Multi-cluster power battery system charging method and battery management system

Abstract

The embodiment of the invention provides a vehicle multi-cluster power battery system charging method and a battery management system, and the method comprises the steps: determining to enter a charging mode, and if a first difference value between a highest first voltage and a lowest first voltage in current first voltages is greater than a target threshold value; if yes, the first battery cluster corresponding to the lowest first voltage serves as a first second battery cluster to be connected to the high-voltage direct-current circuit; wherein the first voltage is the total voltage of the corresponding first battery cluster, and the first battery cluster in the charging mode is the battery cluster currently in a to-be-charged state; then, the charger is notified to output charging current to the high-voltage direct-current circuit for charging; when it is determined that a second battery cluster which is being charged exists, the first battery cluster corresponding to the lowest first voltage serves as a new second battery cluster to be connected to the high-voltage direct-current circuit to be charged whenever it is determined that a cluster combining condition is met according to the current second voltage and the current lowest first voltage; wherein the second voltage is the total voltage of the whole circuit structure formed by the second battery clusters.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery management, and in particular to a charging method for a vehicle multi-cluster power battery system and a battery management system. BACKGROUND

[0002] At present, there is a power battery solution that uses a multi-cluster battery system structure to improve the endurance of an electric vehicle. However, since the multi-cluster battery system includes multiple battery clusters, the states of different battery clusters in the use process can be different. Therefore, when charging the multi-cluster battery system, if multiple battery clusters are charged at the same time due to the different states of different clusters, it can cause overcharging or undercharging of some battery clusters. SUMMARY

[0003] The embodiments of the present application provide a charging method for a vehicle multi-cluster power battery system and a battery management system to solve the problem that, in the prior art, when charging a multi-cluster battery system, if multiple battery clusters are charged at the same time due to the different states of different clusters, it can cause overcharging or undercharging of some battery clusters.

[0004] In a first aspect, the embodiments of the present application provide a charging method for a vehicle multi-cluster power battery system, which is applied to a general controller of a battery management system (BMS) of a vehicle. The general controller is electrically connected with a charger, a general charging switch component of a high-voltage direct-current circuit, and multiple master controllers of the BMS. Each master controller is connected with a battery cluster one by one, and each battery cluster includes multiple electrically connected single batteries. The general charging switch component is a switch in the high-voltage direct-current circuit for controlling the on-off of the electrical circuit of the high-voltage direct-current circuit and the charger. The method includes the following steps. After detecting a charging connection confirmation signal generated by the charger, it is determined that the charging mode is entered. After entering the charging mode, if the first difference between the highest first voltage and the lowest first voltage among the current first voltages is greater than a target threshold, a clustering instruction is sent to the master controller corresponding to the lowest first voltage, so that the master controller responds to the clustering instruction and connects the first battery cluster corresponding to the lowest first voltage as the first second battery cluster to the high-voltage direct-current circuit. For any first voltage, the first voltage is the total voltage of the corresponding first battery cluster. When in the charging mode, the first battery cluster is a battery cluster currently in the charging state. The first voltage is collected by the master controller connected with the first battery cluster. If it is determined that the first second battery cluster has been connected to the high-voltage DC circuit, then the main charging switch component corresponding to the high-voltage DC circuit is closed, and a charging ready message is sent to the charger; so as to receive the charging current output by the charger in response to the charging ready message through the high-voltage DC circuit and charge the first second battery cluster. When it is determined that a second battery cluster is being charged, whenever the clustering condition is met based on the current second voltage and the lowest first voltage among the current first voltages, a clustering command is sent to the main controller corresponding to the current lowest first voltage, so that the main controller responds to the clustering command and connects the first battery cluster corresponding to the lowest first voltage as a new second battery cluster to the high-voltage DC circuit for charging; wherein, the second voltage is the total voltage of the overall circuit structure composed of the second battery clusters collected by the main controller.

[0005] Optionally, the method further includes: After determining that the charging mode has been entered, if the first difference between the highest and lowest first voltages among the current first voltages is less than or equal to the target threshold, then according to the order of the first voltages from low to high, the corresponding clustering command is sent to the corresponding main controller in sequence, so that the main controller responds to the clustering command and connects the corresponding first battery cluster as the second battery cluster to the high voltage DC circuit. If it is determined that all the second battery clusters have been connected to the high-voltage DC circuit, the main charging switch component corresponding to the high-voltage DC circuit is closed, and a charging ready message is sent to the charger; so as to receive the charging current output by the charger in response to the charging ready message through the high-voltage DC circuit and charge the second battery clusters.

[0006] Optionally, the method further includes: Whenever the number of the second battery clusters changes, a target current is determined based on the minimum allowable charging current of each second battery cluster, the current number of the second battery clusters, the rated capacity of the multi-cluster power battery system, the current decay coefficient, and the rated upper limit of the charging current corresponding to the charger. A charging parameter request message is sent to the charger to indicate the target current, so that the charger responds to the charging parameter request message to supply power to the high voltage DC circuit with the target voltage and the target current. The target voltage is the rated voltage of the battery cluster.

[0007] Optionally, the method further includes: When it is determined that there is a third battery cluster in each of the current second battery clusters that has reached the full charge condition, a current adjustment command is sent to the charger to request the charger to adjust the current value of the charging current output to the high voltage DC circuit to the rated minimum current value of the charger. When the power-off condition is determined to be met, a de-cluster command is sent to the main controller corresponding to the third battery cluster, so that the main controller disconnects the third battery cluster from the high-voltage DC circuit in response to the de-cluster command. The power-off conditions include: the current value of the charging current received by the high-voltage DC circuit is less than a preset current threshold, or the duration between the current moment and the moment the current adjustment command is sent is greater than a preset power-off duration.

[0008] Optionally, before closing the main charging switch component corresponding to the high-voltage DC circuit, the method further includes: It was determined that the non-power system load components were connected to the high-voltage DC circuit.

[0009] Optionally, the method further includes: When the charging end condition is determined to be met, a current adjustment command is sent to the charger to request the charger to adjust the current value of the charging current output to the high voltage DC circuit to the rated minimum current value of the charger. When the power-off conditions are met, disconnect the main charging switch component; After confirming that the main charging switch component is open, the charging mode is exited, and the components that have been connected to the high-voltage DC circuit are disconnected from the high-voltage DC circuit; wherein, the components include the non-power system load components; The charging termination conditions include: whenever the number of the second battery clusters changes, determining that there are no second battery clusters currently being charged by the high-voltage DC circuit; or, receiving a charging termination command. The power-off conditions include: the current value of the charging current received by the high-voltage DC circuit is less than a preset current threshold, or the duration between the current moment and the moment the current adjustment command is sent is greater than a preset power-off duration.

[0010] Optionally, the clustering conditions include: The second difference between the current second voltage and the current lowest first voltage is less than a preset second threshold. Alternatively, within a preset time period, the second difference is always greater than or equal to the preset second threshold and less than the preset third threshold.

[0011] Optionally, the current attenuation coefficient is related to at least one of the following parameters: The number of second-generation battery clusters, battery formulation, and heat dissipation performance of the battery system.

[0012] Optionally, the rated upper limit of the charging current corresponding to the charger. It is related to the number of chargers and the charging mode performed by the chargers.

