Balancing method, balancing system and computer readable storage medium
By performing parallel discharging of the battery box, voltage difference and battery cell voltage difference are balanced in steps, the capacity reduction and life reduction caused by voltage difference in the battery pack is solved, and efficient and low-cost battery equalization is achieved.
Patent Information
- Application Number
- CN202510449260.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-10
- Publication Date
- 2025-07-11
AI Technical Summary
Excessive voltage difference in existing battery packs or battery clusters leads to reduced capacity and service life, and existing equalization devices are complex and inefficient in connection.
By discharging the battery box to a preset power threshold, parallel equalization is performed using the potential difference between the battery cells, and it is divided into two steps to equalize the voltage difference and the voltage difference between the battery cells, reducing the use of the connecting device.
The equalization process is simplified, the equalization efficiency and accuracy of the battery pack are improved, and the cost and connection complexity are reduced.
Smart Images
Figure CN120300982A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of batteries, and in particular, to an equalization method, an equalization system, and a computer-readable storage medium. Background Art
[0002] During the use of a battery pack or a battery cluster, there will be a certain voltage difference due to reasons such as structure. When the voltage difference is too large, it will not only cause a reduction in the capacity of the battery pack or battery cluster, but also lead to a decrease in its service life.
[0003] In the prior art, in order to solve the problem of too large voltage difference, usually, the voltage difference is equalized by an equalization device provided inside a Battery Management System (BMS), which usually includes two equalization methods: active equalization and passive equalization.
[0004] However, when the above equalization device is used, since the voltage difference is formed between each battery cell, when equalizing, the equalization device needs to be connected to each battery cell separately. This results in a complex connection and equalization process during the equalization of the battery pack, and the overall equalization efficiency is low.
[0005] Therefore, there is an urgent need to provide a battery equalization device or an equalization method to simplify the equalization process and thereby improve the equalization efficiency of the battery pack. Summary of the Invention
[0006] The purpose of the present application is to provide an equalization method, an equalization system, and a computer-readable storage medium, which can simplify the equalization process and thereby improve the equalization efficiency of the battery pack.
[0007] To achieve the above purpose, in the first aspect of the present application, the present application provides an equalization method, which includes the following steps: discharging the battery box to an empty state. The battery box includes a first battery pack and a second battery pack connected in parallel. The first battery pack and the second battery pack each include M battery cells (M≥2) connected in series. The empty state includes: the remaining power of the first battery pack and the second battery pack is equal to a preset power threshold. Performing voltage equalization between the first battery pack and the second battery pack, including: connecting the i-th battery cell of the first battery pack in parallel with the i-th battery cell of the second battery pack until the absolute value of the difference between the voltage V 1i of the i-th battery cell of the first battery pack and the voltage V 2i of the i-th battery cell of the second battery pack is less than a first difference threshold. Wherein, i is any one of M. Performing voltage equalization within the battery pack, including: connecting the M battery cells of the first battery pack in parallel, and / or connecting the M battery cells of the second battery pack in parallel, until the absolute value of the voltage difference between any two battery cells among the M battery cells of each battery pack is less than a second difference threshold.
[0008] Based on the above embodiments of the present application, when starting the balancing, first, the remaining State of Charge (SOC) of the battery box is discharged to a preset power threshold by discharging, so as to avoid the platform voltage of the battery pack, so as to better balance the voltage difference of the battery pack. Subsequently, the voltage between the first battery pack and the second battery pack is balanced in a parallel manner. Specifically, the battery cells at the same position in the first battery pack and the second battery pack are respectively connected in parallel, and the potential difference between the battery cells is used to drive the movement of charges, and then a current is formed between the two battery cells with a voltage difference until the voltage difference between the battery cells at the same position in the first battery pack and the second battery pack is less than the first difference threshold. Subsequently, the voltage difference inside the first battery pack and the second battery pack is balanced. Specifically, the battery cells inside the first battery pack are connected in parallel, and the potential difference between the battery cells is also used to form a current between the battery cells, and finally the voltage difference between the battery cells is less than the second difference threshold. The multiple battery cells inside the second battery pack are also balanced in a parallel manner. The overall balancing process is divided into two steps. After the first step of balancing, the voltage difference between the battery cells of the battery pack is limited to be less than the first difference threshold, and then after the second step of balancing, the voltage difference between the battery cells is further limited to be less than the second difference threshold. Thus, through two-step balancing processing, the balancing accuracy is improved.
[0009] In some embodiments, the first difference threshold is greater than the second difference threshold.
