An intelligent monitoring system and method based on lithium battery discharge strategy

Abstract

The present invention discloses an intelligent monitoring system and method based on a lithium battery discharge strategy, which specifically relates to the technical field of lithium battery discharge monitoring, including a lithium battery internal resistance monitoring module, a monitoring resource allocation module, a lithium battery discharge process data acquisition module, a discharge risk monitoring module and a discharge strategy management module. By real-time monitoring of the lithium battery internal resistance, internal resistance growth rate, electrical variables and temperature parameters, a health index and a risk index are calculated, and monitoring resource allocation is automatically optimized based on the battery internal resistance development health index to achieve timely risk response and efficient resource utilization; by controlling the lithium battery's over-discharge risk index and discharge loss index, the lithium battery discharge strategy is optimized to reduce safety risks, analyze the discharge strategy execution status, evaluate the failure index, ensure the effective execution of the strategy, and warn or cut off the power supply under abnormal circumstances to ensure the safety of the lithium battery and extend the service life.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium battery discharge monitoring, and more specifically, to an intelligent monitoring system and method based on lithium battery discharge strategy. Background Art

[0002] Lithium battery intelligent monitoring system and lithium battery discharge strategy are important components of lithium battery management. Together, they ensure the safe, efficient and long-life operation of lithium batteries. The lithium battery intelligent monitoring system measures key electrical variables (such as voltage, current, temperature, etc.) by real-time monitoring of the charging and discharging behavior of lithium batteries, and analyzes and evaluates the operating status of lithium batteries based on these electrical variable data. The system aims to prevent safety hazards such as overcharging, over-discharging, and overheating, and improve the efficiency and life of lithium batteries. Based on the operating status data provided by the lithium battery intelligent monitoring system, the discharge strategy aims to optimize the discharge behavior of lithium batteries, improve discharge efficiency and extend battery life. The discharge strategy should be dynamically adjusted according to the current state of the battery (such as SOC, temperature, internal resistance, etc.) and user needs (such as discharge rate, discharge depth, etc.).

[0003] However, it still has many shortcomings in actual use. For example, when processing large amounts of data, the system may be delayed due to insufficient computing power or inefficient algorithms, resulting in an inability to timely understand the current status of the lithium battery, increasing safety risks; the existing discharge strategy management is not intelligent enough, and lacks a solution to monitor the execution status of the discharge strategy and take measures based on the execution status. Summary of the invention

[0004] In order to overcome the above-mentioned defects of the prior art, the present invention provides an intelligent monitoring system and method based on a lithium battery discharge strategy, which allocates monitoring resources for the lithium battery by measuring the internal resistance of the lithium battery and the battery internal resistance development health index, thereby avoiding the inability to timely understand the current status of the lithium battery, and solving the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: an intelligent monitoring system based on lithium battery discharge strategy, comprising:

[0006] The lithium battery internal resistance monitoring module obtains the internal resistance of the lithium battery by averaging several tests; the internal resistance growth rate of the lithium battery is expressed based on the ratio of the internal resistance growth of the lithium battery and the cumulative use time of the lithium battery; the internal resistance value is recorded as CR and the internal resistance growth rate is recorded as Rv;

[0007] The monitoring resource allocation module calculates the battery internal resistance development health index based on the internal resistance and internal resistance growth rate of the lithium battery; and allocates the monitoring resources of the lithium battery based on the battery internal resistance development health index;

[0008] The lithium battery discharge process data acquisition module is used to measure the electrical variables and temperature parameters of the lithium battery during the discharge process, and transmit the measured data to the discharge risk analysis module; the electrical variables are measured by setting monitoring points in the lithium battery, and the electrical variables include the remaining power of the lithium battery, the real-time discharge rate, the power loss and the effective discharge amount;

[0009] The discharge risk monitoring module is used to analyze the electrical variables and temperature parameters of the lithium battery during the discharge process to obtain the over-discharge risk index ODR and the discharge loss index DLI; and transmit the monitoring results to the discharge strategy management module;

[0010] The discharge strategy management module is used to compare the acquired over-discharge risk index ODR and discharge loss index DLI of the lithium battery with the corresponding preset values, and take measures according to the comparison results to ensure that the over-discharge risk index ODR and discharge loss index DLI do not exceed the preset values.

