Electric drive system, control method, and vehicle

Abstract

The invention provides an electric driving system, a control method and a vehicle. The electric driving system comprises a first driving system and a second driving system, wherein the first driving system is used for driving a first part of wheels of the vehicle; the second driving system is used for driving a second part of wheels of the vehicle; the battery system comprises a plurality of battery modules, and a first part of the battery modules of the battery system are electrically connected with the first driving system and used for supplying power to the first driving system; a second part battery module of the battery system is electrically connected with the second driving system and is used for supplying power to the second driving system; the first part battery module and the second part battery module are connected in parallel; or, a plurality of battery modules included in the battery system are connected in series, and the power supply voltages of the first part of battery modules and the second part of battery modules are different; and the first part of battery module and the second part of battery module share the same battery module. In this way, power can be dynamically distributed as required.

Description

Technical Field

[0001] The present application relates to the field of new energy vehicles, and more specifically, to an electric drive system, a control method, and a vehicle. Background Art

[0002] In the power system of traditional four-wheel drive electric vehicles, the battery pack is usually designed as a high-voltage unit (such as 800V) as the single power source for the entire vehicle. The battery pack can then distribute power to the front and rear drive systems through the power distribution unit (PDU). However, the front and rear drive systems must passively adapt to the fixed topology of the battery modules in the battery pack and cannot dynamically distribute power according to demand. Summary of the invention

[0003] The purpose of the embodiments of the present application is to provide an electric drive system, a control method and a vehicle for dynamically allocating power according to demand.

[0004] In the first aspect, an embodiment of the present application provides a drive system, including: a first drive system, the first drive system is used to drive a first part of the wheels of a vehicle; a second drive system, the second drive system is used to drive a second part of the wheels of the vehicle; a battery system, the battery system includes a plurality of battery modules, the first part of the battery modules of the battery system is electrically connected to the first drive system, and is used to power the first drive system; the second part of the battery modules of the battery system is electrically connected to the second drive system, and is used to power the second drive system. In this way, the battery system is decoupled into a first part of the battery modules and a second part of the battery modules, so that the first drive system and the second drive system do not need to passively adapt to the fixed topology of the battery modules in the battery system. Subsequently, different drive systems can select different power sources according to different needs. Therefore, the power supply can be dynamically allocated according to demand.

[0005] In addition, the first battery module is connected in parallel with the second battery module. In this way, by adopting this partitioned parallel solution, the two battery modules can independently power their respective drive systems, realize power supply decoupling, and facilitate dynamic allocation of power supply and power output according to demand. Moreover, when one of the battery modules or drive systems fails, the other can continue to work, thereby improving the overall reliability of the system.

[0006] In addition, the battery system includes a plurality of battery modules connected in series, and the supply voltages of the first battery module and the second battery module are different. In this way, the voltage platforms between the first drive system and the second drive system can also be different, so that the drive system on the side that does not have a strong demand for high-power motors can reduce its platform voltage, thereby reducing the use cost of low-power high-voltage loads.

[0007] In addition, the first battery module and the second battery module share a common battery module. This makes it easier to manage multiple battery modules. Moreover, even if a battery module fails, a certain voltage output can be maintained through the shared battery module, reducing the risk of any drive system failing to work due to a single battery module failure.

[0008] Optionally, the electric drive system further includes: a first power distribution unit, the first power distribution unit is connected to the overall positive and negative electrodes of the first battery module through a high-voltage cable, and is connected to the power input interface of the first drive system through another high-voltage cable; a second power distribution unit, the second power distribution unit is connected to the overall positive and negative electrodes of the second battery module through a high-voltage cable, and is connected to the power input interface of the second drive system through another high-voltage cable. In this way, after the battery modules in the battery system are decoupled into the first battery module and the second battery module, each battery module can adaptively distribute power through the corresponding power distribution unit, thereby facilitating the purpose of dynamically distributing power.

[0009] Optionally, the battery system is configured to be disposed in a chassis area between the first drive system and the second drive system. In this case, the second drive system can be directly electrically connected to the second part of the battery module in the battery system, and then the high-voltage power of one drive system does not need to be transmitted to another drive system over a long distance through a high-voltage cable. In this way, compared with the wiring method in the related art, the use length of the high-voltage cable can be shortened, the safety risk is reduced, and the use cost of the high-voltage cable is also reduced.

[0010] Optionally, the battery system is configured such that: the distance between the first battery module's overall positive and negative poles and the first power distribution unit is smaller than the distance between the first battery module's overall positive and negative poles and the second power distribution unit; the distance between the second battery module's overall positive and negative poles and the second power distribution unit is smaller than the distance between the second battery module's overall positive and negative poles and the first power distribution unit. This can further shorten the length of the high-voltage cable.

[0011] Optionally, the first drive system is a rear drive system, and the second drive system is a front drive system, so that power decoupling between the front drive system and the rear drive system can be achieved.

[0012] Optionally, the electric drive system further includes: a third drive system, the third drive system is used to drive a third part of the wheels of the vehicle; a fourth drive system, the fourth drive system is used to drive a fourth part of the wheels of the vehicle; the third part of the battery module of the battery system is electrically connected to the third drive system, and is used to supply power to the third drive system; the fourth part of the battery module of the battery system is electrically connected to the fourth drive system, and is used to supply power to the fourth drive system. In this way, power decoupling between multiple drive systems can be achieved, and power can be dynamically allocated to multiple drive systems.

[0013] Optionally, the first part of battery modules is all battery modules of the battery system, and the second part of battery modules is part of battery modules connected in series in the battery system. In this way, it is convenient to dynamically allocate power according to power demand.

[0014] Optionally, the electric drive system further includes a controller, which is used to: during the discharge process of the battery system, according to the drive power demand, control the first drive system and / or the second drive system to provide drive power to reduce the voltage difference between the first battery module and the second battery module. In this way, by adaptively controlling the drive power of the first drive system and / or the second drive system during the discharge process of the battery system, the voltage inconsistency between the first battery module and the second battery module is improved, thereby improving the vehicle's cruising range.

[0015] Optionally, if the first drive system is a rear drive system and the second drive system is a front drive system, the controller is further configured to: if the driving power requirement is not greater than the first driving power of the first drive system, provide driving power through the first drive system; if the driving power requirement is greater than the first driving power of the first drive system, provide driving power through the first drive system and the second drive system. In this way, the driving power requirement and the voltage inconsistency can be taken into account, so that the voltage difference between the first battery module and the second battery module can be reduced on the basis of meeting the driving power requirement.

[0016] Optionally, the controller is further used to: determine a first SOC according to a first current flowing through the first battery module; determine a second SOC according to a second current flowing through the second battery module and the first current; determine a first allowable current flowing through the first drive system according to the smaller of the first SOC and the second SOC; and determine a first drive power of the first drive system according to the first allowable current and the voltage of the first drive system. In this way, the risk of over-discharge of the second battery module can be reduced, and a more accurate first drive power can be obtained.

