Battery health state determination method, energy storage equipment and storage medium

Abstract

The invention relates to the technical field of new energy, in particular to a battery health state determination method, energy storage equipment and a storage medium, which are used for improving the calculation accuracy of a battery health state value. According to the main scheme, when a target battery pack meets the full-charge and full-discharge conditions, the full-charge capacity value of the target battery pack at the current moment is calculated through a full-charge and full-discharge method; when the target battery pack meets the low-end full-charge condition, calculating a full-charge capacity value of the target battery pack at the current moment through a two-point method; according to the full-charge capacity value at the current moment and the full-charge capacity value at the previous moment, calculating to obtain a real battery health state value at the current moment; and carrying out amplitude limiting processing on the real battery health state value at the current moment to obtain a displayed battery health state value at the current moment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new energy, in particular to a battery state of health determination method, energy storage equipment and a storage medium. BACKGROUND

[0002] A battery pack is an energy source of a new energy product. In order to ensure that the new energy product can be safely, stably and efficiently operated, the battery needs to be managed and controlled. The state of health (SOH) of the battery is one of the most important parameters in the battery management system. Accurate mastery of the SOH of the battery pack can provide a basis for detection and diagnosis, help to timely understand the health status of each single battery of the battery pack, timely replace the aged single battery, improve the overall life of the battery pack, and further improve the performance of the battery pack. Therefore, timely and accurate estimation of the SOH of the battery pack is of great significance.

[0003] It is found through research that the temperature, charge-discharge rate, depth of discharge (DOD), calendar life and other factors of the battery will affect the aging degree of the battery. Then a large number of cross experiments can be performed according to the calendar life, temperature, charge-discharge rate, DOD and the like, so as to obtain the size of the calculated SOH.

[0004] However, the use scene of the new energy product is relatively complex, and the DOD, rate and temperature are greatly related to the region, season and user habit. The battery attenuation track calibrated by experiments alone cannot be fitted to the actual working condition, and the method cannot be corrected in a closed loop, so the SOH of the battery cannot be accurately evaluated. SUMMARY

[0005] Therefore, the present application provides a battery state of health determination method, energy storage equipment and a storage medium, which are used to improve the accuracy of battery state of health value calculation.

[0006] In a first aspect, an embodiment of the present application provides a battery state of health determination method, which comprises the following steps:

[0007] When the target battery pack meets the full charge and full discharge condition, the full charge capacity value of the target battery pack at the current time is calculated by a full charge and full discharge method;

[0008] When the target battery pack meets the low-end full charge condition, the full charge capacity value of the target battery pack at the current time is calculated by a two-point method;

[0009] The real battery state of health value at the current time is calculated according to the full charge capacity value at the current time and the full charge capacity value at the previous time;

[0010] The true battery health state value at the current time is limited to obtain a display battery health state value at the current time.

[0011] In an optional embodiment provided by the application, the full charge capacity value of the target battery pack at the current time is calculated by a two-point method, including:

[0012] The effective flag, the capacity retention rate, the first SOC value, and the second SOC value in the battery state of charge parameter are obtained, the first SOC value is less than a preset percentage, and the second SOC value is an SOC value in a full charge state.

[0013] If the effective flag is valid, the full charge capacity value of the target battery pack at the current time is calculated according to the capacity retention rate, the first SOC value, and the second SOC value.

[0014] In an optional embodiment provided by the application, the full charge capacity value of the target battery pack at the current time is calculated according to the capacity retention rate, the first SOC value, and the second SOC value, including:

[0015] The full charge capacity value of the target battery pack at the current time is calculated by the following formula:

[0016]

[0017] wherein, SOC Low is the first SOC value, DesignCap is the rated capacity of the target battery pack, DeltaCap is the capacity difference of the target battery pack between the first SOC value and the second SOC value, and RetenSoc is the capacity retention rate of the target battery pack under the current working condition.

[0018] In an optional embodiment provided by the application, the full charge capacity value of the target battery pack at the current time is calculated by a full charge and full discharge method, including:

[0019] The capacity retention rate, the second SOC value, and the third SOC value in the battery state of charge parameter are obtained, the third SOC value is an SOC value in a full discharge state, and the second SOC value is an SOC value in a full charge state.

[0020] The full charge capacity value of the target battery pack at the current time is calculated according to the capacity retention rate, the second SOC value, and the third SOC value.

