Electric drive system, control method, and vehicle

Abstract

The present application provides an electric drive system, a control method, and a vehicle. The electric drive system includes: a first drive system for driving a first part of the vehicle wheels; a second drive system for driving a second part of the vehicle wheels; a battery system including a plurality of battery modules, a first part 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 being electrically connected to the second drive system for supplying power to the second drive system; the first part of the battery modules being in parallel with the second part of the battery modules; or, the plurality of battery modules included in the battery system being connected in series, and the power supply voltages of the first part of the battery modules and the second part of the battery modules being different; there being a shared battery module between the first part of the battery modules and the second part of the battery modules. In this way, the power supply can be dynamically allocated according to requirements.

Description

Technical Field

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

[0002] In the power supply system of a traditional four-wheel drive electric vehicle, the battery pack is usually designed as a high-voltage unit (such as 800V) as the single power source for the whole vehicle. Then, the battery pack can distribute power to the front and rear drive systems through a Power Distribution Unit (PDU for short). 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 requirements. Summary of the Invention

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

[0004] In a first aspect, the embodiments of this application provide a drive system, including: a first drive system for driving the first part of the vehicle's wheels; a second drive system for driving the second part of the vehicle's wheels; and a battery system including a plurality of battery modules. The first part of the battery modules of the battery system is electrically connected to the first drive system to supply power to the first drive system; the second part of the battery modules of the battery system is electrically connected to the second drive system to supply power to the second drive system. In this way, the battery system is decoupled into the first part of the battery modules and the 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 requirements. Therefore, power can be dynamically distributed according to requirements.

[0005] In addition, the first part of the battery modules is connected in parallel with the second part of the battery modules. In this way, with this partitioned parallel connection scheme, the two parts of the battery modules can independently supply power to their respective drive systems, achieving power supply decoupling, which is convenient for dynamically distributing power and power output according to requirements. Moreover, when a failure occurs in one part of the battery modules or the drive system, the other part can still continue to work, thereby improving the overall reliability of the system.

[0006] In addition, a plurality of battery modules included in the battery system are connected in series, and the power supply voltages of the first part of the battery modules and the second part of the battery modules 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 with no strong high-power motor demand can reduce its platform voltage, thereby reducing the usage cost of low-power high-voltage loads.

[0007] In addition, there are shared battery modules between the first part of the battery modules and the second part of the battery modules. In this way, it is convenient to conduct overall management of the plurality of battery modules. Moreover, even if an abnormal condition occurs in a certain battery module, a certain voltage output can be maintained through the shared battery modules, reducing the risk that any drive system cannot operate due to the failure of a single battery module.

[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 part of the battery modules 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 part of the battery modules 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 decoupling the battery modules in the battery system into the first part of the battery modules and the second part of the battery modules, each part of the battery modules can adaptively distribute power through the corresponding power distribution unit, thus facilitating the realization of the purpose of dynamically distributing power.

[0009] Optionally, the battery system is configured to be disposed in the chassis area between the first drive system and the second drive system. At this time, the second drive system can be directly electrically connected to the second part of the battery modules in the battery system, and then there is no need to transmit the high-voltage power of one drive system 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 usage length of the high-voltage cable can be shortened, the safety risk is reduced, and the usage cost of the high-voltage cable is also reduced.

[0010] Optionally, the battery system is configured such that the distance between the overall positive and negative electrodes of the first part of the battery modules and the first power distribution unit is less than the distance between the overall positive and negative electrodes of the first part of the battery modules and the second power distribution unit; the distance between the overall positive and negative electrodes of the second part of the battery modules and the second power distribution unit is less than the distance between the overall positive and negative electrodes of the second part of the battery modules and the first power distribution unit. This can further shorten the usage length of the high-voltage cable.

[0011] Optionally, the first drive system is a rear-wheel drive system, and the second drive system is a front-wheel drive system. In this way, power decoupling between the front-wheel drive system and the rear-wheel drive system can be achieved.

[0012] Optionally, the electric drive system further includes: a third drive system for driving a third part of the vehicle wheels; a fourth drive system for driving a fourth part of the vehicle wheels; a third part of the battery modules of the battery system is electrically connected to the third drive system for supplying power to the third drive system, and a fourth part of the battery modules of the battery system is electrically connected to the fourth drive system for supplying power to the fourth drive system. In this way, power decoupling between multiple drive systems can be achieved, facilitating dynamic power distribution to multiple drive systems.

[0013] Optionally, 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 a part of the battery modules connected in series in the battery system. In this way, it is convenient to dynamically distribute power according to the power demand.

[0014] Optionally, the electric drive system further includes a controller configured 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 part of the battery modules and the second part of the battery modules. 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 part of the battery modules and the second part of the battery modules is improved, and the driving range of the vehicle is increased.

[0015] 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 configured to: if the drive power demand is not greater than the first drive power of the first drive system, provide drive power through the first drive system; if the drive power demand is greater than the first drive power of the first drive system, provide drive power through the first drive system and the second drive system. In this way, both the drive power demand and the voltage inconsistency can be taken into account, so that the voltage difference between the first part of the battery modules and the second part of the battery modules can be reduced on the basis of meeting the drive power demand.

[0016] Optionally, the controller is further configured to: determine a first state of charge (SOC) according to a first current flowing through the first part of the battery modules; determine a second SOC according to a second current flowing through the second part of the battery modules and the first current; determine a first allowable current flowing through the first drive system according to the smaller value 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 part of the battery modules can be reduced, and a more accurate first drive power can be obtained.

[0017] Optionally, if the drive power demand is greater than the first drive power of the first drive system, the controller is further configured to: if the drive power demand is greater than the first drive power of the first drive system, determine a remaining drive power demand according to the drive power demand and the first drive power; determine a current supplied to the second drive system according to the remaining drive power demand and the voltage of the second drive system; determine an allowable current supplied to the second drive system according to the maximum allowable output current of the second drive system and the first current flowing through the first drive system; determine the smaller value of the current supplied to the second drive system and the allowable current as a target allowable current supplied to the second drive system; and control the second drive system to provide drive power according to the target allowable current. In this way, when the first drive power of the first drive system is not sufficient to meet the drive power demand, the second drive system is controlled to provide drive power to meet the drive power demand. In this way, the voltage inconsistency between the first part of the battery modules and the second part of the battery modules can be improved while meeting the drive power demand. Moreover, since the target allowable current is the smaller value of the determined current supplied to the second drive system and the allowable current, after supplying the target allowable current to the second drive system, the risk of over-discharge of the second part of the battery modules can be reduced.

