Battery thermal energy early warning control method, system and new energy vehicle

Abstract

A battery thermal energy early warning control method, a system (1) and a new energy vehicle. The control method comprises: 1) setting a feedback current matrix of a battery module (2); 2) controlling charging and discharging of the battery module (2) on the basis of the feedback current matrix, and performing temperature control on a battery pack on the basis of the ambient temperature; 3) during the process of step 2), training and updating an SOC curve local model, fitting an SOC curve, when the SOC curve converges, determining that a battery is normal, and when the SOC curve diverges, determining that the battery is abnormal and sending out a first early warning signal; meanwhile, monitoring the temperature rise of the battery module (2), when the temperature rise speed is less than a third preset value, determining that the battery is normal, and when the temperature rise speed is greater than or equal to the third preset value, determining that the battery is abnormal and sending out a second early warning signal; when the first early warning signal and the second early warning signal are both valid, stopping charging and discharging, and sending out a fault early warning; and 4) during the process of step 2), if a working state exceeds a safety protection range, sending out a fault early warning, and initiating fire extinguishing and explosion prevention measures.

Description

Battery thermal energy early warning and control methods, systems and new energy vehicles Technical Field

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

[0002] With the popularization of new energy vehicles, battery technology has become a key research and development area. However, the thermal management systems of existing new energy vehicles are not precise and timely enough in terms of thermal regulation, and cannot effectively prevent battery thermal runaway and fire; the battery management system (BMS) does not monitor the battery status comprehensively and accurately enough, and cannot detect battery faults and safety hazards in a timely manner; the battery structure detection is not perfect enough, and cannot effectively prevent short circuits and fires caused by the battery being squeezed; the cell consistency management is not strict enough, resulting in inconsistent battery performance parameters and increasing safety hazards; and the temperature limit is not strict enough, causing the battery to experience performance degradation and thermal runaway when it exceeds the operating temperature range.

[0003] Therefore, batteries pose safety hazards such as fire and explosion when charging, in use, or when malfunctioning; this seriously affects the reliability and safety of new energy vehicles and poses a threat to the personal and property safety of users.

[0004] It should be noted that the above description of the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of the present invention and facilitating understanding by those skilled in the art. It should not be assumed that the above technical solutions are known to those skilled in the art simply because they have been described in the background section of this invention. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a battery thermal energy early warning control method, system and new energy vehicle to solve the safety problems existing in the use of batteries in the prior art.

[0006] To achieve the above and other related objectives, the present invention provides a battery thermal energy early warning control method, the battery thermal energy early warning control method comprising at least:

[0007] 1) Collect the status information of the battery module, set the feedback current matrix of the battery module based on the status information, and perform projection curve recognition on the feedback current matrix. The feedback current matrix includes the discharge rate at different temperatures and SOC states.

[0008] 2) The battery module is charged and discharged based on the feedback current matrix, and the battery pack is temperature controlled based on the ambient temperature. When the ambient temperature is less than a first preset value during charging, heating of the battery pack is started, and heating of the battery pack is stopped when the ambient temperature is greater than a second preset value; wherein, the first preset value is less than the second preset value.

[0009] 3) During the charging and discharging process of the battery module, a local model of the SOC curve is constructed and continuously updated based on the training results of key points. The SOC curve is fitted based on the updated local model. When the SOC curve converges, it is considered normal; when the SOC curve diverges, it is considered abnormal and a first warning signal is issued. Simultaneously, the temperature rise of the battery module is monitored. When the rate of temperature rise of the battery module is less than a third preset value, it is considered normal; when the rate of temperature rise of the battery module is greater than or equal to the third preset value, it is considered abnormal and a second warning signal is issued. When both the first and second warning signals are valid, the battery module stops charging and discharging and a fault warning is issued.

[0010] 4) If the working state of the battery module exceeds the safety protection range during the charging and discharging process, a fault warning will be issued and fire extinguishing and explosion prevention measures will be activated.

