CN116995785B - A battery pack parallel connection method, device and system - Google Patents

Abstract

The present invention relates to the field of battery control technologies, and in particular, to a method, an apparatus, and a system for parallel connection of a battery pack. According to the method, average voltage values corresponding to a plurality of battery packs to be connected in parallel are obtained, a battery pack closest to the average voltage value is selected from the plurality of battery packs to serve as a target battery pack and a target residual battery pack closest to the voltage value of the target battery pack, the battery packs after being connected in parallel are used as the target battery pack, residual battery packs closest to the voltage value of the target battery pack are determined in a residual battery pack set which is not judged in parallel repeatedly, and the residual battery packs are connected in parallel until the parallel judgment and corresponding parallel connection of all the battery packs are completed, so that the target parallel battery packs can be obtained, and the parallel connection mode can enable operation of the battery packs after being connected in parallel to be more stable.

Description

A battery pack parallel connection method, device and system

Technical field

The present application relates to the field of battery control technology, and in particular to a battery pack parallel connection method, device and system.

Background technique

In recent years, with the development of new energy technology, lithium batteries have become the mainstream energy storage battery. In order to increase the capacity of energy storage batteries, multiple battery packs are usually connected in parallel to obtain a better energy storage system.

In related technologies, when battery packs are connected in parallel, a random order is used to connect them in parallel. This causes the energy storage system to run unstable or even malfunction if the voltage difference between the two parallel-connected battery packs is too large.

Contents of the invention

In order to solve the problems of the prior art, embodiments of the present application provide a battery pack parallel connection method, device and system. The technical solutions are as follows:

On the one hand, a parallel connection method of battery packs is provided, and the method includes:

Get the average voltage values corresponding to multiple battery packs;

Based on the average voltage value, a target battery group is determined from the plurality of battery groups; the difference between the voltage value of the target battery group and the average voltage value is less than the difference between the average voltage value and the voltage values of the remaining battery groups; the remaining The battery pack is any battery pack except the target battery pack;

Based on the voltage value of the target battery pack, determine the target remaining battery pack from the remaining battery packs; the difference between the voltage value of the target remaining battery pack and the voltage value of the target battery pack is less than or equal to the first preset threshold;

Determine the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack;

When the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack is less than or equal to the second preset threshold, the target battery pack and the target remaining battery pack are processed in parallel to obtain the target parallel battery pack. ;The second preset threshold is greater than or equal to the first preset threshold.

In an exemplary embodiment, based on the average voltage value, a target battery group is determined from multiple battery groups, including:

Get the voltage value of each battery pack in multiple battery packs;

For each battery group in the plurality of battery groups, determine the difference between the voltage value of the battery group and the average voltage value to obtain the first voltage difference value of the battery group;

determining a first voltage difference set based on a first voltage difference value of each of the plurality of battery groups;

The battery group corresponding to the smallest first voltage difference value in the first voltage difference value set is determined as the target battery group.

In an exemplary embodiment, when there are at least two remaining battery groups, determining the target remaining battery group from the remaining battery groups based on the voltage value of the target battery group includes:

For each remaining battery group, determine the difference between the voltage value of the remaining battery group and the voltage value of the target battery group, and obtain the second voltage difference value of the remaining battery group;

determining a second set of voltage differences based on a second voltage difference for each of the at least two remaining battery packs;

Determine the minimum second voltage difference value in the second voltage difference value set as the first preset threshold;

Based on the first preset threshold, a target remaining battery group is determined from at least two remaining battery groups.

In an exemplary embodiment, after determining the target battery group from the plurality of battery groups based on the average voltage value, the method further includes:

Get the preset voltage difference;

Perform voltage equalization processing on multiple battery packs based on the preset voltage difference to obtain a voltage data set; the voltage data set includes the updated voltage value of each battery pack after voltage equalization;

The voltage value of each battery group is adjusted based on the updated voltage value of each battery group in the voltage data set, and the adjusted voltage value of each battery group is used as the voltage value of each battery group.

In an exemplary embodiment, after determining the target remaining battery pack from at least two remaining battery packs based on the first preset threshold, the method further includes:

Determine the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack as the target voltage difference;

Perform voltage equalization processing on multiple battery groups based on the target voltage difference to obtain a voltage data set; the voltage data set includes the updated voltage value of each battery group after voltage equalization;

Adjust the voltage value of each battery group based on the updated voltage value of each battery group in the voltage data set, and use the adjusted voltage value of each battery group as the voltage value of each battery group;

A quasi-target battery group is determined from multiple battery groups based on the target battery group and the voltage data set; the quasi-target battery group is the battery corresponding to the voltage value with the smallest difference between the voltage value of the target battery group and the voltage value of the target battery group among at least two remaining battery groups. Group;

The quasi-target battery pack is determined as the target remaining battery pack.