[0017] Optionally, if the driving power demand is greater than the first driving power of the first driving system, the controller is further used to: if the driving power demand is greater than the first driving power of the first driving system, determine the remaining driving power demand according to the driving power demand and the first driving power; determine the current supplied to the second driving system according to the remaining driving power demand and the voltage of the second driving system; determine the allowable current supplied to the second driving system according to the maximum allowable output current of the second driving system and the first current flowing through the first driving system; determine the smaller of the current supplied to the second driving system and the allowable current as the target allowable current supplied to the second driving system; and control the second driving system to provide driving power according to the target allowable current. In this way, when the first driving power of the first driving system is insufficient to meet the driving power demand, the second driving system is controlled to provide driving power to meet the driving power demand. In this way, the voltage inconsistency between the first part of the battery module and the second part of the battery module can be improved while meeting the driving power demand. In addition, since the target allowable current is the smaller of the current determined to be supplied to the second driving system and the allowable current, the risk of over-discharge of the second part of the battery module can be reduced after the target allowable current is supplied to the second driving system.

[0018] Optionally, the electric drive system further includes a controller, which is used to: during the recharging process of the battery system, according to the recharging power requirement of the battery system, control the braking power of the first drive system and / or the second drive system to reduce the voltage difference between the first battery module and the second battery module. In this way, by adaptively controlling the braking power of the first drive system and / or the second drive system during the recharging process of the battery system, the voltage inconsistency between the first battery module and the second battery module is improved, thereby improving the vehicle's cruising range.

[0019] Optionally, if the first drive system is a rear-wheel drive system and the second drive system is a front-wheel drive system, the controller is further used to: determine the first SOC corresponding to the first part of the battery module and the second SOC corresponding to the second part of the battery module; if the second SOC is less than the first SOC, then when the recharging power demand is not greater than the second recharging allowable power corresponding to the second drive system, increase the braking power of the second drive system; if the second SOC is less than the first SOC, then when the recharging power demand is greater than the second recharging allowable power corresponding to the second drive system, increase the braking power of the first drive system; if the second SOC is not less than the first SOC, increase the braking power of the first drive system. In this way, the first drive system or the second drive system is adaptively controlled to recharge based on the size relationship between the first SOC and the second SOC, which improves the accuracy of control to a certain extent. In addition, during the recharging process, the recharging efficiency of the first drive system and the second drive system can be taken into account, which also improves the vehicle's cruising range to a certain extent.

[0020] Optionally, the controller is further used to: after controlling the first drive system to provide braking power, determine the first recharge allowable current corresponding to the first drive system according to the larger of the first SOC and the second SOC; determine the second recharge allowable current corresponding to the second drive system according to the second SOC; if the current difference between the second recharge allowable current and the first recharge allowable current is greater than 0, control the braking power of the second drive system according to the current difference. In this way, by continuing to recharge through the current difference, the second recharge allowable current can be made not greater than the first recharge allowable current, thereby reducing the risk of overcharging the second part of the battery module.

[0021] Optionally, the controller is further used to: after controlling the first drive system to provide braking power, if the current recharge power demand is greater than the first recharge allowable power corresponding to the first drive system, then when the current difference between the second recharge allowable current and the first recharge allowable current is greater than 0, control the braking power of the second drive system according to the current difference; if the current recharge power demand is not greater than the first recharge allowable power, redetermine the first SOC and the second SOC to re-control the braking power of the first drive system and / or the second drive system. In this way, the second recharge allowable current can be made not greater than the first recharge allowable current, thereby reducing the risk of overcharging the second part of the battery module.

[0022] In a second aspect, an embodiment of the present application provides a control method for an electric drive system, comprising: during the discharge process of the battery system, according to the driving power requirement, controlling the first drive system and / or the second drive system to provide driving power to reduce the voltage difference between the first part of the battery module and the second part of the battery module; and / or, during the recharging process of the battery system, according to the recharging power requirement of the battery system, controlling the braking power of the first drive system and / or the second drive system to reduce the voltage difference between the first part of the battery module and the second part of the battery module.

[0023] Optionally, if the first drive system is a rear-wheel drive system and the second drive system is a front-wheel drive system, if the driving power demand is not greater than the first driving power of the first drive system, the driving power is provided by the first drive system; if the driving power demand is greater than the first driving power of the first drive system, the driving power is provided by the first drive system and the second drive system.

[0024] Optionally, a first SOC is determined based on a first current flowing through the first part of the battery module; a second SOC is determined based on a second current flowing through the second part of the battery module and the first current; a first allowable current flowing through the first drive system is determined based on the smaller of the first SOC and the second SOC; and a first drive power of the first drive system is determined based on the first allowable current and the voltage of the first drive system.

[0025] Optionally, if the driving power demand is greater than the first driving power of the first driving system, then if the driving power demand is greater than the first driving power of the first driving system, determine the remaining driving power demand according to the driving power demand and the first driving power; determine the current supplied to the second driving system according to the remaining driving power demand and the voltage of the second driving system; determine the allowable current supplied to the second driving system according to the maximum allowable output current of the second driving system and the first current flowing through the first driving system; determine the smaller of the current supplied to the second driving system and the allowable current as the target allowable current supplied to the second driving system; and control the second driving system to provide driving power according to the target allowable current.

[0026] Optionally, if the first drive system is a rear-wheel drive system and the second drive system is a front-wheel drive system, the first SOC corresponding to the first part of the battery module and the second SOC corresponding to the second part of the battery module are determined; if the second SOC is less than the first SOC, when the recharging power demand is not greater than the second recharging allowable power corresponding to the second drive system, the braking power of the second drive system is increased; if the second SOC is less than the first SOC, when the recharging power demand is greater than the second recharging allowable power corresponding to the second drive system, the braking power of the first drive system is increased; if the second SOC is not less than the first SOC, the braking power of the first drive system is increased.

[0027] Optionally, after controlling the first drive system to provide braking power, a first recharge allowable current corresponding to the first drive system is determined according to the larger of the first SOC and the second SOC; a second recharge allowable current corresponding to the second drive system is determined according to the second SOC; if the current difference between the second recharge allowable current and the first recharge allowable current is greater than 0, the braking power of the second drive system is controlled according to the current difference.

[0028] Optionally, after controlling the first drive system to provide braking power, if the current recharging power demand is greater than the first recharging allowable power corresponding to the first drive system, then when the current difference between the second recharging allowable current and the first recharging allowable current is greater than 0, the braking power of the second drive system is controlled according to the current difference; if the current recharging power demand is not greater than the first recharging allowable power, the first SOC and the second SOC are redetermined to re-control the braking power of the first drive system and / or the second drive system.

[0029] In a third aspect, an embodiment of the present application provides a vehicle, comprising: an electric drive system as provided in the first aspect.

