Cloud full-time equalization capacity estimation method based on monomer voltage and electronic device

Abstract

The present invention discloses a cloud full-time equalization capacity estimation method and an electronic device based on monomer voltage, which relates to the technical field of battery dynamic management and control, and solves the technical problem that the passive equalization mode adopted in the prior art is limited by the thermal management ability of the equalization circuit, resulting in difficulty in achieving deep equalization within a limited time window. The present invention constructs a charging voltage curve by obtaining the charging start time, end time, voltage values and current values at different moments during the charging process of the energy storage battery pack; determines whether the voltage conditions and stable current duration of the corresponding monomers are both qualified; determines whether the remaining capacities of the corresponding monomers before and after charging are consistent; calculates the voltage difference of the monomers before and after charging, and preliminarily screens the equalization monomer list based on the voltage difference; obtains the equalization battery capacity of the monomers based on the starting moment for the list; determines an equalization scheme according to the equalization battery capacity and the equalization monomer list; the present invention improves the equalization effect and the stability of the energy storage system.

Description

Technical Field

[0001] The present invention belongs to the field of battery dynamic control, relates to battery equalization technology, and specifically is a cloud full-time equalization capacity estimation method and an electronic device based on single-cell voltage. Background Art

[0002] Energy storage battery packs are the basic components of energy storage systems. To meet a certain voltage level, a large number of monomers are usually connected in series for combination; in actual application scenarios, due to the factor of the series structure of monomers, combined with the natural differences in manufacturing processes, material characteristics, etc. of each monomer, as well as self-discharge differences, even when in the same charge-discharge environment, the charging or discharging time of monomers to full charge or full discharge will be different. Therefore, after a period of use, the state of charge between monomers becomes inconsistent, which is intuitively manifested as the voltage of some monomers being relatively high while the voltage of other monomers is relatively low, bringing negative impacts to the performance stability and efficient operation of the entire energy storage system.

[0003] Regarding the consistency differences of monomers in the energy storage battery pack, the application of equalization technology is crucial; currently, the commonly used passive equalization means in the prior art are mostly implemented at the end stage of battery charging. At this stage, the relationship between battery voltage and battery state of charge is relatively obvious. The prior art uses a voltage difference detection mechanism to identify the voltage differences between battery monomers and discharge-equalize the high-voltage monomers; however, it does not consider that the passive equalization mode is limited by the power density and thermal management capabilities of the equalization circuit, resulting in problems such as low equalization efficiency, large energy loss, and difficulty in achieving deep equalization within a limited time window.

[0004] At the same time, due to the limited computing power and storage resources of the embedded controller in the prior art, it is difficult for the system to build an accurate battery model and perform real-time health status assessment, resulting in the inability to accurately estimate the differential equalization capacity required for each monomer through dynamic parameter identification, and thus unable to eliminate the virtual voltage phenomenon caused by the polarization characteristic differences of monomers and difficult to achieve global optimization of the energy utilization efficiency of the battery pack.

[0005] The present invention provides a cloud full-time equalization capacity estimation method and an electronic device based on single-cell voltage to solve the above technical problems. Summary of the Invention

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art; for this purpose, the present invention proposes a cloud full-time equalization capacity estimation method and an electronic device based on single-cell voltage to solve the technical problem that the passive equalization mode adopted in the prior art is limited by the power density and thermal management capabilities of the equalization circuit, resulting in difficulty in achieving deep equalization within a limited time window.

[0007] To achieve the above object, a first aspect of the present invention provides a cloud full-time equalization capacity estimation method based on monomer voltage, including:

[0008] S100: Obtain the charging start time, end time, voltage values and current values at different moments during the charging process of the energy storage battery pack, and construct a charging voltage curve;

[0009] S200: For each monomer in the energy storage battery pack, when the voltage condition and the stable current duration of the monomer are both qualified, obtain the remaining capacity of the monomer before and after charging;

[0010] S300: Determine whether the remaining capacity of the monomer before and after charging is consistent; if yes, calculate the voltage difference of the monomer before and after charging, and initially screen the equalization monomer list based on the voltage difference; if not, output a label indicating that the remaining capacity of the monomer is inconsistent;

[0011] S400: If the remaining capacity of the monomers in the energy storage battery pack before and after charging is consistent, obtain a list of starting moments for the translation of the charging voltage curve; obtain the equalization battery capacity of the monomer based on the list of starting moments; determine an equalization scheme according to the equalization battery capacity and the equalization monomer list.

[0012] Preferably, before obtaining the remaining capacity of the monomer before and after charging when the voltage condition and the stable current duration of the monomer are both qualified, it further includes:

[0013] The specific steps for determining whether the voltage condition of the monomer is qualified include:

[0014] S210: Generate a sampling time set T = {1, 2, 3,..., n} based on the charging start time and end time of the energy storage battery pack; mark the set of voltage conditions of the monomers in all energy storage battery packs at several moments as; where n represents the number of sampling times; represents the voltage set of all monomers at the t-th moment; is the voltage of the i-th monomer corresponding to the t-th moment, and the monomer set I of the energy storage battery pack = {1, 2, 3,..., m}, and m represents the number of monomers;

[0015] S211: Mark the minimum value among all monomer voltages corresponding to the first moment as the starting minimum voltage;

[0016] S212: Mark the maximum value among all monomer voltages corresponding to the n-th moment as the ending maximum voltage;

[0017] S213: If the starting minimum voltage is less than or equal to a preset voltage lower limit threshold and the ending maximum voltage is greater than or equal to a preset voltage upper limit threshold, determine that the voltage condition of the monomer is qualified.