[0018] Optionally, the electric drive system further includes a controller, which is configured to: during the charging process of the battery system, control the braking power of the first drive system and / or the second drive system according to the charging power demand of the battery system, so as to reduce the voltage difference between the first part of the battery modules and the second part of the battery modules. In this way, by adaptively controlling the braking power of the first drive system and / or the second drive system during the charging process of the battery system, the voltage inconsistency between the first part of the battery modules and the second part of the battery modules is improved, and the driving range of the vehicle is increased.

[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 configured to: determine a first State of Charge (SOC) corresponding to the first part of the battery modules and a second SOC corresponding to the second part of the battery modules; if the second SOC is less than the first SOC, increase the braking power of the second drive system when the recharge power demand is not greater than the second recharge allowable power corresponding to the second drive system; if the second SOC is less than the first SOC, increase the braking power of the first drive system when the recharge power demand is greater than the second recharge allowable power corresponding to the second 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, based on the magnitude relationship between the first SOC and the second SOC, the first drive system or the second drive system is adaptively controlled for recharge, which improves the control accuracy to a certain extent. Additionally, during the recharge process, the recharge efficiency of both 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 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 value of the first SOC and the second SOC; determine a 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 this 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.

[0021] Optionally, the controller is further configured 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, control the braking power of the second drive system according to the current difference when the current difference between the second recharge allowable current and the first recharge allowable current is greater than 0; if the current recharge power demand is not greater than the first recharge allowable power, re-determine 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 modules.

[0022] Second aspect, an embodiment of the present application provides a control method for an electric drive system, including: during the discharge process of the battery system, controlling the first drive system and / or the second drive system to provide drive power according to the drive power demand, so as to reduce the voltage difference between the first part of the battery modules and the second part of the battery modules; and / or, during the recharge process of the battery system, controlling the braking power of the first drive system and / or the second drive system according to the recharge power demand of the battery system, so as to reduce the voltage difference between the first part of the battery modules and the second part of the battery modules.

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

[0024] Optionally, determine the first SOC according to the first current flowing through the first part of the battery modules; determine the second SOC according to the second current flowing through the second part of the battery modules and the first current; determine the first allowable current flowing through the first drive system according to the smaller value of the first SOC and the second SOC; determine the first drive power of the first drive system according to the first allowable current and the voltage of the first drive system.

[0025] Optionally, if the drive power demand is greater than the first drive power of the first drive system, thus, if the drive power demand is greater than the first drive power of the first drive system, determine the remaining drive power demand according to the drive power demand and the first drive power; determine the current supplied to the second drive system according to the remaining drive power demand and the voltage of the second drive system; determine the allowable current supplied to the second drive system according to the maximum allowable output current of the second drive system and the first current flowing through the first drive system; determine the target allowable current supplied to the second drive system as the smaller value of the current supplied to the second drive system and the allowable current; control the second drive system to provide drive 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, determine the first SOC corresponding to the first part of the battery modules and the second SOC corresponding to the second part of the battery modules; if the second SOC is less than the first SOC, increase the braking power of the second drive system when the recharge power demand is not greater than the second recharge allowable power corresponding to the second drive system; if the second SOC is less than the first SOC, increase the braking power of the first drive system when the recharge power demand is greater than the second recharge allowable power corresponding to the second drive system; if the second SOC is not less than the first SOC, increase the braking power of the first drive system.

[0027] Optionally, 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 value 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.

[0028] Optionally, 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, control the braking power of the second drive system according to the current difference when the current difference between the second recharge allowable current and the first recharge allowable current is greater than 0; if the current recharge power demand is not greater than the first recharge allowable power, re-determine the first SOC and the second SOC 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, including: an electric drive system as provided in the first aspect.

[0030] Other features and advantages of the present application will be described in the subsequent description, and, in part, will become apparent from the description, or will be understood by implementing the embodiments of the present application. The objectives and other advantages of the present application can be achieved and obtained by the structures specifically pointed out in the written description, claims, and drawings. Description of the Drawings

[0031] To more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the accompanying drawings required for use in the embodiments of the present application. It should be understood that the following drawings only show certain embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0032] Figure 1 It is a structural diagram of an electric drive system in an existing new energy vehicle;

[0033] Figure 2 It is a structural diagram of the first electric drive system provided by the embodiment of the present application;

[0034] Figure 3 It is a structural diagram of the second electric drive system provided by the embodiment of the present application;

[0035] Figure 4 It is a structural diagram of the third electric drive system provided by the embodiment of the present application;

[0036] Figure 5 It is a flowchart of a control method executed by a controller provided by the embodiment of the present application;

[0037] Figure 6 It is a flowchart of a control method executed by a controller during the discharge process provided by the embodiment of the present application;

[0038] Figure 7 It is a flowchart of a control method executed by a controller during the recharge process provided by the embodiment of the present application. Detailed implementation manners

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all embodiments. The components of the embodiments of the present application usually 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 present application to be protected, but only 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 creative efforts belong to the scope of protection of the present application.

[0040] It should be noted that similar reference numerals and letters denote similar items in the following drawings. Therefore, 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 the present application, terms such as "first", "second", etc. are only used for distinguishing descriptions and cannot be construed as indicating or implying relative importance.

[0041] It should be noted that, without conflict, the embodiments in the present application or the technical features in the embodiments can be combined.

[0042] In the related art, there is a problem that power cannot be dynamically allocated according to requirements. For example, in Figure 1 an electric drive system of an existing new energy vehicle shown, it includes a front drive system, a rear drive system, and a battery pack. Among them, 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 distribute power to the front drive system through another power distribution unit. Further, the battery pack includes a plurality of battery modules, and the number of battery modules can be set according to actual requirements. Currently Figure 1 it includes 4 serially connected battery modules, namely battery module 1, battery module 2, battery module 3, and battery module 4, and the four battery modules have a fixed topological structure as Figure 1 shown. However, the front and rear drive systems must passively adapt to the fixed topological structure 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), so that power cannot be dynamically allocated according to requirements. For example, if the battery pack can provide a voltage of 800V, the voltage distributed to the rear drive system and the front drive system is both 800V. In this way, power cannot be dynamically allocated according to requirements (for example, distribute 800V voltage to the rear drive system and 400V to the front drive system).