[0011] Preferably, the lithium battery internal resistance monitoring module starts testing from a fully charged lithium battery state by using a hybrid pulse power characteristic testing method, performs m tests, obtains instantaneous voltage, calculates the internal resistance by using Ohm's law to obtain the internal resistance of the lithium battery, and obtains the internal resistance of the lithium battery by taking the average value of the m tests. The testing process of the lithium battery internal resistance includes the following steps:

[0012] Step S11, discharging and standing:

[0013] Ensure that the lithium battery is fully charged and connect the test equipment, which includes a voltage sensor, a current sensor and a data recording system; start from the fully charged state and discharge with an appropriate current to the predetermined discharge depth; after the discharge is completed, let the lithium battery stand for 1 hour to ensure that the thermal and electrochemical balance is achieved inside the lithium battery;

[0014] Step S12: Pulse test:

[0015] After the rest period is over, a short pulse current is applied to the lithium battery, where the short pulse current is 1C or less of the rated capacity of the battery, and the instantaneous voltage change before and after the pulse starts is recorded;

[0016] Step S13, repeat the test: repeat the above-mentioned discharge, static and pulse test processes, each time the discharge depth gradient increases until a predetermined discharge depth (such as DOD = 10%, 20%, ..., 100%) is reached, and at each discharge depth, a pulse test is performed and data is recorded;

[0017] Step S14: Data recording:

[0018] For each pulse test, record the voltage drop caused by the pulse, and use Ohm's law or an equivalent circuit model to calculate the internal resistance; calculate the average value of the internal resistance at all test depths to obtain the average internal resistance of the lithium battery.

[0019] Preferably, the process of obtaining the battery internal resistance development health index H satisfies the following formula:

[0020]

[0021] Among them, k is a constant used to adjust the numerical range of the health index.

[0022] Preferably, the over-discharge risk index ODR is obtained in the following manner:

[0023] The remaining power of the lithium battery and the total capacity of the lithium battery are measured and recorded as Q re and Q to ; The minimum safe level of remaining power Q is obtained through experiments sa ;

[0024] Based on the measured remaining capacity of the lithium battery, the maximum discharge rate and the real-time discharge rate of the lithium battery, the fastest discharge time and the predicted discharge time of the lithium battery are calculated, and the fastest discharge time and the predicted discharge time are recorded as T fa and T pr ;

[0025] By formula The over-discharge risk index ODR is calculated;

[0026] Among them, T th It represents the set time threshold, indicating the time it takes for the lithium battery power to drop below the safe level, which is unacceptable. wr represents the impact of ambient temperature on the discharge coefficient. α represents the impact index of the remaining power of the lithium battery, which is used to adjust the relative importance of the remaining power of the lithium battery. β represents the impact index of the predicted discharge time of the lithium battery, which is used to adjust the relative importance of the discharge rate.

[0027] Preferably, the ambient temperature influence discharge coefficient wr is obtained in the following manner:

[0028] Get the lowest temperature of the lithium battery, the temperature when the lithium battery has the best performance, and the real-time temperature of the lithium battery, which are recorded as W min , W opt and W n ; Through the formula The ambient temperature influence coefficient is calculated; where γ represents the temperature influence index, which is used to adjust the relative importance of the temperature factor in the over-discharge risk index; the influence of ambient temperature on battery performance is taken into account; the expression in brackets is actually a normalized temperature deviation, which calculates the relative distance between the current temperature and the optimal temperature, and realizes the reverse processing through 1-, so that when the temperature is close to the optimal, the value is close to 1, and when the temperature deviates from the optimal, the value decreases.

