SOC estimation method, mobile power supply and readable storage medium

Abstract

The present invention discloses a SOC estimation method, a mobile power supply, and a readable storage medium. The method primarily calculates the power value of the mobile power supply at a fixed step length, then sequentially steps and superimposes the unit power, calculates the cumulative power of the mobile power supply from the last SOC change, compares the absolute value of the cumulative power with the power value at the fixed step length, and based on the comparison result, adds / subtracts the SOC value by a fixed step length or keeps the SOC value unchanged, and obtains the starting value of the cumulative power at the next moment. By obtaining the SOC value of the mobile power supply in this manner, in actual programming, only if judgments and addition and subtraction operations can be used instead of the division operation of the existing SOC estimation method, significantly reducing the amount of calculation required for SOC estimation, reducing the consumption of computing resources and the occupancy of storage space, greatly reducing the requirements for chip computing power and peripheral resources, reducing device energy consumption, and improving SOC estimation speed and computational stability.

Description

Technical Field

[0001] The present invention relates to the technical field of mobile power supply SOC estimation, and in particular to a SOC estimation method, a mobile power supply and a readable storage medium. Background Art

[0002] Currently, due to the high cost of electronic products in the portable micro-energy storage market, major manufacturers are searching for lower-cost alternative materials. When selecting alternative materials, they often choose low-cost chips with weak computing power or continuously reduce chip peripheral resources and performance. However, for micro-mobile power products, which involve a high level of calculations, such as SOC (State of Charge) estimation, only high-performance, strong, and fast chips are suitable. Pursuing only low-cost chips without simplifying the calculations will inevitably lead to incompatibility.

[0003] In chip operations, SOC estimation requires a large amount of computational overhead. The existing technology for SOC estimation mostly uses the ampere-hour integration method, which has the following formula:

[0004] Where C is the rated capacitance, η is the charge and discharge efficiency, and I is the current.

[0005] The algorithm uses operations such as addition, subtraction, multiplication, and division, which have huge computational overhead. Inexpensive chips with weak computing power cannot meet its computational requirements. Therefore, a low-cost SOC estimation algorithm is urgently needed. Summary of the Invention

[0006] To solve the above problems, embodiments of the present invention provide a SOC estimation method, a mobile power supply, and a readable storage medium.

[0007] To solve the above technical problems, a technical solution adopted in an embodiment of the present invention is to provide an SOC estimation method applied to a mobile power supply, the method comprising:

[0008] Step S1. Calculating the fixed-step power value of the mobile power supply;

[0009] Step S2. Step by step, superimpose the unit power in sequence to calculate the cumulative power of the mobile power supply from the last SOC change moment;

[0010] Step S3. Compare the absolute value of the accumulated power with the fixed step power value, and perform addition and subtraction operations based on the comparison result, taking the SOC value at the current moment and the starting value of the accumulated power at the next moment;

[0011] Step S4. After the SOC value is updated, if the accumulated power continues to change, repeat steps S2-S3; if the accumulated power no longer changes, keep the SOC value at the previous moment and save the accumulated power at the current moment;

[0012] Wherein, the step S2 includes: calculating the unit power according to a second formula; the second formula is:

[0013]

[0014] Where ΔQ n The unit power refers to the unit power within a certain SOC calculation cycle T2;

[0015] I n1 ,I n2 ,…,I nk is the sampling current in the nth SOC calculation cycle, n1, n2, …, nk are the sampling times in the nth SOC calculation cycle, and T2 is the SOC calculation cycle;

[0016] k=2 j And T1×k≤T2; j is a positive integer, and T1 is the sampling period.

[0017] Optionally, step S1 includes:

[0018] The fixed-step power value of the mobile power supply is obtained according to a first formula; wherein the first formula is:

[0019] ΔC=C×P×λ and

[0020] Wherein, ΔC is the power value of the fixed step, C is the rated capacity of the battery of the mobile power supply, P is the fixed step, λ is the proportional coefficient that changes with the ambient temperature, I max is the maximum over-current value that the mobile power supply can withstand under extreme conditions, and T2 is the SOC calculation cycle of the mobile power supply.