[0013] Optionally, the target current The following relationship must be satisfied:

[0014] in, α The current attenuation coefficient is... The current number of the second battery cluster, This is the minimum allowable charging current among the current allowable charging currents of each second battery cluster. , , For preset coefficients, Q The rated capacity of the multi-cluster power battery system F For battery formulation parameters, H These are the heat dissipation performance parameters of the battery system. This refers to the rated upper limit of the power supply current corresponding to the charger.

[0015] Optionally, before determining to enter the charging mode, the method further includes: Wake-up is achieved by receiving electrical energy from the charger via the auxiliary power line; Send a wake-up signal to the main controller.

[0016] Secondly, based on the same inventive concept, embodiments of the present invention also provide a battery management system, including a central controller, multiple main controllers, multiple battery clusters, and a high-voltage DC circuit; wherein: The main controller is connected to the charger and each main controller; The main controller is connected to each battery cluster in a one-to-one correspondence. For any given battery cluster, the battery cluster comprises a plurality of electrically connected individual cells; The main controller is used to implement the vehicle multi-cluster power battery system charging method as described in the first aspect through signaling interaction with each of the main controllers and the charger.

[0017] The beneficial effects of this invention are as follows: The vehicle multi-cluster power battery system charging method and battery management system provided in this invention have the following advantages: The charging method utilizes the BMS's central controller to monitor the first voltage of each first battery cluster to be charged in real time. When the first voltage difference between the first battery clusters is too large, the system automatically determines the timing and order of battery cluster access based on the voltage difference between the battery cluster to be charged and the second battery cluster currently being charged. This avoids the problem of some battery clusters being overcharged or undercharged due to simultaneous charging of multiple battery clusters, effectively achieving inter-cluster load balance, extending battery life, and improving system reliability. Furthermore, the entire process is achieved by the BMS central controller through interaction with other BMS controllers and the charger, eliminating the need for manual operation of battery cluster access or manual specification of the charging order, significantly lowering the barrier to entry and improving overall charging convenience and intelligence. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the battery management system provided in an embodiment of the present invention; Figure 2 This is one of the flowcharts for a vehicle multi-cluster power battery system charging method provided in an embodiment of the present invention; Figure 3 The second flowchart is a method for charging a multi-cluster power battery system for vehicles provided in an embodiment of the present invention. Figure 4 This is a flowchart of a vehicle multi-cluster power battery system discharge method according to an embodiment of the present invention. Detailed Implementation

[0019] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. However, the exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to make the present invention more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the figures denote the same or similar structures, and therefore repeated descriptions of them will be omitted. Terms describing position and direction in the present invention are illustrative based on the accompanying drawings, but changes can be made as needed, and all such changes are included within the scope of protection of the present invention. The accompanying drawings of the present invention are for illustrative purposes only and do not represent actual proportions.

[0020] It should be noted that specific details are set forth in the following description to provide a full understanding of the invention. However, the invention can be practiced in many ways other than those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below. The following description is a preferred embodiment for carrying out the present application; however, the description is for the purpose of illustrating the general principles of the application and is not intended to limit the scope of the application. The scope of protection of this application shall be determined by the appended claims.

[0021] The charging method and battery management system for a vehicle multi-cluster power battery system provided in the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0022] The technical solutions provided in the embodiments of the present invention can be applied to electric vehicles, such as battery electric vehicles (BEV), plug-in hybrid electric vehicles (PHEV), and extended-range electric vehicles (EREV). The embodiments of the present invention do not impose any further limitations on these vehicles.

[0023] First, the structure of the Battery Management System (BMS) provided in the embodiments of the present invention will be introduced. For example... Figure 1 As shown, the battery management system includes: a main controller M1, multiple main controllers M2, multiple battery clusters B, a high-voltage DC circuit L, a main charging switch component KS, a battery cluster high-voltage switch component KB, and an auxiliary power line ( Figure 1 Structures such as (not shown in the image). Among them: The main charging switch component KS is a switch used to control the on / off state of the electrical circuit between the high-voltage DC circuit L and the charger. In specific implementation, the main charging switch component KS includes a main charging positive switch component for controlling the on / off state of the electrical connection between the positive power line of the high-voltage DC circuit L and the charger, and a main charging negative switch component for controlling the on / off state of the electrical connection between the negative power line of the high-voltage DC circuit L and the charger.

[0024] The battery cluster high-voltage switch component KB is a switch used to control the on / off state of the electrical circuit between battery cluster B and high-voltage DC circuit L. In specific implementation, the battery cluster high-voltage switch component KB includes a battery cluster high-voltage positive switch component for controlling the on / off state of the electrical connection between battery cluster B and the positive power line of high-voltage DC circuit L, and a battery cluster high-voltage negative switch component for controlling the on / off state of the electrical connection between battery cluster B and the negative power line of high-voltage DC circuit L.

[0025] The main controller M1 is connected to the main charging switch component KS, each main controller M2, and the vehicle control unit (VCU).

[0026] The main controller M2 is connected to each battery cluster B in a one-to-one correspondence, and is also connected to the high-voltage switch component KB of the corresponding battery cluster B. The main controller M2 is used to monitor the status of the battery cluster B and report it to the main controller M1, and to control the on / off state of the corresponding high-voltage switch component KB to control the connection between the corresponding battery cluster B and the high-voltage DC circuit L.

[0027] For any given battery cluster B, battery cluster B includes multiple electrically connected individual cells B'. In specific implementations, the individual cells B' in battery cluster B can be configured with circuit structures as needed, for example, the individual cells B' can be connected in series and / or parallel to form battery cluster B. In addition, for any given battery cluster B, battery cluster B may also include a slave controller M3 connected one-to-one with each individual cell B'. The slave controller M3 is also connected to the master controller M2 corresponding to its respective battery cluster B. The slave controller M3 is used to monitor the status of the connected individual cells B' and report it to the master controller M2.

[0028] The auxiliary power cable is used to supply power to the main controller M1 and other structures.

[0029] In specific implementation, the high-voltage DC circuit L is a DC circuit with a voltage value of not less than 64V. It can be implemented using structures such as high-voltage boxes, combiner cabinets, and cables; however, this embodiment of the invention does not impose further limitations. The high-voltage DC circuit L is connected to the target vehicle-mounted load component F through a load high-voltage switch component KF. The load high-voltage switch component KF includes a load high-voltage positive switch component for controlling the electrical connection between the target vehicle-mounted load component F and the positive power line of the high-voltage DC circuit L, and a load high-voltage negative switch component for controlling the electrical connection between the target vehicle-mounted load component F and the negative power line of the high-voltage DC circuit L. The vehicle-mounted load component F includes a power system load component F1 and a non-power system load component F2. The power system load component F1 includes components such as motors that directly output vehicle driving power. The non-power system load component F2 includes components such as instruments, sensors, controllers (including VCUs), air conditioners, and vehicle infotainment systems that do not output vehicle driving power. The main controller M1 connects the vehicle-mounted load component F to the high-voltage DC circuit L by controlling the load high-voltage control component KF corresponding to the vehicle-mounted load component F.

[0030] In specific implementation, the switching components (including the main charging switch component KS, the battery cluster high voltage switch component KB, the load high voltage switch component KF, etc.) can be implemented using structures such as junction field-effect transistors (JFETs), metal-oxide-semiconductor field-effect transistors (MOSFETs), insulated-gate bipolar transistors (IGBTs), relays, and contactors. The embodiments of the present invention do not impose too many limitations here.

[0031] The charging method for a vehicle multi-cluster power battery system provided by embodiments of the present invention will be described in detail below. Figure 2 As shown, the method is applied to the main controller and specifically includes the following steps: S100, Perform initialization operation.

