A power battery pack control method and a power battery pack

Abstract

The present invention provides a power battery pack control method and a power battery pack, the power battery pack control method comprises the following steps: obtaining the power supply capacity of a first battery pack and a second battery pack connected in parallel, wherein the power supply capacity includes the remaining capacity and the loaded voltage; determining the main discharge pack and the auxiliary discharge pack in the first battery pack and the second battery pack according to the power supply capacity, wherein the main discharge pack is suitable for supplying power to a load alone, or supplying power to the load together with the auxiliary discharge pack; when the auxiliary discharge pack supplies power to the load together, controlling the discharge current of the auxiliary discharge pack to increase from a low discharge current to a high discharge current. The beneficial effects of the present invention: the discharge efficiency of the battery pack can be improved.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a power battery pack control method and a power battery pack. Background Art

[0002] In the application scenarios of power battery packs, for example, when supplying power to loads such as power tools, most of the cells in the battery packs are in a high discharge rate usage environment. Since the cells in the battery pack have the strongest load capacity at and above the rated voltage platform, when the cells are discharged to a certain voltage point below the rated voltage, the cells can easily be discharged by the large load current and pulled down to the battery pack undervoltage protection state. At this time, the power tool will stop working, and a considerable portion of the electricity in the cells cannot be released, ultimately resulting in a reduction in the overall discharge efficiency of the battery pack. Summary of the invention

[0003] The present invention aims to solve the technical problem of how to improve the discharge efficiency of a battery pack.

[0004] To achieve the above object, the present invention provides a power battery pack control method, comprising the steps of:

[0005] Acquire power supply capabilities of a first battery pack and a second battery pack connected in parallel, wherein the power supply capabilities include remaining capacity and load voltage;

[0006] Determine, according to the power supply capability, a main discharge pack and an auxiliary discharge pack in the first battery pack and the second battery pack, wherein the main discharge pack is suitable for supplying power to a load alone, or supplying power to the load together with the auxiliary discharge pack;

[0007] When the auxiliary discharge pack supplies power to the load, the discharge current of the auxiliary discharge pack is controlled to increase from a low discharge current to a high discharge current.

[0008] The control method of the power battery pack in the technical solution obtains the power supply capacity of the first battery pack and the second battery pack in parallel, that is, specifically obtains the remaining capacity and the loaded voltage of the two battery packs to accurately estimate the power supply capacity of the two battery packs to the load, thereby confirming the main discharge pack and the auxiliary discharge pack in the first battery pack and the second battery pack, and then the main discharge pack can supply power to the load alone, or the main discharge pack and the auxiliary discharge pack can supply power to the load at the same time, so as to ensure a better power supply effect; due to the parallel addition of the battery pack, the capacity of the battery pack group is significantly increased, and the battery The output current capacity of the pack group is improved accordingly, the current demand of a single battery pack is reduced, the discharge rate of a corresponding single battery pack is reduced, the voltage drop rate is slowed down, the working cycle of entering the undervoltage protection point is lengthened, and the capacity utilization efficiency of the battery cell can be improved; the discharge current of the auxiliary discharge pack is controlled to increase from a low discharge current to a high discharge current to supply power to the load, so that the capacity of the battery pack can be fully released, and the discharge efficiency of the main and auxiliary discharge packs can be maximized; and the release process is more reasonable, which improves the stability of the power supply, and can better protect the equipment and increase the service life of the battery pack.

[0009] Further, the determining, according to the power supply capability, a main discharge pack and an auxiliary discharge pack in the first battery pack and the second battery pack comprises:

[0010] When it is determined that the remaining capacity of the first battery pack is greater than the sum of the remaining capacity of the second battery pack and a preset error capacity, determining the first battery pack as the main discharge pack and determining the second battery pack as the auxiliary discharge pack;

[0011] When it is determined that the remaining capacity of the first battery pack is less than the difference between the remaining capacity of the second battery pack and the preset error capacity, the second battery pack is determined to be the main discharge pack, and the first battery pack is determined to be the auxiliary discharge pack.

