Hybrid battery pack control method, hybrid battery pack, electric vehicle

Abstract

The application discloses a mixed battery pack control method, a mixed battery pack and an electric vehicle. The mixed battery pack control method is applied to the electric vehicle, the electric vehicle comprises the mixed battery pack, the mixed battery pack comprises a plurality of battery packs, at least one battery pack in the plurality of battery packs is of a type different from those of other battery packs, and the mixed battery pack control method comprises the following steps: obtaining battery pack parameters of the plurality of battery packs and / or working condition parameters of the electric vehicle, determining a target working mode of the mixed battery pack according to the working condition parameters and / or the plurality of battery parameters, and controlling corresponding types of battery packs in the plurality of battery packs to perform corresponding charging and discharging work according to the target working mode. The application aims to improve the use performance of the mixed battery pack.

Description

Technical Field

[0001] The present invention relates to the technical field of battery packs, and in particular to a hybrid battery pack control method, a hybrid battery pack, and an electric vehicle. Background Art

[0002] Due to the differences in self-discharge rate, cycle attenuation trend, rate discharge capability and high and low temperature discharge capability of different system batteries, the battery performance will have a short-board effect. Not only can the performance advantages of different system batteries not be brought into play, but the performance indicators of the A+B battery pack will all be aligned with the worse ones. Summary of the Invention

[0003] The main purpose of the present invention is to provide a hybrid battery pack control method, a hybrid battery pack, and an electric vehicle, aiming to improve the performance of the hybrid battery pack.

[0004] To achieve the above objectives, the present invention proposes a hybrid battery pack control method, which is applied to an electric vehicle. The electric vehicle includes a hybrid battery pack, and the hybrid battery pack includes multiple battery packs. At least one of the multiple battery packs is of a different type from the other battery packs. The hybrid battery pack control method includes:

[0005] Acquiring battery pack parameters of a plurality of the battery packs and / or operating parameters of the electric vehicle;

[0006] Based on the operating parameters and / or multiple battery parameters, the target operating mode of the mixed battery pack is determined, and the corresponding types of battery packs in the multiple battery packs are controlled to form corresponding charging and discharging circuits according to the target operating mode to perform corresponding charging and discharging operations.

[0007] Optionally, the hybrid battery pack further comprises a heating device and a charging terminal, and the battery pack parameters include battery pack temperature parameters;

[0008] The steps of determining a target operating mode of the mixed battery pack according to the operating condition parameters and / or the plurality of battery parameters, and controlling the battery packs of corresponding types among the plurality of battery packs to form corresponding charge and discharge circuits according to the target operating mode to perform corresponding charge and discharge operations are specifically as follows:

[0009] According to the operating parameters of the electric vehicle and / or the temperature parameters of the multiple battery packs, it is determined that the electric vehicle is in a charging state, and when the temperatures of the multiple battery packs are currently lower than a preset low temperature, the mixed battery pack is controlled to enter a low-temperature charging mode. In the low-temperature charging mode, the battery pack of a type matching the low-temperature charging mode is controlled to be connected to the charging end for charging; and the heating device is controlled to be connected to the charging end to enable the heating device to work.

[0010] Optionally, after the step of controlling the heating device to connect to the corresponding battery pack so that the heating device works, the method further includes:

[0011] When it is determined according to the temperature parameters of the battery packs that the temperatures of the current plurality of battery packs reach a preset normal temperature, the remaining one or more battery packs are controlled to be connected to the charging end for charging.

[0012] Optionally, the hybrid battery pack further comprises a heating device and a discharge terminal, and the battery pack parameters include battery pack temperature parameters;

[0013] The steps of determining a target operating mode of the mixed battery pack according to the operating condition parameters and / or the plurality of battery parameters, and controlling the battery packs of corresponding types among the plurality of battery packs to form corresponding charge and discharge circuits according to the target operating mode to perform corresponding charge and discharge operations are specifically as follows:

[0014] According to the operating parameters of the electric vehicle and / or the temperature parameters of the multiple battery packs, it is determined that the electric vehicle is in a driving state, and when the temperatures of the multiple battery packs are currently lower than a preset low temperature, the hybrid battery pack is controlled to enter a low-temperature discharge mode. In the low-temperature discharge mode, the battery pack of a type matching the low-temperature discharge mode is controlled to be connected to the discharge end to discharge the electric vehicle; and the heating device is controlled to be connected to the corresponding battery pack to enable the heating device to work.

[0015] Optionally, after the step of controlling the heating device to connect to the corresponding battery pack so that the heating device works, the method further includes:

[0016] When it is determined based on multiple battery pack temperature parameters that the temperatures of the current multiple battery packs reach a preset normal temperature, the path between the battery pack of the type matching the low-temperature discharge mode and the discharge end is disconnected, and the remaining one or more battery packs are controlled to be connected to the discharge end to discharge the electric vehicle.

[0017] Optionally, the operating condition parameters of the electric vehicle include a target power parameter of the electric vehicle, the battery pack parameters include a power parameter, and the hybrid battery pack further has a discharge terminal. The steps of obtaining the battery pack parameters of the plurality of battery packs and / or the operating condition parameters of the electric vehicle are specifically as follows:

[0018] Obtaining a target power parameter of the electric vehicle and power parameters of the plurality of battery packs;

[0019] The steps of determining a target operating mode of the mixed battery pack according to the operating condition parameters and / or the plurality of battery parameters, and controlling the battery packs of corresponding types among the plurality of battery packs to form corresponding charge and discharge circuits according to the target operating mode to perform corresponding charge and discharge operations are specifically as follows:

[0020] When it is determined based on the target power parameters of the electric vehicle that the target power of the electric vehicle reaches the preset power, and it is determined based on the power parameters of the multiple battery packs that the power difference between the multiple battery packs does not reach the preset power difference, the mixed battery pack is controlled to enter the high-power discharge mode. In the high-power discharge mode, the multiple battery packs are controlled to be connected to the discharge end so that the multiple battery packs discharge the electric vehicle together.

