Battery pressure monitoring and regulation system and method

Abstract

The invention provides a system and a method for monitoring, regulating and controlling the pressure of a battery, which comprehensively considers the suitable pressure range of the battery working under different environment temperatures, battery states and working conditions, and takes the suitable pressure range as the target of battery management and control. By monitoring and analyzing the pressure of each point position and the overall pressure during the operation of the battery, the safety risk and the expected life of the battery are evaluated, and the initial pre-tightening force of the battery and the pressure in the operation process are dynamically adjusted on the basis, so that the battery system can always work in a proper pressure range, and the safety of the battery system is ensured. And long-life and high-safety active regulation and control of the battery system are realized from the aspect of battery force management.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery management and control, and specifically relates to a system and method for controlling a battery for long life and high safety through pressure monitoring and regulation. Background Art

[0002] Lithium-ion batteries produce pressure changes during the charging and discharging process. When they operate within an appropriate pressure range, it is beneficial to improve the battery's dynamic performance, durability and safety. Many existing technologies, such as CN115097338A, CN110828915A, CN215731875U, CN217157440U and other patents, use pressure signals in battery systems to monitor battery life decline, safety degradation, etc., and have made phased progress. However, the use of pressure control methods to extend battery life, early warning and ensure battery safety still needs further research. Therefore, how to accurately monitor and appropriately regulate battery pressure to achieve improved battery performance and life is a technical problem that urgently needs to be solved in this field. Summary of the invention

[0003] In view of this, in order to solve the technical problems existing in this field, the present invention provides a battery pressure monitoring and control system, which is specifically composed of a battery pack, a distributed thin film pressure sensor, a total force sensor, a pressure data acquisition module, a pressure signal analysis module, a life and safety assessment module, a delay circuit, a safety circuit switch, a pressure regulation module, a pressure signal monitoring module and a battery management system;

[0004] Among them, the distributed thin film pressure sensor is attached to the surface of the battery in the battery pack to measure the pressure at different positions of the battery; the total force sensor is used to measure the total pressure value in the battery pack and correct the offset of the measurement result of the distributed thin film pressure sensor;

[0005] The pressure data acquisition module collects data from the distributed thin film pressure sensor and transmits it to the pressure signal analysis module; the pressure signal analysis module analyzes the data and feeds it back to the life and safety evaluation module; the life and safety evaluation module is used to calculate and evaluate the battery aging and safety status, and based on the evaluation results, controls the pressure regulation module to adjust the pressure during the battery operation process, and controls the on and off of the delay circuit and the safety circuit switch to stop the battery pack from supplying power to the outside;

[0006] The distributed thin film pressure sensor, total force sensor and pressure data acquisition module together constitute the system's pressure signal monitoring subsystem; the pressure signal monitoring module, pressure signal analysis module, life and safety assessment module and pressure regulation module together constitute the system's pressure control subsystem; the battery management system is used to control the pressure signal monitoring subsystem and the pressure control subsystem.

[0007] Furthermore, silicone soft pads are attached to both sides of the effective test area of ​​the distributed thin film pressure sensor to ensure the pressure transmission effect between the sensor and the battery surface.

[0008] Furthermore, the pressure signal analysis module obtains the battery initial preload value P0, the battery pack operating total pressure value P, the operating pressure value Pn at each operating point, and the pressure change value △P / △Q corresponding to the unit charge based on the collected pressure data; among which the operating pressure value Pn at each operating point is used to reflect the local pressure change of the battery, and the pressure change value △P / △Q corresponding to the unit charge is used to reflect whether lithium deposition occurs, etc.

[0009] Furthermore, the pressure regulating module specifically adopts an insulating clamping device that can provide clamping pressure to the battery.

[0010] Furthermore, the time delay circuit specifically adopts a time relay, a timer or other circuits composed of elements with a delay function, which are used to realize the time delay function of controlling the battery pack to stop supplying power to the outside.

