] As can be seen from the above scheme, this invention does not use a fixed pulse heating intensity to heat the power battery pack. Instead, it dynamically adjusts the pulse frequency and current amplitude by comprehensively considering the minimum temperature of individual cells, the state of charge (SOC), and the state of health (SOH). Therefore, when the temperature is low and the battery capacity allows, the pulse self-heating intensity can be increased, thereby improving the low-temperature heating rate of the power battery pack. When the battery is close to the target temperature, the charge is insufficient, or the battery health condition is unsuitable for high-intensity heating, the pulse self-heating intensity can be reduced, thereby reducing power consumption, suppressing overheating, and minimizing the impact on battery life and safety. Therefore, this scheme can ensure low-temperature heating efficiency while simultaneously considering energy consumption control, battery protection, and heating safety.

[0051] In some embodiments, determining the pulse frequency and current amplitude of the pulse heating module based on the lowest temperature of the individual battery cell, the state of charge (SOC), and the battery health (SOH) further includes: The temperature difference between the highest and lowest temperatures of a single battery cell is determined based on the temperature of each individual battery cell. When the temperature difference of the battery cells is greater than a preset temperature difference threshold, the pulse current amplitude corresponding to the battery cell group with lower temperature is increased, and / or the pulse current amplitude corresponding to the battery cell group with higher temperature is decreased. Differential heating control is applied to different cell groups based on the adjusted pulse current amplitude, so that the temperature difference between individual cells in the power battery pack is reduced to the target temperature difference range.

[0052] Specifically, the highest temperature of a single battery cell refers to the highest temperature of each single battery cell in the power battery pack; the lowest temperature of a single battery cell refers to the lowest temperature of each single battery cell in the power battery pack; the cell temperature difference refers to the difference between the highest and lowest temperatures of a single battery cell, which reflects the temperature consistency among different single battery cells within the power battery pack. The preset temperature difference threshold is a standard for judging whether the temperature difference within the power battery pack is too large, and can be set according to battery type, battery pack structure, thermal management requirements, and safety control needs. The target temperature difference range refers to the temperature equilibrium range that the power battery pack is expected to achieve or maintain during the heating process.

[0053] In this embodiment, when the temperature difference between the cells exceeds a preset temperature difference threshold, it indicates a significant temperature imbalance between different individual cells within the power battery pack. In this case, for cell groups with lower temperatures, the corresponding pulse current amplitude can be increased, causing them to generate more heat based on their internal resistance during alternating charge and discharge, thereby accelerating the temperature rise of the low-temperature cell groups. For cell groups with higher temperatures, the corresponding pulse current amplitude can be decreased, relatively reducing heat generation and preventing the high-temperature cell groups from continuing to heat up rapidly. The differentiated heating control refers to not using the same pulse heating parameters for all cell groups within the power battery pack, but rather adjusting the pulse current amplitude according to the actual temperature state of each cell group to achieve zoned, grouped, or graded heating control for different cell groups.

[0054] The above scheme allows for further consideration of temperature consistency within the power battery pack during pulse self-heating. When significant temperature differences exist between cells within the power battery pack, increasing the pulse current amplitude of the low-temperature cell group and / or decreasing the pulse current amplitude of the high-temperature cell group can accelerate the heating of low-temperature cells and limit heat generation in high-temperature cells, thereby gradually reducing the temperature difference between individual cells. This avoids the problems of insufficient heating in some cells and localized overheating in others when using uniform pulse heating parameters, improving temperature uniformity and safety during the low-temperature heating process of the power battery pack. It also helps reduce performance differences between cells and mitigates the risks of decreased capacity utilization, limited charge / discharge, or battery life degradation caused by excessive temperature differences.

[0055] In some embodiments, the dynamic adjustment of the pulse heating parameters and the heat pump heating parameters of the target heating mode based on the battery state parameters and the ambient temperature parameters further includes: The target heating power of the heat pump system is determined based on the ambient temperature parameters and the difference between the lowest temperature of the individual battery cell and the preset stop temperature threshold. When the ambient temperature decreases and / or the difference between the lowest temperature of the individual battery cell and the preset stop temperature threshold increases, the target heating power of the heat pump system is increased. When the lowest temperature of the individual battery cell approaches the preset stop temperature threshold, the target heating power of the heat pump system is reduced to suppress overheating.

