Vehicle battery pack charging control method, system, and device

Abstract

This application discloses a vehicle battery pack charging control method, system, and device, relating to the field of automotive power battery charging technology. The vehicle battery pack includes multiple battery modules connected in series. The method includes: determining a target number of battery modules to be isolated in the vehicle battery pack based on the maximum output voltage of the charging pile, the voltage information of each battery module in the vehicle battery pack, and a preset low-voltage charging matching coefficient; if the target number is greater than zero, determining a target isolation module set from the battery modules in the vehicle battery pack based on the target number and the voltage information of each battery module in the vehicle battery pack; performing a module bypass operation on each battery module in the target isolation module set so that the remaining battery modules in the vehicle battery pack, excluding the target isolation module set, remain connected in series and are connected to the main charging circuit of the vehicle battery pack; and controlling the charging pile to charge the remaining battery modules through the main charging circuit.

Description

Technical Field

[0001] This application relates to the field of automotive power battery charging technology, and in particular to a vehicle battery pack charging control method, system and device. Background Technology

[0002] With the increasing prevalence of high-voltage platforms (such as 800V and above) in new energy vehicles, the voltage incompatibility between high-voltage battery packs and the large number of existing low-voltage charging piles (such as 400V) is becoming increasingly prominent. Related solutions mainly fall into two categories: one uses a series-parallel topology switching method for battery modules, but this method carries the risk of circulating currents and short-circuit currents that can cause contactor burnout and adhesion during parallel connection; the other uses a high-power on-board boost DC-DC converter, but this solution increases the complexity and size of the vehicle structure, resulting in high hardware costs and significant energy loss. Summary of the Invention

[0003] The embodiments of this application provide a vehicle battery pack charging control method, system and device. By dynamically calculating the number of modules that need to be isolated and adopting a fully series module rotation charging method, the low-voltage charging pile can safely and efficiently charge the high-voltage battery pack without adding a DC-DC boost converter and completely avoiding the risk of parallel circulating current.

[0004] The summary section introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. This summary section is not intended to limit the key and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0005] This application specifically includes the following aspects: In a first aspect, this application proposes a vehicle battery pack charging control method, wherein the vehicle battery pack includes multiple battery modules connected in series, and the method includes: Based on the maximum output voltage of the charging pile, the voltage information of each battery module in the vehicle battery pack, and the preset low-voltage charging matching coefficient, the target number of battery modules to be isolated in the vehicle battery pack is determined. If the target quantity is greater than zero, then based on the target quantity and the voltage information of each battery module in the vehicle battery pack, a target isolation module set is determined from each battery module in the vehicle battery pack. Perform a module bypass operation on each battery module in the target isolation module set so that the remaining battery modules in the vehicle battery pack other than the target isolation module set are connected in series to the main charging circuit of the vehicle battery pack. The charging pile is controlled to charge the remaining battery module through the main charging circuit.

[0006] In one feasible implementation, determining the target number of battery modules to be isolated in the vehicle battery pack based on the maximum output voltage of the charging pile, the voltage information of each battery module in the vehicle battery pack, and a preset low-voltage charging matching coefficient includes: Based on the voltage information of each battery module in the vehicle battery pack, the current charging voltage requirement of the vehicle battery pack is determined. The maximum safe matching voltage of the vehicle battery pack is determined by multiplying the maximum output voltage of the charging pile with the preset low-voltage charging matching coefficient. If the current charging demand voltage is greater than the maximum safe adaptation voltage, then the target quantity is determined to be greater than zero, and the target quantity is determined based on the difference between the current charging demand voltage and the maximum safe adaptation voltage. If the current charging demand voltage is less than or equal to the maximum safe adaptation voltage, then the target quantity is determined to be zero.

[0007] In one feasible implementation, determining the target quantity based on the difference between the current charging demand voltage and the maximum safe adaptation voltage includes: The difference between the current charging demand voltage and the maximum safe adaptation voltage is determined as the voltage to be reduced for the vehicle battery pack. Determine the ratio of the voltage to be reduced to the rated voltage of a single battery module; The target quantity is obtained by rounding the ratio up.

