Vehicle multi-cluster power battery system control method and battery management system

Abstract

The vehicle multi-cluster power battery system control method and the battery management system provided by the embodiment of the application are applied to the technical field of battery management, and include the following steps: after it is determined that the discharge mode is entered, if a first difference between a highest first voltage and a lowest first voltage in the current first voltages is less than or equal to a target threshold, a parallel instruction is sequentially sent to a corresponding main controller in a low-to-high order of the first voltages, the main controller is caused to connect a corresponding first battery cluster to a high-voltage direct-current circuit in response to the parallel instruction, the first voltage is a total voltage of the corresponding battery cluster, and the total voltage is collected by the corresponding connected main controller; it is determined that all the first battery clusters have been connected to the high-voltage direct-current circuit, and a high-voltage load permission instruction is sent to a VCU; a load high-voltage power-on instruction sent by the VCU in response to the high-voltage load permission instruction is received, and a target load component indicated by the load high-voltage power-on instruction is controlled to be connected to the high-voltage direct-current circuit; and the first battery cluster is caused to supply power to the target load component through the high-voltage direct-current circuit.

Description

TECHNICAL FIELD

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

[0002] At present, there is a power battery solution that adopts a multi-cluster battery system structure for electric vehicles to improve the endurance capability. However, since the multi-cluster battery system includes multiple battery clusters, the states of different battery clusters in the use process may be different. In the power-on and power-off control process of the power battery system, simultaneously controlling different states of the battery clusters to access the high-voltage direct current circuit may cause problems such as circulating current and electrical shock, which seriously affect the safety, reliability and battery life of the system. SUMMARY

[0003] The embodiments of the present application provide a vehicle multi-cluster power battery system control method and a battery management system to avoid problems such as circulating current and electrical shock caused by too large voltage difference of each battery cluster when discharging each battery cluster in the multi-cluster power battery system.

[0004] The embodiments of the present application provide a vehicle multi-cluster power battery system control method, which is applied to a general controller of a battery management system BMS of a vehicle; wherein the general controller is electrically connected with a vehicle control unit VCU and multiple master controllers of the BMS, the master controllers are connected with battery clusters one by one, and each battery cluster includes multiple electrically connected single batteries.

[0005] The method comprises:

[0006] After determining that the entering discharging mode, if the first difference between the highest first voltage and the lowest first voltage in the current first voltages is less than or equal to a target threshold, then the parallel cluster instruction is sequentially sent to the corresponding master controller in the order of the first voltage from low to high, so that the master controller responds to the parallel cluster instruction to access the high-voltage direct current circuit for the corresponding first battery cluster; wherein for any first voltage, the first voltage is the total voltage of the corresponding battery cluster in the dischargeable state, and the first voltage is obtained by the master controller connected with the battery cluster.

[0007] After determining that all the first battery clusters have accessed the high-voltage direct current circuit, the load high-voltage power-on instruction is sent to the VCU.

[0008] The load high-voltage power-on instruction sent by the VCU in response to the load high-voltage power-on instruction is received, and the target vehicle-mounted load component indicated by the load high-voltage power-on instruction is controlled to access the high-voltage direct current circuit; so that the first battery cluster supplies power to the target vehicle-mounted load component through the high-voltage direct current circuit.

[0009] Optionally, the method further comprises:

[0010] After determining that the first difference is greater than the target threshold value after entering the discharging mode, determining that a forced discharging condition is met, and sending a power-on instruction to the master controller corresponding to the highest first voltage, so that the master controller controls the first battery cluster corresponding to the highest first voltage to access the high-voltage direct current circuit in response to the power-on instruction;

[0011] After determining that the first battery cluster has accessed the high-voltage direct current circuit, sending a high-voltage load permission instruction to the VCU;

[0012] Receiving a load high-voltage power-on instruction sent by the VCU in response to the high-voltage load permission instruction, and controlling the target vehicle-mounted load component indicated by the load high-voltage power-on instruction to access the high-voltage direct current circuit, so that the first battery cluster supplies power to the target vehicle-mounted load component through the high-voltage direct current circuit.

[0013] Optionally, the method further comprises:

[0014] During the process that the first battery cluster supplies power to the target vehicle-mounted load component through the high-voltage direct current circuit, when a discharging end condition is met, sending a current adjustment instruction to the master controller corresponding to each first battery cluster, so that each master controller controls the corresponding first battery cluster to adjust the discharging current output to the high-voltage direct current circuit to a rated discharging minimum value in response to the current adjustment instruction;

[0015] When a power-down condition is met, controlling each target vehicle-mounted load component to be disconnected from the high-voltage direct current circuit;

[0016] After determining that each target vehicle-mounted load component is disconnected from the high-voltage direct current circuit, sending a battery cluster power-down instruction to each master controller, so that each master controller disconnects the corresponding first battery cluster from the high-voltage direct current circuit in response to the battery cluster power-down instruction.

[0017] Optionally, the target vehicle-mounted load component includes a power system load component and a non-power system load component;

[0018] The method further comprises:

[0019] During the process that the first battery cluster supplies power to the target vehicle-mounted load component through the high-voltage direct current circuit, if a charging connection confirmation signal generated by the charger is detected, a stop discharging instruction is sent to the master controller corresponding to each first battery cluster, so that each master controller controls the corresponding first battery cluster to stop discharging to the high-voltage direct current circuit in response to the stop discharging instruction;

[0020] sending a charging status message to the VCU for indicating that the charging connection confirmation signal is detected;

[0021] receiving a power system load component power-off instruction sent by the VCU in response to the charging status message, and controlling the power system load component to disconnect from the high-voltage direct current circuit;

[0022] after determining that the power system load component disconnects from the high-voltage direct current circuit, determining to enter a charging mode;

[0023] by signaling interaction with the charger, charging the first battery cluster through the high-voltage direct current circuit and supplying power to the non-power system load component through the high-voltage direct current circuit.

[0024] Optionally, the charging the first battery cluster through the high-voltage direct current circuit and supplying power to the non-power system load component through the high-voltage direct current circuit by signaling interaction with the charger comprises:

[0025] closing the total charging switch component corresponding to the high-voltage direct current circuit, and sending a charging preparation ready message to the charger; and receiving a power supply current output by the charger in response to the charging preparation ready message through the high-voltage direct current circuit to charge the first battery cluster and supply power to the non-power system load component.

[0026] Optionally, during the charging of the first battery cluster, the method further comprises:

[0027] when it is determined that there is a second battery cluster reaching a full charging condition in the current first battery clusters, sending a current adjustment instruction to the charger for requesting the charger to adjust a current value of the power supply current output to the high-voltage direct current circuit to a charger rated minimum current value;

[0028] when the power-off condition is met, sending a cluster withdrawal instruction to the main controller corresponding to the second battery cluster to make the main controller disconnect the second battery cluster from the high-voltage direct current circuit in response to the cluster withdrawal instruction.

[0029] Optionally, the method further comprises:

[0030] when the charging end condition is met, sending a current adjustment instruction to the charger for requesting the charger to adjust a current value of the power supply current output to the high-voltage direct current circuit to a charger rated minimum current value;

[0031] when the power-off condition is met, disconnecting the total charging switch component;

[0032] After determining that the total charging switch component is disconnected, it is determined to exit the charging mode, and the components connected to the high-voltage direct current circuit are disconnected and connected to the high-voltage direct current circuit respectively; wherein the components connected to the high-voltage direct current circuit at least include the non-power system load components.

[0033] The charging end condition includes: determining the first battery cluster not connected to the high-voltage direct current circuit whenever the number of the first battery cluster changes; or receiving a charging end instruction.