[0021] In an optional embodiment provided by the application, the full charge capacity value of the target battery pack at the current time is calculated according to the capacity retention rate, the second SOC value, and the third SOC value, including:

[0022] The full charge capacity value of the target battery pack at the current time is calculated by the following formula:

[0023]

[0024] wherein, ΔCap is the capacity difference of the target battery pack between the second SOC value and the third SOC value, RetenSoc FullDsg is the capacity retention rate of the target battery pack under the current working condition, and DesignCap is the rated capacity of the target battery pack.

[0025] In an optional embodiment provided by the present application, the real battery health state value at the current time is calculated according to the full charge capacity value at the current time and the full charge capacity value at the last time, and the calculation includes:

[0026] The full charge capacity at the current time and the full charge capacity at the last time are weighted to obtain an effective full charge capacity.

[0027] The ratio of the effective full charge capacity and the rated capacity of the target battery pack is calculated to obtain the real battery health state value at the current time.

[0028] In an optional embodiment provided by the present application, the method further includes:

[0029] The time difference between the current time and the last time and the battery cycle number difference between the current time and the last time are calculated.

[0030] The weight value of the full charge capacity value at the current time is calculated according to the time difference and the battery cycle number difference.

[0031] In an optional embodiment provided by the present application, the method further includes:

[0032] The battery cycle number at the current time of the target battery pack is obtained.

[0033] The lower limit battery health state at the current time of the target battery pack is determined according to the battery cycle number and a preset battery attenuation curve.

[0034] The lower limit battery health state at the current time is determined as the lower limit value of the limiting processing.

[0035] In the second aspect, the embodiments of the present application further provide a battery health state determination device, which includes:

[0036] A first calculation module is configured to calculate the full charge capacity value of the target battery pack at the current time by the full charge full discharge method when the target battery pack meets the full charge full discharge condition.

[0037] The second calculation module is configured to calculate the full-charge capacity value of the target battery pack at the current time point by using a two-point method when the target battery pack meets a low-end full-charge condition.

[0038] The third calculation module is configured to calculate a real battery health state value at the current time point according to the full-charge capacity value at the current time point and a full-charge capacity value at a previous time point.

[0039] The limiting module is configured to limit the real battery health state value at the current time point to obtain a display battery health state value at the current time point.

[0040] In a third aspect, an embodiment of the present application further provides a storage device, including a processor, a memory and a bus, the memory stores machine readable instructions executable by the processor, when the electronic device is running, the processor and the memory communicate through the bus, and the machine readable instructions are executed by the processor to perform the steps of the battery health state determination method in the first aspect.

[0041] In a fourth aspect, an embodiment of the present application further provides a computer readable storage medium, and the computer readable storage medium stores a computer program, and the computer program is executed by the processor to perform the steps of the battery health state determination method in the first aspect.

[0042] The battery health state determination method, the storage device and the storage medium provided in the embodiments of the present application calculate the full-charge capacity value of the target battery pack at the current time point by using a full-charge full-discharge method when the target battery pack meets a full-charge full-discharge condition, calculate the full-charge capacity value of the target battery pack at the current time point by using a two-point method when the target battery pack meets a low-end full-charge condition, calculate a real battery health state value at the current time point according to the full-charge capacity value at the current time point and a full-charge capacity value at a previous time point, and limit the real battery health state value at the current time point to obtain a display battery health state value at the current time point. The embodiments of the present application calculate the full-charge capacity value at the current time point by using different algorithms when different charging and discharging conditions are met, then calculate the real battery health state value at the current time point according to the full-charge capacity value at the current time point and the full-charge capacity value at the previous time point, and limit the real battery health state value to obtain the display battery health state value, so that the display battery health state value follows the effect of only decreasing but not increasing, thereby improving the accuracy of battery health state value calculation.

[0043] In order to make the above objectives, characteristics and advantages of the present application more apparent and easy to understand, the following preferred embodiments are described in detail below, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed in the embodiments. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be considered as limiting the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0045] Figure 1 A flow chart of a method for determining battery state of health is shown;

[0046] Figure 2 A structural block diagram of a device for determining battery state of health is shown;

[0047] Figure 3 A schematic diagram of an energy storage device is shown. DETAILED DESCRIPTION

[0048] The terms "first", "second", and "third" and the like in the specification and claims of the present application and the above drawings are used to distinguish different objects, and are not intended to limit a specific order.

[0049] In the embodiments of the present application, the words "exemplary" or "for example" are used to mean serving as an example, instance, or illustration. Any embodiment or design presented as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or advantageous than other embodiments or design solutions. Rather, the use of "exemplary" or "for example" is intended to present concepts in a concrete manner. The use of "exemplary" or "for example" is intended to present concepts in a concrete manner.