[0056] Specifically, the ambient temperature parameter refers to the temperature of the external environment where the vehicle is located, or the temperature of the area surrounding the power battery pack, which reflects the external cooling effect on the power battery pack in low-temperature environments. Generally, the lower the ambient temperature, the faster the power battery pack loses heat to the outside, and the greater the difficulty in heating up under the same heating conditions. The preset stop temperature threshold refers to the temperature judgment standard corresponding to the completion or cessation of low-temperature heating of the power battery pack, which can be set according to the power battery type, low-temperature start-up requirements, charging and discharging performance requirements, and safety control requirements. The difference between the lowest temperature of a single battery cell and the preset stop temperature threshold reflects the gap between the current temperature of the power battery pack and the target stop heating temperature; the larger the difference, the farther the power battery pack is from the target heating temperature, and the stronger the heating demand. The target heating power of the heat pump system refers to the heating power that the heat pump system needs to output during the current heating stage, which can be achieved by adjusting the compressor speed, refrigerant circulation volume, heat exchanger operating status, or thermal management loop flow rate.

[0057] In this embodiment, when the ambient temperature decreases, it indicates that the power battery pack is more affected by the external low temperature, and the rate of heat loss increases. At this time, the target heating power of the heat pump system can be increased to compensate for the heat loss caused by the low temperature environment. When the difference between the lowest temperature of a single cell and the preset stop temperature threshold increases, it indicates that the current temperature of the power battery pack is far from the target temperature, requiring stronger external heating capabilities. At this time, the target heating power of the heat pump system can also be increased to improve the heating rate of the power battery pack. Conversely, when the lowest temperature of a single cell gradually approaches the preset stop temperature threshold, it indicates that the power battery pack is approaching the target heating state. At this time, reducing the target heating power of the heat pump system can change the heating process from rapid heating to stable convergence, avoiding temperature overshoot or energy waste caused by continuing to heat at a higher power.

[0058] The above-described scheme dynamically adjusts the target heating power of the heat pump system based on the difference between the ambient temperature and the current temperature of the power battery pack and the target temperature, rather than operating the heat pump system at a fixed power level. Therefore, when the ambient temperature is low or the power battery pack is far from the target temperature, the heat pump heating power can be increased to enhance low-temperature heating capability and shorten the power battery pack's heating time. When the power battery pack approaches the preset stop temperature threshold, the heat pump heating power can be reduced to suppress overheating and temperature overshoot, reducing unnecessary energy consumption. Thus, this scheme improves the precision of heat pump heating control while ensuring heating efficiency, balancing low-temperature heating effect, energy consumption control, and heating safety.

[0059] In one specific embodiment, the pulse frequency of the pulse heating module can be set within the range of 100Hz to 500Hz, and the current amplitude can be set within the range of 0.1C to 0.5C; the target heating power of the heat pump system can be set within the range of 1kW to 5kW. When the minimum temperature of a single battery cell is lower and the state of charge (SOC) is higher, the pulse frequency and current amplitude can be appropriately increased; when the ambient temperature is lower, or the difference between the minimum temperature of a single battery cell and the preset stop temperature threshold is larger, the target heating power of the heat pump system can be appropriately increased. The above parameter ranges are merely examples and can be adjusted according to the type, capacity, application scenario, and safety requirements of the power battery.

[0060] In some embodiments, auxiliary heating can be provided in conjunction with a waste heat recovery module while performing pulse self-heating and heat pump heating. Specifically, the waste heat temperature of at least one heat source component among the vehicle motor, electronic control module, braking system, or energy storage inverter can be obtained. When the waste heat temperature is greater than a preset waste heat recovery temperature threshold, the waste heat recovery module is activated, and the waste heat generated by the heat source component is transferred to the power battery pack through a heat exchanger and circulation pipeline. Further, the opening of the three-way valve can be adjusted based on the waste heat temperature and the heating requirements of the power battery pack to distribute the waste heat to the power battery pack and / or the cabin heating circuit; when the waste heat temperature is not greater than the preset waste heat recovery temperature threshold, the waste heat recovery module can be shut down, or the waste heat supply ratio of the waste heat recovery module can be reduced.