[0032] Optionally, the initialization operation may include: waking up the device by receiving electrical energy from the charger via an auxiliary power line (e.g., the positive terminal of the auxiliary power line); and sending a wake-up signal to the main controller to wake it up. This allows the main controller to wake up the corresponding slave controllers of the battery cluster after being activated.

[0033] In the specific implementation process, according to the Chinese national standard GB / T 20234, the positive power line of the auxiliary power supply is the A+ power line. After the charger and the vehicle's charging port are fully connected and fully locked, the A+ power line can output a low-voltage current of positive 12V. After receiving the electrical energy output from the charger through the positive power line of the auxiliary power supply, the main controller achieves power-on wake-up. After the main controller is powered on and woken up, it controls the corresponding auxiliary power switch components of each main controller to close, so that each auxiliary power line provides power to the main controller. Then, the main controller sends a wake-up signal to each main controller to wake up the main controller. After that, the main controller sends a wake-up signal to each slave controller of the corresponding battery cluster to wake up the slave controller. Among them, the main controller and the slave controller can connect to the auxiliary power line through their respective corresponding auxiliary power switch components. The main controller wakes up the main controller by controlling the closing of the auxiliary power switch component corresponding to the main controller and then sending a wake-up signal to the main controller. The main controller wakes up the slave controller by closing the auxiliary power switch component corresponding to the slave controller and then sending a wake-up signal to the slave controller.

[0034] S101. After detecting the charging connection confirmation signal generated by the charger, confirm that you are entering the charging mode.

[0035] In the specific implementation process, according to the Chinese national standard GB / T 20234, after the charger is connected to the vehicle's charging port, the charger will apply a preset voltage signal to the CC2 signal line. The main controller can monitor the voltage signal transmitted on the CC2 signal line: when the charger and the vehicle's charging port are not fully connected or fully locked, the main controller will detect that the voltage signal transmitted on the CC2 signal line is an abnormal signal that does not meet the standard, and the main controller and the charger will prohibit entering the charging mode; when the charger and the vehicle's charging port are fully connected and fully locked, the main controller will detect that the voltage signal transmitted on the CC2 signal line is a charging connection confirmation signal that meets the standard, and based on this, the main controller determines to enter the charging mode.

[0036] S102. Obtain the first voltage of the corresponding first battery cluster from the main controller corresponding to each first battery cluster.

[0037] In this context, the first battery cluster, when in charging mode, is the battery cluster currently in a state of waiting to be charged. The first voltage is the total voltage of the corresponding first battery cluster. The first voltage is acquired by the main controller connected to the first battery cluster.

[0038] In practical implementation, the main controller can set a charging status flag for each battery cluster. Battery clusters that are not faulty and whose current charge level is below the rated charge level are marked as the first battery cluster in a waiting-to-charge state using the charging status flag. The main controller can use a polling method to query the current voltage of the corresponding battery cluster from the main controllers of all battery clusters, and determine the first voltage corresponding to the first battery cluster accordingly; or the main controller can query the first voltage of the corresponding first battery cluster from the main controllers of all first battery clusters. This embodiment of the invention does not impose further limitations here.

[0039] S103. Determine the relationship between the first difference between the highest and lowest first voltages among the current first voltages and the target threshold.

[0040] If the first difference is greater than the target threshold, then proceed to step S104.

[0041] S104. Send a clustering command to the main controller corresponding to the lowest first voltage, so that the main controller responds to the clustering command by connecting the first battery cluster corresponding to the lowest first voltage as the first second battery cluster to the high voltage DC circuit.

[0042] For example, there are currently four first battery clusters B1, B2, B3, and B4, with corresponding first voltages of: B1: 5.52V, B2: 6.75V, B3: 8.86V, and B4: 11.35V. Then, the first difference... If the target threshold is 5V, then the main controller M1 sends a clustering command to the main controller M2-1 corresponding to the first battery cluster B1, and the main controller M2-1 connects the first battery cluster B1 to the high-voltage DC circuit.

[0043] For ease of understanding, in this embodiment of the invention, the battery cluster connected to the high-voltage DC circuit is referred to as the second battery cluster.

[0044] S105. After confirming that the first second battery cluster has been connected to the high-voltage DC circuit, close the main charging switch component corresponding to the high-voltage DC circuit and send a charging ready message to the charger. Then, receive the charging current output by the charger in response to the charging ready message through the high-voltage DC circuit to charge the first second battery cluster.

[0045] In practice, according to the Chinese national standard GB / T 27930, the charging ready message can be a BRO=0xAA message to notify the charger to start outputting current for charging.

[0046] In specific implementation, to enable the use of non-power system load components (such as instruments, sensors, vehicle control units (VCU), air conditioning, vehicle infotainment systems, etc.) during vehicle charging, the charger can directly supply power to the non-power system load components without powering them through the power battery. Optionally, before closing the main charging switch corresponding to the high-voltage DC circuit, the non-power system load components can be connected to the high-voltage DC circuit. After confirming successful connection, the main charging switch corresponding to the high-voltage DC circuit is then closed. The non-power system load components can control the electrical circuit connection to the high-voltage DC circuit through their corresponding load high-voltage switches. The main controller can directly control the closing of the load high-voltage switches corresponding to the non-power system load components; alternatively, it can send control commands to the controllers corresponding to the load high-voltage switches, allowing other controllers to indirectly control the closing of the load high-voltage switches corresponding to the non-power system load components. This embodiment of the invention does not impose further limitations. In this embodiment of the invention, the order in which the operation of controlling the non-power system load components to connect to the high-voltage DC circuit and the operation of sending a clustering command to the main controller corresponding to the lowest first voltage to realize the connection of the first second battery cluster to the high-voltage DC circuit are not limited. For example, the two can be executed simultaneously in parallel.

[0047] In the specific implementation process, after the main controller determines that it has entered the charging mode, it can periodically send a charging preparation not ready message to the charger (according to the Chinese national standard GB / T 27930, the charging preparation not ready message can be a BRO=0x00 message). Within a specified period of time from the first sending of the charging preparation not ready message, it controls the non-power system load components to connect to the high-voltage DC circuit, and sends a clustering command to the main controller corresponding to the lowest first voltage to realize the first second battery cluster connecting to the high-voltage DC circuit. If the above operations are not completed within the specified period of time from the first sending of the charging preparation not ready message, the charging process is terminated.

[0048] S106. Determine if there is a second charging cluster that is currently charging.

[0049] If a second charging cluster is currently charging, proceed to step S107. If no second charging cluster is currently charging, proceed to step S113.

[0050] S107. Acquire the second voltage. The second voltage is the total voltage of the overall circuit structure composed of all the second battery clusters.

[0051] In practice, the main controller can measure the voltage on the combiner side at the combiner cabinet or other structures in the high-voltage DC circuit as the second voltage.

[0052] S108. Determine whether the current second voltage and the lowest first voltage among the current first voltages satisfy the clustering condition.

[0053] If the clustering condition is met, proceed to step S109; if the clustering condition is not met, proceed to step S113.

[0054] Optionally, clustering conditions include: (1) The second difference between the current second voltage and the current lowest first voltage is less than the preset second threshold.

[0055] (2) Within a preset time period, the second difference between the current second voltage and the current lowest first voltage is always greater than or equal to the preset second threshold and less than the preset third threshold.