[0012] Further, the determining the main discharge pack and the auxiliary discharge pack in the first battery pack and the second battery pack according to the power supply capability further includes:

[0013] When the difference between the remaining capacity of the first battery pack and the remaining capacity of the second battery pack is within a first preset error range, the main discharge pack and the auxiliary discharge pack in the first battery pack and the second battery pack are determined according to the loaded voltages of the first battery pack and the second battery pack.

[0014] Further, the determining the main discharge pack and the auxiliary discharge pack in the first battery pack and the second battery pack according to the loaded voltage of the first battery pack and the second battery pack includes:

[0015] When the load voltage of the first battery pack is greater than or equal to the load voltage of the second battery pack, the first battery pack is determined to be the main discharge pack, and the second battery pack is determined to be the auxiliary discharge pack;

[0016] When the load voltage of the first battery pack is less than the load voltage of the second battery pack, the second battery pack is determined to be the main discharge pack, and the first battery pack is determined to be the auxiliary discharge pack.

[0017] Furthermore, a maximum boundary value of the first preset error range is a sum of a product of a maximum capacity of the first battery pack and a preset percentage and the preset error capacity.

[0018] Furthermore, the power battery pack control method further includes:

[0019] When the remaining capacity of the main discharge pack is greater than the sum of the remaining capacity of the auxiliary discharge pack and the preset capacity, controlling the main discharge pack to supply power to the load alone;

[0020] When the difference between the remaining capacity of the main discharge pack and the remaining capacity of the auxiliary discharge pack is within a second preset error range, controlling the main discharge pack and the auxiliary discharge pack to supply power to the load at the same time;

[0021] When the remaining capacity of the main discharge pack is less than the difference between the remaining capacity of the auxiliary discharge pack and the preset capacity, the main discharge pack and the auxiliary discharge pack are stopped from supplying power to the load, and the main discharge pack and the auxiliary discharge pack in the first battery pack and the second battery pack are determined again.

[0022] Further, the controlling the discharge current of the auxiliary discharge pack to increase from a low discharge current to a high discharge current comprises:

[0023] Controlling the discharge current to increase linearly from the low discharge current until reaching the high discharge current, or

[0024] The discharge current is controlled to increase linearly from the low discharge current to a medium discharge current, and when the duration of the medium discharge current reaches a preset time, the discharge current is linearly increased to the high discharge current.

[0025] Furthermore, the current value of the high discharge current is less than or equal to 50% of the maximum current value of the auxiliary discharge pack.

[0026] The present invention also proposes a power battery pack, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the power battery pack control method as described above is implemented.

[0027] Furthermore, the power battery pack also includes a first battery pack, a second battery pack, parallel battery electrodes, a first NMOS component and a second NMOS component, wherein the first NMOS component is arranged between the first battery pack and the parallel battery electrodes, and the second NMOS component is arranged between the second battery pack and the parallel battery electrodes.

[0028] The power battery pack in the present invention has similar technical effects to the above-mentioned power battery pack control method, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a flow chart of a power battery pack control method in an embodiment of the present invention;

[0030] Figure 2 4 is a structural block diagram of a power battery pack in an embodiment of the present invention. DETAILED DESCRIPTION

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0032] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein.

[0033] In the description of this specification, the description with reference to the terms "embodiment", "one embodiment" and "one implementation" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or implementation are included in at least one embodiment or implementation of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or implementation. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or implementations in a suitable manner.

[0034] Reference Figure 1 As shown, an embodiment of the present invention proposes a power battery pack control method, comprising the steps of:

[0035] S1. Obtaining power supply capabilities of a first battery pack and a second battery pack connected in parallel, wherein the power supply capabilities include remaining capacity and load voltage;

[0036] S2. Determine a main discharge pack and an auxiliary discharge pack in the first battery pack and the second battery pack according to the power supply capability, wherein the main discharge pack is suitable for supplying power to a load alone, or supplying power to the load together with the auxiliary discharge pack;

[0037] S3. When the auxiliary discharge pack supplies power to the load, control the discharge current of the auxiliary discharge pack to increase from a low discharge current to a high discharge current.