[0018] Preferably, before obtaining the remaining capacity of the monomer before and after charging when the voltage condition and the stable current duration of the monomer are both qualified, the following steps are further included:

[0019] The specific steps for determining whether the stable current duration of the monomer is qualified include:

[0020] S220: Divide the difference between the current at the current moment and the current at the previous moment by the current at the previous moment to obtain the current fluctuation ratio value at the current moment ; Construct a fluctuation ratio list through the current fluctuation ratio value ;

[0021] S221: Obtain the current segment endpoint list through the expression ;

[0022] S222: Calculate the maximum time difference between adjacent endpoints in the current segment endpoint list through the formula ; where, is the preset sampling time interval; represents the t-th element in the current segment endpoint list ST, and L represents the number of elements in the current segment endpoint list ST;

[0023] S223: Determine whether the maximum time difference is less than the preset time length threshold; if yes, mark the stable current duration of the monomer as unqualified; if no, mark the stable current duration of the monomer as qualified.

[0024] It should be noted that the charging time of the energy storage from SOC = 0% to SOC = 100% at night is 5 hours, so the preset time length threshold is less than 5 hours.

[0025] By setting the time length threshold in the present invention, it is beneficial to make the observed stable current time during charging as long as possible; since the drastic change of the current will cause the drastic change of the voltage, by determining whether the maximum time difference is less than the preset time length threshold to obtain the stable current duration that meets the conditions, it is beneficial to obtain a relatively reasonable result by implementing curve translation subsequently.

[0026] Preferably, determining whether the remaining capacity of the monomer before and after charging is consistent includes:

[0027] S310: Obtain the minimum voltage monomer and the maximum voltage monomer at each moment during charging and number the monomers; Mark the monomer number that appears most frequently in the minimum voltage monomers as monomer x, and mark the monomer number that appears most frequently in the maximum voltage monomers as monomer y; where, the minimum voltage monomer refers to the monomer corresponding to the minimum value among all monomer sampling voltages at each moment, and the maximum voltage monomer refers to the monomer corresponding to the maximum value among all monomer sampling voltages at each moment;

[0028] S311: Preset a set of conditions, determine whether the remaining capacity of the cell does not meet the set of conditions; if so, mark the remaining capacity of the cell before and after charging as consistent;

[0029] If not, the remaining capacity of the monomer before and after charging is marked as inconsistent; wherein the preset condition set includes: preset condition 1, preset condition 2, and preset condition 3;

[0030] The first preset condition is: cell x is the cell with the highest voltage at the end of charging;

[0031] The second preset condition is: cell y is the cell with the lowest voltage at the end of charging;

[0032] The third preset condition is that the monomer with the smallest starting voltage is consistent with the monomer with the largest ending voltage.

[0033] In the present invention, if the remaining capacity of the cells is consistent and the charging current of all cells in series is the same, then the amount of electricity charged is the same, and the voltage change should also be basically the same, so the cell voltage performance after charging is consistent with before; if it is determined that the remaining capacity of the cell voltage meets the condition set, it is considered that there is a certain inconsistency in the remaining capacity between the cells. At this time, the cell is not suitable for balancing processing to a certain extent, and subsequent calculations are not performed to avoid unnecessary energy consumption and potential damage to the battery, thereby improving system efficiency and extending the life of the battery pack.

[0034] Preferably, the initial screening of the balancing monomer list based on the voltage difference includes:

[0035] S320: Retrieve cell a and the minimum starting voltage corresponding to cell a ; Among them, monomer a is the monomer corresponding to the minimum starting voltage;

[0036] S321: By formula Calculate the voltage difference between the i-th cell and cell a at the start time; where, Indicates the voltage value corresponding to the i-th cell at the starting moment;

[0037] S322: Statistical voltage difference A list of cells g whose voltage difference is greater than a preset starting voltage threshold;

[0038] S323: By formula Calculate the voltage difference between the ith cell and cell a at the end time; where, Indicates the voltage value corresponding to the i-th cell at the end time;

[0039] S324: Statistical voltage difference The list h of cells with a voltage difference greater than the preset end voltage difference threshold; let the union of lists g and h be the list f of cells to be balanced;

[0040] Determine whether the list f of cells to be balanced is empty; if yes, output the label indicating that the cell consistency does not require balancing; if no, mark it as the initial screening of the balanced cell list is completed.

[0041] In the present invention, the relationship between the remaining power and voltage of cells within a period at the start and end of charging is relatively obvious. The cell with a larger voltage has more remaining power. Therefore, to a certain extent, the voltage difference reflects the size of the capacity difference; by counting the list of cells with a voltage difference greater than the preset end voltage difference threshold, that is, selecting cells with a large voltage difference for calculation and balancing, it is beneficial to reduce part of the calculation amount.