[0030] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or be understood by practicing the embodiments of the present application. The purpose and other advantages of the present application can be realized and obtained by the structures specifically pointed out in the written description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 It is a structural diagram of the electric drive system in existing new energy vehicles; Figure 2 A structural diagram of a first electric drive system provided in an embodiment of the present application; Figure 3 A structural diagram of a second electric drive system provided in an embodiment of the present application; Figure 4 A structural diagram of a third electric drive system provided in an embodiment of the present application; Figure 5 A flowchart of a control method performed by a controller provided in an embodiment of the present application; Figure 6 A flow chart of a control method performed by a controller during a discharge process provided in an embodiment of the present application; Figure 7 A flowchart of a control method executed by a controller during a recharging process provided in an embodiment of the present application. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0034] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0035] It should be noted that the embodiments in this application or the technical features in the embodiments may be combined if there is no conflict.

[0036] In the related art, there is a problem that power cannot be dynamically allocated according to demand. Figure 1 The electric drive system of an existing new energy vehicle shown in the figure includes a front drive system, a rear drive system and a battery pack. The battery pack is designed as a high-voltage unit, which can distribute power to the rear drive system through a power distribution unit and to the front drive system through another power distribution unit. Furthermore, the battery pack includes a plurality of battery modules, and the number of battery modules can be set according to actual needs. Figure 1 In the embodiment, there are four battery modules connected in series, namely, battery module 1, battery module 2, battery module 3 and battery module 4. The four battery modules have the following characteristics: Figure 1 The fixed topology shown. However, the front and rear drive systems must passively adapt to the fixed topology of the battery modules in the battery pack (for example, the front and rear drive systems must be powered by the positive electrode of battery module 1 and the negative electrode of battery module 4 in the battery pack), making it impossible to dynamically allocate power as needed. For example, if the battery pack can provide a voltage of 800V, the voltage allocated to the rear drive system and the front drive system is 800V. In this way, power cannot be dynamically allocated as needed (for example, 800V is allocated to the rear drive system and 400V is allocated to the front drive system).

[0037] Therefore, in order to solve the above problems, the present application provides an electric drive system. Specifically, the electric drive system includes a first drive system, a second drive system and a battery system. The first drive system is used to drive a first part of the wheels of the vehicle; the second drive system is used to drive a second part of the wheels of the vehicle; the battery system includes a plurality of battery modules, the first part of the battery modules of the battery system are electrically connected to the first drive system, and are used to supply power to the first drive system; the second part of the battery modules of the battery system are electrically connected to the second drive system, and are used to supply power to the second drive system.

[0038] The first drive system may be, for example, a front drive system or a rear drive system, wherein when it is a front drive system, the second drive system is the corresponding rear drive system; when it is a rear drive system, the second drive system is the corresponding front drive system.

[0039] The first part of wheels may be one wheel or multiple wheels; the second part of wheels may be one wheel or multiple wheels, which is not limited here. For example, the first part of wheels and the second part of wheels may be the front wheel and the rear wheel, respectively. Alternatively, the first part of wheels is the left front wheel, and the second part of wheels is the right front wheel.

[0040] Furthermore, the first drive system includes a first motor, and the second drive system includes a second motor, and the first motor and the second motor are respectively used to drive the corresponding wheels to rotate. If the first drive system is a front-wheel drive system, the first motor can be used to drive the front wheels of the vehicle to rotate, and the second motor can be used to drive the rear wheels of the vehicle to rotate; if the first drive system is a rear-wheel drive system, the first motor can be used to drive the rear wheels to rotate, and the second motor can be used to drive the front wheels of the vehicle to rotate.

[0041] The multiple battery modules included in the above battery system can be connected in series or in parallel, which is not limited here.

[0042] See also Figure 2 , which shows an electric drive system provided by an embodiment of the present application. It should be understood that in order to Figure 1 The contrast effect, Figure 2 The battery system also includes four battery modules connected in series, namely battery module 1, battery module 2, battery module 3 and battery module 4. However, in fact, the number of battery modules can be adaptively set according to actual needs.

[0043] like Figure 2 As shown, four battery modules connected in series constitute the first battery module, the positive terminal of battery module 1 serves as the overall positive terminal of the first battery module, and the negative terminal of battery module 4 serves as the overall negative terminal of the first battery module, and both are electrically connected to the first drive system. The positive terminal of battery module 2 serves as the overall positive terminal of the second battery module, and the negative terminal of battery module 3 serves as the overall negative terminal of the second battery module, and both are electrically connected to the second drive system.

[0044] It should be noted that in other application scenarios, the above-mentioned battery system may also be a structure including battery modules that are not all connected in series. For example, the battery system includes a first part of battery modules and a second part of battery modules, the first part of the battery modules includes a plurality of battery modules connected in series, and the second part of the battery modules also includes a plurality of battery modules connected in series. The first part of the battery modules and the second part of the battery modules are not connected in series. For example, the first part of the battery modules are connected in parallel with the second part of the batteries. In this way, the overall positive and negative electrodes of the first part of the battery modules can also be electrically connected to the first drive system respectively, and the overall positive and negative electrodes of the second part of the battery modules can be electrically connected to the second drive system.

[0045] It should be understood that, in addition to driving the wheels, the first drive system and the second drive system can also provide power to other components of the vehicle. For example, the first drive system and / or the second drive system can provide power to the air conditioner.

[0046] In this implementation, the battery system is decoupled into a first battery module and a second battery module, so that the first drive system and the second drive system do not need to passively adapt to the fixed topology of the battery module in the battery system. Subsequently, different drive systems can select different power supplies according to different needs (for example, the first drive system selects an 800V power supply and the second drive system selects a 400V power supply). Therefore, this implementation can dynamically allocate power according to demand. In addition, when a part of the battery modules has a power supply abnormality, another part of the battery modules can also supply power normally to enable the corresponding drive system of the vehicle to work normally.

[0047] In some optional implementations, the first battery module is connected in parallel with the second battery module. That is, the first battery module and the second battery module are connected to the first drive system and the second drive system respectively, and the two battery modules are connected in parallel. With this partitioned parallel solution, the two battery modules can independently power their respective drive systems, realize power supply decoupling, and facilitate dynamic allocation of power supply and power output according to demand. Moreover, when one part of the battery module or drive system fails, the other part can continue to work, thereby improving the overall reliability of the system.

[0048] Furthermore, the inventors have also found in the long-term practice that in the relevant technology, in order to facilitate the management of the power of the whole vehicle, the front-drive motor, the rear-drive motor and the related high-voltage loads are often operated on the same voltage platform. In order to improve the power conversion efficiency of the vehicle, the front-drive motor or the rear-drive motor is usually a high-power motor, which requires a higher platform voltage (for example, 800V), which in turn leads to the need for small-power high-voltage loads such as DCDC (DC-DC Converter, DCDC for short), high-voltage air conditioners, PTC (Positive Temperature Coefficient thermistor, PTC for short) to use a higher platform voltage. Therefore, the cost of using this part of the small-power high-voltage load is relatively high.