[0011] Accordingly, the present invention also provides a battery pressure monitoring and control method implemented by the above system, which specifically includes the following steps:

[0012] Step 1. Status acquisition and system initialization: The battery management system acquires various status information including: the time interval △t since the last adjustment of the preload, temperature, rate, SOC, and current aging status, and sets the initial preload range, the total operating pressure range of the battery pack, the total pressure threshold of abnormal operation, the local pressure threshold of abnormal operation, and the pressure change threshold corresponding to the unit charge through the life and safety assessment module;

[0013] Step 2. Initial preload adjustment: compare the time interval △t from the last preload adjustment with the specified time interval. When △t is less than the specified time interval, do not adjust the preload. When △t is greater than the specified time interval, obtain the current initial preload value P0 through the pressure signal analysis module, and compare P0 with the set initial preload range through the life and safety assessment module. When P0 exceeds the set initial preload range, adjust the initial preload of the battery through the pressure regulation module and control it within the set initial preload range. Otherwise, maintain the current initial preload value P0 of the battery.

[0014] Step 3. Battery safety control during battery pack operation: obtain the total operating pressure value P of the battery, the pressure value Pn of each battery point, and the pressure change value △P / △Q corresponding to the unit charge through the pressure signal analysis module; compare the total operating pressure value P with the set abnormal operating total pressure threshold, compare the battery point pressure value Pn with the abnormal operating local pressure threshold, and compare the pressure change value △P / △Q corresponding to the unit charge with the pressure change threshold corresponding to the unit charge through the life and safety assessment module;

[0015] If any of the above pressure signal indicators reaches the corresponding threshold, the life and safety assessment module will determine that the battery pack is in an unsafe state and conduct a safety risk assessment on the battery pack; for the controllable risks after the assessment, the pressure is reduced by the pressure regulation module to achieve safety regulation; when the battery safety regulation is completed, the total operating pressure value P of the battery is continuously adjusted to be within the set threshold range; for uncontrollable risks, the safety warning and battery pack safety protection are triggered, and the battery pack stops supplying power to the outside by controlling the operation of the delay circuit and the on-off of the safety circuit switch;

[0016] Step 4. Battery life extension regulation: When step 3 determines that all pressure signal indicators are lower than the corresponding threshold value, the life and safety assessment module compares the total operating pressure value P with the total operating pressure range set under this state, and feeds the result back to the pressure regulation module; when the total operating pressure value P exceeds the set range, the pressure regulation module adjusts the total operating pressure of the battery and controls it within the set range; otherwise, maintains the current total operating pressure value P of the battery.

[0017] Furthermore, the setting of the total operating pressure range is specifically implemented through the neural network model algorithm running in the battery management system; the algorithm specifically establishes neural network model 1 and neural network model 2; wherein, neural network model 1 is trained using data obtained from cycle experiments under different temperatures, rate conditions, and external pressure conditions of different magnitudes; neural network model 2 is trained using data obtained from cycle experiments under different temperatures, rate conditions, and without external pressure; when the current temperature T, current I, and voltage U of the battery are input, the two optimal external pressure values ​​in the current state of the battery are obtained through neural network model 1 as the upper and lower limits of the external pressure; the curve of the battery operating pressure changing with SOC when no external pressure is applied in the current state of the battery is obtained through neural network model 2; the external pressure value is considered on the basis of the curve of the operating pressure changing with SOC, and finally the set total operating pressure range is obtained.

[0018] The system and method for monitoring and regulating battery pressure provided by the present invention comprehensively consider the appropriate pressure range for battery operation under different ambient temperatures, battery states, and operating conditions, and take it as the target of supervision and control; by monitoring and analyzing the pressure at each point during battery operation and the overall pressure, the safety risk and expected life of the battery are evaluated, and on this basis, the initial preload force of the battery and the pressure during operation are dynamically adjusted, so that the battery system can always operate within an appropriate pressure range, thereby achieving active control of the long life and high safety of the battery system from the perspective of battery force management. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A control schematic diagram of the system provided by the present invention;

[0020] Figure 2 A schematic diagram of the process provided by the present invention;

[0021] Figure 3 This is a schematic diagram of the total operating pressure setting process in the method provided by the present invention;

[0022] Explanation of the accompanying drawings: 1-battery pack, 2-distributed thin film pressure sensor, 3-total force sensor, 4-pressure data acquisition module, 5-pressure signal analysis module, 6-life and safety assessment module, 7-delay circuit, 8-safety circuit switch, 9-pressure regulation module, 10-pressure signal monitoring module, 11-battery management system. DETAILED DESCRIPTION

