Energy storage battery equalization control method, energy storage system and computer storage medium

Abstract

The invention discloses an energy storage battery equalization control method, an energy storage system and a computer storage medium. The energy storage battery equalization control method comprises the following steps: acquiring historical charging and discharging working condition information of an energy storage battery; determining an equalization time adjustment coefficient of the energy storage battery in the charging and discharging period according to the historical charging and discharging working condition information; and performing equalization control on the energy storage battery according to the equalization time adjustment coefficient. By adopting the method, the starting time of equalization control in the whole operation cycle of the energy storage battery can be prolonged, and the equalization efficiency of the energy storage battery is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage systems, and in particular to an energy storage battery balancing control method, an energy storage system and a computer storage medium. Background Art

[0002] At present, when performing balancing control on energy storage batteries, the cell voltage sampling line is used as the energy flow channel. Since the constrained balancing current of the sampling line is generally around 2A, the ability to transfer energy between single cells in a charge and discharge cycle is affected by the actual start-up time of the balancing control. In practical applications, the mainstream active balancing strategy is relatively conservative. When the single cell voltage is in a plateau period, the cell pressure difference is small, and balancing is usually not turned on at this time. Active balancing is usually turned on when the pressure difference is large at the end of charge and discharge. The active balancing is turned on for a short time in a cycle. As the capacity of the single cells continues to upgrade and iterate, the balancing effect of the energy storage battery will decrease. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one object of the present invention is to provide a method for controlling energy storage battery balance, which can increase the activation time of the balance control in the entire operation cycle of the energy storage battery and improve the balance efficiency of the energy storage battery.

[0004] A second objective of the present invention is to provide an energy storage system.

[0005] A third object of the present invention is to provide a computer storage medium.

[0006] In order to solve the above problems, an embodiment of the first aspect of the present invention provides a method for balancing control of an energy storage battery, comprising: obtaining historical charging and discharging operating condition information of the energy storage battery; determining a balancing time adjustment coefficient of the energy storage battery in the current charging and discharging cycle according to the historical charging and discharging operating condition information; and performing balancing control on the energy storage battery according to the balancing time adjustment coefficient.

[0007] According to the energy storage battery balancing control method of the embodiment of the present invention, the difference between the power of each single cell and the expected power is determined based on the historical charging and discharging condition information to determine its balancing time adjustment coefficient, so that the actual start time of the balancing control of each single cell in the energy storage battery is adjusted by the balancing time adjustment coefficient in this charging and discharging cycle, so that the energy carrying capacity of each single cell during the balancing management is increased, thereby improving the activation time of the balancing control in the entire operation cycle of the energy storage battery, improving the balancing efficiency of the energy storage battery, thereby better improving the consistency of the single cells, and extending the working time and service life of the energy storage system.

[0008] In some embodiments, the historical charge and discharge operating condition information includes at least an average voltage of single cells in the energy storage battery and a charge and discharge terminal voltage of each single cell, and determining the balancing time adjustment coefficient of the energy storage battery in the current charge and discharge cycle according to the historical charge and discharge operating condition information includes: calculating the voltage difference between the charge and discharge terminal voltage of each single cell of the energy storage battery in the previous charge and discharge cycle and the average voltage; and determining the balancing time adjustment coefficient of each single cell in the current charge and discharge cycle according to the voltage difference.

[0009] In some embodiments, the voltage difference is proportional to the balancing time adjustment coefficient.

[0010] In some embodiments, the balancing time adjustment coefficient of each single battery cell in the current charge and discharge cycle is determined based on the voltage difference, including: configuring multiple voltage difference intervals, wherein each voltage difference interval is set with a corresponding balancing time adjustment coefficient; determining a target voltage difference interval for the voltage difference of each single battery cell; and using the balancing time adjustment coefficient corresponding to the target voltage difference interval as the balancing time adjustment coefficient of each single battery cell in the current charge and discharge cycle.

[0011] In some embodiments, the energy storage battery is balanced controlled according to the balancing time adjustment coefficient, including: obtaining a basic balancing start-up time; determining an actual balancing adjustment time of each single cell according to the basic balancing start-up time and the balancing time adjustment coefficient corresponding to each single cell; and the energy storage battery is balanced controlled according to the actual balancing adjustment time of each single cell.

[0012] In some embodiments, the energy storage battery is balanced controlled according to the actual balancing adjustment time of each single cell, including: determining a first type of single cell that needs to be charged and a second type of single cell that needs to be discharged according to the actual balancing adjustment time of each single cell; matching the first type of single cells with the second type of single cells in pairs to determine a cell matching group; in each cell matching group, balancing the single cell corresponding to the minimum actual balancing adjustment time with the single cell corresponding to the maximum actual balancing adjustment time.

[0013] In some embodiments, the method further includes: after each battery cell matching group completes balancing control, counting the target single battery cells that have not completed balancing among all single battery cells; determining the remaining adjustment time for each target single battery cell; and performing balancing control on each target single battery cell according to the charging and discharging demand state of each target single battery cell and the remaining adjustment time.

[0014] In some embodiments, balancing control is performed on each target single cell according to the charge and discharge demand state of each target single cell and the remaining time to be adjusted, including: determining the available high-power cells and available low-power cells in the balanced single cells; if the charge and discharge demand state of the target single cell is a charging demand state, controlling the available high-power cells to charge the target single cells until the charging time of the available high-power cells reaches the remaining time to be adjusted; if the charge and discharge demand state of the target single cell is a discharging demand state, controlling the target single cell to charge the available low-power cells until the charging time of the target single cell reaches the remaining time to be adjusted.