[0056] Preferably, the preset second threshold can be set to 3V; the preset third threshold can be set to 6V; and the preset duration can be set to 500ms.

[0057] Alternatively, if the second difference between the current second voltage and the current lowest first voltage is greater than a preset third threshold, an alarm message indicating an abnormal charging status can be issued to remind the user to check if the vehicle has malfunctioned.

[0058] S109. Send a clustering command to the main controller corresponding to the current lowest first voltage, so that the main controller responds to the clustering command by connecting the first battery cluster corresponding to the current lowest first voltage as a new second battery cluster to the high voltage DC circuit for charging.

[0059] For example, there are currently two first battery clusters B3 and B4, and two second battery clusters B1 and B2. The first voltage corresponding to the first battery clusters is: first battery cluster B3: 8.86V, first battery cluster B4: 11.35V; the second voltage corresponding to the second battery clusters B1 and B2 as a whole is 9.1V. The second difference is then... If the second threshold is preset to 3V, then the clustering condition is met. The main controller will send a clustering command to the main controller M2-3 corresponding to the first battery cluster B3, and the main controller M2-3 will connect the first battery cluster B3 to the high voltage DC circuit.

[0060] During the charging of the second battery cluster using the high-voltage DC circuit, the charging current needs to be configured to ensure safety. Accordingly, whenever the number of the second battery clusters changes (e.g., when steps S105, S109, and steps S112, S205, S212 mentioned later are executed), the following steps are also included (not shown in the figure): The target current is determined based on the minimum allowable charging current of each second battery cluster, the current number of second battery clusters, the rated capacity of the multi-cluster power battery system, the current decay coefficient, and the rated upper limit of the charging current corresponding to the charger. A charging parameter request message indicating the target current is sent to the charger. This enables the charger to respond to the charging parameter request message and supply power to the high-voltage DC circuit with the target voltage and target current.

[0061] The target voltage is the rated voltage of the battery cluster. In practice, the specific value of the rated voltage of the battery cluster can be set according to its specifications. For example, if the battery cluster consists of 12 individual cells connected in parallel through 4 parallel branches, with each parallel branch including 3 individual cells connected in series, then the rated voltage of the battery cluster can be determined to be 3 times the rated voltage of the individual cells.

[0062] In practical implementation, the current attenuation coefficient α It can be a preset fixed value or a variable value determined based on the current situation.

[0063] Furthermore, optionally, the current attenuation coefficient α It is related to at least one of the following parameters: The number of second-generation battery clusters, battery formulation, and heat dissipation performance of the battery system.

[0064] Alternatively, the rated upper limit of the power supply current corresponding to the charger. It is related to the number of chargers and the charging mode performed by the chargers.

[0065] For example, when the charger uses the national standard charging mode, regardless of the number of chargers connected to the vehicle's high-voltage DC circuit, the total rated upper limit of the charging current for all chargers will remain the same. The current is always a preset fixed value (e.g., 400A). If there are multiple chargers, the sum of the target currents for each charger should not exceed the total rated upper limit of the charging current for all chargers. (For example, if the total rated upper limit of the power supply current corresponding to all chargers is 400A, and the number of chargers connected to the vehicle's high-voltage DC circuit is 4, then the rated upper limit of the power supply current corresponding to a single charger is...) =100A). When the charger uses a specific charging mode that is not a national standard (e.g., a group standard), the rated upper limit of the power supply current for a single charger can be a preset fixed value (e.g., 100A). (400A) The total rated upper limit of the charging current for all chargers can be the sum of the rated upper limit of the power supply current for each charger (e.g., the rated upper limit of the charging current for a single charger). If there are 4 chargers connected to the vehicle's high-voltage DC circuit, the total rated upper limit of the power supply current for all chargers is 1600A.

[0066] In one alternative implementation, the target current... The following methods can be used to determine this:

[0067] in, α The current attenuation coefficient is... The current number of the second battery cluster, This is the minimum allowable charging current among the current allowable charging currents of each second battery cluster. For preset coefficients, Q The rated capacity of the multi-cluster power battery system (i.e., the total charge corresponding to all battery clusters, measured in coulombs (C) or ampere-hours (A·h). Preferably, .

[0068] An alternative implementation method, current attenuation coefficient α Determined in the following manner:

[0069] in, , These are preset coefficients. FThese are battery formulation parameters, and specific values ​​can be set according to the formulation of the power battery, such as the battery formulation parameters for lithium iron phosphate batteries and ternary lithium batteries. F different. H These are the heat dissipation performance parameters of the battery system, which can be calibrated and determined based on the actual heat dissipation performance of the battery system. This refers to the current number of the second battery clusters. The current attenuation coefficient is set when the current number of the second battery clusters is greater than 1. α The current decay coefficient corresponding to the number of the current second battery cluster being less than 1 α This is to suppress the circulating current phenomenon in the high-voltage DC circuit caused by the voltage imbalance of different second battery clusters, and to reduce the thermal effect generated by the high-voltage DC circuit when charging the battery clusters with high current. Preferably, , .

[0070] In this way, the target current for charging the second battery cluster by the high-voltage DC circuit determined in the above manner can protect the second battery cluster with the minimum allowable charging current and prevent overcharging of the second battery cluster.

[0071] Furthermore, during the charging process of each second battery cluster connected to the high-voltage DC circuit, when any of the second battery clusters reaches full charge and needs to terminate charging, there is a safety risk in directly disconnecting the electrical connection between the second battery cluster (hereinafter referred to as the third battery cluster) and the high-voltage DC circuit because the target current of the high-voltage DC circuit charging the connected second battery cluster is relatively large. Therefore, the following steps can be used to disconnect the third battery cluster from the charging circuit: S110. Determine whether there is a third battery cluster in each of the current second battery clusters that has reached the full charge condition.

[0072] If a third battery cluster exists in the second battery cluster, proceed to step S111; if a third battery cluster does not exist in the second battery cluster, proceed to step S113.

[0073] Optionally, the full charge conditions include: the current voltage of the battery cluster reaching the preset full charge voltage corresponding to the battery cluster; or, the current charge level of the battery cluster reaching the preset full charge capacity corresponding to the battery cluster; or, receiving a full charge command indicating that the battery cluster has reached a full charge state. For example, for any second battery cluster, if it is determined that the current voltage of the second battery cluster reaches the preset full charge voltage corresponding to the second battery cluster, the second battery cluster is determined to be the third battery cluster. As another example, the charger, in response to a user's operation (e.g., manually swiping a magnetic card), generates a full charge command indicating that a specified second battery cluster has reached a full charge state and sends it to the BMS. After receiving the full charge command, the main controller determines that the specified second battery cluster is the third battery cluster.

[0074] S111. Send a current adjustment command to the charger requesting the charger to adjust the current value of the charging current output to the high-voltage DC circuit to the rated minimum current value of the charger.

[0075] Preferably, the rated minimum current value of the charger can be set to 5A.

[0076] S112. When it is determined that the power-off conditions are met, a de-cluster command is sent to the main controller corresponding to the third battery cluster, so that the main controller disconnects the third battery cluster from the high-voltage DC circuit in response to the de-cluster command.

[0077] The power-off conditions include: the current value of the charging current received by the high-voltage DC circuit is less than the preset current threshold, or the duration between the current moment and the moment the current adjustment command is sent is greater than the preset power-off duration.

