Battery system, and charging and discharging control method for battery system

Abstract

Disclosed in the present application are a battery system, and a charging and discharging control method for a battery system. The battery system comprises: a vehicle controller, an on-board charger and an alternating current-to-direct current conversion assembly, wherein the vehicle controller is connected to the alternating current-to-direct current conversion assembly and a range-extended battery, is connected to the on-board charger, and is configured to control the charging and discharging of the range-extended battery on the basis of a required driving power of a driving mechanism of a vehicle, charging efficiency corresponding to the on-board charger, and discharging efficiency corresponding to the alternating current-to-direct current conversion assembly; the on-board charger is connected to the alternating current-to-direct current conversion assembly, and is configured to convert into a direct current an alternating current converted and outputted by the alternating current-to-direct current conversion assembly, and to supply power to the driving mechanism; and the alternating current-to-direct current conversion assembly is connected to the range-extended battery, and is configured to convert into an alternating current the direct current outputted by the range-extended battery.

Description

Battery systems and battery system charging and discharging control methods Cross-reference to related applications

[0001] This application claims priority to Chinese Patent Application No. 202411485336.1, filed on October 23, 2024, entitled “Battery System and Method for Charging and Discharging Control of Battery System”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery management technology, and in particular to a battery system and a method for controlling the charging and discharging of the battery system. Background Technology

[0003] In related technologies, increasing a vehicle's driving range is typically achieved by adding range-extending batteries. Therefore, improving the energy utilization efficiency of range-extending batteries is crucial for extending a vehicle's driving range. Summary of the Invention

[0004] This application provides a battery system and a charging and discharging control method for the battery system, which can improve the energy utilization rate of the range extender battery and provide a basis for increasing the vehicle's driving range.

[0005] In a first aspect, this application provides a battery system comprising: a vehicle controller, an on-board charger, and an AC / DC converter; the vehicle controller, connected to the AC / DC converter and the range extender battery, and connected to the on-board charger, is configured to control the charging and discharging of the range extender battery according to the required drive power of the vehicle's drive mechanism, the charging efficiency of the on-board charger, and the discharging efficiency of the AC / DC converter; the on-board charger, connected to the AC / DC converter, is configured to convert the AC power output by the AC / DC converter into DC power and supply power to the drive mechanism; the AC / DC converter, connected to the range extender battery, is configured to convert the DC power output by the range extender battery into AC power.

[0006] Within a high power range for charge and discharge efficiency, the range extender battery exhibits high charge and discharge efficiency, resulting in higher energy utilization. In this application, the charge and discharge of the range extender battery requires the participation of an AC / DC converter and an on-board charger. The charge and discharge efficiencies of the AC / DC converter and the on-board charger also affect the charge and discharge efficiency of the range extender battery. Therefore, in this application, the discharge power range of the range extender battery is determined by the discharge efficiency of the AC / DC converter and the charging efficiency of the on-board charger. Within this discharge power range, the AC / DC converter and the on-board charger operate at higher efficiency levels, enabling the range extender battery to also have higher discharge efficiency, thereby improving the energy utilization of the range extender battery.

[0007] Therefore, it is evident that the solution provided in this application can improve the energy utilization rate of the range extender battery, thus providing a foundation for increasing the vehicle's driving range.

[0008] In some embodiments, the AC power converted by the AC / DC conversion component is single-phase AC power or three-phase AC power, realizing the AC connection between the range extender battery and the vehicle, thereby adapting to vehicles with different types of AC interfaces.

[0009] In some embodiments, the AC / DC conversion assembly includes a first DC interface, a first AC interface, and a first conversion component; the first DC interface is connected to the range extender battery; the first AC interface is connected to a second AC interface of the on-board charger; and the first conversion component is connected between the first DC interface and the first AC interface.

[0010] The range extender battery's DC output is converted to AC by an AC-DC converter, and the on-board charger's AC output is converted to AC by an AC-DC converter, thus enabling AC connection between the range extender battery and the vehicle, thereby increasing the driving range of electric vehicles with AC interfaces.

[0011] In some embodiments, the on-board charger includes a second AC interface, a second DC interface, and a second conversion component; the second AC interface is connected to an AC charging device via an AC charging interface and to a range extender battery; the second DC interface is connected to a DC charging device via a DC charging interface and to a power battery and an on-board high-voltage device; the second conversion component is connected between the second AC interface and the first DC interface.

[0012] By installing an on-board charger to connect the vehicle and the range extender battery, the range extender battery can be used to provide power to the main battery, increasing the vehicle's range. At the same time, it can also realize the transfer of AC power between the range extender battery and the vehicle, improving the flexibility of vehicle charging and discharging.

[0013] In some embodiments, the battery system further includes: a DC-DC converter connected to a second DC interface and a vehicle controller, configured to convert the DC power output from the on-board charger to power the vehicle controller; and a low-voltage power distribution system connected to the DC-DC converter and configured to power the vehicle's on-board low-voltage equipment.

[0014] By setting up DC-DC conversion components and a low-voltage power distribution system, power is supplied to the vehicle's onboard low-voltage equipment after the vehicle is powered on at low voltage.

[0015] In some embodiments, the battery system further includes: a motor controller; a first terminal of the motor controller is connected to a drive mechanism, a second terminal of the motor controller is connected to an on-board charger and a DC charging device, and a control terminal of the motor controller is connected to the signal output terminal of the vehicle controller; the motor controller is configured to control the operation of the drive mechanism according to the output signal of the vehicle controller.

[0016] By setting up a motor controller and communicating with the vehicle controller, the vehicle controller can determine the strategy for providing power to the drive mechanism based on the drive power required by the drive mechanism, as well as the power battery, range extender battery capacity, output power, and power efficiency. This will improve energy utilization and reduce energy waste while ensuring the normal operation of the drive mechanism.

[0017] In some embodiments, the vehicle controller connects to the on-board charger and range extender battery via the vehicle controller local area network bus (CAN), thereby eliminating the need for an additional bus for the range extender battery and reducing costs.

[0018] In some embodiments, the vehicle controller is connected to the on-board charger via the vehicle controller local area network bus CAN, and to the range extender battery via the range extender CAN.

[0019] The range extender battery and the on-board charger use different buses to connect to the vehicle controller, which reduces the data transmission complexity of using the same bus to transmit data, thereby reducing the risk of data mistransmission and omission, and improving the stability and reliability of data transmission.

[0020] In some embodiments, the vehicle controller is configured to drive the range extender battery to charge and discharge within a target discharge power range according to the needs of the vehicle's drive mechanism, wherein the target discharge power range is a power range determined by the charging efficiency of the on-board charger and the discharge efficiency of the AC / DC conversion component.

[0021] The discharge power range of the range extender battery is determined by the discharge efficiency of the AC / DC conversion component and the charging efficiency of the on-board charger. Within this discharge power range, the AC / DC conversion component and the on-board charger operate at a higher efficiency range, which enables the range extender battery to also have a higher discharge efficiency, thereby improving the energy utilization rate of the range extender battery.

[0022] In some embodiments, the vehicle controller is further configured to acquire first charging efficiency data corresponding to the on-board charger and second discharging efficiency data corresponding to the AC / DC conversion component, and determine the discharge power range corresponding to the range extender battery based on the first charging efficiency data and the second discharging efficiency data.

[0023] The discharge power range of the range extender battery is determined by the discharge efficiency of the AC / DC conversion component and the charging efficiency of the on-board charger, so that the range extender battery can discharge within a higher efficiency discharge power range, thereby improving the discharge efficiency of the range extender battery.

[0024] In some embodiments, the vehicle controller is further configured to calculate the product of the first charging efficiency data and the second discharging efficiency data to obtain the initial discharge efficiency range corresponding to the range extender battery; determine the discharge efficiency range from the initial discharge efficiency range where the discharge efficiency of the range extender battery is higher than the preset discharge efficiency; and determine the discharge power range corresponding to the discharge efficiency range based on the preset correlation between discharge efficiency and discharge power.

[0025] The discharge power range of the range extender battery is determined by using the first charging efficiency data corresponding to the on-board charger and the second discharge efficiency data corresponding to the AC / DC conversion component. Within this discharge power range, the AC / DC conversion component and the on-board charger operate in a higher efficiency range, which enables the range extender battery to also have a higher discharge efficiency, thereby improving the energy utilization rate of the range extender battery.