[0008] In one feasible implementation, after determining that the target quantity is zero, the method further includes: All battery modules of the vehicle battery pack are connected in series before being connected to the main charging circuit. The charging pile is controlled to charge all battery modules through the main charging circuit.

[0009] In one feasible implementation, the vehicle battery pack includes multiple isolation modules, each isolation module including a main circuit contactor and a bypass contactor. Each isolation module corresponds one-to-one with a battery module. The step of performing a module bypass operation on each battery module in the target isolation module set includes: For each target battery module in the target isolation module set, the main circuit contactor in the isolation module corresponding to the target battery module is opened, and the bypass contactor in the isolation module corresponding to the target battery module is closed, so as to isolate the target battery module from the main charging circuit.

[0010] In one feasible implementation, it further includes: Repeat the update operation for the remaining battery modules until the preset charging end condition is met, where: The update operation of the remaining battery module includes: determining a first battery module from all the remaining battery modules and determining a second battery module from the target isolated module set; performing a module bypass operation on the first battery module and connecting the second battery module to the main charging circuit to update the remaining battery module; and continuing charging based on the updated remaining battery module. The preset charging termination conditions include: the difference between the current voltage of the first battery module and the current voltage of the second battery module is less than a preset voltage threshold; or, the current voltage of all battery modules in the vehicle battery pack reaches the charging cutoff voltage.

[0011] In one feasible implementation, determining the first battery module from all the remaining battery modules and determining the second battery module from the target isolated module set includes: The battery module with the highest current voltage among the remaining battery modules is identified as the first battery module. The battery module with the lowest current voltage in the target isolation module set is identified as the second battery module.

[0012] In one feasible implementation, the step of performing a module bypass operation on the first battery module and connecting the second battery module to the main charging circuit includes: Control the current in the main charging circuit to drop below the safe current value; The main circuit contactor of the isolation module corresponding to the first battery module is disconnected, and the bypass contactor of the isolation module corresponding to the first battery module is closed. The main circuit contactor of the isolation module corresponding to the second battery module is closed, and the bypass contactor of the isolation module corresponding to the second battery module is opened, so as to connect the second module to the main charging circuit.

[0013] Secondly, this application also proposes a vehicle high-voltage battery pack charging control system, wherein the vehicle battery pack includes multiple battery modules connected in series, and the system includes: The voltage matching calculation module is used to determine the target number of battery modules to be isolated in the vehicle battery pack based on the maximum output voltage of the charging pile, the voltage information of each battery module in the vehicle battery pack, and the preset low-voltage charging matching coefficient, wherein the current charging demand voltage of the vehicle battery pack is greater than the maximum output voltage of the charging pile. An isolation module selection module is used to determine a target isolation module set from the battery modules of the vehicle battery pack based on the target quantity and the voltage information of each battery module in the vehicle battery pack. An isolation execution module is used to perform a module bypass operation on each battery module in the target isolation module set, so that the remaining battery modules in the vehicle battery pack other than the target isolation module set are connected in series to the main charging circuit of the vehicle battery pack. The charging start-up module is used to control the charging pile to charge the remaining battery module through the main charging circuit.

[0014] Thirdly, this application also proposes an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program stored in the memory to implement the steps of the vehicle battery pack charging control method as described in any of the first aspects above.