[0078] Preferably, the preset current threshold can be set to 15A or a lower current value to avoid the safety risks caused by high-voltage DC circuits switching on and off under high current conditions.

[0079] Furthermore, after all battery clusters have been charged and de-clusted, to ensure safety, a similar procedure to the de-clusting operation can be used to disconnect the electrical connections between the charger and the high-voltage DC circuit, and between the high-voltage DC circuit and the target vehicle load components: S113. Determine whether the charging end condition is met.

[0080] If the charging end condition is met, proceed to step S114; otherwise, return to step S106.

[0081] Optionally, the charging termination conditions include: when the third battery cluster is disconnected from the high-voltage DC circuit, it is determined that there is no second battery cluster currently connected to the high-voltage DC circuit for charging; or, a charging termination command is received; or, it is determined that the second battery cluster has experienced a fault of a preset fault category and / or preset fault level.

[0082] For example, the charger generates a charging end command in response to the user's operation (such as manually swiping a magnetic card) and sends it to the BMS. After receiving the charging end command, the main controller determines that the charging end conditions are met.

[0083] Furthermore, if it is determined that the first battery cluster has experienced a fault of a preset fault category and / or preset fault level, triggering the charging termination condition, the main controller can also report the fault category and / or fault level to the VCU.

[0084] S114. Send a current adjustment command to the charger requesting the charger to adjust the current value of the charging current output to the high-voltage DC circuit to the rated minimum current value of the charger.

[0085] S115. When the power-off conditions are met, disconnect the main charging switch. After confirming that the main charging switch is disconnected, exit the charging mode and disconnect the components connected to the high-voltage DC circuit from the high-voltage DC circuit.

[0086] The power-off conditions include: the current value of the charging current received by the high-voltage DC circuit is less than the preset current threshold, or the duration between the current moment and the moment the current adjustment command is sent is greater than the preset power-off duration.

[0087] Among these components, those already connected to the high-voltage DC circuit include at least non-power system load components. Furthermore, if, while the second battery cluster is being charged via the high-voltage DC circuit but has not yet completed charging, a charging termination command is received, and the electrical connection between the high-voltage DC circuit and the main charging switch is disconnected, then the components already connected to the high-voltage DC circuit also include the second battery cluster currently connected to the high-voltage DC circuit.

[0088] In the specific implementation process, if the high-voltage DC circuit also contains switching components that can control the on and off of electrical circuits (such as combiner cabinets), then after determining to exit the charging mode, the main controller can also control the switching components that can control the on and off of electrical circuits contained in the high-voltage DC circuit to disconnect.

[0089] In practice, to facilitate the VCU's management of the vehicle battery status, when the main controller determines that the power-off conditions are met, it can first report an exit charging mode request command to the VCU. In response to the exit charging mode request command, the VCU sends an exit charging mode permission command to the main controller. After receiving the exit charging mode permission command, the main controller disconnects the main charging switch component.

[0090] In specific implementation, after the main controller performs the operation to disconnect the main charging switch component, it can determine that the main charging switch component is disconnected after acquiring sensor information confirming that the main charging switch component is disconnected; or, the main controller can determine that the main charging switch component is disconnected after a preset first timeout period (e.g., 5 seconds) following the operation to disconnect the main charging switch component. Similarly, after the main controller controls a component connected to the high-voltage DC circuit to disconnect from the high-voltage DC circuit, it can determine that the corresponding component is disconnected after acquiring sensor information confirming that the corresponding component is disconnected; or, the main controller can determine that the corresponding component is disconnected after a preset second timeout period (e.g., 5 seconds) following the operation to disconnect the corresponding component.

[0091] Furthermore, after completing all the above steps, the main controller can also stop sending wake-up signals to the master controller once the wake-up source provided by the auxiliary power line disappears, thus causing the master controller to stop sending wake-up signals to the slave controllers. Finally, the main controller saves the monitoring data from this charging process and enters sleep mode.

[0092] Thus, the vehicle multi-cluster power battery system charging method provided by this invention, through the real-time monitoring of the first voltage of each first battery cluster to be charged by the BMS master controller, automatically decides the timing and order of battery cluster access based on the voltage difference between the battery cluster to be connected for charging and the second battery cluster currently being charged when the first voltage of each first battery cluster differs too much. This avoids the problem of some battery clusters being overcharged or undercharged due to simultaneous charging of multiple battery clusters, effectively achieving inter-cluster load balance, extending battery life, and improving system reliability. Furthermore, the entire process is achieved by the BMS master controller through interaction with other BMS controllers and the charger, eliminating the need for manual operation of battery cluster access or manual specification of the charging order, significantly lowering the barrier to entry and improving overall charging convenience and intelligence. Moreover, this solution is compatible with currently implemented national standards, facilitating engineering-scale application.

[0093] Optionally, such as Figure 3 As shown, in step S103, if it is determined that the first difference is less than or equal to the target threshold, the following steps can be performed: S204. In accordance with the order of the first voltage from low to high, send the clustering command to the corresponding main controller in sequence, so that the main controller responds to the clustering command and connects the corresponding first battery cluster as the second battery cluster to the high voltage DC circuit.

[0094] For example, there are currently four first battery clusters B1, B2, B3, and B4, with corresponding first voltages of: B1: 5.52V, B2: 6.75V, B3: 8.86V, and B4: 9.12V. Then the first difference... If the target threshold is 5V, then the main controller M1 sends a clustering command to the main controller M2-1 corresponding to the first battery cluster B1, and the main controller M2-1 connects the first battery cluster B1 to the high-voltage DC circuit; then the main controller M1 sends a clustering command to the main controller M2-2 corresponding to the first battery cluster B2, and the main controller M2-2 connects the first battery cluster B2 to the high-voltage DC circuit; then the main controller M1 sends a clustering command to the main controller M2-3 corresponding to the first battery cluster B3, and the main controller M2-3 connects the first battery cluster B3 to the high-voltage DC circuit; finally, the main controller M1 sends a clustering command to the main controller M2-4 corresponding to the first battery cluster B4, and the main controller M2-4 connects the first battery cluster B4 to the high-voltage DC circuit.

[0095] S205. After confirming that all second battery clusters are connected to the high-voltage DC circuit, close the main charging switch corresponding to the high-voltage DC circuit and send a charging ready message to the charger. Then, receive the charging current output by the charger in response to the charging ready message through the high-voltage DC circuit to charge all second battery clusters.

[0096] S206. Determine whether there is a second charging cluster that is currently charging.

[0097] If a second charging cluster is currently charging, proceed to step S207. If no second charging cluster is currently charging, proceed to step S213.

[0098] S207. Acquire the second voltage. The second voltage is the total voltage of the overall circuit structure composed of all the second battery clusters.

[0099] S210. Determine whether there is a third battery cluster in each of the current second battery clusters that has reached the full charge condition.

[0100] If a third battery cluster exists in the second battery cluster, proceed to step S211; if a third battery cluster does not exist in the second battery cluster, proceed to step S213.

[0101] Optionally, the full charge conditions include: the current voltage of the battery cluster reaches the preset full charge voltage corresponding to the battery cluster; or, the current charge of the battery cluster reaches the preset full charge capacity corresponding to the battery cluster; or, a full charge command indicating that the battery cluster has reached a full charge state is received.

[0102] S211. Send a current adjustment command to the charger requesting the charger to adjust the current value of the charging current output to the high-voltage DC circuit to the rated minimum current value of the charger.

