Storage battery on-line monitoring and intelligent capacity checking device

Abstract

The invention discloses an online monitoring and intelligent capacity checking device for a storage battery, relates to the technical field of intelligent capacity checking, and is used for solving the problems of inaccurate battery management, poor adaptability, non-fine attenuation process and the like in the prior art. Compared with the prior art, three-stage correction is simplified into two-stage correction, consideration of main influence factors is reserved, the calculation process is simplified, and for some conditions with low precision requirements, the first-stage correction and the second-stage correction can still conduct reasonable adjustment on the final voltage under the condition that calculation complexity is not excessively increased. Data of a built-in sensor and historical use data of a battery are fully utilized, so that a correction decision has a basis, the reliability and the accuracy of the whole system are improved, different functions are selected according to actual conditions, voltage attenuation processing in the whole online capacity checking process is optimized, and the reliability and the reliability of the system are improved while the accuracy is ensured. And the overall performance and efficiency of the system are improved.

Description

Technical Field

[0001] The present invention relates to the field of intelligent core capacity technology, and more specifically, to a battery online monitoring and intelligent core capacity device. Background Art

[0002] With the continuous growth of energy demand and the reliance of power systems on energy storage devices, batteries, especially large-scale energy storage batteries, are becoming more and more widely used in power systems. The emergence of online monitoring and intelligent capacity verification technology for batteries aims to grasp the health status, capacity decay and service life of batteries in real time, thereby improving the reliability and economy of the system. The performance of batteries is affected by many factors, including battery type, operating environment, charging and discharging conditions, temperature, humidity and battery aging. Therefore, real-time monitoring of batteries becomes crucial.

[0003] The prior art has the following deficiencies: The battery management system in the prior art may have an inaccurate setting of the termination voltage, resulting in over-discharge or over-charging of the battery, affecting the battery life and safety. Through real-time monitoring of the built-in temperature sensor and discharge current, combined with online capacity verification, it is possible to dynamically determine whether the original termination voltage of the battery is reasonable. The traditional battery discharge process may use a fixed attenuation function, but in practice the discharge characteristics of the battery are often nonlinear. The battery management in the prior art has problems such as insufficient precision, poor adaptability, and imprecise attenuation process.

[0004] In view of the above problems, the present invention proposes a solution. Summary of the invention

[0005] In order to overcome the above-mentioned defects of the prior art, the embodiments of the present invention provide a battery online monitoring and intelligent capacity verification device to solve the problems raised in the above-mentioned background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions: The battery online monitoring and intelligent capacity verification device includes: a correction classification module, a judgment correction module, a selection function module and an attenuation processing module. The signal connection between each module is as follows: Correction classification module: Add PTC resistance load as load correction, combine aging correction and temperature compensation to correct the original termination voltage of the battery as three-level correction, simplify the three-level correction as first-level correction and second-level correction; Judgment and correction module: obtains the temperature data of the built-in temperature sensor and the discharge current to judge whether the original termination voltage of the online core capacity is reasonable. If it is unreasonable, three-level correction is used. If it is reasonable, the correction level is comprehensively judged based on the consistency of the battery's charging state and the capacity attenuation, and the original termination voltage is corrected to the corrected termination voltage. Selected function module: Combine the accuracy requirements of the discharge process and whether the original termination voltage is reasonable to determine whether to select an exponential decay function or a linear decay function as the selected decay function; Attenuation processing module: Use the selected attenuation function and correct termination voltage to process the voltage attenuation process of the online core capacitor.

