A new energy vehicle battery thermal management system

Abstract

The application relates to the technical field of new energy vehicles, in particular to a new energy vehicle battery thermal management system, which comprises a battery pack, an acquisition module, a sensing module, a heating module, a circulation module, an analysis module and a control module. The application integrates three heating modes of PTC heating, pulse heating and heat pump waste heat utilization, and realizes automatic determination and switching of the three heating modes based on a vehicle dynamic load index and a temperature difference in a cab, overcomes the defects of only using a single heating mode in the prior art, realizes adaptive identification and dynamic adjustment of the system, improves adaptive temperature control capability and energy efficiency level of the thermal management system in a wide temperature range, thereby improving working temperature conditions of the battery in a low temperature environment, and guaranteeing battery life and vehicle endurance.

Description

Technical Field

[0001] This invention relates to the field of new energy vehicle technology, and in particular to a new energy vehicle battery thermal management system. Background Technology

[0002] With the rapid increase in the penetration rate of new energy vehicles, consumers are placing increasingly higher demands on vehicle range, winter energy efficiency, fast charging safety, and battery life. As a core technology that simultaneously affects these four indicators, the performance of the battery thermal management system directly determines the vehicle's usability and reliability in extreme climates. However, existing thermal management systems still have significant shortcomings in terms of wide-range temperature adaptability, energy efficiency optimization, and intelligent control: high energy consumption for heating at low temperatures, insufficient heat dissipation capacity when combined with fast charging at high temperatures, and traditional threshold-triggered control cannot adaptively adjust based on vehicle driving status, cabin thermal demand, and real-time battery status. Furthermore, there is a lack of efficient collaborative switching mechanisms between different heating and cooling modes. These shortcomings make it difficult for existing systems to simultaneously meet the comprehensive needs of safety, energy efficiency, and user experience. Therefore, there is an urgent need for a new energy vehicle battery thermal management system that can adaptively identify thermal load states and dynamically adjust multiple heating modes to maximize vehicle energy efficiency while ensuring battery safety, thus meeting consumers' expectations for the next generation of electric mobility.

[0003] Chinese Patent Publication No. CN117341414A discloses a battery heating control method and device, controller, electric vehicle, and medium. The electric vehicle includes a PTC heater and a heating proportional valve. The battery heating control method of the electric vehicle first generates a heating request for the power battery based on the temperature and SOC of the power battery. Then, in response to the heating request, the PTC heater is started. The opening of the heating proportional valve is controlled to enable the PTC heater to heat the power battery. During the heating process, the target heating temperature of the PTC heater is determined in real time based on the inlet temperature of the power battery and the ambient temperature. The heating power of the PTC heater is then adjusted according to the real-time determined target heating temperature.

[0004] Therefore, although the aforementioned solution can adjust the target heating temperature and heating power in real time based on the battery inlet temperature and ambient temperature through the cooperation of the PTC heater and the heating proportional valve, it has the following problems: This solution only uses PTC heating to heat the battery pack, lacking coordinated control and dynamic adjustment between different heating methods. This results in the inability to adaptively switch heating based on the cabin temperature and vehicle driving parameters. Furthermore, it lacks adaptive identification based on thermal load conditions, which means that the optimal heating strategy cannot be matched under wide temperature range conditions, reducing heating efficiency and system energy efficiency in low-temperature environments. Summary of the Invention

[0005] Therefore, the present invention provides a new energy vehicle battery thermal management system to overcome the problem that the existing technology only uses a single heating method and cannot adaptively identify and dynamically adjust the heating mode according to the heat load state.

[0006] To achieve the above objectives, the present invention provides a new energy vehicle battery thermal management system, comprising: A battery pack comprising a plurality of interconnected cells; wherein the cells can receive high-frequency pulse current and generate heat using their own internal resistance to achieve pulse heating; A data acquisition module is used to monitor and acquire the operating parameters of the battery pack; wherein the operating parameters include the temperature, voltage and current of the battery pack; The sensing module is used to record the vehicle's driving parameters and the temperature inside and outside the driver's cab; wherein, the driving parameters include driving speed, driving acceleration, average vehicle speed, number of braking operations and single start-up time; A heating module, connected to the battery pack, is used to heat the battery pack via a PTC heater and to inject a high-frequency pulsed current into the battery pack. A circulation module, connected to the battery pack, is used to transfer waste heat generated by the heat pump to the battery pack; the circulation module also includes a distribution device for determining the proportion of waste heat transferred to the battery pack. The analysis module, together with the acquisition module and the sensing module, is used to determine whether the thermal management of the battery pack is qualified based on the operating parameters, and, if it is not qualified, to generate several instructions to adjust the corresponding parameters according to the determined reasons; the analysis module is also used to correct the corresponding parameters in each instruction based on the driving parameters, including the heating power of the PTC heater, the pulse current amplitude in the pulse heating mode and the proportion of residual heat delivered to the battery pack; A control module, which is connected to the heating module, the circulation module and the analysis module, is used to control each module to adjust according to the adjustment instructions generated by the analysis module.