[0103] S212. When it is determined that the power-off conditions are met, a de-cluster command is sent to the main controller corresponding to the third battery cluster, so that the main controller disconnects the third battery cluster from the high-voltage DC circuit in response to the de-cluster command.

[0104] The power-off conditions include: the current value of the charging current received by the high-voltage DC circuit is less than the preset current threshold, or the duration between the current moment and the moment the current adjustment command is sent is greater than the preset power-off duration.

[0105] S213. Determine whether the charging end condition is met.

[0106] If the charging end condition is met, proceed to step S114; if the charging end condition is not met, return to step S206.

[0107] Optionally, the charging termination conditions include: when the third battery cluster is disconnected from the high-voltage DC circuit, it is determined that there is no second battery cluster currently connected to the high-voltage DC circuit for charging; or, a charging termination command is received; or, it is determined that the second battery cluster has experienced a fault of a preset fault category and / or preset fault level.

[0108] In the specific implementation process, the specific implementation method of the charging step after determining that the first difference is less than or equal to the target threshold is roughly the same as the specific implementation method of the charging step after determining that the first difference is greater than the target threshold. The only difference is that the process of connecting the first battery cluster to the high voltage DC circuit is different. The other specific implementation methods can be referred to the corresponding implementation in the previous text, and will not be repeated here.

[0109] Through the above steps, when the first voltages of each first battery cluster are not significantly different, parallel charging can be performed directly. During the parallel charging process, dynamic decommissioning of charging clusters that have reached full charge conditions can be achieved, which can effectively improve charging efficiency.

[0110] In the above method, the target threshold used in step S103 is used to determine how the vehicle controls the battery cluster to connect to the high-voltage DC circuit for charging. The target threshold can be a preset fixed value (e.g., 5V) set according to actual needs; alternatively, it can be a dynamically adjusted variable value, taking into account the state differences that may occur with battery cluster usage time, and ensuring the safety of the battery clustering process under different impedances, temperatures, and battery aging levels. If the target threshold is a dynamically adjusted variable value, it can be specifically determined in the following way: If the target threshold is obtained for the first time, the target threshold will be a preset initial value; If this is not the first time the target threshold has been obtained, the target threshold is determined as follows: When the difference between the highest and lowest first voltages among the first voltages was determined to be less than or equal to the target threshold in the previous test, the instantaneous maximum current value generated between the battery cluster and the high-voltage DC circuit was collected when the battery cluster was connected to the high-voltage DC circuit. If it was determined that there was no instantaneous maximum current value greater than the preset instantaneous current threshold, the target threshold was kept unchanged. If it was determined that there was an instantaneous maximum current value greater than the preset instantaneous current threshold, the value of the target threshold was adjusted as the updated target threshold.

[0111] Optionally, each time the target threshold value is adjusted, the value of the target threshold increased by a preset step size can be used as the pending target threshold. If the pending target threshold is not greater than the upper limit of the target threshold, the pending target threshold is used as the updated target threshold; if the pending target threshold is greater than the upper limit of the target threshold, the upper limit of the target threshold is used as the updated target threshold. Alternatively, each time the target threshold value is adjusted, the value of the target threshold decreased by a preset step size can be used as the pending target threshold. If the pending target threshold is not less than the lower limit of the target threshold, the pending target threshold is used as the updated target threshold; if the pending target threshold is less than the lower limit of the target threshold, the lower limit of the target threshold is used as the updated target threshold.

[0112] In practice, the target threshold can be stored in the non-volatile memory of the main controller and maintained and updated as a variable. For example, the target threshold can be stored in the electrically erasable programmable read-only memory (EEPROM) of the main controller and updated and maintained as a variable.

[0113] In specific implementation, when the first difference between the highest and lowest first voltages among the previously determined first voltages is less than or equal to the target threshold, the process of connecting the battery cluster to the high-voltage DC circuit includes the process of connecting the battery cluster to the high-voltage DC circuit for charging, as detailed above (i.e., the first battery cluster corresponding to the first voltage is a battery cluster in a waiting-to-charge state when in charging mode), and may also include the process of connecting the battery cluster and the target vehicle load component (including non-power system load components and power system load components) to the high-voltage DC circuit when the vehicle is not electrically connected to the charger, so that the battery cluster supplies power to the target vehicle load component (i.e., the first battery cluster corresponding to the first voltage is a battery cluster in a discharging state when in discharging mode). Optionally, as... Figure 4 As shown, the battery pack and the target vehicle-mounted load component are connected to a high-voltage DC circuit. The process of supplying power from the battery pack to the target vehicle-mounted load component may include the following steps: S300, Perform discharge initialization operation.

[0114] Optionally, the discharge initialization operation may include: the main controller responding to a vehicle start command (e.g., an ON command) by receiving power from the auxiliary power supply via the auxiliary power line to wake up. After the main controller is powered on and woken up, it controls the corresponding auxiliary power switch of each main controller to close, so that each auxiliary power line provides power to the main controller. Then, the main controller sends a wake-up signal to each main controller to wake up the main controller. After waking up, the main controller sends a wake-up signal to each slave controller of the corresponding battery cluster to wake up the slave controller. The main controller and slave controller can be connected to the auxiliary power line through their respective auxiliary power switch. The main controller wakes up the main controller by controlling the closure of the auxiliary power switch corresponding to the main controller and sending a wake-up signal to the main controller. The main controller wakes up the slave controller by closing the auxiliary power switch corresponding to the slave controller and sending a wake-up signal to the slave controller. After both the main controller and slave controller have completed waking up, a fault self-check is performed. The fault self-check specifically includes at least one of the following: checking whether the high-voltage interlock mechanism is normal, checking whether the auxiliary power supply is normal (e.g., whether the output voltage of the auxiliary power supply is normal), and checking whether each battery cluster is normal through the main controller and slave controller (e.g., whether the current voltage of the battery cluster is normal, whether the temperature of the battery cluster is normal, etc.). During the fault self-check process, the main controller can periodically report a message to the VCU that the BMS is in the initialization self-check state, and after the fault self-check passes, the main controller reports a message to the VCU that the BMS self-check is complete; if the fault self-check fails, the main controller reports a fault status message to the VCU, and the fault message carries information such as the specific fault type (e.g., fault code) and fault level.

[0115] S301, Confirm entry into discharge mode.

[0116] Once the discharge initialization operation is completed and all fault self-tests pass, the system will enter discharge mode.

[0117] S302. Obtain the first voltage of the corresponding first battery cluster from the main controller corresponding to each first battery cluster.

[0118] In this context, the first battery cluster, when in discharge mode, is the battery cluster currently in a dischargeable state. The first voltage is the total voltage of the corresponding first battery cluster.

[0119] S303. Determine the relationship between the first difference between the highest and lowest first voltages among the current first voltages and the target threshold.

[0120] If the first difference is less than or equal to the target threshold, then proceed to step S401.

[0121] S401. Send clustering commands to the corresponding main controllers in order of increasing first voltage, so that each main controller responds to the clustering command and connects the corresponding first battery cluster as the second battery cluster to the high voltage DC circuit.

[0122] In the specific implementation process, the main controller controls the closing of the high-voltage switch component of the corresponding second battery cluster to achieve electrical connection between the second battery cluster and the high-voltage DC circuit.

[0123] S402. Once it is determined that all second battery clusters have been connected to the high-voltage DC circuit, a command to allow high voltage to be applied to the load is sent to the VCU.