[0021] Optionally, step S2 includes:

[0022] The accumulated power of the mobile power supply since the last SOC change is calculated according to a third formula; wherein the third formula is:

[0023]

[0024] Among them, Q st Indicates the starting value of the accumulated power, N is a positive integer.

[0025] Optionally, step S3 includes:

[0026] When the absolute value of the accumulated power is greater than or equal to the power value of the fixed step, the fixed step is added or subtracted from the SOC value at the previous moment according to the charge and discharge state of the mobile power supply as the current SOC value, and the power value of the accumulated power minus or added with the fixed step is used as the starting value of the accumulated power at the next moment;

[0027] When the absolute value of the accumulated power is less than the power value of the fixed step, the SOC value at the previous moment is maintained as the current SOC value, and the accumulated power is saved as the starting value of the accumulated power at the next moment.

[0028] Optionally, the method further includes correcting the current SOC value obtained in step S3 at the end stage of charging and discharging of the mobile power supply.

[0029] Optionally, at the end stage of charging and discharging of the mobile power supply, correcting the SOC of the mobile power supply includes:

[0030] During the charging process of the mobile power supply, if the voltage U of the mobile power supply is greater than the charging terminal voltage threshold U up , and when the SOC value of the mobile power supply is not fully charged, a correction process is introduced:

[0031] SOC′=SOC+α(UU up );

[0032] Among them, SOC' is the corrected SOC value during charging; SOC is the SOC value before correction; α is the charging correction parameter.

[0033] Optionally, at the end stage of charging and discharging of the mobile power supply, correcting the SOC of the mobile power supply includes:

[0034] During the discharge process of the mobile power supply, if the voltage U of the mobile power supply is less than the discharge end voltage threshold U de , and when the SOC value of the mobile power supply is not empty, a correction process is introduced:

[0035] SOC"=SOC-β(U de -U);

[0036] Among them, SOC" is the SOC value after correction during discharge; SOC is the SOC value before correction; β is the discharge correction parameter.

[0037] In order to solve the above technical problems, another technical solution adopted in the embodiment of the present invention is to provide a mobile power supply, which includes:

[0038] at least one processor; and,

[0039] a memory communicatively connected to the at least one processor; wherein,

[0040] The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the state of charge calculation method.

[0041] In order to solve the above technical problems, another technical solution adopted by the embodiment of the present invention is: providing a readable storage medium, wherein the readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the state of charge calculation method.

[0042] Beneficial effects: This application adopts the above SOC estimation method. In actual programming, only if judgment and addition and subtraction operations can be used to replace the division operation of the existing SOC estimation method, which greatly reduces the amount of calculation when estimating SOC, reduces the consumption of computing resources and the occupancy of storage space, greatly reduces the requirements for chip computing power and peripheral resources, reduces equipment energy consumption, improves SOC estimation speed and improves calculation stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] One or more embodiments are exemplarily illustrated by corresponding drawings, which do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0044] Figure 1 is a schematic diagram of an application scenario provided by an embodiment of the present invention;

[0045] Figure 2 A schematic structural diagram of a controller for executing an SOC estimation method provided by an embodiment of the present invention;

[0046] Figure 3 is a flow chart of a SOC estimation method provided by an embodiment of the present invention;

[0047] Figure 4 This is a schematic diagram of a SOC estimation method process provided by an embodiment of the present invention;

[0048] Figure 5 This is a schematic diagram of the accumulated power of the mobile power supply provided by an embodiment of the present invention from the start of charging to a certain moment;

[0049] Figure 6 This is a schematic diagram of the accumulated power of the mobile power supply provided by an embodiment of the present invention from the start to the end of charging;

[0050] Figure 7 This is a comparison diagram of SOC estimation curves when the mobile power supply is charging provided by an embodiment of the present invention;

[0051] Figure 8 This is a structural block diagram of an SOC estimation device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0053] It should be noted that, unless there is a conflict, the various features of the embodiments of the present invention may be combined with each other and are all within the scope of protection of the present invention. In addition, although the functional modules are divided in the device schematics and the logical order is shown in the flowcharts, in some cases, the steps shown or described may be performed in a different order than the module division in the device schematics or the order in the flowcharts.