[0038] The power battery pack control method in the embodiment of the present invention can be specifically used to control a power battery pack having at least two battery packs, for example, Figure 2 The power battery pack of the principle shown has two parallel-connected first battery packs and second battery packs. The two battery packs can be connected to the load at the same time to supply power at the same time, or one of them can be connected to the load to supply power separately.

[0039] When the power battery pack is in use, after a certain number of cyclic discharge operations, the battery cell ages and the voltage of the battery pack cannot truly reflect the power supply capacity of the battery pack. Therefore, in this embodiment, the power supply capacity of the first battery pack and the second battery pack connected in parallel is obtained, that is, the remaining capacity (effective remaining capacity) of the two battery packs and the loaded voltage of the two battery packs are obtained, wherein the loaded voltage is the voltage under a preset fixed load. Thus, the power supply capacity of the two battery packs is confirmed by the remaining capacity and the loaded voltage, so that the power supply capacity of the two battery packs to the load can be more accurately determined, and then the main discharge pack and the auxiliary discharge pack in the first battery pack and the second battery pack are confirmed. Based on After the main and auxiliary are confirmed and set, the two battery packs can make the main discharge pack supply power to the load alone, or make the main discharge pack and the auxiliary discharge pack supply power to the load at the same time, so as to ensure a better power supply effect. It can be understood that when the main discharge pack has a better power supply capacity, it can realize independent power supply. When the power supply capacity of the main discharge pack decreases, the main discharge pack and the auxiliary discharge pack can be connected in parallel to supply power at the same time. Due to the parallel addition of the battery packs, the capacity of the battery pack group is significantly increased, the output current capacity of the battery pack group is correspondingly improved, the current demand of a single battery pack is reduced, the discharge rate of the corresponding single battery pack is reduced, the voltage drop speed is slowed down, and the working cycle of entering the undervoltage protection point is lengthened, and the capacity utilization efficiency of the battery cell can be improved.

[0040] It can be understood that since the power supply capacity of the battery pack is a changing process, better switching between separate power supply or simultaneous power supply can be achieved according to the change of power supply capacity, and the main and auxiliary identification of the first battery pack and the second battery pack can also be a dynamic and re-identified process based on the power supply capacity. That is, when the power supply capacity of the main discharge pack drops too much and is lower than that of the auxiliary discharge pack, it can be re-identified and set to reasonably supply power and maximize the utilization efficiency of the battery pack.

[0041] Among them, when the auxiliary discharge pack supplies power to the load, the discharge current of the auxiliary discharge pack is controlled to increase from a low discharge current to a high discharge current, so that the capacity of the battery pack can be fully released and the discharge efficiency of the main and auxiliary discharge packs can be improved as much as possible; and the release process is more reasonable, which improves the stability of power supply, and can better protect the equipment and increase the service life of the battery pack.

[0042] In an optional embodiment of the present invention, determining the main discharge pack and the auxiliary discharge pack in the first battery pack and the second battery pack according to the power supply capability includes:

[0043] When it is determined that the remaining capacity of the first battery pack is greater than the sum of the remaining capacity of the second battery pack and a preset error capacity, determining the first battery pack as the main discharge pack and determining the second battery pack as the auxiliary discharge pack;

[0044] When it is determined that the remaining capacity of the first battery pack is less than the difference between the remaining capacity of the second battery pack and the preset error capacity, the second battery pack is determined to be the main discharge pack, and the first battery pack is determined to be the auxiliary discharge pack.

[0045] In the present embodiment, when determining the main discharge pack and the auxiliary discharge pack in the first battery pack and the second battery pack according to the remaining capacity, the determination is made specifically through the remaining capacity of the two battery packs, and a preset error capacity is set for combined judgment. The preset error capacity is used to reflect the difference between the remaining capacities of the two battery packs, to facilitate the power supply control of the main power supply and the auxiliary power supply, and to avoid misjudgment, thereby facilitating the power supply control of the main discharge pack and the auxiliary discharge pack.