[0043] Therefore, 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. Among them, the first drive system is used to drive the first part of the wheels of the vehicle; the second drive system is used to drive the second part of the wheels of the vehicle; the battery system includes a plurality of battery modules, and the first part of the battery modules of the battery system is electrically connected to the first drive system and used to supply power to the first drive system; the second part of the battery modules of the battery system is electrically connected to the second drive system and used to supply power to the second drive system.

[0044] The above first drive system can be, for example, a front drive system or a rear drive system. Among them, 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.

[0045] The above-mentioned first part of the wheels can be one wheel or multiple wheels; the above-mentioned second part of the wheels can be one wheel or multiple wheels, without limitation here. For example, the first part of the wheels and the second part of the wheels can be the front wheels and the rear wheels respectively. Or, the first part of the wheels is the left front wheel and the second part of the wheels is the right front wheel.

[0046] Furthermore, the first drive system includes a first motor, and the second drive system includes a second motor. The first motor and the second motor are respectively used to drive the corresponding wheels to rotate. Among them, if the first drive system is a front-wheel drive system, the first motor can be used to drive the vehicle's front wheels to rotate, and the second motor can be used to drive the vehicle's rear wheels to rotate, for example; 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 is used to drive the vehicle's front wheels to rotate.

[0047] The multiple battery modules included in the above battery system can be connected in series or in parallel, without limitation here.

[0048] Please refer to Figure 2 , which shows an electric drive system provided by an embodiment of the present application. It should be understood that, in order to form a contrast effect with the above Figure 1 , the battery system of Figure 2 also includes 4 series-connected battery modules, namely battery module 1, battery module 2, battery module 3, and battery module 4. In fact, the number of battery modules can be adaptively set according to actual needs.

[0049] As Figure 2 shows, 4 series-connected battery modules constitute the first part of the battery modules. The positive terminal of battery module 1 is used as the overall positive terminal of the first part of the battery modules, and the negative terminal of battery module 4 is used as the overall negative terminal of the first part of the battery modules. Both are respectively electrically connected to the first drive system. The positive terminal of battery module 2 is used as the overall positive terminal of the second part of the battery modules, and the negative terminal of battery module 3 is used as the overall negative terminal of the second part of the battery modules. Both are respectively electrically connected to the second drive system.

[0050] It should be noted that in some other application scenarios, the above battery system can also be a structure including battery modules that are not all connected in series. For example, the battery system includes a first part of the battery modules and a second part of the battery modules. The first part of the battery modules includes multiple series-connected battery modules, and the second part of the battery modules also includes multiple series-connected battery modules. 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 and the second part of the battery modules are connected in parallel. In this way, the overall positive and negative electrodes of the first part of the battery modules can also be respectively electrically connected to the first drive system, and the overall positive and negative electrodes of the second part of the battery modules are electrically connected to the second drive system.

[0051] 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.

[0052] In this implementation, the battery system is decoupled into a first part of battery modules and a second part of 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 requirements (for example, the first drive system selects an 800V power source, and the second drive system selects a 400V power source). Therefore, this implementation can dynamically allocate power according to requirements. In addition, when a power supply abnormality occurs in a certain part of the battery modules, the other part of the battery modules can still supply power normally to enable the corresponding drive system of the vehicle to work normally.

[0053] In some alternative implementations, the first part of battery modules is connected in parallel with the second part of battery modules. That is, the first part of battery modules and the second part of battery modules are respectively connected to the first drive system and the second drive system, and at the same time, these two parts of battery modules are connected in parallel. By adopting this partitioned parallel connection scheme, the two parts of battery modules can independently supply power to their respective drive systems, realizing power supply decoupling, which is convenient for dynamically allocating power and power output according to requirements. Moreover, when a failure occurs in one part of the battery modules or the drive system, the other part can still continue to work, thereby improving the overall reliability of the system.

[0054] Furthermore, the inventors also found in the long-term practice process that: in the related art, in order to facilitate the management of the vehicle's electric power, the front drive motor, the rear drive motor, and related high-voltage loads are often made to work 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 relatively high platform voltage (such as 800V), and then it results in that small-power high-voltage loads such as DCDC (DC-DC Converter), high-voltage air conditioner, and PTC (Positive Temperature Coefficient thermistor) also need to use a relatively high platform voltage. Therefore, the usage cost of this part of small-power high-voltage loads is relatively high.

[0055] Therefore, in some other alternative implementations, the present application arranges that multiple battery modules included in the battery system are connected in series, and the power supply voltages of the first part of the battery modules and the second part of the battery modules are different. For example, the power supply voltage provided by the first part of the battery modules to the first drive system is 800V, and the power supply voltage provided by the second part of the battery modules to the second drive system is 400V.

[0056] 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 with no strong demand for high-power motors can reduce its platform voltage, thereby reducing the usage cost of low-power high-voltage loads.

[0057] For ease of understanding, please continue to refer to Figure 3 , which shows the structure diagram of the second electric drive system provided by the embodiments of the present application. As Figure 3 described, its battery system includes 5 series-connected battery modules. Among them, battery modules 1-5 form the first part of the battery modules; battery modules 2 and 3 form the second part of the battery modules. At this time, the input voltage of the second drive system is 2 / 5 of the input voltage of the first drive system.

[0058] Please continue to refer to Figure 4 , which shows the structure diagram of the third electric drive system provided by the embodiments of the present application. As Figure 4 shown, its battery system includes 6 series-connected battery modules. Among them, battery modules 1-6 form the first part of the battery modules; battery modules 2-5 form the second part of the battery modules. At this time, the input voltage of the second drive system is 4 / 6 of the input voltage of the first drive system.

