Multi-battery-pack electrical device
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- NANJING CHERVON IND
- Filing Date
- 2025-12-03
- Publication Date
- 2026-05-21
Smart Images
Figure CN2025139532_21052026_PF_FP_ABST
Abstract
Description
Multiple packages of electrical equipment Technical Field
[0001] This application relates to the field of power tool technology, and more specifically to a multi-pack electric device. Background Technology
[0002] Large tools such as ride-on lawnmowers require multiple battery packs to work simultaneously. Displaying battery level, low battery return trip, and overall power control are all important aspects that affect the user experience of these multi-pack tools. Therefore, it is necessary to accurately estimate the SOC / SOP of the multi-pack system.
[0003] Due to the plug-and-play nature of battery packs and the fact that some battery packs themselves do not calculate their State of Charge (SOC) and inform the multi-pack system, while the system cannot identify the aging status of each battery pack, it is crucial to accurately estimate the SOC of each battery pack and then calculate the overall SOC of the device when the aging status error of the batteries is unknown.
[0004] The maximum discharge capacity of a multi-pack system is not only affected by the discharge capacity of the battery itself, but also by the constraints and control of the hardware PCB. Therefore, it is necessary to comprehensively consider the impact of battery performance and hardware constraints in order to estimate the overall system operating cost (SOP).
[0005] This section provides background information related to this application, which is not necessarily prior art. Summary of the Invention
[0006] One object of this application is to solve or at least alleviate some or all of the aforementioned problems. Therefore, one object of this application is to provide a battery pack and a method for determining its discharge capacity parameters, as well as a power tool system.
[0007] To achieve the above objectives, this application adopts the following technical solution:
[0008] A multi-pack electric device includes: an output unit; a power supply assembly including multiple battery pack interfaces configured to electrically connect the multiple battery packs; and a controller electrically connected to the power supply assembly, the controller being configured to: acquire operating parameters of the multiple battery packs respectively, the operating parameters including at least voltage; sort the multiple battery packs according to the operating parameters and determine the first battery pack with the strongest discharge capacity; determine the minimum voltage of the power supply assembly according to the discharge limit of the first battery pack; determine the required current for the multiple battery packs to discharge to the minimum voltage according to the minimum voltage; and sum the required currents of the multiple battery packs to obtain the maximum discharge current of the multi-pack electric device.
[0009] In one embodiment, the voltage of the first battery pack is greater than or equal to that of the remaining battery pack.
[0010] In one embodiment, if there are multiple battery packs with the highest voltage, the battery pack with the highest discharge limit is the first battery pack.
[0011] In one embodiment, the discharge limit of the first battery pack is determined based on the maximum discharge current of the first battery pack and the maximum allowable current of the channel in which the first battery pack is located.
[0012] In one embodiment, when the maximum discharge current of the first battery pack is greater than the maximum allowable current of the channel, the discharge limit of the first battery pack is the maximum allowable current of the channel.
[0013] In one embodiment, when the maximum discharge current of the first battery pack is less than or equal to the maximum allowable current of the channel, the discharge limit of the first battery pack is the maximum discharge current of the first battery pack.
[0014] In one embodiment, the discharge voltage of the first battery pack after being discharged according to the discharge limit is calculated based on the voltage and internal resistance of the first battery pack, and is taken as the minimum voltage.
[0015] In one embodiment, when the lowest voltage is higher than the voltage of one of the multiple battery packs, the required current for that battery pack is 0.
[0016] In one embodiment, when the lowest voltage is lower than the cutoff voltage of one of the multiple battery packs, the required current for that battery pack is the current required to discharge to the cutoff voltage.
[0017] In one embodiment, the maximum allowable current of the channel containing the battery pack is determined based on the circuit hardware capability of the battery pack's discharge current path.
[0018] In one embodiment, the multiple package of electric equipment is a ride-on lawnmower.
[0019] In one embodiment, multiple battery packs are connected in parallel.
[0020] In one embodiment, the battery pack is a removable battery pack or a built-in cell module.
[0021] A multi-pack electric device includes: an output unit; a power supply assembly including multiple battery pack interfaces configured to electrically connect the multiple battery packs; and a controller electrically connected to the power supply assembly, the controller being configured to: acquire operating parameters of the multiple battery packs respectively, the operating parameters including at least voltage and maximum discharge current of the battery packs; determine the discharge limit of each battery pack based on the maximum discharge current of each battery pack and the maximum allowable current of the channel it belongs to; determine the discharge voltage of each battery pack after discharging according to the discharge limit based on the voltage of each battery pack; determine the minimum voltage of the power supply assembly based on the discharge voltage of the multiple battery packs; determine the current required for the multiple battery packs to discharge to the minimum voltage based on the minimum voltage; and sum the required current of the multiple battery packs to obtain the maximum discharge current of the multi-pack electric device.