[0021] Optionally, the step of determining a target operating mode of the hybrid battery pack according to the operating condition parameter and / or the plurality of battery parameters, and controlling the battery packs of corresponding types among the plurality of battery packs to form corresponding charge and discharge circuits according to the target operating mode to perform corresponding charge and discharge operations further includes:

[0022] When it is determined based on the target power parameters of the electric vehicle that the target power of the electric vehicle does not reach the preset power, the hybrid battery pack is controlled to enter the normal discharge mode. In the normal discharge mode, the battery pack of the type matching the normal discharge mode is controlled to be connected to the discharge end to discharge the electric vehicle.

[0023] Optionally, the hybrid battery pack further has a charging terminal, the operating condition parameters further include charging instructions, and the steps of obtaining the battery pack parameters of the plurality of battery packs and / or the operating condition parameters of the electric vehicle are specifically as follows:

[0024] Obtaining a charging instruction for the electric vehicle;

[0025] The steps of determining a target operating mode of the mixed battery pack according to the operating condition parameters and / or the plurality of battery parameters, and controlling the battery packs of corresponding types among the plurality of battery packs to form corresponding charge and discharge circuits according to the target operating mode to perform corresponding charge and discharge operations are specifically as follows:

[0026] When it is determined that the charging instruction of the electric vehicle is a fast charging instruction, the mixed battery pack is controlled to enter the fast charging mode. In the fast charging mode, the battery pack of the type matching the fast charging mode is controlled to be connected to the charging end for charging; and after charging is completed, the battery pack of the type matching the fast charging mode is controlled to be connected to the remaining one or more battery packs to charge the remaining battery packs.

[0027] The present invention also proposes a hybrid battery pack for use in electric vehicles, the hybrid battery pack comprising:

[0028] Multiple battery packs;

[0029] Memory;

[0030] a processor having a communication terminal for communicating with the electric vehicle;

[0031] Charging terminal;

[0032] discharge terminal;

[0033] switch array;

[0034] a hybrid battery pack control program stored in the memory and executed by the processor, wherein the hybrid battery pack control program, when executed by the processor, implements any of the above hybrid battery pack control methods;

[0035] The processor is electrically connected to the plurality of battery packs, the switch array, and the memory respectively; and the switch array is electrically connected to the plurality of battery packs, the discharge end, and the charge end respectively.

[0036] Optionally, the hybrid battery pack further includes:

[0037] A heating device is electrically connected to the switch array.

[0038] Optionally, there are multiple charging terminals, and all of the multiple charging terminals are electrically connected to the switch array;

[0039] The processor is further configured to receive a multi-gun charging instruction from the electric vehicle, and upon receiving the multi-gun charging instruction, control the switch array to operate so as to connect paths between the plurality of charging terminals and the plurality of battery packs in a one-to-one correspondence.

[0040] Optionally, the number of the battery packs is two, and the two battery packs are a ternary NCM battery pack and a lithium iron phosphate LFP battery pack.

[0041] Optionally, the hybrid battery pack further includes: a housing;

[0042] The ternary NCM battery pack is arranged on the inner wall of the shell;

[0043] The lithium iron phosphate (LFP) battery pack is disposed at the center of the housing.

[0044] The present invention also provides an electric vehicle comprising the hybrid battery pack described in any one of the above items.

[0045] In the solution of the present invention, the battery pack parameters of the multiple battery packs and / or the operating parameters of the electric vehicle are first obtained, and then the target operating mode of the mixed battery pack is determined based on the operating parameters and / or the multiple battery parameters, and the corresponding types of battery packs in the multiple battery packs are controlled to perform corresponding charging and discharging operations according to the target operating mode. In this way, during the actual use of the mixed battery packs, the corresponding types of battery packs can be controlled to form different charging and discharging circuits and perform corresponding charging and discharging operations based on the actual battery pack type and parameters and the operating status of the electric vehicle. Compared with the traditional charging and discharging operations of multiple battery packs connected in series and parallel, this avoids the short board effect caused by battery differences and effectively improves the performance of the mixed battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0047] Figure 1 A schematic diagram of a method flow chart of an embodiment of a hybrid battery pack control method of the present invention;

[0048] Figure 2 A schematic diagram of a method flow chart of another embodiment of a hybrid battery pack control method of the present invention;

[0049] Figure 3 This is a schematic diagram of a method flow of another embodiment of a hybrid battery pack control method of the present invention;

[0050] Figure 4 This is a schematic diagram of a method flow chart of another embodiment of a hybrid battery pack control method of the present invention;

[0051] Figure 5 A schematic diagram of a method flow chart of another embodiment of a hybrid battery pack control method of the present invention;

[0052] Figure 6 This is a schematic diagram of a method flow of another embodiment of a hybrid battery pack control method of the present invention;

[0053] Figure 7 This is a schematic diagram of a method flow chart of another embodiment of a hybrid battery pack control method of the present invention;

[0054] Figure 8 This is a schematic diagram of a method flow chart of another embodiment of a hybrid battery pack control method of the present invention;

[0055] Figure 9This is a schematic structural diagram of an embodiment of a hybrid battery pack of the present invention;

[0056] Figure 10 Schematic diagram of the structure of another embodiment of the hybrid battery pack of the present invention.

[0057] Description of Figure Numbers:

[0058] Label name Label name 10 Memory 20 processor 30 switch array 40 Heating device

[0059] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0060] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0061] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0062] Due to the differences in self-discharge rate, cycle attenuation trend, rate discharge capability and high and low temperature discharge capability of different system batteries, the battery performance will have a short-board effect. Not only can the performance advantages of different system batteries not be brought into play, but the performance indicators of the A+B battery pack will all be aligned with the worse ones.

[0063] To this end, the present invention proposes a hybrid battery pack control method, which is applied to an electric vehicle. The electric vehicle includes a hybrid battery pack, and the hybrid battery pack includes multiple battery packs. The type of at least one battery pack in the multiple battery packs is different from that of the other battery packs. Figure 1 In one embodiment of the present invention, a hybrid battery pack control method includes:

[0064] Step S100: obtaining battery pack parameters of multiple battery packs and / or operating parameters of an electric vehicle;

[0065] Step S200: Determine the target operating mode of the mixed battery pack according to the operating parameters and / or multiple battery parameters, and control the corresponding types of battery packs in the multiple battery packs to form corresponding charging and discharging circuits according to the target operating mode to perform corresponding charging and discharging operations.