[0049] Therefore, in some other optional implementations, the present application sets the battery system to include multiple battery modules connected in series, and the first battery module and the second battery module have different power supply voltages. For example, the first battery module provides a power supply voltage of 800V to the first drive system, and the second battery module provides a power supply voltage of 400V to the second drive system.

[0050] In this way, the voltage platforms between the first drive system and the second drive system can be different, so that the drive system on the side that does not have a strong demand for high-power motors can lower its platform voltage, thereby reducing the use cost of small-power high-voltage loads.

[0051] For easier understanding, please continue to refer to Figure 3 , which shows a structural diagram of a second electric drive system provided in an embodiment of the present application. Figure 3 The battery system includes five battery modules connected in series, wherein battery modules 1-5 constitute the first battery module, and battery module 2 and battery module 3 constitute the second battery module. At this time, the input voltage of the second drive system is 2 / 5 of the input voltage of the first drive system.

[0052] Please continue reading Figure 4 , which shows the structure of the third electric drive system provided by the embodiment of the present application. Figure 4 As shown, the battery system includes 6 battery modules connected in series, wherein battery modules 1-6 constitute the first part of the battery modules; battery modules 2-5 constitute the second part of the battery modules, and at this time the input voltage of the second drive system is 4 / 6 of the input voltage of the first drive system.

[0053] Therefore, the above-mentioned electric drive system can make the first motor, the second motor and related high-voltage loads operate on different voltage platforms, so that some small-power high-voltage loads can operate on a relatively low voltage platform, thereby reducing the use cost of small-power high-voltage loads and reducing the use cost of the entire vehicle to a certain extent.

[0054] Furthermore, since the platform voltages between the first drive system and the second drive system can be different, electrical decoupling of the first drive system and the second drive system is achieved, and then one of the drive systems can be used to drive the vehicle under extreme working conditions (for example, driving in muddy, sandy, snowy, etc.).

[0055] In addition, the battery system is composed of multiple battery modules connected in series, and the voltage can be adjusted according to demand, thereby meeting the voltage requirements of the drive system.

[0056] Alternatively, when the battery system includes a plurality of battery modules connected in series, the supply voltages of the first portion of battery modules and the second portion of battery modules may also be the same.

[0057] Furthermore, when a plurality of battery modules of the battery system are connected in series, the first battery modules and the second battery modules share common battery modules. Figure 2In the embodiment, there are common battery modules 2 and 3. In this way, it is convenient to manage multiple battery modules in a coordinated manner (for example, to manage the voltage and power of multiple battery modules in a coordinated manner). In addition, even if a battery module fails, a certain voltage output can be maintained through the common battery module, reducing the risk of any drive system failing to work due to a single battery module failure.

[0058] Alternatively, to achieve different supply voltages for the first battery module and the second battery module, the first battery module and the second battery module may not share a common battery module. Figure 4 In the embodiment, the first part of the battery modules includes battery modules 1-4, and the second part of the battery modules includes battery modules 5-6.

[0059] Furthermore, the first part of the battery modules is all the battery modules of the battery system, and the second part of the battery modules is part of the battery modules connected in series in the battery system. In this way, for example, the first part of the battery modules can be used in a drive system with a relatively large power demand, and the second part of the battery modules can be used in a drive system with a relatively small power demand. Then, it is also convenient to dynamically allocate power according to power demand.

[0060] In some optional implementations, the system also includes: a first power distribution unit, which is connected to the overall positive and negative poles of the first part of the battery module through a high-voltage cable, and is connected to the power input interface of the first drive system through another high-voltage cable; a second power distribution unit, which is connected to the overall positive and negative poles of the second part of the battery module through a high-voltage cable, and is connected to the power input interface of the second drive system through another high-voltage cable.

[0061] For example, in Figure 2 In the embodiment, the positive terminal of the first power distribution unit (PDU1) is connected to the positive electrode of the battery module 1 through a high-voltage cable, and the negative terminal of PDU1 is connected to the negative electrode of the battery module 4 through a high-voltage cable. In addition, PDU1 is connected to the power input interface of the first drive system through another high-voltage cable; the positive terminal of the second power distribution unit (PDU2) is connected to the positive electrode of the battery module 2 through a high-voltage cable, and the negative terminal of PDU2 is connected to the negative electrode of the battery module 3 through a high-voltage cable. In addition, PDU2 is connected to the power input interface of the second drive system through another high-voltage cable.

[0062] In this implementation, after the battery modules in the battery system are decoupled into a first battery module and a second battery module, each battery module can adaptively distribute power through a corresponding power distribution unit, thereby facilitating the purpose of dynamically distributing power.

[0063] In addition, in related technologies, as the demand for charging speed and driving range of new energy vehicles continues to increase, more and more vehicles with high voltage platforms have appeared on the market. As the voltage platform increases, the demand for safety protection of high-voltage cables that transmit high-voltage electricity also increases.

[0064] Furthermore, the increased safety protection requirements for high-voltage cables have a greater impact on new energy vehicles including four-wheel drive systems. The specific reason is that this type of new energy vehicle includes a front-wheel drive system and a rear-wheel drive system. High-voltage power is usually transmitted from the front-wheel drive system to the rear-wheel drive system, or from the rear-wheel drive system to the front-wheel drive system. Therefore, in this type of new energy vehicle, the safety risk is often increased due to the need to use relatively long high-voltage cables.

[0065] Furthermore, currently, new energy vehicles with four-wheel drive on the market usually have only one charging port (also known as a DC port), which can be set on the front drive system or the rear drive system. Figure 1 Taking the drive system shown in the figure as an example, the battery system can connect the positive electrode of the head-end battery module 1 and the negative electrode of the terminal battery module 4 to PDU1 through high-voltage cables, and then PDU1 can distribute power. In particular, PDU1 will use high-voltage cables ( Figure 1 The high-voltage cables 1 and 2 in the middle transmit the high-voltage power to PDU2, which then distributes it to the front drive system and related high-voltage loads.

[0066] It can be seen that if the battery pack is located between the front-wheel drive system and the rear-wheel drive system, due to the long distance between the two systems, a relatively long high-voltage cable is required to transmit the high-voltage power from one drive system to another. This increases the safety risk due to the relatively high risk of safety hazards caused by the long high-voltage cable.

[0067] In some optional implementations of the present application, the battery system is configured to be disposed in a chassis area between the first drive system and the second drive system. In this case, the second drive system can be directly electrically connected to the second part of the battery modules in the battery system, and then the high-voltage power of one drive system does not need to be transmitted to the other drive system over a long distance through a high-voltage cable.

[0068] Please refer to Figure 2 , compared to Figure 1 In the structure shown in FIG. 1 , the present implementation eliminates the high-voltage cable between the two drive systems and adds a high-voltage cable between the second drive system and the second battery module (e.g. Figure 2Since the high-voltage cable between the second drive system and the second battery module is relatively short, the safety risk and the use cost can be reduced.

[0069] Therefore, compared with Figure 1 The wiring structure shown in this implementation shortens the use length of the high-voltage cable, reduces safety risks, and also reduces the use cost of the high-voltage cable.