[0022] In one embodiment, the lowest voltage is the highest value of the discharge voltage of the multiple battery packs.
[0023] In one embodiment, when the maximum discharge current of the battery pack is greater than the maximum allowable current of the channel, the discharge limit of the battery pack is the maximum allowable current of the channel.
[0024] In one embodiment, when the maximum discharge current of the battery pack is less than or equal to the maximum allowable current of the channel, the discharge limit of the battery pack is the maximum discharge current of the battery pack.
[0025] A multi-pack electric device includes: an output unit; a power supply assembly including multiple battery pack interfaces configured to electrically connect the multiple battery packs; and a controller electrically connected to the power supply assembly, configured to: acquire the voltages of the multiple battery packs respectively; sort the voltages of the multiple battery packs to determine the high-voltage battery pack with the highest voltage; compare the discharge current required for the high-voltage battery pack to discharge to the next voltage value with the maximum allowable current of the channel where the high-voltage battery pack is located to determine the minimum voltage of the power supply assembly; determine the current required for the multiple battery packs to discharge to the minimum voltage based on the minimum voltage; and sum the required currents of the multiple battery packs to obtain the maximum discharge current of the multi-pack electric device.
[0026] In one embodiment, when the discharge current required for the high-voltage battery pack to discharge to the next voltage value is greater than the maximum allowable current of the channel, the battery pack with a voltage less than or equal to the next voltage value cannot participate in the discharge.
[0027] In one embodiment, when the discharge current required for the high-voltage battery pack to discharge to the next voltage value is less than or equal to the maximum allowable current of the channel, the battery pack with a voltage equal to the next voltage value can participate in the discharge and compare the next voltage value.
[0028] In one embodiment, when the discharge current required for the high-voltage battery pack to discharge to the next voltage value is greater than the maximum allowable current of the channel, the minimum voltage is equal to the discharge voltage of the high-voltage battery pack after discharging with the maximum allowable current of the channel.
[0029] In one embodiment, when there are no more battery packs to compare, the minimum voltage is equal to the cutoff voltage of the high-voltage battery pack.
[0030] The advantage of this application is that it comprehensively considers the discharge capacity of multiple battery packs themselves and the constraints of other hardware performance, making it easier for multi-pack electric devices to discharge according to the discharge capacity of multiple battery packs and the discharge capacity limit of the overall system. Attached Figure Description
[0031] Figure 1 is a structural diagram of a multi-pack electric device provided in an embodiment of this application;
[0032] Figure 2 is a partial structural diagram of the multi-pack electric device shown in Figure 1;
[0033] Figure 3 is a structural diagram of another multi-pack electric device provided in an embodiment of this application;
[0034] Figure 4 is a structural diagram of another configuration of the multi-pack electric equipment shown in Figure 3;
[0035] Figure 5 is a structural diagram of another multi-pack electric device provided in an embodiment of this application;
[0036] Figure 6 is a schematic diagram of a method for determining the maximum discharge current of a multi-pack electric device according to an embodiment of this application;
[0037] Figure 7 is a flowchart of a method for determining the maximum discharge current of a multi-pack electric device according to an embodiment of this application;
[0038] Figure 8 is a flowchart of another method for determining the maximum discharge current of a multi-pack electric device provided in an embodiment of this application;
[0039] Figure 9 is a flowchart of another method for determining the maximum discharge current of a multi-pack electric device provided in an embodiment of this application;
[0040] Figure 10 is a graph showing the maximum discharge current of a multi-pack electric device provided in an embodiment of this application. Detailed Implementation
[0041] Before explaining any implementation of this application in detail, it should be understood that this application is not limited to its application to the structural details and component arrangements set forth in the following description or shown in the above drawings.
[0042] In this application, the terms "comprising," "including," "having," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.
[0043] In this application, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this application generally indicates that the preceding and following related objects have an "and / or" relationship.
[0044] In this application, the terms "connection," "combination," "coupling," and "installation" can refer to direct connection, combination, coupling, or installation, or indirect connection, combination, coupling, or installation. For example, a direct connection refers to two parts or components being connected together without the need for an intermediary, while an indirect connection refers to two parts or components each being connected to at least one intermediary, with the connection achieved through the intermediary. Furthermore, "connection" and "coupling" are not limited to physical or mechanical connections or couplings, but can also include electrical connections or couplings.