[0007] Furthermore, the analysis module calculates the temperature rise-energy consumption ratio using the following formula to determine whether the thermal management of the battery pack is qualified:

[0008] Wherein, k represents the temperature rise-energy consumption ratio, T represents the temperature of the battery pack at the end of the monitoring period, and T0 represents the temperature of the battery pack at the beginning of the same monitoring period; T a Q represents the preset reference temperature. 额定 The rated capacity of the battery is represented by τ, which represents any instantaneous moment between the start and end times during the monitoring period, and I(τ) represents the charging and discharging current. This represents the cumulative charging and discharging current from time 0 to time t.

[0009] Furthermore, the analysis module is also used to determine whether the thermal management of the battery pack is qualified based on the temperature rise-energy consumption ratio, and, if it is not qualified, to determine the reason for the failure of the thermal management of the battery pack based on the vehicle dynamic load index, wherein the vehicle dynamic load index is obtained by the driving acceleration, the number of braking, the average vehicle speed, and the indoor and outdoor temperatures during the monitoring period.

[0010] Furthermore, the analysis module calculates the vehicle dynamic load index using the following formula:

[0011] Where S represents the vehicle dynamic load index, a represents the driving acceleration, and a max N represents the preset maximum vehicle acceleration; T represents the length of the monitoring period; N represents the maximum vehicle acceleration. brk f represents the number of braking operations during the monitoring period. max Indicates the preset maximum braking frequency; v avg v represents the average vehicle speed during the monitoring period. ref Indicates the preset vehicle speed; T cab Indicates the temperature inside the driver's cab, T amb Indicates the outside temperature of the driver's cab, ΔT max The preset maximum temperature difference is represented by α, β, γ, and δ, respectively. α represents the weighting coefficient of the driving acceleration, β represents the weighting coefficient of the number of braking operations, γ represents the weighting coefficient of the average vehicle speed, and δ represents the weighting coefficient of the temperature difference between the driver's cabin and the outside. α+β+γ+δ=1. The temperature difference between the driver's cabin and the outside is the difference between the temperature inside the driver's cabin and the temperature outside the driver's cabin.

[0012] Furthermore, the analysis module is also used to determine the cause of the thermal management failure of the battery pack based on the vehicle dynamic load index, and generate corresponding processing instructions based on the determined cause. The processing instructions include: starting the PTC heater for heating, starting the PTC heater in combination with pulse heating for heating, or transferring the waste heat generated by the heat pump to the battery pack through the circulation module.

[0013] Furthermore, the analysis module is also used to increase the heating power of the PTC heater according to the temperature difference between the driver's cabin and the outside during the monitoring period, and the increase in heating power is positively correlated with the temperature difference between the driver's cabin and the outside.

[0014] Furthermore, the analysis module is also used to adjust the pulse current amplitude in the pulse heating method according to the temperature difference of the battery pack during the monitoring period, and the pulse current amplitude is positively correlated with the temperature difference of the battery pack. Wherein, the pulse current amplitude refers to the maximum value of the pulse current flowing through the battery during pulse heating; the battery pack temperature difference refers to the temperature of the battery pack at the beginning and the end of the monitoring period.

[0015] Furthermore, the analysis module is also used to reduce the heating power of the PTC heater according to the amplitude of the pulse current, and the reduction in the heating power of the PTC heater is positively correlated with the amplitude of the pulse current.

[0016] Furthermore, the analysis module is also used to increase the proportion of waste heat delivered to the battery pack based on the difference between the target temperature and the current temperature of the battery pack, and the increase in the proportion of waste heat delivered to the battery pack is positively correlated with the difference between the target temperature and the current temperature of the battery pack.

[0017] Furthermore, the analysis module is also used to issue a command to start the PTC heater and pulse heating method in combination if the thermal management of the battery pack is still unqualified after adjusting the proportion of waste heat delivered to the battery pack.