[0023] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] The present invention provides a battery pressure monitoring and control system, such as Figure 1 As shown, it is specifically composed of a battery pack 1, a distributed thin film pressure sensor 2, a total force sensor 3, a pressure data acquisition module 4, a pressure signal analysis module 5, a life and safety evaluation module 6, a delay circuit 7, a safety circuit switch 8, a pressure regulation module 9, a pressure signal monitoring module 10 and a battery management system 11;

[0025] Among them, the distributed thin film pressure sensor is attached to the surface of the battery in the battery pack to measure the pressure at different positions of the battery; the total force sensor is used to measure the total pressure value in the battery pack and correct the offset of the measurement result of the distributed thin film pressure sensor;

[0026] The pressure data acquisition module collects data from the distributed thin film pressure sensor and transmits it to the pressure signal analysis module; the pressure signal analysis module analyzes the data and feeds it back to the life and safety evaluation module; the life and safety evaluation module is used to calculate and evaluate the battery aging and safety status, and based on the evaluation results, controls the pressure regulation module to adjust the pressure during the battery operation process, and controls the on and off of the delay circuit and the safety circuit switch to stop the battery pack from supplying power to the outside;

[0027] The distributed thin film pressure sensor, total force sensor and pressure data acquisition module together constitute the system's pressure signal monitoring subsystem; the pressure signal monitoring module, pressure signal analysis module, life and safety assessment module and pressure regulation module together constitute the system's pressure control subsystem; the battery management system is used to control the pressure signal monitoring subsystem and the pressure control subsystem.

[0028] In a preferred embodiment of the present invention, silicone rubber pads are respectively attached to both sides of the effective test area of ​​the distributed thin film pressure sensor to ensure the pressure transmission effect between the sensor and the battery surface.

[0029] In a preferred embodiment of the present invention, the pressure signal analysis module obtains the battery initial preload value P0, the battery pack operating total pressure value P, the operating pressure value Pn at each operating point, and the pressure change value △P / △Q corresponding to the unit charge based on the collected pressure data; wherein the operating pressure value Pn at each operating point is used to reflect the local pressure change of the battery, and the pressure change value △P / △Q corresponding to the unit charge is used to reflect whether lithium plating occurs.

[0030] In a preferred embodiment of the present invention, the pressure regulating module specifically adopts an insulating clamping device that can provide clamping pressure to the battery.

[0031] In a preferred embodiment of the present invention, the delay circuit specifically uses a time relay, a timer or other circuits composed of elements with a delay function to achieve a time delay function for controlling the battery pack to stop supplying power to the outside.

[0032] Accordingly, the present invention also provides a battery pressure monitoring and control method implemented by the above system, such as Figure 2 As shown, the specific steps include:

[0033] Step 1. Status acquisition and system initialization: The battery management system acquires various status information including: the time interval △t since the last adjustment of the preload, temperature, rate, SOC, and current aging status, and sets the initial preload range, the total operating pressure range of the battery pack, the total pressure threshold of abnormal operation, the local pressure threshold of abnormal operation, and the pressure change threshold corresponding to the unit charge through the life and safety assessment module;

[0034] Step 2. Initial preload adjustment: compare the time interval △t from the last preload adjustment with the specified time interval. When △t is less than the specified time interval, do not adjust the preload. When △t is greater than the specified time interval, obtain the current initial preload value P0 through the pressure signal analysis module, and compare P0 with the set initial preload range through the life and safety assessment module. When P0 exceeds the set initial preload range, adjust the initial preload of the battery through the pressure regulation module and control it within the set initial preload range. Otherwise, maintain the current initial preload value P0 of the battery.