[0011] Optionally, the status information includes at least one of the following: external temperature of the battery module, internal temperature of the battery module, temperature of individual cells, voltage of individual cells, SOC status, and cell voltage difference.

[0012] Optionally, in the feedback current matrix, charging and discharging are not allowed when the temperature is below 0°C or above 65°C, or when the state of charge is above 90%.

[0013] When the state of charge is between 70% and 90%, the discharge rate tends to increase with increasing temperature.

[0014] When the state of charge is less than or equal to 70%, the discharge rate tends to increase with increasing temperature between 0℃ and 50℃; while the discharge rate tends to decrease with increasing temperature between 50℃ and 65℃.

[0015] Optionally, the solution method for the local model of the SOC curve is as follows:

[0016] 31) Establish a local model of the SOC curve that satisfies: in, β represents the training results for a single keypoint;

[0017] 32) Predict the initial key point region;

[0018] 33) Quickly search the area around the key points of the local model of the detected SOC curve to obtain the response curve;

[0019] 34) The selected key points are fitted using a quadratic function ε, which satisfies:

[0020] 35) Calculate the optimal solution of the quadratic function ε using mathematical methods, obtain the positions of each key point, and update the local model of the SOC curve;

[0021] 36) Repeat steps 33) to 35) to obtain the local SOC curves.

[0022] Optionally, under normal conditions, the SOC curve satisfies:

[0023] Under abnormal conditions, the SOC curve satisfies:

[0024] Where a and b are random continuous natural constants, and y is the function value of SOC, y∈[0,+∞).

[0025] Optionally, the temperature difference of the battery module is detected during a preset period of the battery module startup phase, thereby obtaining the rate at which the battery module heats up.

[0026] Alternatively, step 3 can be performed sequentially on each cell.

[0027] Optionally, the battery thermal energy early warning control method further includes: making an early warning judgment based on the actual detected temperature change of the battery module.

[0028] Optionally, the early warning judgment based on the actual detected temperature change of the battery module includes: obtaining the detected temperature from the thermal sensor in the battery module.

[0029] Alternatively, the thermal sensor is implemented using a heat sink, with a heat transfer medium introduced into the inlet and discharged from the outlet. The temperature change of the battery module attached to the heat sink can be obtained by the temperature change at the inlet or outlet of the heat sink.

[0030] To achieve the above and other related objectives, the present invention also provides a battery thermal energy early warning control system for implementing the above-described battery thermal energy early warning control method, wherein the battery thermal energy early warning control system includes at least:

[0031] The module includes a data acquisition module, an FCM control module, a fault warning module, and a safety protection module.

[0032] The acquisition module is used to collect the status information of the battery module and the ambient temperature.

[0033] The FCM control module is connected to the output of the acquisition module. Based on the information acquired by the acquisition module, it sets the feedback current matrix of the battery module, controls the charging and discharging of the battery module, and makes early warning judgments.

[0034] The fault warning module is connected to the output terminal of the FCM control module and issues a warning based on the warning signal output by the FCM control module.

[0035] The safety protection module is connected to the output of the acquisition module and the FCM control module. When the working state of the battery module exceeds the safety protection range, the fire extinguishing and explosion-proof device is activated.

[0036] Optionally, the acquisition module includes a thermal sensor, a voltage measuring instrument, a SOC calculation unit, and a differential pressure calculation unit;

[0037] The thermal sensors detect the ambient temperature, the external temperature of the battery module, the internal temperature of the battery module, and the temperature of each individual battery cell.

[0038] The SOC calculation unit calculates the state of charge of the battery module;

[0039] The voltage measuring instrument detects the voltage of each individual battery cell;

[0040] The differential pressure calculation unit is connected to the output terminal of the voltage measuring instrument and is used to calculate the differential pressure between two adjacent individual cells, and to monitor the total differential pressure across the battery module per unit time based on the differential pressure of each group of adjacent individual cells.