[0054] Unless otherwise defined, all technical and scientific terms used in this specification have the same meanings as those commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification are intended solely for the purpose of describing specific embodiments and are not intended to limit the invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0055] The mobile power supply in this application refers to a portable micro energy storage power supply with a screen display (which can display the SOC value) that can power digital products and small household appliances.

[0056] The SOC estimation method and device can be applied to the SOC estimation process of a mobile power supply. Figure 1 As shown, Figure 1This is an application scenario provided by an embodiment of the present invention, which includes: a power grid 10, a load 20, and a mobile power supply 30. The mobile power supply 30 is connected to the power grid 10 and the load 20, respectively. The mobile power supply 30 includes a controller 31 and a display 32, and the controller 31 is connected to the display 32. The mobile power supply 30 is a portable charger that can store electrical energy. The operating states of the mobile power supply 30 include charging and discharging. The power grid 10 is used to charge the mobile power supply 30, and the mobile power supply 30 is used to discharge the load 20. When the mobile power supply 30 is charging or discharging, the controller 31 controls the display 32 to display the current SOC value of the mobile power supply 30, that is, the current charge level of the mobile power supply 30. The display 32 displays, including but not limited to, numbers from 1 to 100. When the mobile power supply 30 is charging, the numbers displayed on the display 32 gradually increase; when the mobile power supply 30 is discharging, the numbers displayed on the display 32 gradually decrease. Furthermore, the SOC value refers to the ratio of the remaining capacity of the mobile power supply to the capacity of the mobile power supply when it is fully charged. The value range of the SOC is 0% to 100%. When the SOC value is equal to 0%, it means that the mobile power supply is completely discharged. When the SOC value is 100%, it means that the mobile power supply is fully charged. By knowing the value of the SOC, the operation of the mobile power supply can be controlled.

[0057] In this embodiment, the battery capacity of the power bank is C, and the SOC range displayed on the display is 0-100%. The accuracy of the SOC value can be 1%, 0.1%, or 0.01%, depending on actual needs. The lower the accuracy, the higher the accuracy of the SOC estimation. In actual applications, the SOC range can be displayed as a number without a unit. Therefore, to facilitate viewing of the numbers alone, the SOC accuracy can be set to 1. The SOC range can be adjusted to 0%-100%, 0‰-1000‰, or 0-10000, as required. The display then displays the numbers 0-100, 0-1000, or 0-10000.

[0058] The power grid 10 may be a mains electricity source or any device capable of charging the mobile power source 30. The load 20 includes but is not limited to electronic products such as wireless phones, laptop computers, and other handheld mobile devices.

[0059] In one embodiment of the present invention, Figure 2 As shown, the controller 31 includes at least one processor 311. Figure 2 In the example, a processor 311 is used; the memory 321 connected to the at least one processor 311 is communicated with, Figure 2 The bus connection is taken as an example.

[0060] The memory 321 stores instructions that can be executed by the at least one processor 311 , and the instructions are executed by the at least one processor 311 so that the at least one processor 311 can perform the following SOC estimation method.

[0061] Memory 321, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules, such as the program instructions / modules corresponding to the SOC estimation method in the embodiments of the present invention. Processor 311 executes the non-volatile software programs, instructions, and modules stored in memory 321 to execute various functional applications and data processing of mobile power supply 30, thereby implementing the SOC estimation method in the following method embodiments.

[0062] The memory 321 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and application programs required for at least one function. In addition, the memory 321 may include a high-speed random access memory and may also include a non-volatile memory. For example, it may include at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory 321 may optionally include a memory remotely located relative to the processor 311.

[0063] The one or more modules are stored in the memory 321, and when executed by the one or more processors 311, perform the SOC estimation method in any of the following method embodiments, for example, performing the following described Figure 3 The method steps in .