[0066] It should be understood that a processor for executing the above-mentioned method steps can be provided in the hybrid battery pack, as well as a switch array electrically connected to multiple battery packs and the processor. Under the control of the processor, the switch array can control different types of battery packs to be in a series or parallel state, and can also open / disconnect the paths between different types of battery packs and the charging and discharging ends of the hybrid battery pack, so that different types of battery packs can be combined into different charging and discharging circuits to enable different types of battery packs to be connected to the discharge end or charging end individually / in parallel / in series for charging and discharging actions, or to realize charging and discharging actions between each other.

[0067] In this embodiment, the battery pack parameters can be the battery pack's power parameters, temperature parameters, capacity parameters, etc., and the electric vehicle's operating condition parameters can be the instructions transmitted by the electric vehicle to the hybrid battery pack, such as acceleration, deceleration, charging, cruise control, etc. R&D personnel can design multiple target operating modes and corresponding battery pack control actions according to the status of multiple battery packs, the type of connected battery packs, and the different usage conditions of the electric vehicle, such as low-temperature operating mode, fast charging operating mode, high-power output operating mode, etc., and all of them are preset in the processor of the hybrid battery pack or in a memory electrically connected to the processor. When the processor enters the corresponding operating mode, it will control the corresponding type (which can be one type or multiple types) of battery packs and the charging end, discharging end or other types of battery packs to form a corresponding charge and discharge circuit to perform the corresponding charge and discharge action according to the specific types of multiple battery packs pre-stored in the processor. This avoids the short-board effect that occurs in traditional mixed battery packs, where different types of battery packs are always connected in series or parallel. In this way, during the actual use of mixed battery packs, the corresponding type of battery pack can be controlled to form the corresponding charge and discharge circuit and perform the corresponding charge and discharge actions based on the actual battery pack type and parameters and the operating conditions of the electric vehicle. Compared with the traditional charging and discharging of multiple battery packs connected in series and parallel, this avoids the short-board effect caused by battery differences and effectively improves the performance of the mixed battery pack.

[0068] In the solution of the present invention, the battery pack parameters of the multiple battery packs and / or the operating parameters of the electric vehicle are first obtained, and then the target operating mode of the mixed battery pack is determined based on the operating parameters and / or the multiple battery parameters, and the corresponding types of battery packs in the multiple battery packs are controlled to form corresponding charge and discharge circuits according to the target operating mode to perform corresponding charge and discharge operations. In this way, during the actual use of mixed battery packs, the corresponding types of battery packs can be controlled to form corresponding charge and discharge circuits and perform corresponding charge and discharge operations based on the actual battery pack type and parameters and the operating status of the electric vehicle. Compared with the traditional method of connecting multiple battery packs in series and parallel to perform charge and discharge operations, this avoids the short board effect caused by battery differences and effectively improves the performance of the mixed battery pack.

[0069] It should be understood that in the actual use scenarios of electric vehicles, the outdoor temperature may be too low. At this time, if the battery pack is mixed in series with battery packs with poor low-temperature charging and discharging performance, it will affect the overall charging and discharging performance of the mixed battery pack.

[0070] refer to Figure 2 ,In one embodiment of the present invention, the hybrid battery pack further comprises a heating device and a charging terminal, and the battery pack parameters include battery pack temperature parameters;

[0071] Step S200 is specifically as follows:

[0072] Step S210: Determine that the electric vehicle is in a charging state based on the operating parameters of the electric vehicle and / or the temperature parameters of multiple battery packs, and when the temperatures of the current multiple battery packs are lower than a preset low temperature, control the mixed battery packs to enter a low-temperature charging mode. In the low-temperature charging mode, control the battery packs of a type that matches the low-temperature charging mode to be connected to the charging end for charging; and control the heating device to be connected to the charging end to enable the heating device to work.

[0073] In this embodiment, the charging terminal can be used to connect to a charging pile or an external power supply to access the charging voltage. Optionally, the BMS mode inside each battery pack generally has a temperature detection mode, which can be used to detect the temperature of the battery cells therein to obtain the battery pack temperature parameters, and the battery pack temperature parameters are transmitted in the form of digital signals, such as SPI signals, I 2 C signal, etc., is uploaded to the processor of the hybrid battery pack. Optionally, the hybrid battery pack may also be provided with multiple temperature detection components electrically connected to the processor, such as a thermistor temperature detection circuit, an infrared sensor, a thermocouple sensor, etc. The multiple temperature detection components detect the temperatures of the multiple battery packs one by one and output the detection results, i.e., the battery pack temperature parameters, to the processor in the form of digital signals or analog signals, so that the processor can determine the current temperatures of the multiple battery packs.

[0074] In this embodiment, the electric vehicle's vehicle controller can output corresponding electric vehicle operating parameters to the hybrid battery pack's processor, allowing the processor to determine whether the electric vehicle is currently in a charging or discharging state. Furthermore, the hybrid battery pack can also determine whether the electric vehicle or hybrid battery pack is currently in a charging state when it detects that a charging voltage is connected to its charging terminal.

[0075] In this embodiment, the heating device can be implemented by a heating film, an infrared heating device, etc.

[0076] In this embodiment, battery packs that match the low-temperature charging mode are generally those with better charge and discharge performance in low-temperature environments, such as ternary NCM battery packs. When the processor determines, based on multiple battery pack temperature parameters, that the current temperature of the multiple battery packs is below a preset low-temperature temperature and that the electric vehicle or hybrid battery pack is charging, it enters the low-temperature charging mode and controls the switch array in the above-described embodiment to open a path between the battery packs with better low-temperature charging performance and the charging terminal, thereby connecting the battery packs that match the low-temperature charging mode to the charging terminal and charging. Simultaneously, the processor also controls the switch array to open a path between the charging terminal and the heating device, powering the heating device and enabling the heating device to operate.