[0035] Step 3. Battery safety control during battery pack operation: obtain the total operating pressure value P of the battery, the pressure value Pn of each battery point, and the pressure change value △P / △Q corresponding to the unit charge through the pressure signal analysis module; compare the total operating pressure value P with the set abnormal operating total pressure threshold, compare the battery point pressure value Pn with the abnormal operating local pressure threshold, and compare the pressure change value △P / △Q corresponding to the unit charge with the pressure change threshold corresponding to the unit charge through the life and safety assessment module;

[0036] If any of the above pressure signal indicators reaches the corresponding threshold, the life and safety assessment module will determine that the battery pack is in an unsafe state and conduct a safety risk assessment on the battery pack; for the controllable risks after the assessment, the pressure is reduced by the pressure regulation module to achieve safety regulation; when the battery safety regulation is completed, the total operating pressure value P of the battery is continuously adjusted to be within the set threshold range; for uncontrollable risks, the safety warning and battery pack safety protection are triggered, and the battery pack stops supplying power to the outside by controlling the operation of the delay circuit and the on-off of the safety circuit switch;

[0037] Step 4. Battery life extension regulation: When step 3 determines that all pressure signal indicators are lower than the corresponding threshold value, the life and safety assessment module compares the total operating pressure value P with the total operating pressure range set under this state, and feeds the result back to the pressure regulation module; when the total operating pressure value P exceeds the set range, the pressure regulation module adjusts the total operating pressure of the battery and controls it within the set range; otherwise, maintains the current total operating pressure value P of the battery.

[0038] In a preferred embodiment of the present invention, the setting of the operating total pressure range is specifically implemented by a neural network model algorithm running in the battery management system; Figure 3As shown, the algorithm specifically establishes neural network model 1 and neural network model 2; wherein, neural network model 1 is trained using data obtained from cycle experiments under different temperatures, rate conditions, and external pressure conditions of different magnitudes; neural network model 2 is trained using data obtained from cycle experiments under different temperatures, rate conditions, and without external pressure; when the current temperature T, current I, and voltage U of the battery are input, the two optimal external pressure values ​​in the current state of the battery are obtained through neural network model 1 as the upper and lower limits of the external pressure; the curve of the battery operating pressure changing with SOC when no external pressure is applied in the current state of the battery is obtained through neural network model 2; the external pressure value is considered on the basis of the curve of the operating pressure changing with SOC, and finally the set total operating pressure range is obtained.

[0039] In a specific embodiment of the present invention, the initial preload range is set to 0.05MPa-0.2MPa, and the total operating pressure range is set to Figure 3 The method shown determines that the abnormal operating total pressure threshold is 130% of the set total operating pressure under each state (temperature, rate, SOC, aging state), the abnormal operating local pressure threshold is 125% of the maximum value of the set local operating pressure under each state, and the pressure change threshold corresponding to the unit charge is the maximum value of △P / △Q under the non-lithium precipitation charging condition measured in the experiment.

[0040] It should be understood that the size of the serial numbers of the steps in the embodiment of the present invention does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0041] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A battery pressure monitoring and control system, characterized in that: Specifically, it consists of a battery pack, a distributed thin-film pressure sensor, a total force sensor, a pressure data acquisition module, a pressure signal analysis module, a life and safety assessment module, a delay circuit, a safety circuit switch, a pressure regulation module, a pressure signal monitoring module, and a battery management system. Among them, the distributed thin film pressure sensor is attached to the surface of the battery in the battery pack to measure the pressure at different positions of the battery; the total force sensor is used to measure the total pressure value in the battery pack and correct the offset of the measurement result of the distributed thin film pressure sensor; The pressure data acquisition module collects data from the distributed thin film pressure sensor and transmits it to the pressure signal analysis module; the pressure signal analysis module analyzes the data and feeds it back to the life and safety evaluation module; the life and safety evaluation module is used to calculate and evaluate the battery aging and safety status, and based on the evaluation results, controls the pressure regulation module to adjust the pressure during the battery operation process, and controls the on and off of the delay circuit and the safety circuit switch to stop the battery pack from supplying power to the outside; The distributed thin film pressure sensor, total force sensor and pressure data acquisition module together constitute the system's pressure signal monitoring subsystem; the pressure signal monitoring module, pressure signal analysis module, life and safety assessment module and pressure regulation module together constitute the system's pressure control subsystem; the battery management system is used to control the pressure signal monitoring subsystem and the pressure control subsystem.

2. The battery pressure monitoring and control system according to claim 1, characterized in that: Silicone soft pads are attached to both sides of the effective test area of ​​the distributed thin film pressure sensor to ensure the pressure transmission effect between the sensor and the battery surface.