[0070] It should be noted that in this implementation, the PDU is located between the battery system and the drive system. Figure 2 In the embodiment, PDU1 is located between the battery system and the first drive system, and PDU2 is located between the battery system and the second drive system.

[0071] In some optional implementations, the battery system is configured as follows: the distance between the overall positive and negative poles of the first part of the battery module and the first power distribution unit is smaller than the distance between the overall positive and negative poles of the first part of the battery module and the second power distribution unit; the distance between the overall positive and negative poles of the second part of the battery module and the second power distribution unit is smaller than the distance between the overall positive and negative poles of the second part of the battery module and the first power distribution unit.

[0072] That is to say, the overall positive and negative poles of the first part of the battery module in the battery system are close to the first power distribution unit, while the overall positive and negative poles of the second part of the battery module are close to the second power distribution unit, which can further shorten the use length of the high-voltage cable.

[0073] In some optional implementations, the distance between the second drive system and the overall positive and negative electrodes of the second partial battery module is no more than 0.5 meters.

[0074] It should be noted that the distance between the front drive system and the rear drive system in the related art is about 2 meters, and the distance between the battery system and the two is about 0.5 meters. Therefore, in some embodiments of the present application, the high-voltage cable of about 2 meters can be reduced to about 0.5 meters, thereby greatly shortening the use length of the high-voltage cable. Moreover, if the distance between the battery system and the two is shorter, the use length of the high-voltage cable can be even shorter. It should be understood that the length of the cable between the battery module and the corresponding PDU is related to factors such as the overall length of the vehicle, the location of the drive system, and the distance between the PDU and the drive system. However, no matter how the layout is arranged, it is clear that the length of the high-voltage cable between the battery module and the PDU can be shortened by adopting the solution of the present application.

[0075] In some optional implementations, the first drive system is a rear drive system, and the second drive system is a front drive system, so that power decoupling between the front drive system and the rear drive system can be achieved.

[0076] In other optional implementations, the electric drive system also includes: a third drive system, which is used to drive a third motor of the vehicle; a fourth drive system, which is used to drive a fourth motor of the vehicle; a third part of the battery modules of the battery system are electrically connected to the third drive system for powering the third drive system, and a fourth part of the battery modules of the battery system are electrically connected to the fourth drive system for powering the fourth drive system.

[0077] That is to say, in some application scenarios, each wheel of the new energy vehicle can be driven by a drive system, for example, the left front wheel and the right front wheel are driven by the first drive system and the second drive system respectively, and the left rear wheel and the right rear wheel are driven by the third drive system and the fourth drive system respectively, thereby driving the movement of the four wheels.

[0078] It should be noted that the process of the third drive system and the fourth drive system obtaining electrical energy from the battery system and the process of driving the corresponding wheels may be similar to the corresponding processes of the first drive system and the second drive system in the previous text, and will not be repeated here.

[0079] In this implementation, one drive system can drive one wheel, so that multiple drive systems can drive multiple wheels. In this way, power decoupling between multiple drive systems can be achieved, making it easier to dynamically allocate power to multiple drive systems.

[0080] In addition, it should be clear that in order for each battery module to normally supply power to its corresponding drive system, there should be no short circuit or open circuit in each battery module, and there should be no short circuit or open circuit in the connection between each battery module and its corresponding drive system. Figure 2 In the embodiment, the second driving system cannot be connected to the negative electrode of battery module 1 and the positive electrode of battery module 2, because this will cause a short circuit.

[0081] In addition, in order to satisfy the wiring structure of the high-voltage cables in various implementations of the present application, the number N of battery modules of the above battery system may satisfy the following conditions: , and the number of battery modules M in the second part of the battery module needs to meet the following conditions: .

[0082] In some application scenarios, if the battery system includes multiple battery modules connected in series, the supply voltages of the first battery module and the second battery module are different. In addition, the first battery module and the second battery module share a common battery module. Since each battery module supplies power to a different drive system, this may cause the voltages of the first battery module and the second battery module in the battery system to be inconsistent, which may shorten the vehicle's cruising range.

[0083] For example, in Figure 2 In the process of charging, the four battery modules can discharge to the first drive system together, and the battery modules 2 and 3 can discharge to the second drive system when discharging to the first drive system. Therefore, in the same discharge time, the voltage of the battery modules 2 and 3 is lower than that of the battery modules 1 and 4. In the recharging process, the battery modules 2 and 3 can be recharged through the second drive system when recharging through the first drive system. Therefore, in the same recharging time, the voltage of the battery modules 2 and 3 is higher than that of the battery modules 1 and 4. Therefore, there may be a problem of voltage inconsistency between the multiple battery modules in the second part of the battery modules and the battery modules in the first part of the battery modules.

[0084] Furthermore, due to the voltage inconsistency between the first battery module and the second battery module, in order to reduce the risk of over-discharge or over-charge of the battery module, the discharge process and the recharge process will be restricted, which will shorten the vehicle's cruising range.

[0085] In order to improve this situation, the inventor took into account that since multiple battery modules in the battery system are connected in series, for the same part of the battery modules, the current flowing through the multiple battery modules therein is the same, so the voltage difference between the first part of the battery modules and the second part of the battery modules can be reduced through power control.

[0086] Furthermore, taking the voltage of the first battery module as an example, which is higher than the voltage of the second battery module, on the one hand, the driving power provided by the first driving system can be increased, thereby reducing the voltage of the first battery module; on the other hand, the driving power provided by the second driving system can be reduced, thereby increasing the voltage of the second battery module. Therefore, the voltage difference between the first battery module and the second battery module can be reduced through the above two aspects.

[0087] It should be noted that the battery system will exchange electric energy with the corresponding drive system during the discharge process and the recharge process. Therefore, the corresponding control method can be implemented by the controller during the discharge process and the recharge process.

[0088] In some application scenarios, the above-mentioned controller may be, for example, a vehicle's VCU (Vehicle Control Unit) or a power domain controller, or may be other separate controllers, which is not limited in this application.

[0089] Please refer to Figure 5 , which shows a flow chart of a control method performed by a controller provided in an embodiment of the present application. Figure 5 As shown, the controller may execute the following steps 501 and / or 502 .

[0090] Step 501, during the discharge process of the battery system, according to the driving power requirement, controlling the first driving system and / or the second driving system to provide driving power to reduce the voltage difference between the first battery module and the second battery module; The above driving power requirement can be used to represent the driving power that the entire driving system needs to provide externally.

[0091] It should be noted that when the drive system provides driving power to the outside, the first battery module can provide electric energy to the first drive system, so that the first drive system provides driving power to the outside. The second battery module can also provide electric energy to the second drive system, so that the second drive system provides driving power to the outside, or the first drive system and the second drive system can provide driving power to the outside together.