[0061] Specifically, the vehicle motor, electronic control module, braking system, or energy storage inverter refer to components that may generate heat during the operation of a new energy vehicle. These components generate heat during vehicle driving, energy conversion, braking energy recovery, or electrical energy conversion. If this heat is not utilized, it is typically dissipated outside the vehicle through the cooling system. The waste heat temperature refers to the temperature corresponding to the recoverable heat generated by the aforementioned heat source components, reflecting whether the heat source component currently possesses heat suitable for heating the power battery pack. The preset waste heat recovery temperature threshold is a temperature standard for determining whether waste heat has recycling value, which can be set according to the heating requirements of the power battery pack, heat exchange efficiency, and the vehicle's thermal management system structure. The heat exchanger is a component used for heat transfer between the heat source components and the power battery pack heating circuit; the circulation pipeline is a fluid channel used to transport coolant, heat transfer medium, or other heat exchange media. The three-way valve is a valve body that can change the fluid flow direction or flow distribution ratio in the thermal management circuit. By adjusting the opening of the three-way valve, more waste heat can be directed to the power battery pack or distributed to the cabin heating circuit.

[0062] In this embodiment, when the waste heat temperature exceeds the preset waste heat recovery temperature threshold, it indicates that the waste heat generated by the vehicle's heat source components has a certain value for recycling. At this time, activating the waste heat recovery module allows this portion of waste heat to be transferred to the power battery pack via a heat exchanger and circulation pipeline, serving as an auxiliary heat source in addition to pulse self-heating and heat pump heating. When the waste heat temperature is high and the power battery pack heating demand is strong, the opening of the three-way valve can be adjusted to distribute more waste heat to the power battery pack heating circuit. Conversely, when the power battery pack heating demand decreases, or the cabin heating demand is high, the opening of the three-way valve can also be adjusted to distribute some waste heat to the cabin heating circuit. When the waste heat temperature is not greater than the preset waste heat recovery temperature threshold, it indicates that the current waste heat temperature is insufficient to effectively support power battery pack heating. At this time, shutting down the waste heat recovery module or reducing the waste heat supply ratio can prevent ineffective circulation and additional energy consumption.

[0063] The above solution allows for the introduction of waste heat generated during vehicle operation as an auxiliary heating source, building upon pulse self-heating and heat pump heating. This reduces reliance on heat pump systems or pulse self-heating alone during low-temperature battery pack heating, improving overall vehicle heat utilization and reducing additional energy consumption. Furthermore, by adjusting the opening of the three-way valve based on waste heat temperature and battery pack heating requirements, flexible distribution of waste heat between the battery pack heating circuit and the cabin heating circuit can be achieved, making heat supply more aligned with actual needs. This solution improves overall vehicle energy efficiency while ensuring effective low-temperature battery pack heating, and also contributes to improved vehicle range and overall thermal management system efficiency in low-temperature environments.

[0064] In some embodiments, during the low-temperature heating process, at least one of the following parameters can be continuously monitored: individual cell temperature, battery pack voltage, battery pack current, SOC, SOH, pulse heating module operating parameters, heat pump system operating parameters, and waste heat recovery module operating parameters.

[0065] When the minimum temperature of a single battery cell reaches the preset stop temperature threshold, at least one of the pulse heating module, heat pump system, and waste heat recovery module can be stopped.

[0066] When at least one of the following abnormal conditions is detected: abnormal increase in temperature of a single cell, abnormal fluctuation in battery pack voltage, abnormal fluctuation in battery pack current, or failure of heating-related modules, the low-temperature heating can be stopped, an alarm signal can be generated, and fault information can be recorded.

[0067] When the SOC is lower than the preset low power threshold, the pulse heating module can be stopped or limited, while heat pump heating and / or waste heat recovery heating can be retained.