[0077] For example, a hybrid battery pack is provided with two types of battery packs, a ternary NCM battery pack and a lithium iron phosphate LFP battery pack, as well as a heating film. The ternary NCM battery pack has better low-temperature charging and discharging performance. At this time, the charging terminal is connected to the charging pile to start charging the hybrid battery pack and the ambient temperature is low. When the processor confirms that the temperature of multiple battery packs is lower than the preset low temperature, it can first control the switch array to work to conduct the path between the ternary NCM battery pack and the charging terminal, so that the charging pile can charge the ternary NCM battery pack alone first. At the same time, the switch array action is also controlled to conduct the path between the charging terminal and the heating film, that is, the path between the charging pile and the heating film, to power the heating film so that the temperature of the heating film increases the temperature of the lithium iron phosphate LFP battery pack, thereby improving the low-temperature charging capability of the hybrid battery pack. Among them, the preset low temperature can be obtained by the R&D personnel based on multiple tests during the R&D period and pre-stored in the processor of the hybrid battery pack.

[0078] Understandably, the reference Figure 3 In another embodiment, after the step of controlling the heating device to connect to the corresponding battery pack so that the heating device works, the method further includes:

[0079] Step S220: When it is determined according to the temperature parameters of the multiple battery packs that the temperatures of the current multiple battery packs reach a preset normal temperature, the remaining one or more battery packs are controlled to be connected to the charging terminal for charging.

[0080] In this embodiment, when the processor determines that the temperatures of multiple battery packs have reached the preset normal temperature based on the above-mentioned multiple battery pack temperature parameters, or when the processor confirms that the temperatures of the remaining battery packs that are not being charged (referring to the battery packs among the multiple battery packs except for the battery packs with better low-temperature charging performance) have reached the preset normal temperature, it can be confirmed that all batteries can be charged at present, and the switch array can be controlled to start operating to conduct the path between the remaining one or more battery packs and the charging end, so as to control the remaining one or more battery packs to be connected to the charging end for charging.

[0081] Optionally, in another embodiment, if the number of battery pack types in the mixed battery pack is greater than two types, then the preset normal temperature can also be pre-stored with multiple temperature gears to adapt to the temperature gears at which different types of battery packs can be charged normally, and the temperature gears of the corresponding battery packs can be pre-set.

[0082] To illustrate this using the above example, when the processor determines that the temperature of a lithium iron phosphate (LFP) battery pack has reached a preset low temperature, it deems the current LFP battery pack to have good charging performance and controls the switch array to open the path between the LFP battery pack and the charging port, thereby charging all battery packs. In this way, in actual applications, if the ambient temperature is low, resulting in low temperatures for multiple battery packs, the battery packs with good low-temperature charging performance are charged first. Simultaneously, the power supply connected to the charging port, such as a charging station, is configured to power the heating device, thereby operating the heating device and raising the temperature of the battery packs with poor low-temperature charging performance. When the temperatures of multiple battery packs reach the preset low temperature, the paths between all battery packs and the charging port are opened, ensuring that the different battery packs in the hybrid battery pack maintain good charging performance at low temperatures, effectively improving the performance of the hybrid battery pack.

[0083] refer to Figure 4 ,In one embodiment of the present invention, the hybrid battery pack further includes a heating device and a discharge terminal, and the battery pack parameters include battery pack temperature parameters;

[0084] Step S200 is specifically as follows:

[0085] Step S230: Determine that the electric vehicle is in a driving state based on the operating parameters of the electric vehicle and / or the temperature parameters of multiple battery packs, and when the temperatures of the current multiple battery packs are lower than a preset low temperature, control the mixed battery pack to enter a low-temperature discharge mode. In the low-temperature discharge mode, control the battery pack of a type that matches the low-temperature discharge mode to be connected to the discharge end to discharge the electric vehicle; and control the heating device to be connected to the corresponding battery pack to enable the heating device to work.

[0086] In this embodiment, the method of obtaining multiple battery pack temperature parameters can be consistent with the process of the above embodiment. When driving is required, the vehicle controller of the electric vehicle can output the corresponding operating parameters of the electric vehicle so that the processor in the hybrid battery pack can determine that the electric vehicle is currently in a driving state.

[0087] In this embodiment, the heating device can be implemented by a heating film, an infrared heating device, etc.

[0088] It should be understood that a hybrid battery pack may be provided with a main power battery pack and a functional battery pack, such as a lithium iron phosphate LFP battery pack (main power battery pack) with good cycle performance and a ternary NCM battery pack (functional battery pack) with good low-temperature charge and discharge performance. The ternary NCM battery pack meets the type requirements of the low-temperature discharge mode but has poor cycle performance. The lithium iron phosphate LFP battery pack generally has poor charge and discharge performance at low temperatures but good cycle performance. Therefore, when the processor determines based on multiple battery pack temperature parameters that the current temperature of multiple battery packs is lower than the preset low temperature and the electric vehicle or hybrid battery pack is in a charging state, it will enter the low-temperature discharge mode and control the switch array action in the above embodiment to conduct the path between the battery pack with better low-temperature discharge performance and the discharge end among the multiple battery packs, so that the drive components of the electric vehicle can be powered normally under low temperature conditions. At the same time, the switch array action will also be controlled to conduct the path between the battery pack with better low-temperature discharge performance and the heating device to control the heating device to connect to the corresponding battery pack to enable the heating device to work.

[0089] For example, a hybrid battery pack is provided with two types of battery packs, a ternary NCM battery pack and a lithium iron phosphate LFP battery pack, and a heating film. The ternary NCM battery pack has better low-temperature charge and discharge performance. When the temperature of multiple battery packs is lower than the preset low temperature and the electric vehicle is in a driving state, that is, when the electric vehicle is driving in a low-temperature environment. The processor can first control the action of the switch array to conduct the path between the ternary NCM battery pack and the discharge end, so that the ternary NCM battery pack can discharge the driving components of the electric vehicle alone. At the same time, the processor will control the action of the switch array to conduct the path between the ternary NCM battery pack and the heating film to power the heating film so that the temperature of the heating film increases to increase the temperature of multiple battery packs in the hybrid battery pack. Among them, the preset low temperature can be obtained by the R&D personnel based on multiple tests during the R&D period and pre-stored in the processor of the hybrid battery pack.

[0090] Understandably, the reference Figure 5 In another embodiment, after the step of controlling the heating device to connect to the corresponding battery pack so that the heating device works, the method further includes:

[0091] Step S240: When it is determined based on multiple battery pack temperature parameters that the temperatures of the current multiple battery packs reach a preset normal temperature, the path between the battery pack of the type matching the low-temperature discharge mode and the discharge end is disconnected, and the remaining one or more battery packs are controlled to be connected to the discharge end to discharge the electric vehicle.