[0010] Based on the above embodiments of the present application, during the process of balancing the voltage difference of the battery box, first, the voltage difference between the corresponding battery cells of the first battery pack and the second battery pack is limited within the first difference threshold in a parallel manner, and then the voltage difference between each battery cell inside the first battery pack and the second battery pack is limited within the second difference threshold in a parallel manner. By setting the second difference threshold to be less than the first difference threshold, that is, during the first step of balancing, the voltage difference between the first battery pack and the second battery pack is initially limited, and at this time, the balanced voltage difference is relatively large. Subsequently, after the second step of balancing, the voltage difference between the battery cells is further balanced, and then the voltage difference between the battery cells is balanced to a smaller range. Through two-step balancing processing, the balancing accuracy is improved.
[0011] In some embodiments, the preset power threshold includes: 20%, 10% or 0.
[0012] Based on the above embodiments of the present application, when balancing the battery box, by first discharging the battery box until the remaining power reaches the preset power threshold, the platform voltage of the battery pack is avoided, so as to better balance the voltage difference of the battery pack. And the specific preset power threshold can be set to different ratios according to different factors such as battery types, and can specifically be selected as any one of the specific ratios of 20%, 10% or 0.
[0013] In some embodiments, paralleling the i-th battery cell of the first battery pack with the i-th battery cell of the second battery pack includes paralleling the i-th battery cell of the first battery pack with the i-th battery cell of the second battery pack through a wire.
[0014] Based on the above embodiments of the present application, the battery cells at corresponding positions in the first battery pack and the second battery pack are paralleled by means of wire connection. At this time, there is no need to connect the balancing device, which can not only simplify the connection process, but also reduce the balancing cost.
[0015] In some embodiments, paralleling M battery cells of the first battery pack and / or the second battery pack respectively includes: paralleling M battery cells of the first battery pack and / or the second battery pack respectively through a balancing board.
[0016] Based on the above embodiments of the present application, multiple battery cells inside the first battery pack and the second battery pack are paralleled respectively through a balancing board. At this time, while achieving natural balance through the potential difference between the battery cells, the balancing board can also be used to balance the battery cells, further improving the accuracy of battery box balancing. Further, since the battery cells at corresponding positions inside the first battery pack and the second battery pack have been paralleled at this time, it is not necessary to parallel all the battery cells in the first battery pack and the second battery pack with the balancing board, thus simplifying the connection process and improving the balancing efficiency.
[0017] In some embodiments, before performing voltage balancing between the first battery pack and the second battery pack, the balancing method further includes: disconnecting the series connection between M battery cells of each battery pack.
[0018] Based on the above embodiments of the present application, by disconnecting the series connection between the individual battery cells in the battery pack, the individual battery cells become independent of each other, so that when performing voltage balancing between the first battery pack and the second battery pack, each battery cell can better utilize the potential difference to drive the completion of the balancing process.
[0019] In some embodiments, after performing voltage balancing inside the battery pack, the balancing method further includes leaving the battery box static for a preset time.
[0020] Based on the above embodiments of the present application, since current will be generated during the process of differential pressure balancing of the battery pack, it will cause potential changes between the modules, and thus polarization will occur. When the battery pack is polarized, it will have an impact on both the capacity and the charge and discharge efficiency. Therefore, the polarization of the battery pack is eliminated by means of static placement, etc., to reduce the impact on the battery pack in terms of capacity, charge and discharge efficiency, etc.
[0021] According to the second aspect of the present application, there is provided a balancing system, which includes a processor and a memory. A computer program that can run on the processor is stored on the memory. Among them, when the computer program is executed by the processor, the above-mentioned balancing method is implemented.
[0022] Based on the above embodiments of the present application, the balancing system provided by the present application can implement the above-mentioned balancing method, and further achieve the corresponding beneficial effects through the above-mentioned balancing method. To avoid repetition, it will not be elaborated here.
[0023] According to the third aspect of the present application, there is provided a computer-readable storage medium. A data processing program is stored on the computer-readable storage medium. When the data processing program is executed by the processor, the steps of the above-mentioned balancing method are implemented.
[0024] Based on the above embodiments of the present application, the data processing program stored in the computer-readable storage medium provided by the present application can implement the above-mentioned balancing method when executed. Through this balancing method, the above-mentioned beneficial effects can be achieved. To avoid repetition, it will not be elaborated here.
[0025] Other features and advantages of the present application will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The drawings are used to provide a further understanding of the present application, and constitute a part of the specification. Together with the following specific implementation, they are used to explain the present application, but do not constitute a limitation to the present application. In the drawings:
[0027] Figure 1 is a schematic diagram of the steps of the balancing method provided by the embodiment of the present application.
[0028] Figure 2 is a schematic diagram of the structures of the first battery pack and the second battery pack in the balancing method provided by the embodiment of the present application.
[0029] Figure 3 is a schematic diagram of the structure of the first battery pack in the balancing method provided by the embodiment of the present application.