In an exemplary embodiment, the target battery pack and the target remaining battery pack are processed in parallel to obtain the target parallel battery pack, including:

Perform parallel processing on the target battery pack and the target remaining battery pack to obtain a parallel battery pack;

Use the parallel battery pack as the target battery pack, and determine the target remaining battery pack from the remaining battery packs based on the voltage value of the target battery pack; the difference between the voltage value of the target remaining battery pack and the voltage value of the target battery pack Less than or equal to the first preset threshold; the remaining battery pack is any battery pack except the target battery pack; the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack is determined as the target voltage difference , voltage equalization processing is performed on multiple battery groups based on the target voltage difference to obtain a voltage data set; the voltage data set includes the updated voltage value of each battery group after voltage equalization; each battery group is adjusted based on the updated voltage value of each battery group in the voltage data set. The voltage value of the battery group, and use the adjusted voltage value of each battery group as the voltage value of each battery group; determine the quasi-target battery group from multiple battery groups based on the target battery group and voltage data set; quasi-target battery group It is the battery group corresponding to the voltage value with the smallest difference between the voltage value of the target battery group and the voltage value of the target battery group among at least two remaining battery groups; determine the quasi-target battery group as the target remaining battery group; determine the voltage value of the target battery group and the target remaining battery The difference between the voltage values of the groups; when the difference between the voltage value of the target battery group and the voltage value of the target remaining battery group is less than or equal to the second preset threshold, the target battery group and the target remaining battery are Groups are processed in parallel to obtain parallel battery groups until there are no battery groups that have not been judged for parallel connection, and the corresponding parallel battery group when the execution is completed is determined as the target parallel battery.

In an exemplary embodiment, when there are at least two remaining battery groups, the target battery group and the target remaining battery group are processed in parallel to obtain the target parallel battery group, including:

Perform parallel processing on the target battery pack and the target remaining battery pack to obtain a parallel battery pack;

Use the parallel battery pack as the target battery pack, and determine the target remaining battery pack from the remaining battery packs based on the voltage value of the target battery pack; the difference between the voltage value of the target remaining battery pack and the voltage value of the target battery pack Less than or equal to the first preset threshold; determining the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack; the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack When the second preset threshold is less than or equal to the second preset threshold, parallel processing is performed on the target battery pack and the target remaining battery pack to obtain the target parallel battery pack; the second preset threshold is greater than or equal to the first preset threshold until the step does not exist. For battery packs that have not been judged for parallel connection, the corresponding parallel-connected battery pack when the execution is completed is determined as the target parallel-connected battery.

In an exemplary embodiment, determining the battery group corresponding to the smallest first voltage difference in the first voltage difference set as the target battery group includes:

Determine the smallest first voltage difference in the set of first voltage differences;

Determine a target battery pack set from the plurality of battery packs based on the minimum first voltage difference; the first voltage difference of the battery packs in the target battery pack set is equal to the minimum first voltage difference;

When the number of battery packs contained in the target battery pack set is greater than or equal to two, any battery pack is selected from the target battery pack set as the target battery pack.

On the other hand, a battery pack parallel connection device is provided, which device includes:

Acquisition module, used to obtain the average voltage values corresponding to multiple battery packs;

The first determination module is used to determine the target battery group from multiple battery groups based on the average voltage value; the difference between the voltage value of the target battery group and the average voltage value is less than the average voltage value and the voltage value of the remaining battery groups. The difference between them; the remaining battery pack is any battery pack except the target battery pack;

The second determination module is configured to determine the target remaining battery pack from the remaining battery packs based on the voltage value of the target battery pack; the voltage value of the target remaining battery pack and the voltage value of the target battery pack are less than or equal to the first preset threshold;

a difference determination module, used to determine the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack;

a parallel connection module, configured to perform parallel processing on the target battery pack and the target remaining battery pack when the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack is less than or equal to the second preset threshold, The target parallel battery pack is obtained; the second preset threshold is greater than or equal to the first preset threshold.

On the other hand, a battery pack parallel connection system is provided, which includes a connected control unit and multiple battery packs connected in parallel; the above battery pack parallel connection device is deployed in the control unit.

The embodiment of the present application first calculates the average voltage value of multiple battery packs to be connected in parallel, and then selects the battery pack with the closest average voltage value from the multiple battery packs as the target battery pack and the battery pack with the closest voltage value to the target battery pack. target remaining battery pack to connect the two in parallel. The smaller the voltage difference between two battery packs connected in parallel, the more stable the performance of the parallel-connected battery pack.

The embodiment of the present application first obtains the average voltage value corresponding to multiple battery packs to be connected in parallel, and then selects the battery pack closest to the average voltage value from the multiple battery packs as the target battery pack and the battery pack with the closest voltage value to the target battery pack. The remaining battery packs that are close to the target are connected in parallel, and then the parallel-connected battery pack is used as the target battery pack, and the remaining battery packs that are not judged in parallel are repeatedly determined to determine the remaining battery packs whose voltage value is close to the target battery pack. , and process the two in parallel until the parallel judgment and corresponding parallel connection of all battery packs are completed, so that the target parallel battery pack can be obtained. This parallel connection method can make the operation of the parallel battery pack more stable.

Description of the drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without exerting creative efforts.

Figure 1 is a schematic structural diagram of a battery pack parallel system provided by an embodiment of the present application;

Figure 2 is a schematic flow chart of a battery pack parallel connection method provided by an embodiment of the present application;

Figure 3 is a schematic flowchart of another battery pack parallel connection method provided by an embodiment of the present application;

Figure 4 is a schematic parallel connection diagram of the first battery pack provided by the embodiment of the present application;

Figure 5 is a schematic parallel connection diagram of the second battery pack provided by the embodiment of the present application;

Figure 6 is a schematic parallel connection diagram of the third battery pack provided by the embodiment of the present application;

FIG. 7 is a schematic structural diagram of a battery pack parallel device provided by an embodiment of the present application.

Detailed ways

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 only some of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of this application.

It should be noted that the terms "first", "second", etc. in the description and claims of this application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It is to be understood that the data so used are interchangeable under appropriate circumstances so that the embodiments of the application described herein can be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "include" and "having" and any variations thereof are intended to cover non-exclusive inclusions, e.g., a process, method, system, product or server that encompasses a series of steps or units and need not be limited to those explicitly listed. Those steps or elements may instead include other steps or elements not expressly listed or inherent to the process, method, product or apparatus.