[0015] In some embodiments, each target single cell is balanced controlled according to the charge and discharge demand state of each target single cell and the remaining time to be adjusted, including: if the charge and discharge demand state of the target single cell is a charging demand state, controlling the auxiliary power supply of the energy storage battery to charge the target single cell until the charging time of the target single cell reaches the remaining time to be adjusted.

[0016] In some embodiments, the historical charge and discharge operating condition information also includes a charge and discharge capacity value, and the determining the actual equalization adjustment time of each single cell according to the equalization start-up basic time and the equalization time adjustment coefficient corresponding to each single cell includes: obtaining a first charge and discharge capacity value of the energy storage battery in the previous charge and discharge cycle and a second charge and discharge capacity value of the energy storage battery in the previous charge and discharge cycle; determining a capacity comparison result according to the first charge and discharge capacity value and the second charge and discharge capacity value; determining a equalization correction coefficient of the energy storage battery in this charge and discharge cycle according to the capacity comparison result; and determining the actual equalization adjustment time of each single cell according to the equalization correction coefficient, the equalization start-up basic time and the equalization time adjustment coefficient corresponding to each single cell.

[0017] In some embodiments, before determining the actual equalization adjustment duration, the method further includes: performing data optimization on the equalization correction coefficient and / or the equalization time adjustment coefficient using a single-objective optimization algorithm.

[0018] In some embodiments, the method further includes: during the initial operation stage of the energy storage battery, determining the change in charge and discharge capacity of the energy storage battery in n consecutive charge and discharge cycles; if it is determined that the change in charge and discharge capacity is in a decreasing state, prohibiting the balancing control of the energy storage battery and issuing a balancing fault alarm.

[0019] A second aspect of the present invention provides an energy storage system, comprising: at least one processor; a memory communicatively connected to at least one of the processors; wherein the memory stores a computer program executable by at least one of the processors, and when at least one of the processors executes the computer program, the energy storage battery balancing control method described in the above embodiment is implemented.

[0020] According to the energy storage system of the embodiment of the present invention, by executing the energy storage battery balancing control method of the above embodiment, the activation time of balancing control in the entire operation cycle of the energy storage battery can be increased, and the balancing efficiency of the energy storage battery can be improved.

[0021] A third aspect of the present invention provides a computer storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the energy storage battery balancing control method described in the above embodiment.

[0022] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 is a flow chart of a method for controlling energy storage battery balancing according to an embodiment of the present invention; Figure 2 is a flow chart of an energy storage battery balancing control method according to another embodiment of the present invention; Figure 3 is a structural block diagram of an energy storage system according to an embodiment of the present invention.

[0024] Reference numerals: Energy storage system 10; Processor 1; Memory 2. DETAILED DESCRIPTION

[0025] Embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. Embodiments of the present invention are described in detail below.

[0026] In order to solve the above problems, a first embodiment of the present invention provides a method for balancing control of an energy storage battery. The method can increase the activation time of balancing control in the entire operation cycle of the energy storage battery and improve the balancing efficiency of the energy storage battery.

[0027] Reference below Figure 1 The energy storage battery balancing control method according to an embodiment of the present invention is described as follows: Figure 1As shown, the method includes: step S1-step S3.

[0028] Step S1, obtaining historical charging and discharging condition information of the energy storage battery.

[0029] The energy storage battery includes a plurality of single cells, and the single cells may be lithium iron phosphate cells. The historical charge and discharge condition information may be understood as information generated by the energy storage battery during past charge and discharge conditions.

[0030] Step S2, determining the balancing time adjustment coefficient of the energy storage battery in the current charging and discharging cycle according to the historical charging and discharging operating condition information.

[0031] The balancing time adjustment coefficient is a coefficient for optimizing the actual start time of the balancing function when the single cell in the energy storage battery performs balancing control under actual operating conditions. The actual operating conditions may be charging conditions, discharging conditions, and static conditions, etc., and there is no restriction on this.

[0032] Specifically, the power difference of each single cell in the energy storage battery when the power under the historical charging and discharging conditions is balanced and adjusted to reach its expected power is determined through the historical charging and discharging condition information, and the balancing time adjustment coefficient of each single cell is calibrated according to the size of the power difference under the historical charging and discharging conditions, so as to determine the balancing time adjustment coefficient of the energy storage battery in this charging and discharging cycle by calibrating the balancing time adjustment coefficient of each single cell.

[0033] Step S3, performing balancing control on the energy storage battery according to the balancing time adjustment coefficient.

[0034] Specifically, the balancing time adjustment coefficient of the energy storage battery in this charging and discharging cycle is determined based on the historical charging and discharging condition information. This charging and discharging cycle includes a plateau period and a non-plateau period. In this charging and discharging cycle, the actual opening time of the balancing function is optimized and adjusted by the balancing time adjustment coefficient, wherein the optimization adjustment can be to increase or decrease the actual opening time of the balancing function, that is, whether it is a plateau period or a non-plateau period, the actual opening time of each single cell for balancing control is adjusted by the balancing time adjustment coefficient, so that each single cell is balanced according to the corrected actual opening time of each single cell, so that the energy carrying capacity of each single cell during the balancing management is increased, thereby improving the activation time of the balancing control in the entire operation cycle of the energy storage battery, improving the balancing efficiency of the energy storage battery, thereby better improving the consistency of the single cell, and extending the working time and service life of the energy storage system. In addition, the balancing time adjustment coefficient of each single cell is determined by the historical charging and discharging condition information, so that the actual opening time can be adjusted according to the power situation of each single cell, so that the power of each single cell can meet the balancing adjustment requirements.