[0026] In some embodiments, the vehicle controller is further configured to determine the target output power of the range extender battery in the following manner: when the required drive power is less than a first discharge power, the target output power of the range extender battery is determined to be 0, and the power battery is controlled to provide the required drive power to the drive mechanism, wherein the first discharge power is the lower limit of the discharge power range; when the required drive power is greater than or equal to the first discharge power and less than or equal to a second discharge power, the target output power of the range extender battery is determined to be the required drive power, and the range extender battery is controlled to provide the required drive power to the drive mechanism at the target output power, wherein the second discharge power is the upper limit of the discharge power range; when the required drive power is greater than the second discharge power, the target output power of the range extender battery is determined to be the second discharge power, and the range extender battery and the power battery are controlled to simultaneously provide the required drive power to the drive mechanism, wherein the sum of the target output power provided by the range extender battery and the output power provided by the power battery is the required drive power.

[0027] Discharging the range-extending battery within a discharge power range with higher discharge efficiency can improve the discharge efficiency of the range-extending battery, thereby improving the energy utilization rate of the range-extending battery.

[0028] In some embodiments, the vehicle controller is further configured to, when the battery system is in a charging state, acquire the maximum output power of the charging device and the charging device type of the charging device; and determine the target charging power of the charging device for charging the range-extending battery based on the maximum output power of the charging device and the charging strategy corresponding to the charging device type.

[0029] Different charging strategies are employed to charge the range-extender battery based on the type of charging equipment, thereby improving its charging efficiency. Furthermore, the maximum output power of the charging equipment is considered during the charging process, ensuring that, under suitable conditions, the maximum output power of the charging equipment can be used to charge the range-extender battery, further enhancing its charging efficiency.

[0030] In some embodiments, when the charging device is a DC charging device, the vehicle controller determines the target charging power for the range extender battery by the charging device in the following manner: when the maximum output power of the charging device is less than or equal to the maximum charging power corresponding to the power battery, the target charging power is determined to be 0, and the DC charging device is controlled to charge the power battery; when the maximum output power of the charging device is greater than the maximum charging power corresponding to the power battery, the difference between the maximum output power of the charging device and the maximum charging power corresponding to the power battery is calculated to obtain the charging power difference; based on the charging power difference and the charging power range corresponding to the range extender battery, the target charging power for the range extender battery is determined.

[0031] When the maximum output power of the DC charging equipment cannot meet the charging needs of the power battery, the power battery should be charged first to ensure the normal operation of the vehicle. When the maximum output power of the DC charging equipment can meet the charging needs of the power battery, the range extender battery should be charged according to its charging power range to improve the charging efficiency of the range extender battery.

[0032] In some embodiments, the vehicle controller is further configured to determine the target charging power for charging the range extender battery by the charging device in the following manner: if the charging power difference is less than a first charging power, the target charging power is determined to be 0, wherein the first charging power is the lower limit of the charging power range; if the charging power difference is greater than or equal to the first charging power and less than or equal to a second charging power, the target charging power is determined to be the charging power difference, wherein the second charging power is the upper limit of the charging power range; if the charging power difference is greater than the second charging power, the target charging power is determined to be the second charging power.

[0033] When the maximum output power of the DC charging equipment can meet the charging needs of the power battery, the range extender battery can be charged by combining the charging power range of the range extender battery. This ensures safe charging of the range extender battery while also improving its charging efficiency.

[0034] In some embodiments, the vehicle controller is further configured to acquire first discharge efficiency data corresponding to the on-board charger and second charging efficiency data corresponding to the AC / DC conversion component; calculate the product of the first discharge efficiency data and the second charging efficiency data to obtain an initial charging efficiency range corresponding to the range extender battery; determine the charging efficiency range from the initial charging efficiency range where the charging efficiency of the range extender battery is higher than a preset charging efficiency; and determine the charging power range corresponding to the charging efficiency range based on a preset correlation between charging efficiency and charging power.

[0035] The charging power range of the range extender battery is determined by using the first discharge efficiency data corresponding to the on-board charger and the second charging efficiency data corresponding to the AC / DC conversion component. Within this charging power range, the AC / DC conversion component and the on-board charger operate in a higher efficiency range, which enables the range extender battery to also have a higher charging efficiency, thereby improving the charging efficiency of the range extender battery.

[0036] In some embodiments, when the charging device is an AC charging device, the vehicle controller determines the target charging power for the range extender battery by the charging device in the following manner: acquiring a third charging power and a fourth charging power, wherein the third charging power is the maximum charging power corresponding to the on-board charger, and the fourth charging power is the maximum charging power corresponding to the AC / DC conversion component; if the maximum output power of the charging device is less than the third charging power, the target charging power is determined to be 0, and the on-board charger is controlled to charge the power battery at the maximum output power of the charging device; if the maximum output power of the charging device is greater than or equal to the third charging power, and less than or equal to the fifth charging power, the target charging power is determined to be a sixth charging power, wherein the fifth charging power is the sum of the third and fourth charging power, and the sixth charging power is the difference between the maximum output power of the charging device and the third charging power; if the maximum output power of the charging device is greater than the fifth charging power, the target charging power is determined to be the fourth charging power.

[0037] When the maximum output power of the AC charging equipment cannot meet the charging needs of the power battery, the power battery is charged first to ensure the normal operation of the vehicle; when the maximum output power of the AC charging equipment can meet the charging needs of the power battery, the range extender battery is charged with the maximum charging power that the AC charging equipment can provide to improve the charging efficiency of the range extender battery.

[0038] Secondly, this application also provides a charging and discharging control method for a battery system, applied to the battery system of the first aspect. The method includes: acquiring the operating state of the battery system; acquiring the required driving power of the drive mechanism when the battery system is in a discharging state; and controlling the charging and discharging of the range extender battery according to the required driving power, the charging efficiency of the on-board charger, and the discharging efficiency of the AC / DC conversion component.

[0039] Within a high power range for charge and discharge efficiency, the range-extended battery exhibits high charge and discharge efficiency, resulting in higher energy utilization. In this application, the discharge power range of the range-extended battery is determined by the discharge efficiency of the AC / DC conversion component and the charging efficiency of the on-board charger. Within this discharge power range, both the AC / DC conversion component and the on-board charger operate at higher efficiency levels, enabling the range-extended battery to also achieve high discharge efficiency, thereby improving its energy utilization.

[0040] Fourthly, this application provides a readable storage medium storing computer program instructions that, when executed by a processor, implement the charging and discharging control method of the battery system as described in the second aspect.

[0041] Fifthly, this application provides a computer program product in which instructions, when executed by a processor of an electronic device, cause the electronic device to perform the charging and discharging control method of the battery system as described in the second aspect.

[0042] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0043] The features, advantages, and technical effects of exemplary embodiments of this application will now be described with reference to the accompanying drawings.

[0044] Figure 1 is a schematic diagram of the structure of a battery system according to an embodiment of this application;

[0045] Figure 2 is a schematic diagram of a first connection method between VCU and OPACK according to an embodiment of this application;

[0046] Figure 3 is a schematic diagram of a second connection method between VCU and OPACK according to an embodiment of this application;

[0047] Figure 4 is a flowchart of a charging and discharging control method for a battery system according to another embodiment of this application;

[0048] Figure 5 is a graph showing the first charging efficiency data corresponding to another embodiment of this application;

[0049] Figure 6 is a graph showing the second discharge efficiency data corresponding to another embodiment of this application;

[0050] Figure 7 is a graph showing the initial discharge efficiency range of a range-extended battery according to another embodiment of this application;

[0051] Figure 8 is a flowchart of determining the target output power of a range extender battery according to another embodiment of this application;

[0052] Figure 9 is a flowchart of a charging method for a range-extended battery according to another embodiment of this application;

[0053] Figure 10 is a flowchart of a charging method for a range-extended battery in a DC charging scenario according to another embodiment of this application;

[0054] Figure 11 is a flowchart of a charging method for a range-extended battery in a DC charging scenario according to another embodiment of this application;

[0055] Figure 12 is a flowchart of a charging method for a range-extended battery in an AC charging scenario according to another embodiment of this application.