[0007] In a preferred embodiment, the modified classification module includes the following contents: Load correction: Add a PTC resistor load for correction, select a PTC resistor with appropriate rated power and initial resistance value, connect the PTC resistor in series in the battery discharge circuit, and record the PTC resistor as , let the discharge current of the battery be I, and the load correction of the PTC resistor be expressed as: =I× , where I is the discharge current of the battery, is the PTC resistor; Temperature compensation correction: record the working environment temperature of the battery measured by the temperature sensor as T, obtain the temperature-voltage characteristic curve of the battery, and obtain the current standard temperature based on the curve , then the temperature deviation , the temperature compensation correction is expressed as: , where α is determined by different types of batteries; Aging correction: record the number of battery charge and discharge cycles as n, and record the voltage correction value corresponding to each x% increase in internal resistance. , the internal resistance increases by z% every y cycles, and the internal resistance increase ratio p=ny×z%. The voltage correction value caused by the internal resistance increase is expressed as: =p× , assuming that the increase in internal resistance is ΔR, the relationship coefficient k between the increase in internal resistance and the voltage correction value is determined according to the aging model of different types of batteries. The voltage correction value caused by the increase in internal resistance is expressed as: =k×ΔR, the final aging correction value is expressed as: + ; The original termination voltage is , the temperature compensation correction value calculated above is , aging correction value and PTC resistor load correction value Add together to get the corrected termination voltage ; The importance of the three correction measures is ranked as follows: temperature compensation > aging correction > PTC resistor load. Adding PTC resistor load as load correction, combining aging correction and temperature compensation to correct the original termination voltage of the battery as the third-level correction. According to the importance of the three correction measures, only aging correction and temperature compensation are used to correct the original termination voltage of the battery as the second-level correction. The corrected termination voltage is expressed as: , only use temperature compensation to correct the original termination voltage of the battery as the first-level correction, and the corrected termination voltage is expressed as: .

[0008] In a preferred embodiment, the judgment and correction module includes the following contents: Record the working environment temperature of the battery measured by the temperature sensor as T, record the discharge current of the battery as I, establish the relationship model of temperature-discharge current-termination voltage, substitute the obtained temperature T and discharge current I into the reference model, and calculate the theoretically reasonable termination voltage range arrive , and obtain the actual termination voltage of the current online core capacity process ,when or When the original termination voltage is judged to be unreasonable, a three-level correction is required. When the original termination voltage is judged to be reasonable, the correction level is further judged; Check the consistency of charging status: obtain the battery charging history and count the number of times the charging voltage exceeds the target charging voltage in the recent charging cycle. and the number of times the target charging voltage falls below the lower limit ,when + =0, the charging state consistency is considered good; when + ≤2, the charging state is considered to be relatively consistent; if + >2, the charging status is considered inconsistent.

[0009] Assume the total number of charging cycles is N, when + =0, S=0; when + ≤2, S= ×0.5; when + >2, S= (The value range of S is 0-1); Judgment of capacity attenuation: Based on the rated capacity of the battery and the actual capacity Q measured recently to calculate the capacity retention rate C = , when C ≥ 90%, it is defined as mild attenuation; when 80% ≤ C < 90%, it is defined as moderate attenuation; if C < 80%, it is defined as severe attenuation; When C ≥ 90%, D = 0; when 80% ≤ C < 90%, D = (90% − C) × 10; when C < 80%, D = (90% − C) × 20, (the value range of D is 0 − 20); Combined with the battery's charge state consistency and capacity attenuation, the correction level is comprehensively determined: 1. Level 1 correction: When S=0 and D=0, only temperature compensation correction is required, and the correction level is level 1; 2. Level 2 correction: When S<=0.3 and D<=10, in addition to temperature compensation, the capacity attenuation is taken into account for correction, and the correction level is level 2; 3. Level 3 correction: When S>0.3 or D>10, the correction is made by comprehensively considering the charging state, capacity attenuation and temperature compensation, and the correction level is level 3.

[0010] In a preferred embodiment, the selected function module includes the following contents: Obtain the historical operation data of the battery system that has been put into use, analyze the historical data, obtain the accuracy requirements of the discharge process, and set the threshold to determine the accuracy requirements of the discharge process; After the selected function module receives the accuracy requirement of the discharge process and whether the original termination voltage is reasonable, the accuracy requirement of the discharge process and whether the original termination voltage is reasonable are defined as input variables, and they are divided into different fuzzy sets respectively; Define the selected decay function as the output variable and partition it into fuzzy sets; Formulate fuzzy rules to describe the accuracy requirements of the discharge process and the influence of the reasonable definition of the original termination voltage on the selected decay function; Fuzzy reasoning is performed according to fuzzy rules to determine the selected attenuation function.

[0011] In a preferred embodiment, the attenuation processing module includes the following contents: The exponential decay function is expressed as: ,in: is the voltage at time t, is the initial voltage, τ is the time constant, e is the base of the natural logarithm, and the voltage is set to decrease from the initial value according to the exponential decay function. Exponential decay is performed. When the correction termination voltage is reached, the system stops discharging in time and monitors the voltage in real time. and compare it with the corrected termination voltage. Once the monitored voltage is less than or equal to the corrected termination voltage, the mechanism of stopping discharge is immediately triggered; The linear decay function is expressed as: , where: V(t) is the voltage at time t, is the initial voltage, k is the decay constant, which determines the voltage drop per unit time. According to the linear decay function, the voltage is set to Exponential decay is performed. When the correction termination voltage is reached, the system stops discharging in time and also monitors the voltage in real time. and compared with the corrected termination voltage. Once the monitored voltage is less than or equal to the corrected termination voltage, the discharge stop mechanism is immediately triggered.