[0041] Optionally, the fault warning module includes a warning light for receiving the first warning signal and the second warning signal. When both the first warning signal and the second warning signal are valid, the warning light flashes to achieve a warning effect.

[0042] Alternatively, the warning light may be an LED light or a graphic in an app.

[0043] To achieve the above and other related objectives, the present invention also provides a new energy vehicle, the new energy vehicle comprising at least:

[0044] Vehicle body, battery module and the aforementioned thermal warning and control system;

[0045] The battery module and the thermal energy warning control system are installed in the vehicle body; the thermal energy warning control system is connected to the battery module and is used to provide thermal energy warnings for the battery module and control the safe charging and discharging of the battery module; the vehicle body operates based on the energy provided by the battery module.

[0046] As described above, the battery thermal energy early warning control method, system, and new energy vehicle of the present invention have the following beneficial effects:

[0047] This invention provides thermal energy early warning control for new energy vehicles based on FCM (Fuel Conduction Mode). While ensuring the safety protection system, it can effectively prevent the new energy vehicle battery from catching fire in FCM mode, thus improving the safety performance of new energy vehicles. At the same time, the system can also detect battery faults in a timely manner and take repair measures to ensure the normal operation of new energy vehicles. In addition, the implementation of this system does not require changes to the original battery structure and design, so it has high practicality and broad application prospects. Attached Figure Description

[0048] Figure 1 shows a schematic flowchart of the battery thermal energy early warning control method of the present invention.

[0049] Figure 2 shows a schematic diagram of the projection curve of the feedback current matrix of the present invention.

[0050] Figure 3 shows a schematic diagram of the heat sink temperature curve on the battery module of the present invention.

[0051] Figure 4 shows a schematic diagram of the battery thermal energy early warning control system of the present invention.

[0052] Figure 5 shows a schematic diagram of the structure of the new energy vehicle of the present invention.

[0053] Component Labeling Explanation: 1. Battery Thermal Warning and Control System; 11. Data Acquisition Module; 12. FCM Control Module; 13. Fault Warning Module; 14. Safety Protection Module; 2. Battery Module; 3. Vehicle Body. Detailed Implementation

[0054] The following specific examples 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. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0055] Please refer to Figures 1 to 5. It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the figures only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0056] As shown in Figure 1, the present invention provides a battery thermal energy early warning and control method, including:

[0057] 1) Collect the status information of the battery module, set the feedback current matrix of the battery module based on the status information, and identify the projection curve of the feedback current matrix. The feedback current matrix includes the discharge rate under different temperatures and SOC (State of charge).

[0058] Specifically, in this embodiment, the status information includes, but is not limited to, at least one of the following: external temperature of the battery module, internal temperature of the battery module, individual cell temperature, individual cell voltage, SOC status, and cell voltage difference. As an example, the external temperature, internal temperature, and individual cell temperature of the battery module are detected by a thermal sensor; the individual cell voltage is detected by a voltage measuring instrument; and the cell voltage difference is calculated by a voltage difference calculation unit, which sequentially acquires the voltages of two adjacent individual cells, denoted as U. j and U j+1 (where j is a natural number), by balancing the voltage difference ΔU(U) between adjacent individual cells in each group. i -U i+1 The total voltage difference ΔU across the battery module is monitored per unit time (calculated based on the connection relationship of each individual cell in the battery module, which will not be elaborated here); the SOC state is calculated by the SOC calculation unit, which calculates the SOC state based on the total voltage of the battery pack in the battery module, and the specific scalar is expressed as a percentage %.

[0059] It should be noted that the status information and the method of obtaining the status information can be set as needed and are not limited to this embodiment.