[0092] In this embodiment, the number of remaining battery packs can be one or more. When the processor determines that the temperatures of the multiple battery packs have reached the preset normal temperature based on the above-mentioned multiple battery pack temperature parameters, or when the processor confirms that the temperature of the remaining main power battery packs in the above-mentioned embodiment that are not charged has reached the preset normal temperature. The battery packs with good low-temperature charging and discharging performance but poor cycle capacity stop supplying power to the discharge end, and instead allow the main power battery pack whose temperature has exceeded the preset low temperature to discharge the discharge end alone, so as to improve the discharge cycle life of the entire hybrid battery pack. At the same time, the processor can also control the switch array to maintain the passage between the conductive functional battery and the heating device to ensure that the temperature of the main power battery pack can always exceed the preset low temperature. Among them, the preset normal temperature is obtained by the R&D personnel based on actual tests and pre-stored in the processor.

[0093] In addition, optionally, in another embodiment, if there are more than two types of battery packs in the battery pack, then when the temperature of multiple battery packs reaches a preset normal temperature, only the switch array can be controlled to conduct the path between the battery pack with better cycle discharge performance among the remaining types and the discharge end to discharge the electric vehicle.

[0094] Specifically, using the above-mentioned embodiment as an example, when the processor determines, based on battery pack temperature parameters, that the temperature of a lithium iron phosphate (LFP) battery pack exceeds a preset low temperature, it controls the switch array to initiate operation, disconnecting the path between the ternary NCM battery pack and the discharge terminal and opening the path between the lithium iron phosphate (LFP) battery pack and the discharge terminal, allowing the lithium iron phosphate (LFP) battery pack with better cycle performance to discharge the electric vehicle's drive components independently. Simultaneously, the path between the ternary NCM battery pack and the heating device is maintained, thereby keeping the temperature of the lithium iron phosphate (LFP) battery pack above the preset low temperature. In this way, in actual applications, if the ambient temperature is low and the temperatures of multiple battery packs are low, the battery pack with better low-temperature charge and discharge performance can be used to discharge the electric vehicle independently through the discharge terminal first, ensuring normal driving in low-temperature environments. Simultaneously, the hybrid battery pack also causes the battery pack with better low-temperature discharge performance to power the heating device, activating the heating device to heat the multiple battery packs until the temperature of the battery pack with better cycle performance exceeds the preset low temperature. At this point, the hybrid battery pack switches to using the battery pack with better cycle performance to discharge the electric vehicle independently, effectively extending the cycle life of the hybrid battery pack.

[0095] refer to Figure 6 In one embodiment of the present invention, the operating parameters of the electric vehicle include the target power parameters of the electric vehicle, the battery pack parameters include the power parameters, and the hybrid battery pack further has a discharge terminal. Step S100 is specifically as follows:

[0096] S130, obtaining target power parameters of the electric vehicle and power parameters of multiple battery packs;

[0097] Step S200 is specifically as follows:

[0098] S250. When it is determined according to the target power parameters of the electric vehicle that the target power of the electric vehicle reaches the preset power, and it is determined according to the power parameters of the multiple battery packs that the power difference between the multiple battery packs does not reach the preset power difference, the mixed battery pack is controlled to enter the high-power discharge mode. In the high-power discharge mode, the multiple battery packs are controlled to be connected to the discharge end so that the multiple battery packs discharge the electric vehicle together.

[0099] It's important to understand that in practice, when a driver is driving an electric vehicle, they accelerate by pressing the accelerator / stoker. At this point, the accelerator / stoker outputs a corresponding acceleration signal to the vehicle controller. Based on the acceleration signal, the vehicle controller outputs a corresponding target power parameter to the drive motor, causing the drive motor to operate at a certain power level to increase the vehicle's speed. Similarly, the vehicle controller also outputs the required target power parameter as a digital signal to the hybrid battery pack's processor, allowing the processor to determine the power required by the electric vehicle at the next moment.

[0100] In this embodiment, the BMS modes within the multiple battery packs detect the current battery cell power levels and output corresponding power parameters in the form of digital signals to the processor, so that the processor can determine the current battery pack voltage.

[0101] In this embodiment, when the processor determines that the target power required by the current electric vehicle at the next moment reaches the preset power, it is considered that the current electric vehicle needs to accelerate. Then, based on multiple power parameters, it is determined that the power difference between multiple battery packs in the mixed battery pack does not reach the preset power difference, that is, when the consistency of the multiple battery packs is good, the processor will control the switch array action so that the multiple battery packs are connected in parallel / series with each other and then discharge the drive components of the electric vehicle together through the discharge end to ensure good acceleration performance of the electric vehicle. In addition, it is understandable that if the power difference between the current multiple battery packs exceeds the preset power difference, the multiple battery packs can be balanced to ensure their consistency. Among them, the preset power and the preset power difference are obtained by the R&D personnel through multiple experiments during the R&D period and pre-stored in the processor.

[0102] Understandably, the reference Figure 7In another embodiment, step S200 further includes:

[0103] Step S260: When it is determined based on the target power parameters of the electric vehicle that the target power of the electric vehicle does not reach the preset power, the hybrid battery pack is controlled to enter the normal discharge mode. In the normal discharge mode, the battery pack of the type matching the normal discharge mode is controlled to be connected to the discharge end to discharge the electric vehicle.

[0104] In this embodiment, the battery pack that matches the normal discharge mode is generally a main power battery pack with good cycle performance, such as a lithium iron phosphate LFP battery pack.

[0105] In this embodiment, when the processor determines, based on the target power parameters in the above embodiment, that the target power of the electric vehicle at the next moment is lower than the preset power, it enters the normal discharge mode. It should be understood that when entering the normal discharge mode, the processor controls the switch array to conduct the path between the main power battery pack and the discharge terminal, so that the main power battery pack alone drives the electric vehicle through the discharge terminal, eliminating the need to discharge the main power battery pack and the functional battery pack together, thereby improving the cycle life of the hybrid battery pack.