[0012] The technical effects and advantages of the battery online monitoring and intelligent capacity verification device of the present invention are as follows: Simplifying the three-level correction into two levels not only retains the consideration of the main influencing factors, but also simplifies the calculation process. For some situations where the accuracy requirements are not extremely high, the first and second level corrections can still make a more reasonable adjustment to the termination voltage without excessively increasing the calculation complexity. Make full use of the data of the built-in sensors and the historical usage data of the battery to make the correction decision based on evidence, improve the reliability and accuracy of the entire system, and select different functions according to the actual situation, which helps to optimize the voltage attenuation processing in the entire online capacity core process, while ensuring accuracy, and improving the overall performance and efficiency of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of the battery online monitoring and intelligent capacity verification device of the present invention. DETAILED DESCRIPTION

[0014] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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.

[0015] Example 1 The present invention Figure 1 As shown, a battery online monitoring and intelligent capacity verification device is disclosed, including: a correction classification module, a judgment correction module, a selection function module and an attenuation processing module, and the modules are signal connected.

[0016] Correction classification module: Add PTC resistance load as load correction, combine aging correction and temperature compensation to correct the original termination voltage of the battery as three-level correction, simplify the three-level correction as first-level correction and second-level correction; Judgment and correction module: obtains the temperature data of the built-in temperature sensor and the discharge current to judge whether the original termination voltage of the online core capacity is reasonable. If it is unreasonable, three-level correction is used. If it is reasonable, the correction level is comprehensively judged based on the consistency of the battery's charging state and the capacity attenuation, and the original termination voltage is corrected to the corrected termination voltage. Selected function module: Combine the accuracy requirements of the discharge process and whether the original termination voltage is reasonable to determine whether to select an exponential decay function or a linear decay function as the selected decay function; Attenuation processing module: Use the selected attenuation function and correct termination voltage to process the voltage attenuation process of the online core capacitor.

[0017] The functions of each module are as follows: In the information acquisition module, add PTC resistance load as load correction, combine aging correction and temperature compensation to correct the original termination voltage of the battery as the third-level correction, and simplify the third-level correction as the first-level correction and the second-level correction. The specific contents include: Load correction: Adding a PTC resistor load for correction is mainly used to smooth the voltage drop curve and flexibly adjust the termination voltage threshold. In some specific application scenarios, such as when a quick response to voltage changes or adjustment of discharge characteristics is required, the PTC resistor load can play a key role. However, in conventional applications, temperature compensation and aging correction are often more basic and generally applicable, while the PTC resistor load can be selectively added according to specific needs.

[0018] According to the rated voltage, rated current and expected load correction range of the battery, select a PTC resistor with appropriate rated power and initial resistance value, and connect the PTC resistor in series in the discharge circuit of the battery.

[0019] According to Ohm's law, the load correction of the PTC resistor is expressed as: =I× , where I is the discharge current of the battery, is the PTC resistor. During the discharge process, as time goes by, will rise, Increase, It also increases accordingly.

[0020] Temperature compensation correction: Temperature has a significant impact on battery performance. Temperature changes will directly lead to changes in battery internal resistance and voltage. In practical applications, batteries often face working conditions in different temperature environments, so temperature compensation is crucial to ensure the accuracy of the termination voltage. Accurate temperature compensation can reduce misjudgments caused by ambient temperature fluctuations and improve the stability and reliability of the battery system.

[0021] Use the temperature sensor to accurately measure the working environment temperature T of the battery. The measurement accuracy can be adjusted according to the actual needs and the type of battery (such as lead-acid battery, lithium-ion battery, etc.). Obtain its existing temperature-voltage characteristic curve and obtain the current standard temperature based on the curve. The temperature-voltage characteristic curve is obtained through a large number of experimental tests, which reflects the change law of the open circuit voltage or terminal voltage of the battery at different temperatures.