[0050] In the description of the present application, unless otherwise specified, " / " represents that the objects before and after the " / " are in an "or" relationship, for example, A / B can represent A or B; "and / or" in the present application is only a description of the relationship between the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent: A alone, A and B together, and B alone, where A and B can be singular or plural. In addition, in the description of the present application, unless otherwise specified, "multiple" means two or more than two. "At least one of the following" or the like means any combination of the items, including any combination of single item or multiple items. For example, at least one of a, b, or c can represent: a, b, c, a-b, a-c, b-c, or a-b-c, where a, b, and c can be single or multiple.

[0051] In the embodiments of the present application, at least one can also be described as one or more, and multiple can be two, three, four, or more, which is not limited by the present application.

[0052] As Figure 1 shown, the embodiment of the present application provides a battery state of health determination method, the battery state of health determination method provided by the present application can include:

[0053] S10, when the target battery pack meets the full charge and full discharge condition, the full charge capacity value of the target battery pack at the current time is calculated by the full charge and full discharge method.

[0054] In order to improve the robustness of the full charge and full discharge method, the logic trigger of the full charge and full discharge method is conditionally limited, that is, the full charge and full discharge condition met by the target battery pack can include one or more of the following conditions: the temperature during full charge and full discharge is greater than 15℃, the current during full charge and full discharge is less than 0.5C (battery rated capacity), the interval between full charge and full discharge does not exceed 24 hours, the cumulative charging capacity between full charge and full discharge does not exceed 2C, the cumulative discharging capacity between full charge and full discharge does not exceed 2C, the cumulative time of current less than 0.2C does not exceed 2h, ΔQ is between 0.2C-1.2C, and the total capacity retention rate is greater than 70%. In other embodiments, the full charge and full discharge condition met by the target battery pack can also include one or more of the following conditions: the real-time clock RTC of the device during full charge and full discharge, and the storage flash does not have a fault. For example, if the real-time clock RTC and / or the storage flash has a fault, it is not considered that the full discharge and full discharge condition is not met at present.

[0055] It should be noted that the full charge and full discharge method in the related art is to record the full charge capacity or the full discharge capacity after the battery is discharged and then full charged or after the battery is charged and then full discharged, and then compare the full charge capacity or the full discharge capacity with the rated capacity, so that the full charge capacity of the battery can be obtained. The advantage is that the full charge capacity calculated by one full charge and full discharge condition is a real calculation, that is, the accuracy and real-time performance are good, the calculated full charge capacity value is robust, and closed-loop correction can be achieved to a certain extent. However, in the actual charging process by the full charge and full discharge method, the full charge capacity value will be affected by the charging rate and temperature, that is, different charging rates or temperatures will affect the actual full charge capacity value of the battery, thereby affecting the real full charge capacity value. For example, a larger charging rate or low-temperature charging results in a smaller actual full charge capacity value of the battery; and a smaller charging rate or high-temperature charging results in a larger actual full charge capacity value of the battery.

[0056] The present application optimizes the calculation of the full charge capacity value to solve the problem that the full charge capacity value calculated by the full charge and full discharge method in the related art is affected by the charging rate and temperature.

[0057] In an optional embodiment, the process of calculating the full charge capacity value of the target battery pack at the current time by the full charge and full discharge method is as follows:

[0058] S101, acquire the capacity retention rate, the second SOC value, and the third SOC value in the battery state of charge parameter.

[0059] Specifically, the embodiment can determine the capacity retention rate, the second SOC value, and the third SOC value from the battery state of charge parameter. The third SOC value is the SOC value in the full discharge state, and the second SOC value is the SOC value in the full charge state.

[0060] It can be understood that various models or methods for calculating or estimating battery state of charge parameters such as the capacity retention rate, the SOC value, and the like are present in the related art, and therefore, the present application does not limit the method for determining the battery state of charge parameter. For example, the SOC value can be calculated by the ampere-hour integration method, the capacity retention rate can be calculated after each cycle of the battery, and the battery state of charge parameter can be estimated by a preset model after multiple training.

[0061] For example, the capacity retention rate in the embodiment can be determined by a preset SOC model according to the charge rate and the temperature. Specifically, the corresponding capacity retention rate can be determined by looking up the capacity retention rate table shown in Table 1 below, such as a charge rate of 1C and a current temperature of -10℃. According to the lookup of Table 1 below, the capacity retention rate is determined to be 62%. Thus, the capacity retention rate determined by the present embodiment fully considers the influence of different temperatures and charge rates on the full charge capacity value in the charging and discharging process.