[0035] According to the energy storage battery balancing control method of the embodiment of the present invention, the difference between the power of each single cell and the expected power is determined based on the historical charging and discharging condition information to determine its balancing time adjustment coefficient, so that the actual start time of the balancing control of each single cell in the energy storage battery is adjusted by the balancing time adjustment coefficient in this charging and discharging cycle, so that the energy carrying capacity of each single cell during the balancing management is increased, thereby improving the activation time of the balancing control in the entire operation cycle of the energy storage battery, improving the balancing efficiency of the energy storage battery, thereby better improving the consistency of the single cells, and extending the working time and service life of the energy storage system.

[0036] In some embodiments, the historical charge and discharge condition information includes at least the average voltage of the single cells in the energy storage battery and the charge and discharge terminal voltage of each single cell. Determining the balancing time adjustment coefficient of the energy storage battery in the current charge and discharge cycle according to the historical charge and discharge condition information includes: calculating the voltage difference between the charge and discharge terminal voltage of each single cell and the average voltage in the previous charge and discharge cycle of the energy storage battery; and determining the balancing time adjustment coefficient of each single cell in the current charge and discharge cycle according to the voltage difference. The average voltage may be the average voltage of each single cell of all single cells in the energy storage battery in the previous charge and discharge cycle.

[0037] Specifically, in the present application, a balancing time adjustment coefficient is calibrated according to the voltage difference between the charge and discharge terminal voltage and the average voltage of the single cell, wherein the balancing time adjustment coefficient is related to the capacity and model of the single cell, and the voltage difference between the charge and discharge terminal voltage and the average voltage of each single cell in the last charge and discharge cycle of the energy storage battery is calculated, and then the balancing time adjustment coefficient of each single cell energy storage battery in the last charge and discharge cycle is set according to the voltage difference, and the balancing time adjustment coefficient is used as the balancing time adjustment coefficient of each single cell in the current charge and discharge cycle, thereby obtaining the balancing time adjustment coefficient of each single cell in the current charge and discharge cycle, so as to adjust the actual start time of the balancing control of each single cell through the balancing time adjustment coefficient.

[0038] Exemplarily, when the energy storage battery is put into use for the first time, it is necessary to complete the initial charge and discharge cycle first, and record the charge and discharge power, capacity, operating environment temperature, and the voltage difference between the charge and discharge terminal voltage and the average voltage of each single cell, wherein the initial charge and discharge cycle includes three charge and discharge cycles, and the operating conditions of the three charge and discharge cycles are similar, and the operating conditions include charge and discharge power and operating temperature, etc., and there is no specific restriction on this. In addition, the number of charge and discharge cycles in the initial charge and discharge cycle can be adjusted according to actual conditions. In the three charge and discharge cycles, the voltage difference between the charge and discharge terminal voltage and the average voltage of each single cell is calculated, and the balance time adjustment coefficient of each single cell in the corresponding charge and discharge cycle is calibrated according to the voltage difference, as a balance time adjustment coefficient calibration table, thereby, by the size of the voltage difference between the charge and discharge terminal voltage and the average voltage of each single cell in this charge and discharge cycle, the balance time adjustment coefficient calibration table is queried to obtain the balance time adjustment coefficient of each single cell in this charge and discharge cycle. It can be understood that the balancing time adjustment coefficient determined by the third charge-discharge cycle is better than the balancing time adjustment coefficients determined by the first two charge-discharge cycles.

[0039] In an embodiment, the balancing time adjustment coefficient of each single cell in the current charging and discharging cycle can also be determined according to the capacity difference of each single cell in the previous charging and discharging cycle of the energy storage battery. That is to say, the balancing time adjustment coefficient is set according to the capacity difference of each single cell in the previous charging and discharging cycle of the energy storage battery, and the balancing time adjustment coefficient is used as the balancing time adjustment coefficient of each single cell in the current charging and discharging cycle.

[0040] In some embodiments, the voltage difference is proportional to the balancing time adjustment coefficient. That is to say, when the voltage difference between the charge and discharge terminal voltage of the single cell and the average voltage is larger, it means that the remaining power of the single cell under the charge and discharge condition is larger, and the balancing time of the balancing control of the single cell is longer, that is, the balancing time adjustment coefficient is larger. Specifically, when the voltage difference between the charge terminal voltage of the single cell and the average voltage is larger, it means that the single cell needs to replenish or release more power during the balancing management, and the balancing start time of the balancing control of the single cell is longer, that is, the balancing time adjustment coefficient is larger; when the voltage difference between the discharge terminal voltage of the single cell and the average voltage of the discharge terminal voltage of all the single cells in the energy storage battery is larger, it means that the single cell needs to replenish or release more power during the balancing management, and the balancing start time of the balancing control of the single cell is longer, that is, the balancing time adjustment coefficient is larger. From this, it can be inferred that the voltage difference is proportional to the balancing time adjustment coefficient.

[0041] In some embodiments, the balancing time adjustment coefficient of each single battery cell in the current charge and discharge cycle is determined according to the voltage difference, including: configuring multiple voltage difference intervals, wherein each voltage difference interval is set with a corresponding balancing time adjustment coefficient; determining a target voltage difference interval for the voltage difference of each single battery cell; and using the balancing time adjustment coefficient corresponding to the target voltage difference interval as the balancing time adjustment coefficient of each single battery cell in the current charge and discharge cycle.