[0106] Specifically, a hybrid battery pack is provided with two battery packs, a ternary NCM battery pack and a lithium iron phosphate LFP battery pack, as an example for explanation. It can be seen from the above embodiment that the lithium iron phosphate LFP battery pack has better cycle performance. When the processor confirms that the current target power of the electric vehicle has not reached the preset power, it controls the hybrid battery pack to enter the normal discharge mode to only conduct the path between the lithium iron phosphate LFP battery pack and the discharge end. In this way, when the electric vehicle does not need high power output, only the battery pack with better cycle performance can be controlled to discharge the electric vehicle separately. Compared with the traditional hybrid battery pack, when high power output is not required, the functional battery pack with lower cycle performance will not be allowed to work, nor will the functional battery pack with lower cycle performance affect the cycle work of the main power battery pack, thereby effectively improving the cycle performance of the hybrid battery pack as a whole and extending the service life of the hybrid battery pack.

[0107] In addition, in another embodiment, the driver can also control the touch screen on the electric vehicle or operate an external terminal connected to the electric vehicle to make the vehicle controller output a long-range instruction or a short-range instruction to the processor of the hybrid battery pack based on the actual required driving mileage and the power and mileage of each battery mode fed back by the hybrid battery pack. When the processor receives a short-range instruction, it will only open the path between the battery pack with better cycle performance and the discharge end, thereby improving the cycle life of the entire battery pack. When the processor receives a long-range instruction, it will control the switch array to open the paths between multiple battery packs with a power difference within a preset power difference range and the discharge end, so that multiple battery packs can discharge the electric vehicle in parallel to meet the long-range requirement.

[0108] It should be understood that sometimes users may be short on time and have a long driving distance to cover, so they generally do not fully charge the battery pack. However, when charging a traditional hybrid battery pack, the multiple battery packs of different systems are electrically connected together, so the charging performance of the hybrid battery pack will be affected by the battery pack with the worst charging performance, resulting in slow charging and difficulty in meeting customer needs.

[0109] For this purpose, refer to Figure 8 In one embodiment of the present invention, the hybrid battery pack further includes a charging terminal, and the operating condition parameters further include charging instructions. Step S100 is specifically as follows:

[0110] S140, obtaining a charging instruction for the electric vehicle;

[0111] Step S200 is specifically as follows:

[0112] Step S270: When it is determined that the charging instruction of the electric vehicle is a fast charging instruction, the mixed battery pack is controlled to enter the fast charging mode. In the fast charging mode, the battery pack of the type that matches the fast charging mode is controlled to be connected to the charging end for charging; and after the charging is completed, the battery pack of the type that matches the fast charging mode is controlled to be connected to the remaining one or more battery packs to charge the remaining battery packs.

[0113] In this embodiment, a hybrid battery pack can be equipped with a functional battery pack with fast charging capabilities as a battery pack type that matches the fast charging mode, such as a ternary NCM battery pack. While the vehicle is charging, the driver can operate the touch screen on the electric vehicle or an external terminal connected to the electric vehicle to cause the vehicle controller to output corresponding charging instructions to the processor of the hybrid battery pack. For example, if the driver feels that the current required range is short and wants to charge quickly, the above operation will cause the vehicle controller to output a fast charging instruction to the processor of the hybrid battery pack.

[0114] When the processor receives a fast charge instruction, it will enter the fast charge mode and control the switch array to conduct the path between the battery pack with better fast charge performance among the multiple battery packs and the charging end, so as to charge the battery pack with better fast charge performance. After charging is completed, the path between the battery pack with better fast charge performance and the remaining battery packs is conducted again to charge the remaining battery packs. It is understandable that the battery packs in the general car cannot be charged and discharged at the same time. Therefore, after the user stops using the charging pile and starts, the battery pack with better fast charge performance can not charge the battery pack that is discharging in the remaining battery packs. When the electric vehicle enters the parking state due to traffic jams, waiting for traffic lights, temporarily entering the service area for a rest, etc. (that is, when the processor determines that no battery pack is outputting discharge current through the discharge end or has not received an output instruction from the electric vehicle), the battery pack with better fast charge performance will be allowed to charge all the remaining battery packs.

[0115] For example, a hybrid battery pack currently includes a main power battery pack with excellent cycling performance and a functional battery pack with excellent fast-charging performance. During the electric vehicle charging process, when the hybrid battery pack receives a fast-charging command, it controls the switch array to open only the path between the functional battery pack and the charging terminal, thereby rapidly charging the functional battery pack. When charging is complete and the electric vehicle starts driving, the processor controls the switch array to disconnect the path between the functional battery pack and the charging terminal and only open the path between the main power battery pack and the discharge terminal to power the electric vehicle. When the processor determines that the electric vehicle is parked, it controls the switch array to disconnect the path between the main power battery pack and the discharge terminal and open the path between the functional battery pack and the main power battery pack, placing them in parallel. This allows the functional battery pack to discharge the main power battery pack, thereby charging the main power battery pack. This configuration allows users to charge their electric vehicle more quickly when a quick recharge is needed and the journey is short, shortening the user's charging wait time.

[0116] In another embodiment, if the hybrid battery pack includes a main power battery pack and a functional battery pack, and the main power battery pack has a high specific energy density and a large capacity, and the functional battery pack has a high specific power density but a small capacity, then when the processor confirms that the electric vehicle has entered the charging state, it will control the switch array to only conduct the path between the main power battery pack and the charging end, and during the non-charging period, use the main power battery pack to charge the functional battery pack with a small capacity, thereby reducing the total charging time.

[0117] In another embodiment, if the current charging station supports high-voltage charging, for example, if the hybrid battery pack contains two 400V battery packs and the charging station supports 800V charging, the driver can use the same triggering method as in the above embodiment to cause the electric vehicle's vehicle controller to output an 800V fast-charge command to the processor. Upon receiving the 800V fast-charge command, the processor controls the switch array to connect the two 400V battery packs in series to the charging terminal, thereby achieving high-voltage fast charging.