[0062] Table 1

[0063]

[0064] In the embodiment, the calculation method of the capacity retention rate in Table 1 above is as follows: under normal temperature conditions, the battery is fully charged according to the standard working condition and is fully rested. The temperature of the constant temperature box is set to discharge to the cut-off voltage at a fixed charge rate C1 to reach the full discharge. Assuming that the temperature of the battery cell reaching the cut-off voltage is T2, and the discharged capacity is cap, then the capacity retention rate at temperature T2 and rate C1 is cap / rated capacity x 100%.

[0065] S102, calculate the full charge capacity value of the target battery pack at the current time according to the capacity retention rate, the second SOC value, and the third SOC value.

[0066] Specifically, the embodiment can calculate the full charge capacity value of the target battery pack at the current time by the following formula:

[0067]

[0068] Wherein, ΔCap is the capacity difference of the target battery pack between the second SOC value and the third SOC value, i.e. the capacity change from full charge to full discharge or from full discharge to full charge, and the unit is mAh; RetenSoc FullDsg is the capacity retention rate of the target battery pack under the current working condition, and DesignCap is the rated capacity of the target battery pack, and the unit is mAh.

[0069] In the embodiment, when calculating the full charge capacity value at the current time, the capacity retention rate is added to the algorithm calculation. As described above, the capacity retention rate is different under different working conditions, such as different temperatures and charge / discharge rates, so adding the capacity retention rate considers the temperature and the rate, which can accurately and quickly correct the full charge capacity value at the current time under the conditions of large rate and low temperature, and can make the calculated full charge capacity value at the current time more accurate.

[0070] S20, when the target battery pack meets the low-end full charge condition, the full charge capacity value of the target battery pack at the current time is calculated by the two-point method.

[0071] Specifically, the two-point method under the low-end full charge condition refers to selecting two points in the non-platform region of the battery SOC-OCV curve to calculate the full charge capacity. For example, a certain discharge point in the region with a SOC less than a preset percentage (for example, 30%) is selected as the first point (low-end point), and the full charge point is selected as the other point, and the full charge capacity value is calculated on this basis. Similar to the full charge and full discharge method, the low-end full charge method meets the following conditions to update and calculate the full charge capacity value at the current time: the temperature is greater than 15℃ when full charging, the interval between the low-end and the full charging is not more than 24 hours, the cumulative charging capacity between the low-end and the full charging is not more than 2C, the cumulative discharging capacity between the low-end and the full charging is not more than 1C, the cumulative time of the current less than 0.2C is not more than 2h, ΔQ is between 0.2C-1.2C, the capacity retention rate is greater than 90% when full charging, RTC and flash are effective, and the like.

[0072] In an optional embodiment provided in the application, the full charge capacity value of the target battery pack at the current time is calculated by the two-point method, comprising:

[0073] S201, obtaining the effective flag bit, the capacity retention rate, the first SOC value and the second SOC value in the battery state of charge parameter.

[0074] Wherein, the effective flag bit is used to represent whether the low-end point is effective. The first SOC value is less than a preset percentage, i.e. the SOC value corresponding to the low-end point, and the second SOC value is the SOC value in the full charging state.

[0075] The first SOC value and the second SOC value are determined by the non-platform region of the SOC-OCV curve, so that the error of SOH can be reduced. Because the SOC is in the non-platform region between 0% and 30%, the SOC value obtained by OCV is more accurate. Specifically, the first SOC value is determined as the SOC of the first low end point obtained in the range of 0-30% after the target battery pack is powered on, and the full charge point is taken as the second SOC value.

[0076] In the embodiment, considering the different capacities released at different temperatures and different charge rates in the charging and discharging process, the capacity retention rate is also considered in the low-end full charge algorithm, that is, the capacity retention rate table shown in Table 1 is used to determine the capacity retention rate at different temperatures and different charge rates. Thus, the capacity retention rate can be calculated according to different temperatures and different charge rates through the embodiment.

[0077] S202, if the valid flag is valid, the full charge capacity value of the target battery pack at the current time is calculated according to the capacity retention rate, the first SOC value and the second SOC value.

[0078] The valid flag in the battery state of charge parameter in the embodiment can be transmitted by the SOC model. The logic is as follows: after power on, if the minimum cell voltage is less than 3280mV (i.e., it is a non-platform region), the current power-on time-last power-off time>2h, the BMS state is static, the collected terminal voltage is almost the OCV value, the voltage, temperature and flash are valid, and the collected data of voltage, temperature, etc. are valid, it is considered that the valid flag is valid.