[0029] Preferably, the discharge loss index DLI is obtained as follows:

[0030] By formula The discharge loss index is calculated, where EL represents the amount of power loss, EDE represents the effective discharge amount, Eff represents the energy efficiency transfer efficiency, and δ represents the temperature influence coefficient, which indicates the increase in discharge loss when the temperature deviates from the optimal value by one unit.

[0031] The discharge loss index measures the ratio of the amount of electricity lost during the discharge process to the effective discharge amount, and takes into account the additional effects of energy transfer efficiency and temperature on the discharge loss.

[0032] Preferably, when the over-discharge risk index and the discharge loss index exceed the corresponding preset values, a corresponding discharge control instruction is generated; the over-discharge risk index and the discharge loss index are kept within a preset range by executing the discharge control instruction; when the ODR approaches or exceeds the preset value, measures taken include reducing the discharge rate, suspending the discharge, or starting the cooling system to lower the temperature; when the DLI approaches or exceeds the preset value, unnecessary power loss is reduced by adjusting the load, optimizing the discharge process, or starting the cooling system to lower the temperature.

[0033] Preferably, the intelligent monitoring system based on lithium battery discharge strategy also includes:

[0034] The discharge strategy monitoring module is used to monitor the discharge strategy execution status and analyze the discharge strategy execution failure index;

[0035] Based on the discharge strategy execution failure index, corresponding measures are taken, including: triggering the alarm system or automatically cutting off the power supply; replacing and maintaining the lithium battery.

[0036] Preferably, the discharge strategy execution failure index Fcz is obtained in the following manner:

[0037] Obtaining the real-time over-discharge risk index and the real-time discharge loss index of the lithium battery, and obtaining the corresponding thresholds of the over-discharge risk index and the discharge loss index;

[0038] The discharge data of the lithium battery is measured and divided into n time zones, where i represents the number of the time zone.

[0039] The over-discharge risk index and discharge loss index of each region are obtained, and the over-discharge risk index and discharge loss index of the i-th time region are recorded as ODR_i and DLI_i; the internal resistance growth rate of each region is obtained, recorded as Rv_i; through the following formula,

[0040] The discharge strategy execution failure index is calculated, where Yo and Yd represent the corresponding thresholds of the over-discharge risk index and the discharge loss index, respectively.

[0041] To achieve the above object, the present invention provides the following technical solution: an intelligent monitoring method based on lithium battery discharge strategy, comprising the following steps:

[0042] Step 1: averaging the internal resistance of the lithium battery through several tests; the internal resistance growth rate of the lithium battery is expressed based on the ratio of the internal resistance growth of the lithium battery and the cumulative use time of the lithium battery;

[0043] Step 2: Based on the internal resistance and internal resistance growth rate of the lithium battery, calculate the battery internal resistance development health index; allocate lithium battery monitoring resources based on the battery internal resistance development health index;

[0044] Step 3: Measure the electrical variables and temperature parameters of the lithium battery during the discharge process;

[0045] Step 4: Analyze the electrical variables and temperature parameters of the lithium battery during the discharge process to obtain the over-discharge risk index ODR and the discharge loss index DLI;

[0046] Step 5: Compare the obtained over-discharge risk index ODR and discharge loss index DLI of the lithium battery with the corresponding preset values; set reasonable ODR and DLI preset values ​​according to battery specifications, usage scenarios and safety standards; take measures according to the comparison results to ensure that the over-discharge risk index ODR and discharge loss index DLI do not exceed the preset values;

[0047] Step 6: Monitor the execution status of the discharge strategy and analyze the failure index of the discharge strategy execution; based on the failure index of the discharge strategy execution and the corresponding threshold Y F Take corresponding measures.