[0064] The mobile power supply 30 is also connected to other devices for better executing the method provided by the embodiment of the present invention, such as being electrically connected to a display screen or other display, being remotely connected to a communication device of a target user, etc., which are not listed here one by one.

[0065] The mobile power supply 30 can execute the method provided by the embodiment of the present invention and has functional modules corresponding to the method. For technical details not fully described in this embodiment, please refer to the method provided by the embodiment of the present invention.

[0066] See also Figure 3 and Figure 4 , Figure 3 is a flow chart of an SOC estimation method provided by an embodiment of the present invention. Figure 4 Schematic diagram of an SOC estimation process provided by an embodiment of the present invention, wherein the method is applied to the above-mentioned mobile power supply, such as Figure 3 As shown, the following steps are included:

[0067] S01. Calculate a fixed-step power value of the mobile power supply.

[0068] Taking into account the impact of temperature on battery charging and discharging, the fixed-step power value is added with the ambient temperature factor, that is, temperature correction is performed. Specifically, the fixed-step power value of the mobile power supply is calculated according to the following formula; wherein, the formula is:

[0069] ΔC=C×P×λ

[0070] Among them, ΔC is the power value of the fixed step; C is the rated capacity of the battery of the mobile power supply. P is a fixed step, expressed as a unit range, and can reflect the accuracy of SOC. The higher the accuracy, the smaller the P value, specifically a certain percentage value; for example: when the SOC range is 1‰-1000‰, P takes a value of 1‰, that is, 0.1%; when the SOC range is 1%-100%, P takes a value of 1%. λ is a proportional coefficient that changes with ambient temperature (value: 0~1). For example, when the external ambient temperature is detected to be below 0 degrees Celsius, λ=0.8; when it is greater than 0 degrees Celsius, λ=1. When setting the range of change of P value and λ, the following conditions must be met:

[0071]

[0072] Among them I max is the maximum overcurrent value the mobile power bank can withstand under extreme conditions, and T2 is the SOC calculation period for the mobile power bank. Since the SOC in the method described herein is accumulated or decremented using a fixed step size P, the maximum change in SOC during each calculation period is P. Therefore, it is necessary to ensure that the accumulated charge during T2 when the mobile power bank is charged or discharged at maximum current is less than ΔC.

[0073] S02. The unit power is sequentially and step-by-step added to calculate the cumulative power of the mobile power supply from the last SOC change.

[0074] Specifically, the unit power is sequentially and step-by-step added according to the unit time to calculate the cumulative power Q of the mobile power supply from the last SOC change moment.

[0075] Optionally, in this embodiment, the unit time is the mobile power supply SOC calculation period T2, and the acquisition of unit power requires first obtaining the mobile power supply SOC calculation period T2, the current sampling period T1, and the sampling current I. Among them, the smaller the current sampling period T1, the more it can reflect the actual changes. However, in actual applications, considering the performance and necessity of the chip in the mobile power supply (for example, in cases where the changes are relatively slow, such as temperature), the current sampling period T1 can be at the level of hundreds of milliseconds or seconds, and the sampling current I can be at the level of milliseconds or microseconds; preferably, the current sampling period T1 can be 10ms. If the SOC calculation period T2 is too small, the calculation amount will be too large. If the SOC calculation period T2 is too large, it may cause the mobile power supply SOC to change less smoothly; optionally, the value of the SOC calculation period T2 can be 100ms. The current sampling period T1 and the SOC calculation period T2 can be adjusted and set according to actual conditions.

[0076] Specifically, the SOC calculation period T2 of the mobile power supply is much longer than the sampling period T1 of the mobile power supply. Therefore, within one SOC calculation period T2, there are multiple current sampling periods T1, and the sampling current in each current sampling period T1 may be different. Therefore, the unit power ΔQ in each SOC calculation period is n Using the integral method, it is expressed as the following formula:

[0077]

[0078] Where ΔQ n Refers to the unit power within a certain SOC calculation cycle T2.

[0079] Considering the actual programming implementation, the above integral formula needs to be discretized, that is, the average value of the current sampled multiple times is taken as the constant current within the calculation period T2.