[0079] Specifically, the full charge capacity value of the target battery pack at the current time is calculated according to the capacity retention rate, the first SOC value and the second SOC value, including: the full charge capacity value of the target battery pack at the current time is calculated by the following formula:

[0080]

[0081] SOC Low is the first SOC value, DesignCap is the rated capacity of the target battery pack, ΔCap is the capacity difference of the target battery pack between the first SOC value and the second SOC value, and RetenSoc is the capacity retention rate of the target battery pack under the current working condition.

[0082] It can be known from the above calculation formula that the calculation of the full charge capacity value in the embodiment is corrected by using the capacity retention rate RetenSoc, and therefore the calculation of the full charge capacity value contains the unusable capacity, so that the calculated full charge capacity value is more accurate. In addition, the capacity retention rate in the embodiment is calculated by the SOC model according to the real-time temperature and the charge rate, so that the full charge capacity value at the current time is obtained by the joint calculation of the SOC and the SOH algorithm, the full charge capacity value at the current time can be accurately and quickly corrected under the conditions of high rate and low temperature, and the calculated full charge capacity value at the current time is relatively accurate.

[0083] S30, calculating a real battery health state value at the current time according to the full charge capacity value at the current time and the full charge capacity value at the last time.

[0084] In an optional embodiment provided in the application, the real battery health state value at the current time is calculated according to the full charge capacity value at the current time and the full charge capacity value at the last time, comprising:

[0085] S301, performing weighted calculation on the full charge capacity value at the current time and the full charge capacity value at the last time to obtain an effective full charge capacity.

[0086] In the embodiment, only when the full charge and discharge condition and the low-end full charge condition are triggered, the full charge capacity value is updated in the process of battery charging and discharging, otherwise the full charge capacity value remains the full charge capacity value at the last time. It is assumed that the full charge capacity value at k-1 time is Cap k-1 . Specifically, if the full charge and discharge condition is triggered at k time, the updated calculation full charge capacity value is Cap k = Cap FCC ; if the low-end full charge condition is triggered at k time, the updated calculation full charge capacity value is Cap k = Cap DqDsoc . The current time full charge capacity value Cap k and the last time full charge capacity value Cap k-1 are weighted to obtain the current time effective full charge capacity FullCap k by low-pass filtering.

[0087] The determination process of the weight value of the full charge capacity value at the current time is that the time difference between the current time and the last time and the cycle number difference of the battery between the current time and the last time are calculated, and the weight value of the full charge capacity value at the current time is calculated according to the time difference and the cycle number difference of the battery.

[0088] It should be noted that the weight value in the embodiment meets the principle that the longer the time difference is, the more the battery cycle number cycle is, and the greater the weight value of the newly calculated full charge capacity value is. If the full charge capacity value calculated at the last time k-1 meets the full charge and discharge condition or the low-end full charge condition, the time Time k-1 and the battery cycle number Cycle k-1 at the last time will be recorded. If the full charge capacity value calculated at the current time k meets the full charge and discharge condition or the low-end full charge condition, the time Time k and the battery cycle number Cycle k at the current time will be recorded. Then, the time difference Δtime is obtained by calculating the difference between Time k and Time k-1 , and the battery cycle number difference ΔCycle is obtained by calculating the difference between Cycle k and Cycle k-1 , so as to obtain the weight factor1 by linear interpolation according to ΔTime (0.5 years, 0.1) (5 years, 1); the weight factor2 is obtained by linear interpolation according to ΔCycle (100 times, 0.1), (1000 times, 1), and finally the weight value Factor of the full charge capacity value at the current time is obtained by the following formula:

[0089]

[0090] Among them, factor1 is the weight obtained according to the interval time ΔTime, and factor2 is the weight obtained according to the battery cycle number difference ΔCycle.

[0091] Then, the effective full charge capacity FullCap k at the current time is calculated according to the obtained weight value Factor of the full charge capacity value at the current time.

[0092] FullCap k = Cap k × Factor + (1-Factor) × Cap k-1

[0093] Among them, the full charge capacity value at the current time k is Cap k , and the full charge capacity value at the last time k-1 is Cap k-1 .

[0094] S302, calculate the ratio of the effective full charge capacity and the rated capacity of the target battery pack, to obtain the real battery health state value at the current time.

[0095] After the effective full capacity and the rated capacity of the target battery pack are obtained, the real battery state of health value at the current time RealSoh is calculated according to the following formula k :

[0096]

[0097] wherein DesignCap is the rated capacity of the target battery pack.

[0098] S40, limiting the real battery state of health value at the current time to obtain a display battery state of health value at the current time.