Please refer to FIG. 1 , which is a schematic structural diagram of a battery pack parallel system provided by an embodiment of the present application. The provided battery parallel system (which may also be called an energy storage system) includes a connected control unit and multiple battery packs; a battery pack parallel device is deployed in the control unit. The battery pack parallel connection device is used to obtain the average voltage value corresponding to multiple battery packs to be connected in parallel, and then select the battery pack closest to the average voltage value from the multiple battery packs as the target battery pack and the voltage value that is the same as the target battery pack The closest remaining battery pack to the target is connected in parallel, and then the parallel connected battery pack is used as the target battery pack, and the remaining battery packs whose voltage value is close to the target battery pack are determined from the remaining battery packs judged not to be in parallel. groups, and the two are processed in parallel until the parallel judgment and corresponding parallel connection of all battery groups are completed, so that the target parallel battery group can be obtained.

Optionally, the control unit can be connected to multiple battery packs respectively, and a control switch is provided on the connection line between each battery pack and the control unit, so that multiple selected battery packs can be powered on in parallel. To meet the required battery capacity requirements and increase the load capacity of the system.

Optionally, a voltage detection device can be provided on each battery group to obtain the voltage value corresponding to each battery group.

Optionally, each battery pack includes multiple batteries connected in series or in parallel.

Optionally, the control unit can be set on a terminal or server.

Please refer to FIG. 2 , which is a schematic flowchart of a battery pack parallel connection method provided by an embodiment of the present application. This method can be applied to the battery pack parallel connection device in FIG. 1 . It should be noted that this specification provides method operation steps as described in the examples or flow charts, but more or less operation steps may be included based on conventional or non-creative efforts. The sequence of steps listed in the embodiment is only one way of executing the sequence of many steps, and does not represent the only execution sequence. When the actual system or product is executed, it may be executed sequentially or in parallel (for example, in a parallel processor or multi-threaded processing environment) according to the methods shown in the embodiments or drawings. Specifically as shown in Figure 2, the method may include:

S201: Obtain the average voltage values corresponding to multiple battery packs.

In this embodiment, step S201 can be specifically described as: obtaining the voltage value of each battery group in the plurality of battery groups, and determining the corresponding voltage value of the multiple battery groups based on the voltage value of each battery group in the plurality of battery groups. the average voltage value. Optionally, the average voltage values corresponding to the multiple battery groups can be obtained by calculating the arithmetic average of the voltage values of the multiple battery groups. For example, the battery pack set includes N battery packs as shown in Figure 1, namely battery pack 1, battery pack 2,..., battery pack N, where N is a positive number greater than 2, and the voltage value of battery pack 1 is V1 , the voltage value of battery pack 2 is V2, and so on, the voltage value of battery pack N is VN, then the average voltage value corresponding to multiple battery packs =(V1+V2……+VN)/N.

In this embodiment, a voltage detection device is used to collect the voltage value of each battery pack in real time, and the corresponding voltage values of multiple battery packs are stored for subsequent steps to obtain.

S203: Determine the target battery group from multiple battery groups based on the average voltage value; the difference between the voltage value of the target battery group and the average voltage value is less than the difference between the average voltage value and the voltage values of the remaining battery groups. ;The remaining battery packs are any battery packs except the target battery pack.

In an exemplary embodiment, please refer to Figure 3. The specific implementation of step S203 may include:

S2031: Obtain the voltage value of each battery group in multiple battery groups.

In this embodiment, since the voltage value of each battery pack has been collected and stored in step S201, step S2031 can be skipped and directly transferred to step S2033.

In this embodiment, the voltage value data set may be constructed based on the corresponding voltage values of multiple battery groups. The voltage value data set includes each battery group identifier and the corresponding voltage value.

S2033: For each battery group in the plurality of battery groups, determine the difference between the voltage value of the battery group and the average voltage value, and obtain the first voltage difference value of the battery group.

In this embodiment, the first voltage value difference here is an absolute value of the difference, so there is no need to specifically determine the subtrahend and the minuend during the calculation process, which improves calculation efficiency. Optionally, the first voltage difference can also be a positive number.

S2035: Determine a first voltage difference set based on the first voltage difference value of each battery group in the plurality of battery groups.

In an exemplary embodiment, the first voltage difference set includes an identification of each battery group and a corresponding first voltage difference.

S2037: Determine the battery group corresponding to the smallest first voltage difference in the first voltage difference set as the target battery group. In an exemplary embodiment, the specific implementation of step S2037 may include: determining the minimum first voltage difference in the first voltage difference set; determining the target from the plurality of battery packs based on the minimum first voltage difference. Battery pack set; the first voltage difference value of the battery packs in the target battery pack set is equal to the minimum first voltage difference value; when the number of battery packs contained in the target battery pack set is greater than or equal to two, from the target battery pack set Select any battery pack as the target battery pack.

In another exemplary embodiment, the specific implementation of step S203 may also be: store the average voltage value in a voltage value data set, and compare the voltages of each battery pack in the voltage value data set in order from small to large voltage values. The values are sorted to determine the serial number closest to the serial number of the average voltage value, and the battery pack corresponding to the serial number closest to the serial number of the average voltage value is determined as the target battery pack. If there are two serial numbers that are closest to the average voltage value, the difference between the voltage values corresponding to the two serial numbers and the average voltage value can be calculated to determine the battery group corresponding to the smallest difference as the target battery group.