[0056] The accompanying drawings are not necessarily drawn to scale. The reference numerals in the drawings are explained below:

[0057] VCU - Vehicle Controller; OBC - On-board Charger; H - Range Extender Battery Pack Interface; DC / AC - AC / DC Converter; DC / DC - DC Converter; PACK - Power Battery; OPACK - Range Extender Battery; L1 - Positive High Voltage Line; L3 - Negative High Voltage Line; L2 - Low Voltage Communication Line; EVSE / AC - AC Charging Equipment; EVSE / DC - DC Charging Equipment; HAVC - Heating, Ventilation and Air Conditioning System; M - Drive Mechanism; TN - Low Voltage Power Distribution System; FU - Fuse; TA - Current Sensor; J - Relay; MCU - Motor Controller. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0059] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0060] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0061] In this application, the term "embodiment" is used to mean that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0062] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0063] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0064] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0065] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0066] Electric vehicles currently suffer from two major pain points: short driving range and slow charging, especially pronounced in low-temperature environments. With the widespread adoption of supercharging technology, the slow charging speed of electric vehicles has been significantly improved. Regarding the short driving range issue, related technologies utilize detachable range extenders to increase the driving range of electric vehicles. Specifically, a range extender battery pack interface is installed in the electric vehicle, through which the range extender battery connects to the main battery. A bidirectional DC-DC converter is installed between the range extender battery and the main battery to convert the DC voltage / current to the voltage / current required by either the range extender battery or the main battery. Simultaneously, charging and discharging control of both the main battery and the range extender battery can be achieved.

[0067] However, the aforementioned scheme, which uses a bidirectional DC-DC converter to convert the voltage or current between the range extender battery and the main battery, can only be used in electric vehicles with DC interfaces, and cannot be applied to AC interfaces. Furthermore, in related technologies, when controlling the charging and discharging of the range extender battery, the battery pack only has a DC output interface, which can only increase the driving range of the electric vehicle, resulting in low energy utilization of the range extender battery.

[0068] To address the problems existing in related technologies, this application provides a power supply system that enables AC connection between the range extender battery and the vehicle. Specifically, the range extender battery can be connected to the vehicle via an AC interface, thus making it applicable to electric vehicles with AC interfaces. Furthermore, this application also includes a range extender battery pack interface for connecting the range extender battery to the vehicle. This interface is led out from the AC side inside the vehicle and converts the DC power from the range extender battery into AC power via a bidirectional DC (Direct Current) / AC (Alternating Current) converter.

[0069] In addition, in this application, the range extender battery can be installed in the range extender pack, which also includes the aforementioned bidirectional DC / AC converter and ECU (Electronic Control Unit). The ECU integrates the DC / AC controller and the range extender battery's BMS (Battery Management System), and communicates with the VCU (Vehicle Control Unit). The VCU distributes energy between the vehicle's main battery and the range extender battery according to different operating conditions to efficiently utilize the range extender battery to increase the driving range.

[0070] To further improve the energy utilization rate of the range extender battery, this application also provides a charging and discharging control method, which maximizes the utilization of the range extender battery's energy by controlling the power output of the DC / AC converter and the OBC (On-Board Charger).

[0071] The following describes the battery system provided in the embodiments of this application.

[0072] In one embodiment, Figure 1 shows a schematic diagram of the battery system provided in this application embodiment. As shown in Figure 1, in this application embodiment, the battery system includes at least: a vehicle control unit (VCU), an on-board charger (OBC), and an AC / DC converter. In one example, the battery system may further include a range extender battery pack interface H, configured to realize the AC connection between the range extender battery OPACK and the vehicle.

[0073] The vehicle control unit (VCU) can connect to the DC / AC converter and the OPACK (expansion pack) via the range extender battery pack interface H, and also to the on-board charger (OBC). For example, in Figure 1, L1 is the positive high-voltage line, L3 is the negative high-voltage line (e.g., ground), and L2 is the low-voltage communication line. The VCU connects to the range extender battery pack interface H via the low-voltage communication line L2, and the range extender battery pack interface H connects to the DC / AC converter via the low-voltage communication line L2 to transmit control commands and data. Simultaneously, the range extender battery pack interface H can also connect to the DC / AC converter via the positive high-voltage line L1 and the low-voltage communication line L2 to enable power transfer between the range extender battery pack interface H and the DC / AC converter. The DC / AC converter can also connect to the OPACK (expansion pack) to enable the OPACK to discharge to the vehicle system and to charge the OPACK using external charging equipment.

[0074] In addition, as shown in Figure 1, the vehicle controller (VCU) is also connected to the on-board charger (OBC) via a low-voltage communication line (L2) to control the charging and discharging of the on-board charger (OBC).

[0075] In this embodiment, the vehicle control unit (VCU) can control the charging and discharging of the range extender battery (OPACK) based on the required drive power of the vehicle's drive mechanism, the charging efficiency of the on-board charger (OBC), and the discharging efficiency of the DC / AC converter. The vehicle's drive mechanism may include, but is not limited to, a motor.

[0076] As shown in Figure 1, the charging and discharging of the range extender battery OPACK is inseparable from the on-board charger (OBC) and the DC / AC converter. By combining the charging efficiency of the OBC and the discharging efficiency of the DC / AC converter, the optimal discharge power range (i.e., the target discharge power range) of the range extender battery OPACK can be obtained. Discharging within this discharge power range can improve the energy utilization rate of the range extender battery OPACK.

[0077] As shown in Figure 1, the on-board charger (OBC) is connected to the DC / AC converter via the range extender battery pack interface H. The OBC is connected to the range extender battery pack interface H via positive high-voltage line L1 and negative high-voltage line L3 to realize the power transfer between the OBC and the DC / AC converter.

[0078] In this embodiment, the on-board charger (OBC) can convert the AC power output from the DC / AC converter into DC power to supply power to the drive mechanism. For example, in Figure 1, when the range extender battery (OPACK) needs to supply power to the vehicle's drive mechanism, the vehicle controller (VCU) controls the OPACK to discharge. The DC / AC converter converts the DC power output from the OPACK into AC power, which is then transmitted to the OBC via the range extender battery pack interface H. The OBC then converts the AC power into DC power to provide electrical energy to the vehicle's drive mechanism.

[0079] For the DC / AC converter, it is connected to the OPACK of the range extender battery. It can convert the DC power output from the OPACK of the range extender battery into AC power, and can also convert the AC power output from the AC charging equipment into DC power to charge the OPACK of the range extender battery.

[0080] The range extender battery pack interface H is connected to the range extender battery OPACK via an AC / DC converter. It is configured to transmit the AC power output from the DC / AC converter to the on-board charger (OBC), thereby discharging the range extender battery OPACK. In this embodiment, the range extender battery pack interface H can also transmit the DC power output from the DC / AC converter to the range extender battery OPACK for DC charging. For example, when a DC charging device is charging the vehicle, the on-board charger (OBC) converts the DC power output from the DC charging device into AC power, and then transmits the AC power to the DC / AC converter via the range extender battery pack interface H to convert the AC power into the DC power required by the range extender battery OPACK and charge it.

[0081] As described above, within a high power range for charge and discharge efficiency, the range-extended battery exhibits high charge and discharge efficiency, resulting in higher energy utilization. In this application, the charging and discharging of the range-extended battery requires the participation of an AC / DC converter and an on-board charger. The charging and discharging efficiencies of the AC / DC converter and the on-board charger also affect the charge and discharge efficiency of the range-extended battery. Therefore, in this application, the discharge power range of the range-extended battery is determined by the discharge efficiency of the AC / DC converter and the charging efficiency of the on-board charger. Within this discharge power range, the AC / DC converter and the on-board charger operate at higher efficiency levels, resulting in higher discharge efficiency for the range-extended battery and thus improving its energy utilization.

[0082] The following section provides a further introduction to the various components of the battery system.

[0083] The range extender battery pack interface H may include a first interface and a second interface. The first interface is configured to transmit single-phase AC power, and the second interface is configured to transmit three-phase AC power. The vehicle controller (VCU) issues an interface switching command to the range extender battery OPACK to switch the range extender battery pack interface H to the first or second interface that matches the AC interface type of the on-board charger (OBC). That is, in this embodiment, the AC power obtained by the DC / AC conversion component is either single-phase or three-phase AC power.

[0084] In the above embodiments, the AC interface type of the on-board charger (OBC) is a single-phase AC interface or a three-phase AC interface. The AC interface type of the on-board charger (OBC) can be set before the vehicle leaves the factory. After the vehicle leaves the factory, the vehicle control unit (VCU) can control the switching of the range extender battery pack interface H by detecting the AC interface type of the on-board charger (OBC).

