Battery charging equalization method and system for energy storage

Abstract

The invention provides an energy storage battery charging equalization method and system, and the method comprises the steps: obtaining the state of charge of a battery module, and setting the range of the state of charge; if the state of charge is in a set state of charge range, balancing the abnormal cells based on a first abnormal cell voltage and a first normal cell voltage of the battery module and a plateau period start-stop voltage and start-stop capacity of a cell discharge curve; if the charge state is not in the set charge state range, determining a first charge-discharge capacity based on a second normal cell voltage and a cut-off voltage of the battery module, and determining a second charge-discharge capacity based on a second abnormal cell voltage and a cell SOC-voltage relation table of the battery module; and if the difference between the first charge-discharge capacity and the second charge-discharge capacity is within a set capacity difference range, balancing the abnormal battery cell according to the first charge-discharge capacity, otherwise, balancing the abnormal battery cell according to the second charge-discharge capacity.

Description

Technical Field

[0001] The present invention relates to the technical field of battery power compensation and equalization for energy storage, and in particular to a battery power compensation and equalization method and system for energy storage. Background Art

[0002] In recent years, energy storage technology has been vigorously developed in the new energy field, especially in recent years, the country has been increasingly supporting the new energy industry. Mobile energy storage container system is the main way and method of building energy storage system at present. It is mainly used in wind power, solar energy, and industrial peak power consumption, and plays a significant economic value. Because it is easy to transport and install, it has won the unanimous consensus of the industry.

[0003] However, in the long-term use of energy storage containers, the voltage of the entire module or a cell in the module will be higher or lower than the overall voltage level due to various reasons. This will cause the entire energy storage container to have insufficient energy during charging and discharging, excessive pressure difference alarm, and safety accidents. This phenomenon is caused by the short board effect of a certain unit, and will seriously affect the design service life of the container. Summary of the invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] To this end, a first object of the present invention is to provide a method for equalizing energy storage batteries to extend the life of the energy storage batteries.

[0006] The second object of the present invention is to provide a battery power compensation and balancing system for energy storage.

[0007] A third objective of the present invention is to provide an electronic device.

[0008] A fourth object of the present invention is to provide a computer-readable storage medium.

[0009] To achieve the above-mentioned purpose, the first aspect of the present invention provides a method for equalizing the energy storage battery, comprising:

[0010] Obtain the state of charge of the battery module and set the state of charge range;

[0011] If the state of charge is within the set state of charge range, balancing the abnormal cells based on the first abnormal cell voltage and the first normal cell voltage of the battery module, and the start and end voltages and the start and end capacities of the plateau period of the cell discharge curve;

[0012] If the state of charge is not within the set state of charge range, the first charge and discharge capacity is determined based on the second normal battery cell voltage and the cut-off voltage of the battery module, and the second charge and discharge capacity is determined based on the second abnormal battery cell voltage of the battery module and the battery cell SOC-voltage relationship table; if the difference between the first charge and discharge capacity and the second charge and discharge capacity is within the set capacity difference range, the abnormal battery cells are balanced according to the first charge and discharge capacity, otherwise the abnormal battery cells are balanced according to the second charge and discharge capacity.

[0013] In the method of the first aspect of the present invention, the abnormal cells are balanced based on the first abnormal cell voltage and the first normal cell voltage of the battery module, and the start and end voltages and start and end capacities of the plateau period of the cell discharge curve, including: determining the capacity-voltage relationship coefficient based on the start and end voltages and start and end capacities of the plateau period of the cell discharge curve; obtaining a voltage difference based on the first abnormal cell voltage and the first normal cell voltage; obtaining a balanced capacity based on the voltage difference and the capacity-voltage relationship coefficient, and balancing the abnormal cells based on the balanced capacity.

[0014] In the method of the first aspect of the present invention, the first normal battery cell voltage is obtained based on an average value or a median value of voltages of normal battery cells of the battery module.

[0015] In the method of the first aspect of the present invention, if the state of charge is not within the set state of charge range, the first charge and discharge capacity is determined based on the second normal battery cell voltage and the cut-off voltage of the battery module, and the second charge and discharge capacity is determined based on the second abnormal battery cell voltage of the battery module and the battery cell SOC-voltage relationship table, including: if the state of charge is less than the lower limit of the set state of charge range, the first discharge capacity is determined based on the second normal battery cell voltage and the discharge cut-off voltage of the battery module; the experimental battery cell is discharged to the discharge cut-off voltage using constant power to obtain the battery cell SOC-voltage relationship table under the discharge state; the second discharge capacity is calculated based on the second abnormal battery cell voltage, the discharge cut-off voltage and the battery cell SOC-voltage relationship table under the discharge state.