[0059] Therefore, the above electric drive system can enable the first motor, the second motor, and related high-voltage loads to operate on different voltage platforms, so that some low-power high-voltage loads can operate on a relatively low voltage platform, thereby reducing the usage cost of low-power high-voltage loads and to a certain extent reducing the usage cost of the whole vehicle.

[0060] Furthermore, since the platform voltages between the first drive system and the second drive system can be different, the power decoupling of the first drive system and the second drive system is realized, and then in extreme working conditions (such as driving on muddy roads, sandy roads, snow-covered roads, etc.), one of the drive systems can be used to drive the vehicle.

[0061] In addition, the battery system is composed of multiple series-connected battery modules, and can adjust the voltage according to requirements, so as to facilitate meeting the voltage requirements of the drive system.

[0062] Alternatively, when multiple battery modules included in the battery system are connected in series, the power supply voltages of the first part of the battery modules and the second part of the battery modules can also be the same.

[0063] Further, in the case where multiple battery modules of the battery system are connected in series, there are shared battery modules between the first part of the battery modules and the second part of the battery modules. For example, in Figure 2 , there are shared battery module 2 and battery module 3. In this way, it is convenient to conduct overall management of multiple battery modules (such as overall management of the voltages, powers, etc. of multiple battery modules). In addition, even if a certain battery module malfunctions, a certain voltage output can be maintained through the shared battery modules, reducing the risk that any drive system cannot work due to the failure of a single battery module.

[0064] Alternatively, to achieve different power supply voltages between the first part of the battery modules and the second part of the battery modules, the first part of the battery modules and the second part of the battery modules may not share battery modules. For example, in Figure 4 , 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.

[0065] Further, 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 some 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 relatively large power demand, and the second part of the battery modules can be used in a drive system with relatively small power demand. Subsequently, it is also convenient to dynamically allocate power according to the power demand.

[0066] In some alternative implementation manners, the system further includes: a first power distribution unit, which is connected to the overall positive and negative electrodes of the first part of the battery modules 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 electrodes of the second part of the battery modules through a high - voltage cable, and is connected to the power input interface of the second drive system through another high - voltage cable.

[0067] For example, in Figure 2Among them, the positive terminal of the first power distribution unit (PDU1) is connected to the positive electrode of battery module 1 through a high-voltage cable, and the negative terminal of PDU1 is connected to the negative electrode of battery module 4 through a high-voltage cable. Moreover, 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 battery module 2 through a high-voltage cable, and the negative terminal of PDU2 is connected to the negative electrode of battery module 3 through a high-voltage cable. Moreover, PDU2 is connected to the power input interface of the second drive system through another high-voltage cable.

[0068] In this implementation, after decoupling the battery modules in the battery system into the first part of battery modules and the second part of battery modules, each part of battery modules can adaptively distribute power through the corresponding power distribution unit, so as to facilitate the realization of the purpose of dynamically distributing power.

[0069] In addition, in the related art, with the increasing demand for the charging speed and cruising range of new energy vehicles, there are more and more vehicles with high-voltage platforms on the market. And as the voltage platform increases, the safety protection requirements for the high-voltage cables for transmitting high-voltage power also increase accordingly.

[0070] Furthermore, the increase in the safety protection requirements for high-voltage cables has a greater impact on new energy vehicles including four-wheel drive systems. The specific reason is that: such new energy vehicles include a front-wheel drive system and a rear-wheel drive system. And 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 such new energy vehicles, the safety risk is often increased due to the need to use relatively long high-voltage cables.

[0071] Furthermore, currently, new energy vehicles driven by four-wheel drive on the market usually have only one charging port (i.e., DC port, direct current charging port), and this charging port can be set in the front-wheel drive system or the rear-wheel drive system. Taking the drive system shown in Figure 1 as an example, the battery system can connect the positive electrode of the first battery module 1 and the negative electrode of the last battery module 4 to PDU1 through high-voltage cables respectively, and then PDU1 can perform power distribution. Among them, PDU1 will transmit high-voltage power to PDU2 through high-voltage cables ( Figure 1 which are high-voltage cable 1 and high-voltage cable 2 in the figure), and then PDU2 distributes it to the front-wheel drive system and related high-voltage loads.

[0072] 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, relatively long high-voltage cables are needed to transmit high-voltage power from one drive system to another drive system. In this way, the risk of safety hazards due to the long high-voltage cables is relatively large, so the safety risk is increased.

[0073] In some alternative implementation manners of the present application, the battery system is configured to be disposed in the chassis area between the first drive system and the second drive system. At this time, the second drive system can be directly electrically connected to the second part of the battery modules in the battery system, and thus there is no need to transmit the high-voltage power of one drive system to the other drive system over a long distance through a high-voltage cable.

[0074] For specific reference, please refer to Figure 2 Compared with Figure 1 the structure shown, in this implementation manner, the high-voltage cable between the two drive systems is cancelled, and high-voltage cables (such as Figure 2 the high-voltage cable 1-1 and the high-voltage cable 1-2 in ) between the second drive system and the second part of the battery modules are added. Since the high-voltage cables between the second drive system and the second part of the battery modules are relatively short, the safety risk and the usage cost can be reduced.

[0075] Therefore, compared with the wiring structure shown in Figure 1 , in this implementation manner, the usage length of the high-voltage cable is shortened, the safety risk is reduced, and the usage cost of the high-voltage cable is also reduced.

[0076] It should be noted that in this implementation manner, the PDU is located between the battery system and the drive system. For example, in Figure 2 , 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.

[0077] In some alternative implementation manners, the battery system is configured such that the distance between the overall positive and negative electrodes of the first part of the battery modules and the first power distribution unit is less than the distance between the overall positive and negative electrodes of the first part of the battery modules and the second power distribution unit; the distance between the overall positive and negative electrodes of the second part of the battery modules and the second power distribution unit is less than the distance between the overall positive and negative electrodes of the second part of the battery modules and the first power distribution unit.

[0078] That is to say, the overall positive and negative electrodes of the first part of the battery modules in the battery system approach the first power distribution unit side, while the overall positive and negative electrodes of the second part of the battery modules approach the second power distribution unit side, which can further shorten the usage length of the high-voltage cable.

[0079] In some alternative implementation manners, the distance between the second drive system and the overall positive and negative electrodes of the second part of the battery modules is not greater than 0.5 meters.