[0046] Specifically, when the difference between the remaining capacity of the battery pack with the larger remaining capacity and the remaining capacity of the other battery pack with the smaller remaining capacity is greater than the sum of the preset error capacity, the battery pack with the larger remaining capacity is determined to be the main discharge pack and the battery pack with the smaller remaining capacity is determined to be the auxiliary discharge pack. In other cases, other methods can be used to determine the main and auxiliary discharge packs, such as setting one of the two battery packs with similar power supply capabilities as the main discharge pack by default.

[0047] In an optional embodiment of the present invention, determining the main discharge pack and the auxiliary discharge pack in the first battery pack and the second battery pack according to the power supply capability further includes:

[0048] When the difference between the remaining capacity of the first battery pack and the remaining capacity of the second battery pack is within a first preset error range, the main discharge pack and the auxiliary discharge pack in the first battery pack and the second battery pack are determined according to the loaded voltages of the first battery pack and the second battery pack.

[0049] In this embodiment, specifically, when the difference between the remaining capacity of the first battery pack and the remaining capacity of the second battery pack is within the first preset error range, it means that the remaining capacity of the first battery pack and the remaining capacity of the second battery pack do not have a large difference, wherein the maximum boundary value of the first preset error range is the product of the maximum capacity of the first battery pack and the preset percentage and the sum of the preset error capacity. In this embodiment, the preset percentage can be 3%, that is, when the difference between the remaining capacity of the first battery pack and the remaining capacity ± the error capacity of the second battery pack is less than 3% of the maximum capacity, the main and auxiliary discharge packs are confirmed in combination with the load voltage, so that the main and auxiliary situations of the two battery packs can be confirmed more reasonably in combination with the remaining capacity and the load voltage.

[0050] Among them, when the loaded voltage of the first battery pack is greater than or equal to the loaded voltage of the second battery pack, the first battery pack is determined to be the main discharge pack, and the second battery pack is determined to be the auxiliary discharge pack; when the loaded voltage of the first battery pack is less than the loaded voltage of the second battery pack, the second battery pack is determined to be the main discharge pack, and the first battery pack is determined to be the auxiliary discharge pack, so that the battery pack with relatively larger loaded voltage among the two battery packs is determined to be the main discharge pack, otherwise it is the auxiliary discharge pack, so as to maximize the discharge efficiency of the two battery packs.

[0051] In an optional embodiment of the present invention, the power battery pack control method further includes:

[0052] When the remaining capacity of the main discharge pack is greater than the sum of the remaining capacity of the auxiliary discharge pack and the preset capacity, controlling the main discharge pack to supply power to the load alone;

[0053] When the difference between the remaining capacity of the main discharge pack and the remaining capacity of the auxiliary discharge pack is within a second preset error range, controlling the main discharge pack and the auxiliary discharge pack to supply power to the load at the same time;

[0054] When the remaining capacity of the main discharge pack is less than the difference between the remaining capacity of the auxiliary discharge pack and the preset capacity, the main discharge pack and the auxiliary discharge pack are stopped from supplying power to the load, and the main discharge pack and the auxiliary discharge pack in the first battery pack and the second battery pack are determined again.