[0034] Optionally, during the charging of the second battery cluster, the method further comprises:

[0035] Whenever the number of the first battery cluster being charged changes, a target current is determined according to the minimum value of the allowed charging currents of the current first battery clusters, the current number of the first battery clusters, the rated capacity of the multi-cluster power battery system, a current attenuation coefficient, and a supply current upper limit value corresponding to the charger, a charging parameter request message indicating the target current is sent to the charger, so that the charger supplies power to the charging circuit at a target voltage and the target current in response to the charging parameter request message;

[0036] The target voltage is a battery cluster rated voltage.

[0037] Optionally, the current attenuation coefficient is related to at least one of the number of the first battery clusters, a battery formula, and a heat dissipation performance of the battery system.

[0038] Optionally, the supply current upper limit value corresponding to the charger is related to the number of the chargers and the charging mode performed by the chargers.

[0039] Optionally, the target current satisfies the following relationship:

[0040]

[0041]

[0042]

[0043] wherein, α is a current attenuation coefficient, is the current number of the first battery clusters, is the minimum allowed charging current of the allowed charging currents of the current first battery clusters, , , is a preset coefficient, Q is the rated capacity of the multi-cluster power battery system, Fa battery formula parameter, H a heat dissipation performance parameter of a battery system, a maximum supply current value corresponding to the charger.

[0044] Optionally, the power-off condition comprises that a current value received by the high-voltage direct-current circuit is less than a preset current threshold, or a time length from a current moment to a moment when the current adjustment instruction is sent is greater than a preset power-off time length.

[0045] Based on the same inventive concept, the embodiment of the present application also provides a battery management system, comprising a total controller, a plurality of main controllers, a plurality of battery clusters, and a high-voltage direct-current circuit; wherein:

[0046] the total controller is connected with the VCU and each main controller;

[0047] the main controller is connected with the battery cluster one by one;

[0048] for any battery cluster, the battery cluster comprises a plurality of electrically connected single batteries;

[0049] the total controller is used to realize the vehicle multi-cluster power battery system control method through signaling interaction between each main controller and the VCU.

[0050] The present application has the following advantages:

[0051] The vehicle multi-cluster power battery system control method and the battery management system provided by the embodiment of the present application can detect the first voltages of all battery clusters in a dischargeable state when the multi-cluster battery system discharges the target vehicle-mounted load component, and only control all battery clusters to discharge the target vehicle-mounted load component when the differences between the first voltages are small, so that the problems such as circulating current and electrical shock caused by too large voltage differences between the battery clusters can be avoided, and the safety, reliability and battery life of the multi-cluster power battery system are ensured. BRIEF DESCRIPTION OF DRAWINGS

[0052] Figure 1 a structural schematic diagram of the battery management system provided by the embodiment of the present application;

[0053] Figure 2 a flowchart of the vehicle multi-cluster power battery system control method provided by the embodiment of the present application;

[0054] Figure 3 a partial flowchart of the vehicle multi-cluster power battery system control method provided by the embodiment of the present application;

[0055] Figure 4 one of partial flowcharts of the vehicle multi-cluster power battery system charging method related to the embodiment of the present application;

[0056] Figure 5 This is a second partial flowchart of the charging method for a vehicle multi-cluster power battery system according to an embodiment of the present invention. Detailed Implementation

[0057] 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.

[0058] 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.

[0059] The following description, in conjunction with the accompanying drawings, details the vehicle multi-cluster power battery system control method and battery management system provided in the embodiments of the present invention.

[0060] The technical solutions provided in the embodiments of the present invention can be applied to vehicles powered by electric energy, 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 too many limitations here.

[0061] First, the structure of the Battery Management System (BMS) provided in the embodiments of the present invention will be introduced. For example... Figure 1As shown, the battery management system comprises: a total controller M1, a plurality of main controllers M2, a plurality of battery clusters B, a high-voltage direct current circuit L, a total charging switch component KS, a battery cluster high-voltage switch component KB, an auxiliary power supply line (not shown) and the like. Among them: Figure 1

[0062] The total charging switch component KS is a switch for controlling the on-off of the electrical circuit between the high-voltage direct current circuit L and the charger. In the specific implementation process, the total charging switch component KS comprises a total charging positive switch component for controlling the on-off of the electrical connection between the positive power supply line of the high-voltage direct current circuit L and the charger, and a total charging negative switch component for controlling the on-off of the electrical connection between the negative power supply line of the high-voltage direct current circuit L and the charger.

[0063] The battery cluster high-voltage switch component KB is a switch for controlling the on-off of the electrical circuit between the battery cluster B and the high-voltage direct current circuit L. In the specific implementation process, the battery cluster high-voltage switch component KB comprises a battery cluster high-voltage positive switch component for controlling the on-off of the electrical connection between the battery cluster B and the positive power supply line of the high-voltage direct current circuit L, and a battery cluster high-voltage negative switch component for controlling the on-off of the electrical connection between the battery cluster B and the negative power supply line of the high-voltage direct current circuit L.

[0064] The total controller M1 is connected with the total charging switch component KS, each main controller M2, and a vehicle control unit (VCU).

[0065] Each main controller M2 is connected with a corresponding battery cluster B, and the main controller M2 is connected with the battery cluster high-voltage switch component KB of the corresponding battery cluster B. The main controller M2 is used to monitor the state of the battery cluster B and report it to the total controller M1, and control the on-off of the corresponding battery cluster high-voltage switch component KB to control the connection between the corresponding battery cluster B and the high-voltage direct current circuit L.

[0066] For any battery cluster B, the battery cluster B comprises a plurality of electrically connected single batteries B'. In the specific implementation process, the single batteries B' in the battery cluster B can be provided with a circuit structure as needed, for example, the single batteries B' are connected in series and / or parallel to form the battery cluster B. In addition, for any battery cluster B, the battery cluster B can further comprise a slave controller M3 connected with each single battery B' in one-to-one correspondence, and the slave controller M3 is further connected with the main controller M2 corresponding to the battery cluster B. The slave controller M3 is used to monitor the state of the connected single battery B' and report it to the main controller M2.

[0067] The auxiliary power supply line is used to supply power to the total controller M1 and the like.

[0068] ​In the implementation process, the high-voltage direct-current circuit L is a direct-current circuit with a voltage value not less than 64 V, and can be implemented by using a high-voltage box, a busbar cabinet, a cable, etc. The embodiment of the present application does not make too many limitations here. The high-voltage direct-current circuit L is connected with the target vehicle 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 of the target vehicle load component F and the positive power line of the high-voltage direct-current circuit L, and a load high-voltage negative switch component for controlling the electrical connection of the target vehicle load component F and the negative power line of the high-voltage direct-current circuit L. The target vehicle 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 a motor and other components for directly outputting vehicle driving power. The non-power system load component F2 includes an instrument, a sensor, a controller (including a VCU, etc.), an air conditioner, a car machine, and other components that do not output vehicle driving power. The total controller M1 controls the target vehicle load component F to be electrically connected with the high-voltage direct-current circuit L through the corresponding load high-voltage switch component KF.

[0069] In the implementation process, the switch component (including the total charging switch component KS, the battery cluster high-voltage switch component KB, and the load high-voltage switch component KF) can be implemented by using a junction field effect transistor (JFET), a metal-oxide semiconductor field effect transistor (MOSFET), an insulate-gate bipolar transistor (IGBT), a relay, a contactor, etc. For the power system load component F1, since it is prone to arc discharge and other electrical shocks when electrically connected with the high-voltage direct-current circuit L, the load high-voltage switch component KF corresponding to the power system load component F1 can further include a pre-charge circuit. The embodiment of the present application does not make too many limitations here.

[0070] The vehicle multi-cluster power battery system control method provided by the embodiment of the present application will be described below.

[0071] As shown in Figure 2 , the method specifically includes the following steps:

[0072] S100, performing an initialization operation.