[0015] This application proposes a vehicle battery pack charging control method. The vehicle battery pack includes multiple battery modules connected in series. This series structure provides a structural basis for reducing the total voltage of the battery pack connected to the main charging circuit through module isolation. First, the target number of modules to be isolated is determined based on the maximum output voltage of the charging pile, the voltage information of each battery module, and a preset low-voltage charging matching coefficient. The preset low-voltage charging matching coefficient provides a safety margin for the maximum output voltage of the charging pile during calculation, ensuring that the total voltage of the remaining modules after isolation corresponding to the calculated target number is strictly lower than the voltage that the charging pile can safely output, thus avoiding the actual charging voltage exceeding the upper limit of the charging pile's output capacity due to voltage fluctuations or calculation errors. If the calculated target number is greater than 0, it indicates that the charging voltage required by the vehicle battery pack is greater than the voltage that the charging pile can safely output. In this case, based on the target number and the voltage information of each battery module, a set of battery modules to be isolated is selected from the multiple battery modules. This selection process is based on the differentiated distribution of the current voltage of each battery module, allowing for flexible determination of the isolation targets according to the current voltage of each battery module. Subsequently, a bypass operation is performed on each battery module in the target isolated module set, temporarily disconnecting these battery modules from the main charging circuit. The remaining unselected battery modules continue their original series connection and are connected to the main charging circuit. At this point, only the remaining battery modules exist in series in the entire main charging circuit, with no parallel structure. This fundamentally eliminates the inherent risks of parallel topologies, such as circulating currents and short-circuit currents leading to contactor burnout and adhesion. Finally, the charging pile directly charges the remaining battery modules through the main charging circuit. Since the total voltage of the remaining battery modules has been reduced to a range that the charging pile can safely support through the above isolation operation, the charging pile can directly output power without relying on the on-board boost DC-DC converter. This completely eliminates the need for the boost DC-DC converter and its associated silicon carbide devices, inductors, and heat dissipation structures, significantly reducing the overall vehicle hardware cost and avoiding energy losses during power electronic conversion, thus significantly improving charging efficiency. Meanwhile, the target number in this method is dynamically calculated based on the maximum output voltage of the charging pile. Different charging pile voltages correspond to different target numbers, so it can be adapted to various low-voltage charging piles of different voltage levels without the need to modify or upgrade the existing charging infrastructure.

[0016] The vehicle battery pack charging control method, system, and device proposed in this application, along with other advantages, objectives, and features of this application, will be partly apparent from the following description and partly understood by those skilled in the art through study and practice of this application. Attached Figure Description

[0017] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit this specification. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A flowchart illustrating a vehicle battery pack charging control method provided in an embodiment of this application; Figure 2 This application provides a schematic diagram of isolated charging of a battery module. Figure 3 This application provides a schematic diagram of the functional modules of a vehicle high-voltage battery pack charging control system. Figure 4 This is a schematic diagram of the structure of a vehicle battery pack charging control device provided in an embodiment of this application. Detailed Implementation

[0018] To better understand the technical solutions provided in the embodiments of this specification, the technical solutions of the embodiments of this specification will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of this specification and the specific features in the embodiments are detailed descriptions of the technical solutions of the embodiments of this specification, rather than limitations on the technical solutions of this specification. In the absence of conflict, the embodiments of this specification and the technical features in the embodiments can be combined with each other.

[0019] In this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, without necessarily requiring or implying any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. The term "two or more" includes two or more cases.

[0020] This application provides a vehicle battery pack charging control method, wherein the vehicle battery pack includes multiple battery modules connected in series. For example... Figure 1 As shown, the method may include: S110. Based on the maximum output voltage of the charging pile, the voltage information of each battery module in the vehicle battery pack, and the preset low-voltage charging matching coefficient, determine the target number of battery modules to be isolated in the vehicle battery pack.

[0021] For example, firstly, the maximum output voltage of the charging pile (i.e., the highest DC voltage value that the charging pile can output) is obtained, and the voltage information of each battery module in the vehicle's high-voltage battery pack is collected through the Battery Management Unit (BMU). This voltage information includes the rated voltage and the current charging demand voltage. Then, based on the maximum output voltage of the charging pile, the voltage information of each battery module, and a preset low-voltage charging matching coefficient, the target number K of battery modules that need to be isolated (i.e., bypassed) from the main charging circuit is calculated using the following formula: K = ceil(( - × )÷ ),in The current charging voltage required by the battery pack. This is the maximum output voltage of the charging station. To preset the low-voltage charging matching coefficient, Here, 'ceil' represents the rated voltage of a single battery module, and 'ceil' is the floor function. The physical meaning of this formula is: when the current charging voltage demand of the battery pack is too high and the charging pile's output voltage is insufficient, some battery modules need to be removed from the series main circuit (i.e., isolated) to reduce the total charging voltage demand of the remaining modules to a range that the charging pile can safely support. Floor function ensures that the total charging voltage demand of the remaining battery modules strictly does not exceed the product of the charging pile's maximum output voltage and a safety factor, thus guaranteeing the safety of the charging process. Specifically, the BMU collects information such as the voltage status of the cells in each battery module (N in total) through the Cell Monitoring Controller (CMC) to obtain the current charging voltage demand of each battery module. (i=1, 2, ..., N). Then, the BMU adds up the current charging demand voltage of all battery modules to obtain the current charging demand voltage of the vehicle battery pack. =Σ The current charging voltage required for the vehicle's battery pack. This reflects the actual voltage level of the vehicle's battery pack at the current moment.