[0016] In the method of the first aspect of the present invention, if the state of charge is not within the set state of charge range, the first charge and discharge capacity is determined based on the second normal battery cell voltage and the cut-off voltage of the battery module, and the second charge and discharge capacity is determined based on the second abnormal battery cell voltage of the battery module and the battery cell SOC-voltage relationship table, including: if the state of charge is greater than the upper limit of the set state of charge range, the first charge capacity is determined based on the second normal battery cell voltage and the charging cut-off voltage of the battery module; the experimental battery cell is charged to the charging cut-off voltage using constant power to obtain the battery cell SOC-voltage relationship table under the charging state; the second charge capacity is calculated based on the second abnormal battery cell voltage, the charging cut-off voltage and the battery cell SOC-voltage relationship table under the charging state.

[0017] In the method of the first aspect of the present invention, if the difference between the first charge and discharge capacity and the second charge and discharge capacity is within a set capacity difference range, the abnormal battery cells are balanced according to the first charge and discharge capacity, otherwise the abnormal battery cells are balanced according to the second charge and discharge capacity, including: when the state of charge is less than the lower limit of the set state of charge range, if the difference between the first discharge capacity and the second discharge capacity is within the set discharge capacity difference range, the abnormal battery cells are balanced according to the first discharge capacity, otherwise the abnormal battery cells are balanced according to the second discharge capacity; when the state of charge is greater than the upper limit of the set state of charge range, if the difference between the first charge capacity and the second charge capacity is within the set charge capacity difference range, the abnormal battery cells are balanced according to the first charge capacity, otherwise the abnormal battery cells are balanced according to the second charge capacity.

[0018] In the method of the first aspect of the present invention, the second normal cell voltage is obtained based on the median value of the voltages of the normal cells of the battery module.

[0019] To achieve the above-mentioned purpose, the second aspect of the present invention proposes a battery power equalization system for energy storage, comprising:

[0020] An acquisition module is used to obtain the state of charge of the battery module and set the state of charge range;

[0021] A first balancing module, configured to balance the abnormal cells based on a first abnormal cell voltage and a first normal cell voltage of the battery module, and a plateau start and end voltage and a start and end capacity of a cell discharge curve if the state of charge is within the set state of charge range;

[0022] The second balancing module is used to determine the first charge and discharge capacity based on the second normal battery cell voltage and the cut-off voltage of the battery module if the state of charge is not within the set state of charge range, and also determine the second charge and discharge capacity based on the second abnormal battery cell voltage of the battery module and the battery cell SOC-voltage relationship table; if the difference between the first charge and discharge capacity and the second charge and discharge capacity is within the set capacity difference range, the abnormal battery cell is balanced according to the first charge and discharge capacity, otherwise the abnormal battery cell is balanced according to the second charge and discharge capacity.

[0023] To achieve the above-mentioned purpose, the third aspect of the present invention proposes an electronic device, comprising: a processor, and a memory communicatively connected to the processor; the memory stores computer-executable instructions; the processor executes the computer-executable instructions stored in the memory to implement the method proposed in the first aspect of the present invention.

[0024] To achieve the above-mentioned purpose, the fourth aspect of the present invention proposes a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, they are used to implement the method proposed in the first aspect of the present invention.

[0025] The energy storage battery replenishment and equalization method, system, electronic device and storage medium provided by the present invention obtain the state of charge of the battery module and set the state of charge range; if the state of charge is within the set state of charge range, the abnormal cells are equalized based on the first abnormal cell voltage and the first normal cell voltage of the battery module, and the start and end voltages and start and end capacities of the plateau period of the cell discharge curve; if the state of charge is not within the set state of charge range, the first charge and discharge capacity is determined based on the second normal cell voltage and the cut-off voltage of the battery module, and the second charge and discharge capacity is determined based on the second abnormal cell voltage of the battery module and the cell SOC-voltage relationship table; if the difference between the first charge and discharge capacity and the second charge and discharge capacity is within the set capacity difference range, the abnormal cells are equalized according to the first charge and discharge capacity, otherwise the abnormal cells are equalized according to the second charge and discharge capacity. In this case, the state of charge of the battery module is comprehensively considered, and different methods are used to balance the battery modules with different state of charge ranges. Among them, for the battery modules with a state of charge within the set state of charge range, the abnormal / normal cell voltage, and the plateau start and end voltage and start and end capacity of the cell discharge curve are comprehensively considered to balance the abnormal cells; for the battery modules not within the set state of charge range, two groups of charge and discharge capacities are obtained by comprehensively considering the abnormal / normal cell voltage, cut-off voltage and cell SOC-voltage relationship table, and then the final charge and discharge capacity is determined in combination with the set capacity difference range to balance the abnormal cells. Compared with the existing single power replenishment method, it can better extend the life of the energy storage battery.