[0092] by Figure 2 Taking the structure shown as an example, during the discharge process of the battery system, the voltage of the first battery module is greater than the voltage of the second battery module. In order to reduce the voltage difference between the two, the driving power provided by the two driving systems can be controlled. Here, in order to determine whether the voltage of the first battery module is greater than the voltage of the second battery module, for example, it can be determined by measuring each battery module by a voltage sensor, or by estimating the SOC corresponding to each battery module.

[0093] Specifically, if the driving power demand is large, the first driving system can be controlled to provide driving power first, and only when the driving power provided by the first driving system cannot meet the driving power demand, the second driving system is coordinated to provide driving power together. In addition, if the driving power demand is small, only the first driving system can be controlled to provide it. In this way, the first driving system can provide more driving power to the outside, thereby reducing the voltage of the first part of the battery module. Alternatively, the second driving system can provide less driving power to the outside, thereby increasing the voltage of the second part of the battery module. In this way, the voltage difference between the first part of the battery module and the second part of the battery module can be reduced.

[0094] Step 502, during the recharging process of the battery system, the braking power of the first drive system and / or the second drive system is controlled according to the recharging power requirement of the battery system to reduce the voltage difference between the first part of the battery module and the second part of the battery module.

[0095] In the regenerative braking of new energy vehicles, when the vehicle slows down or brakes, the electric motor can reverse to become a generator, converting the kinetic energy of the wheels into electrical energy and feeding it back to the battery system. In this process, the above braking power can be understood as the energy rate recovered by the drive system from the vehicle movement, that is, the amount of electrical energy that can be converted and stored per unit time.

[0096] In some application scenarios, if the recharging power demand is large, the second drive system can be controlled to recharge first, so as to convert the kinetic energy obtained from the vehicle rotation process into electrical energy to recharge the second battery module. When the braking power of the second drive system is not enough to meet the recharging power demand, the first drive system is coordinated to recharge together. In addition, if the recharging power demand is small, only the second drive system can be controlled to recharge.

[0097] In this way, the braking power of the second drive system can be increased, thereby increasing the voltage of the second battery module. Also, the braking power of the first drive system can be reduced, thereby reducing the voltage of the first battery module. Therefore, the voltage difference between the first battery module and the second battery module can be reduced.

[0098] Therefore, in the present application, by adaptively controlling the driving power or braking power of the first driving system and / or the second driving system during the discharge and / or recharging process of the battery system, the voltage inconsistency between the first part of the battery module and the second part of the battery module can be improved in different processes, thereby improving the vehicle's cruising range.

[0099] For some alternative implementations, see Figure 6 If the first drive system is a rear-wheel drive system and the second drive system is a front-wheel drive system, the step of controlling the first drive system and / or the second drive system to provide drive power according to the drive power requirement in step 501 above includes: Sub-step 5011, if the driving power requirement is not greater than the first driving power of the first driving system, providing driving power through the first driving system; Sub-step 5012: If the driving power requirement is greater than the first driving power of the first driving system, the driving power is provided by the first driving system and the second driving system.

[0100] The first driving power can be, for example, the maximum allowable power that the first driving system can provide during the driving process, or a larger allowable power that is close to the maximum allowable power. In this way, if the driving power demand is not greater than the first driving power, it means that the first driving power provided by the first driving system can meet the driving power demand, and then it can be provided only by the first driving system, thereby reducing the voltage of the first part of the battery module. When the driving power demand is greater than the first driving power, it means that the driving power provided by the first driving system cannot meet the driving power demand, and then the two driving systems can be controlled to provide together to meet the driving power demand.

[0101] In this implementation, the first drive system can be adaptively used to provide drive power, or used together with the second drive system to provide drive power, based on the magnitude relationship between the drive power requirement and the first drive power. In this way, the drive power requirement and the voltage inconsistency can be taken into account, so that the voltage difference between the first battery module and the second battery module can be reduced on the basis of meeting the drive power requirement.

[0102] In some optional implementations, the step 501 of controlling the first drive system and / or the second drive system to provide drive power according to the drive power requirement further includes: Step 1, determining a first SOC according to a first current flowing through the first part of the battery modules; The first current can be, for example, Figure 2-Figure 4 Any I1 in the driving system shown. In some application scenarios, the controller may, for example, refer to a current-SOC relationship table to obtain a first SOC corresponding to the first current.

[0103] Step 2, determining a second SOC according to a second current flowing through the second battery module and the first current; The second current can be, for example, Figure 2-Figure 4 Any I2 in the drive system shown.

[0104] It should be noted that during the discharge process, the second battery module may discharge to the second drive system in addition to the first drive system. At this time, the total discharge current of the second battery module is the sum of the first current and the second current. Therefore, the second SOC is the SOC corresponding to the above current sum.

[0105] Furthermore, the controller may also refer to a current-SOC relationship table, for example, to obtain the second SOC.

[0106] It should be understood that there are many ways to calculate SOC based on current, such as the ampere-hour integration method and the open circuit voltage method. In addition, when calculating SOC, parameters such as initial SOC, current integration time, and temperature compensation can also be combined, which are not described in detail in the embodiments of the present application.

[0107] Step 3, determining a first allowable current flowing through the first drive system according to the smaller one of the first SOC and the second SOC; The first allowed current is also the current that the first driving system is allowed to flow through.

[0108] It should be noted that, in order to reduce the risk of over-discharge of the first battery module or the second battery module, the controller may determine the first allowable current according to the smaller of the first SOC and the second SOC. In some application scenarios, for example, the current corresponding to the smaller SOC may be queried in the current-SOC relationship table, and the current may be determined as the first allowable current.

[0109] Step 4: Determine a first driving power of the first driving system according to the first allowed current and the voltage of the first driving system.

[0110] In this way, the first driving power is the maximum driving power that the first driving system can provide when the risk of over-discharge is low. Then, when the driving power of the first driving system and the second driving system is controlled by the relationship between the maximum driving power and the driving power requirement, the first driving system can be used to the maximum extent to improve the voltage inconsistency between the first battery module and the second battery module, while reducing the risk of over-discharge of the second battery module.

[0111] Furthermore, the present implementation determines the first driving power through the SOC value. Since the SOC value can more accurately reflect the energy level that can currently be provided by some battery modules, a more accurate first driving power can be obtained.

[0112] It should be noted that in addition to using SOC to determine the first driving power, for example, the first driving power can also be determined by using the voltage of some battery modules. Those skilled in the art can choose according to actual conditions, and this application does not impose any restrictions on this.

[0113] Thus, if the driving power requirement is greater than the first driving power of the first driving system, the first driving system and the second driving system provide driving power in the above sub-step 5012, including: First, if the driving power requirement is greater than the first driving power of the first driving system, determining the remaining driving power requirement according to the driving power requirement and the first driving power; For example, the controller may subtract the power value P corresponding to the driving power requirement from the first driving power P1, so as to obtain the power value P2 corresponding to the remaining driving power requirement.