[0085] In this embodiment, the range extender battery pack interface H is consistent with the vehicle's AC charging interface. If the vehicle uses single-phase AC charging, then the range extender battery pack interface H is also single-phase; if the vehicle uses three-phase AC charging, then the range extender battery pack interface H is also three-phase. That is, in this embodiment, the DC / AC converter supports switching between single-phase and three-phase power, capable of outputting both single-phase 220V AC and three-phase 380V AC power. The power rating of the DC / AC converter matches the power rating of the on-board charger (OBC), including 3.3kW, 6.6kW, 11kW, 22kW, and 40kW, etc.

[0086] In addition, in this embodiment of the application, both the on-board charger (OBC) and the AC / DC converter (DC / AC) support bidirectional operation. For the DC / AC converter, AC to DC conversion is charging, and vice versa is discharging. For example, the OBC transmits the output AC power to the DC / AC converter, which then converts the AC power to DC power to charge the OPACK range extender battery. Or, for another example, the OPACK range extender battery discharges DC power, and the DC / AC converter converts the DC power to AC power and transmits it to the OBC, which is discharging for the DC / AC converter.

[0087] It should be noted that in this embodiment, the DC side of the high-voltage architecture of the vehicle remains unchanged. The AC connection between the range extender battery OPACK and the vehicle is achieved by adding the range extender battery pack interface H, thereby making it compatible with vehicles with AC interfaces.

[0088] In addition, it should be noted that the range extender battery pack interface H can provide various types of AC interfaces, thereby expanding the application scope of the range extender battery OPACK. This allows the range extender battery OPACK to not only increase the driving range of vehicles, but also provide power for outdoor and household electricity use.

[0089] The DC / AC conversion component includes a first DC interface, a first AC interface, and a first conversion component. The first DC interface is connected to the range extender battery OPACK. The first AC interface is connected to the second AC interface of the on-board charger (OBC) via the range extender battery pack interface H. The first conversion component is connected between the first DC interface and the first AC interface. It can convert the DC power output from the range extender battery OPACK into AC power, and can also convert the AC power output from the on-board charger (OBC) or the AC power output from the AC charging device EVSE / AC into DC power to charge the range extender battery OPACK.

[0090] The DC / AC converter converts the DC output of the range extender battery OPACK to AC and the AC output of the on-board charger (OBC) to DC, thereby enabling AC connection between the range extender battery OPACK and the vehicle, thus increasing the driving range of electric vehicles with AC interfaces.

[0091] The on-board charger (OBC) includes a second AC interface, a second DC interface, and a second conversion component. The second AC interface connects to an AC charging device via an AC charging interface and to the range extender battery (OPACK) via a range extender battery pack interface H. The AC charging device can be an AC charging device, such as EVSE / AC in Figure 1. The second DC interface connects to a DC charging device via a DC charging interface and to the power battery pack and on-board high-voltage equipment. The second conversion component connects the second AC interface and the first DC interface. It can convert the AC power output from the AC charging device EVSE / AC into DC power to supply the power battery pack and other on-board high-voltage equipment (e.g., HVAC system). Alternatively, it can convert the DC power output from the DC charging device EVSE / DC into AC power and transmit it to the AC / DC conversion component DC / AC via the range extender battery pack interface H to convert the AC power back to DC power to charge the range extender battery (OPACK).

[0092] Taking Figure 1 as an example, after adding a range extender battery, the range extender battery OPACK participates in vehicle driving during driving. The on-board charger (OBC) needs to be in working state during driving. Compared with the original working mode, in this embodiment, the OBC has added two working modes: range extender package driving mode and range extender package charging mode. The vehicle controller (VCU) can control the OBC to enter these two modes without requiring the OBC to judge the transmission signal between the charging device and the OBC; it only needs to output power according to the power request from the VCU.

[0093] In the above example, the transmission signals between the charging device and the on-board charger (OBC) may include a charging connection confirmation signal (CC) and a control guidance signal line (CP). The CC signal is a connection confirmation signal of the on-board charger (OBC). By detecting the voltage of the CC signal, it can be determined whether the charging device is plugged in and its connection status. The CP signal is a confirmation signal that the charging gun of the charging device is connected to the charging port of the vehicle. The maximum allowable current of the charging device can be identified through the CP signal.

[0094] In the range extender drive mode, when the vehicle is in motion, the vehicle controller (VCU) can control the on-board charger (OBC) to enter the range extender drive mode, request the ECU of the range extender battery (OPACK) to enter the discharge mode, and request the on-board charger (OBC) and the range extender battery (OPACK) to output electrical energy according to the power required by the drive mechanism (e.g., the motor).

[0095] For the range extender charging mode, when the vehicle is in charging mode, the vehicle controller (VCU) can control the on-board charger (OBC) to enter the range extender charging mode and request the ECU of the range extender battery (OPACK) to enter the discharge mode. Based on the maximum power of the DC or AC charging equipment and / or the maximum allowable charging power of the power battery (PACK), the on-board charger (OBC) discharges the range extender battery (OPACK).

[0096] In addition, when the vehicle is powered on at low voltage (i.e., not powered on at high voltage) or when the range extender battery OPACK has low power, the vehicle controller VCU can control the on-board charger OBC and the range extender battery OPACK ECU to enter standby mode.

[0097] Corresponding to the working mode of the on-board charger (OBC), the ECU of the range extender battery OPACK has charging, discharging, and standby modes. It outputs power according to the power request of the vehicle controller (VCU). At the same time, the ECU of the range extender battery OPACK can also send relevant parameters of the range extender battery OPACK (such as remaining charge, rated capacity, rated voltage, etc.) to the vehicle controller (VCU). The vehicle controller (VCU) then determines whether the range extender battery OPACK needs to be charged or discharged based on the relevant parameters received.

[0098] By setting up an on-board charger (OBC) to connect the vehicle and the range extender battery (OPACK), the OBC can use the range extender battery (OPACK) to provide power to the main battery (PACK), increasing the vehicle's range. At the same time, it can also realize the transfer of AC power between the range extender battery (OPACK) and the vehicle, improving the flexibility of vehicle charging and discharging.

[0099] In one embodiment, as shown in Figure 1, the battery system further includes a low-voltage power distribution system TN and a DC / DC converter. The DC / DC converter is connected to the second DC interface of the on-board charger (OBC) and the vehicle controller (VCU), and is configured to convert the DC power output from the OBC to power the VCU. The low-voltage power distribution system TN is connected to the DC / DC converter and is configured to power the vehicle's on-board low-voltage equipment.

[0100] In the above embodiments, the vehicle-mounted low-voltage equipment may include vehicle lighting equipment, alarm equipment, and batteries (e.g., 12V lead-acid batteries).

[0101] By setting up DC / DC converters and a TN low-voltage power distribution system, power is supplied to the vehicle's onboard low-voltage equipment after the vehicle is powered on at low voltage.

[0102] In one embodiment, as shown in FIG1, the battery system further includes a motor controller MCU. The first terminal of the motor controller MCU is connected to the drive mechanism M, the second terminal of the motor controller MCU is connected to the on-board charger OBC and the DC charging device EVSE / DC, and the control terminal of the motor controller MCU is connected to the signal output terminal of the vehicle controller VCU.

[0103] Through the above connections, the motor controller MCU can control the drive mechanism M to operate according to the output signal of the vehicle controller VCU. The drive mechanism M can be, but is not limited to, a motor. Taking Figure 1 as an example, the on-board charger (OBC) and the DC / DC converter form the on-board charging assembly. It is connected to the DC transmission line via positive high-voltage line L1 and negative high-voltage line L3. The DC / DC converter converts the DC power output from the OBC and supplies power to the drive mechanism M, the HVAC system (HAVC), and the power battery pack via the DC transmission line. Simultaneously, the DC charging device EVSE / DC can also supply power to the OBC via the DC transmission line.

[0104] In Figure 1, the vehicle control unit (VCU) can send control commands to the motor control unit (MCU), which in turn controls the drive mechanism M according to the control commands. When the drive mechanism M needs to be driven, the MCU can provide power to the drive mechanism M through a DC transmission line to enable the drive mechanism M to operate.

[0105] It should be noted that in the above example, the DC transmission line includes a positive high-voltage line L1 and a negative high-voltage line L3. To protect the circuit, a fuse FU is installed on the positive high-voltage line L1, and a current sensor TA is installed on the negative high-voltage line L3 to prevent excessive current in the positive high-voltage line L1 from damaging vehicle components. Additionally, for ease of management, multiple relays J are installed on both the positive and negative high-voltage lines L1 and L3. The deployment of the relays J is not limited to the method shown in Figure 1 and can be adjusted according to actual needs.