[0060] Specifically, the feedback current matrix (FCM) of the battery module is set based on the collected key information to ensure battery power safety. In this embodiment, in the feedback current matrix, charging and discharging are not allowed when the temperature is below 0°C or above 65°C, or when the state of charge (SOC) is above 90%. When the SOC is between 70% and 90%, the discharge rate increases with increasing temperature. When the SOC is less than or equal to 70%, the discharge rate increases with increasing temperature between 0°C and 50°C; and decreases with increasing temperature between 50°C and 65°C. As an example, the discharge rate settings at different temperatures and SOC states are as follows:

[0061] It should be noted that the specific temperature value, SOC value and corresponding discharge rate can be set according to actual needs and are not limited to this embodiment.

[0062] Specifically, the projection curve of the feedback current matrix is ​​identified, as shown in Figure 2.

[0063] 2) The battery module charging and discharging are controlled based on the feedback current matrix, and the battery pack temperature is controlled based on the ambient temperature. When the ambient temperature is less than the first preset value during charging, the heating of the battery pack is started, and the heating of the battery pack is stopped when the ambient temperature is greater than the second preset value; wherein, the first preset value is less than the second preset value.

[0064] Specifically, the battery module is charged and discharged within the parameter range set by the feedback current matrix (limiting the current and voltage) to ensure battery safety.

[0065] Specifically, during the charging and discharging process of the battery module, the battery pack temperature is also controlled based on the ambient temperature. In this embodiment, the battery module is used in a vehicle, so the ambient temperature is the temperature inside or outside the vehicle where the battery module is housed. In actual use, the ambient temperature is determined according to the application of the battery module. Further, the heating device installed on the battery module has a rated voltage of 220V and is activated during charging. The heating is activated when the ambient temperature is lower than a first preset value, and deactivated when the ambient temperature is higher than a second preset value. After the heating device is deactivated, the battery module cools naturally. In this embodiment, the first preset value is set to less than -10℃, including but not limited to -15℃, -20℃, -22℃, -25℃, and -30℃, and the second preset value is set to greater than 40℃, including but not limited to 45℃, 50℃, 55℃, and 58℃. In actual use, the first and second preset values ​​are set according to the actual application environment.

[0066] 3) During the charging and discharging process of the battery module, a local model of the SOC curve is constructed and continuously updated based on the training results of key points. The SOC curve is fitted based on the updated local model. When the SOC curve converges, it is considered normal; when the SOC curve diverges, it is considered abnormal and a first warning signal is issued. At the same time, the temperature rise of the battery module is monitored. When the temperature rise rate of the battery module is less than a third preset value, it is considered normal; when the temperature rise rate of the battery module is greater than or equal to the third preset value, it is considered abnormal and a second warning signal is issued. When both the first and second warning signals are valid, the battery module stops charging and discharging and a fault warning is issued.

[0067] Specifically, early warning judgments can be made based on model calculations or based on actual detected temperature changes in the battery module. One method can be chosen for early warning during operation. In this embodiment, both early warning methods are used to improve reliability, and a second early warning is achieved through a first early warning and a second early warning.

[0068] Specifically, in this embodiment, the method for realizing early warning judgment based on model calculation is as follows: First, solve the local model of the SOC curve:

[0069] 31) Establish a local model of the SOC curve that satisfies: in, And β are the training results for a single keypoint ( β and β are a set of input keypoint sequences, respectively.

[0070] 32) Expected initial key point area.

[0071] 33) Quickly search the area around the key points of the local model of the detected SOC curve to obtain the response curve.

[0072] 34) The selected key points are fitted using a quadratic function ε, which satisfies:

[0073] 35) Calculate the optimal solution of the quadratic function ε using mathematical methods, obtain the positions of each key point, and update the local model of the SOC curve.

[0074] 36) Repeat steps 33) to 35) to obtain the local SOC curves. The number of repetitions should be based on whether convergence and divergence can be demonstrated, and there is no limit to the number of repetitions.

[0075] Then, the local model of each SOC curve is fitted to obtain the SOC curve. After a set number of iterations (repetitions), if the fitted function converges, it indicates that the battery is working normally; if it diverges, it indicates that the battery is not working properly. As an example, under normal conditions (SOC curve convergence), the SOC curve satisfies:

[0076] Under abnormal conditions (SOC curve diverges), the SOC curve satisfies:

[0077] Where a and b are random continuous natural constants, and y is the function value of SOC, y∈[0,+∞).