[0045] In this application, those skilled in the art will understand that relative terms (e.g., “about,” “approximately,” “basically,” etc.) used in conjunction with quantities or conditions are to include the values and have the meaning indicated by the context. For example, such relative terms include at least the degree of error associated with the measurement of a particular value, tolerances associated with the particular value due to manufacturing, assembly, use, etc. Such terms should also be considered as disclosing a range defined by the absolute values of the two endpoints. Relative terms may refer to a certain percentage (e.g., 1%, 5%, 10% or more) of the indicated value. Numerical values that do not use relative terms should also be disclosed as specific values with tolerances. Furthermore, “basically” when expressing relative angular relationships (e.g., substantially parallel, substantially perpendicular) may refer to a certain degree (e.g., 1 degree, 5 degrees, 10 degrees or more) added to or subtracted from the indicated angle.
[0046] In this application, those skilled in the art will understand that the function performed by a component can be performed by one component, multiple components, one part, or multiple parts. Similarly, the function performed by a part can also be performed by one part, one component, or a combination of multiple parts.
[0047] In this application, the directional terms "upper," "lower," "left," "right," "front," and "rear" are used to describe the orientation and positional relationships shown in the accompanying drawings and should not be construed as limiting the embodiments of this application. Furthermore, in the context, it should be understood that when an element is mentioned as being connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected through an intermediate element. It should also be understood that directional terms such as upper side, lower side, left side, right side, front side, and rear side not only represent positive orientation but can also be understood as lateral orientation. For example, "below" can include directly below, lower left, lower right, lower front, and lower rear.
[0048] In this application, the terms "controller control module", "processor", "central processing unit", "CPU", and "MCU" are used interchangeably. When using the unit "controller", "processor", "central processing unit", "CPU", or "MCU" to perform a specific function, unless otherwise stated, these functions may be performed by a single or multiple of the aforementioned units.
[0049] In this application, the terms "device," "module," or "unit" are used to describe devices that can be implemented in hardware or software to perform a specific function.
[0050] In this application, the terms “calculation,” “judgment,” “control,” “determine,” “identify,” etc., refer to the operation and process of a computer system or similar electronic computing device (e.g., controller, processor, etc.).
[0051] To clearly illustrate the technical solution of this application, the terms "upper side", "lower side", "left side", "right side", "front side" and "rear side" are defined in the accompanying drawings.
[0052] The embodiments of this application are described in detail below with reference to the illustrations. The multi-pack electric equipment of this application can be large power tools such as lawnmowers and snowplows, or outdoor mobility devices such as electric all-terrain vehicles, especially large power tools with mobility functions such as ride-on lawnmowers. It can also be a device like an energy station that directly outputs electrical energy instead of converting it into mechanical energy; or a device like a floor lamp that converts electrical energy into light energy. The multi-pack electric equipment includes at least a power supply component, an output unit, and a controller. The power supply component provides energy in the form of electrical energy. In this application, the power supply component is a DC power supply component, including multiple battery pack interfaces, each for electrically connecting one battery pack. The output unit outputs the electrical energy provided by the power supply component to realize the intended function of the multi-pack electric equipment. The controller is used to control the multi-pack electric equipment. In this application, the controller is configured to determine the maximum discharge capacity (State of Power, SOP) of the multi-pack electric equipment and control the discharge of the power supply component based on the maximum discharge capacity. The controller can be a dedicated Energy Management System (EMS) or a comprehensive controller for the entire machine.
[0053] As shown in Figure 1, the ride-on lawnmower 100 includes: a cutting assembly 10, a housing system 20, a power supply assembly 30, a frame 91, a seat 92, a walking assembly 93, a lighting system 40, and an operating assembly 50. In this embodiment, the power supply assembly 30 provides electrical energy to the various components of the ride-on lawnmower 100, thereby enabling the ride-on lawnmower 100 to be used as an electric tool. The cutting assembly 10, the walking assembly 93, and the lighting system 40 are all output units. Compared to fuel-powered ride-on lawnmowers 100, this electric ride-on lawnmower 100 is more environmentally friendly and energy-efficient.
[0054] The power supply assembly 30 provides power to the cutting assembly 10, the walking assembly 93, the lighting system 40, etc. The power supply assembly 30 includes multiple battery packs 31. The power supply assembly 30 can be located at the rear of the ride-on lawnmower 100, mounted on the frame 91. In one embodiment, the power supply assembly 30 is located behind the seat 92. In one embodiment, referring to FIG. 2, the power supply assembly 30 includes six battery packs 31 (shown in dashed outlines). These six battery packs 31 are arranged in three rows along the front-to-back direction, with each row including two battery packs 31 arranged in the left-to-right direction. The ride-on lawnmower 100 also includes a controller 60 for determining the maximum discharge capacity (SOP) of the entire machine. In one embodiment, the controller 60 is located on the battery management circuit board 964; in another embodiment, the controller 60 is located on the vehicle controller 95. The power supply assembly 30 also includes multiple battery pack interfaces, which can be configured as connection terminals 963. Six battery packs 31 are connected to the battery management circuit board 964 through the connection terminals 963, and the battery management circuit board 964 manages the charging and discharging of the power supply assembly 30.