[0080]

[0081]

[0082] I n1 ,I n2 ,…,I nk is the sampling current in the nth SOC calculation cycle, n1, n2, …, nk are the sampling times in the nth SOC calculation cycle, and T2 is the SOC calculation cycle.

[0083] In the above formula, although the k value can be obtained through only one division operation, it is still a division operation after all. To reduce the computational overhead, the k value is further optimized as follows:

[0084] k=2 j And T1×k≤T2;

[0085] Here, j is a positive integer. The advantage of setting k to a power of 2 is that the chip operates on binary numbers, and when the divisor is a power of 2, using left shift instead of division can speed up the operation.

[0086] It is understandable that, since the sampling current I corresponding to each sampling period T1 is definitely different, each unit of electricity will also be different.

[0087] For a certain current moment, the accumulated power is the sum of the accumulated power and the unit power at the previous moment, where Q n =Q n-1 +ΔQ n ;

[0088] Among them, the time difference between the current moment and the previous moment is T2, Q n Indicates the current accumulated power, Q n-1 Indicates the accumulated power at the previous moment, ΔQ n Indicates the unit electricity from the previous moment to the current moment.

[0089] When the last SOC change time is taken as the starting time, the above formula is further transformed into the following formula:

[0090]

[0091] Among them, Q st Indicates the starting value of the accumulated power, N is a positive integer.

[0092] It is understood that the above-mentioned unit time can be set according to actual needs, for example, the unit time is set to 2T2 or 3T2, and the corresponding unit power is also changed accordingly. The larger the unit time is set, the fewer the number of comparisons in the subsequent step S03 is, which can also reduce the chip's computing overhead to a certain extent.

[0093] S03. Compare the absolute value of the accumulated power with the fixed-step power value, and perform addition and subtraction operations based on the comparison result to obtain the SOC value at the current moment and the starting value of the accumulated power at the next moment.

[0094] Specifically, the absolute value of the accumulated power is compared with the power value of the fixed step. Whenever the absolute value of the accumulated power is greater than or equal to the power value of the fixed step, the fixed step is added or subtracted from the SOC value at the previous moment according to the charging and discharging state of the mobile power supply as the current SOC value, and the power value of the accumulated power minus or added with the fixed step is used as the starting value of the accumulated power at the next moment; when the absolute value of the accumulated power is less than the power value of the fixed step, the SOC value at the previous moment is maintained as the current SOC value, and the accumulated power is saved as the starting value of the accumulated power at the next moment.

[0095] As can be understood from the above, when the absolute value of the accumulated power is less than the power value of the fixed step, it is equivalent to performing an addition or subtraction operation, except that the number added or subtracted is 0.

[0096] When the mobile power supply is in operation, the mobile power supply obtains the charge and discharge status, and the processor periodically obtains the accumulated power of the mobile power supply. When the mobile power supply is in the charging state, the input is greater than the output, and the accumulated power is positive; when the mobile power supply is in the discharging state, the input is less than the output, and the accumulated power is negative.

[0097] Specifically, after each SOC calculation cycle T2, the accumulated power Q is compared with the power value ΔC of a fixed step.

[0098] When |Q|≥ΔC and the mobile power supply is in the charging state, a fixed step size is added to the SOC value at the previous moment as the current SOC value, and the accumulated power value minus the fixed step size is used as the starting value of the accumulated power at the next moment; when |Q|≥ΔC and the mobile power supply is in the discharging state, a fixed step size is subtracted from the SOC value at the previous moment as the current SOC value, and the accumulated power value plus the fixed step size is used as the starting value of the accumulated power at the next moment.

[0099] S04. After the SOC value is updated, when the accumulated power continues to change, steps S02-S03 are repeated; when the accumulated power no longer changes, the SOC value at the previous moment is maintained and the accumulated power at the current moment is saved.