[0068] When the temperature of each individual battery cell reaches the preset target temperature range, the battery pack can enter the heat preservation mode to maintain the temperature of the power battery pack within the preset heat preservation temperature range.

[0069] In this embodiment, continuous monitoring of the above parameters during the low-temperature heating process allows for real-time assessment of the battery pack's temperature changes, charge status, health status, and the operational status of each heating-related module. When the lowest temperature of a single cell reaches a preset stop temperature threshold, it indicates that the battery pack has reached the low-temperature heating target or has achieved satisfactory operating temperature conditions. At this point, stopping at least one of the pulse heating module, heat pump system, and waste heat recovery module can prevent energy waste or temperature overshoot caused by continued heating. When abnormal increases in single cell temperature, abnormal fluctuations in battery pack voltage, abnormal fluctuations in battery pack current, or malfunctions in heating-related modules are detected, it indicates that the low-temperature heating process may pose risks such as localized overheating, electrical abnormalities, or heating module failure. In this case, stopping the low-temperature heating, generating an alarm signal, and recording fault information can promptly interrupt the abnormal heating process and provide a basis for subsequent fault diagnosis, repair, or safety tracing.

[0070] Furthermore, when the State of Charge (SOC) is below the preset low-charge threshold, it indicates that the remaining charge of the power battery pack is low. Continuing to perform high-intensity pulse self-heating may further increase power consumption and affect vehicle range or low-temperature start-up reliability. Therefore, the pulse heating module can be stopped or limited, while heat pump heating and / or waste heat recovery heating can be retained to maintain necessary heating capacity while reducing the battery's own power consumption. When the temperature of each individual cell reaches the preset target temperature range, the system enters the heat preservation mode. This means that high-intensity temperature rise control is no longer continuously performed. Instead, the power battery pack temperature is maintained within the preset heat preservation temperature range through lower power, intermittent operation, or on-demand activation, thereby reducing the possibility of the power battery pack rapidly cooling down again in low-temperature environments.

[0071] Through the above-described solution, this invention introduces safety management measures such as continuous monitoring, heating cessation, abnormal alarms, low battery protection, and heat preservation control during the low-temperature heating process. This allows for timely stopping or reducing the heating intensity when the power battery pack reaches the target temperature, avoiding overheating and energy waste; timely interruption of low-temperature heating and recording of fault information in case of abnormalities in temperature, voltage, current, or module malfunctions, improving the safety and traceability of the heating process; limiting pulse self-heating at low SOC levels helps reduce power consumption and ensures basic vehicle operation needs; and entering heat preservation mode after reaching the target temperature reduces the number of repeated heating cycles, improving thermal management stability in low-temperature environments. Therefore, this solution further enhances the safety, reliability, energy efficiency, and operational stability of the power battery pack's low-temperature heating process while ensuring effective low-temperature heating.

[0072] Through step S3, the pulse self-heating parameters and heat pump heating parameters can be dynamically adjusted according to the real-time temperature, charge status, health status of the power battery pack and the external ambient temperature. Combined with waste heat recovery and safety monitoring mechanisms, the power battery pack can be heated quickly, uniformly, energy-savingly and safely in low-temperature environments.

[0073] The aforementioned low-temperature heating method for power batteries acquires battery state parameters, ambient temperature parameters, and operating state parameters of heating-related modules of the power battery pack. Based on the temperature of each individual cell in the battery state parameters, it determines the minimum temperature of each cell and, based on the relationship between the minimum temperature of the individual cell and a preset temperature threshold, determines a target heating mode. The target heating mode includes a heating mode with pulse self-heating parameters and heat pump heating parameters working in tandem. Based on the battery state parameters and the ambient temperature parameters, it dynamically adjusts the pulse heating parameters and the heat pump heating parameters of the target heating mode to perform low-temperature heating of the power battery pack. This method can balance heating efficiency, energy consumption control, temperature uniformity, and heating safety, achieving rapid, uniform, energy-saving, and safe heating of the power battery pack in low-temperature environments.