[0114] Then, determining a current supplied to the second driving system according to the remaining driving power requirement and the voltage of the second driving system; For example, the controller may divide the power value P2 corresponding to the remaining driving power demand by the voltage U2 of the second driving system to obtain the current I′2 supplied to the second driving system (ie, I2=P2 / U2).

[0115] Then, according to the maximum allowable output current of the second drive system and the first current flowing through the first drive system, determining the allowable current supplied to the second drive system; For example, the controller may subtract the maximum discharge allowable current I3 from the first current I1 to obtain the allowable current supplied to the second drive system.

[0116] Then, the smaller of the current supplied to the second drive system and the allowed current is determined as the target allowed current supplied to the second drive system; for example, after obtaining the difference between I3 and I1, the smaller of the difference and I'2 is determined as the target allowed current.

[0117] Finally, according to the target allowable current, the second driving system is controlled to provide driving power.

[0118] In this implementation, the second drive system is controlled to provide drive power to meet the drive power requirement only when the first drive power of the first drive system is insufficient to meet the drive power requirement. In this way, the voltage inconsistency between the first battery module and the second battery module can be improved while meeting the drive power requirement. In addition, since the target allowable current is the smaller of the current supplied to the second drive system and the allowable current, after the target allowable current is supplied to the second drive system, the risk of over-discharge of the second battery module can be reduced.

[0119] During the recharging process of the battery system, due to the voltage difference between the first battery module and the second battery module, the SOC between the battery modules may be different. Therefore, recharging can be performed based on the size relationship between the SOC of the first battery module and the SOC of the second battery module.

[0120] For some alternative implementations, see Figure 7If the first drive system is a rear-wheel drive system and the second drive system is a front-wheel drive system, the step 502 described in the above-mentioned step of controlling the first drive system and / or the second drive system to provide braking power according to the recharging power requirement of the battery system includes: Step 5021, determining a first SOC corresponding to the first part of the battery modules and a second SOC corresponding to the second part of the battery modules; Here, the process of determining the first SOC and the second SOC may be the same or similar to the corresponding part in the foregoing text, and will not be repeated here.

[0121] Step 5022: if the second SOC is less than the first SOC, then if the recharging power requirement is not greater than the second recharging allowable power corresponding to the second driving system, increase the braking power of the second driving system; Step 5023: if the second SOC is less than the first SOC, then when the recharging power requirement is greater than the second recharging allowable power corresponding to the second driving system, increasing the braking power of the first driving system; The second recharging allowable power may be, for example, the maximum braking power allowed for the second drive system during the recharging process, or a larger braking power close to the maximum braking power.

[0122] It should be noted that if the second SOC is less than the first SOC, it means that the voltage between the first part of the battery module and the second part of the battery module is inconsistent during the power exchange process, and the voltage of the second part of the battery module is lower than the voltage of the first part of the battery module. Therefore, it is possible to further judge the relationship between the recharging power demand and the second recharging allowable power corresponding to the second drive system to determine whether controlling the second drive system for recharging can meet the recharging power demand.

[0123] If the recharging power requirement is not greater than the second recharging allowable power, it means that the recharging power requirement can be met by the second drive system, and then only the second drive system can be used to increase the voltage of the second battery module. At this time, for example, the second recharging allowable power corresponding to the second drive system can be divided by its voltage to obtain the corresponding recharging allowable current to recharge the second drive system.

[0124] In addition, when the recharging power demand is greater than the second recharging allowed power, it means that the recharging of the second drive system cannot meet the recharging power demand. Since the platform voltage of the first drive system is relatively high, the recharging power demand can be met more quickly by recharging through the first drive system, so only the first drive system can be controlled for recharging. Furthermore, the controller can also control the two drive systems to recharge together to take into account both meeting the recharging power demand and increasing the voltage of the second battery module.

[0125] Step 5024: If the second SOC is not less than the first SOC, the braking power of the first drive system is increased. Here, when the second SOC is not less than the first SOC, if the first drive system is a rear drive system, the recharging efficiency can be improved by controlling the first drive system to recharge.

[0126] In this implementation, the first drive system or the second drive system is adaptively controlled to perform recharging based on the size relationship between the first SOC and the second SOC, which improves the control accuracy to a certain extent. In addition, during the recharging process, the recharging efficiency of the first drive system and the second drive system can be taken into account, which also improves the vehicle's cruising range to a certain extent.

[0127] Please continue reading Figure 7 After controlling the first drive system to provide braking power, controlling the braking power of the first drive system and / or the second drive system according to the recharging power requirement of the battery system in step 502 further includes: Step 5025: determining a first recharge allowable current corresponding to the first drive system according to the larger one of the first SOC and the second SOC; Here, the controller may also refer to a current-SOC relationship table, for example, to obtain the first recharging permission current.

[0128] It should be noted that since the current battery system is in the recharging process, it is different from the discharging process. In order to reduce the overcharging risk of the second part of the battery module, the allowable current supplied to the first drive system is determined according to the larger of the first SOC and the second SOC. This allowable current is also the above-mentioned first recharging allowable current.

[0129] Step 5026, determining a second recharge allowable current corresponding to the second drive system according to the second SOC; In some application scenarios, the controller may also refer to a current-SOC relationship table, for example, to obtain a second recharging permission current corresponding to the second SOC.

[0130] Step 5027: If the current difference between the second recharge permission current and the first recharge permission current is greater than 0, the braking power of the second drive system is controlled according to the current difference.

[0131] Among them, when the above current difference is greater than 0, the second recharge allowable current is greater than the first recharge allowable current, and the second part of the battery modules is at risk of overcharging. Therefore, by continuing to recharge through the current difference, the second recharge allowable current can be made not greater than the first recharge allowable current, thereby reducing the risk of overcharging the second part of the battery modules.

[0132] In some optional implementations, after controlling the first drive system to provide braking power, controlling the braking power of the first drive system and / or the second drive system according to the recharging power requirement of the battery system in step 502 further includes: If the current recharging power demand is greater than the first recharging allowable power corresponding to the first drive system, then when the current difference between the second recharging allowable current and the first recharging allowable current is greater than 0, the braking power of the second drive system is controlled according to the current difference; If the current recharging power demand is not greater than the first recharging allowable power, the first SOC and the second SOC are redetermined to re-control the braking power of the first drive system and / or the second drive system.

[0133] In this implementation, the second recharge allowable current can be made no greater than the first recharge allowable current, thereby reducing the risk of overcharging of the second portion of battery modules.

[0134] In some optional implementations, if the battery system is fast charged, the larger of the first SOC and the second SOC can be determined, and the current corresponding to the larger one can be determined as the fast charge current to charge the battery system. When the first SOC is greater than or equal to 100%, or when the second SOC is greater than or equal to 100%, charging can be stopped to protect the battery.

[0135] Those skilled in the art will appreciate that, in the above method of a specific embodiment, the order in which the steps are written does not imply a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of the steps should be determined by their functions and possible internal logic.

[0136] Based on the same inventive concept, an embodiment of the present application provides a vehicle, which includes the electric drive system in any of the above implementations.