[0018] Compared with existing technologies, the beneficial effects of this invention are as follows: This invention constructs a new energy vehicle battery thermal management system through modular design, linking the battery pack, acquisition module, sensing module, heating module, circulation module, analysis module, and control module. By integrating three heating methods—PTC heating, pulse heating, and heat pump waste heat utilization—and automatically determining and switching between the three heating modes based on the vehicle's dynamic load index and the temperature difference in the driver's cab, it overcomes the shortcomings of existing technologies that only use a single heating method. It achieves adaptive identification and dynamic adjustment of the system, improves the adaptive temperature control capability and energy efficiency of the thermal management system in a wide temperature range, thereby improving the battery's operating temperature conditions in low-temperature environments and ensuring battery life and vehicle range.

[0019] Furthermore, the analysis module of this invention determines whether the thermal management of the battery pack is qualified based on the calculated temperature rise-energy consumption ratio. By comparing the temperature rise-energy consumption ratio with a pre-stored preset temperature rise-energy consumption ratio, compared with a single temperature threshold comparison, it effectively avoids misjudgment and omission caused by a single judgment standard, further improving the adaptive temperature control capability and energy efficiency level of the thermal management system in a wide temperature range, thereby improving the battery's operating temperature conditions in low-temperature environments and ensuring battery life and vehicle range.

[0020] Furthermore, the analysis module of this invention determines the cause of thermal management failure of the battery pack based on the calculated vehicle dynamic load index. By integrating multi-dimensional driving parameters such as acceleration, braking frequency, average vehicle speed, and temperature difference between the interior and exterior of the driver's cab into a comprehensive index to determine the thermal load status, it effectively improves the accuracy of locating the cause of failure. Based on the determined cause, it generates corresponding processing instructions, further enhancing the adaptive temperature control capability and energy efficiency of the thermal management system in a wide temperature range. This improves the battery's operating temperature conditions in low-temperature environments, ensuring battery life and vehicle range.

[0021] Furthermore, the analysis module of this invention increases the heating power of the PTC heater based on the temperature difference between the interior and exterior of the driver's cab during the monitoring period, so that the PTC heating power can be dynamically adjusted with changes in ambient temperature. When the temperature difference increases, the power should be increased to quickly compensate for heat loss, and when the temperature difference decreases, the heating power should be reduced simultaneously to reduce unnecessary power consumption and avoid energy waste caused by overheating. This further improves the adaptive temperature control capability and energy efficiency of the thermal management system in a wide temperature range, thereby improving the battery's operating temperature conditions in low-temperature environments and ensuring battery life and vehicle range.

[0022] Furthermore, the analysis module of this invention adjusts the pulse current amplitude in the pulse heating method according to the battery pack temperature difference during the monitoring period, so that the pulse heating intensity can be adaptively adjusted according to the actual battery temperature. The larger the battery pack temperature difference, the more the battery is cooling down during the period, and the pulse current amplitude is automatically increased to accelerate internal heat generation. When the battery pack temperature difference is small, the pulse current amplitude is reduced accordingly to avoid energy waste caused by overheating. This further improves the adaptive temperature control capability and energy efficiency of the thermal management system in a wide temperature range, thereby improving the battery's operating temperature conditions in low-temperature environments and ensuring battery life and vehicle range.

[0023] Furthermore, the analysis module of the present invention reduces the heating power of the PTC heater according to the actual adjustment range of the pulse current amplitude. When the pulse heating and the PTC heating work together, the advantages of the high efficiency and relatively low energy consumption of the pulse heating are fully utilized to reduce the heating power of the PTC heater and reduce power consumption. This further improves the adaptive temperature control capability and energy efficiency of the thermal management system in a wide temperature range, thereby improving the battery's operating temperature conditions in low-temperature environments and ensuring battery life and vehicle range.

[0024] Furthermore, the analysis module of this invention increases the proportion of waste heat delivered to the battery pack based on the difference between the target temperature and the current temperature of the battery pack, thereby accelerating the rapid heating of the battery pack. The greater the difference between the target temperature and the current temperature, the more the battery pack needs to be heated. At this time, the waste heat allocation ratio is automatically increased to direct more heat pump waste heat to the battery pack to accelerate heating. When the battery pack approaches the target temperature, the waste heat allocation ratio is reduced accordingly to avoid overheating, further improving the waste heat utilization efficiency and reducing the additional energy consumption of PTC or pulse heating. This further enhances the adaptive temperature control capability and energy efficiency of the thermal management system in a wide temperature range, thereby improving the battery's operating temperature conditions in low-temperature environments and ensuring battery life and vehicle range.