[0055] As shown in Figures 3 and 4, in another layout of the ride-on lawnmower 100, the power assembly 30 can also be located at the front of the ride-on lawnmower 100 and covered by the front cover 232 of the ride-on lawnmower 100. The power assembly 30 of the ride-on lawnmower 100 shown in Figure 3 includes six removable battery packs 311; the power assembly 30 of the ride-on lawnmower 100 shown in Figure 4, in addition to including the removable battery packs 311 (the battery packs 311 are removed in the figure, and the battery compartment 313 is visible), also includes an internal battery cell module 312. In this case, the controller 60 is used to manage the coordinated discharge of the removable battery packs 311 and the internal battery cell module 312.
[0056] As shown in Figure 5, the multi-pack electric device is an electric all-terrain vehicle 100. In one embodiment, the power supply assembly 30 can be located under the seat 92; the power supply assembly includes multiple built-in battery cell modules 312. Note that the term "non-removable" in this application refers to the inability of a user to remove it from its installed state without tools, not that maintenance personnel cannot remove the built-in battery cell modules from their installed state even with the aid of professional tools, as this would be detrimental to the maintenance and upkeep of the multi-pack electric device. Conversely, the term "removable" in this application means that a user can remove the battery pack from its installed state without tools. This allows the user to easily remove the battery pack for charging, replace a low-charge battery pack with a high-charge one, or replace a faulty battery pack with a healthy one. In this application, both the removable battery pack 311 and the built-in battery cell modules 312 are battery packs 31.
[0057] As shown in Figure 6, multiple battery packs in a multi-pack electric device are discharged in parallel. These battery packs have different states of charge (SOC) and voltages, which may be due to user replacement of the battery packs or differences in the aging of the battery packs themselves. Correspondingly, the maximum discharge capacity (SOP) of each battery pack may also differ. Maximum discharge capacity can be expressed by maximum discharge current or maximum discharge power, where maximum discharge current is the current required to discharge the battery pack from its current voltage to its cutoff voltage. The maximum discharge capacity of each battery pack can be calculated by obtaining its voltage and internal resistance. Specifically, the maximum discharge current of the battery pack can be obtained by dividing the difference between the current voltage and the cutoff voltage by the internal resistance of the battery pack. Other more complex and precise methods for calculating maximum discharge capacity can be found in our patent application No. 202411507849.8, and will not be detailed here. The maximum discharge capacity of a multi-pack electric device as a whole is related not only to the performance of each battery pack but also to the constraints of the hardware circuitry.
[0058] When multiple battery packs connected in parallel have inconsistent voltages, only one or more battery packs with the highest voltage levels can participate in the discharge process. For example, battery pack 1 currently has a voltage of 54V, battery packs 2 and 3 currently have a voltage of 53V, battery pack 4 currently has a voltage of 50V, battery pack 5 currently has a voltage of 49V, and battery pack 6 currently has a voltage of 48V. Initially, only battery pack 1 can discharge. When the voltage of battery pack 1 drops to 53V, battery packs 2 and 3 can then participate in the discharge, at which point battery packs 1, 2, and 3 discharge together. When the voltages of battery packs 1, 2, and 3 all drop to 50V, battery pack 4 can then participate in the discharge. However, not all battery packs will ultimately participate in the discharge. In one scenario, the discharge cutoff voltage of this battery pack is 48V. Battery pack 6 has already reached its discharge cutoff voltage, and even if other battery packs continue to discharge to lower their voltage, battery pack 6 cannot participate in the discharge. In another scenario, even if the voltage of a battery pack has not yet reached its cutoff voltage, due to the large voltage difference between it and the high-voltage battery pack, and the overcurrent capability limitation of the hardware in the channel where the high-voltage battery pack is located, the high-voltage battery pack cannot be pulled down to the same voltage level in a short time. Therefore, this low-voltage battery pack cannot participate in the discharge. In other words, although it still has current remaining, the current it could release under suitable conditions cannot be included in the calculation of the maximum discharge current of the entire device. Taking the example above, the voltage difference between battery pack 1 and battery pack 5 is large. Assuming the maximum allowable current of the channel where battery pack 1 is located is 50A, and the internal resistance of battery pack 1 is less than 0.1 ohms (e.g., 0.09 ohms), then the current required to pull battery pack 1 down to the voltage level of battery pack 5 is greater than 50A, exceeding the maximum allowable current of the channel where battery pack 1 is located. Therefore, battery pack 5 cannot participate in the discharge.