[0030] Figure 4 is a schematic diagram of the structures of the first battery pack, the second battery pack, and the third battery pack in the balancing method provided by the embodiment of the present application.
[0031] Figure 5 is another schematic diagram of the structures of the first battery pack, the second battery pack, and the third battery pack in the balancing method provided by the embodiment of the present application.
[0032] DESCRIPTION OF THE REFERENCE NUMERALS
[0033] 11. First battery pack; 12. Second battery pack; 13. Third battery pack; 2. Battery cell; 21. Battery cell 1a; 22. Battery cell 2a; 23. Battery cell 12a; 24. Battery cell 1b; 25. Battery cell 2b; 26. Battery cell 12b; 27. Battery cell 1c; 28. Battery cell 2c; 29. Battery cell 12c; 3. Balancing board; 4. First connecting wire; 5. Second connecting wire. Detailed implementation manners
[0034] In order to make the objectives, technical solutions and advantages of the present application clearer and more understandable, the present application 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 application and are not used to limit the present application.
[0035] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. Usually, the components of the embodiments of the present application described and illustrated in the accompanying drawings herein can be arranged and designed in various different configurations.
[0036] Therefore, the detailed description of the embodiments of the present application provided in the accompanying drawings below is not intended to limit the scope of the present application claimed, but merely represents the selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts fall within the scope of protection of the present application.
[0037] It should be noted that similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.
[0038] In the description of the present application, it should be noted that unless otherwise stated, the orientation or positional relationship indicated by terms such as "inside", "outside", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the present application is usually placed during use. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present application. In addition, terms such as "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.
[0039] In the description of the present application, it should also be noted that, unless otherwise clearly specified and defined, the terms "arrangement" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.
[0040] In the prior art, in order to solve the problem of excessive voltage difference when using a battery pack or a battery cluster, usually an equalization device provided inside a Battery Management System (BMS) is used to perform equalization processing on the voltage difference, which generally includes two equalization methods: active equalization and passive equalization.
[0041] However, when the above equalization device is used, since there are voltage differences formed between all voltages, therefore, each battery cell needs to be connected to the equalization device during specific equalization. At this time, the overall connection process is cumbersome and complex, resulting in a relatively low overall equalization efficiency. Further, when performing equalization processing in the above manner, due to the limited number of channels of the equalization device itself, for example, usually four channels, and each channel can usually connect and equalize twelve strings of battery cells, the number of battery cells that the equalization device can equalize and process at one time is relatively limited. Therefore, when the number of battery cells that need to be equalized and processed at one time is large, usually multiple equalization devices need to be purchased. At the same time, the circuit design and control algorithm of the equalization device are relatively complex, which not only increases the cost of the equalization device, but also increases its failure rate and affects the reliability during equalization.
[0042] The battery box includes a first battery pack 11 and a second battery pack 12 connected in parallel, and the first battery pack 11 and the second battery pack 12 each include M battery cells 2 connected in series (M≥2). To solve the above technical problems in the present application, an embodiment of the present application provides an equalization method. Referring to Figure 1 as shown, the equalization method includes the following steps: discharging the battery box to an empty state, performing voltage equalization between the first battery pack and the second battery pack, and then performing voltage equalization within the battery pack.
[0043] Before equalizing the battery box, it is discharged to an empty state to avoid the plateau voltage of the battery pack, so as to better equalize the voltage difference of the battery pack and ensure that the equalization operation is more effective. Among them, the empty state includes: the remaining power of the first battery pack 11 and the second battery pack 12 is equal to a preset power threshold.
[0044] Performing voltage equalization between the first battery pack 11 and the second battery pack 12 as described above includes: paralleling the i-th battery cell 2 of the first battery pack 11 with the i-th battery cell 2 of the second battery pack 12 until the absolute value of the difference between the voltage V 1i of the i-th battery cell 2 of the first battery pack 11 and the voltage V 2i of the i-th battery cell 2 of the second battery pack 12 is less than a first difference threshold. Wherein, i is any one in M.
[0045] When the absolute value of the voltage difference between the battery cells at the same position of the first battery pack 11 and the second battery pack 12 is less than the first difference threshold, voltage equalization within the battery pack is performed, including: paralleling the M battery cells 2 of the first battery pack 11 and / or paralleling the M battery cells 2 of the second battery pack 12 until the absolute value of the voltage difference between any two of the M battery cells 2 in each battery pack is less than a second difference threshold.
[0046] First, the pressure difference equalization between the first battery pack 11 and the second battery pack 12 is performed, and then the pressure difference equalization between the M battery cells within the battery pack is performed, thereby improving the overall equalization efficiency and equalization accuracy.
[0047] Optionally, the preset power threshold SOC can be 20%, 10% or 0.
[0048] Optionally, the i-th battery cell of the first battery pack is paralleled with the i-th battery cell of the second battery pack through a wire.