[0118] refer to Figure 9 The present invention also proposes a hybrid battery pack for use in electric vehicles, characterized in that the hybrid battery pack includes:

[0119] Multiple battery packs;

[0120] Memory 10;

[0121] A processor 20 having a communication terminal for communicating with the electric vehicle;

[0122] Charging terminal;

[0123] discharge terminal;

[0124] switch array 30;

[0125] A hybrid battery pack control program stored in the memory 10 and executed by the processor 20, wherein the hybrid battery pack control program, when executed by the processor 20, implements any of the hybrid battery pack control methods described above;

[0126] The processor 20 is electrically connected to the multiple battery packs, the switch array 30, and the memory 10 respectively; the switch array 30 is electrically connected to the multiple battery packs, the discharge end, and the charge end respectively.

[0127] In this embodiment, the switch array 30 is composed of multiple switching devices such as relays, MOS tubes, IGBT tubes, etc. Under the control of the processor 20, the switch array 30 can control different types of battery packs to be connected in series or in parallel, and can also open / disconnect the paths between the charging and discharging ends of different types of battery packs and mixed battery packs, thereby enabling different types of battery packs to be combined into different charging and discharging circuits.

[0128] In one embodiment of the present invention, reference Figure 10 The hybrid battery pack further includes a heating device 40 and a switch array 30 .

[0129] In this embodiment, the heating device 40 can be implemented using a heating film, heating wire, or heating sheet. When the battery pack parameters transmitted by the battery pack determine that the temperature of multiple battery packs is too low, and when the electric vehicle is currently charging, the switch array 30 is controlled to operate, connecting the heating device 40 to the charging terminal to activate the heating device 40 and thereby increase the temperature of the multiple battery packs. Similarly, if the electric vehicle is currently discharging, the heating device 40 is connected to a battery pack of a type that matches the low-temperature discharge mode, thereby activating the heating device 40 and thereby increasing the temperature of the multiple battery packs.

[0130] In one embodiment of the present invention, reference Figure 10 The number of battery packs in the hybrid battery pack is two, and the two battery packs are a ternary NCM battery pack and a lithium iron phosphate LFP battery pack.

[0131] In one embodiment of the present invention, the hybrid battery pack further includes: a housing;

[0132] The ternary NCM battery pack is arranged on the inner wall of the shell;

[0133] The lithium iron phosphate (LFP) battery pack is located in the center of the housing.

[0134] In this embodiment, the lithium iron phosphate LFP battery pack with poor low-temperature charge and discharge performance can be placed in the middle position, and the ternary NCM battery pack with better low-temperature charge and discharge performance is arranged around it, so as to keep the lithium iron phosphate LFP battery pack warm and reduce the heat loss of the lithium iron phosphate LFP battery pack.

[0135] In one embodiment of the present invention, reference Figure 10 , the number of charging terminals is multiple, and the multiple charging terminals are electrically connected to the switch array 30;

[0136] The processor 20 is further configured to receive a multi-charge gun instruction from the electric vehicle, and upon receiving the multi-charge gun instruction, control the switch array 30 to operate so as to connect paths between the multiple charging terminals and the multiple battery packs in a one-to-one correspondence.

[0137] In this embodiment, the electric vehicle is equipped with multiple charging ports, each of which is used to electrically connect to the multiple charging terminals of the hybrid battery pack. If the driver desires fast charging, they can trigger the vehicle controller to output a multi-charger charging command to the processor 20 using the triggering method described in the above embodiment. Upon receiving the multi-charger charging command, the processor 20 controls the switch array 30 to connect the multiple charging terminals to the multiple battery packs in a one-to-one manner. This allows the hybrid battery pack to be charged using multiple charging ports, improving charging efficiency.

[0138] It is worth noting that because the hybrid battery pack of the present invention includes all embodiments of the above-mentioned hybrid battery pack control method and / or the hybrid battery pack control method of the above-mentioned variable capacitor, the hybrid battery pack of the present invention has all the beneficial effects of the above-mentioned hybrid battery pack control method and / or the above-mentioned variable capacitor, which will not be repeated here.

[0139] The present invention also provides an electric vehicle, which includes any hybrid battery pack as described above.

[0140] It is worth noting that, because the electric vehicle of the present invention includes all embodiments of the above-mentioned hybrid battery pack, the electric vehicle of the present invention has all the beneficial effects of the above-mentioned hybrid battery pack, which will not be repeated here.

[0141] In this embodiment, the electric vehicle's vehicle controller is connected to the communication port of the processor in the hybrid battery pack to enable data and command interaction between the vehicle controller and the hybrid battery pack, such as receiving acceleration commands from the vehicle controller. The processor in the hybrid battery pack can feed back various battery parameters output by the BMSs in the current multiple battery packs, as well as the switching and conduction status of the switch array in the current hybrid battery pack, to the vehicle controller.

[0142] The above descriptions are merely optional embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present description and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A hybrid battery pack control method, applied to an electric vehicle, wherein the electric vehicle includes a hybrid battery pack, and the hybrid battery pack includes multiple battery packs, characterized in that: The type of at least one battery pack among the plurality of battery packs is different from that of the other battery packs, and the mixed battery pack control method includes: Acquiring battery pack parameters of a plurality of the battery packs and / or operating parameters of the electric vehicle; Determining a target operating mode for the mixed battery pack according to the operating condition parameter and / or the parameters of the plurality of battery packs, and controlling the battery packs of corresponding types among the plurality of battery packs to form corresponding charge and discharge circuits according to the target operating mode to perform corresponding charge and discharge operations; The operating condition parameters of the electric vehicle include target power parameters of the electric vehicle, the battery pack parameters include power parameters, and the hybrid battery pack further has a discharge terminal. The steps of obtaining the battery pack parameters of the plurality of battery packs and / or the operating condition parameters of the electric vehicle are specifically as follows: Obtaining a target power parameter of the electric vehicle and power parameters of the plurality of battery packs; The steps of determining a target operating mode of the mixed battery pack according to the operating condition parameters and / or the multiple battery pack parameters, and controlling the corresponding types of battery packs in the multiple battery packs to form corresponding charge and discharge circuits according to the target operating mode to perform corresponding charge and discharge operations are specifically as follows: When it is determined based on the target power parameters of the electric vehicle that the target power of the electric vehicle reaches the preset power, and it is determined based on the power parameters of the multiple battery packs that the power difference between the multiple battery packs does not reach the preset power difference, the mixed battery pack is controlled to enter the high-power discharge mode. In the high-power discharge mode, the multiple battery packs are controlled to be connected to the discharge end so that the multiple battery packs discharge the electric vehicle together.