[0026] 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

[0027] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0028] Figure 1 A schematic diagram of a flow chart of a method for balancing energy storage battery power provided by an embodiment of the present invention;

[0029] Figure 2 A schematic diagram of a discharge curve of a battery cell provided in an embodiment of the present invention;

[0030] Figure 3 A block diagram of a battery power balancing system for energy storage provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0031] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0032] The following describes the energy storage battery charging and balancing method and system according to the embodiments of the present invention with reference to the accompanying drawings.

[0033] The embodiment of the present invention provides a method for equalizing energy storage batteries to extend the life of the energy storage batteries.

[0034] Figure 1 A schematic diagram of a flow chart of a method for balancing energy storage batteries provided in an embodiment of the present invention.

[0035] like Figure 1 As shown, the energy storage battery charging and balancing method includes the following steps:

[0036] Step S101, obtaining the state of charge of the battery module and setting the state of charge range.

[0037] In step S101 , the state of charge (SOC) of the battery module is obtained.

[0038] In step S101, the set state of charge range of the battery module is also obtained. For example, if the state of charge range is set to [10%, 90%], the lower limit of the state of charge range is set to 10% and the upper limit is set to 90%.

[0039] Step S102 : if the state of charge is within the set state of charge range, the abnormal cells are balanced based on the first abnormal cell voltage and the first normal cell voltage of the battery module, and the plateau start and end voltages and start and end capacities of the cell discharge curve.

[0040] In step S102, an abnormal cell is a single cell in the battery module that is higher than or lower than other cells in the entire battery module. Other cells in the battery module except the abnormal cell are normal cells.

[0041] In step S102, for a battery module whose state of charge is within a set state of charge range, the voltage of its abnormal cell is a first abnormal cell voltage. The first normal cell voltage is obtained based on the average value or median value of the voltages of the normal cells of the battery module.

[0042] In step S102, the abnormal cells are balanced based on the first abnormal cell voltage and the first normal cell voltage of the battery module, and the start and end voltages and the start and end capacities of the plateau period of the cell discharge curve, including: determining the capacity-voltage relationship coefficient based on the plateau period start and end voltages and the start and end capacities of the cell discharge curve; obtaining the voltage difference based on the first abnormal cell voltage and the first normal cell voltage; obtaining the balanced capacity based on the voltage difference and the capacity-voltage relationship coefficient, and balancing the abnormal cells based on the balanced capacity. Among them, the start and end voltages include the start voltage and the end voltage, and the start and end capacities include the start capacity and the end capacity.

[0043] Specifically, a lithium iron phosphate battery with a state of charge range of [10%, 90%] is taken as an example for explanation.

[0044] Figure 2 This is a schematic diagram of a discharge curve of a battery cell provided by an embodiment of the present invention. Figure 2 From the discharge curve of the lithium iron phosphate battery shown, it can be seen that there is a voltage plateau period (referred to as the plateau period) in the discharge of the lithium iron phosphate battery. During the plateau period, the rate of cell voltage drop is very slow, showing a linear change in the curve. Among them, the starting voltage of the plateau period is V1 and the ending voltage is V2. The starting capacity corresponding to the starting voltage V1 is M1, and the ending capacity corresponding to the ending voltage V2 is M2. Based on the starting and ending voltages and starting and ending capacities of the cell voltage plateau period, a relationship between capacity / voltage is obtained, that is, the capacity-voltage relationship coefficient. The capacity-voltage relationship coefficient N satisfies (M2-M1) / (V1-V2)=N.

[0045] For battery modules with SOC between 10% and 90%, a first abnormal cell voltage V3 is obtained in a stationary state, and the middle value of the voltages of other cells except the abnormal cells in the battery module is taken as the first normal cell voltage V4. The voltage difference between the two is calculated, and the absolute value V of the voltage difference satisfies V=|V3-V4|.