[0025] Furthermore, if the analysis module of this invention determines that the thermal management of the battery pack is unqualified even after adjusting the proportion of waste heat delivered to the battery pack, it issues a command to activate a combination of PTC heater and pulse heating. Compared with the prior art, which activates all heating methods simultaneously from the beginning, this setting allows the heat pump waste heat, PTC heating, and pulse heating to form a progressive synergy. PTC and pulse heating are automatically added as supplementary heat sources only when waste heat alone cannot meet the battery pack's heating requirements. This reduces unnecessary energy consumption and ensures sufficient heating power in extreme scenarios such as extreme cold or severe battery cooling. It further improves the thermal management system's adaptive temperature control capability and energy efficiency over a wide temperature range, thereby improving the battery's operating temperature conditions in low-temperature environments and ensuring battery life and vehicle range. Attached Figure Description

[0026] Figure 1 This is a system architecture diagram of the new energy vehicle battery thermal management system described in this invention; Figure 2 This is a flowchart of the analysis module of the present invention determining whether the thermal management of the battery pack is qualified based on the temperature rise-energy consumption ratio; Figure 3 This is a flowchart of the analysis module of the present invention determining the reasons for the failure of thermal management of the battery pack based on the vehicle dynamic load index; Figure 4 This is a flowchart illustrating how the analysis module of the present invention adjusts the heating power of the PTC heater based on the temperature difference between the driver's cab and the outside during the monitoring period. Figure 5 This is a flowchart illustrating how the analysis module of the present invention adjusts the pulse current amplitude in the pulse heating method based on the battery pack temperature difference during the monitoring period. Figure 6 This is a flowchart illustrating how the analysis module of the present invention adjusts the proportion of waste heat delivered to the battery pack based on the difference between the target temperature and the current temperature of the battery pack. Detailed Implementation

[0027] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0028] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0029] It should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0030] Please see Figure 1 The diagram shown is a system architecture diagram of the new energy vehicle battery thermal management system of the present invention. The system of the present invention includes a battery pack, a data acquisition module, a sensing module, a heating module, a circulation module, an analysis module, and a control module. The battery pack includes a plurality of interconnected cells; wherein the cells can receive high-frequency pulse current and generate heat using their own internal resistance to achieve pulse heating. The acquisition module is used to monitor and acquire the operating parameters of the battery pack and the current and voltage of the PTC heater; wherein the operating parameters include the temperature, voltage and current of the battery pack; The sensing module is used to record the vehicle's driving parameters and the temperature inside and outside the driver's cab; wherein, the driving parameters include driving speed, driving acceleration, average vehicle speed, number of braking operations, and single start-up duration; The heating module is connected to the battery pack and is used to heat the battery pack via a PTC heater and to inject a high-frequency pulse current into the battery pack. The circulation module, which is connected to the battery pack, is used to transfer the waste heat generated by the heat pump to the battery pack; the circulation module also includes a distribution device for determining the proportion of waste heat transferred to the battery pack. The analysis module, together with the acquisition module and the sensing module, is used to determine whether the thermal management of the battery pack is qualified based on the operating parameters, and, if it is not qualified, to generate several instructions to adjust the corresponding parameters according to the determined reasons; the analysis module is also used to correct the corresponding parameters in each instruction based on the driving parameters, including the heating power of the PTC heater, the pulse current amplitude in the pulse heating mode and the proportion of waste heat delivered to the battery pack; The control module is connected to the heating module, the circulation module and the analysis module, and is used to control each module to adjust according to the adjustment instructions generated by the analysis module.

[0031] Please see Figure 2 As shown, this is a flowchart illustrating the process by which the analysis module of the present invention determines whether the thermal management of the battery pack is qualified based on the temperature rise-energy consumption ratio. The process by which the analysis module of the present invention determines whether the thermal management of the battery pack is qualified based on the temperature rise-energy consumption ratio includes: Obtain the operating parameters collected by the acquisition module; The temperature rise-energy ratio is calculated using the following formula:

[0032] Wherein, k represents the temperature rise-energy consumption ratio, T represents the temperature of the battery pack at the end of the monitoring period, and T0 represents the temperature of the battery pack at the beginning of the same monitoring period; T a Q represents the preset reference temperature. 额定 The rated capacity of the battery is represented by τ, which represents any instantaneous moment between the start and end times during the monitoring period, and I(τ) represents the charging and discharging current. This represents the cumulative charging and discharging current from time 0 to time t. The temperature rise-energy consumption ratio is compared with a pre-stored preset temperature rise-energy consumption ratio; If the temperature rise-energy consumption ratio is less than or equal to the preset temperature rise-energy consumption ratio, the thermal management of the battery pack is deemed qualified, and monitoring continues. If the temperature rise-energy consumption ratio is greater than the preset temperature rise-energy consumption ratio, the thermal management of the battery pack is deemed unqualified. The cause of the unqualification is determined based on the vehicle dynamic load index, and a corresponding adjustment command is issued. The vehicle dynamic load index is obtained by measuring the driving acceleration, the number of braking operations, the average vehicle speed, and the indoor and outdoor temperatures during the monitoring period. The monitoring period is from when the vehicle starts until the indoor temperature reaches the expected value while the vehicle is in motion.