[0073] Optionally, the initialization operation can include: the total controller, in response to a vehicle start instruction (for example, an ON instruction), wakes up by receiving the power provided by the auxiliary power supply through the auxiliary power supply line. After the total controller is powered on and wakes up, the total controller controls the closure of the auxiliary power supply switch part corresponding to each main controller, so as to realize that each auxiliary power supply line provides power for the main controller, and then the total controller sends a wake-up signal to each main controller to realize the wake-up of each main controller. Then, the main controller sends a wake-up signal to each slave controller of the corresponding battery cluster after waking up, so as to wake up each slave controller. Wherein, the main controller and the slave controller can access the auxiliary power supply line through the auxiliary power supply switch part corresponding to each of them, the total controller sends a wake-up signal to the main controller to wake up the main controller by controlling the closure of the auxiliary power supply switch part corresponding to the main controller, and the main controller sends a wake-up signal to the slave controller to wake up the slave controller by closing the auxiliary power supply switch part corresponding to the slave controller. After the main controller and the slave controller are both woken up, fault self-checking is performed. Wherein, the fault self-checking specifically includes at least one of the following: checking whether the high-voltage interlocking mechanism is normal, checking whether the auxiliary power supply is normal (for example, whether the output voltage of the auxiliary power supply is normal), checking whether each battery cluster is normal through the main controller and the slave controller (for example, whether the current voltage of the battery cluster is normal, whether the temperature of the battery cluster is normal, etc.). During the fault self-checking, the total controller can periodically report to the VCU that the BMS is in the initialization self-checking state message, and after the fault self-checking is passed, the total controller reports to the VCU that the BMS self-checking is completed State message; if the fault self-checking fails, the total controller reports the fault state message to the VCU, and carries specific fault type (for example, fault code), fault level and other information in the fault message.

[0074] S101, determine to enter the discharge mode.

[0075] When the initialization operation is completed and the fault self-checking is passed, it is determined to enter the discharge mode.

[0076] S102, obtain the corresponding first voltage from the main controller corresponding to each battery cluster currently in the dischargeable state.

[0077] Wherein, the first voltage is the total voltage of the corresponding battery cluster which is not connected to the high-voltage direct current circuit.

[0078] S103, judge the size relationship between the first difference value between the highest first voltage and the lowest first voltage in the current first voltage and the target threshold value.

[0079] If the first difference value is less than or equal to the target threshold value, step S201 is executed.

[0080] S201. Send the clustering instruction to the corresponding master controller in the order of the first voltage from low to high, so that each master controller connects the corresponding first battery cluster to the high-voltage direct current circuit in response to the clustering instruction.

[0081] For ease of understanding, in the embodiments of the present application, the battery cluster connected to the high-voltage direct current circuit is referred to as the first battery cluster.

[0082] In the specific implementation process, the master controller controls the battery cluster high-voltage switch component of the corresponding first battery cluster to be closed, so as to realize the electrical connection between the first battery cluster and the high-voltage direct current circuit.

[0083] S202. Determine whether all first battery clusters have been connected to the high-voltage direct current circuit, and then send the load high-voltage power-on instruction to the VCU.

[0084] S203. Receive the load high-voltage power-on instruction sent by the VCU in response to the load high-voltage power-on instruction, and control the target vehicle-mounted load component indicated by the load high-voltage power-on instruction to be connected to the high-voltage direct current circuit, so that the first battery cluster supplies power to the target vehicle-mounted load component through the high-voltage direct current circuit.

[0085] In the specific implementation process, the load high-voltage power-on instruction can be used to instruct the total controller to connect a single target vehicle-mounted load component to the high-voltage direct current circuit, or can be used to instruct the total controller to connect a component group composed of multiple target vehicle-mounted load components to the high-voltage direct current circuit, which is not limited in the embodiments of the present application.

[0086] Through the above steps, by detecting the first voltage of all battery clusters in a dischargeable state when controlling the multi-cluster battery system to discharge the target vehicle-mounted load component, and only controlling all battery clusters to discharge the target vehicle-mounted load component when the difference between each first voltage is not large, the problems of circulating current, electrical shock and the like caused by the large difference between the voltages of each battery cluster can be avoided, and the safety, reliability and battery life of the multi-cluster power battery system are ensured.

[0087] Optionally, in step S102, if the first difference is greater than the target threshold, steps S300 and / or S301 are performed.

[0088] S300. Send alarm information indicating that the state of the battery cluster is abnormal to the user, so as to remind the user to check whether the vehicle has failed and to provide fault maintenance suggestions, for example, suggesting the user to try to repair by charging the battery cluster.

[0089] S301. Determine whether the forced discharge condition is met.

[0090] If the forced discharge condition is met, step S302 is performed.

[0091] In a specific implementation, the forced discharge condition can be receiving a forced discharge mode message. The forced discharge mode message can be triggered automatically by a vehicle controller such as a VCU according to driving control logic (e.g., automatic driving logic), or can be triggered based on user operation. Further, the forced discharge mode message can be generated based on user operation and sent directly to the master controller, or the forced discharge instruction can be triggered based on user operation and sent to the VCU, and the VCU generates the forced discharge mode message based on the forced discharge instruction triggered by the user and sends it to the master controller. The way the user triggers the forced discharge mode message / forced discharge instruction can be set according to actual needs, for example, when the first difference is greater than the target threshold, the vehicle displays a prompt on the instrument screen to ask the user whether to start the forced discharge mode, and the user triggers the confirmation operation on the instrument screen to generate the forced discharge mode message / generate the forced discharge instruction and send it to the VCU; for example, when the first difference is greater than the target threshold, the vehicle displays a prompt on the instrument screen to ask the user whether to start the forced discharge mode, and generates the forced discharge mode message / generates the forced discharge instruction based on the user's operation on the vehicle driving control component (e.g., stepping on the accelerator pedal, etc.) and sends it to the VCU. The present embodiment does not make too many limitations here.

[0092] S302, determining to enter the forced discharge mode.

[0093] S303, sending a power-on instruction to the master controller corresponding to the highest first voltage, so that the master controller corresponding to the highest first voltage controls the first battery cluster corresponding to the highest first voltage to access the high-voltage direct current circuit in response to the power-on instruction.

[0094] S304, determining that the first battery cluster corresponding to the highest first voltage has accessed the high-voltage direct current circuit, and sending a high-voltage load permission instruction to the VCU.

[0095] S305, receiving a load high-voltage power-on instruction sent by the VCU in response to the high-voltage load permission instruction, and controlling the target vehicle load component indicated by the load high-voltage power-on instruction to access the high-voltage direct current circuit, so that the first battery cluster supplies power to the target vehicle load component through the high-voltage direct current circuit.

[0096] Since the specific implementation of steps S304 and S305 is basically the same as the specific implementation of steps S202 and S203 described above, the corresponding implementation can be referred to the foregoing content, and will not be repeated here.

[0097] In this way, when the first voltage of each battery cluster in the power battery system of the vehicle is too different and the vehicle cannot be powered by the parallel cluster power supply, only the first battery cluster corresponding to the highest first voltage can be controlled to forcibly power the vehicle, so that the vehicle can still be powered when the battery cluster of the power battery is abnormal, and in particular, the power system load components of the vehicle can be powered to provide power for the vehicle, so that the vehicle can move (for example, if the first battery cluster corresponding to the highest first voltage is sufficient to provide the power required for normal driving of the vehicle, the vehicle can be powered in a normal driving state; for example, if the first battery cluster corresponding to the highest first voltage is insufficient to provide the power required for normal driving of the vehicle, the first battery cluster corresponding to the highest first voltage can provide energy for the power system load components to enable the vehicle to creep, facilitating emergency handling of the vehicle to move to a parking position, and improving the emergency capability of the vehicle).

[0098] In the process of powering the vehicle by the first battery cluster in parallel cluster described in steps S201-S203, and in the process of powering the vehicle by the first battery cluster corresponding to the highest first voltage described in steps S301-S305, when the battery cluster needs to end the power supply to the vehicle, because the voltage and current of the circuit loop formed between the high-voltage direct-current circuit and the electrically connected first battery cluster and the target vehicle load component are relatively high, directly performing the electrically connected disconnection action is easy to cause electric arc discharge and other electrical shocks. In order to ensure safety, the power supply can be ended in the following way:

[0099] S401, determine whether the discharge end condition is met.