[0022] S120. If the target quantity is greater than zero, then based on the target quantity and the voltage information of each battery module in the vehicle battery pack, determine the target isolation module set from each battery module in the vehicle battery pack.

[0023] For example, after calculating the target quantity K, it is determined whether the target quantity is greater than zero. If K is greater than zero, it means that the maximum output voltage of the current charging pile is insufficient to directly charge the entire battery pack, and module isolation is required. At this time, based on the target quantity K and the voltage information of each battery module, it is determined which battery modules need to be isolated from the multiple battery modules in the battery pack. For example, all battery modules are sorted from highest to lowest current charging demand voltage, and the K battery modules with the highest current charging demand voltage are selected as the target isolation module set, because these battery modules need to be preferentially connected for charging in subsequent rotation charging. The determined target isolation module set is denoted as... It contains K battery modules.

[0024] S130. Perform a module bypass operation on each battery module in the target isolation module set so that the remaining battery modules in the vehicle battery pack, excluding the target isolation module set, are connected in series to the main charging circuit of the vehicle battery pack.

[0025] For example, for the target isolation module set Each battery module in the battery pack undergoes a module bypass operation, which means that by controlling the switching device in the corresponding isolation module, the battery module is physically isolated from the main charging circuit (i.e., bypassed), preventing current from flowing through it. After the bypass operation is performed, the battery pack contains only... The remaining battery modules (denoted as) The remaining battery modules (NK, where N is the total number of battery modules in the pack) remain connected in series and are connected to the main charging circuit of the vehicle's battery pack. It should be noted that throughout the entire charging process, the remaining battery modules remain connected in series, with no parallel structure. This fundamentally eliminates the inherent risks of parallel topologies, such as circulating currents and short-circuit currents leading to contactor burnout and adhesion.

[0026] S140: Control the charging pile to charge the remaining battery modules through the main charging circuit.

[0027] For example, after the remaining battery module is connected to the main charging circuit, the BMU calculates the total charging voltage required by the remaining battery module. ,in, = -K× And through the charging control unit (CCU), it requests a connection to the charging station. Matched charging voltage. After receiving the request, the charging station charges the remaining battery module through the main charging circuit. Since the total charging voltage requirement of the remaining battery module has been reduced to a range that the charging station can safely support, the charging process can proceed normally without relying on a DC-DC converter for boost conversion.

[0028] In some examples, the target number of battery modules to be isolated in the vehicle battery pack is determined based on the maximum output voltage of the charging pile, the voltage information of each battery module in the vehicle battery pack, and a preset low-voltage charging matching coefficient, including: Based on the voltage information of each battery module in the vehicle battery pack, determine the current charging voltage requirement of the vehicle battery pack. The maximum safe matching voltage of the vehicle battery pack is determined by multiplying the maximum output voltage of the charging pile with the preset low-voltage charging matching coefficient. If the current charging demand voltage is greater than the maximum safe adaptation voltage, the target quantity is determined to be greater than zero, and the target quantity is determined based on the difference between the current charging demand voltage and the maximum safe adaptation voltage. If the current charging voltage requirement is less than or equal to the maximum safe adaptation voltage, then the target quantity is determined to be zero.

[0029] For example, the maximum output voltage of the charging pile Matching coefficient with preset low-voltage charging Multiply by these to obtain the maximum safe operating voltage of the vehicle's battery pack. = × . The value is less than 1 (e.g., 0.90 to 0.98), and its purpose is to provide a safety margin of 2% to 10%. This safety margin is necessary because during charging, the battery module's charging voltage demand gradually increases. If calculated based on 100% of the charging pile's maximum output voltage, the battery module voltage increase towards the end of charging may exceed the charging pile's output capacity, leading to charging interruption or equipment damage. Therefore, the maximum safe adaptation voltage is actually the highest charging voltage that the charging pile can support while ensuring safety.