[0022] The measured temperature is T, and the standard temperature is , then the temperature deviation ΔT=T− The temperature compensation correction is expressed as: , where α is determined by different types of batteries and will not be elaborated here. If ΔT is positive and the temperature is higher than the standard temperature, then is a positive value; if ΔT is a negative value, the temperature is lower than the standard temperature, then For example, for a lead-acid battery, its voltage will drop significantly in a low temperature environment, about 3-5mV for every 10℃ drop. Assuming the average value is 4mV, the temperature compensation correction is: = ×ΔT. If the temperature is higher than the standard temperature, then is a positive value; if the temperature is lower than the standard temperature, Is a negative value.

[0023] Aging correction: As the battery is used for a longer time, it will age, which is manifested by changes in characteristics such as increased internal resistance and decreased capacity. The termination voltage threshold is adjusted according to the actual use of the battery to reflect its current performance status. Although aging is a gradual process, its long-term accumulation will have a significant impact on the performance of the battery, so aging correction is also an indispensable part.

[0024] Charge and discharge cycle statistics: Accurately record the number of charge and discharge cycles n of the battery. Generally speaking, the performance of the battery will be significantly reduced after a certain number of charge and discharge cycles (such as every 100 cycles of lead-acid batteries).

[0025] Assuming the number of charge and discharge cycles is n, the voltage correction value corresponding to each x% increase in internal resistance is , the internal resistance increases by z% every y cycles. Calculate the internal resistance increase ratio p=ny×z%, the voltage correction value caused by the increase in internal resistance =p× .

[0026] Assume that the increase in internal resistance is ΔR, and determine the relationship coefficient k between the increase in internal resistance and the voltage correction value according to the aging model of different types of batteries. The voltage correction value caused by the increase in internal resistance is =k×ΔR.

[0027] Based on both the number of cycles and the internal resistance measurement, the final aging correction value is expressed as: + .

[0028] Take lithium-ion batteries as an example: Assume that the voltage correction value corresponds to a 10% increase in internal resistance. =2.5mV, the internal resistance increases by 10% every 100 cycles, and the number of charge and discharge cycles is n.

[0029] First calculate the internal resistance increase ratio p= ×10%= , voltage correction value due to increase in internal resistance =p× = ×2.5= mV, assuming the increase in internal resistance is ΔR, for lithium-ion batteries, assuming the relationship coefficient k=0.25mV / mΩ, the voltage correction value caused by the increase in internal resistance =k×ΔR==0.25×ΔRmV, the final aging correction value is expressed as and .

[0030] The original termination voltage is known to be , the temperature compensation correction value calculated above is , aging correction value and PTC resistor load correction value Add together to get the corrected termination voltage . To summarize, from a general perspective, the importance of these three correction measures is ranked as follows: temperature compensation > aging correction > PTC resistance load.

[0031] Therefore, adding PTC resistance load as load correction, combining aging correction and temperature compensation to correct the original termination voltage of the battery as the third-level correction, according to the importance of the three correction measures, only using aging correction and temperature compensation to correct the original termination voltage of the battery as the second-level correction, the corrected termination voltage is expressed as: , only use temperature compensation to correct the original termination voltage of the battery as the first-level correction, and the corrected termination voltage is expressed as: .

[0032] In the judgment and correction module, the temperature data and discharge current of the built-in temperature sensor are obtained to judge whether the original termination voltage of the online core capacity is reasonable. If it is unreasonable, the three-level correction is used. If it is reasonable, the correction level is comprehensively judged in combination with the consistency of the battery's charging state and the capacity attenuation, and the original termination voltage is corrected to the corrected termination voltage. The specific contents include: The temperature sensor is used to accurately measure the working environment temperature T of the battery, and the measurement accuracy can be set to ±0.5°C. The current sensor is used to measure the real-time discharge current I of the battery during the discharge process.

[0033] According to the type of battery, the relationship model of temperature-discharge current-termination voltage can be established through a large amount of experimental data and theoretical analysis. For example, for lead-acid batteries, within a certain discharge current range, the termination voltage will fluctuate within a certain range for every 10°C change in temperature (e.g., the terminal voltage may drop by 3-5mV for every 10°C decrease in temperature).

[0034] Substitute the obtained temperature T and discharge current I into the reference model to calculate the theoretically reasonable termination voltage range arrive , and obtain the actual termination voltage of the current online core capacity process ,if or , then the original termination voltage is judged to be unreasonable and needs to be corrected at level three. When the original termination voltage is determined to be reasonable, the correction level is further determined.