[0106] By configuring the motor controller MCU and communicating with the vehicle controller VCU, the vehicle controller VCU can determine the strategy for providing power to the drive mechanism M based on the drive power required by the drive mechanism M, as well as the power battery PACK, range extender battery OPACK's charge, output power, and power efficiency. This aims to improve energy utilization and reduce energy waste while ensuring the normal operation of the drive mechanism M.

[0107] In one embodiment, the vehicle controller (VCU) can be connected to the range extender battery (OPACK) via the controller area network (CAN) bus. The connection method between the vehicle controller (VCU) and the range extender battery (OPACK) can include the two methods shown in Figures 2 and 3.

[0108] In the first connection method between the vehicle controller (VCU) and the range extender battery (OPACK) as shown in Figure 2, the VCU connects to the on-board charger (OBC) and the OPACK via the vehicle controller local area network (CAN) bus. In this method, the OPACK and OBC use the vehicle CAN bus to connect to the VCU, eliminating the need for an additional bus for the OPACK and reducing costs.

[0109] In the second connection method between the vehicle controller (VCU) and the range extender battery (OPACK) as shown in Figure 3, the VCU connects to the on-board charger (OBC) via the vehicle controller local area network (CAN) bus, and to the range extender battery (OPACK) via the range extender CAN bus. In this method, the range extender battery (OPACK) and the on-board charger (OBC) use different buses to connect to the VCU, reducing the data transmission complexity of using the same bus, thereby reducing the risk of data mistransmission and omission, and improving the stability and reliability of data transmission.

[0110] In one embodiment, the vehicle controller can control the range extender battery OPACK to charge and discharge within a target discharge power range according to the required drive power of the vehicle's drive mechanism. The target discharge power range is a power range determined by the charging efficiency of the on-board charger (OBC) and the discharge efficiency of the DC / AC converter. The target discharge power range is the power corresponding to the optimal discharge efficiency range of the range extender battery OPACK, that is, within the target discharge power range, the discharge efficiency of the range extender battery OPACK is higher than the preset discharge efficiency.

[0111] In one embodiment, the vehicle controller is further configured to acquire first charging efficiency data corresponding to the on-board charger and second discharging efficiency data corresponding to the AC / DC conversion component, and determine the discharge power range corresponding to the range extender battery based on the first charging efficiency data and the second discharging efficiency data.

[0112] In one embodiment, the vehicle controller is further configured to calculate the product of the first charging efficiency data and the second discharging efficiency data to obtain the initial discharge efficiency range corresponding to the range extender battery; determine the discharge efficiency range from the initial discharge efficiency range where the discharge efficiency of the range extender battery is higher than the preset discharge efficiency; and determine the discharge power range corresponding to the discharge efficiency range based on the preset correlation between discharge efficiency and discharge power.

[0113] In one embodiment, the vehicle controller is further configured to determine the target output power of the range extender battery in the following manner: when the required drive power is less than a first discharge power, the target output power of the range extender battery is determined to be 0, wherein the first discharge power is the lower limit of the discharge power range; when the required drive power is greater than or equal to the first discharge power and less than or equal to a second discharge power, the target output power of the range extender battery is determined to be the required drive power, wherein the second discharge power is the upper limit of the discharge power range; when the required drive power is greater than the second discharge power, the target output power of the range extender battery is determined to be the second discharge power.

[0114] In one embodiment, the vehicle controller is further configured to control the range extender battery to provide the required drive power to the drive mechanism in the following manner: when the required drive power is less than a first discharge power, the controller controls the power battery to provide the required drive power to the drive mechanism; when the required drive power is greater than or equal to the first discharge power and less than or equal to a second discharge power, the controller controls the range extender battery to provide the required drive power to the drive mechanism at a target output power; when the required drive power is greater than the second discharge power, the controller controls the range extender battery and the power battery to simultaneously provide the required drive power to the drive mechanism, wherein the sum of the target output power provided by the range extender battery and the output power provided by the power battery is the required drive power.

[0115] In one embodiment, the vehicle controller is further configured to, when the battery system is in a charging state, acquire the maximum output power of the charging device and the charging device type of the charging device; and determine the target charging power of the charging device for charging the range-extending battery based on the maximum output power of the charging device and the charging strategy corresponding to the charging device type.

[0116] In one embodiment, when the charging device is a DC charging device, the vehicle controller determines the target charging power for the range extender battery by the charging device as follows: if the maximum output power of the charging device is less than or equal to the maximum charging power corresponding to the power battery, the target charging power is determined to be 0, and the DC charging device is controlled to charge the power battery; if the maximum output power of the charging device is greater than the maximum charging power corresponding to the power battery, the difference between the maximum output power of the charging device and the maximum charging power corresponding to the power battery is calculated to obtain the charging power difference; based on the charging power difference and the charging power range corresponding to the range extender battery, the target charging power for the range extender battery is determined.

[0117] In one embodiment, the vehicle controller is further configured to determine the target charging power for charging the range extender battery by the charging device in the following manner: if the charging power difference is less than a first charging power, the target charging power is determined to be 0, wherein the first charging power is the lower limit of the charging power range; if the charging power difference is greater than or equal to the first charging power and less than or equal to a second charging power, the target charging power is determined to be the charging power difference, wherein the second charging power is the upper limit of the charging power range; if the charging power difference is greater than the second charging power, the target charging power is determined to be the second charging power.

[0118] In one embodiment, the vehicle controller is further configured to acquire first discharge efficiency data corresponding to the on-board charger and second charging efficiency data corresponding to the AC / DC conversion component; calculate the product of the first discharge efficiency data and the second charging efficiency data to obtain an initial charging efficiency range corresponding to the range extender battery; determine the charging efficiency range from the initial charging efficiency range where the charging efficiency of the range extender battery is higher than a preset charging efficiency; and determine the charging power range corresponding to the charging efficiency range based on a preset correlation between charging efficiency and charging power.

[0119] In one embodiment, when the charging device is an AC charging device, the vehicle controller determines the target charging power for the range extender battery by: acquiring a third charging power and a fourth charging power, wherein the third charging power is the maximum charging power corresponding to the on-board charger, and the fourth charging power is the maximum charging power corresponding to the AC / DC conversion component; if the maximum output power of the charging device is less than the third charging power, the target charging power is determined to be 0, and the on-board charger is controlled to charge the power battery at the maximum output power of the charging device; if the maximum output power of the charging device is greater than or equal to the third charging power, and less than or equal to the fifth charging power, the target charging power is determined to be a sixth charging power, wherein the fifth charging power is the sum of the third and fourth charging power, and the sixth charging power is the difference between the maximum output power of the charging device and the third charging power; if the maximum output power of the charging device is greater than the fifth charging power, the target charging power is determined to be the fourth charging power.

[0120] The process of implementing the above control strategy by the vehicle controller will be further described in the following text, and will not be repeated here.

[0121] This concludes the introduction to the battery system provided in the embodiments of this application.

[0122] As described above, the battery system provided in this application increases the electric vehicle's power by adding a removable range extender battery, thereby improving its driving range. Furthermore, currently available electric vehicles generally suffer from short driving range and slow charging in northern winters, significantly impacting the user experience. The removable range extender battery provides users with the option to selectively add a range extender battery to increase driving range in winter or when long-distance travel is required, and can be removed when not needed, thus improving the flexibility of adjusting the vehicle's driving range.

[0123] In addition, in the battery system provided in this application embodiment, the power of the range extender battery can be configured according to customer needs. The ECU corresponding to the range extender battery communicates with the vehicle controller (VCU). The VCU controls the charging and discharging of the range extender battery and the output power to improve the energy utilization rate of the range extender battery.

[0124]

[0125] The following describes the charging and discharging control method of the battery system provided in the embodiments of this application, in conjunction with the battery system.

[0126] In one embodiment, Figure 4 shows a flowchart of a charging and discharging control method for a battery system. This method can be applied to a battery system, specifically to the vehicle control unit (VCU) of the battery system. As shown in Figure 4, the method may include the following steps S401 to S404:

[0127] Step S401: Obtain the operating status of the battery system.

[0128] In step S401, the operating state of the battery system may include a charging state and a discharging state. In the discharging state, the on-board charger (OBC) operates in the range extender drive mode; in the charging state, the on-board charger (OBC) operates in the range extender charging mode.