[0030] The current charging voltage required by the battery pack. With maximum safe matching voltage Compare. If > This indicates that the total charging voltage demand of the current battery pack exceeds the upper voltage limit that the charging pile can safely support, therefore it is necessary to isolate a portion of the battery modules from the battery pack. At this time, based on... and The difference is then used to further calculate the specific value of K. If ≤ This indicates that the output voltage of the charging pile is sufficient to cover the current charging voltage requirement of the battery pack, and there is no need to perform module isolation operation. At this time, the target quantity K is zero, and the entire battery pack can be charged directly.

[0031] In some examples, the target quantity is determined based on the difference between the current charging demand voltage and the maximum safe adaptation voltage, including: The difference between the current charging voltage requirement and the maximum safe adaptation voltage is determined as the voltage to be reduced for the vehicle battery pack. Determine the ratio of the voltage to be reduced to the rated voltage of a single battery module; The comparison value is rounded up to obtain the target quantity.

[0032] For example, the current charging voltage required by the battery pack. With maximum safe matching voltage The difference is determined as the voltage to be reduced. = - The voltage to be reduced indicates the voltage value that needs to be removed from the main charging circuit in order to reduce the equivalent series voltage of the battery pack to a range that the charging station can safely support.

[0033] Calculate the voltage to be reduced With the rated voltage of a single battery module The ratio R = ÷ This ratio represents the theoretical number of battery modules that need to be isolated, but since this ratio is usually not an integer, the ratio R is rounded up (using the ceil function) to obtain the target number K = ceil(R). Rounding up instead of rounding to the nearest integer or down ensures that the total charging voltage demand of the remaining battery modules strictly does not exceed the maximum safe adaptation voltage. Specifically, if R = 5.25, rounding up gives K = 6, and the total charging voltage demand of the remaining battery modules... = -6× This value must be less than or equal to If we round down to get K=5, then the total charging voltage required for the remaining battery module is... = -5× It may still be greater than This can lead to overload of the charging station. Meanwhile, rounding up to obtain K is the smallest integer that satisfies the safety constraints. Isolating fewer battery modules (K-1) does not meet the safety constraints, while isolating more battery modules (K+1), although safe, unnecessarily reduces the number of battery modules participating in charging, thus lowering the single-charge capacity. Therefore, rounding up maximizes the single-charge capacity while ensuring safety.

[0034] In some examples, after determining that the target quantity is zero, the method also includes: All battery modules of the vehicle's battery pack are connected in series before being connected to the main charging circuit. The charging station is controlled to charge all battery modules through the main charging circuit.

[0035] For example, when the BMU determines the current charging voltage requirement... Less than or equal to the maximum safe adaptation voltage At this point, the target quantity K is set to 0, and no battery modules need to be isolated. Subsequently, the BMU controls all battery modules in the vehicle's battery pack to maintain their original series connection (i.e., all main circuit contactors of all battery modules remain closed, and bypass contactors remain open), and connects the complete battery pack to the main charging circuit. The CCU requests the voltage required for the current charging of the battery pack from the charging station. With the matching charging voltage, the charging station charges all battery modules through the main charging circuit.

[0036] This mode is suitable for scenarios where the charging pile has a high output voltage capability. For example, when an 800V high-voltage battery pack is connected to a charging pile with a maximum output voltage of 1000V, the output voltage of the charging pile is sufficient to cover the entire voltage requirement of the battery pack, without any voltage reduction adaptation. In this case, all battery modules remain connected in series, and the charging process is exactly the same as conventional high-voltage charging.

[0037] In some examples, the vehicle battery pack includes multiple isolation modules, each comprising a main circuit contactor and a bypass contactor. Each isolation module corresponds one-to-one with a battery module, performing a module bypass operation on each battery module in the target isolation module set, including: For each target battery module in the target isolation module set, the main circuit contactor in the isolation module corresponding to the target battery module is opened, and the bypass contactor in the isolation module corresponding to the target battery module is closed, so as to isolate the target battery module from the main charging circuit.