Subsequently, the target remaining battery pack can be determined based on the voltage value of the target battery pack, and the target battery pack and the target remaining battery pack can be connected in parallel to obtain a parallel battery pack. The parallel battery pack can be used as the target battery pack, and the target battery pack can be executed based on the target battery pack. The voltage value is used to determine the target remaining battery pack, and the target battery pack is connected in parallel with the target remaining battery pack to obtain the steps of parallel battery packs, until all battery packs complete the parallel connection judgment, and the final parallel battery pack is determined as the target Batteries connected in parallel. Specifically, the above process may include the following three implementation modes.

The first implementation can be described as follows:

S205: Determine the target remaining battery pack from the remaining battery packs based on the voltage value of the target battery pack; the difference between the voltage value of the target remaining battery pack and the voltage value of the target battery pack is less than or equal to the first preset threshold.

In an exemplary embodiment, when there are at least two remaining battery groups, the specific implementation of step S205 may include: for each remaining battery group, determine the voltage value of the remaining battery group and the voltage value of the target battery group. The difference between them is used to obtain the second voltage difference of the remaining battery groups; the second voltage difference set is determined based on the second voltage difference of each remaining battery group in the at least two remaining battery groups; the second voltage difference is concentrated The minimum second voltage difference is determined as a first preset threshold; based on the first preset threshold, a target remaining battery group is determined from at least two remaining battery groups.

S207: Determine the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack.

S209: When the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack is less than or equal to the second preset threshold, perform parallel processing on the target battery pack and the target remaining battery pack to obtain the target parallel connection. Battery pack; the second preset threshold is greater than or equal to the first preset threshold.

In an exemplary embodiment, when there are at least two remaining battery packs, in step S209, the target battery pack and the target remaining battery pack are processed in parallel to obtain the target parallel battery pack, including: matching the target battery pack and the target remaining battery pack. The target remaining battery pack is processed in parallel to obtain a parallel battery pack; the parallel battery pack is used as the target battery pack, and based on the voltage value of the target battery pack, the target remaining battery pack is determined from the remaining battery pack; the voltage of the target remaining battery pack The difference between the value and the voltage value of the target battery pack is less than or equal to the first preset threshold; determine the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack; when the voltage value of the target battery pack When the difference between the voltage value of the target remaining battery pack and the target remaining battery pack is less than or equal to the second preset threshold, the target battery pack and the target remaining battery pack are processed in parallel to obtain the target parallel battery pack; the second preset threshold is greater than Or a step equal to the first preset threshold, until there is no battery group that has not been judged for parallel connection, and the corresponding parallel battery group when the execution is completed is determined as the target parallel battery.

Please refer to Figure 4. After the target battery group is determined, by determining the target remaining battery group (assumed to be the remaining battery group 1) from the n remaining battery groups, the target remaining battery group is the same as the target battery group among the n remaining battery groups. For the battery group corresponding to the voltage value with the smallest difference, connect the target battery group and the remaining battery group 1 in parallel to obtain the parallel battery group 1. n is an integer greater than or equal to 2. Taking the parallel battery pack 1 as the target battery pack, determine the target remaining battery pack (assumed to be the remaining battery pack 2) from the n-1 remaining battery packs. The target remaining battery pack is the same as the target battery pack among the n-1 remaining battery packs. For the battery pack corresponding to the voltage value with the smallest difference, connect the target battery pack and the remaining battery pack 2 in parallel to obtain the parallel battery pack 2. Repeat the above to set the parallel battery pack as the target battery pack, and select the remaining battery pack from the remaining unjudged ones. Determine the target remaining battery pack in the battery pack, and connect the target battery pack and the target remaining battery pack in parallel until there is no battery pack that has not been judged for parallel connection, so that the corresponding parallel battery pack when the execution is completed is used as the target battery pack, using The above parallel connection method not only has low resource consumption, but also effectively ensures the operational reliability of the parallel battery pack.

It can be understood that step S205 can also determine the target remaining battery pack by using the above-mentioned sorting method according to the voltage value, and determine the voltage value closest to the voltage value of the target battery pack based on the above-sorted voltage value data set, and determine The target serial number is obtained from the serial number adjacent to the serial number of the target battery pack, and the battery pack corresponding to the target serial number is determined as the target battery pack. If the target serial number includes two serial numbers, the difference between the voltage values corresponding to the two serial numbers and the voltage value of the target battery pack can be calculated, and the battery pack corresponding to the smallest difference value can be determined as the target battery pack. In the subsequent process of repeatedly determining the target remaining battery packs, the above sorting method can still be used, and the two battery packs corresponding to the parallel battery packs that are constantly updated in the voltage value data set can be replaced with parallel battery packs.

The second implementation can be elaborated as follows:

After step S203, the method further includes: obtaining a preset voltage difference; performing voltage equalization processing on multiple battery groups based on the preset voltage difference to obtain a voltage data set; the voltage data set includes voltage equalization of each battery group. Update the voltage value; adjust the voltage value of each battery group based on the updated voltage value of each battery group in the voltage data set, and use the adjusted voltage value of each battery group as the voltage value of each battery group. In this embodiment, the above-mentioned preset voltage difference may be a fixed voltage difference set based on experience, or may be a difference based on the target battery pack and the voltage value of the battery pack closest to the voltage value of the target battery pack. determined by the difference between them.