[0042] Preferably, the obtaining of the starting time pair list for translating the charging voltage curve includes:

[0043] S410: Mark the cell with the minimum voltage at the end of charging as cell b;

[0044] S411: Retrieve the balanced cell list after initial screening and traverse the list of cells to be balanced. Mark the currently calculated cell as cell k, and use the charging voltage curve of cell k as the reference charging voltage curve; mark the starting time of the reference charging voltage curve segment selected by cell k as s_k; through the function Calculate the starting time of the segment with the maximum similarity corresponding to cell b, where, represents the Manhattan distance between cell b at the set time one and cell k at the set time two, and l_k represents the length of the reference charging voltage curve segment selected by cell k;

[0045] S412: Mark the starting time pair of the translated reference charging voltage curve as (s_k, s_b);

[0046] S413: Select the first P1% of the voltage data of cell k as the reference charging voltage curve segment k1, mark the starting time of k1 as s_k1, and select all the voltage data of cell b as the charging voltage curve b1 to be translated; where 0 < P1 < 50;

[0047] S414: Traverse all the times of the charging voltage curve b1 to be translated. Let the currently traversed time be s1. Select a data segment with the same length as the reference charging voltage curve segment k1 starting from the current time s1, calculate the Manhattan distance from the reference curve segment k1, and select the starting time with the minimum Manhattan distance, denoted as s1_b1; then mark the starting time pair of the charging voltage curve b1 to be translated as (s1_k1, s1_b1);

[0048] S415: Select the data of monomer k from P1% to P2% as the reference charging voltage curve segment k2, and set the starting time of k2 as s2_k2. Select all voltage data of monomer b as the charging voltage curve b2 to be translated; where P1 < P2 < 100;

[0049] S416: Traverse all the times of the charging voltage curve b2 to be translated. Let the currently traversed time be s2. Select the data with the same length as the reference charging voltage curve segment k2 starting from s2, and calculate the Manhattan distance from the reference charging voltage curve segment k2. Select the starting time with the smallest Manhattan distance and denote it as s2_b2. Obtain the starting time pair (s2_k2, s2_b2);

[0050] S417: Then the starting time pair list is {(s1_k1, s1_b1), (s2_k2, s2_b2)}.

[0051] Through the P1 - P2 segmentation strategy, the present invention decomposes and independently analyzes the charging voltage curve, reducing the cumulative error caused by overall translation.

[0052] Preferably, the method for obtaining the Manhattan distance includes:

[0053] Manhattan distance Obtaining method: ; In the formula, represents the length of the reference charging voltage curve segment k1, represents the voltage of monomer k at time represents the voltage of monomer b at time represents the counting subscript of the voltage sampling time corresponding to the reference curve segment k1.

[0054] Preferably, the method for obtaining the balanced battery capacity of the monomer based on the starting time pair list includes:

[0055] S420: Retrieve the starting time pair list, and obtain the charging current value between the starting time pairs (s1_k1, s1_b1) in the starting time pair list. Calculate the battery capacity capacity1 according to the ampere - hour integration method;

[0056] Obtain the charging current value between the starting time pairs (s2_k2, s2_b2) in the starting time pair list, and calculate the battery capacity capacity2 according to the ampere - hour integration method;

[0057] S421: Take the average value of the battery capacities of the two time pairs as the balanced battery capacity of the monomer;

[0058] S422: Repeat steps S410 - S417 and steps S420 - S421 to calculate the balanced battery capacity of all monomers to be balanced compared with monomer b.

[0059] Preferably, determining the balancing scheme according to the balanced battery capacity and the balanced monomer list includes:

[0060] Construct the execution limit of the battery management system BMS, where the BMS execution limit includes: the balanced battery capacity can at most turn on half of all monomers, and the corresponding balanced monomers cannot be adjacent;

[0061] Based on the BMS execution limit, sort the balanced monomers corresponding to the balanced battery capacity in descending order, construct and initialize the final balanced list to be empty, and sequentially traverse all the sorted balanced monomers;

[0062] Judge whether there is a monomer adjacent to the currently traversed monomer in the final balanced list; if yes, skip the currently traversed monomer; if no, add the currently traversed monomer to the final balanced list; until the number of balanced monomers is greater than the limit number or the sorted balanced monomer list is traversed, output the final balanced monomer list and the corresponding balanced capacity as the balancing scheme, and end the algorithm;

[0063] The BMS performs actual balancing operations according to the balancing scheme.

[0064] It should be noted that when performing passive balancing heat dissipation, a resistor or an equivalent energy-consuming component is connected in parallel to each monomer, and the switch is controlled to form a loop between the monomer and the corresponding parallel resistor, which is beneficial for the monomer to discharge through the resistor and dissipate the excess energy in the form of heat, resulting in excessive heat generation of the resistor and triggering other battery failures. By setting the BMS execution limit in this application, the resistor discharge can be effectively restricted, thereby avoiding other battery failures caused by excessive heat generation of the resistor.