[0080] It should be noted that the distance between the front drive system and the rear drive system in the related art is approximately 2 meters, and the distances between the battery system and each of them are approximately 0.5 meters. Therefore, in some embodiments of the present application, the high-voltage cable with a length of approximately 2 meters can be reduced to approximately 0.5 meters, thereby significantly shortening the length of the high-voltage cable used. Moreover, if the distances between the battery system and the two are shorter, the length of the high-voltage cable used 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 position setting of the drive system, and the distance between the PDU and the drive system. However, no matter how it 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.

[0081] In some alternative implementation manners, the first drive system is a rear drive system, and the second drive system is a front drive system. In this way, power decoupling between the front drive system and the rear drive system can be achieved.

[0082] In some other alternative implementation manners, the electric drive system further includes: a third drive system for driving the third motor of the vehicle; a fourth drive system for driving the fourth motor of the vehicle; the third part of the battery modules of the battery system is electrically connected to the third drive system for supplying power to the third drive system, and the fourth part of the battery modules of the battery system is electrically connected to the fourth drive system for supplying power to the fourth drive system.

[0083] 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 respectively driven by the first drive system and the second drive system, and the left rear wheel and the right rear wheel are respectively driven by the third drive system and the fourth drive system, thereby driving the four wheels to move.

[0084] 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 can be similar to the corresponding processes of the first drive system and the second drive system in the foregoing, and will not be elaborated here.

[0085] In this implementation manner, one wheel can be driven by one drive system, so that multiple drive systems can drive multiple wheels. In this way, power decoupling between multiple drive systems can be achieved, which is convenient for dynamically allocating power sources to multiple drive systems.

[0086] In addition, it should be clear that, in order for each part of the battery modules to supply power to their respective corresponding drive systems normally, there is no short circuit or open circuit in each part of the battery modules, and there is no short circuit or open circuit in the connection between each part of the battery modules and their respective corresponding drive systems. For example, in Figure 2In this case, the second drive 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 situation.

[0087] In addition, in order to meet the wiring structure of the high - voltage cables in various implementation manners of this application, the number N of battery modules in the above - mentioned battery system can meet the condition: and the number M of battery modules in the second part of battery modules needs to meet the condition: .

[0088] In some application scenarios, if multiple battery modules included in the battery system are connected in series, the power supply voltages of the first part of battery modules and the second part of battery modules are different. Moreover, if there are shared battery modules between the first part of battery modules and the second part of battery modules, since each part of battery modules supplies power to different drive systems respectively, this may cause the voltage between the first part of battery modules and the second part of battery modules in the battery system to be inconsistent, and then may shorten the driving range of the vehicle.

[0089] For example, in Figure 2 , 4 battery modules can discharge to the first drive system together. When battery modules 2 and 3 discharge to the first drive system, they can also discharge to the second drive system. Therefore, within the same discharge time, the voltages of battery modules 2 and 3 are lower than those of battery modules 1 and 4. During the charging - back process, when battery modules 2 and 3 are charged back through the first drive system, they can also be charged back through the second drive system. Therefore, within the same charging - back time, the voltages of battery modules 2 and 3 are higher than those of battery modules 1 and 4. Therefore, there may be a problem of voltage inconsistency between the multiple battery modules in the second part of battery modules and the battery modules in the first part of battery modules.

[0090] Furthermore, due to the problem of voltage inconsistency between the first part of battery modules and the second part of battery modules, in order to reduce the risk of over - discharge or over - charge of the battery modules, the discharge process and the charging - back process will be restricted, and then the driving range of the vehicle will be shortened.

[0091] To improve this situation, the inventor considered that since the multiple battery modules in the battery system are connected in series, for the same part of battery modules, the current flowing through multiple battery modules therein is the same. Therefore, the voltage difference between the first part of battery modules and the second part of battery modules can be reduced through power control.

[0092] Further, taking the case where the voltage of the first part of the battery module is higher than that of the second part of the battery module as an example, on the one hand, the driving power provided by the first driving system to the outside can be increased, thereby reducing the voltage of the first part of the battery module; on the other hand, the driving power provided by the second driving system to the outside can be reduced, thereby increasing the voltage of the second part of the battery module. Therefore, through the above two aspects, the voltage difference between the first part of the battery module and the second part of the battery module can be narrowed.

[0093] It should be noted that during the discharging process and the charging process of the battery system, electrical energy exchange will occur with the corresponding driving system. Therefore, corresponding control methods can be implemented by the controller respectively during the discharging process and the charging process.

[0094] In some application scenarios, the above-mentioned controller can be, for example, the VCU (Vehicle Control Unit) of the vehicle or the power domain controller, or it can also be other separate controllers, and the present application does not limit this.

[0095] Please refer to Figure 5 , which shows a flowchart of a control method executed by a controller provided in an embodiment of the present application. As Figure 5 shown, the controller can execute the following step 501 and / or step 502.

[0096] Step 501, during the discharging process of the battery system, according to the driving power demand, control the first driving system and / or the second driving system to provide driving power to narrow the voltage difference between the first part of the battery module and the second part of the battery module;

[0097] The above driving power demand can be used to represent the driving power that the driving system as a whole needs to provide to the outside.

[0098] It should be noted that when the driving system provides driving power to the outside, electrical energy can be provided from the first part of the battery module to the first driving system to enable the first driving system to provide driving power to the outside. Electrical energy can also be provided from the second part of the battery module to the second driving system to enable the second driving system to provide driving power to the outside, or the first driving system and the second driving system can provide driving power to the outside together.

[0099] Taking Figure 2Taking the shown structure as an example, during the discharge process of the battery system, the voltage of the first part of the battery modules is greater than that of the second part of the battery modules. To narrow the voltage difference between the two, the driving power provided by the two driving systems can be controlled. Here, to determine whether the voltage of the first part of the battery modules is greater than that of the second part of the battery modules, for example, it can be determined by measuring the battery modules of each part through a voltage sensor, or obtained by estimating the SOC corresponding to the battery modules of each part.