[0033] In this embodiment, the preset reference temperature is set to 20°C, and the preset temperature rise-energy consumption ratio is set to 0.7. It is understood that this embodiment of the invention does not impose specific restrictions on the values ​​of the preset reference temperature and the preset temperature rise-energy consumption ratio, as long as the system can determine whether the thermal management of the battery pack is qualified by comparing the temperature rise-energy consumption ratio with the preset temperature rise-energy consumption ratio.

[0034] Please see Figure 3 As shown, this is a flowchart illustrating how the analysis module of the present invention determines the cause of the thermal management failure of the battery pack based on the vehicle dynamic load index. The process by which the analysis module determines the cause of the thermal management failure of the battery pack based on the vehicle dynamic load index and issues corresponding processing instructions includes: Obtain the driving parameters recorded by the sensing module; The vehicle dynamic load index is calculated using the following formula:

[0035] Where S represents the vehicle dynamic load index, a represents the driving acceleration, and a max N represents the preset maximum vehicle acceleration; T represents the length of the monitoring period; N represents the maximum vehicle acceleration. brk f represents the number of braking operations during the monitoring period. max Indicates the preset maximum braking frequency; v avg v represents the average vehicle speed during the monitoring period. ref Indicates the preset vehicle speed; T cab Indicates the temperature inside the driver's cab, T amb Indicates the outside temperature of the driver's cab, ΔT max The preset maximum temperature difference is represented by α, β, γ, and δ, respectively. α represents the weighting coefficient of the driving acceleration, β represents the weighting coefficient of the number of braking operations, γ represents the weighting coefficient of the average vehicle speed, and δ represents the weighting coefficient of the temperature difference between the driver's cabin and the outside. α+β+γ+δ=1. The temperature difference between the driver's cabin and the outside is the difference between the temperature inside the driver's cabin and the temperature outside the driver's cabin. In this embodiment, the preset maximum vehicle acceleration is set to 4 m / s², the preset maximum braking frequency is set to 6 times / minute, the preset vehicle speed is set to 80 km / h, and the preset maximum temperature difference is set to 30°C. It is understood that this embodiment of the invention does not impose specific restrictions on the preset maximum vehicle acceleration, preset maximum braking frequency, preset vehicle speed, and preset maximum temperature difference, as long as the system can calculate the vehicle dynamic load index using the preset maximum vehicle acceleration, preset maximum braking frequency, preset vehicle speed, and preset maximum temperature difference. The vehicle dynamic load index is compared with the pre-stored preset vehicle dynamic load index. If the vehicle dynamic load index is less than or equal to the preset vehicle dynamic load index, it is determined that the vehicle has just started and has not yet moved, and the analysis module issues a command to start the PTC heater for heating. If the vehicle dynamic load index is greater than the preset vehicle dynamic load index, it is determined that the vehicle has been driven. The difference between the current temperature in the driver's cab and the target temperature set in the driver's cab is calculated and recorded as the temperature difference in the driver's cab. The temperature difference inside the driver's cab is compared with the pre-stored preset temperature difference; If the temperature difference in the driver's cab is greater than the preset temperature difference, it is determined that the vehicle has been driven but the temperature in the driver's cab has not reached the expected level. The analysis module then issues a command to start the PTC heater in combination with pulse heating. If the temperature difference inside the driver's cab is less than or equal to the preset temperature difference, it is determined that the vehicle has been driven and the temperature inside the driver's cab has reached the expected level. The analysis module then issues an instruction to transfer the waste heat generated by the heat pump to the battery pack through the circulation module.

[0036] In this embodiment, the preset vehicle dynamic load index is assigned a value of 0.2, and the preset temperature difference is assigned a value of 2℃. It is understood that this embodiment of the invention does not impose specific restrictions on the values ​​of the preset vehicle dynamic load index and the preset temperature difference, as long as the system can determine the cause of the thermal management of the battery pack by comparing the vehicle dynamic load index with the preset vehicle dynamic load index and comparing the temperature difference in the driver's cab with the preset temperature difference, and issue corresponding processing instructions.