[0038] For example, such as Figure 2As shown, the vehicle battery pack includes multiple isolation modules, each corresponding to a battery module. Each isolation module contains a main circuit contactor Kn1 (i.e., a high-voltage contactor connected in series in the positive or negative circuit of the battery module) and a bypass contactor Kn2 (i.e., a high-voltage contactor connected in series in the bypass circuit), as well as a mechanical interlocking mechanism to ensure that the main circuit contactor and the bypass contactor do not close simultaneously.

[0039] For the target isolation module set For each target battery module, the BMU sends an isolation command to the corresponding isolation module. Upon receiving the isolation command, the isolation module performs the following actions within a preset time (e.g., ≤30ms): it controls the main circuit contactor Kn1 to open, preventing the target battery module from being connected in series in the main charging circuit; simultaneously, it controls the bypass contactor Kn2 to close, allowing current to bypass the target battery module through the bypass circuit. Through the coordinated action of these two contactors, the target battery module is physically isolated from the main charging circuit and no longer participates in charging.

[0040] It should be noted that a current-limiting resistor is connected in series in the closed loop of the bypass contactor Kn2 of each isolation module. The current-limiting resistor The function of the current-limiting resistor is to limit the inrush current flowing through the bypass circuit at the instant the bypass contactor Kn2 closes, preventing damage to the contactor contacts caused by current spikes due to capacitive loads. The current-limiting resistor employs an adjustable resistor structure, and its resistance value is dynamically adjusted by the BMU based on the absolute value ΔV of the difference between the rated voltage of the isolated individual battery module and the output voltage of the charging pile. When ΔV > 50V, the current-limiting resistor is set to a high setting (e.g., 200Ω) to prioritize limiting the inrush current and protecting the contactor contacts; when 20V ≤ ΔV ≤ 50V, the current-limiting resistor is set to a medium setting (e.g., 50Ω) to balance charging speed and safety; when ΔV < 20V, the current-limiting resistor is set to a low setting (e.g., 10Ω) to increase charging power and shorten recharging time.

[0041] The BMU can also employ a proportional-integral-derivative (PID) closed-loop continuous control method. Using the target charging current as the setpoint, it adjusts the adjustable resistor through pulse width modulation (PWM) to ensure the actual charging current tracks the target charging current, achieving constant current charging. This current-limiting resistor is independently set in each bypass loop, enabling each isolated battery module to achieve independent controlled charging.

[0042] After the bypass contactor Kn2 closes, the current bypasses the isolated battery module through the bypass circuit (including the current-limiting resistor), thereby removing the battery module from the main charging circuit. Simultaneously, the mechanical interlock mechanism ensures that the main circuit contactor Kn1 and the bypass contactor Kn2 in the same isolation module will not close simultaneously. If both close at the same time, it will cause a short circuit in the battery module, potentially leading to a serious safety accident. The mechanical interlock mechanism physically eliminates this risk.

[0043] In some examples, the method also includes: Repeat the update operation for the remaining battery modules until the preset charging end condition is met, where: The remaining battery module update operation includes: determining a first battery module from all remaining battery modules and determining a second battery module from the target isolated module set; performing a module bypass operation on the first battery module and connecting the second battery module to the main charging circuit to update the remaining battery module; and continuing charging based on the updated remaining battery module. The preset charging termination conditions include: the difference between the current voltage of the first battery module and the current voltage of the second battery module is less than a preset voltage threshold; or, the current voltage of all battery modules in the vehicle battery pack reaches the charging cutoff voltage.

[0044] For example, when the vehicle battery pack enters the low-voltage isolated charging mode (i.e., the target isolated module set) (Non-empty) The charging process is not simply about fully charging the remaining modules at once and then ending, but rather about achieving balanced charging of all modules by repeatedly executing the "remaining battery module update operation".

[0045] Specifically, the update operation of the remaining battery modules includes: in the current charging state, from the set of remaining battery modules... Select one battery module as the first battery module, and select it from the target isolated module set. Select one battery module as the second battery module.