[0042] Specifically, the voltage difference between the charge and discharge terminal voltage of each single cell and the average voltage is calculated through the historical charge and discharge conditions of the single cell, and multiple voltage difference intervals are configured. Each voltage difference interval is calibrated with a balancing time adjustment coefficient. The larger the upper limit and lower limit of the voltage difference interval are, the larger the balancing time adjustment coefficient is. Based on this, in this charge and discharge cycle, the voltage difference of each single cell is calculated, and the target voltage difference interval of the voltage difference is determined. The balancing time adjustment coefficient corresponding to the target voltage difference interval is used as the balancing time adjustment coefficient of each single cell in this charge and discharge cycle, so that the actual start time of the balancing control of each single cell is adjusted by the balancing time adjustment coefficient.

[0043] Table 1

[0044] Where ΔVx is the voltage difference, 0<ΔV in Table 1 th1 <ΔV th2 <…<ΔV th-max , for the voltage difference range limit ΔV in charging condition, discharging condition and static condition th1 , ΔV th2 ,…,ΔV th-max It can be adjusted according to actual needs. adjn <… adj2 adj1 <0 adjn+1 <… adj-max , balance time adjustment coefficient B adj Can be adjusted according to actual needs, balance time adjustment coefficient B adj A negative number indicates that the voltage of the single cell is low and needs to be charged. The balancing time adjustment coefficient B adj A positive number indicates that the voltage of the single cell is high and needs to be discharged.

[0045] Exemplarily, when the target voltage difference range of the voltage difference of the single cell is ΔVx≤-ΔV th-max , query Table 1 to obtain the equalization time adjustment coefficient B adjn , B adjn ​​​​As the balancing time adjustment coefficient of the single cell in this charge and discharge cycle.

[0046] In some embodiments, the energy storage battery is balanced controlled according to the balancing time adjustment coefficient, including: obtaining the basic balancing start time; determining the actual balancing adjustment time of each single cell according to the basic balancing start time and the balancing time adjustment coefficient corresponding to each single cell; and the energy storage battery is balanced controlled according to the actual balancing adjustment time of each single cell.

[0047] Specifically, the basic time for balancing is obtained, wherein the basic time for balancing is the minimum time for balancing management of single cells according to actual calibration. Since a long time when the balancing function of the energy storage battery is turned on during balancing management will generate a lot of heat, which will cause the balancing efficiency of the energy storage battery to deteriorate, the minimum time is the minimum operating time experimentally calibrated to ensure the balancing efficiency during each balancing management cycle, and the minimum time can be adjusted according to the model of the energy storage battery. Since the balancing time adjustment coefficient corresponding to each single cell is the coefficient for optimizing the basic time for balancing according to the historical charging and discharging condition information when each single cell is balanced under the historical charging and discharging conditions, the basic time for balancing is corrected based on the balancing time adjustment coefficient corresponding to each single cell, that is, according to the basic time for balancing ΔT and the balancing time adjustment coefficient B corresponding to each single cell. adj Determine the actual balancing adjustment time of each single cell, that is, the actual balancing adjustment time t of each single cell = the balancing time adjustment coefficient B corresponding to each single cell adj ×ΔT, and then balance control is performed on the energy storage battery according to the actual balance adjustment time of each single cell, so that each single cell is balanced controlled according to the actual opening time of each single cell after adjustment during the entire charge and discharge cycle, so that the energy carrying capacity of each single cell in the charge and discharge cycle is increased, thereby increasing the activation time of the balance control in the entire operation cycle of the energy storage battery, improving the balance efficiency of the energy storage battery, thereby better improving the consistency of the single cells, and extending the working time and service life of the energy storage system.

[0048] In some embodiments, the energy storage battery is balanced controlled according to the actual balancing adjustment time of each single cell, including: determining a first type of single cell that needs to be charged and a second type of single cell that needs to be discharged according to the actual balancing adjustment time of each single cell; matching the first type of single cells with the second type of single cells in pairs to determine a cell matching group; in each cell matching group, the single cell corresponding to the minimum actual balancing adjustment time is balanced controlled by the single cell corresponding to the maximum actual balancing adjustment time.

[0049] In the prior art, in actual applications, when the voltage of a single cell is at a plateau, the cell pressure difference is small and equalization is usually not turned on. Active equalization is only turned on when the pressure difference is large at the end of charge and discharge. The active equalization is turned on for a short time in a charge and discharge cycle, especially as the capacity of the energy storage cell is continuously upgraded and iterated, resulting in poor equalization effect of the energy storage battery.

[0050] In the embodiment, according to the charge and discharge voltage change curve of the single cell, it is divided into a plateau period and a non-plateau period, wherein the plateau voltage range is 3.15V~3.3V, and the non-plateau voltage range is 2.7V~3.15V or 3.3V~3.65V, wherein the voltage range of the plateau and non-plateau periods can be adjusted.