[0048] Technical effects and advantages of the present invention:

[0049] (1) The intelligent monitoring system based on the lithium battery discharge strategy provided by the present invention obtains the internal resistance and internal resistance growth rate of the lithium battery by measurement, and obtains the battery internal resistance development health index based on the internal resistance and internal resistance growth rate of the lithium battery; allocates lithium battery monitoring resources based on the battery internal resistance development health index, and automatically adjusts the monitoring resource allocation based on data analysis, thereby achieving optimal configuration and efficient utilization of resources, solving the problem that the existing system is unable to analyze and respond to risky lithium batteries in a timely manner, and reducing safety risks.

[0050] (2) The intelligent monitoring system based on the lithium battery discharge strategy provided by the present invention obtains the over-discharge risk index ODR and the discharge loss index DLI by analyzing the electrical variables and temperature parameters of the lithium battery during the discharge process; and is used to compare the obtained over-discharge risk index ODR and the discharge loss index DLI of the lithium battery with the corresponding preset values, and take measures according to the comparison results to ensure that the over-discharge risk index ODR and the discharge loss index DLI do not exceed the preset values, thereby achieving a comprehensive assessment of the health status of the lithium battery and a timely warning of risks, and realizing the discharge strategy design of the lithium battery, thereby reducing safety risks and extending the service life of the lithium battery.

[0051] (3) The intelligent monitoring system based on the lithium battery discharge strategy provided by the present invention monitors the discharge strategy execution status and analyzes the discharge strategy execution failure index; based on the discharge strategy execution failure index and the corresponding threshold value Y F By taking corresponding measures, abnormal lithium batteries can be effectively screened. When the lithium battery discharge strategy is poorly executed, the alarm system will be triggered or the power will be automatically cut off to prompt replacement and maintenance of the lithium battery, thus avoiding losses caused by lithium battery failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 This is a structural block diagram of the intelligent monitoring system based on the lithium battery discharge strategy of the present invention.

[0053] Figure 2 It is a structural block diagram of the intelligent monitoring system based on the discharge strategy monitoring module of the present invention. DETAILED DESCRIPTION

[0054] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0055] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0056] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present application, its application, or uses.

[0057] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0058] Example 1

[0059] See also Figure 1 The present invention provides a block diagram of an intelligent monitoring system based on a lithium battery discharge strategy. Figure 1 An intelligent monitoring system based on a lithium battery discharge strategy is shown, comprising:

[0060] The lithium battery internal resistance monitoring module obtains the internal resistance of the lithium battery by averaging several tests; the internal resistance growth rate of the lithium battery is expressed based on the ratio of the internal resistance growth of the lithium battery and the cumulative use time of the lithium battery; the internal resistance value is recorded as CR and the internal resistance growth rate is recorded as Rv;

[0061] The monitoring resource allocation module calculates the battery internal resistance development health index based on the internal resistance and internal resistance growth rate of the lithium battery; and allocates the monitoring resources of the lithium battery based on the battery internal resistance development health index;

[0062] The lithium battery discharge process data acquisition module is used to measure the electrical variables and temperature parameters of the lithium battery during the discharge process, and transmit the measured data to the discharge risk analysis module; the electrical variables are measured by setting monitoring points in the lithium battery, and the electrical variables include the remaining power of the lithium battery, the real-time discharge rate, the power loss and the effective discharge amount;

[0063] The discharge risk monitoring module is used to analyze the electrical variables and temperature parameters of the lithium battery during the discharge process to obtain the over-discharge risk index ODR and the discharge loss index DLI; and transmit the monitoring results to the discharge strategy management module;

[0064] The discharge strategy management module is used to compare the acquired over-discharge risk index ODR and discharge loss index DLI of the lithium battery with the corresponding preset values, and take measures according to the comparison results to ensure that the over-discharge risk index ODR and discharge loss index DLI do not exceed the preset values.