[0035] Check the consistency of charging status: obtain the battery charging history and count the number of times the charging voltage exceeds the target charging voltage in the recent charging cycle. and the number of times the target charging voltage falls below the lower limit ,when + =0, the charging state consistency is considered good; when + ≤2, the charging state is considered to be relatively consistent; if + >2, the charging status is considered inconsistent.

[0036] Assume the total number of charging cycles is N, when + =0, S=0; when + ≤2, S= ×0.5; when + >2, S= (The value range of S is 0−1).

[0037] For capacity attenuation, the rated capacity of the battery is used and the actual capacity Q measured recently to calculate the capacity retention rate C = When C ≥ 90%, it is defined as mild attenuation; when 80% ≤ C < 90%, it is defined as moderate attenuation; if C < 80%, it is defined as severe attenuation.

[0038] When C ≥ 90%, D = 0; when 80% ≤ C < 90%, D = (90% − C) × 10; when C < 80%, D = (90% − C) × 20 (the value range of D is 0 − 20).

[0039] Combined with the battery's charge state consistency and capacity attenuation, the correction level is comprehensively determined: 1. Level 1 correction (simple case) When S=0 and D=0, only temperature compensation correction is required, and the correction level is level one.

[0040] 2. Second level correction (general situation) When S<=0.3 and D<=10, in addition to temperature compensation, capacity attenuation is taken into account for correction, and the correction level is level 2.

[0041] 3. Level 3 correction (complex situations) When S>0.3 or D>10, correction is made by comprehensively considering the charging state, capacity attenuation and temperature compensation, and the correction level is level three.

[0042] For example: a battery has N=10 charging cycles. =1, =0, then S= ×0.5=0.05; when its capacity retention rate C=85%, then D=(90%−85%)×10=5. In this case, it may be necessary to consider capacity attenuation and make a secondary correction.

[0043] In the selected function module, the exponential decay function or the linear decay function is selected as the selected decay function based on the accuracy requirements of the discharge process and whether the original termination voltage is reasonable. The specific contents include: For battery systems that have been put into use, historical operating data is obtained, including voltage and current records during the discharge process and subsequent performance changes of the battery. By analyzing these data, the accuracy requirements of the discharge process can be inferred. If the battery has obvious performance degradation or failure due to insufficient accuracy during certain discharge processes, determine the accuracy level that needs to be achieved in these cases, and set thresholds to determine the accuracy requirements of the discharge process.

[0044] After the selected function module receives the accuracy requirement of the discharge process and whether the original termination voltage is reasonable, the accuracy requirement of the discharge process and whether the original termination voltage is reasonable are defined as input variables, and they are divided into different fuzzy sets.

[0045] For example, "Low", "Medium", "High" for the accuracy requirements of the discharge process, "Yes", "No" for whether the original termination voltage is reasonable.

[0046] Defines the selected decay function as the output variable, partitioning it into fuzzy sets, for example, "Index", "Linear" for the selected decay function.

[0047] Formulate a set of fuzzy rules to describe the impact of different input variables on output variables. The definition of rules can be based on professional knowledge or obtained through data analysis and experiments. For example: The accuracy requirement of the discharge process is marked as A, whether the original termination voltage is reasonable is marked as P, and the selected decay function is marked as Decay Function. Rule 1: IF (A is High) AND (P is Yes) THEN (Decay Function is Index) Rule 2: IF (A is Low) AND (P is No) THEN (Decay Function is Linear) Fuzzy reasoning is performed according to fuzzy rules to determine the scheme for selecting the attenuation function.

[0048] It should be noted that the division of fuzzy sets can be adjusted according to actual conditions. For example, although this embodiment takes three fuzzy sets as examples, in fact, the accuracy requirements of the discharge process, whether the original termination voltage is reasonable, and the selected attenuation function can be divided into more than three sets to facilitate better precise adjustment according to different temperatures.

[0049] Furthermore, for the accuracy requirements of the discharge process, whether the original termination voltage is reasonable, a threshold value can be set according to the actual situation for judgment, which will not be elaborated here.

[0050] In the attenuation processing module, the voltage attenuation process of the online core capacitor is processed using the selected attenuation function and the modified termination voltage. The specific contents include: The exponential decay function is expressed as: ,in: is the voltage at time t, is the initial voltage, τ is the time constant that determines the decay rate, and e is the base of the natural logarithm. Exponential decay is performed. When the correction termination voltage is reached, the system stops discharging in time and monitors the voltage in real time. and compared with the corrected termination voltage. Once the monitored voltage is less than or equal to the corrected termination voltage, the discharge stop mechanism is immediately triggered.