[0074] Based on the same inventive concept as the foregoing embodiments, this application provides a low-temperature heating device for power batteries, such as... Figure 2 As shown, the device includes: The parameter acquisition unit 201 is used to acquire the battery status parameters, ambient temperature parameters, and working status parameters of the heating-related modules of the power battery pack. The heating mode determination unit 202 is used to determine the minimum temperature of each individual cell based on the temperature of each individual cell in the battery state parameters, and to determine the target heating mode based on the relationship between the minimum temperature of the individual cell and a preset temperature threshold. The target heating mode includes a heating mode with pulse self-heating parameters and heat pump heating parameters working together. The parameter adjustment unit 203 is used to dynamically adjust the pulse heating parameters and the heat pump heating parameters of the target heating mode based on the battery state parameters and the ambient temperature parameters, so as to perform low-temperature heating on the power battery pack.

[0075] When the device is in operation, it implements the aforementioned method for low-temperature heating of the power battery.

[0076] Based on the same inventive concept as the foregoing embodiments, this application provides a new energy vehicle, the vehicle comprising: Memory, used to store executable program code; The processor is used to call and execute the executable program code to enable the vehicle to perform the aforementioned low-temperature heating method for the power battery.

[0077] Based on the same inventive concept as the foregoing embodiments, this application provides a computer device, such as... Figure 3 As shown, the computer device includes: a processor 410 and a memory 411 storing a computer program; wherein, Figure 3 The processor 410 shown in the diagram does not indicate that there is only one processor 410, but only indicates the positional relationship of the processor 410 relative to other devices. In practical applications, there can be one or more processors 410; similarly, Figure 3 The memory 411 shown in the diagram has the same meaning, that is, it is only used to indicate the positional relationship of memory 411 relative to other devices. In practical applications, there can be one or more memories 411. When the processor 410 runs the computer program, the above-described method for low-temperature heating of the power battery is implemented.

[0078] The computing device may also include at least one network interface 412. The various components of the computing device are coupled together via a bus system 413. It is understood that the bus system 413 is used to implement communication between these components. In addition to a data bus, the bus system 413 also includes a power bus, a control bus, and a status signal bus. However, for clarity, in... Figure 3 The general designated all buses as Bus System 413.

[0079] The memory 411 can be volatile or non-volatile, or both. Non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), ferromagnetic random access memory (FRAM), flash memory, magnetic surface memory, optical disc, or compact disc read-only memory (CD-ROM); magnetic surface memory can be disk storage or magnetic tape storage. Volatile memory can be random access memory (RAM), used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Synchronous Static Random Access Memory (SSRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic Random Access Memory (SDRAM), Double Data Rate Synchronous Dynamic Random Access Memory (DDRSDRAM), Enhanced Synchronous Dynamic Random Access Memory (ESDRAM), SyncLink Dynamic Random Access Memory (SLDRAM), and Direct Rambus Random Access Memory (DRRAM).The memory 411 described in the embodiments of this application is intended to include, but is not limited to, these and any other suitable types of memory.

[0080] The memory 411 in this embodiment is used to store various types of data to support the operation of the computing device. Examples of this data include: any computer programs used to operate on the computing device, such as operating systems and applications; contact data; phonebook data; messages; pictures; videos, etc. The operating system includes various system programs, such as the framework layer, core library layer, driver layer, etc., used to implement various basic services and handle hardware-based tasks. Applications can include various applications, such as media players, browsers, etc., used to implement various application services. Here, the program implementing the method of this embodiment can be included in the application.

[0081] Based on the same inventive concept as the foregoing embodiments, this embodiment also provides a computer-readable storage medium storing a computer program. The computer-readable storage medium can be a magnetic random access memory (FRAM), a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a flash memory, a magnetic surface memory, an optical disc, or a compact disc read-only memory (CD-ROM), etc.; it can also be various devices including one or any combination of the above-mentioned memories, such as mobile phones, computers, tablet devices, personal digital assistants, etc. When the computer program stored in the computer-readable storage medium is executed by a processor, it implements the above-described method for low-temperature heating of a power battery. For the specific steps implemented when the computer program is executed by the processor, please refer to [link to relevant documentation]. Figure 1 The description of the illustrated embodiments will not be repeated here.