[0100] Specifically, the accumulated power will continuously change while the mobile power supply is charging or discharging. When the mobile power supply stops charging or discharging, the accumulated power will not change. The starting time for calculating the accumulated power in step S02 changes with each cycle. The starting time is updated to the moment of each SOC change, and the corresponding starting value of the accumulated power is also updated to Q-ΔC.

[0101] The following is a schematic diagram showing steps S02-S04 in the SOC estimation process, taking charging of a mobile power supply at room temperature as an example. Figure 5 A schematic diagram of the accumulated power from the start of charging to a certain moment in the charging process of a mobile power bank. Figure 6 Schematic diagram of the total accumulated power from the start to the end of charging during the charging process of the mobile power supply.

[0102] like Figure 5 and 6 As shown, t M-1 Time is the starting time of a certain charging of the mobile power supply, t N1 is a certain moment in the charging process, t M Assume that the SOC value at the start of charging is 23.4% and the fixed step size P is 0.1%.

[0103] During the charging process, the current is sampled in each current sampling cycle T1 to obtain the real-time current; in each SOC calculation cycle T2, the unit power in this cycle is calculated first, and then the cumulative power and SOC are calculated.

[0104] For each unit power in the SOC calculation cycle T2, the calculation formula is as follows:

[0105]

[0106] Among them, k=8, n=1, 2,…, 8.

[0107] After each SOC calculation cycle, the accumulated power is calculated and compared with the fixed-step power value ΔC. In this example, the initial value of the accumulated power is 0, so: ΔQ1, ΔQ1+ΔQ2, ΔQ1+ΔQ2+ΔQ3, ΔQ1+ΔQ2+ΔQ3+ΔQ4, ..., ΔQ1+ΔQ2+...+ΔQ8 are all compared with ΔC. Assuming that in this example, ΔQ1+ΔQ2+...+ΔQ7<ΔC and ΔQ1+ΔQ2+...+ΔQ7+ΔQ8≥ΔC, then at t N1 At the moment, its SOC value is t M-1 The SOC value at the moment is added with the fixed step length P, i.e. 23.5%; then the accumulated power minus the fixed step length is used as the starting value of the accumulated power at the next moment, i.e. Q tN1 -ΔC, where Q tN1 =ΔQ1+ΔQ2+…+ΔQ8.

[0108] like Figure 6 As shown, the mobile power supply continues to charge, the accumulated power continues to change, and the above process continues to cycle. It should be noted that: for t N2For the time, the starting time of calculating the accumulated power is updated to t N1 At this moment, the initial value of the accumulated power is Q tN1 -ΔC, the accumulated charge is t N1 Time to t N2 The amount of electricity accumulated at the moment; similarly, for t N3 , t N4 , t M In terms of time, every time the SOC value changes, the starting time for calculating the accumulated power is updated to the time of the last SOC change, and the starting value of the accumulated power is updated to the accumulated power at the time of the last SOC change minus ΔC. The accumulated power is the power accumulated from the time of the last SOC change to this moment.

[0109] to t N2 , t N3 , t N4 At this moment, the accumulated power Q tN2 , Q tN3 , Q tN4 are greater than or equal to ΔC, so t N2 , t N3 , t N4 The SOC values ​​were 23.6%, 23.7%, and 23.8%, respectively, and at t N4 moment, Q tN4 -ΔC is used as the starting value of the accumulated power at the next moment. M At this moment, the accumulated power Q tM <ΔC, so t M The SOC value at the moment remains the same as the previous moment t N4 The SOC at the moment is 23.8%, and the accumulated power at the current moment is saved as the starting value of the accumulated power when the next power change occurs.

[0110] In terms of chip computational overhead, remainder > division > multiplication > subtraction > addition. On some low-cost chips with weak computing power, especially those without hardware dividers, the division of large numbers can be a huge overhead, and this calculation method is not conducive to computational stability. This application adopts the above SOC estimation algorithm. In actual programming, only if judgments and addition and subtraction operations can be used to replace the original division operation, which greatly reduces the amount of calculation when estimating SOC, reduces the consumption of computing resources and the occupation of storage space (in actual applications, some low-end 8-bit, 5-16K Flash chips can be used), greatly reduces the requirements for chip computing power and peripheral resources, reduces device energy consumption, increases SOC estimation speed and improves computational stability.