[0065] To achieve the above object, the second aspect of the present invention provides an electronic device for estimating the full-time balanced capacity of the cloud based on the monomer voltage, including: a memory and a processor, and the memory stores executable instructions of the processor; wherein, the processor is configured to execute the full-time balanced capacity estimation of the cloud based on the monomer voltage provided in the first aspect by executing the executable instructions.

[0066] Compared with the prior art, the beneficial effects of the present invention are:

[0067] 1. By using the charging voltage data uploaded in real time by the energy storage battery pack, the present invention migrates complex calculation tasks to the cloud for processing. Relying on the powerful computing power and sufficient storage resources of the cloud, combined with the voltage curve translation method, the equalization capacity of single cells can be calculated quickly and efficiently. In this way, the limitations of traditional passive equalization are broken, providing strong technical support for realizing the full-time equalization management of the energy storage battery pack and extending its service life. Relying on the strong adaptability of the cloud, based on the charging voltage data of the energy storage battery pack, by deeply analyzing dynamic changes such as voltage curve translation, appropriate equalization strategies can be set according to energy storage devices of different specifications and different application scenarios, achieving relatively good versatility and compatibility. In addition, the cloud computing of the equalization capacity also has good scalability. As the scale of the energy storage battery pack continues to expand and the application scenarios become increasingly diverse, the cloud can easily handle the growth of data volume and the increase in calculation complexity, always ensuring the accuracy and timeliness of the equalization capacity calculation.

[0068] 2. The present invention deeply analyzes the charging voltage data of the lithium iron phosphate energy storage battery pack through the cloud, accurately captures the offset time based on voltage curve translation between single cells, and further calculates the equalization capacity in combination with current information. This method considers multi-dimensional information such as the voltage change trend and time during the charging process of single cells, can relatively accurately measure the true capacity difference between single cells, making the calculated equalization capacity meet the actual needs and providing a reliable basis for subsequent equalization operations. The present invention analyzes the charging voltage data and the corresponding equalization calculation logic through the cloud, breaking the time limit of traditional passive equalization and realizing the full-time equalization management of the energy storage battery pack. With the real-time and uninterrupted operation characteristics of the cloud, regardless of whether the energy storage is in the charging, discharging or static state, equalization operations can be carried out in a timely manner according to the calculated equalization capacity, effectively maintaining the consistency between single cells, improving the equalization effect as a whole, and ensuring the more stable and efficient operation of the energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0070] Figure 1 It is a schematic flow chart of a method for estimating the full-time equalization capacity of single cell voltages provided by the present invention;

[0071] Figure 2 It is a schematic diagram of the specific steps of another method for estimating the full-time equalization capacity of single cell voltages provided by the present invention;

[0072] Figure 3 Schematic diagram of the translation result of the voltage curve of the present invention;

[0073] Figure 4 Schematic diagram of the specific steps of another method for estimating the full-time equalization capacity of the monomer voltage provided by the present invention. Specific embodiments

[0074] The technical solutions of the present invention will be described clearly and completely below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts belong to the scope of protection of the present invention.

[0075] Please refer to Figure 1 , an embodiment of the first aspect of the present invention provides a method for estimating the full-time equalization capacity of the cloud based on the monomer voltage, including:

[0076] S100: Obtain the charging start time, end time, voltage values and current values at different times during the charging process of the energy storage battery pack, and construct a charging voltage curve;

[0077] S200: For each monomer in the energy storage battery pack, when the voltage condition and the stable current duration of the monomer are both qualified, obtain the remaining capacity of the monomer before and after charging;

[0078] S300: Determine whether the remaining capacity of the corresponding monomer before and after charging is consistent; if so, calculate the voltage difference of the monomer before and after charging, and initially screen the equalization monomer list based on the voltage difference; if not, output a label indicating that the remaining capacity of the corresponding monomer is inconsistent;

[0079] S400: If the remaining capacity of the monomers in the energy storage battery pack before and after charging is consistent, obtain the starting time pair list for the translation of the charging voltage curve; obtain the equalization battery capacity of the corresponding monomer based on the starting time pair list; determine the equalization scheme according to the equalization battery capacity and the equalization monomer list.

[0080] Please refer to Figure 2 , the solution described in the above S200 can be specifically implemented through the following steps S210-S213 and steps S220-S223. Among them, S210-S213 are used to determine whether the voltage condition of the monomer is qualified, and S220-S223 are used to determine whether the stable current duration of the monomer is qualified.

[0081] First, the process of determining whether the voltage condition of the monomer is qualified will be described in combination with the following S210-S213:

[0082] S210: Generate a sampling time set T = {1, 2, 3, …, n} based on the start time and end time of charging the energy storage battery pack; mark the set of the voltages of the monomers in all energy storage battery packs at several moments as ; where n represents the number of sampling times; represents the voltage set of all monomers at the t-th moment; is the voltage of the i-th monomer corresponding to the t-th moment, and the monomer set I of the energy storage battery pack = {1, 2, 3, …, m}, where m represents the number of monomers;

[0083] S211: Mark the minimum value among all monomer voltages corresponding to the first moment as the starting minimum voltage;

[0084] S212: Mark the maximum value among all monomer voltages corresponding to the n-th moment as the ending maximum voltage;