[0046] The balanced capacity is obtained based on the voltage difference and the capacity-voltage relationship coefficient, that is, the balanced capacity is N*V. If the voltage of the abnormal cell is lower than the voltage of the normal cell, the abnormal cell is charged and balanced based on the balanced capacity. If the voltage of the abnormal cell is higher than the voltage of the normal cell, the abnormal cell is discharged and balanced based on the balanced capacity. This achieves preliminary leveling.

[0047] In step S102, after the initial leveling, the entire battery module can be left to stand for a set time, for example, more than 30 minutes, and the voltage of the abnormal battery cell can be measured again. This step is repeated to adjust the charging and discharging of the abnormal battery cell until the difference between the first abnormal battery cell voltage and the first normal battery cell voltage is less than the set difference threshold (for example, 3mV), and the charging action can be stopped.

[0048] Step S103, if the state of charge is not within the set state of charge range, the first charge and discharge capacity is determined based on the second normal cell voltage and the cut-off voltage of the battery module, and the second charge and discharge capacity is determined based on the second abnormal cell voltage of the battery module and the cell SOC-voltage relationship table; if the difference between the first charge and discharge capacity and the second charge and discharge capacity is within the set capacity difference range, the abnormal cells are balanced according to the first charge and discharge capacity, otherwise the abnormal cells are balanced according to the second charge and discharge capacity.

[0049] In step S103, for a battery module whose state of charge is not within the set state of charge range, the voltage of its abnormal cell is a second abnormal cell voltage. The second normal cell voltage is obtained based on the middle value of the voltages of the normal cells of the battery module.

[0050] In step S103, if the state of charge is not within the set state of charge range, the first charge and discharge capacity is determined based on the second normal cell voltage and the cut-off voltage of the battery module, and the second charge and discharge capacity is determined based on the second abnormal cell voltage of the battery module and the cell SOC-voltage relationship table, including:

[0051] If the state of charge is less than the lower limit of the set state of charge range, the first discharge capacity is determined based on the second normal cell voltage and the discharge cut-off voltage of the battery module; the experimental cell is discharged to the discharge cut-off voltage using constant power to obtain a cell SOC-voltage relationship table under the discharge state; the second discharge capacity is calculated based on the second abnormal cell voltage, the discharge cut-off voltage and the cell SOC-voltage relationship table under the discharge state;

[0052] If the state of charge is greater than the upper limit of the set state of charge range, the first charging capacity is determined based on the second normal battery cell voltage and the charging cut-off voltage of the battery module; the experimental battery cell is charged to the charging cut-off voltage using constant power to obtain the battery cell SOC-voltage relationship table under the charging state; the second charging capacity is calculated based on the second abnormal battery cell voltage, the charging cut-off voltage and the battery cell SOC-voltage relationship table under the charging state.

[0053] In step S103, if the difference between the first charge and discharge capacity and the second charge and discharge capacity is within a set capacity difference range, the abnormal cells are balanced according to the first charge and discharge capacity, otherwise the abnormal cells are balanced according to the second charge and discharge capacity, including: when the state of charge is less than the lower limit of the set state of charge range, if the difference between the first discharge capacity and the second discharge capacity is within the set discharge capacity difference range, the abnormal cells are balanced according to the first discharge capacity, otherwise the abnormal cells are balanced according to the second discharge capacity; when the state of charge is greater than the upper limit of the set state of charge range, if the difference between the first charge capacity and the second charge capacity is within the set charge capacity difference range, the abnormal cells are balanced according to the first charge capacity, otherwise the abnormal cells are balanced according to the second charge capacity.

[0054] Specifically, taking the setting of the state of charge range to [10%, 90%] as an example, the following is explained:

[0055] If the SOC of the battery module is less than 10%, take the cell voltage corresponding to the middle value of the normal cell voltage in the battery module as the second normal cell voltage, use the specific current A1 to discharge the cell corresponding to the second normal cell voltage until the discharge cut-off voltage, for example, 2.5V, stop discharging, record the first discharge capacity Q1, and then use the specific current A1 to charge the cell corresponding to the second normal cell voltage according to the first discharge capacity Q1, so as to calibrate and confirm that the capacity range of the cells in the entire battery module is around the first discharge capacity Q1. For the remaining normal cells and abnormal cells in the battery module, use the same specific current A1 to discharge to the discharge cut-off voltage, for example, 2.5V, and then use the specific current A1 to charge according to the first discharge capacity Q1, so as to achieve balance. The cut-off condition of this balancing method uses the capacity as the cut-off condition, and the cut-off capacity is the first discharge capacity Q1.