Subsequently, the above steps S205-S209 are followed, that is, based on the voltage value of the target battery pack, the target remaining battery pack is determined from the remaining battery packs; the difference between the voltage value of the target remaining battery pack and the voltage value of the target battery pack is less than Or equal to the first preset threshold. Determine a difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack, and the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack is less than or equal to the second preset threshold In case of battery pack; the difference between the voltage value of the target remaining battery pack and the voltage value of the target battery pack is less than or equal to the first preset threshold; determining the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack value; when the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack is less than or equal to the second preset threshold, perform parallel processing on the target battery pack and the target remaining battery pack to obtain the target parallel connection Battery pack; the step in which the second preset threshold is greater than or equal to the first preset threshold until there is no battery pack that has not been judged for parallel connection, and the corresponding parallel battery pack when the execution is completed is determined as the target parallel battery.

Please refer to Figure 5. After determining the target battery pack, first perform voltage equalization processing on all battery packs through the preset voltage difference. For example, the low-voltage battery pack can be charged through the high-voltage battery pack, and the overall performance is that the high-voltage battery pack is discharged. , the low-voltage battery pack is charged so that the voltage difference between battery packs in a certain order is ΔV0, or the voltage difference ΔV0 is less than or equal to ΔVa. Then, by determining the target remaining battery group (assumed to be the remaining battery group 1) from the n remaining battery groups, the target remaining battery group is the battery group corresponding to the voltage value with the smallest difference from the target battery group among the n remaining battery groups. , connect the target battery pack and the remaining battery pack 1 in parallel to obtain the parallel battery pack 1, use the parallel battery pack 1 as the target battery pack, and determine the target remaining battery pack (assumed to be the remaining battery pack 2) from the n-1 remaining battery packs ), the target remaining battery pack is the battery pack corresponding to the voltage value with the smallest difference from the target battery pack among the n-1 remaining battery packs. Connect the target battery pack and the remaining battery pack 2 in parallel to obtain the parallel battery pack 2. Repeat The above-mentioned steps of using the parallel battery pack as the target battery pack, determining the target remaining battery pack from the remaining battery packs that have not yet been judged, and connecting the target battery pack and the target remaining battery pack in parallel until there are no more parallel connected battery packs that have not been judged. Battery pack, so that the corresponding parallel battery pack when the execution is completed is used as the target battery pack. Compared with the first implementation mode, the parallel connection method is used because the voltage difference control is performed on each battery pack at the beginning, thus achieving parallel protection. function to prevent the situation where parallel connection cannot be performed.

The third implementation can be elaborated as follows:

After step S205, the method further includes: determining the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack as the target voltage difference; and performing voltage balancing on the multiple battery packs based on the target voltage difference. Process to obtain a voltage data set; the voltage data set includes the updated voltage value of each battery group after voltage equalization; the voltage value of each battery group is adjusted based on the updated voltage value of each battery group in the voltage data set, and the adjusted voltage value of each battery group is The voltage value is used as the voltage value of each battery group; the quasi-target battery group is determined from multiple battery groups based on the target battery group and the voltage data set; the quasi-target battery group is the voltage of at least two remaining battery groups that is consistent with the target battery group The battery group corresponding to the voltage value with the smallest difference in value; determine the quasi-target battery group as the target remaining battery group.

Subsequently, the above-mentioned step S207 is continued, and then when the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack is less than or equal to the second preset threshold, the target battery pack and the target remaining battery pack are processed. Process in parallel to obtain a parallel battery pack; use the parallel battery pack as the target battery pack, perform the above step S205, and determine the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack as the target voltage difference , voltage equalization processing is performed on multiple battery groups based on the target voltage difference to obtain a voltage data set; the voltage data set includes the updated voltage value of each battery group after voltage equalization; each battery group is adjusted based on the updated voltage value of each battery group in the voltage data set. The voltage value of the battery group, and use the adjusted voltage value of each battery group as the voltage value of each battery group; determine the quasi-target battery group from multiple battery groups based on the target battery group and voltage data set; quasi-target battery group It is the battery group corresponding to the voltage value with the smallest difference between the voltage value of the target battery group and the voltage value of the target battery group among at least two remaining battery groups; determine the quasi-target battery group as the target remaining battery group; determine the voltage value of the target battery group and the target remaining battery The difference between the voltage values of the groups; when the difference between the voltage value of the target battery group and the voltage value of the target remaining battery group is less than or equal to the second preset threshold, the target battery group and the target remaining battery are Groups are processed in parallel to obtain parallel battery groups until there are no battery groups that have not been judged for parallel connection, and the corresponding parallel battery group when the execution is completed is determined as the target parallel battery.