2. The hybrid battery pack control method according to claim 1, wherein: The hybrid battery pack further comprises a heating device and a charging terminal, and the battery pack parameters include battery pack temperature parameters; The steps of determining a target operating mode of the mixed battery pack according to the operating condition parameters and / or the multiple battery pack parameters, and controlling the corresponding types of battery packs in the multiple battery packs to form corresponding charge and discharge circuits according to the target operating mode to perform corresponding charge and discharge operations are specifically as follows: According to the operating parameters of the electric vehicle and / or the temperature parameters of the multiple battery packs, it is determined that the electric vehicle is in a charging state, and when the temperatures of the multiple battery packs are currently lower than a preset low temperature, the mixed battery pack is controlled to enter a low-temperature charging mode. In the low-temperature charging mode, the battery pack of a type matching the low-temperature charging mode is controlled to be connected to the charging end for charging; and the heating device is controlled to be connected to the charging end to enable the heating device to work.

3. The hybrid battery pack control method according to claim 2, wherein: After the step of controlling the heating device to connect to the corresponding battery pack so that the heating device works, the step further includes: When it is determined according to the temperature parameters of the battery packs that the temperatures of the current plurality of battery packs reach a preset normal temperature, the remaining one or more battery packs are controlled to be connected to the charging end for charging.

4. The hybrid battery pack control method according to claim 1, wherein: The hybrid battery pack further comprises a heating device and a discharge terminal, and the battery pack parameters include battery pack temperature parameters; The steps of determining a target operating mode of the mixed battery pack according to the operating condition parameters and / or the multiple battery pack parameters, and controlling the corresponding types of battery packs in the multiple battery packs to form corresponding charge and discharge circuits according to the target operating mode to perform corresponding charge and discharge operations are specifically as follows: According to the operating parameters of the electric vehicle and / or the temperature parameters of the multiple battery packs, it is determined that the electric vehicle is in a driving state, and when the temperatures of the multiple battery packs are currently lower than a preset low temperature, the hybrid battery pack is controlled to enter a low-temperature discharge mode. In the low-temperature discharge mode, the battery pack of a type matching the low-temperature discharge mode is controlled to be connected to the discharge end to discharge the electric vehicle; and the heating device is controlled to be connected to the corresponding battery pack to enable the heating device to work.

5. The hybrid battery pack control method according to claim 4, characterized in that: After the step of controlling the heating device to connect to the corresponding battery pack so that the heating device works, the step further includes: When it is determined based on multiple battery pack temperature parameters that the temperatures of the current multiple battery packs reach a preset normal temperature, the path between the battery pack of the type matching the low-temperature discharge mode and the discharge end is disconnected, and the remaining one or more battery packs are controlled to be connected to the discharge end to discharge the electric vehicle.

6. The hybrid battery pack control method according to claim 1, wherein: The step of determining a target operating mode of the mixed battery pack according to the operating condition parameter and / or the multiple battery pack parameters, and controlling the battery packs of corresponding types among the multiple battery packs to form corresponding charge and discharge circuits to perform corresponding charge and discharge operations according to the target operating mode also includes: When it is determined based on the target power parameters of the electric vehicle that the target power of the electric vehicle does not reach the preset power, the hybrid battery pack is controlled to enter the normal discharge mode. In the normal discharge mode, the battery pack of the type matching the normal discharge mode is controlled to be connected to the discharge end to discharge the electric vehicle.

7. The hybrid battery pack control method according to claim 1, wherein: The hybrid battery pack further includes a charging terminal, and the operating condition parameters further include charging instructions. The steps of obtaining the battery pack parameters of the plurality of battery packs and / or the operating condition parameters of the electric vehicle are specifically as follows: Obtaining a charging instruction for the electric vehicle; The steps of determining a target operating mode of the mixed battery pack according to the operating condition parameters and / or the multiple battery pack parameters, and controlling the corresponding types of battery packs in the multiple battery packs to form corresponding charge and discharge circuits according to the target operating mode to perform corresponding charge and discharge operations are specifically as follows: When it is determined that the charging instruction of the electric vehicle is a fast charging instruction, the mixed battery pack is controlled to enter the fast charging mode. In the fast charging mode, the battery pack of the type matching the fast charging mode is controlled to be connected to the charging end for charging; and after charging is completed, the battery pack of the type matching the fast charging mode is controlled to be connected to the remaining one or more battery packs to charge the remaining battery packs.

8. A hybrid battery pack, used in electric vehicles, characterized in that: The hybrid battery pack includes: Multiple battery packs; Memory; a processor having a communication terminal for communicating with the electric vehicle; Charging terminal; discharge terminal; switch array; a hybrid battery pack control program stored in the memory and executed by the processor, wherein the hybrid battery pack control program, when executed by the processor, implements the hybrid battery pack control method according to any one of claims 1 to 7; The processor is electrically connected to the plurality of battery packs, the switch array, and the memory respectively; and the switch array is electrically connected to the plurality of battery packs, the discharge end, and the charge end respectively.

9. The hybrid battery pack according to claim 8, wherein: The hybrid battery pack further includes: A heating device is electrically connected to the switch array.

10. The hybrid battery pack according to claim 8, wherein: There are multiple charging terminals, and each of the charging terminals is electrically connected to the switch array; The processor is further configured to receive a multi-gun charging instruction from the electric vehicle, and upon receiving the multi-gun charging instruction, control the switch array to operate so as to connect paths between the plurality of charging terminals and the plurality of battery packs in a one-to-one correspondence.

11. The hybrid battery pack according to claim 8, wherein: The number of the battery packs is two, and the two battery packs are a ternary NCM battery pack and a lithium iron phosphate LFP battery pack.

12. The hybrid battery pack according to claim 11, wherein: The hybrid battery pack further includes: a housing; The ternary NCM battery pack is arranged on the inner wall of the shell; The lithium iron phosphate (LFP) battery pack is disposed at the center of the housing.

13. An electric vehicle, characterized in that: Including the hybrid battery pack as described in any one of claims 8-12.

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