[0056] If the SOC of the battery module is greater than 90%, the cell voltage corresponding to the middle value of the normal cell voltage in the battery module is taken as the second normal cell voltage, and the cell corresponding to the second normal cell voltage is charged using a specific current A2 until the charging cutoff voltage, for example, 3.65V, stops charging, and the first charging capacity Q2 is recorded. Then, the specific current A2 is used to discharge the cell corresponding to the second normal cell voltage according to the first charging capacity Q2, so as to calibrate and confirm that the capacity range of the cells in the entire battery module is around the first charging capacity Q2. For the remaining normal cells and abnormal cells in the battery module, the same specific current A2 is used to charge to the charging cutoff voltage, for example, 3.65V, and then the specific current A2 is used to discharge according to the first charging capacity Q2, so as to achieve balance. The cutoff condition of this balancing method uses capacity as the cutoff condition, and the cutoff capacity is the first charging capacity Q2.

[0057] In some embodiments, in step S103 , it is considered that the first discharge capacity Q1 or the first charge capacity Q2 may not be accurate, and the second charge and discharge capacity also needs to be comprehensively considered.

[0058] Specifically, taking a 280Ah cell as an example, the process of determining the second discharge capacity includes: discharging a single experimental cell of 280Ah at a constant power of 0.5P at room temperature of 25±2°C until the cell is discharged to a discharge cut-off voltage, such as 2.5V, and calculating a corresponding relationship between the cell SOC and the cell voltage (i.e., a cell SOC-voltage relationship table), as shown in Table 1. By using the cell voltage bins corresponding to each SOC bin in Table 1, the voltage difference in each SOC bin interval is calculated, thereby calculating how many Ah of the required supplementary power (CCV) is required for each mV voltage in an uncertain SOC bin interval.

[0059] Table 1 Cell SOC-voltage relationship table

[0060]

[0061]

[0062] Based on the data in Table 1, taking the 0%-5% range as an example, the segmented coefficient relationship between each mV capacity and voltage is calculated as K=280Ah*5% / (2938.6mV-2499.9mV)=0.031912Ah / mV. The same method is used to calculate the segmented coefficient relationship K of all SOC segment intervals (i.e. all ranges in Table 1).

[0063] The entire experimental battery module is discharged at a normal discharge power of 0.5P to the lowest voltage of the entire experimental battery module to the discharge cut-off voltage, for example, 2.5V, and then all the cell voltages in the experimental battery module are extracted when the discharge is stopped at 2.5V, and the cell voltage V5 that needs to be supplemented is obtained, and the average voltage V6 of other normal cells in the experimental battery module is calculated, and the voltage segment interval where the cell voltage V5 that needs to be supplemented and balanced and the average voltage V6 are located is found;

[0064] Taking V5=2703mV and V6=3155mV as an example, it is necessary to calculate the voltage difference of the battery cells that need to be replenished and balanced in different voltage segments. Specifically, V5 is in the 0%-5% gear, V6 is in the 15%-20% gear, and there are a total of 4 gears from V5 to V6, among which V5 is in the 0%-5% gear, and the voltage difference corresponding to 2703mV-2938.6mV is calculated and recorded as V7, the voltage difference corresponding to the interval of 2938.7mV-3089.3mV is recorded as V8, the voltage difference corresponding to the interval of 3089.4mV-3136.4mV is recorded as V9, and the voltage difference corresponding to 3136.5mV-3155mV is V10. The segmented coefficient relationship K corresponding to the four gears is calculated, for example, the 0%-5% gear corresponds to K1, the 5%-10% gear corresponds to K2, the 10%-15% gear corresponds to K3, and the 15%-20% gear corresponds to K4, then the second discharge capacity Q3 satisfies Q3=V7*K1+V8*K2+V9*K3+V10*K10.

[0065] If the difference between the first discharge capacity Q1 and the second discharge capacity Q3 is within the set discharge capacity difference range, the abnormal cells are balanced according to the first discharge capacity Q1; otherwise, the abnormal cells are balanced according to the second discharge capacity Q3.

[0066] In the embodiment of the present invention, the second charging capacity can be obtained by analogy with the process of obtaining the second discharging capacity.

[0067] In some embodiments, if the SOC of the battery module cannot be obtained, the battery module can be directly balanced using the method of step S103 .