[0046] Then, a module bypass operation is performed on the first battery module, isolating it from the main charging circuit; simultaneously, the second battery module is connected to the main charging circuit (i.e., the main circuit contactor in the isolation module corresponding to the second battery module is closed and the bypass contactor is opened), allowing it to participate in series charging again. Through this "one in, one out" alternating operation, the remaining battery modules are... and target isolation module set Updated, i.e., the first battery module from move in The second battery module from move in .

[0047] After completing the module rotation, the BMU recalculates the updated set of remaining battery modules. Total charging voltage required The CCU requests a connection with the charging station. The matched charging voltage continues to charge the updated remaining modules. This update operation is repeated until a preset charging termination condition is met. The preset charging termination condition includes one of the following two scenarios: Termination condition 1: In each update operation, the first battery module (i.e., the current...) The current voltage of the battery module with the highest voltage in the middle is compared with that of the second battery module (i.e., the current voltage of the second battery module). The voltage difference between the current voltage of the battery module with the lowest voltage is less than a preset voltage threshold (e.g., 50mV). This means that the voltage difference between the two sets has been reduced to an acceptable range, and the voltages of all battery modules are becoming consistent, eliminating the need for further rotation.

[0048] Termination condition two: All battery modules in the vehicle battery pack (including) and If the current voltage of all battery modules has reached the charging cut-off voltage (i.e., the full charge voltage specified by the battery manufacturer), it means that all battery modules are fully charged and the charging process can be ended.

[0049] In some examples, a first battery module is determined from all remaining battery modules, and a second battery module is determined from the target isolated module set, including: The battery module with the highest current voltage among the remaining battery modules is identified as the first battery module. The battery module with the lowest current voltage in the target isolation module set is identified as the second battery module.

[0050] For example, the BMU first obtains the set of remaining battery modules. The current voltage of each battery module is determined, and the battery module with the highest current voltage is selected as the first battery module. This battery module will be isolated from the main charging circuit because it has already received a significant amount of charging, its voltage is high, and it does not need further charging for the time being. Then, the target set of isolated modules is obtained. The system calculates the current voltage of each battery module and selects the module with the lowest current voltage as the second battery module. This second battery module will be connected to the main charging circuit because it receives less charging and has a lower voltage, thus requiring connection to receive charging. This "high-voltage-plus-low-voltage" selection strategy, which alternates between the highest-voltage online battery module and the lowest-voltage offline battery module, can most effectively reduce the voltage difference between the two sets, achieving balanced charging of all modules with the fewest number of rotations.

[0051] In some examples, a module bypass operation is performed on the first battery module, and the second battery module is connected to the main charging circuit, including: Control the current in the main charging circuit to drop below the safe current value; The main circuit contactor of the isolation module corresponding to the first battery module is disconnected, and the bypass contactor of the isolation module corresponding to the first battery module is closed. The main circuit contactor of the isolation module corresponding to the second battery module is closed, and the bypass contactor of the isolation module corresponding to the second battery module is opened, so as to connect the second module to the main charging circuit.

[0052] For example, during battery module switching operations, the relevant contactors need to be controlled according to a specific timing sequence to ensure the safety and reliability of the operation. Specifically, before starting the battery module switching operation, the CCU first notifies the charging pile to pause charging output, allowing the current in the main charging circuit to gradually decrease to below a safe current value (e.g., below 10A). This is to prevent arcing or burning of the contacts due to high current when the contactors operate. Opening or closing the contactor under high current conditions will generate a strong arc, which can not only damage the contactor contacts but also potentially cause serious safety accidents such as fires. Therefore, the contactor switching operation must only be performed after the current has dropped below the safe value.

[0053] After the main charging circuit current drops below a safe value, the BMU sends an isolation command to the isolation module corresponding to the first battery module. This isolation module first disconnects the main circuit contactor Kn1 (disconnecting the first module from the series main circuit), and then closes the bypass contactor Kn2 (allowing current to bypass the first module through the bypass circuit). There is a very short time interval between these two actions (guaranteed by a mechanical interlock mechanism) to ensure that Kn2 closes only after Kn1 is completely disconnected, preventing both from conducting simultaneously and causing a short circuit in the module.