Please refer to Figure 6. After determining the target battery pack, first perform voltage equalization processing on all battery packs through the preset voltage difference. For example, the low-voltage battery pack can be charged through the high-voltage battery pack, and the overall performance is that the high-voltage battery pack is discharged. , the low-voltage battery pack is charged so that the voltage difference between battery packs in a certain order is ΔV0, or the voltage difference ΔV0 is less than or equal to ΔVa. Then, by determining the target remaining battery group (assumed to be the remaining battery group 1) from the n remaining battery groups, the target remaining battery group is the battery group corresponding to the voltage value with the smallest difference from the target battery group among the n remaining battery groups. , connect the target battery pack and the remaining battery pack 1 in parallel to obtain the parallel battery pack 1, use the parallel battery pack 1 as the target battery pack, and determine the target remaining battery pack (assumed to be the remaining battery pack 2) from the n-1 remaining battery packs ), the target remaining battery pack is the battery pack corresponding to the voltage value with the smallest difference from the target battery pack among the n-1 remaining battery packs, and at this time, the target battery pack (i.e., parallel battery pack 1) and the target remaining battery pack ( That is, the voltage difference between the remaining battery groups 2) is ΔV1. It is also necessary to perform voltage balancing processing on the n-1 remaining battery groups based on ΔV1, so that the voltages of adjacent battery groups tend to be consistent, and the target battery group Connect in parallel with the remaining battery pack 2 to obtain the parallel battery pack 2, repeat the above to set the parallel battery pack as the target battery pack, and determine the target remaining battery pack from the remaining battery packs that have not been judged, based on the voltage value of the target battery pack and the voltage value of the target remaining battery, to perform voltage equalization processing on all remaining battery groups, and connect the target battery group and the target remaining battery group in parallel until there is no battery group that has not been judged for parallel connection, so that The corresponding parallel battery pack when the execution is completed is used as the target battery pack. Compared with the first implementation method, the voltage difference of each battery pack is controlled at the beginning, which plays a parallel protection role, and every After a parallel connection, the voltage difference is controlled, which can further improve the stability of the parallel voltage group.

Corresponding to the battery pack parallel connection methods provided by the above embodiments, the embodiment of the present application also provides a battery pack parallel connection device, because the battery pack parallel connection device provided by the embodiment of the present application is connected in parallel with the battery packs provided by the above several embodiments. The method corresponds to the method, so the aforementioned implementation of the battery pack parallel connection method is also applicable to the battery pack parallel connection device provided in this embodiment, and will not be described in detail in this embodiment.

Please refer to Figure 7, which is a schematic structural diagram of a battery pack parallel connection device provided by an embodiment of the present application. The device has the function of implementing the battery pack parallel connection method in the above method embodiment. The function can be implemented by hardware, or A corresponding software implementation can be performed by hardware. As shown in Figure 7, the battery pack parallel device 700 may include:

Obtaining module 701 is used to obtain the average voltage values corresponding to multiple battery groups;

The first determination module 703 is used to determine a target battery group from multiple battery groups based on the average voltage value; the difference between the voltage value of the target battery group and the average voltage value is less than the average voltage value and the voltage of the remaining battery groups. The difference between the values; the remaining battery pack is any battery pack except the target battery pack;

The second determination module 705 is used to determine the target remaining battery pack from the remaining battery packs based on the voltage value of the target battery pack; the voltage value of the target remaining battery pack and the voltage value of the target battery pack are less than or equal to the first preset threshold. ;

The difference determination module 707 is used to determine the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack;

Parallel connection module 709, configured to perform parallel processing on the target battery pack and the target remaining battery pack when the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack is less than or equal to the second preset threshold. , the target parallel battery pack is obtained; the second preset threshold is greater than or equal to the first preset threshold.

In an exemplary embodiment, a first determination module is used to obtain the voltage value of each battery group in the plurality of battery groups;

For each battery group in the plurality of battery groups, determine the difference between the voltage value of the battery group and the average voltage value to obtain the first voltage difference value of the battery group;

determining a first voltage difference set based on a first voltage difference value of each of the plurality of battery groups;

The battery group corresponding to the smallest first voltage difference value in the first voltage difference value set is determined as the target battery group.

In an exemplary embodiment, when there are at least two remaining battery groups, the second determination module is configured to determine, for each remaining battery group, the difference between the voltage value of the remaining battery group and the voltage value of the target battery group. The difference between them is to obtain the second voltage difference of the remaining battery pack;

determining a second set of voltage differences based on a second voltage difference for each of the at least two remaining battery packs;

Determine the minimum second voltage difference value in the second voltage difference value set as the first preset threshold;

Based on the first preset threshold, a target remaining battery group is determined from at least two remaining battery groups.

In an exemplary embodiment, the device further includes:

Acquisition module, used to obtain the preset voltage difference;

The first equalization module is used to perform voltage equalization processing on multiple battery groups based on preset voltage differences to obtain a voltage data set; the voltage data set includes updated voltage values of each battery group after voltage equalization;

The first adjustment module is used to adjust the voltage value of each battery group based on the updated voltage value of each battery group in the voltage data set, and use the adjusted voltage value of each battery group as the voltage value of each battery group.

In an exemplary embodiment, the device further includes:

a third determination module, configured to determine the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack as the target voltage difference;

The second equalization module is used to perform voltage equalization processing on multiple battery groups based on the target voltage difference to obtain a voltage data set; the voltage data set includes the updated voltage value of each battery group after voltage equalization;

The second adjustment module is used to adjust the voltage value of each battery group based on the updated voltage value of each battery group in the voltage data set, and use the adjusted voltage value of each battery group as the voltage value of each battery group;

The fourth determination module is used to determine the quasi-target battery group from multiple battery groups based on the target battery group and the voltage data set; the quasi-target battery group is the difference between the voltage values of at least two remaining battery groups and the target battery group. The battery pack corresponding to the minimum voltage value;

The fifth determination module is used to determine the quasi-target battery pack as the target remaining battery pack.