[0037] Please refer to Figure 4 As shown, this is a flowchart of the analysis module of the present invention adjusting the heating power of the PTC heater according to the temperature difference between the driver's cab and the outside during the monitoring period. The process includes: The sensor module records the indoor and outdoor temperatures of the driver's cabin. Calculate the temperature difference between the driver's cabin and the outside during the monitoring period; The temperature difference between the driver's cabin and the outside is compared with a pre-stored preset temperature difference between the driver's cabin and the outside; If the temperature difference between the driver's cabin and the outside is less than or equal to the first preset temperature difference between the driver's cabin and the outside, the analysis module determines to adjust the correction coefficient λ to the corresponding value using the first preset adjustment coefficient b1. <b1≤1.2; If the temperature difference between the driver's cabin and the outside is greater than the first preset temperature difference between the driver's cabin and the outside is less than or equal to the second preset temperature difference between the driver's cabin and the outside, the analysis module determines to adjust the correction coefficient λ to the corresponding value using the second preset adjustment coefficient b2, b1 <b2≤1.5; If the temperature difference between the driver's cabin and the outside is greater than the second preset temperature difference between the driver's cabin and the outside, the analysis module determines to adjust the correction coefficient λ to the corresponding value using the third preset adjustment coefficient b3, b2. <b3≤1.8; When the analysis module determines that the correction coefficient λ is adjusted to the corresponding value using the j-th preset adjustment coefficient bj, j=1, 2, 3, the adjusted correction coefficient λ'=λ×bj is set.

[0038] In this embodiment, the first preset temperature difference between the driver's cabin and the outside is assigned a value of 10℃, the second preset temperature difference between the driver's cabin and the outside is assigned a value of 25℃, the first preset adjustment coefficient is assigned a value of 1.11, the second preset adjustment coefficient is assigned a value of 1.34, and the third preset adjustment coefficient is assigned a value of 1.65. It is understood that this embodiment of the invention does not impose specific restrictions on the values ​​of the first preset temperature difference between the driver's cabin and the outside, the second preset temperature difference between the driver's cabin and the outside, the first preset adjustment coefficient, the second preset adjustment coefficient, and the third preset adjustment coefficient, as long as the system can adjust the correction coefficient λ by comparing the temperature difference between the driver's cabin and the outside with the preset temperature difference between the driver's cabin and the outside.

[0039] Please refer to Figure 5 As shown, this is a flowchart illustrating how the analysis module of the present invention adjusts the pulse current amplitude in the pulse heating method based on the battery pack temperature difference during the monitoring period. The process includes: The temperature of the battery pack monitored and collected by the acquisition module is obtained; Calculate the temperature of the battery pack at the beginning of the monitoring period and the temperature of the battery pack at the end of the monitoring period, and record it as the temperature difference of the battery pack. The temperature difference of the battery pack is compared with the preset temperature difference of the battery pack. If the temperature difference of the battery pack is less than or equal to the first preset temperature difference of the battery pack, the analysis module determines to adjust the correction coefficient η to the corresponding value using the first preset adjustment coefficient c1. <c1≤1.1; If the temperature difference of the battery pack is greater than the first preset battery pack temperature difference and less than or equal to the second preset battery pack temperature difference, the analysis module determines to adjust the correction coefficient η to the corresponding value using the second preset adjustment coefficient c2, c1 <c2≤1.3; If the temperature difference of the battery pack is greater than the second preset temperature difference of the battery pack, the analysis module determines to adjust the correction coefficient η to the corresponding value using the third preset adjustment coefficient c3, c2. <c3≤1.5; When the analysis module determines that the correction coefficient η is adjusted to the corresponding value using the m-th preset adjustment coefficient cm, m=1, 2, 3, the adjusted correction coefficient η'=η×cm is set.

[0040] In this embodiment, the first preset battery pack temperature difference is assigned a value of 3°C, the second preset battery pack temperature difference is assigned a value of 8°C, the first preset adjustment coefficient is assigned a value of 1.05, the second preset adjustment coefficient is assigned a value of 1.23, and the third preset adjustment coefficient is assigned a value of 1.41. It is understood that this embodiment of the invention does not impose specific limitations on the values ​​of the first preset battery pack temperature difference, the second preset battery pack temperature difference, the first preset adjustment coefficient, the second preset adjustment coefficient, and the third preset adjustment coefficient, as long as the system can adjust the correction coefficient η by comparing the battery pack temperature difference with the preset battery pack temperature difference.