[0068] In some embodiments, after all the power replenishment and balancing work is completed, the battery module or system needs to be tested for normal charge and discharge, and the test verification should be at least one complete cycle to check whether the abnormal situation of the adjusted battery cell or module has been effectively improved. If the problem disappears, it means that the power replenishment method is feasible for it; if the problem still exists, it means that the abnormality of a single battery cell or the entire module is not caused by inconsistent capacity, and it is considered to be a performance problem of the battery cell or module itself. There is a safety hazard and a new battery cell or module needs to be replaced for re-matching.

[0069] In order to implement the above-mentioned embodiment, the present invention further proposes a battery power compensation and balancing system for energy storage.

[0070] Figure 3 This is a block diagram of a battery power equalization system for energy storage provided by an embodiment of the present invention.

[0071] like Figure 3 As shown, the energy storage battery power equalization system includes an acquisition module 11, a first equalization module 12 and a second equalization module 13, wherein:

[0072] An acquisition module 11 is used to acquire the state of charge of the battery module and set a range of the state of charge;

[0073] A first balancing module 12 is used to balance the abnormal cells based on the first abnormal cell voltage and the first normal cell voltage of the battery module, and the start and end voltages and the start and end capacities of the plateau period of the cell discharge curve if the state of charge is within a set state of charge range;

[0074] The second balancing module 13 is used to determine the first charge and discharge capacity based on the second normal cell voltage and the cut-off voltage of the battery module if the state of charge is not within the set state of charge range, and also determine the second charge and discharge capacity based on the second abnormal cell voltage of the battery module and the cell SOC-voltage relationship table; if the difference between the first charge and discharge capacity and the second charge and discharge capacity is within the set capacity difference range, the abnormal cell is balanced according to the first charge and discharge capacity, otherwise the abnormal cell is balanced according to the second charge and discharge capacity.

[0075] Furthermore, in a possible implementation of the embodiment of the present invention, in the first balancing module 12, the abnormal cells are balanced based on the first abnormal cell voltage and the first normal cell voltage of the battery module, and the start and end voltages and start and end capacities of the plateau period of the cell discharge curve, including: determining the capacity-voltage relationship coefficient based on the start and end voltages and start and end capacities of the plateau period of the cell discharge curve; obtaining the voltage difference based on the first abnormal cell voltage and the first normal cell voltage; obtaining the balanced capacity based on the voltage difference and the capacity-voltage relationship coefficient, and balancing the abnormal cells based on the balanced capacity.

[0076] Furthermore, in a possible implementation of the embodiment of the present invention, in the first balancing module 12, a first normal cell voltage is obtained based on an average value or an intermediate value of voltages of normal cells of the battery module.

[0077] Furthermore, in a possible implementation of an embodiment of the present invention, in the second balancing module 13, if the state of charge is not within the set state of charge range, the first charge and discharge capacity is determined based on the second normal cell voltage and the cut-off voltage of the battery module, and the second charge and discharge capacity is determined based on the second abnormal cell voltage and the cell SOC-voltage relationship table of the battery module, including: if the state of charge is less than the lower limit of the set state of charge range, the first discharge capacity is determined based on the second normal cell voltage and the discharge cut-off voltage of the battery module; the experimental cell is discharged to the discharge cut-off voltage using constant power to obtain the cell SOC-voltage relationship table under the discharge state; and the second discharge capacity is calculated based on the second abnormal cell voltage, the discharge cut-off voltage and the cell SOC-voltage relationship table under the discharge state.

[0078] Further, in a possible implementation of an embodiment of the present invention, in the second balancing module 13, if the state of charge is not within the set state of charge range, the first charge and discharge capacity is determined based on the second normal battery cell voltage and the cut-off voltage of the battery module, and the second charge and discharge capacity is determined based on the second abnormal battery cell voltage of the battery module and the battery cell SOC-voltage relationship table, including: if the state of charge is greater than the upper limit of the set state of charge range, the first charging capacity is determined based on the second normal battery cell voltage and the charging cut-off voltage of the battery module; the experimental battery cell is charged to the charging cut-off voltage using constant power to obtain the battery cell SOC-voltage relationship table under the charging state; and the second charging capacity is calculated based on the second abnormal battery cell voltage, the charging cut-off voltage and the battery cell SOC-voltage relationship table under the charging state.