[0099] The step of limiting the real battery state of health value at the current time in the embodiment is: obtaining the battery cycle number at the current time of the target battery pack; determining the lower limit battery state of health at the current time of the target battery pack according to the battery cycle number and the preset battery attenuation curve; and determining the lower limit battery state of health at the current time as the lower limit value of the limiting process.

[0100] It should be noted that, since the battery attenuation curve method needs a large number of cross calibration experiments, the battery attenuation trajectory calibrated by experiments alone cannot fit the actual working conditions, so it cannot accurately evaluate the full charge capacity value of the battery, and cannot achieve closed-loop correction. Therefore, in an embodiment, the scheme for determining the lower limit battery state of health at the current time of the target battery pack by the battery attenuation curve method is: only measuring the battery attenuation curve under severe working conditions, fixing the extreme temperature, extreme DOD, extreme charge-discharge rate and other influencing parameters, obtaining the preset battery attenuation curve, and determining the lower limit battery state of health at the current time of the target battery pack according to the battery cycle number and the preset battery attenuation curve. The charge-discharge cycle number is calculated by accumulating the charge-discharge capacity, so as to obtain the battery cycle number CycleSoh at the current time k , which is calculated by the battery attenuation curve method k as the lower limit, i.e. the display battery state of health value DispSoh k output to the user cannot exceed CycleSoh k .

[0101] Specifically, the DispSoh k-1 at the last time is taken as the upper limit of the limiter, CycleSoh k is taken as the lower limit of the limiter, RealSoh k is calculated by the limiter expressed by the following formula, to obtain the updated display battery state of health value DispSoh k , the display battery state of health value satisfies only decrease but not increase, and since RealSoh kThe filtering is performed at the time, and the display battery health state value is smooth and does not suddenly decrease.

[0102]

[0103] The method for determining the battery health state provided in the embodiments of the present application comprises the following steps: when the target battery pack meets the full-charge full-discharge condition, a full-charge capacity value of the target battery pack at a current time is calculated by using the full-charge full-discharge method; when the target battery pack meets the low-end full-charge condition, the full-charge capacity value of the target battery pack at the current time is calculated by using the two-point method; a real battery health state value at the current time is calculated according to the full-charge capacity value at the current time and a full-charge capacity value at a previous time; and a display battery health state value at the current time is obtained by limiting the real battery health state value at the current time. In the present application, different algorithms are used to calculate the full-charge capacity value at the current time under different charging and discharging conditions, and then the real battery health state value at the current time is calculated according to the full-charge capacity value at the current time and the full-charge capacity value at the previous time, and the display battery health state value is obtained by limiting the real battery health state value, so that the display battery health state value only decreases and does not increase, thereby improving the accuracy of the calculation of the battery health state value.

[0104] It can be understood that the method for determining the battery health state can be implemented by using the device for determining the battery health state, and in the case of dividing the functions into different functional modules, Figure 2 A possible composition schematic diagram of the device for determining the battery health state described above and in the examples is shown, as shown in the figure, Figure 2 The device for determining the battery health state can comprise:

[0105] The first calculation module 21 is configured to calculate the full-charge capacity value of the target battery pack at the current time by using the full-charge full-discharge method when the target battery pack meets the full-charge full-discharge condition.

[0106] The second calculation module 22 is configured to calculate the full-charge capacity value of the target battery pack at the current time by using the two-point method when the target battery pack meets the low-end full-charge condition.

[0107] The third calculation module 23 is configured to calculate the real battery health state value at the current time according to the full-charge capacity value at the current time and the full-charge capacity value at the previous time.

[0108] The limiting module 24 is configured to limit the real battery health state value at the current time to obtain the display battery health state value at the current time.

[0109] In an optional embodiment of the present application, the second calculation module 22 is specifically configured to:

[0110] An effective flag bit, a capacity retention rate, a first SOC value, and a second SOC value in a battery state of charge parameter are acquired, the first SOC value is less than a preset percentage, and the second SOC value is an SOC value in a full charge state;

[0111] If the effective flag bit is valid, a full charge capacity value of the target battery pack at a current time is calculated according to the capacity retention rate, the first SOC value, and the second SOC value.

[0112] In an optional embodiment provided by the application, the second calculation module 22 is specifically configured to:

[0113] The full charge capacity value of the target battery pack at the current time is calculated by the following formula:

[0114]

[0115] wherein, SOC Low is the first SOC value, DesignCap is a rated capacity of the target battery pack, DeltaCap is a capacity difference of the target battery pack between the first SOC value and the second SOC value, and RetenSoc is the capacity retention rate of the target battery pack under a current working condition.