[0085] S213: If the starting minimum voltage is less than or equal to the preset voltage lower limit threshold and the ending maximum voltage is greater than or equal to the preset voltage upper limit threshold, determine that the voltage condition of the monomer is qualified;

[0086] Secondly, the process of judging whether the stable current duration of the monomer is qualified is described in combination with the following S220 - S223:

[0087] S220: Divide the difference between the current at the current moment and the current at the previous moment by the current at the previous moment to obtain the current fluctuation ratio value at the current moment ; construct a fluctuation ratio list through the current fluctuation ratio value ;

[0088] S221: Obtain the current segment endpoint list through the expression ;

[0089] S222: Calculate the maximum time difference between adjacent endpoints in the current segment endpoint list through the formula ; where is the preset sampling time interval; represents the t-th element in the current segment endpoint list ST, and L represents the number of elements in the current segment endpoint list ST;

[0090] S223: Judge whether the maximum time difference is less than the preset time length threshold; if so, mark the stable current duration of the corresponding monomer as unqualified; otherwise, mark the stable current duration of the corresponding monomer as qualified.

[0091] For example, there is an energy storage battery pack being charged. The energy storage terminal accurately records the charging start and end times based on its own data platform and generates a sampling time set based on this. ; Through the established stable communication link with the cloud, these key time information are transmitted to the cloud; after receiving the relevant instructions, the cloud accurately extracts the data of the current charging segment of the energy storage battery pack from the massive data and completely transmits it into the cloud environment for subsequent processing; these data cover the voltage conditions of all single cells at each moment, denoted as ;

[0092] By processing the voltages of the single cells sampled at the start time and the end time through the cloud, the minimum voltage at the start is calculated and its corresponding single cell a and the maximum voltage at the end ; Set the voltage lower limit threshold to 3200 millivolts and the voltage upper limit threshold to 3450 millivolts;

[0093] Now, the minimum voltage at the start of the lithium iron phosphate single cells in all energy storage battery packs is less than the voltage lower limit threshold, and the maximum voltage at the end is greater than the voltage upper limit threshold;

[0094] Through the cloud, calculate the fluctuation ratio values of all adjacent currents, and preset the current fluctuation threshold to 10%;

[0095] If the current fluctuation ratio at the current moment is greater than 10%, it is considered that a significant current fluctuation has occurred from the previous moment to the current moment. At this time, the two data points corresponding to the current moment and the previous moment are divided into different segments, that is, the current moment is the start time of a new segment; find the moments with fluctuation ratio values greater than the current fluctuation threshold in all segments to form a current segment endpoint list, add the start time and the end time to the head and tail of the current segment endpoint list respectively, and through the formula calculate the maximum time difference between adjacent endpoints in the current segment endpoint list; if the maximum time difference at this moment is greater than the preset time length threshold of 3 hours; then mark the stable current duration of the corresponding single cell as qualified.

[0096] It should be noted that since there is no current at the previous moment for the first data point, it is supplemented to the current segment endpoint list; the end time is supplemented to calculate the duration of the last segment.

[0097] Please refer to Figure 4 , for the specific steps of another method for estimating the full-time equalization capacity of the single cell voltage in the cloud:

[0098] S410: Mark the single cell with the minimum voltage at the end of charging as single cell b;

[0099] S411: Retrieve the list of equalization single cells after preliminary screening and traverse the list to be equalized. Mark the single cell to be calculated currently as single cell k, and use the charging voltage curve of single cell k as the reference charging voltage curve; mark the start time of the reference charging voltage curve segment selected by single cell k as s_k; through the function Calculate the starting time of the fragment with the maximum similarity corresponding to monomer b, where represents the Manhattan distance between monomer b corresponding to the set time 1 and monomer k corresponding to the set time 2, and \(l_k\) represents the length of the reference charging voltage curve fragment selected by monomer k;

[0100] S412: Mark the starting time pair of the translated reference charging voltage curve as \((s_k, s_b)\);

[0101] S413: Select the first P1% of the voltage data of monomer k as the reference charging voltage curve fragment k1, mark the starting time of k1 as \(s_{k1}\), and select all the voltage data of monomer b as the charging voltage curve b1 to be translated; where \(0 < P1 < 50\);

[0102] S414: Traverse all the times of the charging voltage curve b1 to be translated, let the current traversed time be \(s1\), select the data fragment with the same length as the reference charging voltage curve fragment k1 starting from the current time \(s1\), calculate the Manhattan distance from the reference curve fragment k1, and select the starting time with the smallest Manhattan distance, denoted as \(s1_{b1}\); then mark the translation starting time pair of the charging voltage curve b1 to be translated as \((s1_{k1}, s1_{b1})\);

[0103] Manhattan distance Obtaining method: ; In the formula, represents the length of the reference charging voltage curve fragment k1, represents the voltage of monomer k at time represents the voltage of monomer b at time represents the counting subscript of the voltage sampling time corresponding to the reference curve fragment k1;

[0104] S415: Select the data of monomer k from P1% to P2% as the reference charging voltage curve fragment k2, the starting time of k2 is \(s2_{k2}\), and select all the voltage data of monomer b as the charging voltage curve b2 to be translated; where \(P1 < P2 < 100\);