[0129] In one example, the vehicle control unit (VCU) can determine the operating state of the battery system by detecting the vehicle's driving status and the battery parameters of the power battery. For instance, when the VCU detects that the vehicle is in motion and the power battery pack has insufficient charge, it controls the on-board charger (OBC) to enter the range extender drive mode, at which time the battery system is in a discharging state. As another example, when the VCU detects that the vehicle is stationary and the vehicle's AC charging interface or DC charging interface is connected to the charging equipment, it controls the OBC to enter the range extender drive mode, at which time the battery system is in a charging state.

[0130] Step S402: When the battery system is in a discharged state, obtain the required drive power of the drive mechanism.

[0131] In step S402, after determining that the battery system is in a discharging state, the vehicle controller (VCU) can obtain the driving parameters such as current and voltage required for the operation of the drive mechanism M through the motor controller (MCU), and calculate the driving parameters to determine the required driving power of the drive mechanism M. The required driving power can be calculated using relevant algorithms already available in the art, which will not be listed here.

[0132] Step S403: Control the charging and discharging of the range extender battery according to the required driving power, the charging efficiency of the on-board charger, and the discharging efficiency of the DC-DC converter.

[0133] In step S403, the vehicle controller determines the target output power of the range extender battery based on the required drive power and the corresponding discharge power range of the range extender battery, and controls the range extender battery to provide the required drive power to the drive mechanism at the target output power. The discharge power range corresponding to the range extender battery is determined by the charging efficiency of the on-board charger and the discharge efficiency of the AC / DC conversion component. This range represents the range where the range extender battery's discharge efficiency is higher than a preset discharge efficiency; that is, this discharge power range represents a high discharge efficiency range for the range extender battery. Controlling the range extender battery discharge within this discharge power range can effectively improve its discharge efficiency.

[0134] By determining the target discharge power of the range extender battery within the power range with higher discharge efficiency through step S403, and then controlling the output of the range extender battery to the target discharge power, the energy utilization rate of the range extender battery can be effectively improved.

[0135] Based on the scheme defined in steps S401 to S403 above, it can be seen that within a power range with higher charge and discharge efficiency, the range extender battery has higher charge and discharge efficiency, and its corresponding energy utilization rate is also higher. In this embodiment, the discharge power range of the range extender battery is determined by the discharge efficiency of the AC / DC conversion component and the charging efficiency of the on-board charger. Within this discharge power range, the AC / DC conversion component and the on-board charger operate in a higher efficiency range, enabling the range extender battery to also have higher discharge efficiency, thereby improving the energy utilization rate of the range extender battery.

[0136] The specific implementation method of the method provided in the embodiments of this application is described below.

[0137] As shown in the schematic diagram of the battery system in Figure 1, the charging and discharging of the range extender battery requires the participation of AC / DC conversion components and on-board charger. In order to improve the discharge efficiency of the range extender battery, it is first necessary to determine the optimal discharge power range of the range extender battery.

[0138] In one embodiment, firstly, the first charging efficiency data corresponding to the on-board charger and the second discharging efficiency data corresponding to the AC / DC conversion component are obtained. Then, based on the first charging efficiency data and the second discharging efficiency data, the discharge power range corresponding to the range extender battery can be determined.

[0139] In the above embodiments, the first charging efficiency data is used to characterize the relationship between the charging power and charging efficiency of the on-board charger. It can be represented by a function expression or by a curve. For example, Figure 5 shows a curve corresponding to the first charging efficiency data. In this curve, the horizontal axis represents the charging power of the on-board charger, and the vertical axis represents the charging efficiency of the on-board charger.

[0140] In the above embodiments, the second discharge efficiency data is used to characterize the relationship between the discharge power and discharge efficiency of the AC / DC conversion component. It can be represented by a function expression or by a curve. For example, Figure 6 shows a curve corresponding to the second discharge efficiency data. In this curve, the horizontal axis represents the discharge power of the AC / DC conversion component, and the vertical axis represents the discharge efficiency of the AC / DC conversion component.

[0141] After obtaining the first charging efficiency data and the second discharging efficiency data, the corresponding discharge power range of the range extender battery can be obtained through data fitting. The discharge power range of the range extender battery is determined by the discharge efficiency of the AC / DC conversion component and the charging efficiency of the on-board charger, so that the range extender battery discharges within a higher efficiency discharge power range, thereby improving the discharge efficiency of the range extender battery.

[0142] In one embodiment, the discharge power range corresponding to the range-extended battery can be determined by curve fitting of the first charging efficiency data and the second discharging efficiency data.

[0143] Specifically, the product of the first charging efficiency data and the second discharging efficiency data is calculated to obtain the initial discharge efficiency range corresponding to the range extender battery; then, the discharge efficiency range in which the discharge efficiency of the range extender battery is higher than the preset discharge efficiency is determined from the initial discharge efficiency range; and finally, the discharge power range corresponding to the discharge efficiency range is determined according to the preset correlation between discharge efficiency and discharge power.

[0144] Taking Figures 5 and 6 as examples, for the on-board charger and AC / DC converter, under the same charging and discharging power, the product of the charging efficiency of the on-board charger and the discharging efficiency of the AC / DC converter can be calculated to obtain the discharge efficiency of the range extender battery at that discharge power. For example, when the charging power is 1kW, the charging efficiency of the on-board charger is 88.34%; when the discharging power is 1kW, the discharging efficiency of the AC / DC converter is 86.34%, then when the discharging power is 1kW, the discharge efficiency of the range extender battery is 76.27%. Similarly, the relationship between the discharge power and discharge efficiency of the range extender battery can be obtained, as shown in Figure 7, which represents the initial discharge efficiency range of the range extender battery. Then, a preset discharge efficiency (e.g., 88%) is set according to actual needs, and the discharge power of the range extender battery when the discharge efficiency is greater than 88% is determined from Figure 7, thus obtaining the discharge power range.

[0145] The discharge power range of the range extender battery is determined by using the first charging efficiency data corresponding to the on-board charger and the second discharge efficiency data corresponding to the AC / DC conversion component. Within this discharge power range, the AC / DC conversion component and the on-board charger operate in a higher efficiency range, which enables the range extender battery to also have a higher discharge efficiency, thereby improving the energy utilization rate of the range extender battery.

[0146] Furthermore, after determining the discharge power range corresponding to the range extender battery, the vehicle controller can determine the target output power of the range extender battery based on the required drive power and the corresponding discharge power range. As shown in Figure 8, this process may include the following steps:

[0147] Step S801, in demand drive power P M Less than the first discharge power P 1min In this case, if the target output power of the range extender battery is determined to be 0, the range extender battery will not work, and the vehicle controller will control the power battery to provide the required drive power to the drive mechanism.

[0148] In step S801, the first discharge power P 1min P represents the lower limit of the discharge power within the discharge power range. 1min ≤P M ≤P 1max .

[0149] Step S802, in demand drive power P M Greater than or equal to the first discharge power P 1min And less than or equal to the second discharge power P 1max In this case, the target output power of the range extender battery is determined as the required drive power. At this time, the vehicle controller controls the range extender battery to provide the required drive power to the drive mechanism at the target output power.

[0150] In step S802, the second discharge power P 1max This represents the upper limit of the discharge power range.

[0151] Step S803, in demand drive power P M Greater than the second discharge power P 1max In this scenario, the target output power of the range extender battery is determined to be the second discharge power. At this time, the vehicle controller controls both the range extender battery and the main battery to simultaneously provide the required drive power to the drive mechanism. The sum of the target output power provided by the range extender battery and the output power provided by the main battery is the required drive power. That is, in this scenario, the range extender battery outputs its maximum discharge power, and the main battery replenishes the remaining drive power P required by the drive mechanism. M -P 1max .

[0152] The discharge strategy for the range extender battery provided in steps S801 to S803 enables the range extender battery to discharge within a discharge power range with higher discharge efficiency, thereby improving the discharge efficiency of the range extender battery and thus improving the energy utilization rate of the range extender battery.

[0153] In one embodiment, when the battery system is in a charging state, the vehicle controller further determines the target charging power for the range extender battery based on the output power of the charging equipment. As shown in Figure 9, the charging method for the range extender battery may include the following steps:

[0154] Step S401: Obtain the operating status of the battery system.

[0155] Step S902: When the battery system is in a charging state, obtain the maximum output power of the charging device and the charging device type of the charging device.

[0156] In step S902, the charging device type of the charging device can include DC charging device and AC charging device. The vehicle controller can determine the charging device type by judging the connection status between the DC charging interface and the AC charging interface. For example, when a charging device is detected connected to the DC charging interface, it can be determined that the charging device is a DC charging device; when a charging device is detected connected to the AC charging interface, it can be determined that the charging device is an AC charging device.