[0049] Optionally, the first difference threshold is greater than, less than or equal to the second difference threshold. Preferably, the first difference threshold is greater than the second difference threshold.
[0050] Based on the above embodiments of the present application, when starting equalization, first, the remaining power (State Of Charge, SOC) of the battery box is discharged to the preset power threshold by discharging, so as to avoid the plateau voltage of the battery pack, so as to better equalize the pressure difference of the battery pack. Subsequently, the voltage between the first battery pack 11 and the second battery pack 12 is equalized by paralleling. Specifically, the battery cells 2 at the same position in the first battery pack 11 and the second battery pack 12 are respectively paralleled, and the potential difference between the battery cells 2 is used to drive the movement of charges, and then a current is formed between the two battery cells 2 with a pressure difference until the pressure difference between the battery cells 2 at the same position in the first battery pack 11 and the second battery pack 12 is less than the first difference threshold.
[0051] Subsequently, the voltage differences inside the first battery pack 11 and the second battery pack 12 are equalized. Specifically, the battery cells 2 inside the first battery pack 11 are connected in parallel. Similarly, the potential difference between the battery cells 2 is used to form a current between the battery cells 2, and finally the voltage difference between the battery cells 2 is made less than the second difference threshold. The multiple battery cells 2 inside the second battery pack 12 are also equalized in a parallel connection manner.
[0052] With the above settings, first, the voltage difference between the first battery pack 11 and the second battery pack 12 is equalized by a parallel connection method. In this process, only the battery cells 2 inside each first battery pack 11 and the second battery pack 12 need to be correspondingly connected in parallel through connection structures such as wires. Compared with the equalization devices in the prior art, the equalization cost is significantly reduced. At the same time, when equalizing the voltages inside the first battery pack 11 and the second battery pack 12, the battery cells 2 are also connected through connection structures such as wires.
[0053] In summary, referring to Figure 2 and Figure 3 as shown, with the above settings, the battery cells 2 are directly connected by wires, and the equalization is naturally achieved by using the voltage differences between the battery cells 2, eliminating the process of connecting the equalization device, simplifying the voltage equalization process, thereby improving the equalization efficiency and reducing the equalization cost at the same time. Further, the overall equalization process is divided into two steps. After the first step of equalization, the voltage difference between the battery cells 2 in the battery pack is limited to be less than the first difference threshold, and then after the second step of equalization, the voltage difference between the battery cells 2 is further limited to be less than the second difference threshold. Thus, through two-step equalization processing, the equalization accuracy is improved.
[0054] Specifically, when equalizing the voltage differences inside the battery pack in this application, since the battery cells 2 at the same positions in the first battery pack and the second battery pack 12 still remain connected in parallel, the voltage differences between the corresponding battery cells 2 can continue to be equalized. Accordingly, when the voltage differences between the multiple battery cells 2 in the first battery pack 11 are equalized, the voltage differences between the multiple battery cells 2 in the second battery pack 12 will also be equalized. Similarly, when the voltage differences between the multiple battery cells 2 in the second battery pack 12 are equalized, the voltage differences between the multiple battery cells 2 in the first battery pack 11 will also be equalized. Therefore, when connecting, only the M battery cells 2 inside the first battery pack 11 can be connected in parallel, or only the M battery cells 2 inside the second battery pack 12 can be connected in parallel, thereby further simplifying the connection process. Or, the M battery cells 2 inside the first battery pack 11 can be connected in parallel while the M battery cells 2 inside the second battery pack 12 are connected in parallel. It can be specifically set according to the actual situation, and this application does not make specific limitations on this.
[0055] In addition, it should be noted that the above embodiments of the present application only limit the balancing scheme of two battery packs, namely the first battery pack 11 and the second battery pack 12, provided in the battery box. When the number of battery packs is three, four, or even more, the above balancing method can also be applied to balance the pressure difference inside the battery box.
[0056] Specifically, taking the example of a battery box including three battery packs, namely the first battery pack 11, the second battery pack 12, and the third battery pack 13 connected in parallel. At the beginning of the balancing, the battery box is also discharged until it is completely empty. Subsequently, the pressure difference between the three battery packs is balanced. The i-th battery cell 2 of the first battery pack 11, the i-th battery cell 2 of the second battery pack 12, and the i-th battery cell 2 of the third battery pack 13 are simultaneously connected in parallel until the absolute value of the difference between any two of the voltages V 1i of the i-th battery cell 2 of the first battery pack 11, V 2i of the i-th battery cell 2 of the second battery pack 12, and V 3i of the i-th battery cell 2 of the third battery pack 13 is less than the first difference threshold.