[0059] The above assumes that the multiple battery packs are identical, with the same cutoff voltage. Therefore, the current required to bring the high-voltage battery pack to the voltage level of the low-voltage battery pack will not exceed its own maximum discharge current. If the battery packs are different, for example, with different cutoff voltages, if the cutoff voltage of the high-voltage battery pack is higher than the current voltage of the low-voltage battery pack, then the low-voltage battery pack cannot participate in discharging. In other words, due to the voltage difference between the high-voltage and low-voltage battery packs, and limited by the discharge capacity of the high-voltage battery pack itself, the high-voltage battery pack cannot be pulled down to the same voltage level, which will also prevent the low-voltage battery pack from participating in discharging.
[0060] Referring to Figure 7, in one embodiment, the controller can determine the maximum discharge current of the multi-pack electric device through the following steps.
[0061] S110: Obtain the operating parameters of multiple battery packs respectively.
[0062] The operating parameters of the battery pack are calculated from the data detected by the detection components. The detection components can be entirely located within the battery pack and transmitted to the controller via the battery pack interface; alternatively, they can be partially located within the battery pack and partially within the multi-pack electric device; or they can be entirely located within the multi-pack electric device. Commonly detected data includes the voltage, current, and temperature of the battery pack (i.e., battery pack 1 or cell module 25). Therefore, the detection component 11 can include voltage sensors, current sensors, and temperature sensors. The battery pack can determine its voltage and internal resistance based on the detected data, thereby calculating the maximum discharge current of the battery pack; alternatively, the detected data can be sent to the controller, which will then calculate the operating parameters of each battery pack.
[0063] S120. Sort multiple battery packs according to working parameters and determine the first battery pack with the strongest discharge capacity.
[0064] As mentioned earlier, when multiple battery packs are connected in parallel, discharge begins with one or more packs with the highest voltage. Therefore, it is necessary to first identify the battery pack with the strongest discharge capacity, referred to as the first battery pack. The voltage of the first battery pack is greater than or equal to that of the remaining battery packs. If multiple battery packs have the highest voltage, the one with the highest discharge limit is the first battery pack. The discharge limit represents the maximum discharge capacity of the first battery pack and its channel as a whole. The discharge limit of each battery pack is defined by the smaller of the maximum discharge current of that battery pack and the maximum allowable current of the channel in which that battery pack is located. The maximum allowable current of the channel in which the battery pack is located can be obtained through a preset value or by communicating with relevant detection elements. The discharge limit of the first battery pack determines whether other battery packs can participate in the discharge, which is included in the calculation of the maximum discharge current of the entire device.
[0065] S130. Determine the minimum voltage of the power supply component based on the discharge limit of the first battery pack.
[0066] The discharge limit of the first battery pack is determined based on its maximum discharge current and the maximum allowable current of the channel it belongs to. When the maximum discharge current of the first battery pack is greater than or equal to the maximum allowable current of the channel, the first battery pack undergoes a limit discharge at the maximum allowable current of the channel. When the maximum discharge current of the first battery pack is less than the maximum allowable current of the channel, the first battery pack undergoes a limit discharge at its own maximum discharge current. After the first battery pack discharges at the maximum discharge current that it and the channel can jointly withstand, the voltage of the first battery pack is the minimum voltage of the power supply assembly. Specifically, the discharge voltage of the first battery pack after its limit discharge can be calculated based on its voltage and internal resistance. It should be noted that the minimum voltage here refers to the minimum voltage of the battery packs in the power supply assembly that can participate in the discharge; there may be battery packs in the power supply assembly with voltage levels lower than the minimum voltage that cannot participate in the discharge. Although low-voltage battery packs still have current remaining, their current cannot be included in the calculation of the maximum discharge current of the entire unit.
[0067] S140. Based on the minimum voltage, determine the current required for each battery pack to discharge to the minimum voltage.
[0068] Based on the internal resistance of each battery pack, the current required for each battery pack to discharge from its current voltage to its minimum voltage can be calculated. When the minimum voltage is higher than the voltage of a particular battery pack, that battery pack does not participate in the discharge, and the required current is 0. Under normal circumstances, all battery packs are identical, have the same cutoff voltage, and the minimum voltage will not be lower than the cutoff voltage of each battery pack. However, in some cases, battery packs differ, and their cutoff voltages also differ. When the minimum voltage is lower than the cutoff voltage of a battery pack, the required current for that battery pack is the current required to discharge to its own cutoff voltage. In this situation, this battery pack participates in a period of discharge, but because it reaches its cutoff voltage first, it stops discharging.
[0069] S150: Accumulate the required current of multiple battery packs to obtain the maximum discharge current of the multi-pack electric device.
[0070] Based on the above method, the controller can calculate the battery packs that can participate in the discharge and the current they can each contribute. By summing these values, the maximum discharge current of the entire multi-pack electric device can be obtained, and the discharge of each component can be arranged accordingly.