[0051] Specifically, the balancing control includes active balancing control. The active balancing control transfers the energy of the single cells with high power among all the single cells to the single cells with low power. In each charge and discharge cycle, when each single cell reaches a plateau under the charge and discharge conditions, the single cells with actual balancing adjustment time greater than 0 among all the single cells are regarded as the second type of single cells that need to be discharged, and the single cells with actual balancing adjustment time less than 0 among all the single cells are regarded as the first type of single cells that need to be charged. The single cells are sorted according to the actual balancing adjustment time of each single cell. When active balancing control is performed on multiple single cells, the actual balancing adjustment time can be used to sort the cells. The first type of single cell and the second type of single cell are matched in pairs to form a cell matching group, that is, in the actual balancing adjustment time sorting result of the single cell, the first type of single cell with the maximum actual balancing adjustment time and the second type of single cell are matched in pairs, and so on, until the first type of single cell and the second type of single cell with the minimum actual balancing adjustment time are matched in pairs, so as to obtain multiple cell matching groups of the first type of single cell and the second type of single cell, and in each cell matching group, the single cell corresponding to the maximum actual balancing adjustment time is used to balance the single cell corresponding to the minimum actual balancing adjustment time.

[0052] That is to say, if the absolute value of the actual balancing adjustment time of the first type of single cell that needs to be charged is lower than the actual balancing adjustment time of the second type of single cell that needs to be discharged, at this time, the single cell corresponding to the maximum actual balancing adjustment time is the second type of single cell, and the single cell corresponding to the minimum actual balancing adjustment time is the first type of single cell, then the second type of single cell is controlled to discharge the first type of cell according to the minimum actual balancing adjustment time to meet the charging balancing adjustment of the first type of cell. At this time, the first type of single cell in the cell matching group completes charging balancing, and the second type of single cell has not completed discharge balancing. The second type of single cell still needs discharge balancing. Before balancing management, the actual balancing adjustment time of the first type of single cell is recorded as T1, and the actual balancing adjustment time of the second type of single cell is recorded as T2. After balancing management, the actual balancing adjustment time of the first type of single cell is adjusted to 0, and the actual balancing adjustment time of the second type of single cell is adjusted to T2-|T1. |; If the absolute value of the actual balancing adjustment time of the first type of single cell that needs to be charged is higher than the actual balancing adjustment time of the second type of single cell that needs to be discharged, at this time, the single cell corresponding to the maximum actual balancing adjustment time is the first type of single cell, and the single cell corresponding to the minimum actual balancing adjustment time is the second type of single cell, then the second type of single cell is controlled to discharge the first type of single cell according to the minimum actual balancing adjustment time to meet the discharge balancing adjustment of the second type of single cell. At this time, the second type of single cell in the cell matching group has completed balancing, and the first type of single cell has not completed balancing. The first type of single cell still needs charging balancing. Since the actual balancing adjustment time of the first type of single cell is recorded as T1 before balancing management, and the actual balancing adjustment time of the second type of single cell is recorded as T2, after balancing management, the actual balancing adjustment time of the first type of single cell is adjusted to |T1|-T2, and the actual balancing adjustment time of the second type of single cell is adjusted to 0.

[0053] Therefore, when each single cell reaches a plateau under the charge and discharge conditions, the present application performs balancing control through the actual balancing adjustment time of each single cell, thereby increasing the time when the energy storage system is actively balanced during a charge and discharge cycle, especially as the capacity of the energy storage cell is continuously upgraded and iterated, thereby further improving the balancing effect of the energy storage battery.

[0054] Based on this, after each battery cell matching group completes the balancing control, the target single battery cells that have not completed balancing among all the single battery cells are counted; the remaining adjustment time of each target single battery cell is determined; and balancing control is performed on each target single battery cell according to the charging and discharging demand state and the remaining adjustment time of each target single battery cell.

[0055] Specifically, after the single cell corresponding to the minimum actual balancing adjustment time is balanced by the single cell corresponding to the maximum actual balancing adjustment time in each battery cell matching group, there are first-category single cells or second-category single cells that have not completed balancing. After the balancing control is completed in each battery cell matching group, the target single cells that have not completed balancing among all the single cells are counted, and the target single cells may be first-category single cells or second-category single cells. The remaining adjustment time of each target single cell is determined, and then the balancing control is performed on each target single cell according to the charging and discharging demand state of each target single cell and the remaining adjustment time. For example, if the target single cell is of the first category If the target single cell is a single cell, the charge and discharge demand state is charging, and the remaining time to be adjusted can be expressed as |T1|-T2. The first type of single cell is charged according to the remaining time to be adjusted |T1|-T2, so that the first type of single cell that has not completed the balanced adjustment completes the charging balanced adjustment; if the target single cell is a second type of single cell, the charge and discharge demand state is discharging, and the remaining time to be adjusted can be expressed as T2-|T1|. The second type of single cell is discharged according to the remaining time to be adjusted T2-|T1|, so that the second type of single cell that has not completed the balanced adjustment completes the discharging balanced adjustment, thereby achieving the balance of the target single cell that has not completed the balanced adjustment.

[0056] In some embodiments, balancing control is performed on each target single cell according to the charge and discharge demand state and the remaining time to be adjusted of each target single cell, including: determining the available high-power cells and the available low-power cells in the balanced single cells; if the charge and discharge demand state of the target single cell is a charging demand state, controlling the available high-power cells to charge the target single cell until the charging time of the available high-power cells reaches the remaining time to be adjusted; if the charge and discharge demand state of the target single cell is a discharging demand state, controlling the target single cell to charge the available high-power cells until the charging time of the target single cell reaches the remaining time to be adjusted.