[0082] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0083] In this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, which includes not only the elements listed but also other elements not expressly listed.

[0084] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for low-temperature heating of a power battery, characterized in that, The method includes: Obtain the battery status parameters, ambient temperature parameters, and operating status parameters of the heating-related modules of the power battery pack; The minimum temperature of each individual cell is determined based on the temperature of each individual cell in the battery state parameters. Based on the relationship between the minimum temperature of the individual cell and a preset temperature threshold, a target heating mode is determined. The target heating mode includes a heating mode with pulse self-heating parameters and heat pump heating parameters working in tandem. Based on the battery state parameters and the ambient temperature parameters, the pulse heating parameters and the heat pump heating parameters of the target heating mode are dynamically adjusted to heat the power battery pack at low temperatures.

2. The method according to claim 1, characterized in that, The step of determining the minimum temperature of each individual cell based on the temperature of each individual cell in the battery state parameters, and determining the target heating mode based on the relationship between the minimum temperature of the individual cell and a preset temperature threshold, further includes: Monitor the operating status of the heat pump system, pulse heating module, and waste heat recovery module; When the heat pump system, the pulse heating module, and the waste heat recovery module are all in normal working condition, the minimum temperature of each individual battery cell is determined based on the temperature of each individual battery cell, and the target heating mode is determined based on the relationship between the minimum temperature of the individual battery cell and the preset temperature threshold.

3. The method according to claim 1, characterized in that, The step of determining the minimum temperature of each individual cell based on the temperature of each individual cell in the battery state parameters, and determining the target heating mode based on the relationship between the minimum temperature of the individual cell and a preset temperature threshold, includes: When the lowest temperature of the single cell is less than the first preset temperature threshold, the target heating mode is determined to be the first heating mode. In the first heating mode, the power battery pack is heated mainly by pulse self-heating and supplemented by heat pump heating. When the lowest temperature of the single cell is greater than or equal to the first preset temperature threshold and less than the second preset temperature threshold, the target heating mode is determined to be the second heating mode. In the second heating mode, the power battery pack is heated by pulse self-heating and heat pump heating in synergy. When the lowest temperature of the single cell is greater than or equal to the second preset temperature threshold and less than the third preset temperature threshold, the target heating mode is determined to be the third heating mode. In the third heating mode, the power battery pack is heated mainly by heat pump heating and supplemented by pulse self-heating. When the lowest temperature of the single cell is greater than or equal to the third preset temperature threshold, the target heating mode is determined to be the fourth heating mode. In the fourth heating mode, the power battery pack is controlled to stop low-temperature heating and enter the normal thermal management mode.

4. The method according to claim 1, characterized in that, The battery status parameters include at least one of the following: the temperature of each individual cell in the power battery pack, the total voltage of the power battery pack, the state of charge (SOC), and the battery health (SOH). The step of dynamically adjusting the pulse heating parameters and the heat pump heating parameters of the target heating mode based on the battery state parameters and the ambient temperature parameters includes: The pulse frequency and current amplitude of the pulse heating module are determined based on the lowest temperature of the individual battery cell, the state of charge (SOC), and the battery health (SOH). When the minimum temperature of the single cell decreases and the state of charge (SOC) meets the preset charge condition, the pulse frequency and / or the current amplitude are increased. When the lowest temperature of the single cell approaches the preset heating stop condition, or the state of charge (SOC) is lower than the preset limit threshold, the pulse frequency and / or the current amplitude are reduced. The pulse heating module controls at least two sets of cells in the power battery pack to charge and discharge alternately, enabling the power battery pack to achieve self-heating based on the heat generated by the internal resistance of the cells.