[0071] Referring to Figure 8, this application provides a more specific process for determining the maximum discharge current of a multi-pack electric device. It is assumed that the multi-pack electric device contains N battery packs, each with one discharge channel.
[0072] S210: Obtain the voltage of N battery packs from channel 1 to channel N, the maximum discharge current CurBat of each battery pack, and the maximum allowable current CurPcb of each channel.
[0073] This step is similar to S110 and will not be described in detail here.
[0074] S220. Compare the maximum discharge current of the battery pack, CurBat, with the maximum allowable current of its channel, CurPcb, to determine the discharge limit, CurMax, for each battery pack.
[0075] When the maximum permissible current CurPcb of a battery pack channel is greater than the maximum discharge current CurBat of that battery pack, the battery pack can perform a limit discharge at its maximum discharge current CurBat.
[0076] S230. Calculate the discharge voltage VolDsg reached by each battery pack under the discharge limit CurMax.
[0077] Based on the voltage, internal resistance, and the current value of the discharge limit CurMax obtained in the previous step, determine the discharge voltage of each battery pack after extreme discharge. Theoretically, the discharge voltage of each battery pack should be greater than or equal to its cutoff voltage.
[0078] S240: Obtain the highest value of the discharge voltage VolDsg for each battery pack, VolMax.
[0079] The highest discharge voltage of each battery pack, VolMax, is the lowest voltage that the power supply component can discharge. In other words, battery packs with a current voltage, Vol, that is lower than the highest value, VolMax, cannot participate in the discharge process.
[0080] S250, Calculate the current CurAx required for each battery pack to discharge to its maximum value VolMax.
[0081] In this step, the current voltage Vol of the battery pack can be compared with the maximum value VolMax. When the current voltage Vol of the battery pack is lower than the maximum value VolMax, the battery pack in this channel does not participate in the overall discharge, and the required current CurAx is 0. When the current voltage Vol of the battery pack is greater than or equal to the maximum value VolMax, the required current CurAx can be calculated based on the difference between the current voltage Vol and the maximum value VolMax, as well as the internal resistance of the battery pack.
[0082] S260, sum the required currents CurAx of multiple battery packs to obtain the maximum discharge current of the multi-pack electric device.
[0083] Referring to Figure 9, this application also provides another specific process method for determining the maximum discharge current of a multi-pack electric device. Assume the multi-pack electric device comprises N battery packs, each with one discharge channel. In one embodiment, the N battery packs are identical, with the same cutoff voltage VolCut.
[0084] S310: Obtain the voltages of N battery packs from channels 1 to N.
[0085] This step is similar to S110 and will not be described in detail here.
[0086] S320: Sort the battery packs by voltage in descending order and determine the high-voltage battery pack with the highest voltage.
[0087] The system sorts the data to obtain the highest voltage value and its corresponding battery pack, the second highest voltage value and its corresponding battery pack, and so on. One voltage value may correspond to multiple battery packs. Multiple battery packs with the same voltage value can be discharged together. Note that a high-voltage battery pack may consist of more than one battery pack.
[0088] S330 compares the discharge current CurNx required for the high-voltage battery pack to discharge to the next voltage value with the maximum allowable current CurMax of the channel where the high-voltage battery pack is located.
[0089] The purpose of this step is to find a battery pack that can participate in the discharge. Specifically, the required discharge current CurNx is equal to the voltage difference between the highest voltage value and the next voltage value divided by the internal resistance of the high-voltage battery pack.
[0090] When the discharge current CurNx required for the high-voltage battery pack to discharge to the next voltage value is greater than the maximum allowable current CurMax of the channel, it means that the battery pack with a voltage equal to the next voltage value cannot participate in the discharge, and other battery packs with lower voltages also cannot participate in the discharge, proceeding to step S360.
[0091] When the discharge current CurNx required for the high-voltage battery pack to discharge to the next voltage value is less than or equal to the channel's maximum allowable current CurMax, it indicates that the battery pack with the voltage equal to the next voltage value can participate in discharge; at this point, the comparison continues to the next voltage value. The meaning of step-by-step comparison is that the voltage values being compared decrease, and the voltage values come from the voltage sorting in S320.
[0092] When no more voltage values need to be compared, it means that all battery packs are able to participate in the discharge, and proceed to step S340.
[0093] S340. Calculate the current CurCut required for each channel's discharge voltage to reach the cutoff voltage VolCut.
[0094] If step S330 compares the voltages of the high-voltage battery pack and all other battery packs, and the discharge current CurNx required for the high-voltage battery pack to discharge to the voltages of all other battery packs is less than or equal to the maximum allowable current CurMax of the channel containing the high-voltage battery pack, then all battery packs can participate in the discharge. The lowest voltage that the power supply assembly can be discharged to is the cutoff voltage VolCut of each battery pack.