[0116] In an optional embodiment provided by the application, the first calculation module 21 is specifically further configured to:

[0117] A capacity retention rate, a second SOC value, and a third SOC value in a battery state of charge parameter are acquired, the third SOC value is an SOC value in a full discharge state, and the second SOC value is an SOC value in a full charge state;

[0118] A full charge capacity value of the target battery pack at a current time is calculated according to the capacity retention rate, the second SOC value, and the third SOC value.

[0119] In an optional embodiment provided by the application, the first calculation module 21 is specifically further configured to:

[0120] The full charge capacity value of the target battery pack at the current time is calculated by the following formula:

[0121]

[0122] wherein, DeltaCap is a capacity difference of the target battery pack between the second SOC value and the third SOC value, RetenSoc FullDsg is a capacity retention rate of the target battery pack under a current working condition, and DesignCap is a rated capacity of the target battery pack.

[0123] In an optional embodiment provided by the present application, the third calculation module 23 is specifically configured to:

[0124] The effective full-charge capacity is obtained by weighted calculation of the current full-charge capacity value and the last full-charge capacity value.

[0125] The real battery health state value of the current time is obtained by calculating the ratio of the effective full-charge capacity and the rated capacity of the target battery pack.

[0126] In an optional embodiment provided by the present application, the third calculation module 23 is specifically further configured to:

[0127] The time difference between the current time and the last time and the battery cycle number difference between the current time and the last time are calculated.

[0128] The weight value of the current full-charge capacity value is calculated according to the time difference and the battery cycle number difference.

[0129] In an optional embodiment provided by the present application, the limiting module 24 is specifically configured to:

[0130] The battery cycle number of the target battery pack at the current time is obtained.

[0131] The lower limit battery health state of the target battery pack at the current time is determined according to the battery cycle number and a preset battery attenuation curve.

[0132] The lower limit battery health state at the current time is determined as the lower limit value of the limiting processing.

[0133] The specific limitation of the device can refer to the limitation of the battery health state determination method in the above, which will not be repeated here. Each module in the above device can be realized by software, hardware and their combination in whole or in part. The above modules can be embedded in or independent of the processor in the energy storage device in hardware form, or can be stored in the memory in the energy storage device in the form of software, so as to call and execute the operation corresponding to each module by the processor.

[0134] In an embodiment, an energy storage device is provided, which can be a server, and the internal structure diagram can be as shown in Figure 3The energy storage device includes a processor, a memory, a network interface and a database connected through a system bus. The processor of the energy storage device is configured to provide computing and control capabilities. The memory of the energy storage device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operating system and the computer program in the non-volatile storage medium to run. The network interface of the energy storage device is configured to communicate with an external terminal through a network connection. The computer program is executed by the processor to implement a method for determining a battery state of health.

[0135] In one embodiment, an energy storage device is provided, including a memory, a processor and a computer program stored in the memory and executable on the processor, the processor executing the computer program to implement the following steps:

[0136] When the target battery pack meets the full charge and full discharge condition, a full charge capacity value of the target battery pack at a current time is calculated by a full charge and full discharge method;

[0137] When the target battery pack meets the low-end full charge condition, a full charge capacity value of the target battery pack at a current time is calculated by a two-point method;

[0138] A real battery state of health value at the current time is calculated according to the full charge capacity value at the current time and a full charge capacity value at a previous time;

[0139] The real battery state of health value at the current time is subjected to a limiting process to obtain a display battery state of health value at the current time.

[0140] In one embodiment, a computer readable storage medium is provided, having a computer program stored thereon, the computer program being executed by a processor to implement the following steps:

[0141] When the target battery pack meets the full charge and full discharge condition, a full charge capacity value of the target battery pack at a current time is calculated by a full charge and full discharge method;

[0142] When the target battery pack meets the low-end full charge condition, a full charge capacity value of the target battery pack at a current time is calculated by a two-point method;

[0143] A real battery state of health value at the current time is calculated according to the full charge capacity value at the current time and a full charge capacity value at a previous time;

[0144] The real battery state of health value at the current time is subjected to a limiting process to obtain a display battery state of health value at the current time.

[0145] In one embodiment, a computer program product is provided, the computer program product including a computer program, the computer program being executed by a processor to implement the following steps:

[0146] calculating the full charge capacity value of the target battery pack at the current time point by the full charge and discharge method when the target battery pack meets the full charge and discharge condition;

[0147] calculating the full charge capacity value of the target battery pack at the current time point by the two-point method when the target battery pack meets the low-end full charge condition;

[0148] calculating the real battery health state value at the current time point according to the full charge capacity value at the current time point and the full charge capacity value at the last time point;

[0149] performing the limiting processing on the real battery health state value at the current time point to obtain the display battery health state value at the current time point.