[0157] Step S903: Determine the target charging power for the range-extending battery by the charging device based on the maximum output power of the charging device and the charging strategy corresponding to the type of charging device.

[0158] In step S903, when charging the range extender battery, different charging strategies are adopted according to the type of charging equipment to improve the charging efficiency of the range extender battery. Furthermore, the maximum output power of the charging equipment is considered during the charging process, so that, under certain conditions, the maximum output power of the charging equipment can be used to charge the range extender battery, further improving its charging efficiency.

[0159] The following section introduces the charging strategies for range-extending batteries in two scenarios.

[0160] When the charging equipment is a DC charging equipment, the charging process of the range extender battery can be as shown in Figure 10, and the process may include the following steps:

[0161] Step S1001, at the maximum output power P of the charging device 直流 Less than or equal to the maximum charging power P corresponding to the power battery PACK In this case, the target charging power is determined to be 0, and the DC charging equipment is controlled to charge the power battery.

[0162] In this scenario, the DC charging equipment prioritizes charging the power battery, and only charges the range extender battery after the power battery has finished charging.

[0163] Step S1002, at the maximum output power P of the charging device 直流 Greater than the maximum charging power P corresponding to the power battery PACK Under these conditions, calculate the maximum output power P of the charging device. 直流 The maximum charging power P corresponding to the power battery PACK The difference is used to obtain the charging power difference P. 直流 -P PACK ;

[0164] Step S1003, based on the charging power difference P 直流 -P PACK And the charging power range corresponding to the range-extending battery, determine the target charging power of the charging equipment for charging the range-extending battery.

[0165] The range extender battery can be charged through steps S1001 to S1003 described above. When the maximum output power of the charging equipment cannot meet the charging needs of the power battery, the power battery is charged first to ensure the normal operation of the vehicle. After the power battery is fully charged, the range extender battery is charged to increase the vehicle's driving range. When the maximum output power of the charging equipment can meet the charging needs of the power battery, the range extender battery is charged according to its charging power range to improve its charging efficiency.

[0166] Step S1003 can be divided into three cases, as shown in Figure 11:

[0167] Step S1101, at the charging power difference P 直流 -P PACK Less than the first charging power P 2min In this scenario, the target charging power is set to 0. The DC charging device will not charge the range extender battery in this condition.

[0168] In step S1101, the first charging power P 2min This represents the lower limit of the charging power range.

[0169] Step S1102, at the charging power difference P 直流 -P PACK Greater than or equal to the first charging power P 2min And less than or equal to the second charging power P 2max In this case, the target charging power is determined as the difference in charging power.

[0170] In step S1102, the second charging power P 2max This represents the upper limit of the charging power range. In this scenario, the remaining power (i.e., the charging power difference) after the DC charging device has charged the power battery is within the charging power range of the range extender battery. At this time, using the remaining power to charge the range extender battery can improve the charging efficiency of the range extender battery.

[0171] Step S1103, at the charging power difference P 直流 -P PACK Greater than the second charging power P 2max In this scenario, the target charging power is determined as the second charging power. That is, in this case, the remaining power (i.e., the charging power difference) after the DC charging equipment has charged the power battery exceeds the charging power range of the range extender battery. At this point, the maximum charging power that the range extender battery can withstand (i.e., the second charging power P) is determined. 2max This method charges the range extender battery, ensuring safe charging while also improving charging efficiency.

[0172] Through the above steps S1101 to S1103, when the maximum output power of the charging equipment can meet the charging needs of the power battery, the range-extending battery is charged in combination with the charging power range of the range-extending battery. This ensures the safe charging of the range-extending battery while also improving its charging efficiency.

[0173] It should be noted that in steps S1101 to S1103 above, the charging power range of the range extender battery is determined by the discharge efficiency data corresponding to the on-board charger and the charging efficiency data corresponding to the AC / DC conversion component.

[0174] In one embodiment, first discharge efficiency data corresponding to the on-board charger and second charging efficiency data corresponding to the AC / DC conversion component are obtained; then, the product of the first discharge efficiency data and the second charging efficiency data is calculated to obtain the initial charging efficiency range corresponding to the range extender battery; then, the charging efficiency range in which the charging efficiency of the range extender battery is higher than the preset charging efficiency is determined from the initial charging efficiency range; then, the charging power range corresponding to the charging efficiency range is determined according to the preset correlation between charging efficiency and charging power.

[0175] It should be noted that the method for determining the charging power range of a range-extending battery is the same as that for determining the discharging power range of a range-extending battery, and will not be repeated here.

[0176] The charging power range of the range extender battery is determined by using the first discharge efficiency data corresponding to the on-board charger and the second charging efficiency data corresponding to the AC / DC conversion component. Within this charging power range, the AC / DC conversion component and the on-board charger operate in a higher efficiency range, which enables the range extender battery to also have a higher charging efficiency, thereby improving the charging efficiency of the range extender battery.

[0177] When the charging equipment is an AC charging equipment, the charging process of the range extender battery can be as shown in Figure 12, and the process can include the following steps S1201 to S1203:

[0178] Step S1201, at the maximum output power P of the charging device 交流 Less than the third charging power P OBC In this case, the target charging power is determined to be 0, and the on-board charger is controlled to operate at the maximum output power P of the charging equipment. 交流 Charge the power battery.

[0179] In step S1201, the third charging power P OBC This refers to the maximum charging power corresponding to the on-board charger, which can be determined by the vehicle controller based on the CC / CP signal.

[0180] In the scenario defined in step S1201, the range extender battery is not charged, and the on-board charger charges the vehicle's power battery at the maximum output power of the AC charging equipment. Using the maximum output power to charge the power battery can improve the charging efficiency of the power battery.

[0181] Step S1202, at the maximum output power P of the charging device 交流 Greater than or equal to the third charging power P OBC And less than or equal to the fifth charging power P OBC +P DCACIn this case, the target charging power is determined to be the sixth charging power P. 交流 -P OBC .

[0182] In step S1202, the fifth charging power is the third charging power P. OBC With the fourth charging power P DCAC The sum of the fourth charging power P DCAC The sixth charging power is the maximum charging power corresponding to the AC / DC conversion component; the sixth charging power is the maximum output power P of the charging equipment. 交流 With the third charging power P OBC difference.

[0183] In this scenario, the AC charging equipment prioritizes charging the vehicle's main battery, with any excess power used to charge the range extender battery. The power used to charge the main battery is the third charging power P. OBC The charging power for the range extender battery is the sixth charging power P. 交流 -P OBC .

[0184] Step S1203, at the maximum output power P of the charging device 交流 Greater than the fifth charging power P OBC +P DCAC In this case, the target charging power is determined to be the fourth charging power P. DCAC .

[0185] In this scenario, the maximum power is used to charge both the vehicle's main battery and range extender battery, where the charging power for the vehicle's main battery is P. OBC The power used to charge the range extender battery is P. DCAC .

[0186] Through the above steps S1201 to S1203, when the maximum output power of the AC charging equipment cannot meet the charging needs of the power battery, the power battery is charged first to ensure the normal operation of the vehicle; when the maximum output power of the AC charging equipment can meet the charging needs of the power battery, the range extender battery is charged with the maximum charging power that the AC charging equipment can provide to improve the charging efficiency of the range extender battery.

[0187] This concludes the explanation of the methods provided in the embodiments of this application.

[0188] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0189] In one embodiment, this application also provides a readable storage medium storing computer program instructions, which, when executed by a processor, implement the above-described charging and discharging control method for a battery system.

[0190] In one embodiment, this application also provides a computer program product in which the instructions, when executed by the processor of an electronic device, cause the electronic device to perform the above-described battery system charging and discharging control method.

[0191] It should be clarified that this application is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of this application is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of this application.

[0192] The functional blocks shown in the above block diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this application are programs or code segments used to perform the required tasks. Programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried on a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0193] It should also be noted that the exemplary embodiments mentioned in this application describe methods or systems based on a series of steps or apparatus. However, this application is not limited to the order of the above steps; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0194] The foregoing flowcharts and / or block diagrams of a battery system and a charging / discharging control method for a battery system according to embodiments of this application have described various aspects of the present application. It should be understood that each block in the flowcharts and / or block diagrams, and combinations of blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to create a machine such that these instructions, executable via the processor of the computer or other programmable data processing apparatus, enable the implementation of the functions / actions specified in one or more blocks of the flowcharts and / or block diagrams. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field-programmable logic circuit. It is also understood that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can also be implemented by dedicated hardware performing the specified functions or actions, or can be implemented by a combination of dedicated hardware and computer instructions.