[0078] Specifically, in this embodiment, the method for early warning judgment based on the actual detected temperature change of the battery module is as follows: The detected temperature is obtained from the thermal sensor in the battery module. As an example, the thermal sensor is implemented using a heat sink. The heat transfer medium is introduced into the heat sink's inlet and discharged from its outlet. The temperature change of the battery module attached to the heat sink can be obtained by observing the temperature change at the inlet or outlet of the heat sink. As shown in Figure 3, the temperature difference of the battery module is detected within a preset time period during the battery module's startup phase (in this example, the preset time period is 0s to 50s during the startup phase). The temperature difference and the duration of the preset time period represent the rate of temperature rise of the battery module. If the rate of temperature rise is less than a third preset value, it indicates normal operation; if the rate of temperature rise is greater than or equal to the third preset value, it indicates an abnormality. The third preset value can be set according to actual needs and will not be elaborated here.

[0079] Specifically, in this embodiment, the battery module is controlled to stop charging and discharging when both the first and second warning signals are valid. In actual use, when the warning judgment is based solely on model calculations, the battery module is controlled to stop charging and discharging when the first warning signal is valid; when the warning judgment is based solely on the actual detected temperature change of the battery module, the battery module is controlled to stop charging and discharging when the second warning signal is valid. As an example, the fault warning is implemented using a flashing warning light to indicate the occurrence of the fault, facilitating subsequent fault troubleshooting and repair.

[0080] Specifically, in this embodiment, step 3) is executed sequentially for each cell. After the current cell completes the early warning judgment, the pointer for executing the judgment is switched to the next cell, thereby realizing the monitoring of the entire battery module.

[0081] 4) If the working state of the battery module exceeds the safety protection range during the charging and discharging process, a fault warning will be issued and fire extinguishing and explosion prevention measures will be activated.

[0082] Specifically, this invention controls charging and discharging under the constraints of a feedback current matrix, ensuring safe battery operation. If the battery module's operating state exceeds the safety protection range under the constraints of the feedback current matrix, it indicates a risk of combustion or explosion. At this point, a fault warning is issued, and fire extinguishing and explosion-proof measures are initiated. As an example, the fault warning is implemented using a flashing warning light. Fire extinguishing and explosion-proof measures include, but are not limited to, fire extinguishing with a fire extinguisher and pressure relief valves for explosion prevention; these will not be elaborated upon here.

[0083] As shown in Figure 4, the present invention also provides a battery thermal energy early warning control system 1 for implementing the above-mentioned battery thermal energy early warning control method. The battery thermal energy early warning control system 1 includes:

[0084] The system includes a data acquisition module 11, an FCM control module 12, a fault warning module 13, and a safety protection module 14.

[0085] As shown in Figure 4, the acquisition module 11 is used to acquire the status information of the battery module and the ambient temperature.

[0086] Specifically, in this embodiment, the acquisition module 11 includes a thermal sensor, a voltage measuring instrument, a SOC calculation unit, and a differential pressure calculation unit. Each thermal sensor detects the ambient temperature, the external temperature of the battery module, the internal temperature of the battery module, and the temperature of a single battery cell. In one example, at least one first thermal sensor is located in the environment outside the battery module and connected to the battery module, capable of detecting the ambient temperature and the external temperature of the battery module; at least one second thermal sensor is located inside the battery module, capable of detecting the internal temperature of the battery module and the temperature of a single battery cell. The SOC calculation unit calculates the state of charge of the battery module and displays the calculated SOC value on the APP. Each voltage measuring instrument detects the voltage of each single battery cell. The differential pressure calculation unit is connected to the output terminal of each voltage measuring instrument and is used to calculate the differential pressure between two adjacent single batteries cells, and to balance the differential pressure ΔU(U) between adjacent single batteries in each group. j -U j+1 The total voltage difference ΔU across the battery module is monitored per unit time. For example, when each individual cell is connected in series, the total voltage difference is obtained by summing the voltage differences of adjacent individual cells in each group.