[0051] It should be noted that the time constant τ is set by technicians in this field according to actual conditions and will not be described in detail here. The characteristic of the exponential decay function is that the voltage decreases exponentially with time, with a faster decrease in the initial stage and a gradual slowdown in the later stage. It is more in line with the nonlinear characteristics of the actual battery discharge process and can better simulate the behavior of the battery in the initial stage of discharge and when it is close to the termination voltage.

[0052] The linear decay function is expressed as: , where: V(t) is the voltage at time t, is the initial voltage, k is the decay constant, which determines the voltage drop per unit time. Exponential decay is performed. When the correction termination voltage is reached, the system stops discharging in time and also monitors the voltage in real time. and compared with the corrected termination voltage. Once the monitored voltage is less than or equal to the corrected termination voltage, the discharge stop mechanism is immediately triggered.

[0053] It should be noted that the attenuation constant k is set by technicians in this field according to actual conditions and will not be described in detail here. The characteristic of the linear attenuation function is that the voltage decreases linearly with time, and the decrease amplitude in each time period is the same. The calculation is simple and easy to implement, but it may not be accurate enough in some cases, especially at the beginning of discharge and close to the termination voltage.

[0054] The above formulas are all dimensionless and numerical calculations. The formula is a formula for the most recent real situation obtained by collecting a large amount of data and performing software simulation. The preset parameters in the formula are set by technicians in this field according to actual conditions.

[0055] The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination. When implemented by software, the above embodiments may be implemented in whole or in part in the form of a computer program product.

[0056] Those of ordinary skill in the art will appreciate that the modules and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application of the technical solution and the invention constraints. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0057] In addition, each functional module in each embodiment of the present application may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module.

[0058] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0059] 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. Battery online monitoring and intelligent capacity verification device, characterized in that: include: Correction classification module, judgment correction module, selection function module and attenuation processing module, and signal connection between each module; Correction classification module: Add PTC resistance load as load correction, combine aging correction and temperature compensation to correct the original termination voltage of the battery as three-level correction, simplify the three-level correction as first-level correction and second-level correction; Judgment and correction module: obtains the temperature data of the built-in temperature sensor and the discharge current to judge whether the original termination voltage of the online core capacity is reasonable. If it is unreasonable, three-level correction is used. If it is reasonable, the correction level is comprehensively judged based on the consistency of the battery's charging state and the capacity attenuation, and the original termination voltage is corrected to the corrected termination voltage. Selected function module: Combine the accuracy requirements of the discharge process and whether the original termination voltage is reasonable to determine whether to select an exponential decay function or a linear decay function as the selected decay function; Attenuation processing module: Use the selected attenuation function and correct termination voltage to process the voltage attenuation process of the online core capacitor.

2. The battery online monitoring and intelligent capacity verification device according to claim 1 is characterized in that: Load correction: Add a PTC resistor load for correction, select a PTC resistor with appropriate rated power and initial resistance value, connect the PTC resistor in series in the battery discharge circuit, and record the PTC resistor as , let the discharge current of the battery be I, and the load correction of the PTC resistor be expressed as: =I× , where I is the discharge current of the battery, is the PTC resistor; Temperature compensation correction: record the working environment temperature of the battery measured by the temperature sensor as T, obtain the temperature-voltage characteristic curve of the battery, and obtain the current standard temperature based on the curve , then the temperature deviation , the temperature compensation correction is expressed as: , where α is determined by different types of batteries; Aging correction: record the number of battery charge and discharge cycles as n, and record the voltage correction value corresponding to each x% increase in internal resistance. , the internal resistance increases by z% every y cycles, and the internal resistance increase ratio p=ny×z%. The voltage correction value caused by the internal resistance increase is expressed as: =p× , assuming that the increase in internal resistance is ΔR, the relationship coefficient k between the increase in internal resistance and the voltage correction value is determined according to the aging model of different types of batteries. The voltage correction value caused by the increase in internal resistance is expressed as: =k×ΔR, the final aging correction value is expressed as: + ; The original termination voltage is , the temperature compensation correction value calculated above is , aging correction value and PTC resistor load correction value Add together to get the corrected termination voltage ; The importance of the three correction measures is ranked as follows: temperature compensation > aging correction > PTC resistor load. Adding PTC resistor load as load correction, combining aging correction and temperature compensation to correct the original termination voltage of the battery as the third-level correction. According to the importance of the three correction measures, only aging correction and temperature compensation are used to correct the original termination voltage of the battery as the second-level correction. The corrected termination voltage is expressed as: , only use temperature compensation to correct the original termination voltage of the battery as the first-level correction, and the corrected termination voltage is expressed as: .