[0100] Specifically, if the driving power demand is large, the first driving system can be controlled to provide driving power preferentially. 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. Additionally, 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 outward, thereby reducing the voltage of the first part of the battery modules. Or, the second driving system can be made to provide less driving power outward, thereby increasing the voltage of the second part of the battery modules. In this way, the voltage difference between the first part of the battery modules and the second part of the battery modules can be narrowed.

[0101] Step 502, during the recharge process of the battery system, according to the recharge power demand of the battery system, control the braking power of the first driving system and / or the second driving system to narrow the voltage difference between the first part of the battery modules and the second part of the battery modules.

[0102] In the regenerative braking of new energy vehicles, when the vehicle decelerates or brakes, the 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-mentioned braking power can be understood, for example, as the energy rate recovered by the driving system from the vehicle movement, that is, the electrical energy that can be converted and stored per unit time.

[0103] In some application scenarios, if the recharge power demand is large, the second driving system can be controlled to recharge preferentially to convert the kinetic energy obtained from the vehicle rotation process into electrical energy and recharge it to the second part of the battery modules. When the braking power of the second driving system is insufficient to meet the recharge power demand, the first driving system is coordinated to recharge together. Additionally, if the recharge power demand is small, only the second driving system can be controlled to recharge.

[0104] In this way, the braking power of the second driving system can be increased, thereby increasing the voltage of the second part of the battery modules. And, the braking power of the first driving system can be reduced, thereby reducing the voltage of the first part of the battery modules. Therefore, the voltage difference between the first part of the battery modules and the second part of the battery modules can be narrowed.

[0105] 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 respectively during the discharging and / or recharge process of the battery system, the voltage inconsistency between the first part of the battery modules and the second part of the battery modules can be improved during different processes, thereby increasing the driving range of the vehicle.

[0106] In some alternative implementation manners, refer to Figure 6 , if the first driving system is a rear-wheel drive system and the second driving system is a front-wheel drive system, then controlling the first driving system and / or the second driving system to provide driving power according to the driving power requirement in step 501 above includes:

[0107] Sub-step 5011, if the driving power requirement is not greater than the first driving power of the first driving system, then provide driving power through the first driving system;

[0108] Sub-step 5012, if the driving power requirement is greater than the first driving power of the first driving system, then provide driving power through the first driving system and the second driving system.

[0109] The above first driving power can be, for example, the maximum allowable power that the first driving system can provide during driving, or a larger allowable power approaching the maximum allowable power. In this way, if the driving power requirement 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 requirement, and then it can be provided only by the first driving system, thereby reducing the voltage of the first part of the battery modules. When the driving power requirement is greater than the first driving power, it means that the driving power provided by the first driving system cannot meet the driving power requirement, and then the two driving systems can be controlled to provide together to meet the driving power requirement.

[0110] In this implementation manner, the first driving system can be adaptively used to provide driving power, or used together with the second driving system to provide driving power according to the magnitude relationship between the driving power requirement and the first driving power. In this way, both the driving power requirement and the voltage inconsistency can be taken into account, so that on the basis of meeting the driving power requirement, the voltage difference between the first part of the battery modules and the second part of the battery modules can be reduced.

[0111] In some alternative implementation manners, controlling the first driving system and / or the second driving system to provide driving power according to the driving power requirement in step 501 above further includes:

[0112] Step 1, determine the first SOC according to the first current flowing through the first part of the battery modules;

[0113] The above-mentioned first current can be, for example, any one of I1 in the drive system as shown in Figures 2 - 4 . In some application scenarios, the controller can, for example, look up the current-SOC relationship table to obtain the first SOC corresponding to the first current.

[0114] Step 2: Determine the second SOC according to the second current flowing through the second part of the battery module and the first current;

[0115] The above-mentioned second current can be, for example, any one of I2 in the drive system as shown in Figures 2 - 4 .

[0116] It should be noted that during the discharge process, in addition to discharging to the first drive system, the second part of the battery module may also discharge to the second drive system. At this time, the total discharge current of the second part of the battery module is the sum of the first current and the second current. Therefore, the above-mentioned second SOC is the SOC corresponding to the sum of the above currents.

[0117] Furthermore, the controller can also, for example, look up the current-SOC relationship table to obtain the above-mentioned second SOC.

[0118] It should be understood that there are multiple implementation methods for calculating the SOC according to the current, such as the ampere-hour integration method and the open-circuit voltage method. Moreover, when calculating the SOC, parameters such as the initial SOC, current integration time, and temperature compensation can also be combined. The embodiments of the present application will not elaborate on this.

[0119] Step 3: Determine the first allowable current flowing through the first drive system according to the smaller value of the first SOC and the second SOC;

[0120] The above-mentioned first allowable current is also the current allowed to flow through the first drive system.

[0121] It should be noted that in order to reduce the risk of over-discharge of the first part of the battery module or the second part of the battery module, the controller can determine the above-mentioned first allowable current according to the smaller value of the first SOC and the second SOC. In some application scenarios, for example, the current corresponding to the smaller SOC can also be queried in the current-SOC relationship table and determined as the first allowable current.

[0122] Step 4: Determine the first drive power of the first drive system according to the first allowable current and the voltage of the first drive system.

[0123] In this way, the above-mentioned first driving power is the maximum driving power that the first driving system can provide when the over-discharge risk is relatively low. Subsequently, when controlling the driving powers of the first driving system and the second driving system based on the magnitude relationship between the maximum driving power and the driving power demand, the first driving system can be utilized to the greatest extent, so as to improve the voltage inconsistency between the first part of the battery modules and the second part of the battery modules while reducing the risk of over-discharge of the second part of the battery modules.

[0124] Furthermore, in this implementation manner, the first driving power is determined by the SOC value. Since the SOC value can more accurately reflect the current available energy level of some battery modules, a more accurate first driving power can be obtained.

[0125] It should be noted that, in addition to determining the first driving power using the SOC, for example, the first driving power can also be determined using the voltage of some battery modules. Those skilled in the art can select according to the actual situation, and this application does not limit this.

[0126] In this way, the step of, if the driving power demand is greater than the first driving power of the first driving system, providing driving power through the first driving system and the second driving system described in the above sub-step 5012 includes:

[0127] First, if the driving power demand is greater than the first driving power of the first driving system, the remaining driving power demand is determined according to the driving power demand and the first driving power.