[0100] If the discharge end condition is met, step S402 is performed; if the discharge end condition is not met, the step of maintaining the first battery cluster supplying power to the target vehicle load component through the high-voltage direct-current circuit is maintained.

[0101] In a specific implementation process, the discharge end condition can include: receiving a discharge end instruction sent by the VCU, or the power supply time of the first battery cluster supplying power to the target vehicle load component through the high-voltage direct-current circuit reaching a preset discharge time length, or determining that the current voltage of the first battery cluster reaches a voltage lower limit value; or determining that the current power of the first battery cluster reaches a power lower limit value. Furthermore, for the forced discharge mode, if the user inserts the charging plug of the charger into the charging socket of the vehicle without exiting the forced discharge mode, at this time the vehicle can have a conflict behavior that the first battery cluster discharges to the target vehicle load component and the charger charges the first battery cluster. Then the discharge end condition can also include: currently being in the forced discharge mode, and the total controller detecting a charging connection confirmation signal generated by the charger.

[0102] The VCU can determine that the first battery cluster needs to end power supply according to the operation instruction of the user or the automatic driving control logic, and send a discharge end instruction to the general controller; or the VCU determines that there is a first battery cluster with a preset fault level and / or a preset fault category in the first battery cluster connected to the high-voltage direct current circuit according to the state information of the first battery cluster reported by the general controller, and sends a discharge end instruction to the general controller. Further, for the forced discharge mode, if the user inserts the charger into the charging socket of the vehicle without exiting the forced discharge mode, the general controller can report an exit discharge end request to the VCU when it is in the forced discharge mode and detects the charging connection confirmation signal generated by the charger, and the VCU sends a discharge end instruction to the general controller according to the discharge end request. The present embodiment does not make too many limitations here.

[0103] S402, send a current adjustment instruction to the main controller corresponding to each first battery cluster. So that each main controller responds to the current adjustment instruction to control the corresponding first battery cluster to adjust the discharge current output to the high-voltage direct current circuit to the rated discharge minimum value.

[0104] In the specific implementation process, the rated discharge minimum value can be 0, or a small current value other than 0.

[0105] S403, when the power-down condition is met, control each target vehicle-mounted load component to be disconnected from the high-voltage direct current circuit.

[0106] The power-down condition includes that the current value received by the high-voltage direct current circuit is less than a preset current threshold, or the time length from the current moment to the moment when the current adjustment instruction is sent is greater than a preset power-down time length.

[0107] Preferably, the preset current threshold can be set to a current value of 15A or less.

[0108] S404, after each target vehicle-mounted load component is disconnected from the high-voltage direct current circuit, send a battery cluster power-down instruction to each main controller. So that each main controller responds to the battery cluster power-down instruction to disconnect the corresponding first battery cluster from the high-voltage direct current circuit.

[0109] In this way, the safety risk caused by directly performing circuit on-off operation on the high-voltage direct current circuit in a large current state can be avoided.

[0110] Optionally, after determining that each first battery cluster is disconnected from the high-voltage direct current circuit, the general controller can report state information of each target vehicle-mounted load component and / or first battery cluster completing disconnection from the high-voltage direct current circuit to the VCU.

[0111] Optionally, in the process of supplying power to the target vehicle load components through the high-voltage direct current circuit in the first battery cluster mode through the above steps S201-S203, if the user connects the charging plug of the charger to the charging socket of the vehicle at this time, the vehicle needs to be switched from the discharging mode to the charging mode to charge the battery cluster. The embodiment of the present application provides a method, without the operation of lowering and re-raising the high-voltage direct current circuit by the first battery cluster and the non-power system load components, the charging state can be switched to charge the first battery cluster, and the continuous operation of the non-power system load components is maintained. Specifically, the following steps are included:

[0112] S501, determine whether a charging connection confirmation signal generated by the charger is detected.

[0113] If the charging connection confirmation signal is detected, step S502 is performed; if the charging connection confirmation signal is not detected, the step of supplying power to the target vehicle load components by the first battery cluster through the high-voltage direct current circuit is maintained.

[0114] In the specific implementation process, according to the Chinese national standard GB / T 20234, after the charger is connected to the charging port of the vehicle, the charger will apply a preset voltage signal to the CC2 signal line, and the total controller can monitor the voltage signal transmitted on the CC2 signal line: when the charger and the charging port of the vehicle are not completely connected or completely locked, the total controller will detect that the voltage signal transmitted on the CC2 signal line is an abnormal signal that does not meet the standard; when the charger and the charging port of the vehicle are completely connected and completely locked, the total controller will detect that the voltage signal transmitted on the CC2 signal line is a charging connection confirmation signal that meets the standard.

[0115] S502, send a stop discharging instruction to the main controller corresponding to each first battery cluster, so that each main controller controls the corresponding first battery cluster to stop discharging to the high-voltage direct current circuit in response to the stop discharging instruction.

[0116] S503, send a charging state message to the VCU for indicating that the charging connection confirmation signal is detected.

[0117] S504, receive the power system load component power-off instruction sent by the VCU in response to the charging state message, and control the power system load component to disconnect from the high-voltage direct current circuit.

[0118] S505, determine that the power system load component is disconnected from the high-voltage direct current circuit, and determine to enter the charging mode.

[0119] S506, through signaling interaction with the charger, charge the first battery cluster through the high-voltage direct current circuit, and supply power to the non-power system load components through the high-voltage direct current circuit.

[0120] Thus, by detecting the connection of the charger to the charging socket of the vehicle during the process of supplying power to the target vehicle load components through the high-voltage direct current circuit by the first battery cluster, only the electrical connection between the power system load components and the high-voltage direct current circuit is disconnected, while the electrical connection between the first battery cluster and the non-power system load components and the high-voltage direct current circuit is still maintained, so that the power-on and power-off operations of the switching components of the first battery cluster, the non-power system load components and the high-voltage direct current circuit can be reduced, and the efficiency of switching the vehicle from the discharging mode to the charging mode can be improved.

[0121] Specifically, the general controller realizes the specific implementation of charging the first battery cluster through the high-voltage direct current circuit and supplying power to the non-power system load components through the high-voltage direct current circuit by signaling interaction with the charger, as shown in the specific implementation of Figure 3 includes the following steps:

[0122] S601, closing the general charging switching component corresponding to the high-voltage direct current circuit.

[0123] S602, sending a charging preparation ready message to the charger. The first battery cluster is charged by receiving the power supply current output by the charger in response to the charging preparation ready message through the high-voltage direct current circuit.

[0124] In the specific implementation process, according to the Chinese national standard GB / T 27930, the charging preparation ready message can be a BRO=0xAA message to inform the charger to start outputting current for charging.

[0125] In the specific implementation process, after determining to enter the charging mode, the general controller 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). If the charging preparation ready message is not sent within a specified time period from the first time the charging preparation not ready message is sent, the charging process is terminated.

[0126] Further, during the process of connecting each first battery cluster to the high-voltage direct current circuit for charging, when any first battery cluster reaches the full charging condition and needs to end charging, since the current target current of the high-voltage direct current circuit is large when the first battery cluster is connected for charging, directly disconnecting the electrical connection between the first battery cluster (hereinafter referred to as the second battery cluster) that needs to end charging and the high-voltage direct current circuit has a safety risk, therefore, the following steps can be used to realize the de-clustering operation of the second battery cluster to disconnect the second battery cluster from the high-voltage direct current circuit:

[0127] S604, determining whether there is a second battery cluster that reaches the full charging condition in the current first battery cluster.