[0057] Finally, the pressure differences inside the three battery packs are balanced respectively. At this time, since the battery cells 2 at the corresponding positions in the first battery pack 11, the second battery pack 12, and the third battery pack 13 still maintain parallel connection and balancing, therefore, when connecting, the battery cells 2 in the first battery pack 11, the second battery pack 12, and the third battery pack 13 can all be connected in parallel respectively, or only the battery cells 2 inside any one or two of the first battery pack 11, the second battery pack 12, and the third battery pack 13 can be connected in parallel, thus simplifying the wiring process and further improving the balancing efficiency.
[0058] Similarly, when the number of battery packs in the battery box further increases, the pressure difference inside the battery box can also be balanced by the above balancing method, and specific settings can be made according to the actual situation. The present application does not make specific limitations on this.
[0059] In some embodiments of the present application, the first difference threshold can be greater than the second difference threshold.
[0060] Based on the above embodiments of the present application, during the process of balancing the pressure difference of the battery box, first, the pressure difference between the corresponding battery cells 2 between the first battery pack 11 and the second battery pack 12 is restricted within the first difference threshold in a parallel connection manner, and then the pressure difference between each battery cell 2 inside the first battery pack 11 and the second battery pack 12 is restricted within the second difference threshold in a parallel connection manner. By setting the second difference threshold to be less than the first difference threshold, that is, in the first step of balancing, the pressure difference between the first battery pack 11 and the second battery pack 12 is initially restricted, and at this time, the balanced pressure difference is relatively large. Subsequently, through the second step of balancing, the pressure difference between the battery cells 2 is further balanced, and thus the pressure difference between the battery cells 2 is balanced to a smaller range. Through the two-step balancing process, the balancing accuracy is improved.
[0061] Or, in some other embodiments of the present application, the first difference threshold may also be less than or equal to the second difference threshold. When the first difference threshold is less than the second difference threshold, at this time, the pressure difference between different battery packs can be balanced to be relatively small, while the pressure difference between each battery cell 2 inside the battery pack is relatively large. When the first difference threshold is equal to the second difference threshold, at this time, the pressure difference between the battery packs and the pressure difference inside the battery packs can be controlled within a more appropriate range. It can be specifically set according to the actual situation, and the present application does not make specific restrictions on this.
[0062] Furthermore, the specific values of the first difference threshold and the second difference threshold can be set according to the actual situation. For example, in some embodiments of the present application, the first difference threshold and the second difference threshold can be specifically set to 3 mv. At this time, after the two-step balancing process, the pressure difference between the battery cells 2 can be controlled within 3 mv. It can be specifically set according to the actual use requirements of the battery box, etc., and the present application does not make specific restrictions on this.
[0063] In the present application, the preset power threshold can be specifically set to any appropriate ratio. In some embodiments of the present application, the preset power threshold may include: 20%, 10% or 0.
[0064] Based on the above embodiments of the present application, when balancing the battery box, by first discharging the battery box until the remaining power reaches the preset power threshold, the platform voltage of the battery pack can be avoided, so as to better balance the pressure difference of the battery pack. And the specific preset power threshold can be set to different ratios according to factors such as different battery types, and any specific ratio among 20%, 10% or 0 can be specifically selected.
[0065] Specifically, before starting the differential pressure equalization process, the battery box is discharged to reduce the voltage of the battery cell 2 to the lowest value. For example, the voltage of a lithium iron phosphate battery can be reduced to about 2.5V. On the one hand, this avoids the platform voltage, and on the other hand, it increases the voltage difference between the battery cells 2, reduces the influence of other factors on the differential pressure, and enables better differential pressure equalization.
[0066] In some embodiments of the present application, the i-th battery cell 2 of the first battery pack 11 is connected in parallel with the i-th battery cell 2 of the second battery pack 12, including connecting the i-th battery cell 2 of the first battery pack 11 and the i-th battery cell 2 of the second battery pack 12 in parallel through a wire.
[0067] Based on the above embodiments of the present application, the battery cells 2 at corresponding positions in the first battery pack 11 and the second battery pack 12 are connected in parallel by wire connection. At this time, there is no need to connect an equalization device, which can not only simplify the connection process but also reduce the equalization cost.
[0068] Specifically, in some embodiments of the present application, the i-th battery cell 2 in the first battery pack 11 and the i-th battery cell 2 in the second battery pack 12 can be connected in parallel through a first connecting wire 4.