[0057] Specifically, when the target single cell that has not completed balancing is controlled again under the charging condition of the energy storage battery, the available high-power cells and available low-power cells in the balanced single cells are determined. If the charge and discharge demand state of the target single cell is the charging demand state, that is, the first type of single cell that has not completed balancing needs to be charged, the active balancing channel between the available high-power cells and the target single cell is controlled to be opened, so as to control the available high-power cells to charge the target single cell, that is, to distribute the charging demand of the target single cell to the available high-power cells, and to charge the first type of single cell that has not completed balancing by periodically calling the available high-power cells until the charging time of the high-power cells reaches the remaining time to be adjusted, that is, the charging time of the high-power cells for the first type of single cells reaches the remaining time to be adjusted. Adjust the time so that the first type of single battery that has not completed the equalization adjustment can complete the discharge equalization adjustment; when the energy storage battery is in the discharge condition, if the charge and discharge demand state of the target single battery cell is the discharge demand state, that is, the second type of single battery cell that has not completed the equalization needs to be discharged, then the active equalization channel between the target single battery cell and the available low-power battery cell is controlled to open, so as to control the target single battery cell to charge the available low-power battery cell that is periodically called, that is, the discharge demand of the second type of single battery cell that has not completed the equalization is apportioned to the available low-power battery cell, until the charging time of the second type of single battery cell for the target single battery cell reaches the remaining time to be adjusted, that is, the available low-power battery cells are evenly divided according to the remaining time to be adjusted of the target single battery cell, so that the second type of single battery cell that has not completed the equalization adjustment can complete the discharge equalization adjustment.

[0058] In some embodiments, each target single cell is balanced controlled according to the charge and discharge demand state and the remaining time to be adjusted of each target single cell, including: if the charge and discharge demand state of the target single cell is a charging demand state, controlling the auxiliary power supply of the energy storage battery to charge the target single cell until the charging time of the target single cell reaches the remaining time to be adjusted.

[0059] Specifically, when the energy storage battery performs balancing control on the target single cell that has not completed balancing again under the discharge or static condition, if the charge and discharge demand state of the target single cell is the charging demand state, that is, the first type of single cell that has not completed balancing needs to be charged, the auxiliary power supply of the energy storage battery is controlled to charge the target single cell until the charging time of the target single cell reaches the remaining adjustment time, so that the first type of single cell that has not completed balancing adjustment completes the discharge balancing adjustment.

[0060] In an embodiment, when the energy storage battery is under charging or static conditions, and the target single cell that has not completed equalization is controlled again, if the charge and discharge demand state of the target single cell is a discharge demand state, that is, the second type of single cell that has not completed equalization needs to be discharged, the passive equalization channel of the second type of single cell that has not completed equalization is opened to discharge the excess energy of the second type of single cell that has not completed equalization through the passive equalization channel until the discharge time of the target single cell reaches the remaining adjustment time, so that the second type of single cell that has not completed equalization adjustment completes the discharge equalization adjustment. In addition, it should be noted that the passive equalization channel opening time can be converted according to the size of the active and passive equalization currents. For example, if the active equalization current is 2A and the passive equalization current is 100mA, the passive equalization channel opening time is 20 times the required active equalization time, 2A / 100mA=20, and there is no minimum time limit for the passive equalization channel opening time.

[0061] In some embodiments, the historical charge and discharge operating condition information also includes a charge and discharge capacity value, and the actual balance adjustment time of each single cell is determined according to the balance start basic time and the balance time adjustment coefficient corresponding to each single cell, including: obtaining a first charge and discharge capacity value of the energy storage battery in the previous charge and discharge cycle and a second charge and discharge capacity value of the energy storage battery in the previous charge and discharge cycle; determining a capacity comparison result according to the first charge and discharge capacity value and the second charge and discharge capacity value; determining a balance correction coefficient of the energy storage battery in this charge and discharge cycle according to the capacity comparison result; and determining the actual balance adjustment time of each single cell according to the balance correction coefficient, the balance start basic time and the balance time adjustment coefficient corresponding to each single cell.

[0062] Specifically, a first charge and discharge capacity value of the energy storage battery in the previous charge and discharge cycle and a second charge and discharge capacity value of the energy storage battery in the previous charge and discharge cycle are obtained; a capacity comparison result is determined according to the first charge and discharge capacity value and the second charge and discharge capacity value; if the first charge and discharge capacity value and the second charge and discharge capacity value are substantially the same, the capacity comparison result is that the capacity remains substantially unchanged; if the first charge and discharge capacity value is lower than the second charge and discharge capacity value, the capacity comparison result is that the capacity increases; if the first charge and discharge capacity value is higher than the second charge and discharge capacity value, the capacity comparison result is that the capacity decreases, and then the capacity comparison result of the energy storage battery in this charge and discharge cycle is determined according to the capacity comparison result. That is to say, if the capacity comparison result shows that the capacity remains basically unchanged, it means that the balancing effect of the previous charge and discharge cycle is poor, and the balancing correction coefficient Kx is a value of Kx>1 to increase the balancing time adjustment coefficient; if the capacity comparison result shows that the capacity increases, it means that the balancing effect of the previous charge and discharge cycle is good, and the balancing correction coefficient Kx is 1 to control the balancing time adjustment coefficient to remain unchanged; if the capacity comparison result shows that the capacity decreases, it means that the balancing adjustment of the previous charge and discharge cycle is excessive, and the balancing correction coefficient Kx is a value in the range of 0≤Kx<1 to reduce the balancing time adjustment coefficient. In addition, it should be noted that the charge and discharge power curve, operating temperature, etc. of the energy storage battery in the previous charge and discharge cycle and the previous charge and discharge cycle are consistent or similar.