[0124] S403: Receive the load high-voltage power-on command sent by the VCU in response to the load high-voltage power-on command, and control the target vehicle load component indicated by the load high-voltage power-on command to connect to the high-voltage DC circuit. This allows the second battery pack to supply power to the target vehicle load component through the high-voltage DC circuit.

[0125] In specific implementation, the load high voltage power-on command can be used to instruct the main controller to connect a single target vehicle load component to a high voltage DC circuit, or it can be used to instruct the main controller to connect a component group consisting of multiple target vehicle load components to a high voltage DC circuit. This embodiment of the invention does not impose any further limitations here.

[0126] By taking the above steps, when controlling the multi-cluster battery system to discharge to the target vehicle load component, the first voltage of all first battery clusters in the dischargeable state is detected, and all battery clusters are controlled to discharge to the target vehicle load component only when the difference between the first voltages is not large. This avoids problems such as circulating current and electrical shock caused by excessive voltage differences between battery clusters, and ensures the safety, reliability and battery life of the multi-cluster power battery system.

[0127] Optionally, in step S303, if the first difference is greater than the target threshold, then step S500 and / or step S501 are executed.

[0128] The S500 sends an alarm message to the user indicating an abnormal battery pack status. This reminds the user to check for vehicle malfunctions and provides troubleshooting suggestions, such as suggesting that the user try charging the battery pack for repairs.

[0129] S501. Determine whether the forced discharge conditions are met.

[0130] If the forced discharge conditions are met, proceed to step S502.

[0131] In specific implementation, the forced discharge condition can be the receipt of a forced discharge mode message. This forced discharge mode message can be automatically triggered by vehicle controllers such as the VCU based on driving control logic (e.g., autonomous driving logic), or it can be triggered based on user operation. Furthermore, a forced discharge mode message can be generated based on user operation and directly sent to the main controller; alternatively, a forced discharge command can be triggered based on user operation and sent to the VCU. The VCU then generates a forced discharge mode message based on the user-triggered forced discharge command and sends it to the main controller. The method by which the user triggers the forced discharge mode message / forced discharge command can be configured according to actual needs. For example, when a first difference is determined to be greater than a target threshold, the vehicle displays a prompt on the instrument panel asking the user whether to activate the forced discharge mode. The user then generates a forced discharge mode message / forced discharge command by triggering a confirmation operation on the instrument panel and sends it to the VCU. Alternatively, when a first difference is determined to be greater than a target threshold, the vehicle displays a prompt on the instrument panel asking the user whether to activate the forced discharge mode. The forced discharge mode message / forced discharge command is generated and sent to the VCU based on the user's operation on the vehicle's driving control components (e.g., pressing the accelerator pedal). This embodiment of the invention does not impose further limitations.

[0132] S502, Confirm entry into forced discharge mode.

[0133] S503. Send a power-on command to the main controller corresponding to the highest first voltage. This causes the main controller corresponding to the highest first voltage to respond to the power-on command and control the first battery cluster corresponding to the highest first voltage to be connected to the high-voltage DC circuit as the second battery cluster.

[0134] S504. If it is determined that the second battery cluster corresponding to the highest first voltage has been connected to the high-voltage DC circuit, a command to allow high voltage to be applied to the load is sent to the VCU.

[0135] S505: Receive the load high-voltage power-on command sent by the VCU in response to the load high-voltage power-on command, and control the target vehicle load component indicated by the load high-voltage power-on command to connect to the high-voltage DC circuit. This allows the second battery pack to supply power to the target vehicle load component through the high-voltage DC circuit.

[0136] Since the specific implementation methods of steps S504 and S505 are basically the same as those of steps S402 and S403 described above, they can be referred to the corresponding implementation methods in the previous text, and will not be repeated here.

[0137] In this way, when the difference in the first voltage of each first battery cluster in the vehicle's power battery system is too large to supply power to the vehicle through static parallel power supply, only the first battery cluster corresponding to the highest first voltage can be controlled as the second battery cluster to forcibly supply power to the vehicle. This allows the vehicle to still be powered even when the power battery clusters are abnormal, especially to provide power to the vehicle's power system load components to enable the vehicle to move (for example, if the second battery cluster corresponding to the highest first voltage is sufficient to provide the power required for normal vehicle operation, it can provide power for normal vehicle operation; or if the second battery cluster corresponding to the highest first voltage is insufficient to provide the power required for normal vehicle operation, it can provide energy to the power system load components to enable the vehicle to creep, facilitating emergency maneuvering to a parking position and improving the vehicle's emergency response capability).

[0138] In the process described above where the second battery cluster is statically connected to supply power to the vehicle in steps S401-S403, and in the process described above where the second battery cluster corresponding to the highest first voltage supplies power to the vehicle individually in steps S501-S505, when the battery cluster needs to stop supplying power to the vehicle, the voltage and current of the circuit loop formed between the high-voltage DC circuit and the electrically connected second battery cluster, and the target vehicle load component are both high. Directly performing the electrical disconnection action can easily generate electrical shocks such as arc discharge. To ensure safety, the power supply can be terminated in the following way: S601. Determine whether the discharge termination condition is met.

[0139] If the discharge termination condition is met, proceed to step S602; if the discharge termination condition is not met, continue the process of supplying power to the target vehicle load component through the high-voltage DC circuit using the second battery cluster.

[0140] In specific implementation, the discharge termination condition may include: receiving a discharge termination command sent by the VCU, or the second battery cluster supplying power to the target vehicle load component through the high-voltage DC circuit for a preset discharge duration, or determining that the current voltage of the second battery cluster has reached a lower voltage limit; or determining that the current charge level of the second battery cluster has reached a lower charge level. Furthermore, for forced discharge mode, if the user inserts the charger into the vehicle's charging port before exiting forced discharge mode, the vehicle may experience conflicting behavior where the second battery cluster discharges to the target vehicle load component and the charger charges the second battery cluster. Therefore, the discharge termination condition may also include: currently in forced discharge mode, and the main controller detects a charging connection confirmation signal generated by the charger.

[0141] The VCU can determine, based on user operation commands or autonomous driving control logic, that the second battery cluster needs to stop supplying power and send a discharge end command to the main controller; alternatively, the VCU can determine, based on the status information of the second battery clusters reported by the main controller, that there is a second battery cluster connected to the high-voltage DC circuit experiencing a fault of a preset fault level and / or preset fault category, and send a discharge end command to the main controller. Furthermore, in forced discharge mode, if the user inserts the charger into the vehicle's charging port without exiting forced discharge mode, the main controller can report an exit discharge end request to the VCU when it is in forced discharge mode and detects a charging connection confirmation signal generated by the charger. The VCU then sends a discharge end command to the main controller based on the discharge end request. This embodiment of the invention does not impose further limitations.

[0142] S602. Send a current adjustment command to the main controller corresponding to each second battery cluster. This causes each main controller to respond to the current adjustment command and control the corresponding second battery cluster to adjust the discharge current output to the high-voltage DC circuit to the rated minimum discharge value.

[0143] In practice, the minimum rated discharge value can be 0, or it can be a small current value that is not zero.

[0144] S603. When the power-down conditions are met, control each target vehicle-mounted load component to disconnect from the high-voltage DC circuit.

[0145] The power-off conditions include: the current value received by the high-voltage DC circuit is less than the preset current threshold, or the duration between the current moment and the moment the current adjustment command is sent is greater than the preset power-off duration.

[0146] Preferably, the preset current threshold can be set to a current value of 15A or lower.