[0095] S350: Accumulate the current CurCut required when the discharge voltage of each battery pack reaches the cutoff voltage VolCut, and obtain the maximum discharge current of the multi-pack electric device.
[0096] S360. Calculate the voltage VolA when the maximum channel current of CurNx is CurMax.
[0097] When the discharge current CurNx required for a high-voltage battery pack to discharge to the next voltage value exceeds the maximum allowable current CurMax of the channel containing the first battery pack, it indicates that due to hardware circuit limitations, at least one high-voltage battery pack's voltage cannot be lowered to the next voltage value. Among these, the high-voltage battery pack with the largest discharge current CurNx required to discharge to the next voltage value is the battery pack with the strongest discharge capacity. Similar to S130, the minimum voltage of the power supply component can be determined based on the discharge limit of this battery pack. Because the discharge current CurNx required for this high-voltage battery pack to discharge to the next voltage value exceeds the maximum allowable current CurMax of its channel, the discharge voltage VolA after the high-voltage battery pack discharges can be directly determined based on the maximum allowable current CurMax of that channel, and used as the minimum voltage of the power supply component.
[0098] S370. Calculate the current CurAx required for the other channels included in the calculation to discharge to the lowest voltage VolA of the power supply component.
[0099] Similar to S140, once the minimum voltage of the power supply component is determined, the current CurAx required for each battery pack to discharge to its minimum voltage can be calculated. In this process, the battery packs that can participate in the discharge are pre-determined in step S370, so only the current CurAx required for these battery packs to discharge to the minimum voltage VolA of the power supply component can be calculated.
[0100] S380, sum the required current CurAx of multiple battery packs to obtain the maximum discharge current of the multi-pack electric device.
[0101] Using the above methods, the maximum discharge current and power status of multi-pack electric equipment can be accurately predicted, and it can be determined whether the current multi-pack system can meet the power requirements of the whole machine. This helps the whole machine to perform power control, ensuring the continuous and stable operation of the whole machine while reducing the over-discharge of the battery pack (see Figure 10).
[0102] This application also provides a method for calculating the state of charge (SOC) of a multi-pack system. The overall SOC of the multiple packs is the sum of the remaining capacity of each pack divided by the sum of the maximum capacity of each pack, where the remaining capacity is the maximum capacity of a single pack multiplied by its single-pack SOC. The calculation method for the single-pack SOC and maximum capacity can be found in our patent application No. 202411509221.1, and will not be detailed here. The relative SOC proposed in that patent application is the ratio of the remaining dischargeable capacity of the battery under the current operating conditions to the maximum dischargeable capacity of the battery under the current operating conditions, which helps users understand the expected operation of the battery pack under the current operating conditions. The above-mentioned multi-pack SOC is more accurate than the SOC estimated by conventional methods, providing better support for the implementation of power display and regression functions, and helping to improve the user experience.
[0103] The foregoing has shown and described the basic principles, main features, and advantages of this application. Those skilled in the art should understand that the above embodiments do not limit this application in any way, and all technical solutions obtained by equivalent substitution or equivalent transformation fall within the protection scope of this application.
Claims
1. A multi-package electric device (100), comprising: Output unit; A power supply assembly (30) includes multiple battery pack interfaces configured to electrically connect multiple battery packs (31). Controller (60), electrically connected to the power supply assembly, wherein controller (60) is configured to: The operating parameters of the plurality of battery packs are obtained respectively, and the operating parameters include at least voltage; The multiple battery packs are sorted according to the operating parameters to determine the first battery pack with the strongest discharge capacity. The minimum voltage of the power supply component is determined based on the discharge limit of the first battery pack. Based on the minimum voltage, determine the required current for the plurality of battery packs to discharge to the minimum voltage; and The maximum discharge current of the multi-pack electric device is obtained by summing the required current of the multiple battery packs.
2. The multi-pack electric device (100) according to claim 1, characterized in that, The voltage of the first battery pack is greater than or equal to that of the remaining battery pack.
3. The multi-pack electric device (100) according to claim 1, characterized in that, If there are multiple battery packs with the highest voltage, the battery pack with the highest discharge limit is the first battery pack.
4. The multi-pack electric device (100) according to claim 3, characterized in that, The discharge limit of the first battery pack is determined based on the maximum discharge current of the first battery pack and the maximum allowable current of the channel in which the first battery pack is located.
5. The multi-pack electric device (100) according to claim 4, characterized in that, When the maximum discharge current of the first battery pack is greater than the maximum allowable current of the channel, the discharge limit of the first battery pack is the maximum allowable current of the channel.