[0128] For example, the controller can subtract the power value P corresponding to the driving power demand from the first driving power P1, so as to obtain the power value P2 corresponding to the remaining driving power demand.

[0129] Then, according to the remaining driving power demand and the voltage of the second driving system, the current supplied to the second driving system is determined.

[0130] For example, the controller can divide the power value P2 corresponding to the remaining driving power demand by the voltage U2 of the second driving system, so as to obtain the current I'2 supplied to the second driving system (that is, I2 = P2 / U2).

[0131] Then, according to the maximum allowable output current of the second driving system and the first current flowing through the first driving system, the allowable current supplied to the second driving system is determined.

[0132] For example, the controller can subtract the first current I1 from the maximum allowable discharge current I3, so as to obtain the allowable current supplied to the second driving system.

[0133] Then, determine the smaller value between the current supplied to the second drive system and the allowable current as the target allowable current for supplying the second drive system; for example, after obtaining the difference between I3 and I1, determine the smaller value between this difference and I'2 as the target allowable current.

[0134] Finally, control the second drive system to provide drive power according to the target allowable current.

[0135] In this implementation manner, when the first drive power of the first drive system is insufficient to meet the drive power requirement, the second drive system is controlled to provide drive power to meet the drive power requirement. This can improve the voltage inconsistency between the first part of the battery modules and the second part of the battery modules while meeting the drive power requirement. Moreover, since the target allowable current is the smaller value between the current determined to be supplied to the second drive system and the allowable current, after supplying the target allowable current to the second drive system, the risk of over-discharge of the second part of the battery modules can be reduced.

[0136] During the recharge process of the battery system, due to the voltage difference between the first part of the battery modules and the second part of the battery modules, there may be a difference in the SOC between the battery modules. Therefore, the recharge can be performed based on the magnitude relationship between the SOC of the first part of the battery modules and the SOC of the second part of the battery modules.

[0137] In some alternative implementation manners, refer to Figure 7 ., if the first drive system is a rear-wheel drive system and the second drive system is a front-wheel drive system, then the controlling the first drive system and / or the second drive system to provide braking power according to the recharge power requirement of the battery system in step 502 includes:

[0138] Step 5021, determine 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;

[0139] Here, the process of determining the first SOC and the second SOC can be the same as or similar to the corresponding part in the previous text, and will not be elaborated here.

[0140] Step 5022, if the second SOC is less than the first SOC, increase the braking power of the second drive system when the recharge power requirement is not greater than the second recharge allowable power corresponding to the second drive system;

[0141] Step 5023, if the second SOC is less than the first SOC, increase the braking power of the first drive system when the recharge power requirement is greater than the second recharge allowable power corresponding to the second drive system;

[0142] The above second recharge allowable power can be, for example, the maximum braking power allowed for the second drive system during the recharge process, or a larger braking power approaching the maximum braking power.

[0143] It should be noted that if the second SOC is less than the first SOC, it indicates that during the power exchange process, the voltage between the first part of the battery modules and the second part of the battery modules is inconsistent, and the voltage of the second part of the battery modules is lower than that of the first part of the battery modules. Therefore, the magnitude relationship between the recharge power demand and the second recharge allowable power corresponding to the second drive system can be further determined to determine whether controlling the second drive system to recharge can meet the recharge power demand.

[0144] Among them, if the recharge power demand is not greater than the second recharge allowable power, it means that the second drive system can meet the recharge power demand by recharging, and then it can be carried out only by the second drive system to increase the voltage of the second part of the battery modules. At this time, for example, the second recharge allowable power corresponding to the second drive system can be divided by its voltage to obtain the corresponding recharge allowable current to recharge the second drive system.

[0145] In addition, when the recharge power demand is greater than the second recharge allowable power, it means that the second drive system cannot meet the recharge power demand by recharging. Since the platform voltage of the first drive system is relatively high, recharging through the first drive system can meet the recharge power demand faster. Therefore, only the first drive system can be controlled to recharge. Further, the controller can also control the two drive systems to recharge together to balance meeting the recharge power demand and increasing the voltage of the second part of the battery modules.

[0146] Step 5024, if the second SOC is not less than the first SOC, increase the braking power of the first drive system. Here, when the second SOC is not less than the first SOC, if the first drive system is a rear-wheel drive system, the recharge efficiency can be improved by controlling the first drive system to recharge.

[0147] In this implementation, the first drive system or the second drive system is adaptively controlled to recharge based on the magnitude relationship between the first SOC and the second SOC, which improves the control accuracy to a certain extent. In addition, during the recharge process, the recharge efficiency of the first drive system and the second drive system can be balanced, which also improves the vehicle's cruising range to a certain extent.

[0148] Please continue to refer to Figure 7 , after controlling the first drive system to provide braking power, the step of controlling the braking power of the first drive system and / or the second drive system according to the recharge power demand of the battery system in step 502 further includes:

[0149] Step 5025: Determine the first recharge allowable current corresponding to the first drive system according to the larger one of the first SOC and the second SOC.

[0150] Here, the controller can also look up the current - SOC relationship table, for example, to obtain the above - mentioned first recharge allowable current.

[0151] It should be noted that since the current battery system is in the recharge process, different from its discharge process, currently, in order to reduce the overcharge risk of the second part of the battery module, the allowable current supplied to the first drive system is determined according to the larger one of the first SOC and the second SOC, and this allowable current is the above - mentioned first recharge allowable current.

[0152] Step 5026: Determine the second recharge allowable current corresponding to the second drive system according to the second SOC.

[0153] In some application scenarios, the controller can also look up the current - SOC relationship table, for example, to obtain the second recharge allowable current corresponding to the second SOC.

[0154] Step 5027: 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.

[0155] Among them, when the above - mentioned current difference is greater than 0, the second recharge allowable current is greater than the first recharge allowable current, then there is an overcharge risk for the second part of the battery module. Therefore, by continuing to recharge through this current difference, the second recharge allowable current can be made not greater than the first recharge allowable current, thereby reducing the overcharge risk of the second part of the battery module.