In an exemplary embodiment, the parallel connection module is used to perform parallel processing on the target battery pack and the target remaining battery pack to obtain a parallel battery pack;

Use the parallel battery pack as the target battery pack, and determine the target remaining battery pack from the remaining battery packs based on the voltage value of the target battery pack; the difference between the voltage value of the target remaining battery pack and the voltage value of the target battery pack Less than or equal to the first preset threshold; the remaining battery pack is any battery pack except the target battery pack; the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack is determined as the target voltage difference , voltage equalization processing is performed on multiple battery groups based on the target voltage difference to obtain a voltage data set; the voltage data set includes the updated voltage value of each battery group after voltage equalization; each battery group is adjusted based on the updated voltage value of each battery group in the voltage data set. The voltage value of the battery group, and use the adjusted voltage value of each battery group as the voltage value of each battery group; determine the quasi-target battery group from multiple battery groups based on the target battery group and voltage data set; quasi-target battery group It is the battery group corresponding to the voltage value with the smallest difference between the voltage value of the target battery group and the voltage value of the target battery group among at least two remaining battery groups; determine the quasi-target battery group as the target remaining battery group; determine the voltage value of the target battery group and the target remaining battery The difference between the voltage values of the groups; when the difference between the voltage value of the target battery group and the voltage value of the target remaining battery group is less than or equal to the second preset threshold, the target battery group and the target remaining battery are Groups are processed in parallel to obtain parallel battery groups until there are no battery groups that have not been judged for parallel connection, and the corresponding parallel battery group when the execution is completed is determined as the target parallel battery.

In an exemplary embodiment, when there are at least two remaining battery groups, the parallel module is configured to perform parallel processing on the target battery group and the target remaining battery group to obtain a parallel battery group;

Use the parallel battery pack as the target battery pack, and determine the target remaining battery pack from the remaining battery packs based on the voltage value of the target battery pack; the difference between the voltage value of the target remaining battery pack and the voltage value of the target battery pack Less than or equal to the first preset threshold; determining the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack; the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack When the second preset threshold is less than or equal to the second preset threshold, parallel processing is performed on the target battery pack and the target remaining battery pack to obtain the target parallel battery pack; the second preset threshold is greater than or equal to the first preset threshold until the step does not exist. For battery packs that have not been judged for parallel connection, the corresponding parallel-connected battery pack when the execution is completed is determined as the target parallel-connected battery.

In an exemplary embodiment, the first determination module is configured to determine the smallest first voltage difference in the first voltage difference set;

Determine a target battery pack set from the plurality of battery packs based on the minimum first voltage difference; the first voltage difference of the battery packs in the target battery pack set is equal to the minimum first voltage difference;

When the number of battery packs contained in the target battery pack set is greater than or equal to two, any battery pack is selected from the target battery pack set as the target battery pack.

It should be noted that when implementing the functions of the device provided by the above embodiments, only the division of the above functional modules is used as an example. In practical applications, the above functions can be allocated to different functional modules according to needs, that is, The internal structure of the device is divided into different functional modules to complete all or part of the functions described above. In addition, the device and method embodiments provided in the above embodiments belong to the same concept, and the specific implementation process can be found in the method embodiments, which will not be described again here.

Each embodiment in this specification is described in a progressive manner. The same and similar parts between the various embodiments can be referred to each other. Each embodiment focuses on its differences from other embodiments. In particular, for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple. For relevant details, please refer to the partial description of the method embodiment.

The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the protection of the present application. within the range.

Claims (9)