6. The multi-pack electric device (100) according to claim 4, characterized in that, When the maximum discharge current of the first battery pack is less than or equal to the maximum allowable current of the channel, the discharge limit of the first battery pack is the maximum discharge current of the first battery pack.
7. The multi-pack electric device (100) according to claim 1, characterized in that, Based on the voltage and internal resistance of the first battery pack, the discharge voltage of the first battery pack after discharge according to the discharge limit is calculated and used as the minimum voltage.
8. The multi-pack electric device (100) according to claim 1, characterized in that, When the minimum voltage is higher than the voltage of one of the multiple battery packs, the required current for that battery pack is 0.
9. The multi-pack electric device (100) according to claim 1, characterized in that, When the minimum voltage is lower than the cutoff voltage of one of the plurality of battery packs, the required current for that battery pack is the current required to discharge to the cutoff voltage.
10. The multi-pack electric device (100) according to claim 4, characterized in that, The maximum allowable current of the channel where the battery pack is located is determined based on the circuit hardware capability of the discharge current path of the battery pack.
11. The multi-pack electric device (100) according to claim 1, characterized in that, The aforementioned multi-pack electric equipment is a ride-on lawnmower.
12. The multi-pack electric device (100) according to claim 1, characterized in that, The multiple battery packs are connected in parallel.
13. The multi-pack electric device (100) according to claim 1, characterized in that, The battery pack is either a detachable battery pack or a built-in cell module.
14. A multi-package electric device (100), comprising: Output unit; A power supply assembly (30) includes multiple battery pack interfaces configured to electrically connect multiple battery packs (31). Controller (60), electrically connected to the power supply assembly, wherein controller (60) is configured to: The operating parameters of the plurality of battery packs are obtained respectively, and the operating parameters include at least voltage and the maximum discharge current of the battery pack; The discharge limit of each battery pack is determined based on the maximum discharge current of each battery pack and the maximum allowable current of the channel in which it is located. The discharge voltage of each battery pack after discharge according to the discharge limit is determined based on the voltage of each battery pack. The minimum voltage of the power supply component is determined based on the discharge voltage of the plurality of battery packs; Based on the minimum voltage, determine the required current for the plurality of battery packs to discharge to the minimum voltage; and The maximum discharge current of the multi-pack electric device is obtained by summing the required current of the multiple battery packs.
15. The multi-pack electric device (100) according to claim 14, characterized in that, The minimum voltage is the highest value of the discharge voltage of the plurality of battery packs.
16. The multi-pack electric device (100) according to claim 14, characterized in that, When the maximum discharge current of the battery pack is greater than the maximum allowable current of the channel, the discharge limit of the battery pack is the maximum allowable current of the channel.
17. The multi-pack electric device (100) according to claim 14, characterized in that, When the maximum discharge current of the battery pack is less than or equal to the maximum allowable current of the channel, the discharge limit of the battery pack is the maximum discharge current of the battery pack.
18. A multi-package electric device (100), comprising: Output unit; A power supply assembly (30) includes multiple battery pack interfaces configured to electrically connect multiple battery packs (31). Controller (60), electrically connected to the power supply assembly, wherein controller (60) is configured to: The voltages of the plurality of battery packs are obtained respectively; The voltages of the multiple battery packs are sorted to determine the high-voltage battery pack with the highest voltage. The minimum voltage of the power supply component is determined by comparing the discharge current required for the high-voltage battery pack to discharge to the next voltage value with the maximum allowable current of the channel where the high-voltage battery pack is located. Based on the minimum voltage, determine the required current for the plurality of battery packs to discharge to the minimum voltage; and The maximum discharge current of the multi-pack electric device is obtained by summing the required current of the multiple battery packs.
19. The multi-pack electric device (100) according to claim 18, characterized in that, When the discharge current required for the high-voltage battery pack to discharge to the next voltage value is greater than the maximum allowable current of the channel, the battery pack with a voltage less than or equal to the next voltage value cannot participate in the discharge.
20. The multi-pack electric device (100) according to claim 18, characterized in that, When the discharge current required for the high-voltage battery pack to discharge to the next voltage value is less than or equal to the maximum allowable current of the channel, the battery pack with a voltage equal to the next voltage value can participate in the discharge and compare the next voltage value.
21. The multi-pack electric device (100) according to claim 18, characterized in that, When the discharge current required for the high-voltage battery pack to discharge to the next voltage value is greater than the maximum allowable current of the channel, the minimum voltage is equal to the discharge voltage of the high-voltage battery pack after discharging with the maximum allowable current of the channel.
22. The multi-pack electric device (100) according to claim 18, characterized in that, When there are no more battery packs to compare, the minimum voltage is equal to the cutoff voltage of the high-voltage battery pack.