[0055] In this embodiment, when the power battery pack is supplying power, the main discharge pack can first supply power to the load. During the power supply process, the remaining capacity of the main discharge pack gradually decreases. If the remaining capacity continues to be greater than the sum of the remaining capacity of the auxiliary discharge pack and the preset capacity, the main discharge pack is kept supplying power to the load alone. When the remaining capacity of the main discharge pack continues to decrease, and the difference between the remaining capacity of the main discharge pack and the auxiliary discharge pack is within a second preset error range, it indicates that the remaining capacity aberration of the main discharge pack and the auxiliary discharge pack is already small. At this time, the main discharge pack and the auxiliary discharge pack are controlled to supply power at the same time to achieve better power supply efficiency. When the remaining capacity of the main discharge pack is less than the difference between the remaining capacity of the auxiliary discharge pack and the preset capacity, it indicates that the main discharge pack cannot form the main power supply function alone. At this time, the power supply to the load is disconnected. According to the control method in the above embodiment, the main discharge pack and the auxiliary discharge pack are re-determined to achieve more reasonable power supply control, which can reasonably improve the discharge efficiency and the service life of the battery pack.

[0056] In an optional embodiment of the present invention, the controlling the discharge current of the auxiliary discharge pack to increase from a low discharge current to a high discharge current comprises:

[0057] Controlling the discharge current to increase linearly from the low discharge current until reaching the high discharge current, or

[0058] The discharge current is controlled to increase linearly from the low discharge current to a medium discharge current, and when the duration of the medium discharge current reaches a preset time, the discharge current is linearly increased to the high discharge current.

[0059] In this embodiment, when the auxiliary discharge pack is supplying power, it adopts a power supply form of gradually or step-by-step increasing the current to meet the power supply requirements, so as to achieve reasonable power supply access, so as to be able to fully release the capacity of the battery pack, improve the discharge efficiency of the main and auxiliary discharge packs, and ensure the service life of the battery pack. Specifically, when increasing the current, the discharge current of the auxiliary discharge pack can be increased in a linearly increasing form, or, when the discharge current is at a low discharge current, it can be linearly increased to reach a medium discharge current, and after the medium discharge current is maintained for a preset period of time, it is linearly increased again until the required high discharge current is reached, and the current value of the high discharge current is less than or equal to 50% of the maximum current value of the auxiliary discharge pack, so as to perform auxiliary power supply when the main discharge pack and the auxiliary discharge pack are supplying power at the same time, so as to reasonably arrange the entire discharge process, so that the capacity is fully released, and the battery pack can be protected.

[0060] Among them, the preset time can be determined according to the capacity of the current main discharge pack, such as generating the preset time according to the capacity and the current power supply situation, so that it can be reasonably combined with the discharge process of the main discharge pack to maximize the discharge efficiency and protect the two battery packs as much as possible.

[0061] A power battery pack in another embodiment of the present invention includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the power battery pack control method described above is implemented.

[0062] The power battery pack in this embodiment has a technical effect similar to that of the above-mentioned power battery pack control method, which will not be described in detail here.

[0063] Reference Figure 2 As shown, the power battery pack in the present invention also includes a first battery pack, a second battery pack, parallel battery electrodes, a first NMOS component and a second NMOS component, wherein the first NMOS component is arranged between the first battery pack and the parallel battery electrodes, and the second NMOS component is arranged between the second battery pack and the parallel battery electrodes.

[0064] In this embodiment, the parallel battery electrodes include a positive electrode of the parallel battery and a negative electrode of the parallel battery. The first NMOS component is arranged between the positive electrode of the first battery pack and the positive electrode of the parallel battery. The second NMOS component can be arranged between the positive electrode of the second battery pack and the positive electrode of the parallel battery. The first NMOS component and the second NMOS component can be connected to the first MOS driver and the second MOS driver respectively, and communicate with the main control MCU (processor). The negative electrode of the parallel battery is connected to the negative electrode of the first battery pack and the negative electrode of the second battery pack, and a resistor is arranged between them to realize the power supply control of the first battery pack and the second battery pack. Among them, the first battery pack communication port and the second battery pack communication port are connected to the main control MCU for feedback of battery pack information, such as the above-mentioned load voltage and remaining capacity information.

[0065] The first NMOS component and the second NMOS component may each include a plurality of NMOS tubes connected in series.