[0079] Further, in a possible implementation of the embodiment of the present invention, in the second balancing module 13, if the difference between the first charge and discharge capacity and the second charge and discharge capacity is within a set capacity difference range, the abnormal battery cells are balanced according to the first charge and discharge capacity, otherwise the abnormal battery cells are balanced according to the second charge and discharge capacity, including: when the state of charge is less than the lower limit of the set state of charge range, if the difference between the first discharge capacity and the second discharge capacity is within the set discharge capacity difference range, the abnormal battery cells are balanced according to the first discharge capacity, otherwise the abnormal battery cells are balanced according to the second discharge capacity; when the state of charge is greater than the upper limit of the set state of charge range, if the difference between the first charge capacity and the second charge capacity is within the set charge capacity difference range, the abnormal battery cells are balanced according to the first charge capacity, otherwise the abnormal battery cells are balanced according to the second charge capacity.

[0080] Further, in a possible implementation of the embodiment of the present invention, in the second balancing module 13, a second normal cell voltage is obtained based on an intermediate value of voltages of normal cells of the battery module.

[0081] It should be noted that the above explanation of the embodiment of the energy storage battery power compensation and equalization method is also applicable to the energy storage battery power compensation and equalization system of this embodiment, and will not be repeated here.

[0082] In an embodiment of the present invention, the state of charge of the battery module is obtained and the state of charge range is set; if the state of charge is within the set state of charge range, the abnormal cells are balanced based on the first abnormal cell voltage and the first normal cell voltage of the battery module, and the start and end voltages and start and end capacities of the plateau period of the cell discharge curve; if the state of charge is not within the set state of charge range, the first charge and discharge capacity is determined based on the second normal cell voltage and the cut-off voltage of the battery module, and the second charge and discharge capacity is determined based on the second abnormal cell voltage of the battery module and the cell SOC-voltage relationship table; if the difference between the first charge and discharge capacity and the second charge and discharge capacity is within the set capacity difference range, the abnormal cells are balanced according to the first charge and discharge capacity, otherwise the abnormal cells are balanced according to the second charge and discharge capacity. In this case, the state of charge of the battery module is comprehensively considered, and different methods are used to balance the battery modules with different state of charge ranges. Among them, for the battery modules with a state of charge within the set state of charge range, the abnormal / normal cell voltage, and the plateau start and end voltage and start and end capacity of the cell discharge curve are comprehensively considered to balance the abnormal cells; for the battery modules not within the set state of charge range, two groups of charge and discharge capacities are obtained by comprehensively considering the abnormal / normal cell voltage, cut-off voltage and cell SOC-voltage relationship table, and then the final charge and discharge capacity is determined in combination with the set capacity difference range to balance the abnormal cells. Compared with the existing single power replenishment method, it can better extend the life of the energy storage battery.

[0083] The method and system of the present invention can complete the battery charging and balancing action faster and more scientifically. There is a systematic method to guide on-site after-sales personnel to perform charging and balancing according to the process, thereby improving the efficiency of after-sales work. It can reduce safety accidents that occur during the charging and balancing process due to improper operation or data errors, and at the same time improve the product's performance, reduce product safety risks, and extend the product's service life. Practical methods and data can replace previous personnel experience, and the data is traceable and scientific.

[0084] In order to implement the above embodiments, the present invention also proposes an electronic device, comprising: a processor, and a memory communicatively connected to the processor; the memory stores computer-executable instructions; the processor executes the computer-executable instructions stored in the memory to implement the method provided by the above embodiments.

[0085] In order to implement the above embodiments, the present invention further proposes a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, they are used to implement the methods provided by the above embodiments.

[0086] In order to implement the above embodiments, the present invention further provides a computer program product, including a computer program, which implements the methods provided by the above embodiments when executed by a processor.

[0087] In the description of the aforementioned embodiments, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. 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 representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0088] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0089] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code comprising 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.

[0090] 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 the instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose 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 of computer-readable media (a non-exhaustive list) 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), a fiber optic 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.

[0091] 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, a plurality of 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.

[0092] 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.

[0093] 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.

[0094] 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.

Claims

1. A method for equalizing the battery power for energy storage, characterized in that: include: Obtain the state of charge of the battery module and set the state of charge range; If the state of charge is within the set state of charge range, balancing the abnormal cells based on the first abnormal cell voltage and the first normal cell voltage of the battery module, and the start and end voltages and the start and end capacities of the plateau period of the cell discharge curve; If the state of charge is not within the set state of charge range, the first charge and discharge capacity is determined based on the second normal battery cell voltage and the cut-off voltage of the battery module, and the second charge and discharge capacity is determined based on the second abnormal battery cell voltage of the battery module and the battery cell SOC-voltage relationship table; if the difference between the first charge and discharge capacity and the second charge and discharge capacity is within the set capacity difference range, the abnormal battery cells are balanced according to the first charge and discharge capacity, otherwise the abnormal battery cells are balanced according to the second charge and discharge capacity.