5. The method according to claim 4, characterized in that, The step of determining the pulse frequency and current amplitude of the pulse heating module based on the lowest temperature of the individual battery cell, the state of charge (SOC), and the battery health (SOH) further includes: The temperature difference between the highest and lowest temperatures of a single battery cell is determined based on the temperature of each individual battery cell. When the temperature difference of the battery cells is greater than a preset temperature difference threshold, the pulse current amplitude corresponding to the battery cell group with lower temperature is increased, and / or the pulse current amplitude corresponding to the battery cell group with higher temperature is decreased. Differential heating control is applied to different cell groups based on the adjusted pulse current amplitude, so that the temperature difference between individual cells in the power battery pack is reduced to the target temperature difference range.

6. The method according to claim 1, characterized in that, The step of dynamically adjusting the pulse heating parameters and the heat pump heating parameters of the target heating mode based on the battery state parameters and the ambient temperature parameters further includes: The target heating power of the heat pump system is determined based on the ambient temperature parameters and the difference between the lowest temperature of the individual battery cell and the preset stop temperature threshold. When the ambient temperature decreases and / or the difference between the lowest temperature of the individual battery cell and the preset stop temperature threshold increases, the target heating power of the heat pump system is increased. When the lowest temperature of the individual battery cell approaches the preset stop temperature threshold, the target heating power of the heat pump system is reduced to suppress overheating.

7. The method according to claim 1, characterized in that, The method further includes: Obtain the waste heat temperature of at least one heat source component in the vehicle motor, electronic control module, braking system, or energy storage inverter; When the waste heat temperature is greater than the preset waste heat recovery temperature threshold, the waste heat recovery module is activated, and the waste heat generated by the heat source component is transferred to the power battery pack through the heat exchanger and circulation pipeline. Based on the waste heat temperature and the heating requirements of the power battery pack, adjust the opening of the three-way valve to distribute the waste heat to the power battery pack and / or the cabin heating circuit. When the waste heat temperature is not greater than the preset waste heat recovery temperature threshold, the waste heat recovery module is turned off, or the waste heat supply ratio of the waste heat recovery module is reduced.

8. The method according to claim 1, characterized in that, The battery status parameters include at least one of the following: temperature of each individual cell in the power battery pack, total voltage of the power battery pack, state of charge (SOC), and state of health (SOH). The method further includes: During the heating process, at least one of the following is monitored: temperature of each individual cell, battery pack voltage, battery pack current, state of charge (SOC), battery health (SOH), pulse heating module operating parameters, heat pump system operating parameters, and waste heat recovery module operating parameters. When the minimum temperature of the single cell reaches the preset stop temperature threshold, at least one of the pulse heating module, the heat pump system, and the waste heat recovery module is stopped. When at least one of the following abnormal conditions is detected: abnormal increase in temperature of a single cell, abnormal fluctuation in battery pack voltage, abnormal fluctuation in battery pack current, or failure of heating-related modules, low-temperature heating is stopped, an alarm signal is generated, and fault information is recorded. When the state of charge (SOC) is lower than a preset low charge threshold, the pulse heating module is stopped or limited, while heat pump heating and / or waste heat recovery heating are retained. When the temperature of each individual battery cell reaches the preset target temperature range, the battery pack enters the heat preservation mode to maintain the temperature of the power battery pack within the preset heat preservation temperature range.

9. A low-temperature heating device for a power battery, characterized in that, The device includes: The parameter acquisition unit is used to acquire the battery status parameters, ambient temperature parameters, and working status parameters of the heating-related modules of the power battery pack. A heating mode determination unit is used to determine the minimum temperature of a single cell based on the temperature of each cell in the battery state parameters, and to determine a target heating mode based on the relationship between the minimum temperature of the single cell and a preset temperature threshold. The target heating mode includes a heating mode with pulse self-heating parameters and heat pump heating parameters working together. The parameter adjustment unit is used to dynamically adjust the pulse heating parameters and the heat pump heating parameters of the target heating mode based on the battery state parameters and the ambient temperature parameters, so as to perform low-temperature heating on the power battery pack.

10. A new energy vehicle, characterized in that, The vehicle includes: Memory, used to store executable program code; A processor is configured to call and execute the executable program code to cause the vehicle to perform the low-temperature heating method for the power battery as described in any one of claims 1 to 8.

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