[0066] Although the disclosure is disclosed as above, the protection scope of the disclosure is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the disclosure, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A power battery pack control method, characterized in that: include: Acquire power supply capabilities of a first battery pack and a second battery pack connected in parallel, wherein the power supply capabilities include remaining capacity and load voltage; Determine, according to the power supply capability, a main discharge pack and an auxiliary discharge pack in the first battery pack and the second battery pack, wherein the main discharge pack is suitable for supplying power to a load alone, or supplying power to the load together with the auxiliary discharge pack; When the auxiliary discharge pack supplies power to the load, controlling the discharge current of the auxiliary discharge pack to increase from a low discharge current to a high discharge current; The determining, according to the power supply capability, a main discharge pack and an auxiliary discharge pack in the first battery pack and the second battery pack comprises: When it is determined that the remaining capacity of the first battery pack is greater than the sum of the remaining capacity of the second battery pack and a preset error capacity, determining the first battery pack as the main discharge pack and determining the second battery pack as the auxiliary discharge pack; When it is determined that the remaining capacity of the first battery pack is less than the difference between the remaining capacity of the second battery pack and the preset error capacity, determining the second battery pack as the main discharge pack and determining the first battery pack as the auxiliary discharge pack; When the difference between the remaining capacity of the first battery pack and the remaining capacity of the second battery pack is within a first preset error range, the main discharge pack and the auxiliary discharge pack in the first battery pack and the second battery pack are determined according to the loaded voltages of the first battery pack and the second battery pack.

2. The power battery pack control method according to claim 1, characterized in that: The determining, according to the loaded voltages of the first battery pack and the second battery pack, a main discharge pack and an auxiliary discharge pack in the first battery pack and the second battery pack comprises: When the load voltage of the first battery pack is greater than or equal to the load voltage of the second battery pack, the first battery pack is determined to be the main discharge pack, and the second battery pack is determined to be the auxiliary discharge pack; When the load voltage of the first battery pack is less than the load voltage of the second battery pack, the second battery pack is determined to be the main discharge pack, and the first battery pack is determined to be the auxiliary discharge pack.

3. The power battery pack control method according to claim 1, characterized in that: The maximum boundary value of the first preset error range is the sum of the product of the maximum capacity of the first battery pack and a preset percentage and the preset error capacity.

4. The power battery pack control method according to any one of claims 1 to 3, characterized in that: Also includes: When the remaining capacity of the main discharge pack is greater than the sum of the remaining capacity of the auxiliary discharge pack and the preset capacity, controlling the main discharge pack to supply power to the load alone; When the difference between the remaining capacity of the main discharge pack and the remaining capacity of the auxiliary discharge pack is within a second preset error range, controlling the main discharge pack and the auxiliary discharge pack to supply power to the load at the same time; When the remaining capacity of the main discharge pack is less than the difference between the remaining capacity of the auxiliary discharge pack and the preset capacity, the main discharge pack and the auxiliary discharge pack are stopped from supplying power to the load, and the main discharge pack and the auxiliary discharge pack in the first battery pack and the second battery pack are determined again.

5. The power battery pack control method according to any one of claims 1 to 3, characterized in that: The controlling the discharge current of the auxiliary discharge pack to increase from a low discharge current to a high discharge current comprises: The discharge current is controlled to increase linearly from the low discharge current until it reaches the high discharge current, or the discharge current is controlled to increase linearly from the low discharge current to a medium discharge current, and when the medium discharge current duration reaches a preset time, the discharge current is linearly increased to the high discharge current.

6. The power battery pack control method according to claim 5, characterized in that: The current value of the high discharge current is less than or equal to 50% of the maximum current value of the auxiliary discharge pack.

7. A power battery pack, characterized in that: It includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the power battery pack control method according to any one of claims 1 to 6 is implemented.

8. The power battery pack according to claim 7, characterized in that: It also includes a first battery pack, a second battery pack, parallel battery electrodes, a first NMOS component and a second NMOS component, wherein the first NMOS component is arranged between the first battery pack and the parallel battery electrodes, and the second NMOS component is arranged between the second battery pack and the parallel battery electrodes.

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