2. The energy storage battery equalization method according to claim 1, characterized in that: The balancing of abnormal cells based on the first abnormal cell voltage and the first normal cell voltage of the battery module, and the start and end voltages and the start and end capacities of the plateau period of the cell discharge curve includes: Determine the capacity-voltage relationship coefficient based on the start and end voltages and the start and end capacities of the plateau period of the battery cell discharge curve; obtaining a voltage difference based on the first abnormal battery cell voltage and the first normal battery cell voltage; A balanced capacity is obtained based on the voltage difference and the capacity-voltage relationship coefficient, and abnormal cells are balanced based on the balanced capacity.

3. The energy storage battery equalization method according to claim 1, characterized in that: The first normal cell voltage is obtained based on an average value or a median value of voltages of normal cells of the battery module.

4. The energy storage battery equalization method according to claim 1, characterized in that: If the state of charge is not within the set state of charge range, determining the first charge and discharge capacity based on the second normal cell voltage and the cut-off voltage of the battery module, and determining the second charge and discharge capacity based on the second abnormal cell voltage of the battery module and the cell SOC-voltage relationship table, including: If the state of charge is less than a lower limit of the set state of charge range, determining a first discharge capacity based on a second normal cell voltage and a discharge cut-off voltage of the battery module; Use constant power to discharge the experimental battery cell to the discharge cut-off voltage to obtain the battery cell SOC-voltage relationship table under the discharge state; The second discharge capacity is calculated based on the second abnormal cell voltage, the discharge cut-off voltage, and a cell SOC-voltage relationship table in a discharge state.

5. The energy storage battery equalization method according to claim 4, characterized in that: If the state of charge is not within the set state of charge range, determining the first charge and discharge capacity based on the second normal cell voltage and the cut-off voltage of the battery module, and determining the second charge and discharge capacity based on the second abnormal cell voltage of the battery module and the cell SOC-voltage relationship table, including: If the state of charge is greater than an upper limit of the set state of charge range, determining a first charging capacity based on a second normal cell voltage and a charging cut-off voltage of the battery module; Use constant power to charge the experimental battery cell to the charging cut-off voltage to obtain the battery cell SOC-voltage relationship table under charging state; The second charging capacity is calculated based on the second abnormal battery cell voltage, the charge cut-off voltage, and a battery cell SOC-voltage relationship table under charging state.

6. The energy storage battery equalization method according to claim 5, characterized in that: If the difference between the first charge-discharge capacity and the second charge-discharge capacity is within the set capacity difference range, the abnormal cells are balanced according to the first charge-discharge capacity; otherwise, the abnormal cells are balanced according to the second charge-discharge capacity, including: When the state of charge is less than the lower limit of the set state of charge range, if the difference between the first discharge capacity and the second discharge capacity is within the set discharge capacity difference range, the abnormal cells are balanced according to the first discharge capacity, otherwise the abnormal cells are balanced according to the second discharge capacity; When the state of charge is greater than the upper limit of the set state of charge range, if the difference between the first charging capacity and the second charging capacity is within the set charging capacity difference range, the abnormal cells are balanced according to the first charging capacity, otherwise the abnormal cells are balanced according to the second charging capacity.

7. The energy storage battery equalization method according to claim 1, characterized in that: The second normal cell voltage is obtained based on a median value of voltages of normal cells of the battery module.

8. A battery power equalization system for energy storage, characterized in that: include: An acquisition module is used to obtain the state of charge of the battery module and set the state of charge range; A first balancing module, configured to balance the abnormal cells based on a first abnormal cell voltage and a first normal cell voltage of the battery module, and a plateau start and end voltage and a start and end capacity of a cell discharge curve if the state of charge is within the set state of charge range; The second balancing module is used to determine the first charge and discharge capacity based on the second normal battery cell voltage and the cut-off voltage of the battery module if the state of charge is not within the set state of charge range, and also determine the second charge and discharge capacity based on the second abnormal battery cell voltage of the battery module and the battery cell SOC-voltage relationship table; if the difference between the first charge and discharge capacity and the second charge and discharge capacity is within the set capacity difference range, the abnormal battery cell is balanced according to the first charge and discharge capacity, otherwise the abnormal battery cell is balanced according to the second charge and discharge capacity.

9. An electronic device, characterized in that: include: A processor, and a memory communicatively connected to the processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory to implement the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, which are used to implement the method according to any one of claims 1 to 7 when executed by a processor.

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