[0065] It needs to be further explained in the embodiment of the present invention that the lithium battery internal resistance monitoring module starts testing from the fully charged state of the lithium battery through a mixed pulse power characteristic testing method, performs n tests, obtains the instantaneous voltage, calculates the internal resistance through Ohm's law or an equivalent circuit model to obtain the internal resistance of the lithium battery, and obtains the internal resistance of the lithium battery by taking the average value of n tests; the testing process of the lithium battery internal resistance includes the following steps:

[0066] Step S11, discharging and standing:

[0067] Ensure that the lithium battery is fully charged and connect the test equipment, which includes a voltage sensor, a current sensor and a data recording system; start from the fully charged state and discharge with an appropriate current to the predetermined discharge depth; after the discharge is completed, let the lithium battery stand for 1 hour to ensure that the thermal and electrochemical balance is achieved inside the lithium battery;

[0068] Step S12: Pulse test:

[0069] After the rest period is over, a short pulse current is applied to the lithium battery, where the short pulse current is 1C or less of the rated capacity of the battery, and the instantaneous voltage change before and after the pulse starts is recorded;

[0070] Step S13, repeat the test: repeat the above-mentioned discharge, static and pulse test processes, each time the discharge depth gradient increases until a predetermined discharge depth (such as DOD = 10%, 20%, ..., 100%) is reached, and at each discharge depth, a pulse test is performed and data is recorded;

[0071] Step S14: Data recording:

[0072] For each pulse test, record the voltage drop caused by the pulse, and use Ohm's law or an equivalent circuit model to calculate the internal resistance; calculate the average value of the internal resistance at all test depths to obtain the average internal resistance of the lithium battery.

[0073] It needs to be further explained in the embodiment of the present invention that the process of obtaining the battery internal resistance development health index H satisfies the following formula:

[0074]

[0075] Among them, k is a constant used to adjust the numerical range of the health index; it comprehensively considers the influence of the current internal resistance value R and the internal resistance growth rate Rv (reflected by ΔR and T) on the battery health status.

[0076] What needs to be further explained in the embodiment of the present invention is that in the lithium battery discharge process data acquisition module, monitoring points are set inside or around the lithium battery through sensors to capture sensor data of electrical variables and temperature parameters in real time. After the sensor data is converted from analog to digital, it is processed and transmitted by a microcontroller or a data acquisition card.

[0077] It needs to be further explained in the embodiment of the present invention that the over-discharge risk index ODR is obtained in the following manner:

[0078] The remaining power of the lithium battery and the total capacity of the lithium battery are measured and recorded as Q re and Q to ; The minimum safe level of remaining power Q is obtained through experiments sa ;

[0079] Based on the measured remaining capacity of the lithium battery, the maximum discharge rate and the real-time discharge rate of the lithium battery, the fastest discharge time and the predicted discharge time of the lithium battery are calculated, and the fastest discharge time and the predicted discharge time are recorded as T fa and T pr ;

[0080] By formula The over-discharge risk index ODR is calculated;

[0081] Among them, T th It represents the set time threshold, indicating the time it takes for the lithium battery power to drop below the safe level, which is unacceptable. wr represents the impact of ambient temperature on the discharge coefficient. α represents the impact index of the remaining power of the lithium battery, which is used to adjust the relative importance of the remaining power of the lithium battery. β represents the impact index of the predicted discharge time of the lithium battery, which is used to adjust the relative importance of the discharge rate.

[0082] It needs to be further explained in the embodiment of the present invention that the ambient temperature affects the discharge coefficient wr in the following manner:

[0083] Get the lowest temperature of the lithium battery, the temperature when the lithium battery has the best performance, and the real-time temperature of the lithium battery, which are recorded as W min , W opt and W n ; Through the formula The ambient temperature influence coefficient is calculated; where γ represents the temperature influence index, which is used to adjust the relative importance of the temperature factor in the over-discharge risk index; the influence of ambient temperature on battery performance is taken into account; the expression in brackets is actually a normalized temperature deviation, which calculates the relative distance between the current temperature and the optimal temperature, and realizes the reverse processing through 1-, so that when the temperature is close to the optimal, the value is close to 1, and when the temperature deviates from the optimal, the value decreases.