[0156] In some optional implementation manners, after controlling the first drive system to provide braking power, in step 502, controlling the braking power of the first drive system and / or the second drive system according to the recharge power demand of the battery system further includes:

[0157] 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;

[0158] If the current recharge power demand is not greater than the first recharge allowable power, re - determine the first SOC and the second SOC to re - control the braking power of the first drive system and / or the second drive system.

[0159] In this implementation manner, the second recharge allowable current can be made not greater than the first recharge allowable current, so as to reduce the risk of overcharging the second part of the battery module.

[0160] In some optional implementation manners, if fast charging is performed on the battery system, the larger value of the first SOC and the second SOC can be determined, and the current corresponding to the larger value can be determined as the fast charging current to charge the battery system. And charging can be stopped when the first SOC is greater than or equal to 100%, or when the second SOC is greater than or equal to 100%, so as to protect the battery.

[0161] Those skilled in the art can understand that in the above method of the specific embodiment, the writing order of each step does not mean a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of each step should be determined according to its function and possible internal logic.

[0162] Based on the same inventive concept, an embodiment of the present application provides a vehicle, and the vehicle includes the electric drive system in any of the above implementation manners.

[0163] 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 only illustrative. For example, the division of the units is only a logical function division, and there may be other division methods in actual implementation. For another example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point, the displayed or discussed coupling or direct coupling or communication connection between each other can be through some communication interfaces. The indirect coupling or communication connection of the system or unit can be in an electrical, mechanical or other form.

[0164] In addition, the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0165] Furthermore, in each embodiment of the present application, the various functional modules can be integrated together to form an independent part, or each module can exist alone, or two or more modules can be integrated to form an independent part.

[0166] In this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0167] The above are only the embodiments of the present application and are not intended to limit the protection scope of the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. An electric drive system, characterized in that, Comprising: A first drive system for driving a first part of the wheels of the vehicle; A second drive system for driving a second part of the wheels of the vehicle; A battery system including a plurality of battery modules, a first part 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 being electrically connected to the second drive system for supplying power to the second drive system; The first part of the battery modules being connected in parallel with the second part of the battery modules; Or, The plurality of battery modules included in the battery system are connected in series, and the supply voltages of the first part of the battery modules and the second part of the battery modules are different; there are common battery modules between the first part of the battery modules and the second part of the battery modules; The electric drive system further includes a controller for: During the discharge process of the battery system, according to the drive power demand, controlling the first drive system and / or the second drive system to provide drive power to reduce the voltage difference between the first part of the battery modules and the second part of the battery modules; Wherein, 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 drive power demand is greater than the first drive power of the first drive system, provide drive power through the first drive system and the second drive system; Wherein, if the drive power demand is greater than the first drive power of the first drive system, determine the remaining drive power demand according to the drive power demand and the first drive power; Determine the current supplied to the second drive system according to the remaining drive power demand and the voltage of the second drive system; Determine the allowable current supplied to the second drive system according to the maximum allowable output current of the second drive system and the first current flowing through the first drive system; Determine the smaller of the current supplied to the second drive system and the allowable current as the target allowable current supplied to the second drive system; Control the second drive system to provide drive power according to the target allowable current.

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

5. The electric drive system according to any one of claims 1-4, 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 1-4, characterized in that, It further includes: A third drive system for driving the third part of the vehicle's wheels; A fourth drive system for driving the fourth part of the vehicle's wheels; The third part of the battery module of the battery system is electrically connected to the third drive system to supply power to the third drive system, and the fourth part of the battery module of the battery system is electrically connected to the fourth drive system to supply power to the fourth drive system.

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

8. The electric drive system according to claim 1, wherein If the first drive system is a rear-wheel drive system and the second drive system is a front-wheel drive system, then the controller is further configured to: If the drive power demand is not greater than the first drive power of the first drive system, provide drive power through the first drive system.

9. The electric drive system according to claim 8, characterized in that, The controller is further configured to: Determine the first SOC according to the first current flowing through the first part of the battery module; Determine the second SOC according to the second current flowing through the second part of the battery module and the first current; Determine the first allowable current flowing through the first drive system according to the smaller value of the first SOC and the second SOC; Determine the first drive power of the first drive system according to the first allowable current and the voltage of the first drive system.

10. The electric drive system according to any one of claims 1-4 or 7, characterized in that The electric drive system further includes a controller, and the controller is configured to: During the charging process of the battery system, control the braking power of the first drive system and / or the second drive system according to the charging power demand 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.

11. The electric drive system according to claim 10, 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, then the controller is further configured 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, increase the braking power of the second drive system when the charging power demand is not greater than the second allowable charging power corresponding to the second drive system; If the second SOC is less than the first SOC, increase the braking power of the first drive system when the charging power demand is greater than the second allowable charging power corresponding to the second drive system; If the second SOC is not less than the first SOC, increase the braking power of the first drive system.

12. The electric drive system according to claim 11, characterized in that, The controller is further configured to: after controlling the first drive system to provide braking power, determine the first allowable charging current corresponding to the first drive system according to the larger value of the first SOC and the second SOC; Determine a 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.

13. The electric drive system according to claim 12, characterized in that, The controller is further configured 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, and 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, re-determine the first SOC and the second SOC to re-control the braking power of the first drive system and / or the second drive system.

14. A control method for an electric drive system, characterized in that, Applied to the electric drive system according to any one of claims 1-7, the method includes: 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 part of the battery modules and the second part of the battery modules; Wherein, if the first drive system is a rear-wheel drive system and the second drive system is a front-wheel drive system, the following steps are performed: If the drive power demand is greater than the first drive power of the first drive system, provide drive power through the first drive system and the second drive system; Wherein, if the drive power demand is greater than the first drive power of the first drive system, determine the remaining drive power demand according to the drive power demand and the first drive power; Determine the current supplied to the second drive system according to the remaining drive power demand and the voltage of the second drive system; Determine the allowable current supplied to the second drive system according to the maximum allowable output current of the second drive system and the first current flowing through the first drive system; Determine the smaller of the current supplied to the second drive system and the allowable current as the target allowable current supplied to the second drive system; Control the second drive system to provide drive power according to the target allowable current; And / or During the recharge process of the battery system, according to the recharge power demand 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 part of the battery modules and the second part of the battery modules.

15. A vehicle, characterized in that, Comprising: The electric drive system according to any one of claims 1-13.

Images