[0041] Specifically, the pulse current amplitude refers to the maximum value of the pulse current flowing through the battery during pulse heating.

[0042] Specifically, the analysis module is also used to reduce the heating power of the PTC heater according to the actual adjustment range of the pulse current amplitude, and to calculate the heating power of the PTC heater using the following formula:

[0043] Among them, P PTC I represents the heating power of the PTC heater. PTC0 This indicates the current of the PTC heater before the pulse heating mode is activated, in V. PTC0 This indicates the voltage of the PTC heater before the pulse heating mode is activated, μ represents the preset balance adjustment factor and 0 < μ ≤ 1, I pulse I represents the current pulse current amplitude. pulse_max This indicates the maximum permissible pulse current amplitude.

[0044] Please refer to Figure 6 As shown, this is a flowchart illustrating how the analysis module of the present invention adjusts the proportion of waste heat supplied to the battery pack based on the difference between the target temperature and the current temperature of the battery pack. The process includes: The temperature of the battery pack monitored and collected by the acquisition module is obtained; Calculate the difference between the preset target temperature of the battery pack and the current temperature, and record it as the target temperature difference of the battery pack; The target temperature difference of the battery pack is compared with the preset target temperature difference of the battery pack. If the target temperature difference of the battery pack is less than or equal to the first preset target temperature difference of the battery pack, the analysis module determines to adjust the correction coefficient ω to the corresponding value using the first preset adjustment coefficient d1. <d1≤1.3; If the target temperature difference of the battery pack is greater than the first preset target temperature difference of the battery pack and less than or equal to the second preset target temperature difference of the battery pack, the analysis module determines to adjust the correction coefficient ω to the corresponding value using the second preset adjustment coefficient d2, d1 <d2≤1.6; If the target temperature difference of the battery pack is less than or equal to the second preset target temperature difference of the battery pack, the analysis module determines to adjust the correction coefficient ω to the corresponding value using the third preset adjustment coefficient d3, d2. <d3≤1.9; When the analysis module determines that the correction coefficient ω is adjusted to the corresponding value using the nth preset adjustment coefficient dn, n=1, 2, 3, the adjusted correction coefficient ω'=ω×dn is set.

[0045] In this embodiment, the first preset target temperature difference of the battery pack is assigned a value of 10℃, the second preset target temperature difference of the battery pack is assigned a value of 20℃, the first preset adjustment coefficient is assigned a value of 1.21, the second preset adjustment coefficient is assigned a value of 1.49, and the third preset adjustment coefficient is assigned a value of 1.77. It is understood that this embodiment of the invention does not impose specific limitations on the values ​​assigned to the first preset target temperature difference of the battery pack, the second preset target temperature difference of the battery pack, the first preset adjustment coefficient, the second preset adjustment coefficient, and the third preset adjustment coefficient, as long as the system can adjust the correction coefficient ω by comparing the target temperature difference of the battery pack with the preset target temperature difference of the battery pack.

[0046] Specifically, the analysis module is also used to issue a command to start the PTC heater and pulse heating method in combination if the thermal management of the battery pack is still unqualified after adjusting the proportion of waste heat delivered to the battery pack.

[0047] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

[0048] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A thermal management system for a new energy vehicle battery, characterized in that, include: A battery pack comprising a plurality of interconnected cells; wherein the cells can receive high-frequency pulse current and generate heat using their own internal resistance to achieve pulse heating; A data acquisition module is used to monitor and acquire the operating parameters of the battery pack; wherein the operating parameters include the temperature, voltage and current of the battery pack; The sensing module is used to record the vehicle's driving parameters and the temperature inside and outside the driver's cab; wherein, the driving parameters include driving speed, driving acceleration, average vehicle speed, number of braking operations and single start-up time; A heating module, connected to the battery pack, is used to heat the battery pack via a PTC heater and to inject a high-frequency pulsed current into the battery pack. A circulation module, connected to the battery pack, is used to transfer waste heat generated by the heat pump to the battery pack; the circulation module also includes a distribution device for determining the proportion of waste heat transferred to the battery pack. The analysis module, together with the acquisition module and the sensing module, is used to determine whether the thermal management of the battery pack is qualified based on the operating parameters, and, if it is not qualified, to generate several instructions to adjust the corresponding parameters according to the determined reasons; the analysis module is also used to correct the corresponding parameters in each instruction based on the driving parameters, including the heating power of the PTC heater, the pulse current amplitude in the pulse heating mode and the proportion of residual heat delivered to the battery pack; A control module, which is connected to the heating module, the circulation module and the analysis module, is used to control each module to adjust according to the adjustment instructions generated by the analysis module.