[0087] As shown in Figure 4, the FCM control module 12 is connected to the output terminal of the acquisition module 11. Based on the information acquired by the acquisition module 11, it sets the feedback current matrix of the battery module, controls the charging and discharging of the battery module, and makes early warning judgments.

[0088] Specifically, the FCM control module 12 is used to implement, but is not limited to, the feedback current matrix setting in step 1), the charge and discharge control and battery pack heating function in step 2), and the early warning judgment in step 3, which will not be elaborated here.

[0089] As shown in Figure 4, the fault warning module 13 is connected to the output terminal of the FCM control module 12 and issues a warning based on the warning signal output by the FCM control module 12.

[0090] Specifically, in this embodiment, the fault warning module 13 includes a warning light, which is an LED light or a graphic in the APP; the fault warning module 13 receives a first warning signal and a second warning signal, and when both the first warning signal and the second warning signal are valid, the warning light flashes to achieve the warning function. Once a fault warning is issued, subsequent fault diagnosis and repair can be initiated based on the acquisition module 11 and the FCM control module 12.

[0091] It should be noted that once the battery module's operating state exceeds the safety protection range, the first and second warning signals will be effective. Therefore, when the battery module's operating state exceeds the safety protection range, the warning light will flash and an alarm will be triggered.

[0092] As shown in Figure 4, the safety protection module 14 is connected to the output terminals of the acquisition module 11 and the FCM control module 12. When the working state of the battery module exceeds the safety protection range, the fire extinguishing and explosion-proof device is activated.

[0093] Specifically, the safety protection module 14 includes a fire extinguishing device and an explosion-proof device, wherein the fire extinguishing device and the explosion-proof device can be installed near the battery module as needed.

[0094] As shown in Figure 5, the present invention also provides a new energy vehicle, comprising:

[0095] The present invention comprises a thermal energy early warning control system 1, a battery module 2, and a vehicle body 3.

[0096] As shown in Figure 5, the battery module 2 and the thermal energy warning control system 1 are installed inside the vehicle body 3; the thermal energy warning control system 1 is connected to the battery module 2 and is used to provide thermal energy warnings for the battery module 2 and control the safe charging and discharging of the battery module 2; the vehicle body 3 operates based on the energy provided by the battery module 2.

[0097] Specifically, in this embodiment, the battery module 12 includes a battery pack and a thermal sensor. The battery pack consists of two or more individual battery cells (connected in series, parallel, or series-parallel), and each individual battery cell has the same material and performance. As an example, each individual battery cell uses a 60Ah ternary lithium battery; the thermal sensor is implemented using a heat sink.

[0098] This invention effectively improves cell consistency and reduces the risk of battery thermal runaway and fire by rationally sorting battery cells (with identical materials and performance), improving thermal management, and enhancing the comprehensive monitoring and balancing capabilities of the lithium-ion battery management system.

[0099] This invention enhances the stringency of temperature limits. By reasonably limiting temperatures, it effectively prevents the battery from experiencing performance degradation and thermal runaway when exceeding its operating temperature range, thereby improving battery safety and stability. Simultaneously, based on the FCM control module, it improves the adjustment accuracy and timeliness of the thermal management system; effectively regulating the battery's operating temperature prevents overheating during charging, thus enhancing battery safety performance.

[0100] This invention can also comprehensively monitor the working status of the battery, promptly detect battery faults and safety hazards, and take corresponding balancing measures to improve the safety and stability of the battery.