[0084] It needs to be further explained in the embodiment of the present invention that the discharge loss index DLI is obtained in the following manner:

[0085] By formula The discharge loss index is calculated, where EL represents the amount of power loss, EDE represents the effective discharge amount, Eff represents the energy efficiency transmission efficiency, δ represents the temperature influence coefficient, and represents the increase in discharge loss when the temperature deviates from the optimal value by one unit; represents the current temperature W n With the optimal working temperature W opt The absolute difference between the two; when the temperature is equal to the optimal operating temperature, the factor is 1, indicating that there is no additional temperature influence; when the temperature deviates from the optimal value, the factor will be greater than 1, indicating that the discharge loss increases due to temperature deviation;

[0086] The discharge loss index measures the ratio of the amount of electricity lost during the discharge process to the effective discharge amount, and takes into account the additional effects of energy transfer efficiency and temperature on the discharge loss.

[0087] What needs to be further explained in the embodiments of the present invention is that when the over-discharge risk index and the discharge loss index exceed the corresponding preset values, a corresponding discharge control instruction is generated; the over-discharge risk index and the discharge loss index are made within a preset range by executing the discharge control instruction; when the ODR approaches or exceeds the preset value, the measures taken include reducing the discharge rate, suspending the discharge, or starting the cooling system to lower the temperature; when the DLI approaches or exceeds the preset value, the unnecessary power loss is reduced by adjusting the load, optimizing the discharge process, or starting the cooling system to lower the temperature.

[0088] Summary: The embodiment of the present invention obtains the internal resistance and internal resistance growth rate of the lithium battery by measurement, and obtains the battery internal resistance development health index based on the internal resistance and internal resistance growth rate of the lithium battery; allocates monitoring resources for the lithium battery based on the battery internal resistance development health index, and automatically adjusts the monitoring resource allocation based on data analysis to achieve optimal configuration and efficient utilization of resources, solves the problem that the system cannot promptly analyze and respond to risky lithium batteries, and reduces safety risks; obtains the over-discharge risk index ODR and the discharge loss index DLI by analyzing the electrical variables and temperature parameters of the lithium battery during the discharge process; compares the obtained over-discharge risk index ODR and discharge loss index DLI of the lithium battery with the corresponding preset values, and takes measures according to the comparison results to ensure that the over-discharge risk index ODR and the discharge loss index DLI do not exceed the preset values, so as to achieve a comprehensive assessment of the health status of the lithium battery and timely warning of risks, and realize the discharge strategy design of the lithium battery, thereby reducing safety risks and extending the service life of the lithium battery.

[0089] Example 2

[0090] See also Figure 2The structure block diagram of the intelligent monitoring system based on the discharge strategy monitoring module of the embodiment of the present invention is different from the embodiment 1 in that the intelligent monitoring system based on the lithium battery discharge strategy further includes:

[0091] The discharge strategy monitoring module is used to monitor the discharge strategy execution status and analyze the discharge strategy execution failure index; based on the discharge strategy execution failure index and the corresponding threshold Y F Take corresponding measures.

[0092] What needs to be further explained in the embodiment of the present invention is the method of obtaining the failure index Fcz of the discharge strategy execution:

[0093] Obtaining the real-time over-discharge risk index and the real-time discharge loss index of the lithium battery, and obtaining the corresponding thresholds of the over-discharge risk index and the discharge loss index;

[0094] The discharge data of the lithium battery is measured and divided into n time zones, where i represents the number of the time zone.

[0095] The over-discharge risk index and discharge loss index of each region are obtained, and the over-discharge risk index and discharge loss index of the i-th time region are recorded as ODR_i and DLI_i; the internal resistance growth rate of each region is obtained, recorded as Rv_i

[0096] Through the following formula,

[0097] The discharge strategy execution failure index is calculated, where Yo and Yd represent the corresponding thresholds of the over-discharge risk index and the discharge loss index, respectively. The larger the discharge strategy execution failure index value, the worse the discharge strategy execution effect.