3. The battery pressure monitoring and control system according to claim 1, characterized in that: The pressure signal analysis module obtains the battery initial preload value P0, the battery pack operating total pressure value P, the operating pressure value Pn at each operating point, and the pressure change value △P / △Q corresponding to the unit charge based on the collected pressure data; among which the operating pressure value Pn at each operating point is used to reflect the local pressure change of the battery, and the pressure change value △P / △Q corresponding to the unit charge is used to reflect whether lithium plating occurs.

4. The battery pressure monitoring and control system according to claim 1, characterized in that: The pressure regulating module specifically adopts an insulating clamping device that can provide clamping pressure to the battery.

5. The battery pressure monitoring and control system according to claim 1, characterized in that: The delay circuit specifically uses a time relay, a timer or other circuits composed of elements with a delay function to achieve a time delay function for controlling the battery pack to stop supplying power to the outside.

6. A battery pressure monitoring and control method implemented by the system according to any one of claims 1 to 5, characterized in that: The specific steps include: Step 1. Status acquisition and system initialization: The battery management system acquires various status information including: the time interval △t since the last adjustment of the preload, temperature, rate, SOC, and current aging status, and sets the initial preload range, the total operating pressure range of the battery pack, the total pressure threshold of abnormal operation, the local pressure threshold of abnormal operation, and the pressure change threshold corresponding to the unit charge through the life and safety assessment module; Step 2. Initial preload adjustment: compare the time interval △t from the last preload adjustment with the specified time interval. When △t is less than the specified time interval, do not adjust the preload. When △t is greater than the specified time interval, obtain the current initial preload value P0 through the pressure signal analysis module, and compare P0 with the set initial preload range through the life and safety assessment module. When P0 exceeds the set initial preload range, adjust the initial preload of the battery through the pressure regulation module and control it within the set initial preload range. Otherwise, maintain the current initial preload value P0 of the battery. Step 3. Battery safety control during battery pack operation: obtain the total operating pressure value P of the battery, the pressure value Pn of each battery point, and the pressure change value △P / △Q corresponding to the unit charge through the pressure signal analysis module; compare the total operating pressure value P with the set abnormal operating total pressure threshold, compare the battery point pressure value Pn with the abnormal operating local pressure threshold, and compare the pressure change value △P / △Q corresponding to the unit charge with the pressure change threshold corresponding to the unit charge through the life and safety assessment module; If any of the above pressure signal indicators reaches the corresponding threshold, the life and safety assessment module will determine that the battery pack is in an unsafe state and conduct a safety risk assessment on the battery pack; for the controllable risks after the assessment, the pressure is reduced by the pressure regulation module to achieve safety regulation; when the battery safety regulation is completed, the total operating pressure value P of the battery is continuously adjusted to be within the set threshold range; for uncontrollable risks, the safety warning and battery pack safety protection are triggered, and the battery pack stops supplying power to the outside by controlling the operation of the delay circuit and the on-off of the safety circuit switch; Step 4. Battery life extension regulation: When step 3 determines that any one of the pressure signal indicators reaches the corresponding threshold, the life and safety assessment module compares the total operating pressure value P with the total operating pressure range set under this state, and feeds the result back to the pressure regulation module; when the total operating pressure value P exceeds the set range, the pressure regulation module adjusts the total operating pressure of the battery and controls it within the set range; otherwise, maintains the current total operating pressure value P of the battery.

7. The battery pressure monitoring and control method according to claim 6, characterized in that: The setting of the total operating pressure range is specifically implemented through the neural network model algorithm running in the battery management system; the algorithm specifically establishes neural network model 1 and neural network model 2; wherein, neural network model 1 is trained using data obtained from cycle experiments under different temperatures, rate conditions, and external pressure conditions of different magnitudes; neural network model 2 is trained using data obtained from cycle experiments under different temperatures, rate conditions, and without external pressure; when the current temperature T, current I, and voltage U of the battery are input, the two optimal external pressure values ​​in the current state of the battery are obtained through neural network model 1 as the upper and lower limits of the external pressure; the curve of the battery operating pressure changing with SOC when no external pressure is applied in the current state of the battery is obtained through neural network model 2; the external pressure value is considered on the basis of the curve of the operating pressure changing with SOC, and finally the set total operating pressure range is obtained.

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