[0111] In some embodiments, at the end stage of charging and discharging of the mobile power supply, the SOC value obtained in step S04 is further corrected.

[0112] According to the terminal voltage characteristics of lithium iron phosphate charging and discharging, the battery voltage will show a trend of rapid rise and fall during the full charge and full discharge stages. Therefore, the SOC is corrected at the end of the charge and discharge stages.

[0113] For example: according to the battery characteristics, set a voltage threshold U corresponding to the charging terminal up And the voltage threshold U corresponding to the discharge end de ;

[0114] When the voltage U of the mobile power supply is U up ~U de When the SOC of the mobile power supply is within the range, it is considered that the SOC of the mobile power supply is not full or empty, so the SOC value obtained in step S04 does not need to be corrected.

[0115] When the voltage U of the mobile power supply is greater than U up , and when SOC is not full, a correction process is introduced:

[0116] SOC′=SOC+α(UU up );

[0117] Among them, SOC' is the corrected SOC value during charging; SOC is the SOC value before correction; α is the charging correction parameter, which can be determined in actual testing.

[0118] When in the discharge process, the voltage U of the mobile power supply is less than U de , and when SOC is not empty, the correction process is introduced:

[0119] SOC"=SOC-β(U de -U);

[0120] Among them, SOC" is the SOC value after correction during discharge; SOC is the SOC value before correction; β is the discharge correction parameter, which can be determined in actual tests.

[0121] It is understandable that, in order to further improve the accuracy, the voltage thresholds U corresponding to the two charge and discharge terminals can be set according to the battery characteristics. up1 and U up2 And the voltage threshold U corresponding to the discharge end de1 and U de2 , and obtain the corresponding correction parameters α1, α2, β1, β2 through actual testing.

[0122] According to the above SOC estimation method, an experiment was conducted using a mobile power bank with a rated capacity of 5.4Ah. The battery was charged at room temperature and the SOC was estimated using the traditional ampere-hour integration method and the method described above. The comparison of the obtained SOC estimation curves is shown in the figure below. Figure 7 As shown, the accumulated electricity / rated capacity in the figure represents the ampere-hour integration method used.

[0123] from Figure 7 It can be seen that when charging, the SOC curves obtained by the two methods have a high degree of overlap, especially at the end of charging, the corrected SOC estimate value and the SOC estimation curve obtained by the ampere-hour integration method are also highly overlapped, which shows that the SOC estimation method of the present application has a high estimation accuracy.

[0124] See also Figure 8 , Figure 8 : is a structural block diagram of an SOC estimation device provided by an embodiment of the present invention, such as Figure 8 As shown, the SOC estimation device 40 includes a first calculation module 41 , a second calculation module 42 , a comparison and acquisition module 43 and a judgment loop module 44 .

[0125] The first calculation module 41 is used to calculate the fixed step power value of the mobile power supply;

[0126] The second calculation module 42 is used to sequentially step and superimpose unit power to calculate the cumulative power of the mobile power supply since the last SOC change;

[0127] The comparison and acquisition module 43 is used to compare the absolute value of the accumulated power with the fixed step power value, and perform addition and subtraction operations based on the comparison result to obtain the SOC value at the current moment and the starting value of the accumulated power at the next moment;

[0128] The judgment loop module 44 is used to judge whether the accumulated power continues to change after the SOC value is updated. When the accumulated power continues to change, the above steps S02-S03 are looped; when the accumulated power no longer changes, the SOC value at the previous moment is maintained and the accumulated power at the current moment is saved.

[0129] It should be noted that the above-mentioned SOC estimation device can execute the SOC estimation method provided in the embodiment of the present invention and has the corresponding functional modules and beneficial effects of the execution method. For technical details not fully described in the embodiment of the SOC estimation device, please refer to the SOC estimation method provided in the embodiment of the present invention.