[0105] S416: Traverse all the times of the charging voltage curve b2 to be translated, let the current traversed time be \(s2\), select the data with the same length as the reference charging voltage curve fragment k2 starting from \(s2\), and calculate the Manhattan distance from the reference charging voltage curve fragment k2; select the starting time with the smallest Manhattan distance, denoted as \(s2_{b2}\); obtain the starting time pair \((s2_{k2}, s2_{b2})\);

[0106] S417: The starting time pair list is {(s1_k1, s1_b1), (s2_k2, s2_b2)};

[0107] S420: Retrieve the starting time pair list, and obtain the charging current value between the starting time pairs (s1_k1, s1_b1) in the starting time pair list. Calculate the battery capacity capacity1 according to the ampere-hour integration method;

[0108] Obtain the charging current value between the starting time pairs (s2_k2, s2_b2) in the starting time pair list. Calculate the battery capacity capacity2 according to the ampere-hour integration method;

[0109] S421: Take the average value of the battery capacities of the two time pairs as the balanced battery capacity of the corresponding single cell;

[0110] S422: Repeat steps S410 - S417 and steps S420 - S421 to calculate the balanced battery capacity of all the single cells to be balanced compared with single cell b; Take the final balanced single cell list and the corresponding balanced capacity as the balancing scheme.

[0111] For example, select the voltage data of the first 33% of single cell k as the reference curve segment k1, record its starting time as s_k1, and select all the voltage data of single cell b as the curve b1 to be translated;

[0112] Traverse all the times of the curve b1 to be translated. Let the currently traversed time be s. Select the data segment with the same length as the reference curve segment k1 starting from s, calculate the Manhattan distance from the reference curve segment k1, and record the starting time s and the corresponding Manhattan distance; Select the starting time with the smallest Manhattan distance and record it as s_b1; Obtain the starting time pair (s_k1, s_b1); As Figure 3 shown in Figure (a), the blue solid line represents the reference curve, and the yellow dashed line represents the curve b1 to be translated; The part between the red crosses in the blue solid line represents the reference curve segment k1, and the part between the red stars in the yellow dashed line represents the part with the smallest Manhattan distance obtained by traversing the curve to be translated, which is recorded as the translation segment; The sub - figure in the lower right corner is the translation schematic diagram of these two parts. The green dotted line represents the translated curve drawn according to the translation segment. It can be seen that the blue solid line and the green dotted line in the sub - figure have a high degree of coincidence, indicating that the reference curve segment k1 and the translation segment have a high degree of similarity; Record the starting times of the two to form a starting time pair;

[0113] Select the data of single cell k from 33% to 66% as the reference curve segment k2, record its starting time as s_k2, and select all the voltage data of single cell b as the curve b2 to be translated;

[0114] Similarly, traverse all moments of the curve b2 to be translated. Let the currently traversed moment be s. Select the data with the same length as the reference curve segment k2 starting from s, and calculate the Manhattan distance from the reference curve segment k2. The two voltage curves are translated left and right in time. Here, the curve b2 to be translated needs to be shifted to the left to approximately coincide with the reference curve segment k2. Therefore, we can directly start traversing from s_k2 and discard the part before s_k2 to reduce the amount of calculation. Select the starting moment with the smallest Manhattan distance and denote it as s_b2. Obtain the starting moment pair (s_k2, s_b2). As Figure 3 As shown in Figure (b) of Figure 3 , similarly, the blue solid line represents the reference curve, and the yellow dashed line represents the curve b2 to be translated. The part between the red crosses in the blue solid line represents the reference curve segment k2, and the part between the red stars in the yellow dashed line represents the part with the smallest Manhattan distance obtained by traversing the curve to be translated, denoted as the translation segment. The subgraph in the lower right corner is the translation schematic diagram of these two parts. The green dotted line represents the translated curve drawn according to the translation segment. It can be seen that the blue solid line and the green dotted line in the subgraph have a high degree of coincidence, indicating that the reference curve segment k2 and the translation segment have a high degree of similarity. Record the starting moments of the two to form the starting moment pair;

[0115] Thus, the obtained starting moment pair list is {(s_k1, s_b1), (s_k2, s_b2)};

[0116] Obtain the current data between the moment pair (s_k1, s_b1), and calculate the capacity according to the ampere-hour integration method: calculate the difference list between adjacent moments, calculate the average current list between adjacent moments, multiply the moment difference list and the average current list one by one and then sum, and convert the unit to ampere-hour. That is, the balanced capacity calculated for this moment pair is denoted as capacity1; similarly, calculate the balanced capacity of the moment pair (s_k2, s_b2) and denote it as capacity2; take the average of the calculation results of the two moment pairs (capacity1 + capacity1) / 2 as the balanced capacity of this single cell; Take the final balanced single cell list and the corresponding balanced capacity as the balanced scheme.

[0117] The second aspect of the present invention provides an electronic device for estimating the full-time balanced capacity of the cloud based on the single-cell voltage, including: a memory and a processor, and the memory stores executable instructions of the processor; wherein, the processor is configured to execute the executable instructions to implement the estimation of the full-time balanced capacity of the cloud based on the single-cell voltage provided in the first aspect.