[0128] If the second battery cluster exists in the first battery cluster, step S605 is performed; if the second battery cluster does not exist in the first battery cluster, the step of charging the first battery cluster through the high-voltage direct current circuit and the step of supplying power to the non-power system load components through the high-voltage direct current circuit are maintained.

[0129] Optionally, the full-charge condition includes that the current voltage of the battery cluster reaches the preset full-charge voltage corresponding to the battery cluster, or the current capacity of the battery cluster reaches the preset full-charge capacity corresponding to the battery cluster, or a full-charge instruction indicating that the battery cluster reaches the full-charge state is received. For example, for any first battery cluster, if it is determined that the current voltage of the first battery cluster reaches the preset full-charge voltage corresponding to the first battery cluster, the first battery cluster is determined to be the second battery cluster. For another example, the charger generates a full-charge instruction indicating that a specified first battery cluster reaches the full-charge state in response to the operation of a user (for example, a manual card swiping operation) and sends the full-charge instruction to the BMS, and the total controller determines that the specified first battery cluster is the second battery cluster after receiving the full-charge instruction.

[0130] S605, sending a current adjustment instruction to the charger to request the charger to adjust the current value of the power supply current output by the high-voltage direct current circuit to the rated minimum current value of the charger.

[0131] Preferably, the rated minimum current value of the charger can be set to 5A.

[0132] S606, when the power-down condition is satisfied, sending a cluster withdrawal instruction to the main controller corresponding to the second battery cluster to make the main controller disconnect the second battery cluster from the high-voltage direct current circuit in response to the cluster withdrawal instruction.

[0133] The power-down condition includes that the current value received by the high-voltage direct current circuit is less than a preset current threshold, or the time length from the current time to the time when the current adjustment instruction is sent is greater than a preset power-down time length.

[0134] Preferably, the preset current threshold can be set to a current value of 15A or less, so as to avoid the safety risk caused by the circuit on-off operation of the high-voltage direct current circuit in the large current state.

[0135] During the charging of the first battery cluster by the high-voltage direct current circuit, the power supply current needs to be configured in a safe manner. Accordingly, whenever the number of the first battery cluster being charged changes (for example, when the charger starts to charge the first battery cluster through the high-voltage direct current circuit, and when the second battery cluster completes the cluster withdrawal), the following step S603 is further included:

[0136] S603, whenever the number of the first battery clusters being charged changes, determining a target current according to the minimum value in the allowed charging currents of the current first battery clusters, the current number of the first battery clusters, the rated capacity of the multi-cluster power battery system, the current attenuation coefficient, and the upper limit value of the power supply current corresponding to the charger, and sending a charging parameter request message for indicating the target current to the charger, so that the charger supplies power to the charging circuit at the target voltage and the target current in response to the charging parameter request message.

[0137] The target voltage is a battery cluster rated voltage. In the specific implementation process, the specific value of the battery cluster rated voltage can be set according to the specifications of the battery cluster. For example, the battery cluster is composed of 12 single batteries in parallel through 4 parallel branches, and each parallel branch includes 3 single batteries in series. Then, the battery cluster rated voltage can be determined as 3 times the rated voltage of the single battery.

[0138] In the specific implementation process, the current attenuation coefficient α may be a preset fixed value, or a variable value determined according to the current situation.

[0139] Further, the current attenuation coefficient is related to at least one of the number of the first battery clusters, the battery formula, and the heat dissipation performance of the battery system.

[0140] Further, the upper limit value of the power supply current corresponding to the charger is related to the number of the chargers and the charging mode performed by the chargers.

[0141] For example, when the charger performs charging in the charging mode of the national standard, regardless of the number of the chargers connected to the high-voltage direct-current circuit of the vehicle, the total upper limit value of the power supply current corresponding to all the chargers is always a preset fixed value (for example, 400A). If there are multiple chargers, the sum of the target currents corresponding to each charger does not exceed the total upper limit value of the power supply current corresponding to all the chargers (for example, the total upper limit value of the power supply current corresponding to all the chargers is 400A, and if the number of the chargers connected to the high-voltage direct-current circuit of the vehicle is 4, the upper limit value of the power supply current corresponding to a single charger = 100A). When the charger performs charging in a specific charging mode of a non-national standard (for example, a group standard), the upper limit value of the power supply current corresponding to a single charger can be a preset fixed value (for example, 400A), and the total upper limit value of the power supply current corresponding to all the chargers can be the sum of the upper limit values of the power supply current corresponding to each charger (for example, the upper limit value of the power supply current corresponding to a single charger , if the number of the charger accessing the high-voltage direct-current circuit of the vehicle is 4, and the total upper limit of the rated supply current corresponding to all the chargers is 1600A.

[0142] In an optional embodiment, the target current may be determined in the following manner:

[0143]

[0144] wherein, α is a current attenuation coefficient, is the number of the current first battery cluster, is the minimum allowable charging current among the allowable charging currents of the current first battery clusters, is a preset coefficient, Q is the rated capacity of the multi-cluster power battery system (i.e., the total charge amount corresponding to all the battery clusters, which can be measured in coulombs C or ampere-hours A·h), is the upper limit of the rated supply current corresponding to the charger. Preferably, .

[0145] In an optional embodiment, the current attenuation coefficient α is determined in the following manner:

[0146]

[0147]

[0148] wherein, , is a preset coefficient. F is a battery formula parameter, which can be set according to the formula of the power battery, for example, the battery formula parameters of the lithium iron phosphate battery and the ternary lithium battery are F different. H is a heat dissipation performance parameter of the battery system, which can be determined by calibration according to the actual heat dissipation performance of the battery system. is the number of the current first battery cluster. By setting the current attenuation coefficient α when the number of the current first battery cluster is greater than 1 to be smaller than the current attenuation coefficient α when the number of the current first battery cluster is equal to 1, the circulating current phenomenon generated in the high-voltage direct-current circuit due to the voltage imbalance of different first battery clusters is suppressed, and the heat effect generated in the high-voltage direct-current circuit when charging the battery cluster at a large current is reduced. Preferably, , .

[0149] In this way, the target current of the high-voltage direct current circuit determined by the above method for charging the first battery cluster can protect the first battery cluster with the minimum allowed charging current, dynamically limit the power supply current by adjusting the attenuation coefficient, realize flexible control of the power supply current, avoid overcharging of the first battery cluster, and avoid the power supply current exceeding the rated upper limit of the charger.

[0150] Further, when the charging is completed, in order to ensure safety, the electrical connection between the charger and the high-voltage direct current circuit, and the charging circuit and the target vehicle-mounted load component can also be disconnected by a similar step as the cluster withdrawal operation:

[0151] If the second battery cluster does not exist in the first battery cluster, step S607 is performed.

[0152] S607, determine whether the charging end condition is met.

[0153] If the charging end condition is met, step S608 is performed; if the charging end condition is not met, return to step S603 and maintain the steps of charging the first battery cluster through the high-voltage direct current circuit and supplying power to the non-power system load component through the high-voltage direct current circuit.

[0154] Alternatively, the charging end condition includes: determining that there is no first battery cluster being connected to the high-voltage direct current circuit for charging whenever the number of the first battery cluster changes; or receiving a charging end instruction; or determining that the first battery cluster has a fault of a preset fault category and / or a preset fault level.

[0155] For example, the charger generates a charging end instruction in response to the user's operation (such as manual card swiping operation using a magnetic card) and sends it to the BMS. After receiving the charging end instruction, the total controller determines that the charging end condition is met.

[0156] Further, if the charging end condition is triggered by determining that the first battery cluster has a fault of a preset fault category and / or a preset fault level, the total controller can also report the fault category and / or the fault level to the VCU.

[0157] S608, send a current adjustment instruction to the charger to request the charger to adjust the current value of the power supply current output to the high-voltage direct current circuit to the rated minimum current value of the charger.