[0195] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery system, comprising: Vehicle controller, on-board charger, and AC / DC conversion components; The vehicle controller is connected to the AC / DC conversion component and the range extender battery, and is also connected to the on-board charger. It is configured to control the charging and discharging of the range extender battery according to the required driving power of the vehicle's drive mechanism, the charging efficiency of the on-board charger, and the discharging efficiency of the AC / DC conversion component. The on-board charger is connected to the AC / DC conversion component and is configured to convert the AC power output by the AC / DC conversion component into DC power and supply power to the drive mechanism. The AC / DC conversion component is connected to the range extender battery and is configured to convert the DC power output by the range extender battery into AC power.

2. The system according to claim 1, wherein, The AC / DC conversion component converts AC power into single-phase AC power or three-phase AC power.

3. The system according to claim 1, wherein, The AC / DC conversion assembly includes a first DC interface, a first AC interface, and a first conversion component; The first DC interface is connected to the range extender battery; The first AC interface is connected to the second AC interface of the on-board charger; The first conversion component is connected between the first DC interface and the first AC interface.

4. The system according to claim 3, wherein, The on-board charger includes a second AC interface, a second DC interface, and a second conversion component; The second AC interface is connected to the AC charging device via the AC charging interface and is also connected to the range extender battery; The second DC interface is connected to the DC charging equipment via the DC charging interface, and is also connected to the power battery and the vehicle-mounted high-voltage equipment. The second conversion component is connected between the second AC interface and the first DC interface.

5. The system according to claim 4, wherein, The battery system also includes: A DC-DC converter, connected to the second DC interface and the vehicle controller, is configured to convert the DC power output from the on-board charger to power the vehicle controller. The low-voltage power distribution system, connected to the DC-DC conversion component, is configured to supply power to the vehicle's on-board low-voltage equipment.

6. The system according to claim 4, wherein, The battery system also includes: a motor controller; The first end of the motor controller is connected to the drive mechanism, the second end of the motor controller is connected to the on-board charger and the DC charging equipment, and the control end of the motor controller is connected to the signal output end of the vehicle controller. The motor controller is configured to control the operation of the drive mechanism according to the output signal of the vehicle controller.

7. The system according to any one of claims 1 to 6, wherein, The vehicle controller is connected to the on-board charger and the range extender battery via the vehicle controller local area network bus CAN.

8. The system according to any one of claims 1 to 6, wherein, The vehicle controller is connected to the on-board charger via the vehicle controller local area network bus CAN, and is also connected to the range extender battery via the range extender CAN.

9. The system according to claim 1, wherein, The vehicle controller is configured to control the range extender battery to charge and discharge within a target discharge power range according to the drive power requirements of the vehicle's drive mechanism, wherein the target discharge power range is a power range determined by the charging efficiency of the on-board charger and the discharge efficiency of the AC / DC conversion component.

10. The system according to claim 9, wherein, The vehicle controller is also configured to acquire first charging efficiency data corresponding to the on-board charger and second discharge efficiency data corresponding to the AC / DC conversion component, and determine the discharge power range corresponding to the range extender battery based on the first charging efficiency data and the second discharge efficiency data.

11. The system according to claim 10, wherein, The vehicle controller is further configured to calculate the product of the first charging efficiency data and the second discharging efficiency data to obtain the initial discharge efficiency range corresponding to the range extender battery; determine the discharge efficiency range from the initial discharge efficiency range where the discharge efficiency of the range extender battery is higher than the preset discharge efficiency; and determine the discharge power range corresponding to the discharge efficiency range based on the preset correlation between discharge efficiency and discharge power.

12. The system according to claim 10 or 11, wherein, The vehicle controller is also configured to determine the target output power of the range extender battery in the following manner: When the required driving power is less than the first discharge power, the target output power of the range extender battery is determined to be 0, wherein the first discharge power is the lower limit of the discharge power range. When the required driving power is greater than or equal to the first discharge power and less than or equal to the second discharge power, the target output power of the range extender battery is determined to be the required driving power, wherein the second discharge power is the upper limit of the discharge power range. If the required driving power is greater than the second discharge power, the target output power of the range extender battery is determined to be the second discharge power.

13. The system according to claim 12, wherein, The vehicle controller is also configured to control the range extender battery to provide the required drive power to the drive mechanism in the following manner: When the required driving power is less than the first discharge power, the power battery is controlled to provide the required driving power to the drive mechanism. When the required driving power is greater than or equal to the first discharge power and less than or equal to the second discharge power, the range extender battery is controlled to provide the required driving power to the drive mechanism at the target output power; When the required driving power is greater than the second discharge power, the range extender battery and the power battery are controlled to simultaneously provide the required driving power to the drive mechanism, wherein the sum of the target output power provided by the range extender battery and the output power provided by the power battery is the required driving power.

14. The system according to claim 9, wherein, The vehicle controller is also configured to, when the battery system is in a charging state, acquire the maximum output power of the charging device and the charging device type of the charging device; and determine the target charging power of the charging device for charging the range extender battery based on the maximum output power of the charging device and the charging strategy corresponding to the charging device type.

15. The system according to claim 14, wherein, When the charging device is a DC charging device, the vehicle controller determines the target charging power of the charging device for the range extender battery in the following manner: If the maximum output power of the charging device is less than or equal to the maximum charging power corresponding to the power battery, the target charging power is determined to be 0, and the DC charging device is controlled to charge the power battery. When the maximum output power of the charging device is greater than the maximum charging power corresponding to the power battery, the difference between the maximum output power of the charging device and the maximum charging power corresponding to the power battery is calculated to obtain the charging power difference. Based on the charging power difference and the charging power range corresponding to the range extender battery, the target charging power for the charging device to charge the range extender battery is determined.

16. The system according to claim 15, wherein, The vehicle controller is also configured to determine the target charging power for the range extender battery by the charging device in the following manner: If the difference in charging power is less than the first charging power, the target charging power is determined to be 0, wherein the first charging power is the lower limit of the charging power range. If the charging power difference is greater than or equal to the first charging power and less than or equal to the second charging power, the target charging power is determined to be the charging power difference, wherein the second charging power is the upper limit of the charging power range. If the difference in charging power is greater than the second charging power, the target charging power is determined to be the second charging power.

17. The system according to claim 15 or 16, wherein, The vehicle controller is also configured to acquire first discharge efficiency data corresponding to the on-board charger and second charging efficiency data corresponding to the AC / DC conversion component; Calculate the product of the first discharge efficiency data and the second charging efficiency data to obtain the initial charging efficiency range corresponding to the range extender battery; From the initial charging efficiency range, determine the range-extending battery's charging efficiency range that is higher than the preset charging efficiency. Based on the preset correlation between charging efficiency and charging power, the charging power range corresponding to the charging efficiency range is determined.

18. The system according to claim 14, wherein, When the charging device is an AC charging device, the vehicle controller determines the target charging power of the charging device for the range extender battery in the following manner: Obtain a third charging power and a fourth charging power, wherein the third charging power is the maximum charging power corresponding to the on-board charger, and the fourth charging power is the maximum charging power corresponding to the AC / DC conversion component; If the maximum output power of the charging device is less than the third charging power, the target charging power is determined to be 0, and the on-board charger is controlled to charge the power battery at the maximum output power of the charging device. When the maximum output power of the charging device is greater than or equal to the third charging power and less than or equal to the fifth charging power, the target charging power is determined to be the sixth charging power, wherein the fifth charging power is the sum of the third charging power and the fourth charging power, and the sixth charging power is the difference between the maximum output power of the charging device and the third charging power; If the maximum output power of the charging device is greater than the fifth charging power, the target charging power is determined to be the fourth charging power.

19. The system according to claim 1, wherein, The battery system also includes a range extender battery pack interface, configured to connect the range extender battery to the vehicle via AC connection; The range extender battery pack interface includes a first interface and a second interface, wherein the first interface is configured to transmit single-phase AC power and the second interface is configured to transmit three-phase AC power.

20. A method for controlling the charging and discharging of a battery system, applied to the battery system according to any one of claims 1 to 19, the method comprising: Obtain the operating status of the battery system; When the battery system is in a discharging state, the required drive power of the drive mechanism is obtained; The charging and discharging of the range extender battery is controlled according to the required driving power, the charging efficiency of the on-board charger, and the discharging efficiency of the AC / DC conversion component.

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