[0063] Then, according to the balancing correction coefficient Kx, the balancing start basic time ΔT and the balancing time adjustment coefficient B corresponding to each single cell adj Determine the actual equalization adjustment time of each single cell. The actual equalization adjustment time of each single cell is t=Kx×B adj ×ΔT, when the balancing correction coefficient Kx is a value of Kx>1, the balancing time adjustment coefficient of each single cell increases to increase the actual balancing adjustment time of each single cell; when the balancing correction coefficient Kx is 1, the balancing time adjustment coefficient of each single cell remains unchanged, so that the actual balancing adjustment time of each single cell remains unchanged; when the balancing correction coefficient Kx is a value in the range of 0≤Kx<1, the balancing time adjustment coefficient of each single cell decreases, so that the actual balancing adjustment time of each single cell decreases.

[0064] In some embodiments, before determining the actual balancing adjustment time, a single-objective optimization algorithm is used to perform data optimization on the balancing correction coefficient and / or the balancing time adjustment coefficient, wherein the single-objective optimization algorithm may be a genetic algorithm or a neural network, for example, the single-objective optimization is a charge and discharge capacity value.

[0065] In some embodiments, during the initial operation stage of the energy storage battery, the change in charge and discharge capacity of the energy storage battery during n consecutive (n≥2) charge and discharge cycles is determined; if it is determined that the change in charge and discharge capacity is in a decreasing state, the balancing control of the energy storage battery is prohibited, and a balancing fault alarm is issued.

[0066] For example, when the energy storage battery is put into use for the first time, it is necessary to complete an initial charge and discharge cycle. In the initial charge and discharge cycle, when it is determined that the capacity of each single cell is close to or shows a steady increase in three charge and discharge cycles, the balancing time adjustment coefficient corresponding to the third charge and discharge cycle of each single cell is used as the balancing time adjustment coefficient of each single cell in this charge and discharge cycle. Conversely, if the capacity of each single cell decreases significantly in the three charge and discharge cycles, it is prohibited to use active balancing control for the energy storage battery and an alarm is reported.

[0067] In the embodiment, during the initial charge and discharge operation of the energy storage battery, the real-time voltage difference of the single cell is used for balancing control in the whole process. When the real-time voltage difference of the single cell is higher than the first preset pressure difference, the corresponding active balancing channel is opened to transfer the energy of the high-voltage single cell to the low-voltage single cell. When the real-time voltage difference of the single cell is less than the second preset pressure difference, the corresponding active balancing channel is closed. The first preset pressure difference and the second preset pressure difference can be adjusted, and the preset pressure difference can be calibrated according to the actual situation.

[0068] Reference below Figure 2 The energy storage battery balancing control method according to an embodiment of the present invention is illustrated by way of example, and the specific contents are as follows.

[0069] Step S4: the energy storage battery completes its initial operation.

[0070] Step S5, calculating the voltage difference between the charge and discharge terminal voltage of each single cell and the average voltage of the energy storage battery in the last charge and discharge cycle.

[0071] Step S6, determining the balancing time adjustment coefficient of each single cell in the current charge and discharge cycle according to the voltage difference.

[0072] Step S7: when each single cell of the energy storage battery reaches a plateau during the current charge and discharge cycle, balance control is performed on each single cell.

[0073] Step S8, optimizing the balancing time adjustment coefficient according to the balancing adjustment effect of each single cell, and returning to step S5.

[0074] A second aspect of the present invention provides an energy storage system 10, such as Figure 3 As shown, the energy storage system 10 includes: at least one processor 1 and a memory 2 communicatively connected to the at least one processor 1 .

[0075] The memory 2 stores a computer program that can be executed by at least one processor 1 , and when the at least one processor 1 executes the computer program, the energy storage battery balancing control method of the above embodiment is implemented.

[0076] In an embodiment, the energy storage system includes a data acquisition and recording module for collecting information such as charging and discharging power, charging and discharging capacity, operating environment temperature, and ΔVx; a balancing control implementation module for controlling the opening and closing of balancing channels between corresponding single cells according to the energy storage battery balancing control method; a balancing effect evaluation module for comparing the operating data of adjacent charging and discharging cycles after the balancing implementation is completed, mainly analyzing the changes in system capacity and operating end pressure difference to evaluate the balancing effect; a balancing adjustment coefficient optimization module for optimizing the balancing correction coefficient and / or balancing time adjustment coefficient using a single-objective optimization algorithm according to the balancing effect evaluation result.

[0077] According to the energy storage system of the embodiment of the present invention, by executing the energy storage battery balancing control method of the above embodiment, the activation time of balancing control in the entire operation cycle of the energy storage battery can be increased, and the balancing efficiency of the energy storage battery can be improved.

[0078] A third aspect of the present invention provides a computer storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the energy storage battery balancing control method of the above embodiment is implemented.

[0079] In the description of this specification, any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code including one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present invention belong.