[0158] S609, when it is determined that the power-down condition is met, disconnect the total charging switch component. After determining that the total charging switch component is disconnected, it is determined to exit the charging mode and control the components connected to the high-voltage direct current circuit to disconnect the connection with the high-voltage direct current circuit, respectively.

[0159] The components that have accessed the HVDC circuit include at least non-power system load components. In addition, if the first battery cluster is accessing the HVDC circuit for charging and the first battery cluster is not completing the charging process, the components that have accessed the HVDC circuit further include the first battery cluster that is accessing the HVDC circuit, according to the received charging end instruction to determine that the charging end condition is met to disconnect the electrical connection of the total charging switch component.

[0160] The power-off condition includes that the current value received by the HVDC circuit is less than a preset current threshold, or the time length from the current time to the time when the current adjustment instruction is sent is greater than a preset power-off time length.

[0161] In the specific implementation process, if the HVDC circuit further includes a switch component (such as a bus cabinet) that can control the on-off of an electrical circuit, after determining to exit the charging mode, the total controller can further control the switch component in the HVDC circuit to disconnect.

[0162] In the specific implementation process, in order to facilitate the VCU to manage the state of the vehicle battery, when the total controller determines that the power-off condition is met, the total controller can first report an exit charging mode request instruction to the VCU, the VCU sends an allow exit charging mode instruction to the total controller in response to the exit charging mode request instruction, and the total controller disconnects the total charging switch component after receiving the allow exit charging mode instruction.

[0163] In the specific implementation process, after the total controller performs the operation of disconnecting the total charging switch component, the total controller can determine that the total charging switch component is disconnected after collecting sensing information confirming that the total charging switch component is disconnected; or the total controller determines that the total charging switch component is disconnected after a preset first timeout period (for example, 5s) of performing the operation of disconnecting the total charging switch component. Similarly, after the total controller controls the components that have accessed the HVDC circuit to disconnect the connection with the HVDC circuit, the total controller determines that the corresponding components are disconnected after collecting sensing information confirming that the corresponding components are disconnected; or the total controller determines that the corresponding components are disconnected after a preset second timeout period (for example, 5s) of performing the operation of disconnecting the corresponding components.

[0164] Further, after all the above steps are completed, the total controller can further stop sending the wake-up signal to the main controller after the wake-up source provided through the auxiliary power line disappears, so that the main controller stops sending the wake-up signal to the slave controller. Finally, the total controller saves the monitoring data in the current charging process and enters sleep.

[0165] In the above method, for the target threshold value used in the step S103, the target threshold value is used to determine that the vehicle currently targets the battery cluster for discharging mode or forced discharging mode to supply power to the vehicle-mounted load components. The target threshold value can be a preset fixed value (for example, 5V) set according to actual needs; or the target threshold value can be set as a dynamically adjusted variable value considering that the state of the battery cluster will be different as the use time is long, and the safety of the battery cluster clustering process is guaranteed under different impedance, temperature and battery aging degree. If the target threshold value is a dynamically adjusted variable value, the target threshold value can be determined in the following manner:

[0166] If the target threshold value is acquired for the first time, the target threshold value is a preset initial value.

[0167] If the target threshold value is not acquired for the first time, the target threshold value is determined in the following manner:

[0168] When the first difference between the highest first voltage and the lowest first voltage determined last time is less than or equal to the target threshold value, the instantaneous maximum current value generated between the battery cluster and the high-voltage direct current circuit when the battery cluster is connected to the high-voltage direct current circuit is collected; if it is determined that there is no instantaneous maximum current value greater than the preset instantaneous current threshold value, the target threshold value is kept unchanged; if it is determined that there is an instantaneous maximum current value greater than the preset instantaneous current threshold value, the value of the target threshold value is adjusted as an updated target threshold value.

[0169] Optionally, each time the value of the target threshold value is adjusted, the value of the target threshold value can be increased by a preset step to obtain a to-be-determined target threshold value, and when the to-be-determined target threshold value is not greater than the upper limit of the target threshold value, the to-be-determined target threshold value is taken as the updated target threshold value, and when the to-be-determined target threshold value is greater than the upper limit of the target threshold value, the upper limit of the target threshold value is taken as the updated target threshold value. Alternatively, each time the value of the target threshold value is adjusted, the value of the target threshold value can be decreased by a preset step to obtain a to-be-determined target threshold value, and when the to-be-determined target threshold value is not less than the lower limit of the target threshold value, the to-be-determined target threshold value is taken as the updated target threshold value, and when the to-be-determined target threshold value is less than the lower limit of the target threshold value, the lower limit of the target threshold value is taken as the updated target threshold value.

[0170] In the specific implementation process, the target threshold value can be stored in the non-volatile memory of the total controller and maintained and updated in the form of a variable. For example, the target threshold value can be stored in the Electrically Erasable Programmable Read Only Memory (EEPROM) of the total controller and updated and maintained in the form of a variable.

[0171] In the implementation process, when the first difference between the highest first voltage and the lowest first voltage in the last determination is less than or equal to the target threshold, the process of the battery cluster accessing the high-voltage direct current circuit includes the process of the battery cluster and the target vehicle-mounted load component (including the non-power system load component and the power system load component) accessing the high-voltage direct current circuit when the vehicle is not electrically connected with the charger (i.e., the first battery cluster corresponding to the first voltage is in the dischargeable state when the first battery cluster is in the discharging mode), and can also include the process of the battery cluster accessing the high-voltage direct current circuit for charging when the vehicle is electrically connected with the charger (i.e., the first battery cluster corresponding to the first voltage is in the chargeable state when the first battery cluster is in the charging mode). Optionally, as shown in Figure 4 The process of the battery cluster accessing the high-voltage direct current circuit for charging can include the following steps:

[0172] S700, performing an initialization operation.

[0173] Optionally, the initialization operation can include: waking up by the electric energy provided by the charger received through the auxiliary power line (for example, the auxiliary power positive power line of the auxiliary power line); and sending a wake-up signal to the main controller to wake up the main controller. So that the main controller wakes up each slave controller of the corresponding battery cluster after waking up.

[0174] S701, after detecting the charging connection confirmation signal generated by the charger, determining to enter the charging mode.

[0175] S702, obtaining the corresponding first voltage from the main controller of each battery cluster currently in the chargeable state.

[0176] S703, determining the size relationship between the first difference between the highest first voltage and the lowest first voltage in the current first voltage and the target threshold.

[0177] If the first difference is greater than the target threshold, step S704 is performed.

[0178] S704, sending a cluster instruction to the main controller corresponding to the lowest first voltage, so that the main controller accesses the high-voltage direct current circuit with the battery cluster corresponding to the lowest first voltage as the first battery cluster in response to the cluster instruction.

[0179] For example, there are currently four battery clusters B1, B2, B3 and B4, and the corresponding first voltages are: battery cluster B1: 5.52V, battery cluster B2: 6.75V, battery cluster B3: 8.86V, and battery cluster B4: 11.35V. Then the first difference is If the target threshold value is 5V, the total controller M1 sends a cluster instruction to the main controller M2-1 corresponding to the battery cluster B1, and the main controller M2-1 accesses the battery cluster B1 as the first battery cluster into the high-voltage direct current circuit.

[0180] S705, after determining that the first battery cluster has accessed the high-voltage direct current circuit, closing the total charging switch component corresponding to the high-voltage direct current circuit, and sending a charging preparation ready message to the charger. In order to charge the first battery cluster by receiving the charging current output by the charger in response to the charging preparation ready message through the high-voltage direct current circuit.

[0181] S706, judging whether there is a first charging cluster currently being charged.

[0182] If there is a first charging cluster currently being charged, step S707 is executed. If there is no first charging cluster currently being charged, step S713 is executed.

[0183] S707, collecting a second voltage. The second voltage is the total voltage of the overall circuit structure composed of each first battery cluster.

[0184] In the specific implementation process, the total controller can measure the voltage at the busbar side of the busbar cabinet and the like structure of the high-voltage direct current circuit as the second voltage.