[0118] Some of the data in the above formula are calculated by removing the dimension and taking its numerical value. The formula is the one closest to the actual situation obtained by software simulation of a large amount of collected data; the preset parameters and preset thresholds in the formula are set by those skilled in the art according to the actual situation or obtained by simulating a large amount of data.

[0119] Working principle of the present invention: The present invention obtains the charging start time, end time, voltage values and current values at different moments during the charging process of the energy storage battery pack, and constructs a charging voltage curve; obtains the voltage conditions of the single cells in the energy storage battery pack and determines whether the voltage conditions of the corresponding single cells are qualified; determines whether the stable current duration of the corresponding single cell is qualified; obtains the remaining capacity of the single cell before and after charging; determines whether the remaining capacity of the corresponding single cell before and after charging is consistent; if so, calculates the voltage difference of the single cell before and after charging, and initially screens the list of balanced single cells based on the voltage difference; if not, outputs a label indicating that there is an inconsistency in the remaining capacity of the corresponding single cell; if the remaining capacity of the single cells in the energy storage battery pack before and after charging is consistent, obtains the starting moment pair list for the translation of the charging voltage curve; obtains the balanced battery capacity of the corresponding single cell based on the starting moment pair list; and determines a balancing scheme according to the balanced battery capacity and the list of balanced single cells.

[0120] The above embodiments are only used to illustrate the technical method of the present invention and not to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical method of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical method of the present invention.

Claims

1. A cloud full-time equalization capacity estimation method based on monomer voltage, characterized in that Including: S100: Obtain the charging start time, end time, voltage values and current values at different moments during the charging process of the energy storage battery pack, and construct a charging voltage curve; S200: For each single cell in the energy storage battery pack, when the voltage condition and the stable current duration of the single cell are both qualified, obtain the remaining capacity of the single cell before and after charging; S300: Judge whether the remaining capacity of the single cell before and after charging is consistent; If yes, calculate the voltage difference of the single cell before and after charging, and initially screen the balanced single cell list based on the voltage difference; If no, output the label indicating that the remaining capacity of the single cell is inconsistent; S400: If the remaining capacity of the single cells in the energy storage battery pack before and after charging is consistent, obtain the starting moment pair list for the translation of the charging voltage curve; obtain the balanced battery capacity of the single cell based on the starting moment pair list; Determine the balancing scheme according to the balanced battery capacity and the balanced single cell list; The judgment of whether the remaining capacity of the single cell before and after charging is consistent includes: S310: Obtain the minimum voltage single cell and the maximum voltage single cell at each moment during the charging process and number the single cells; mark the single cell number that appears most frequently among the minimum voltage single cells as single cell x, and mark the single cell number that appears most frequently among the maximum voltage single cells as single cell y; among them, the minimum voltage single cell refers to the single cell corresponding to the minimum value among all single cell sampling voltages at each moment, and the maximum voltage single cell refers to the single cell corresponding to the maximum value among all single cell sampling voltages at each moment; S311: Preset a set of conditions, and judge whether the remaining capacity of the single cells all do not meet the set of conditions; if yes, mark the remaining capacity of the single cell before and after charging as consistent; If no, mark the remaining capacity of the single cell before and after charging as inconsistent; among them, the preset set of conditions includes: preset condition one, preset condition two and preset condition three; The preset condition one is: single cell x is the maximum voltage single cell at the end of charging; The preset condition two is: single cell y is the minimum voltage single cell at the end of charging; The preset condition three is: the single cell with the minimum starting voltage is the same as the single cell with the maximum ending voltage.

2. The method for estimating the full-time equalization capacity of the cloud based on the monomer voltage according to claim 1, wherein Before obtaining the remaining capacity of the single cell before and after charging when the voltage condition and the stable current duration of the single cell are both qualified, it further includes: The specific steps for judging whether the voltage condition of the single cell is qualified include: S210: Generate a sampling time set \(T = \{1, 2, 3, \ldots, n\}\) based on the start time and end time of charging of the energy storage battery pack; mark the set of voltages of the monomers in all energy storage battery packs at several moments as ; where \(n\) represents the number of sampling times; represents the voltage set of all monomers at the \(t\)-th moment; is the voltage of the \(i\)-th monomer corresponding to the \(t\)-th moment, and the monomer set of the energy storage battery pack is \(I = \{1, 2, 3, \ldots, m\}\), where \(m\) represents the number of monomers; S211: Mark the minimum value among all single cell voltages corresponding to the first moment as the starting minimum voltage; S212: Mark the maximum value among all single cell voltages corresponding to the nth moment as the ending maximum voltage; S213: If the starting minimum voltage is less than or equal to the preset voltage lower limit threshold and the ending maximum voltage is greater than or equal to the preset voltage upper limit threshold, determine that the voltage condition of the single cell is qualified.