[0101] In summary, this invention provides a battery thermal energy early warning control method, system, and new energy vehicle, comprising: 1) collecting the state information of the battery module, setting a feedback current matrix of the battery module based on the state information, and identifying the projection curve of the feedback current matrix, wherein the feedback current matrix includes the discharge rate at different temperatures and SOC states; 2) controlling the charging and discharging of the battery module based on the feedback current matrix, and simultaneously controlling the temperature of the battery pack based on the ambient temperature, wherein heating of the battery pack is initiated when the ambient temperature is less than a first preset value during charging, and heating of the battery pack is stopped when the ambient temperature is greater than a second preset value; wherein the first preset value is less than the second preset value; 3) constructing a local model of the SOC curve during the charging and discharging process of the battery module. The system continuously updates the local model of the SOC curve based on the training results of key points. It then fits the SOC curve to the updated local model, determining normal operation when the SOC curve converges and abnormal operation when it diverges, issuing a first warning signal. Simultaneously, it monitors the temperature rise of the battery module. If the rate of temperature rise is less than a third preset value, it is considered normal; if the rate of temperature rise is greater than or equal to the third preset value, it is considered abnormal and a second warning signal is issued. When both the first and second warning signals are valid, the battery module stops charging and discharging, and a fault warning is issued. 4) During the charging and discharging process, if the battery module's operating state exceeds the safety protection range, a fault warning is issued and fire extinguishing and explosion-proof measures are activated. This invention provides thermal energy warning control for new energy vehicles based on the FCM state. While ensuring the safety protection system, it can effectively prevent new energy vehicle batteries from catching fire in the FCM state, improving the safety performance of new energy vehicles. Furthermore, the system can promptly detect battery faults and take repair measures, ensuring the normal operation of new energy vehicles. Moreover, the implementation of this system does not require changes to the original battery structure and design, thus possessing high practicality and broad application prospects. Therefore, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0102] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A battery thermal energy early warning and control method, characterized in that, The battery thermal energy early warning and control method includes at least the following: 1) Collect the status information of the battery module, set the feedback current matrix of the battery module based on the status information, and perform projection curve recognition on the feedback current matrix. The feedback current matrix includes the discharge rate at different temperatures and SOC states. 2) The battery module is charged and discharged based on the feedback current matrix, and the battery pack is temperature controlled based on the ambient temperature. When the ambient temperature is less than a first preset value during charging, heating of the battery pack is started, and heating of the battery pack is stopped when the ambient temperature is greater than a second preset value; wherein, the first preset value is less than the second preset value. 3) During the charging and discharging process of the battery module, a local model of the SOC curve is constructed and continuously updated based on the training results of key points. The SOC curve is fitted based on the updated local model. When the SOC curve converges, it is considered normal; when the SOC curve diverges, it is considered abnormal and a first warning signal is issued. Simultaneously, the temperature rise of the battery module is monitored. When the rate of temperature rise of the battery module is less than a third preset value, it is considered normal; when the rate of temperature rise of the battery module is greater than or equal to the third preset value, it is considered abnormal and a second warning signal is issued. When both the first and second warning signals are valid, the battery module stops charging and discharging and a fault warning is issued. 4) If the working state of the battery module exceeds the safety protection range during the charging and discharging process, a fault warning will be issued and fire extinguishing and explosion prevention measures will be activated.

2. The battery thermal energy early warning and control method according to claim 1, characterized in that: The status information includes at least one of the following: external temperature of the battery module, internal temperature of the battery module, temperature of a single cell, voltage of a single cell, SOC status, and cell voltage difference.

3. The battery thermal energy early warning and control method according to claim 1, characterized in that: In the feedback current matrix, charging and discharging are not allowed when the temperature is below 0°C or above 65°C, or when the state of charge is above 90%. When the state of charge is between 70% and 90%, the discharge rate tends to increase with increasing temperature. When the state of charge is less than or equal to 70%, the discharge rate tends to increase with increasing temperature between 0℃ and 50℃; while the discharge rate tends to decrease with increasing temperature between 50℃ and 65℃.