1. A battery pack parallel connection method, characterized in that the method includes: Get the average voltage values corresponding to multiple battery packs; Based on the average voltage value, a target battery pack is determined from a plurality of the battery packs; the difference between the voltage value of the target battery pack and the average voltage value is less than the average voltage value and the remaining battery packs. The difference between the voltage values; the remaining battery pack is any of the battery packs except the target battery pack; Based on the voltage value of the target battery pack, a target remaining battery pack is determined from the remaining battery pack; the difference between the voltage value of the target remaining battery pack and the voltage value of the target battery pack is less than or equal to first preset threshold; Determine a difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack; In the case where the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack is less than or equal to the second preset threshold, perform an operation on the target battery pack and the target remaining battery pack. Process in parallel to obtain the target parallel battery pack; the second preset threshold is greater than or equal to the first preset threshold; After determining a target battery pack from a plurality of battery packs based on the average voltage value, the method further includes: Get the preset voltage difference; Perform voltage equalization processing on a plurality of battery packs based on the preset voltage difference to obtain a voltage data set; the voltage data set includes updated voltage values of each battery pack after voltage equalization; The voltage value of each battery group is adjusted based on the updated voltage value of each battery group in the voltage data set, and the adjusted voltage value of each battery group is used as the voltage value of each battery group. 2. The method of claim 1, wherein determining a target battery pack from a plurality of battery packs based on the average voltage value includes: Obtain the voltage value of each battery group in the plurality of battery groups; For each battery group in the plurality of battery groups, determine a difference between the voltage value of the battery group and the average voltage value to obtain a first voltage difference value of the battery group; determining a first voltage difference set based on a first voltage difference value of each of the plurality of battery packs; The battery group corresponding to the smallest first voltage difference value in the first voltage difference value set is determined as the target battery group. 3. The method according to claim 1, characterized in that, in the case where there are at least two remaining battery groups, the voltage value of the target battery group is determined from the remaining battery groups. Target remaining battery packs include: For each of the remaining battery groups, determine the difference between the voltage value of the remaining battery group and the voltage value of the target battery group, and obtain a second voltage difference value of the remaining battery group; determining a second set of voltage differences based on the second voltage differences of each of the remaining battery groups in at least two of the remaining battery groups; Determine the minimum second voltage difference value in the second voltage difference value set as the first preset threshold; Based on the first preset threshold, the target remaining battery pack is determined from at least two of the remaining battery packs. 4. The method according to claim 3, wherein after determining the target remaining battery pack from at least two remaining battery packs based on the first preset threshold, the method further include: Determine the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack as the target voltage difference; Perform voltage equalization processing on a plurality of battery packs based on the target voltage difference to obtain a voltage data set; the voltage data set includes updated voltage values of each battery pack after voltage equalization; Adjust the voltage value of each battery group based on the updated voltage value of each battery group in the voltage data set, and use the adjusted voltage value of each battery group as the voltage value of each battery group; A quasi-target battery pack is determined from a plurality of battery packs based on the target battery pack and the voltage data set; the quasi-target battery pack is the battery pack that is the same as the target battery pack among at least two remaining battery packs. The battery pack corresponding to the voltage value with the smallest difference in voltage value; The quasi-target battery pack is determined as the target remaining battery pack. 5. The method according to claim 4, wherein the parallel processing of the target battery pack and the target remaining battery pack to obtain the target parallel battery pack includes: Perform parallel processing on the target battery pack and the target remaining battery pack to obtain a parallel battery pack; The parallel battery pack is used as the target battery pack, and based on the voltage value of the target battery pack, the target remaining battery pack is determined from the remaining battery packs; the voltage value of the target remaining battery pack is consistent with the target battery pack. The difference between the voltage values of the target battery packs is less than or equal to the first preset threshold; the remaining battery packs are any of the battery packs except the target battery pack; the voltage of the target battery pack is The difference between the target voltage value and the voltage value of the target remaining battery pack is determined as the target voltage difference. Based on the target voltage difference, voltage equalization processing is performed on a plurality of the battery packs to obtain a voltage data set; the voltage data set Including the updated voltage value of each battery group after voltage balancing; adjusting the voltage value of each battery group based on the updated voltage value of each battery group in the voltage data set, and using the adjusted voltage value of each battery group as the voltage value; determining a quasi-target battery pack from a plurality of the battery packs based on the target battery pack and the voltage data set; the quasi-target battery pack is at least two of the remaining battery packs that are the same as the target. The battery pack corresponding to the voltage value with the smallest difference in voltage values of the battery pack; determine the quasi-target battery pack as the target remaining battery pack; determine the voltage value of the target battery pack and the target remaining battery pack The difference between voltage values; when the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack is less than or equal to the second preset threshold, the target battery pack is Perform parallel processing with the target remaining battery packs to obtain parallel battery packs until there are no battery packs that have not been judged for parallel connection, and determine the corresponding parallel battery pack when the execution is completed as the target parallel battery. 6. The method according to claim 1, characterized in that, when there are at least two remaining battery packs, the target battery pack and the target remaining battery pack are processed in parallel to obtain the target battery pack. Parallel battery pack, including: Perform parallel processing on the target battery pack and the target remaining battery pack to obtain a parallel battery pack; The parallel battery pack is used as the target battery pack, and based on the voltage value of the target battery pack, the target remaining battery pack is determined from the remaining battery packs; the voltage value of the target remaining battery pack is consistent with the target battery pack. The difference between the voltage values of the target battery pack is less than or equal to the first preset threshold; determine the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack; in the target When the difference between the voltage value of the battery pack and the voltage value of the target remaining battery pack is less than or equal to the second preset threshold, the target battery pack and the target remaining battery pack are processed in parallel to obtain Target parallel battery pack; the step of the second preset threshold being greater than or equal to the first preset threshold, until there is no battery pack that has not been judged for parallel connection, and determining the corresponding parallel battery pack when the execution is completed as the Target parallel batteries. 7. The method of claim 2, wherein determining the battery group corresponding to the smallest first voltage difference in the first voltage difference set as the target battery group includes: Determine the minimum first voltage difference in the first voltage difference set; Based on the minimum first voltage difference, a target battery pack set is determined from the plurality of battery packs; the first voltage difference of the battery packs in the target battery pack set is equal to the minimum first voltage difference; When the number of battery packs included in the target battery pack set is greater than or equal to two, one battery pack is randomly selected from the target battery pack set as the target battery pack. 8. A battery pack parallel connection device, characterized in that it is used to implement the battery pack parallel connection method according to any one of claims 1 to 7, and the device includes: The acquisition module is used to obtain the average voltage values corresponding to multiple battery packs and obtain the preset voltage difference; A first determination module, configured to determine a target battery pack from a plurality of battery packs based on the average voltage value; the difference between the voltage value of the target battery pack and the average voltage value is less than the The difference between the average voltage value and the voltage value of the remaining battery pack; the remaining battery pack is any battery pack except the target battery pack; The second determination module is configured to determine a target remaining battery pack from the remaining battery pack based on the voltage value of the target battery pack; the voltage value of the target remaining battery pack and the voltage value of the target battery pack are less than Or equal to the first preset threshold; a difference determination module, configured to determine the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack; A parallel connection module, configured to configure the target battery pack and the target battery pack when the difference between the voltage value of the target battery pack and the voltage value of the target remaining battery pack is less than or equal to a second preset threshold. The target remaining battery packs are processed in parallel to obtain the target parallel battery packs; the second preset threshold is greater than or equal to the first preset threshold; A first equalization module, configured to perform voltage equalization processing on a plurality of battery packs based on the preset voltage difference to obtain a voltage data set; the voltage data set includes the updated voltage of each battery pack after voltage equalization. value; The first adjustment module is configured to adjust the voltage value of each battery group based on the updated voltage value of each battery group in the voltage data set, and use the adjusted voltage value of each battery group as the voltage value of each battery group. 9. A battery pack parallel system, characterized in that it includes a control unit and multiple battery packs connected in parallel; The battery pack parallel device as claimed in claim 8 is deployed in the control unit.