3. The method for estimating the full-time equalization capacity of the cloud based on the monomer voltage according to claim 1, wherein Before obtaining the remaining capacity of the single cell before and after charging when the voltage condition and the stable current duration of the single cell are both qualified, it further includes: The specific steps for judging whether the stable current duration of the single cell is qualified include: S220: Obtain the current current fluctuation ratio value by dividing the difference between the current moment current and the previous moment current by the previous moment current ; Construct a fluctuation ratio list based on the current fluctuation ratio value ; S221: Find the moments corresponding to the current fluctuation ratio values greater than the preset current fluctuation threshold in all the fluctuation ratio lists to form a current segment endpoint list, and add the preset start time and end time to the head and tail of the current segment endpoint list respectively; S222: Calculate the maximum time difference between adjacent endpoints in the current segment endpoint list through the formula ; where, is the preset sampling time interval; represents the t-th element in the current segment endpoint list ST, and L represents the number of elements in the current segment endpoint list ST; S223: Determine whether the maximum time difference is less than the preset time length threshold; if yes, mark the stable current duration of the monomer as unqualified; if not, mark the stable current duration of the monomer as qualified.

4. The method for estimating the full-time equalization capacity of the cloud based on the monomer voltage according to claim 2, wherein The initial screening of the equalization monomer list based on the voltage difference includes: S320: Retrieve monomer a and the corresponding starting minimum voltage of monomer a ; wherein, monomer a is the monomer corresponding to the starting minimum voltage S321: Calculate the voltage difference between the i-th monomer and monomer a at the start time through the formula ; in the formula, represents the voltage value corresponding to the i-th monomer at the start time; S322: Statistic voltage difference The list g of monomers greater than the preset start voltage difference threshold; S323: Calculate the voltage difference between the i-th monomer and monomer a at the end time through the formula ; in the formula, represents the voltage value corresponding to the i-th monomer at the end time; S324: Statistic voltage difference in the list h of monomers greater than the preset end voltage difference threshold; let the union of lists g and h be the list f of monomers to be balanced; Judge whether the list f to be equalized is empty; if yes, output the label that the monomer consistency does not need to be equalized; if not, mark it as the completion of the initial screening of the equalization monomer list.

5. The method for estimating the full-time equalization capacity of the cloud based on the monomer voltage according to claim 1, wherein The obtaining of the list of starting moments for the translation of the charging voltage curve includes: S410: Mark the monomer with the minimum voltage at the end of charging as monomer b; S411: Retrieve the balanced monomer list after preliminary screening and traverse the list to be balanced. Mark the monomer to be calculated currently as monomer k, and use the charging voltage curve of monomer k as the reference charging voltage curve; mark the start time of the reference charging voltage curve segment selected by monomer k as s_k; through the function Calculate the start time of the segment with the maximum similarity corresponding to monomer b, where represents the Manhattan distance between monomer b at the set time one and monomer k at the set time two, and l_k represents the length of the reference charging voltage curve segment selected by monomer k; S412: Mark the starting moment pair of the translation of the reference charging voltage curve as (s_k, s_b); obtain the list of starting moment pairs through the starting moment pairs.

6. The method for estimating the full-time balancing capacity of the cloud based on the monomer voltage according to claim 5, wherein The obtaining method of the Manhattan distance includes: Manhattan distance Obtaining method: ; In the formula, represents the length of the reference charging voltage curve segment k1, represents the voltage of the kth monomer at time represents the voltage of the bth monomer at time represents the counting subscript of the voltage sampling time corresponding to the reference curve segment k1.

7. The method for estimating the cloud full-time equalization capacity based on the monomer voltage according to claim 5, wherein The obtaining of the equalization battery capacity of the monomer based on the list of starting moment pairs includes: S420: Retrieve the list of starting moment pairs, and obtain the charging current values between the starting moment pairs in the list of starting moment pairs. Calculate the battery capacities of the two moment pairs respectively according to the ampere-hour integration method; S421: Take the average value of the battery capacities of the two moment pairs as the equalization battery capacity of the monomer; S422: Repeat steps S410 - 412 and steps S420 - S421 to calculate the equalization battery capacities of all monomers to be equalized compared with monomer b.

8. The method for estimating the full-time equalization capacity of the cloud based on the monomer voltage according to claim 1, characterized in that, The determination of the equalization scheme according to the equalization battery capacity and the equalization monomer list includes: Construct the execution limit of the battery management system BMS, where the BMS execution limit includes: the equalization battery capacity can at most turn on half of all the monomers and the corresponding equalization monomers cannot be adjacent; Based on the BMS execution limit, sort the equalization monomers corresponding to the equalization battery capacity in descending order, construct and initialize the final equalization list as empty, and traverse all the sorted equalization monomers in turn; Judge whether there is a monomer adjacent to the currently traversed monomer in the final equalization list; if yes, skip the currently traversed monomer; if not, add the currently traversed monomer to the final equalization list; until the number of equalization monomers is greater than the limit number or the sorted equalization monomer list is traversed, output the final equalization monomer list and the corresponding equalization capacity as the equalization scheme, and end the algorithm; The BMS performs the actual equalization operation according to the equalization scheme.

9. Cloud full-time equalization capacity estimation electronic device based on monomer voltage, characterized in that It includes: A memory and a processor, and the memory stores the executable instructions of the processor; wherein, the processor is configured to execute the method for estimating the cloud full-time equalization capacity based on the monomer voltage according to any one of claims 1 - 8 by executing the executable instructions.

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