[0080] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection with one or more wires (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0081] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0082] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0083] In addition, each functional unit in each embodiment of the present invention may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0084] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present invention. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

[0085] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0086] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for controlling energy storage battery balance, characterized in that: include: Obtain historical charging and discharging condition information of energy storage batteries; Determine the balancing time adjustment coefficient of the energy storage battery in the current charging and discharging cycle according to the historical charging and discharging operating condition information; Performing balancing control on the energy storage battery according to the balancing time adjustment coefficient; The historical charge and discharge condition information includes at least the average voltage of the single cells in the energy storage battery and the charge and discharge terminal voltage of each single cell. The balancing time adjustment coefficient of the energy storage battery in the current charge and discharge cycle is determined according to the historical charge and discharge condition information, including: Calculating the voltage difference between the charge and discharge terminal voltage of each single cell of the energy storage battery in the last charge and discharge cycle and the average voltage; The balancing time adjustment coefficient of each single battery cell in this charge and discharge cycle is determined according to the voltage difference.

2. The energy storage battery balancing control method according to claim 1, characterized in that: The voltage difference is proportional to the balancing time adjustment coefficient.

3. The energy storage battery balancing control method according to claim 2, characterized in that: Determining the balancing time adjustment coefficient of each single cell in the current charge and discharge cycle according to the voltage difference includes: Configure multiple voltage difference intervals, wherein each voltage difference interval has a corresponding balancing time adjustment coefficient; Determine the target voltage difference range of the voltage difference of each single cell; The balancing time adjustment coefficient corresponding to the target voltage difference interval range is used as the balancing time adjustment coefficient of each single battery cell in this charge and discharge cycle.

4. The energy storage battery balancing control method according to any one of claims 1 to 3, characterized in that: The energy storage battery is balanced and controlled according to the balance time adjustment coefficient, including: Get the basic time for balance opening; Determine the actual balancing adjustment time of each single cell according to the balancing start basic time and the balancing time adjustment coefficient corresponding to each single cell; The energy storage battery is balanced and controlled according to the actual balance adjustment time of each single battery cell.

5. The energy storage battery balancing control method according to claim 4, characterized in that: The energy storage battery is balanced and controlled according to the actual balance adjustment time of each single cell, including: Determine the first type of single cell that needs to be charged and the second type of single cell that needs to be discharged according to the actual balancing adjustment time of each single cell; Matching the first type of single battery cells with the second type of single battery cells in pairs to determine a battery cell matching group; In each battery cell matching group, the single battery cell corresponding to the maximum actual balancing adjustment time is used to perform balancing control on the single battery cell corresponding to the minimum actual balancing adjustment time.

6. The energy storage battery balancing control method according to claim 5, characterized in that: The method further comprises: After each cell matching group completes the balancing control, the target single cells that have not completed balancing among all single cells are counted; Determine the remaining adjustment time of each target single cell; Each target single cell is balanced and controlled according to the charge and discharge demand state of each target single cell and the remaining time to be adjusted.

7. The energy storage battery balancing control method according to claim 6, characterized in that: The method of performing a balancing control on each target single cell according to the charge and discharge demand state of each target single cell and the remaining time to be adjusted includes: Determine the available high-power cells and available low-power cells in the balanced single cells; If the charge and discharge requirement state of the target single battery cell is a charging requirement state, controlling the available high-capacity battery cell to charge the target single battery cell until the charging time of the available high-capacity battery cell reaches the remaining time to be adjusted; If the charge and discharge requirement state of the target single cell is the discharge requirement state, the target single cell is controlled to charge the available low-power cell until the charging time of the target single cell reaches the remaining time to be adjusted.

8. The energy storage battery balancing control method according to claim 6, characterized in that: The method of performing a balancing control on each target single cell according to the charge and discharge demand state of each target single cell and the remaining time to be adjusted includes: If the charge and discharge requirement state of the target single cell is a charging requirement state, the auxiliary power supply of the energy storage battery is controlled to charge the target single cell until the charging time of the target single cell reaches the remaining time to be adjusted.

9. The energy storage battery balancing control method according to claim 4, characterized in that: The historical charge and discharge operating condition information also includes a charge and discharge capacity value, and the actual balance adjustment time of each single cell is determined according to the balance start basic time and the balance time adjustment coefficient corresponding to each single cell, including: Acquire a first charge-discharge capacity value of the energy storage battery in the last charge-discharge cycle and a second charge-discharge capacity value of the energy storage battery in the last charge-discharge cycle; Determine a capacity comparison result according to the first charge-discharge capacity value and the second charge-discharge capacity value; Determine the balance correction coefficient of the energy storage battery in this charge and discharge cycle according to the capacity comparison result; The actual balancing adjustment time of each single cell is determined according to the balancing correction coefficient, the balancing start basic time and the balancing time adjustment coefficient corresponding to each single cell.

10. The energy storage battery balancing control method according to claim 9, characterized in that: Before determining the actual equalization adjustment duration, the method further includes: A single-objective optimization algorithm is used to perform data optimization on the equalization correction coefficient and / or the equalization time adjustment coefficient.

11. The energy storage battery balancing control method according to claim 1, characterized in that: The method further comprises: In the initial operation stage of the energy storage battery, determining the change of the charge and discharge capacity of the energy storage battery in n consecutive charge and discharge cycles, wherein n≥2; If it is determined that the change in the charge and discharge capacity is in a decreasing state, the balancing control of the energy storage battery is prohibited, and a balancing fault alarm is issued.

12. An energy storage system, characterized in that: include: at least one processor; a memory communicatively coupled to at least one of the processors; The memory stores a computer program that can be executed by at least one of the processors, and when at least one of the processors executes the computer program, the energy storage battery balancing control method according to any one of claims 1 to 11 is implemented.

13. A computer storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the energy storage battery balancing control method according to any one of claims 1 to 11 is implemented.

Images