[0185] S708, judging whether the current second voltage and the lowest first voltage among the current first voltages satisfy the cluster condition.

[0186] If the cluster condition is satisfied, step S709 is executed; if the cluster condition is not satisfied, step S713 is executed.

[0187] Optionally, the cluster condition includes:

[0188] (1) the second difference between the current second voltage and the current lowest first voltage is less than a preset second threshold value.

[0189] (2) within a preset time length, 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 value and less than a preset third threshold value.

[0190] Preferably, the preset second threshold value can be set to 3V; the preset third threshold value can be set to 6V, and the preset time length can be set to 500ms.

[0191] Further optionally, if the second difference between the current second voltage and the current lowest first voltage is greater than the preset third threshold value, an alarm information indicating that the charging state is abnormal can be sent. In order to remind the user to check whether the vehicle has failed.

[0192] S709. Send a clustering instruction to the master controller corresponding to the current lowest first voltage, so that the master controller accesses the battery cluster corresponding to the current lowest first voltage as a new first battery cluster into the high-voltage direct current circuit for charging in response to the clustering instruction.

[0193] For example, there are currently 2 battery clusters B3 and B4 to be charged and 2 first battery clusters B1 and B2, wherein the first voltage corresponding to the battery clusters to be charged is: battery cluster B3: 8.86V, battery cluster B4: 11.35V; the second voltage corresponding to the first battery clusters B1 and B2 as a whole is 9.1V. At this time, the second difference is , if the preset second threshold value is 3V, then the clustering condition is met at this time, and the total controller will send a clustering instruction to the master controller M2-3 corresponding to the battery cluster B3, and the master controller M2-3 will access the battery cluster B3 as a first battery cluster into the high-voltage direct current circuit.

[0194] Correspondingly, whenever the number of the first battery clusters changes, the following steps are further included:

[0195] According to the minimum value of the allowed charging current of the current first battery clusters, the current number of the first battery clusters, the rated capacity of the multi-cluster power battery system, the current attenuation coefficient, and the charging current rated upper limit value corresponding to the charger, a target current is determined, and a charging parameter request message for indicating the target current is sent to the charger. So that the charger supplies power to the high-voltage direct current circuit at the target voltage and the target current in response to the charging parameter request message.

[0196] This part of the specific content is consistent with the corresponding content in the previous text, and can refer to the corresponding implementation of the previous text. Here, it will not be repeated.

[0197] S710. Determine whether there is a second battery cluster reaching the full charging condition in the current first battery clusters.

[0198] If there is a second battery cluster in the first battery clusters, step S711 is performed; if there is no second battery cluster in the first battery clusters, step S713 is performed.

[0199] Optionally, the full charging condition includes: the current voltage of the battery cluster reaches the preset full charging voltage corresponding to the battery cluster; or the current capacity of the battery cluster reaches the preset full charging capacity corresponding to the battery cluster; or a full charging instruction indicating that the battery cluster reaches the full charging state is received.

[0200] S711. Send a current adjustment instruction to the charger for requesting the charger to adjust the current value of the charging current output to the high-voltage direct current circuit to the rated minimum current value of the charger.

[0201] S712, when it is determined that the power-off condition is met, sending a cluster-out instruction to the main controller corresponding to the second battery cluster, so that the main controller disconnects the second battery cluster from the high-voltage direct current circuit in response to the cluster-out instruction.

[0202] The power-off condition includes that a current value of the charging current received by the high-voltage direct current circuit is less than a preset current threshold, or a time length from a time point when the current adjustment instruction is sent to a current time point is greater than a preset power-off time length.

[0203] S713, determining whether a charging end condition is met.

[0204] If the charging end condition is met, step S714 is performed; if the charging end condition is not met, step S706 is returned.

[0205] Optionally, the charging end condition includes that, after the second battery cluster is disconnected from the high-voltage direct current circuit, it is determined that there is no first battery cluster that is currently accessing the high-voltage direct current circuit for charging; or, a charging end instruction is received; or, it is determined that the second battery cluster has a fault of a preset fault category and / or a preset fault level.

[0206] Further, if it is determined that the first battery cluster has a fault of a preset fault category and / or a preset fault level, the total controller can further report the fault category and / or the fault level to the VCU.

[0207] S714, sending a current adjustment instruction to the charger, to request the charger to adjust a current value of the charging current output to the high-voltage direct current circuit to a minimum rated current value of the charger.

[0208] S715, when it is determined that the power-off condition is met, disconnecting the total charging switch component. After the total charging switch component is disconnected, it is determined to exit the charging mode, and the components that have accessed the high-voltage direct current circuit are controlled to disconnect from the high-voltage direct current circuit.

[0209] The power-off condition includes that a current value of the charging current received by the high-voltage direct current circuit is less than a preset current threshold, or a time length from a time point when the current adjustment instruction is sent to a current time point is greater than a preset power-off time length.

[0210] The components that have accessed the high-voltage direct current circuit at least include non-power system load components. In addition, if the first battery cluster is currently accessing the high-voltage direct current circuit for charging, and the charging end condition is determined to be met according to the received charging end instruction, so as to disconnect the high-voltage direct current circuit from the total charging switch component, the components that have accessed the high-voltage direct current circuit further include the first battery cluster that is currently accessing the high-voltage direct current circuit.

[0211] 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.

[0212] 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.

[0213] 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.

[0214] 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.

[0215] Optionally, such as Figure 5 As shown, in step S703, if it is determined that the first difference is less than or equal to the target threshold, the following steps can be performed:

[0216] S804. 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 battery cluster as the first battery cluster to the high voltage DC circuit.

[0217] For example, there are currently four battery clusters B1, B2, B3, and B4 waiting to be charged, with the following first voltages: B1: 5.52V, B2: 6.75V, B3: 8.86V, and B4: 9.12V. Then, the first difference... If the target threshold is 5V, the total controller M1 sends a clustering instruction to the master controller M2-1 corresponding to the battery cluster B1, the master controller M2-1 connects the first battery cluster B1 to the high-voltage direct current circuit; then the total controller M1 sends a clustering instruction to the master controller M2-2 corresponding to the battery cluster B2, the master controller M2-2 connects the first battery cluster B2 to the high-voltage direct current circuit; then the total controller M1 sends a clustering instruction to the master controller M2-3 corresponding to the battery cluster B3, the master controller M2-3 connects the first battery cluster B3 to the high-voltage direct current circuit; then the total controller M1 sends a clustering instruction to the master controller M2-4 corresponding to the battery cluster B4, the master controller M2-4 connects the first battery cluster B4 to the high-voltage direct current circuit.

[0218] S805, after determining that all the first battery clusters have been connected to the high-voltage direct current circuit, closing the total charging switch component corresponding to the high-voltage direct current circuit and sending a charging preparation ready message to the charger. The second battery clusters are charged by receiving the charging current output by the charger in response to the charging preparation ready message through the high-voltage direct current circuit.

[0219] S806, determining whether there is a first charging cluster currently being charged.

[0220] If there is a first charging cluster currently being charged, step S207 is executed; if there is no first charging cluster currently being charged, step S813 is executed.

[0221] S807, collecting a second voltage. The second voltage is the total voltage of the overall circuit structure formed by the first battery clusters.

[0222] S810, determining whether there is a second battery cluster reaching a full charging condition in the first battery clusters.

[0223] If there is a second battery cluster in the first battery clusters, step S211 is executed; if there is no second battery cluster in the first battery clusters, step S813 is executed.

[0224] Optionally, the full charging condition includes that the current voltage of the battery cluster reaches a preset full charging voltage corresponding to the battery cluster; or the current capacity of the battery cluster reaches a preset full charging capacity corresponding to the battery cluster; or a full charging instruction indicating that the battery cluster reaches a full charging state is received.