[0130] The present application also provides a non-volatile computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, which are executed by one or more processors, for example, to execute the above-described Figure 3 and Figure 4 Method steps to achieve Figure 8 The functions of each module in .

[0131] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of this embodiment.

[0132] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a general hardware platform, or of course by hardware. Those skilled in the art can understand that all or part of the processes in the above embodiment methods can be implemented by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above methods. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc.

[0133] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Under the idea of ​​the present invention, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the present invention as described above. For the sake of simplicity, they are not provided in detail. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of this application.

Claims

1. A SOC estimation method, applied to a mobile power supply, characterized in that: The method comprises: Step S1. Calculating the fixed-step power value of the mobile power supply; Step S2. Step by step, superimpose the unit power in sequence to calculate the cumulative power of the mobile power supply from the last SOC change moment; Step S3. Compare the absolute value of the accumulated power with the fixed step power value, and perform addition and subtraction operations based on the comparison result to obtain the SOC value at the current moment and the starting value of the accumulated power at the next moment; Step S4. After the SOC value is updated, if the accumulated power continues to change, repeat steps S2-S3; if the accumulated power no longer changes, keep the SOC value at the previous moment and save the accumulated power at the current moment; Wherein, the step S2 includes: calculating the unit power according to a second formula; the second formula is: ； Where ΔQ n The unit power refers to the unit power within a certain SOC calculation cycle T2; I n1 , I n2 ,…, I nk is the sampling current in the nth SOC calculation cycle, n1, n2, …, nk are the sampling times in the nth SOC calculation cycle, and T2 is the SOC calculation cycle; and ; j is a positive integer, T1 is the sampling period; Wherein, the step S3 includes: When the absolute value of the accumulated power is greater than or equal to the power value of the fixed step, the fixed step is added or subtracted from the SOC value at the previous moment according to the charge and discharge state of the mobile power supply as the current SOC value, and the power value of the accumulated power minus or added with the fixed step is used as the starting value of the accumulated power at the next moment; When the absolute value of the accumulated power is less than the power value of the fixed step, the SOC value at the previous moment is maintained as the current SOC value, and the accumulated power is saved as the starting value of the accumulated power at the next moment.

2. The method according to claim 1, characterized in that The step S1 comprises: The fixed-step power value of the mobile power supply is obtained according to a first formula; wherein the first formula is: and ; Wherein, ΔC is the power value of the fixed step, C is the rated capacity of the battery of the mobile power supply, P is the fixed step, λ is the proportional coefficient that changes with the ambient temperature, I max It is the maximum overcurrent value that the mobile power supply can withstand under extreme conditions.

3. The method according to claim 1, characterized in that The step S2 comprises: The accumulated power of the mobile power supply since the last SOC change is calculated according to a third formula; wherein the third formula is: ； Among them, Q st Indicates the starting value of the accumulated power, N is a positive integer.

4. The method according to claim 1, wherein The method further includes correcting the current SOC value obtained in step S3 at the end of charging and discharging of the mobile power supply.

5. The method according to claim 4, characterized in that The step of correcting the SOC of the mobile power supply at the end of the charge and discharge phase of the mobile power supply includes: During the charging process of the mobile power supply, if the voltage U of the mobile power supply is greater than the charging terminal voltage threshold U up , and when the SOC value of the mobile power supply is not fully charged, a correction process is introduced: ； Among them, SOC' is the corrected SOC value during charging; SOC is the SOC value before correction; α is the charging correction parameter.

6. The method according to claim 4, characterized in that The step of correcting the SOC of the mobile power supply at the end of the charge and discharge phase of the mobile power supply includes: During the discharge process of the mobile power supply, if the voltage U of the mobile power supply is less than the discharge end voltage threshold U de , and when the SOC value of the mobile power supply is not empty, a correction process is introduced: ； Among them, SOC" is the SOC value after correction during discharge; SOC is the SOC value before correction; β is the discharge correction parameter.

7. A mobile power supply, characterized in that: The mobile power supply comprises: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method according to any one of claims 1 to 6.

8. A readable storage medium, characterized in that: The readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the method according to any one of claims 1 to 6.

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