2. The new energy vehicle battery thermal management system according to claim 1, characterized in that, The analysis module calculates the temperature rise-energy consumption ratio using the following formula to determine whether the thermal management of the battery pack is qualified: ； Wherein, k represents the temperature rise-energy consumption ratio, T represents the temperature of the battery pack at the end of the monitoring period, and T0 represents the temperature of the battery pack at the beginning of the same monitoring period; T a Q represents the preset reference temperature. 额定 The rated capacity of the battery is represented by τ, which represents any instantaneous moment between the start and end times during the monitoring period, and I(τ) represents the charging and discharging current. This represents the cumulative charging and discharging current from time 0 to time t.

3. The new energy vehicle battery thermal management system according to claim 2, characterized in that, The analysis module is also used to determine whether the thermal management of the battery pack is qualified based on the temperature rise-energy consumption ratio, and, if it is not qualified, to determine the reason for the failure of the thermal management of the battery pack based on the vehicle dynamic load index, wherein the vehicle dynamic load index is obtained by the driving acceleration, the number of braking, the average vehicle speed, and the indoor and outdoor temperatures of the driver's cab during the monitoring period.

4. The new energy vehicle battery thermal management system according to claim 3, characterized in that, The analysis module calculates the vehicle dynamic load index using the following formula: ； Where S represents the vehicle dynamic load index, a represents the driving acceleration, and a max N represents the preset maximum vehicle acceleration; T represents the length of the monitoring period; N represents the maximum vehicle acceleration. brk f represents the number of braking operations during the monitoring period. max Indicates the preset maximum braking frequency; v avg v represents the average vehicle speed during the monitoring period. ref Indicates the preset vehicle speed; T cab Indicates the temperature inside the driver's cab, T amb Indicates the outside temperature of the driver's cab, ΔT max The preset maximum temperature difference is represented by α, β, γ, and δ, respectively. α represents the weighting coefficient of the driving acceleration, β represents the weighting coefficient of the number of braking operations, γ represents the weighting coefficient of the average vehicle speed, and δ represents the weighting coefficient of the temperature difference between the driver's cabin and the outside. α+β+γ+δ=1. The temperature difference between the driver's cabin and the outside is the difference between the temperature inside the driver's cabin and the temperature outside the driver's cabin.

5. The new energy vehicle battery thermal management system according to claim 4, characterized in that, The analysis module is also used to determine the cause of the thermal management failure of the battery pack based on the vehicle dynamic load index, and generate corresponding processing instructions based on the determined cause. The processing instructions include: starting the PTC heater for heating, starting the PTC heater and pulse heating in combination, or transferring the waste heat generated by the heat pump to the battery pack through the circulation module.

6. The new energy vehicle battery thermal management system according to claim 5, characterized in that, The analysis module is also used to increase the heating power of the PTC heater according to the temperature difference between the driver's cabin and the outside during the monitoring period, and the increase in heating power is positively correlated with the temperature difference between the driver's cabin and the outside.

7. The new energy vehicle battery thermal management system according to claim 5, characterized in that, The analysis module is also used to adjust the pulse current amplitude in the pulse heating method according to the temperature difference of the battery pack during the monitoring period, and the pulse current amplitude is positively correlated with the temperature difference of the battery pack. Wherein, the pulse current amplitude refers to the maximum value of the pulse current flowing through the battery during pulse heating; the battery pack temperature difference refers to the temperature of the battery pack at the beginning and the end of the monitoring period.

8. The new energy vehicle battery thermal management system according to claim 7, characterized in that, The analysis module is also used to reduce the heating power of the PTC heater according to the actual adjustment range of the pulse current amplitude, and the reduction range of the heating power of the PTC heater is positively correlated with the pulse current amplitude.

9. The new energy vehicle battery thermal management system according to claim 5, characterized in that, The analysis module is also used to increase the proportion of waste heat delivered to the battery pack based on the difference between the target temperature and the current temperature of the battery pack, and the increase in the proportion of waste heat delivered to the battery pack is positively correlated with the difference between the target temperature and the current temperature of the battery pack.

10. The new energy vehicle battery thermal management system according to claim 9, characterized in that, The analysis module is also used to issue a command to start the PTC heater and pulse heating in combination if the thermal management of the battery pack is still deemed unqualified after adjusting the proportion of waste heat delivered to the battery pack.

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