[0225] S811, sending a current adjustment instruction to the charger to request the charger to adjust the current value of the charging current output to the high-voltage direct current circuit to a rated minimum current value of the charger.

[0226] S812, when the power-down condition is met, sending a de-clustering instruction to the master controller corresponding to the second battery cluster to make the master controller disconnect the second battery cluster from the high-voltage direct current circuit in response to the de-clustering instruction.

[0227] The power-off condition comprises that a current value of a charging current received by the high-voltage direct-current circuit is less than a preset current threshold, or a time length from a current moment to a moment when the current adjustment instruction is sent is greater than a preset power-off time length.

[0228] S813, determine whether a charging end condition is met.

[0229] If the charging end condition is met, step S714 is executed; if the charging end condition is not met, step S806 is returned.

[0230] Optionally, the charging end condition comprises that, after the second battery cluster is disconnected from the high-voltage direct-current circuit, it is determined that there is no first battery cluster that is accessing the high-voltage direct-current circuit for charging; or, a charging end instruction is received; or, it is determined that the first battery cluster has a fault of a preset fault category and / or a preset fault level.

[0231] The vehicle multi-cluster power battery system control method and the battery management system provided by the embodiment of the application can avoid problems such as circulating current and electrical shock caused by too large voltage difference between each battery cluster, and ensure the safety, reliability and battery life of the multi-cluster power battery system.

[0232] Those skilled in the art should understand that embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage, etc.) containing computer-usable program code.

[0233] The present application is described with reference to flowcharts and / or block diagrams according to the methods, devices (systems), and computer program products of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to produce a machine, so that the instructions executed by the computer or other programmable data processing devices produce a device that implements the functions specified in the flowcharts and / or block diagrams. Figure 1 The device that implements the functions specified in one flow or multiple flows and / or blocks Figure 1 The device that implements the functions specified in one flow or multiple flows and / or blocks

[0234] These computer program instructions can also be stored in a computer- readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the Figure 1 function specified in the flow or flows and / or blocks Figure 1 of the block or blocks.

[0235] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions that are executed on the computer or other programmable apparatus provide steps for implementing the Figure 1 function specified in the flow or flows and / or blocks Figure 1 of the block or blocks.

[0236] Obviously, numerous modifications and variations of the present application are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims and their equivalents, the application can be practiced otherwise than as specifically described.

Claims

1. A control 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 the vehicle control unit (VCU) 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; Its features are, The method includes: After determining that the discharge 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 a clustering command is sent to the corresponding main controller in order of first voltage from low to high, so that the main controller responds to the clustering command and connects the corresponding first battery cluster to the high voltage DC circuit; wherein, for any first voltage, the first voltage is the total voltage of the corresponding battery cluster in the dischargeable state, and the first voltage is acquired by the main controller connected to the corresponding battery cluster; Once it is determined that all first 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. The system receives a load high-voltage power-on command sent by the VCU in response to the load high-voltage command, and controls the target vehicle load component indicated by the load high-voltage power-on command to connect to the high-voltage DC circuit; so that the first battery cluster supplies power to the target vehicle load component through the high-voltage DC circuit; wherein the target vehicle load component includes a power system load component and a non-power system load component; During the process of the first battery cluster supplying power to the target vehicle load component through the high-voltage DC circuit, if a charging connection confirmation signal generated by the charger is detected, a stop discharge command is sent to the main controller corresponding to each first battery cluster; so that each main controller responds to the stop discharge command and controls the corresponding first battery cluster to stop discharging to the high-voltage DC circuit. Send a charging status message to the VCU to indicate that the charging connection confirmation signal has been detected; Receive the power system load component power-down command sent by the VCU in response to the charging status message, and control the power system load component to disconnect from the high voltage DC circuit; After confirming that the load component of the power system is disconnected from the high-voltage DC circuit, the system enters the charging mode. By interacting with the charger via signaling, the first battery cluster is charged through the high-voltage DC circuit, and the non-power system load components are powered through the high-voltage DC circuit. During the charging process of the first battery cluster, whenever the number of the first battery clusters being charged changes, a target current is determined based on the minimum allowable charging current of each first battery cluster, the current number of the first battery clusters, the rated capacity of the multi-cluster power battery system, the current attenuation coefficient, and the rated upper limit of the power supply current corresponding to the charger. A charging parameter request message indicating the target current is sent to the charger so that the charger responds to the charging parameter request message and supplies power to the charging circuit with the target voltage and the target current. The target voltage is the rated voltage of the battery cluster; Target current The following relationship must be satisfied: in, α The current attenuation coefficient is... This represents the current number of the first battery cluster. This is the minimum allowable charging current among the current allowable charging currents of each first 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. 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.

2. The method as described in claim 1, characterized in that, The method further includes: After determining to enter the discharge mode, if the first difference is greater than the target threshold, then after determining that the forced discharge conditions are met, it is determined to enter the forced discharge mode, and a power-on command is sent to the main controller corresponding to the highest first voltage, so that the main controller responds to the power-on command to control the first battery cluster corresponding to the highest first voltage to connect to the high voltage DC circuit. Once it is determined that the first battery cluster 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. The VCU receives a load high-voltage power-on command in response to the load high-voltage command, and controls the target vehicle load component indicated by the load high-voltage power-on command to connect to the high-voltage DC circuit; so that the first battery cluster supplies power to the target vehicle load component through the high-voltage DC circuit.

3. The method as described in claim 1 or 2, characterized in that, The method further includes: During the process of the first battery cluster supplying power to the target vehicle load component through the high-voltage DC circuit, when it is determined that the discharge end condition is met, a current adjustment command is sent to the main controller corresponding to each first battery cluster, so that each main controller responds to the current adjustment command to control the corresponding first battery cluster to adjust the discharge current output to the high-voltage DC circuit to the rated discharge minimum value. When the power-down conditions are met, control each of the target vehicle-mounted load components to disconnect from the high-voltage DC circuit; After determining that each of the target vehicle-mounted load components is disconnected from the high-voltage DC circuit, a battery cluster power-off command is sent to each of the main controllers, so that each of the main controllers disconnects the corresponding first battery cluster from the high-voltage DC circuit in response to the battery cluster power-off command.

4. The method as described in claim 1, characterized in that, The step of charging the first battery cluster via the high-voltage DC circuit and supplying power to the non-power system load components via the high-voltage DC circuit through signaling interaction with the charger includes: The main charging switch corresponding to the high-voltage DC circuit is closed, and a charging ready message is sent to the charger; the charger receives the power supply current output by the charger in response to the charging ready message through the high-voltage DC circuit, charges the first battery cluster, and supplies power to the non-power system load components.

5. The method as described in claim 4, characterized in that, During the charging process of the first battery cluster, the method further includes: When it is determined that there is a second battery cluster in each of the first 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 power supply current output to the high voltage DC circuit to the rated minimum current value of the charger. When the power-off conditions are met, a de-cluster command is sent to the main controller corresponding to the second battery cluster, so that the main controller disconnects the second battery cluster from the high-voltage DC circuit in response to the de-cluster command.

6. The method as described in claim 1, characterized in that, The method further includes: When the charging end condition is met, a current adjustment command is sent to the charger to request the charger to adjust the current value of the power supply 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. After confirming that the main charging switch component is open, the charging mode is exited, and the components connected to the high-voltage DC circuit are disconnected from the high-voltage DC circuit; wherein, the components connected to the high-voltage DC circuit include at least the non-power system load components; The charging termination conditions include: determining that no first battery cluster is connected to the high-voltage DC circuit whenever the number of the first battery cluster changes; or receiving a charging termination command.

7. The method as described in claim 3, characterized in that, The power-off conditions include: the current value 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.

8. The method as described in claim 5 or 6, characterized in that, The power-off conditions include: the current value 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.

9. 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 VCU 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 control method as described in any one of claims 1-8 through signaling interaction with each of the main controllers and the VCU.

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