[0150] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiments can be completed by a computer program instructing related hardware, and the computer program can be stored in a non-volatile computer readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments. Any reference to memory, storage, database or other medium used in the embodiments provided in the present application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM) and memory bus dynamic RAM (RDRAM) and the like.

[0151] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is exemplified, and in actual application, the above-mentioned functions can be completed by different functional units and modules according to needs, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above.

[0152] The above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced by equivalent features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A method of determining a state of health of a battery, the method comprising: The method comprises: When the target battery pack meets full-charge full-discharge conditions, calculating a full-charge capacity value of the target battery pack at a current time point by a full-charge full-discharge method; When the target battery pack meets low-end full-charge conditions, calculating the full-charge capacity value of the target battery pack at the current time point by a two-point method; Calculating a real battery health state value at the current time point according to the full-charge capacity value at the current time point and a full-charge capacity value at a previous time point; Limiting the real battery health state value at the current time point to obtain a display battery health state value at the current time point.

2. The method of claim 1, wherein, The full-charge capacity value of the target battery pack at the current time point is calculated by the two-point method, comprising: Obtaining an effective flag, a capacity retention rate, a first SOC value, and a second SOC value in a battery state of charge parameter, wherein the first SOC value is less than a preset percentage, and the second SOC value is an SOC value in a full-charge state; If the effective flag is valid, calculating the full-charge capacity value of the target battery pack at the current time point according to the capacity retention rate, the first SOC value, and the second SOC value.

3. The method of claim 2, wherein, The full-charge capacity value of the target battery pack at the current time point is calculated according to the capacity retention rate, the first SOC value, and the second SOC value, comprising: The full-charge capacity value of the target battery pack at the current time point is calculated by the following formula: wherein SOC Low is the first SOC value, DesignCap is the target battery pack's rated capacity, ΔCap is the target battery pack's capacity difference between the first SOC value and the second SOC value, RetenSoc is the capacity retention rate of the target battery pack under the current operating condition.

4. The method of claim 1, wherein, The full-charge capacity value of the target battery pack at the current time point is calculated by the full-charge full-discharge method, comprising: Obtaining a capacity retention rate, a second SOC value, and a third SOC value in a battery state of charge parameter, wherein the third SOC value is an SOC value in a full-discharge state, and the second SOC value is an SOC value in a full-charge state; Calculating the full-charge capacity value of the target battery pack at the current time point according to the capacity retention rate, the second SOC value, and the third SOC value.

5. The method of claim 4, wherein, The full-charge capacity value of the target battery pack at the current time point is calculated according to the capacity retention rate, the second SOC value, and the third SOC value, comprising: The full-charge capacity value of the target battery pack at the current time point is calculated by the following formula: wherein, ΔCap is a capacity difference of the target battery pack between the second SOC value and the third SOC value, RetenSoc FullDsg is a capacity retention rate of the target battery pack under current operating conditions, and DesignCap is a rated capacity of the target battery pack.

6. The method of claim 1, wherein, The real battery health state value at the current time point is calculated according to the full-charge capacity value at the current time point and the full-charge capacity value at the previous time point, comprising: Weighted calculation is performed on the full-charge capacity value at the current time point and the full-charge capacity value at the previous time point to obtain an effective full-charge capacity; Calculating a ratio of the effective full-charge capacity to a rated capacity of the target battery pack to obtain the real battery health state value at the current time point.

7. The method of claim 6, wherein, The method further comprises: Calculating a time difference between the current time point and the previous time point, and a battery cycle number difference between the current time point and the previous time point; According to the time difference and the battery cycle number difference, a weight value of the full-charge capacity value at the current time point is calculated.

8. The method according to any one of claims 1 to 6, characterized in that, The method further comprises: Obtaining a battery cycle number of the target battery pack at the current time point; According to the battery cycle number and a preset battery attenuation curve, a lower limit battery health state of the target battery pack at the current time point is determined; The lower limit battery health state at the current time point is determined as a lower limit value of the limiting processing.

9. An energy storage device, characterized by, Comprise: A processor, a memory, and a bus, the memory storing machine readable instructions executable by the processor, when the electronic device is running, the processor and the memory communicating through the bus, the machine readable instructions being executed by the processor to perform the steps of the method for determining the state of health of a battery according to any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that, A computer readable storage medium storing a computer program, the computer program being executed by a processor to perform the steps of the method for determining the state of health of a battery according to any one of claims 1 to 8.

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