[0137] In addition, in the embodiments provided in the present application, it should be understood that the disclosed system or method can be implemented in other ways. The system embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of the system or unit can be electrical, mechanical or other forms.

[0138] In addition, the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0139] Furthermore, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0140] In this document, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0141] The above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An electric drive system, characterized in that: include: a first drive system, the first drive system being used to drive a first portion of wheels of the vehicle; a second drive system, the second drive system being used to drive a second portion of wheels of the vehicle; A battery system, the battery system comprising a plurality of battery modules, a first portion of the battery modules of the battery system being electrically connected to the first drive system for supplying power to the first drive system; A second part of the battery modules of the battery system is electrically connected to the second drive system for supplying power to the second drive system; The first part of the battery module is connected in parallel with the second part of the battery module; or, The battery system includes a plurality of battery modules connected in series, the first portion of battery modules and the second portion of battery modules have different supply voltages, and the first portion of battery modules and the second portion of battery modules have common battery modules.

2. The electric drive system according to claim 1, characterized in that: The electric drive system further comprises: A first power distribution unit, the first power distribution unit is connected to the overall positive and negative electrodes of the first part of the battery module through a high-voltage cable, and is connected to the power input interface of the first drive system through another high-voltage cable; A second power distribution unit, wherein the second power distribution unit is connected to the overall positive and negative electrodes of the second battery module through a high-voltage cable, and is connected to the power input interface of the second drive system through another high-voltage cable.

3. The electric drive system according to claim 2, characterized in that: The battery system is configured to be disposed in a chassis area between the first drive system and the second drive system.

4. The electric drive system according to claim 3, characterized in that: The battery system is configured such that: the distance between the first part of the battery module's overall positive and negative electrodes and the first power distribution unit is smaller than the distance between the first part of the battery module's overall positive and negative electrodes and the second power distribution unit; The distance between the overall positive and negative poles of the second battery module and the second power distribution unit is smaller than the distance between the overall positive and negative poles of the second battery module and the first power distribution unit.

5. The electric drive system according to any one of claims 1 to 4, characterized in that: The first drive system is a rear-wheel drive system, and the second drive system is a front-wheel drive system.

6. The electric drive system according to any one of claims 1 to 4, characterized in that: Also includes: a third drive system, the third drive system being used to drive a third portion of wheels of the vehicle; a fourth drive system, the fourth drive system being used to drive a fourth portion of wheels of the vehicle; The third battery module of the battery system is electrically connected to the third drive system for supplying power to the third drive system, and the fourth battery module of the battery system is electrically connected to the fourth drive system for supplying power to the fourth drive system.

7. The electric drive system according to claim 1, characterized in that: The first portion of battery modules is all the battery modules of the battery system, and the second portion of battery modules is a portion of battery modules connected in series in the battery system.

8. The electric drive system according to any one of claims 1 to 4 or 7, characterized in that: The electric drive system further includes a controller, which is configured to: During the discharge process of the battery system, the first drive system and / or the second drive system is controlled to provide drive power according to the drive power requirement, so as to reduce the voltage difference between the first part of the battery modules and the second part of the battery modules.

9. The electric drive system according to claim 8, characterized in that: If the first drive system is a rear-wheel drive system and the second drive system is a front-wheel drive system, the controller is further configured to: If the driving power requirement is not greater than the first driving power of the first driving system, providing driving power through the first driving system; If the driving power requirement is greater than the first driving power of the first driving system, the driving power is provided by the first driving system and the second driving system.

10. The electric drive system according to claim 9, characterized in that: The controller is further configured to: Determining a first SOC according to a first current flowing through the first portion of the battery modules; determining a second SOC according to a second current flowing through the second battery module and the first current; determining a first allowable current flowing through the first drive system according to the smaller of the first SOC and the second SOC; A first driving power of the first driving system is determined according to the first allowed current and the voltage of the first driving system.

11. The electric drive system according to claim 9, characterized in that: If the driving power requirement is greater than the first driving power of the first driving system, the controller is further configured to: If the driving power requirement is greater than the first driving power of the first driving system, determining a remaining driving power requirement according to the driving power requirement and the first driving power; determining a current supplied to the second driving system according to the remaining driving power requirement and the voltage of the second driving system; determining an allowable current supplied to the second drive system according to a maximum allowable output current of the second drive system and a first current flowing through the first drive system; determining the smaller of the current supplied to the second drive system and the allowable current as a target allowable current supplied to the second drive system; The second drive system is controlled to provide drive power according to the target allowable current.

12. The electric drive system according to any one of claims 1 to 4 or 7, characterized in that: The electric drive system further includes a controller, which is configured to: During the recharging process of the battery system, the braking power of the first drive system and / or the second drive system is controlled according to the recharging power requirement of the battery system to reduce the voltage difference between the first part of the battery module and the second part of the battery module.

13. The electric drive system according to claim 12, characterized in that: If the first drive system is a rear-wheel drive system and the second drive system is a front-wheel drive system, the controller is further configured to: Determine a first SOC corresponding to the first portion of battery modules and a second SOC corresponding to the second portion of battery modules; If the second SOC is less than the first SOC, the braking power of the second driving system is increased when the recharging power demand is not greater than the second recharging allowable power corresponding to the second driving system; If the second SOC is less than the first SOC, when the recharging power requirement is greater than the second recharging allowable power corresponding to the second driving system, increasing the braking power of the first driving system; If the second SOC is not less than the first SOC, the braking power of the first driving system is increased.

14. The electric drive system according to claim 13, characterized in that: The controller is further configured to: after controlling the first drive system to provide braking power, determine a first recharge allowable current corresponding to the first drive system according to the larger of the first SOC and the second SOC; determining a second recharging allowable current corresponding to the second drive system according to the second SOC; If the current difference between the second recharge permission current and the first recharge permission current is greater than 0, the braking power of the second drive system is controlled according to the current difference.

15. The electric drive system according to claim 14, characterized in that: The controller is further configured to: after controlling the first drive system to provide braking power, if the current recharging power demand is greater than the first recharging allowable power corresponding to the first drive system, control the braking power of the second drive system according to the current difference when the current difference between the second recharging allowable current and the first recharging allowable current is greater than 0; If the current recharging power demand is not greater than the first recharging allowable power, the first SOC and the second SOC are redetermined to re-control the braking power of the first drive system and / or the second drive system.

16. A control method for an electric drive system, characterized in that: Applied to the electric drive system according to any one of claims 1 to 7, the method comprises: During the discharge process of the battery system, according to the driving power requirement, the first driving system and / or the second driving system are controlled to provide driving power to reduce the voltage difference between the first battery module and the second battery module; and / or, During the recharging process of the battery system, the braking power of the first drive system and / or the second drive system is controlled according to the recharging power requirement of the battery system to reduce the voltage difference between the first part of the battery module and the second part of the battery module.

17. A vehicle, characterized in that: include: An electric drive system as claimed in any one of claims 1 to 15.

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