[0069] Refer to Figure 2 and Figure 3 As shown in, in some embodiments of the present application, each battery cell 2 can be provided with a positive electrode terminal and a negative electrode terminal. For the battery cells 2 in one battery pack, the positive electrode terminals of the battery cells 2 at the same position are connected to the positive electrode terminals of the battery cells 2 at the same position in another battery pack through the first connecting wire 4, and the negative electrode terminals are connected to the negative electrode terminals of the battery cells 2 at the same position in another battery pack through the first connecting wire 4. For example, the positive electrode terminal of the second battery cell 2 in the first battery pack 11 is connected to the positive electrode terminal of the second battery cell 2 in the second battery pack 12 through the first connecting wire 4, and then the negative electrode terminal of the second battery cell 2 in the first battery pack 11 is connected to the negative electrode terminal of the second battery cell 2 in the second battery pack 12 through the first connecting wire 4, thereby realizing the parallel connection between the second battery cell 2 in the first battery pack 11 and the second battery cell 2 in the second battery pack 12.
[0070] Meanwhile, in some other embodiments of the present application, refer to Figure 4 and Figure 5 As shown in, when the number of battery packs is three, four or more, the battery cells 2 at the same position in multiple battery packs can also be connected in parallel through the first connecting wire 4.
[0071] Furthermore, in some embodiments of the present application, a wire clip can be provided at the end of the first connecting wire 4, and the wire clip directly clamps on the positive electrode terminal and the negative electrode terminal of the battery cell 2, thereby realizing a fast and stable connection, simplifying the wiring process, and reducing the wiring cost at the same time.
[0072] In some embodiments of the present application, M battery cells 2 of the first battery pack 11 and / or the second battery pack 12 are respectively connected in parallel, including: connecting M battery cells 2 of the first battery pack 11 and / or the second battery pack 12 in parallel through an equalizing board 3.
[0073] Based on the above embodiments of the present application, a plurality of battery cells 2 inside the first battery pack 11 and the second battery pack 12 are respectively connected in parallel through the equalizing board 3. At this time, while achieving natural equalization through the potential difference between the battery cells 2, the equalizing board 3 can also be used to equalize the battery cells 2, further improving the accuracy of battery box equalization. Further, since the battery cells 2 at corresponding positions inside the first battery pack 11 and the second battery pack 12 are already connected in parallel at this time, therefore, it is not necessary to connect all the battery cells 2 in the first battery pack 11 and the second battery pack 12 to the equalizing board 3, thus simplifying the connection process and improving the equalization efficiency.
[0074] Specifically, when in use, the equalizing board 3 is directly connected to the battery cells 2. In principle, the equalizing board 3 can be specifically divided into two types: active equalization and passive equalization. Among them, passive equalization is to consume the excess energy in the form of heat by connecting a resistor in parallel with the battery cell 2 to achieve voltage equalization. Active equalization is to use energy storage elements such as inductors and capacitors to transfer the electric charge from the battery cell 2 with a higher voltage to the battery cell 2 with a lower voltage to achieve re - distribution of energy. In the present application, any suitable structure of the equalizing board 3 can be selected. Since the present application does not involve the improvement of the specific structure of the equalizing board 3, no specific limitation is made here.
[0075] Further, in some embodiments of the present application, as shown in Figure 4 a second connecting wire 5 can also be connected between the battery cell 2 and the equalizing board 3. By connecting the battery cell 2 and the equalizing board 3 through the second connecting wire 5, the equalizing effect on the battery cell 2 is further enhanced by using the equalizing board 3.
[0076] In some embodiments of the present application, before performing voltage equalization between the first battery pack 11 and the second battery pack 12, the equalization method further includes: disconnecting the series connection between the M battery cells 2 of each battery pack.
[0077] Based on the above embodiments of the present application, by disconnecting the series connection between the respective battery cells 2 in the battery pack, each battery cell 2 becomes independent of each other. Further, when performing voltage equalization between the first battery pack 11 and the second battery pack 12, each battery cell 2 can better utilize the potential difference to promote the equalization process.
[0078] In some embodiments of the present application, after performing voltage equalization inside the battery pack, the equalization method further includes leaving the battery box static for a preset time.
[0079] Based on the above embodiments of the present application, since current will be generated during the voltage difference equalization process of the battery pack, it will cause potential changes between the modules, and then polarization will occur. When the battery pack polarizes, it will affect both the capacity and the charge and discharge efficiency. Therefore, the polarization of the battery pack is eliminated by means such as standing still to reduce the impact on aspects such as the capacity and charge and discharge efficiency of the battery pack.
[0080] Specifically, in the present application, the above-mentioned solution for eliminating the polarization of the battery pack by standing still is provided. In actual use, the polarization of the battery pack can be eliminated by any suitable method. For example, by improving the electrolyte and electrode materials, selecting a more conductive electrolyte or a higher activity electrode material to improve the conduction ability of ions and electrons, thereby reducing polarization. Or, by increasing the surface area of the electrode, using porous materials or coating techniques to increase the surface area of the electrode, thereby increasing the reaction rate and achieving the effect of reducing polarization. Or, it can also be achieved by optimizing the battery structure. By changing the battery structure, such as increasing the contact area between the electrode and the electrolyte, the impedance of ion migration is reduced, and thus the effect of reducing polarization is achieved.