[0147] S604. After confirming that each target vehicle-mounted load component is disconnected from the high-voltage DC circuit, a battery cluster power-off command is sent to each main controller. This causes each main controller to disconnect the corresponding second battery cluster from the high-voltage DC circuit in response to the battery cluster power-off command.

[0148] This avoids the safety risks associated with directly switching on and off high-voltage DC circuits under high current conditions.

[0149] Optionally, after determining that each second battery cluster has been disconnected from the high-voltage DC circuit, the main controller may report to the VCU the status information that each target vehicle load component and / or second battery cluster has been disconnected from the high-voltage DC circuit.

[0150] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0151] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to this application. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations 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, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0152] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0153] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0154] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A charging method for a vehicle multi-cluster power battery system, the method being applied to the main controller of a vehicle's battery management system (BMS); wherein the main controller is electrically connected to a charger, a main charging switch component of a high-voltage DC circuit, and multiple main controllers of the BMS, and each main controller is connected to a battery cluster in a one-to-one correspondence, and each battery cluster includes multiple electrically connected individual cells; The main charging switch component is a switch in the high-voltage DC circuit used to control the on / off state of the electrical circuit between the high-voltage DC circuit and the charger; Its features are, The method includes: After detecting the charging connection confirmation signal generated by the charger, it is determined to enter charging mode; After determining that the charging mode has been entered, if the first difference between the highest and lowest first voltages among the current first voltages is greater than a target threshold, a clustering command is sent to the main controller corresponding to the lowest first voltage. This causes the main controller to respond to the clustering command by connecting the first battery cluster corresponding to the lowest first voltage as the first second battery cluster to the high-voltage DC circuit. For any first voltage, the first voltage is the total voltage of the corresponding first battery cluster. When in the charging mode, the first battery cluster is the battery cluster currently in a state of waiting to be charged. The first voltage is acquired by the main controller connected to the first battery cluster. If it is determined that the first second battery cluster has been connected to the high-voltage DC circuit, then the main charging switch component corresponding to the high-voltage DC circuit is closed, and a charging ready message is sent to the charger; so as to receive the charging current output by the charger in response to the charging ready message through the high-voltage DC circuit and charge the first second battery cluster. When it is determined that a second battery cluster is being charged, whenever the clustering condition is met based on the current second voltage and the lowest first voltage among the current first voltages, a clustering command is sent to the main controller corresponding to the current lowest first voltage, so that the main controller responds to the clustering command and connects the first battery cluster corresponding to the lowest first voltage as a new second battery cluster to the high-voltage DC circuit for charging; wherein, the second voltage is the total voltage of the overall circuit structure composed of the second battery clusters collected by the main controller.

2. The method as described in claim 1, characterized in that, The method further includes: After determining that the charging mode has been entered, if the first difference between the highest and lowest first voltages among the current first voltages is less than or equal to the target threshold, then according to the order of the first voltages from low to high, the corresponding clustering command is sent to the corresponding main controller in sequence, so that the main controller responds to the clustering command and connects the corresponding first battery cluster as the second battery cluster to the high voltage DC circuit. If it is determined that all the second battery clusters have been connected to the high-voltage DC circuit, the main charging switch component corresponding to the high-voltage DC circuit is closed, and a charging ready message is sent to the charger; so as to receive the charging current output by the charger in response to the charging ready message through the high-voltage DC circuit and charge the second battery clusters.

3. The method as described in claim 1 or 2, characterized in that, The method further includes: Whenever the number of the second battery clusters changes, a target current is determined based on the minimum allowable charging current of each second battery cluster, the current number of the second battery clusters, the rated capacity of the multi-cluster power battery system, the current decay coefficient, and the rated upper limit of the charging current corresponding to the charger. A charging parameter request message is sent to the charger to indicate the target current, so that the charger responds to the charging parameter request message to supply power to the high voltage DC circuit with the target voltage and the target current. The target voltage is the rated voltage of the battery cluster.

4. The method as described in claim 3, characterized in that, The method further includes: When it is determined that there is a third battery cluster in each of the current second battery clusters that has reached the full charge condition, a current adjustment command is sent to the charger to request the charger to adjust the current value of the charging current output to the high voltage DC circuit to the rated minimum current value of the charger. When the power-off condition is determined to be met, a de-cluster command is sent to the main controller corresponding to the third battery cluster, so that the main controller disconnects the third battery cluster from the high-voltage DC circuit in response to the de-cluster command. The power-off conditions include: the current value of the charging current received by the high-voltage DC circuit is less than a preset current threshold, or the duration between the current moment and the moment the current adjustment command is sent is greater than a preset power-off duration.

5. The method as described in claim 1 or 2, characterized in that, Before the main charging switch component corresponding to the closed high-voltage DC circuit, the method further includes: It was determined that the non-power system load components were connected to the high-voltage DC circuit.

6. The method as described in claim 5, characterized in that, The method further includes: When the charging end condition is determined to be met, a current adjustment command is sent to the charger to request the charger to adjust the current value of the charging current output to the high voltage DC circuit to the rated minimum current value of the charger. When the power-off conditions are met, disconnect the main charging switch component; After confirming that the main charging switch component is open, the charging mode is exited, and the components that have been connected to the high-voltage DC circuit are disconnected from the high-voltage DC circuit; wherein, the components include the non-power system load components; The charging termination conditions include: whenever the number of the second battery clusters changes, determining that there are no second battery clusters currently being charged by the high-voltage DC circuit; or, receiving a charging termination command. The power-off conditions include: the current value of the charging current received by the high-voltage DC circuit is less than a preset current threshold, or the duration between the current moment and the moment the current adjustment command is sent is greater than a preset power-off duration.

7. The method as described in claim 1, characterized in that, The clustering conditions include: The second difference between the current second voltage and the current lowest first voltage is less than a preset second threshold. Alternatively, within a preset time period, the second difference is always greater than or equal to the preset second threshold and less than the preset third threshold.

8. The method as described in claim 3, characterized in that, The current attenuation coefficient is related to at least one of the following parameters: The number of second-generation battery clusters, battery formulation, and heat dissipation performance of the battery system.

9. The method as described in claim 3, characterized in that, The rated upper limit of the charging current corresponding to the charger It is related to the number of chargers and the charging mode performed by the chargers.

10. The method as described in claim 3, characterized in that, Target current The following relationship must be satisfied: in, α The current attenuation coefficient is... The current number of the second battery cluster, This is the minimum allowable charging current among the current allowable charging currents of each second battery cluster. , , For preset coefficients, Q The rated capacity of the multi-cluster power battery system F For battery formulation parameters, H These are the heat dissipation performance parameters of the battery system. This refers to the rated upper limit of the power supply current corresponding to the charger.

11. The method as described in claim 1, characterized in that, Before determining to enter the charging mode, the method further includes: Wake-up is achieved by receiving electrical energy from the charger via the auxiliary power line; Send a wake-up signal to the main controller.

12. A battery management system, characterized in that, Includes a central controller, multiple main controllers, multiple battery clusters, and a high-voltage DC circuit; among which: The main controller is connected to the charger and each main controller; The main controller is connected to each battery cluster in a one-to-one correspondence. For any given battery cluster, the battery cluster comprises a plurality of electrically connected individual cells; The main controller is used to implement the vehicle multi-cluster power battery system charging method as described in any one of claims 1-11 through signaling interaction with each of the main controllers and the charger.

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