3. The battery online monitoring and intelligent capacity verification device according to claim 2 is characterized in that: Record the working environment temperature of the battery measured by the temperature sensor as T, record the discharge current of the battery as I, establish the relationship model of temperature-discharge current-termination voltage, substitute the obtained temperature T and discharge current I into the reference model, and calculate the theoretically reasonable termination voltage range arrive , and obtain the actual termination voltage of the current online core capacity process ,when or When the original termination voltage is judged to be unreasonable, a three-level correction is required. When the original termination voltage is judged to be reasonable, the correction level is further judged; Check the consistency of charging status: obtain the battery charging history and count the number of times the charging voltage exceeds the target charging voltage in the recent charging cycle. and the number of times the target charging voltage falls below the lower limit ,when + =0, the charging state consistency is considered good; when + ≤2, the charging state is considered to be relatively consistent; if + >2, the charging status is considered inconsistent; Assume the total number of charging cycles is N, when + =0, S=0; when + ≤2, S= ×0.5; when + >2, S= (The value range of S is 0-1); Judgment of capacity attenuation: Based on the rated capacity of the battery and the actual capacity Q measured recently to calculate the capacity retention rate C = , when C ≥ 90%, it is defined as mild attenuation; when 80% ≤ C < 90%, it is defined as moderate attenuation; if C < 80%, it is defined as severe attenuation; When C ≥ 90%, D = 0; when 80% ≤ C < 90%, D = (90% − C) × 10; when C < 80%, D = (90% − C) × 20, (the value range of D is 0 − 20); Combined with the battery's charge state consistency and capacity attenuation, the correction level is comprehensively determined:

1. Level 1 correction: When S=0 and D=0, only temperature compensation correction is required, and the correction level is level 1; 2. Level 2 correction: When S<=0.3 and D<=10, in addition to temperature compensation, the capacity attenuation is taken into account for correction, and the correction level is level 2; 3. Level 3 correction: When S>0.3 or D>10, the correction is made by comprehensively considering the charging state, capacity attenuation and temperature compensation, and the correction level is level 3.

4. The battery online monitoring and intelligent capacity verification device according to claim 3 is characterized in that: Obtain the historical operation data of the battery system that has been put into use, analyze the historical data, obtain the accuracy requirements of the discharge process, and set the threshold to determine the accuracy requirements of the discharge process; After the selected function module receives the accuracy requirement of the discharge process and whether the original termination voltage is reasonable, the accuracy requirement of the discharge process and whether the original termination voltage is reasonable are defined as input variables, and they are divided into different fuzzy sets respectively; Define the selected decay function as the output variable and partition it into fuzzy sets; Formulate fuzzy rules to describe the accuracy requirements of the discharge process and the influence of the reasonable definition of the original termination voltage on the selected decay function; Fuzzy reasoning is performed according to fuzzy rules to determine the selected attenuation function.

5. The battery online monitoring and intelligent capacity verification device according to claim 4 is characterized in that: The exponential decay function is expressed as: ,in: is the voltage at time t, is the initial voltage, τ is the time constant, e is the base of the natural logarithm, and the voltage is set to decrease from the initial value according to the exponential decay function. Exponential decay is performed. When the correction termination voltage is reached, the system stops discharging in time and monitors the voltage in real time. and compare it with the corrected termination voltage. Once the monitored voltage is less than or equal to the corrected termination voltage, the mechanism of stopping discharge is immediately triggered; The linear decay function is expressed as: , where: V(t) is the voltage at time t, is the initial voltage, k is the decay constant, which determines the voltage drop per unit time. According to the linear decay function, the voltage is set to Exponential decay is performed. When the correction termination voltage is reached, the system stops discharging in time and also monitors the voltage in real time. and compared with the corrected termination voltage. Once the monitored voltage is less than or equal to the corrected termination voltage, the discharge stop mechanism is immediately triggered.

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