[0081] At the same time, in some technical solutions of the present application, when adopting the technical solution of eliminating the polarization of the battery pack by standing still, specific standing time and the like can be set in any suitable way. For example, the standing time can be specifically set to 3 days to 6 days. Specifically, it can be set according to the polarization degree of the battery cell 2. Since the present application does not involve the improvement of the specific method for eliminating the polarization of the battery pack, no specific limitation is made here.
[0082] In summary, referring to Figure 4 and Figure 5 as shown in, the equalization method of the present application specifically includes the following process. Taking the setting of three battery packs, namely the first battery pack 11, the second battery pack 12, and the third battery pack 13, and each battery pack is provided with twelve battery cells 2 as an example.
[0083] The twelve battery cells 2 in the first battery pack 11 are sequentially named battery cell 1a21, battery cell 2a22 until battery cell 12a23. Similarly, the twelve battery cells 2 in the second battery pack 12 are sequentially named battery cell 1b24, battery cell 2b25 until battery cell 12b26, and the twelve battery cells 2 in the third battery pack 13 are sequentially named battery cell 1c27, battery cell 2c28 until battery cell 12c29.
[0084] When performing balancing processing, first, the battery cells 2 at the same position inside each battery pack 1 are connected in parallel. Through the first connecting line, the battery cells 1a21, 1b24, and 1c27 are connected in parallel with each other, the battery cells 2a22, 2b25, and 2c28 are connected in parallel with each other, until the battery cells 12a23, 12b26, and 12c29 are connected in parallel with each other. At this time, the voltage difference between the battery cells 1a21, 1b24, and 1c27 is limited within the first difference threshold through the parallel connection method, the voltage difference between the battery cells 2a22, 2b25, and 2c28 is limited within the first difference threshold through the parallel connection method, until the voltage difference between the battery cells 12a23, 12b26, and 12c29 is limited within the first difference threshold through the parallel connection method.
[0085] Subsequently, the voltages inside each battery pack are balanced. Specifically, the battery cells 1a21, 2a22, until the battery cell 12a23 inside the first battery pack 11 are connected in parallel until the absolute value of the voltage difference between each battery cell 2 is less than the second difference threshold. Alternatively, the twelve battery cells 2 inside the second battery pack 12 or the third battery pack 13 can also be connected in parallel.
[0086] Finally, the balancing board 3 is connected to each unit battery to balance the voltage difference between different battery cells 2 in the same battery pack 1. It is necessary to balance the voltage difference between the battery cells 1a21, 2a22, until the battery cell 12a23 in the first battery pack 11. At this time, the battery cells 1a21, 2a22, until the battery cell 12a23 are respectively connected to the balancing board 3 through the second connecting line 5. When balancing the voltage difference between the battery cells 1b24, 2b25, until the battery cell 12b26 in the second battery pack 12, the battery cells 1b24, 2b25, until the battery cell 12b26 are respectively connected to the balancing board 3 through the second connecting line 5. When balancing the voltage difference between the battery cells 1c27, 2c28, until the battery cell 12c29 in the third battery pack 13, the battery cells 1c27, 2c28, until the battery cell 12c29 are respectively connected to the balancing board 3 through the second connecting line 5. That is, a total of thirty-six battery cells 2 in the three battery packs 1 need to be connected to the balancing board 3.
[0087] However, since the battery cells 1a21, 1b24, and 1c27 are already connected in parallel, when one of the three is connected to the equalization board 3 through the second connection line 5, the other two battery cells 2 are also indirectly connected to the equalization board 3. Similarly, for the battery cells 2a22, 2b25, and 2c28, only one of them needs to be directly connected to the equalization board 3 through the second connection line 5, until only one of the battery cells 2 among the battery cells 12a23, 12b26, and 12c29 needs to be directly connected to the equalization board 3 through the second connection line 5.
[0088] When specifically connecting, one can choose only one battery cell 2 in one battery pack 1 to be directly connected to the equalization board 3 through the second connection line 5. For example, the battery cells 1a21, 2a22, until 12a23 are respectively connected to the equalization board 3 through the second connection line 5. Or, one can also choose one battery cell 2 at each position in the battery pack 1 to be connected to the equalization board 3 through the second connection line 5. For example, at the first position, choose the battery cell 1a21 to be connected to the equalization board 3, at the second position, choose the battery cell 2c28 to be connected to the equalization board 3, until the twelfth position, choose the battery cell 12c29 to be connected to the equalization board 3. The specific connection method can be set according to wiring requirements, etc., and the present application does not make specific restrictions on this.