[0098] When the discharge strategy execution failure index does not exceed the corresponding threshold Y F , indicating that the discharge strategy is executed normally and no measures are taken; when the discharge strategy execution failure index exceeds the corresponding threshold Y F , indicating that the discharge strategy is poorly executed, triggering the alarm system or automatically cutting off the power supply, prompting the replacement and maintenance of the lithium battery.

[0099] It needs to be further explained in the embodiment of the present invention that the embodiment of the present invention provides an intelligent monitoring method based on a lithium battery discharge strategy, comprising the following steps:

[0100] Step 1: averaging the internal resistance of the lithium battery through several tests; the internal resistance growth rate of the lithium battery is expressed based on the ratio of the internal resistance growth of the lithium battery and the cumulative use time of the lithium battery;

[0101] Step 2: Based on the internal resistance and internal resistance growth rate of the lithium battery, calculate the battery internal resistance development health index; allocate lithium battery monitoring resources based on the battery internal resistance development health index;

[0102] Step 3: Measure the electrical variables and temperature parameters of the lithium battery during the discharge process;

[0103] Step 4: Analyze the electrical variables and temperature parameters of the lithium battery during the discharge process to obtain the over-discharge risk index ODR and the discharge loss index DLI;

[0104] Step 5: Compare the obtained over-discharge risk index ODR and discharge loss index DLI of the lithium battery with the corresponding preset values; set reasonable ODR and DLI preset values ​​according to battery specifications, usage scenarios and safety standards; take measures according to the comparison results to ensure that the over-discharge risk index ODR and discharge loss index DLI do not exceed the preset values;

[0105] Step 6: Monitor the execution status of the discharge strategy and analyze the failure index of the discharge strategy execution; based on the failure index of the discharge strategy execution and the corresponding threshold Y F Take corresponding measures.

[0106] In summary, the embodiment of the present invention monitors the discharge strategy execution status and analyzes the discharge strategy execution failure index; based on the discharge strategy execution failure index and the corresponding threshold value Y F By taking corresponding measures, abnormal lithium batteries can be effectively screened. When the lithium battery discharge strategy is poorly executed, the alarm system will be triggered or the power will be automatically cut off to prompt replacement and maintenance of the lithium battery, thus avoiding losses caused by lithium battery failure.

[0107] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An intelligent monitoring system based on lithium battery discharge strategy, characterized in that: include: The lithium battery internal resistance monitoring module obtains the internal resistance of the lithium battery by averaging several tests; The internal resistance growth rate of the lithium battery is expressed based on the ratio of the internal resistance growth of the lithium battery and the cumulative use time of the lithium battery; the internal resistance value is recorded as CR and the internal resistance growth rate is recorded as Rv; The monitoring resource allocation module calculates the battery internal resistance development health index based on the internal resistance and internal resistance growth rate of the lithium battery, and allocates the monitoring resources of the lithium battery based on the battery internal resistance development health index; The lithium battery discharge process data acquisition module is used to measure the electrical variables and temperature parameters of the lithium battery during the discharge process, and transmit the measured data to the discharge risk monitoring module; The discharge risk monitoring module is used to analyze the electrical variables and temperature parameters of the lithium battery during the discharge process to obtain the over-discharge risk index ODR and the discharge loss index DLI; and transmit the monitoring results to the discharge strategy management module; The over-discharge risk index ODR is obtained as follows: The remaining power of the lithium battery and the total capacity of the lithium battery are measured and recorded as Q re and Q to ; The minimum safe level of remaining power Q is obtained through experiments sa ; Based on the measured remaining capacity of the lithium battery, the maximum discharge rate and the real-time discharge rate of the lithium battery, the fastest discharge time and the predicted discharge time of the lithium battery are calculated, and the fastest discharge time and the predicted discharge time are recorded as T fa and T pr ; By formula The over-discharge risk index ODR is calculated; Among them, T th It indicates the set time threshold, indicating the time within which the lithium battery power drops below the safe level and is unacceptable; wr indicates the discharge coefficient affected by the ambient temperature; α indicates the influence index of the remaining power of the lithium battery, which is used to adjust the relative importance of the remaining power of the lithium battery; β indicates the influence index of the predicted discharge time of the lithium battery, which is used to adjust the relative importance of the discharge rate; the method for obtaining the discharge coefficient affected by the ambient temperature wr is: obtaining the lowest temperature of the lithium battery, the temperature when the lithium battery performance is optimal, and the real-time temperature of the lithium battery, which are respectively recorded as W min , W opt and W n ; Through the formula The ambient temperature influence coefficient is calculated; wherein γ represents the temperature influence index, which is used to adjust the relative importance of the temperature factor in the over-discharge risk index; The discharge loss index DLI is obtained as follows: By formula The discharge loss index is calculated, where EL represents the amount of power loss, EDE represents the effective discharge amount, Eff represents the energy efficiency transfer efficiency, and δ represents the temperature influence coefficient, which indicates the increase in discharge loss when the temperature deviates from the optimal value by one unit. The discharge strategy management module is used to compare the acquired over-discharge risk index ODR and discharge loss index DLI of the lithium battery with the corresponding preset values, and take measures according to the comparison results to ensure that the over-discharge risk index ODR and discharge loss index DLI do not exceed the preset values.