4. The battery thermal energy early warning and control method according to claim 1, characterized in that: The solution method for the local model of the SOC curve is as follows: 31) Establish a local model of the SOC curve that satisfies: in, β represents the training results for a single keypoint; 32) Expect the initial key point region; 33) Quickly search the area around the key points of the local model of the detected SOC curve to obtain the response curve; 34) The selected key points are fitted using a quadratic function ε, which satisfies: 35) Calculate the optimal solution of the quadratic function ε using mathematical methods, obtain the positions of each key point, and update the local model of the SOC curve; 36) Repeat steps 33) to 35) to obtain the local SOC curves.

5. The battery thermal energy early warning and control method according to claim 1, characterized in that: Under normal conditions, the SOC curve satisfies: Under abnormal conditions, the SOC curve satisfies: Where a and b are random continuous natural constants, and y is the function value of SOC, y∈[0,+∞).

6. The battery thermal energy early warning and control method according to claim 1, characterized in that: The temperature difference of the battery module is detected during a preset period of the battery module startup phase, thereby obtaining the rate at which the battery module heats up.

7. The battery thermal energy early warning and control method according to any one of claims 1, 4-6, characterized in that: Step 3 is executed sequentially for each battery cell.

8. The battery thermal energy early warning and control method according to claim 1, characterized in that: Also includes: Early warning judgments are made based on actual detected temperature changes in the battery module.

9. The battery thermal energy early warning and control method according to claim 8, characterized in that: The method of making early warning judgment based on the actual detected temperature change of the battery module includes: obtaining the detected temperature from the thermal sensor in the battery module.

10. The battery thermal energy early warning and control method according to claim 9, characterized in that: The thermal sensor is implemented using a heat sink. The heat sink has a heat transfer medium introduced into its inlet and an outlet that discharges the heat transfer medium. The temperature change of the battery module attached to the heat sink can be obtained by the temperature change at the inlet or outlet of the heat sink.

11. A battery thermal energy early warning control system, used to implement the battery thermal energy early warning control method as described in any one of claims 1-7, characterized in that, The battery thermal energy early warning and control system includes at least: The data acquisition module is used to collect status information of the battery module and ambient temperature. The FCM control module is connected to the output of the acquisition module. Based on the information acquired by the acquisition module, it sets the feedback current matrix of the battery module, controls the charging and discharging of the battery module, and makes early warning judgments. A fault warning module, connected to the output of the FCM control module, issues a warning based on the warning signal output by the FCM control module; and A safety protection module is connected to the output terminals of the acquisition module and the FCM control module. When the working state of the battery module exceeds the safety protection range, the fire extinguishing and explosion-proof device is activated.

12. The battery thermal energy early warning control system according to claim 8, characterized in that: The acquisition module includes: Multiple thermal sensors detect the ambient temperature, the external temperature of the battery module, the internal temperature of the battery module, and the temperature of individual battery cells, respectively. The SOC calculation unit calculates the state of charge of the battery module. Voltage measuring instruments are used to detect the voltage of individual battery cells; and The differential pressure calculation unit is connected to the output terminal of the voltage measuring instrument. It is used to calculate the differential pressure between two adjacent individual cells and to monitor the total differential pressure across the battery module per unit time based on the differential pressure of each group of adjacent individual cells.

13. The battery thermal energy early warning control system according to claim 8, characterized in that: The fault warning module includes a warning light for receiving the first warning signal and the second warning signal. When both the first warning signal and the second warning signal are valid, the warning light flashes to achieve a warning effect.

14. The battery thermal energy early warning control system according to claim 10, characterized in that: The warning light is an LED light or a graphic in the APP.

15. A new energy vehicle, characterized in that, The new energy vehicles include at least: The vehicle body, the battery module, and the thermal energy warning and control system as described in any one of claims 11-14; The battery module and the thermal energy warning control system are installed in the vehicle body; the thermal energy warning control system is connected to the battery module and is used to provide thermal energy warnings for the battery module and control the safe charging and discharging of the battery module; the vehicle body operates based on the energy provided by the battery module.

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