[0089] Through the above settings, the number of interfaces required for the equalization board 3 can be reduced. For example, still taking three battery packs 1 with a total of thirty-six battery cells 2 as an example, originally thirty-six interfaces should be required to achieve the voltage difference equalization among all the battery cells 2. However, through the above settings of the present application, the number of required interfaces can be reduced to twelve. And when the number of battery packs 1 increases, this technical effect in the present application will be more significant. In summary, through the above settings of the present application, the number of required equalization boards 3 can be saved, and the equalization processing cost can be reduced.
[0090] In addition, it should also be noted that the above in the present application only takes three battery packs 1 with a total of thirty-six battery cells 2 as an example to illustrate the wiring connection method during equalization processing. In actual applications, both the number of battery packs 1 and the number of battery cells 2 in a single battery pack 1 can be set to any suitable values, and the present application does not make specific restrictions on this.
[0091] Based on the above technical solution, according to the second aspect of the present application, an equalization system is provided. The equalization system includes a processor and a memory. A computer program that can run on the processor is stored on the memory. Among them, when the computer program is executed by the processor, the above equalization method is implemented.
[0092] Based on the above embodiments of the present application, the equalization system provided by the present application can implement the above equalization method, and thus achieve the corresponding beneficial effects through the above equalization method. To avoid repetition, it will not be elaborated here.
[0093] Based on the above technical solution, according to the third aspect of the present application, a computer-readable storage medium is provided. A data processing program is stored on the computer-readable storage medium, and when the data processing program is executed by a processor, the steps of the above-mentioned balancing method are implemented.
[0094] Based on the above embodiments of the present application, the data processing program stored in the calculator-readable storage medium provided by the present application can implement the above-mentioned balancing method when executed. Through this balancing method, the above-mentioned beneficial effects can be achieved. To avoid repetition, it will not be elaborated here.
[0095] The preferred embodiments of the present application have been described in detail above with reference to the accompanying drawings. However, the present application is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present application, various simple modifications can be made to the technical solution of the present application, and these simple modifications all fall within the protection scope of the present application.
[0096] In addition, it should be noted that, in the case of no contradiction, the various specific technical features described in the above specific embodiments can be combined in any suitable manner. To avoid unnecessary repetition, the present application will not separately describe various possible combination methods.
[0097] In addition, any combination can be made between various different embodiments of the present application, as long as it does not violate the idea of the present application, and it should also be regarded as the content disclosed by the present application.
Claims
1. An equalization method, characterized in that, The equalization method includes the following steps: Discharge the battery box until it is in an empty state. The battery box includes a first battery pack and a second battery pack connected in parallel. The first battery pack and the second battery pack each include M series-connected battery cells (M≥2). The empty state includes: the remaining power of the first battery pack and the second battery pack is equal to a preset power threshold. Performing voltage equalization between the first battery pack and the second battery pack includes: paralleling the i-th battery cell of the first battery pack with the i-th battery cell of the second battery pack until the absolute value of the difference between the voltage V 1i of the i-th battery cell of the first battery pack and the voltage V 2i of the i-th battery cell of the second battery pack is less than a first difference threshold; where i is any one of the M; Perform voltage equalization within the battery packs, including: connecting the M battery cells of the first battery pack in parallel, and / or connecting the M battery cells of the second battery pack in parallel, until the absolute value of the voltage difference between any two of the M battery cells in each battery pack is less than a second difference threshold.
2. The equalization method according to claim 1, characterized in that The first difference threshold is greater than the second difference threshold.
3. The equalization method according to claim 1 or 2, characterized in that The preset power threshold includes: 20%, 10%, or 0.
4. The equalization method according to claim 1, wherein, Connecting the i-th battery cell of the first battery pack in parallel with the i-th battery cell of the second battery pack includes connecting the i-th battery cell of the first battery pack in parallel with the i-th battery cell of the second battery pack through a wire.
5. The equalization method according to claim 1, characterized in that, Connecting the M battery cells of the first battery pack and / or the second battery pack in parallel respectively includes: connecting the M battery cells of the first battery pack and / or the second battery pack in parallel respectively through an equalization board.
6. The equalization method according to claim 1, wherein Before performing voltage equalization between the first battery pack and the second battery pack, the equalization method further includes: disconnecting the series connection between the M battery cells of each battery pack.
7. The equalization method according to claim 1, characterized in that, After performing voltage equalization within the battery packs, the equalization method further includes: Let the battery box stand for a preset time.
8. An equalization system, characterized in that, It includes: A processor and a memory; The memory stores a computer program that can run on the processor; Wherein, when the computer program is executed by the processor, it implements the equalization method according to any one of claims 1 to 7.
9. A computer-readable storage medium, characterized in that, A data processing program is stored on the computer-readable storage medium. When the data processing program is executed by the processor, it implements the steps of the equalization method according to any one of claims 1 to 7.