2. The intelligent monitoring system based on lithium battery discharge strategy according to claim 1, characterized in that: The lithium battery internal resistance monitoring module uses a mixed pulse power characteristic testing method to start testing from a fully charged lithium battery state, performs m tests, obtains the instantaneous voltage, calculates the internal resistance using Ohm's law to obtain the internal resistance of the lithium battery, and obtains the internal resistance of the lithium battery by taking the average value of the m tests.

3. The intelligent monitoring system based on lithium battery discharge strategy according to claim 1 is characterized in that: The process of obtaining the battery internal resistance development health index H satisfies the following formula: Among them, k is a constant used to adjust the numerical range of the health index.

4. The intelligent monitoring system based on lithium battery discharge strategy according to claim 1, characterized in that: When the over-discharge risk index and the discharge loss index exceed the corresponding preset values, the corresponding discharge control instructions are generated; the over-discharge risk index and the discharge loss index are kept within the preset range by executing the discharge control instructions; when the ODR exceeds the preset value, the measures taken include reducing the discharge rate, suspending discharge or starting the cooling system to lower the temperature; when the DLI exceeds the preset value, unnecessary power loss is reduced by adjusting the load, optimizing the discharge process or starting the cooling system to lower the temperature.

5. The intelligent monitoring system based on lithium battery discharge strategy according to claim 1, characterized in that: The intelligent monitoring system based on lithium battery discharge strategy also includes: The discharge strategy monitoring module is used to monitor the discharge strategy execution status and analyze the discharge strategy execution failure index; Based on the discharge strategy execution failure index, corresponding measures are taken, including: triggering the alarm system or automatically cutting off the power supply, replacing and maintaining the lithium battery.

6. The intelligent monitoring system based on lithium battery discharge strategy according to claim 5, characterized in that: The method for obtaining the failure index Fcz of the discharge strategy is as follows: Obtaining the real-time over-discharge risk index and the real-time discharge loss index of the lithium battery, and obtaining the corresponding thresholds of the over-discharge risk index and the discharge loss index; The discharge data of the lithium battery is measured and divided into n time zones, where i represents the number of the time zone. The over-discharge risk index and discharge loss index of each region are obtained, and the over-discharge risk index and discharge loss index of the i-th time region are recorded as ODR_i and DLI_i; the internal resistance growth rate of each region is obtained, recorded as Rv_i; through the following formula, The discharge strategy execution failure index is calculated, where Yo and Yd represent the corresponding thresholds of the over-discharge risk index and the discharge loss index, respectively.

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