[0054] After the first battery module is successfully isolated, the BMU sends a recovery command to the isolation module corresponding to the second battery module. This isolation module first disconnects the bypass contactor Kn2 (removing the second module from the bypass state), and then closes the main circuit contactor Kn1 (reconnecting the second module to the main charging circuit in series). Similarly, there is a very short time interval between the two actions, ensuring that Kn1 closes only after Kn2 is completely disconnected, preventing both from conducting simultaneously and causing a short circuit in the module. After completing the above operations, the second module is successfully connected to the main charging circuit, and the switching operation is complete.

[0055] It should be noted that the aforementioned contactor control timing is crucial for ensuring the safety of the switching operation. During the process of isolating one battery module and connecting another, at no time should two battery modules be simultaneously in an uncertain "switching" state, nor should the main circuit contactor and bypass contactor of any battery module be simultaneously closed. The mechanical interlock mechanism physically ensures the impossibility of the latter, while the aforementioned control timing logically ensures the safety of the former.

[0056] Furthermore, the above method may encounter abnormal situations such as communication interruption, actuator failure, abnormal temperature, or mechanical interlock failure during execution. Specifically, during charging, when the CCU detects a communication interruption with the charging pile, it immediately stops charging and maintains the current state of each fault isolation module to avoid malfunctions due to unknown states before communication is restored. Simultaneously, it records fault codes and alerts the user via the instrument panel. When the BMU detects that any isolation module has timed out or that the feedback contactor status does not match the command, it immediately stops charging and records a fault code. For serious feedback errors (such as contactor jamming), the BMU directly controls the main positive and negative relays to disconnect, physically severing the electrical connection between the battery pack and the external high-voltage circuit. During charging, the BMU monitors the temperature of each connected battery module in real time via the CMC. When the temperature of any connected battery module exceeds a preset temperature threshold (e.g., 60°C), charging is immediately suspended and resumed after the temperature drops. If the temperature continues to rise, the battery module is permanently isolated and will no longer participate in subsequent charging. In addition, the BMU monitors the on / off status of the main circuit contactor Kn1 and bypass contactor Kn2 in each isolation module in real time through the auxiliary contacts of each contactor. When it is detected that both are closed or open at the same time, it is determined that the mechanical interlock has failed, the main positive relay and the main negative relay are immediately disconnected, and a serious fault is reported.

[0057] Furthermore, this application also proposes a vehicle high-voltage battery pack charging control system, an embodiment for executing any of the above-described vehicle high-voltage battery pack charging control methods, specifically as follows: Figure 3 The diagram shown is a functional block diagram of a vehicle high-voltage battery pack charging control system proposed in this application. The system includes: The voltage matching calculation module 21 is used to determine the target number of battery modules to be isolated in the vehicle battery pack based on the maximum output voltage of the charging pile, the voltage information of each battery module in the vehicle battery pack and the preset low-voltage charging matching coefficient, wherein the current charging demand voltage of the vehicle battery pack is greater than the maximum output voltage of the charging pile. The isolation module selection module 22 is used to determine the target isolation module set from the battery modules in the vehicle battery pack based on the target quantity and the voltage information of each battery module in the vehicle battery pack. The isolation execution module 23 is used to perform module bypass operation on each battery module in the target isolation module set so that the remaining battery modules in the vehicle battery pack other than the target isolation module set are connected in series and then connected to the main charging circuit of the vehicle battery pack. The charging start module 24 is used to control the charging pile to charge the remaining battery module through the main charging circuit.

[0058] It should be noted that the above embodiments are merely best examples and are not intended to limit the implementation of this application.

[0059] Furthermore, such as Figure 4 As shown, this application embodiment also provides an electronic device 300, including a processor 310, a memory 320, and a computer program 321 stored in the memory 320 and executable on the processor. When the processor 310 executes the computer program 321, it implements the steps of any of the above-described vehicle battery pack charging control methods.

[0060] Since the electronic device described in this embodiment is the device used to implement a vehicle battery pack charging control method in the embodiments of this application, those skilled in the art can understand the specific implementation method and various variations of the electronic device in this embodiment based on the method described in the embodiments of this application. Therefore, how the electronic device implements the method in the embodiments of this application will not be described in detail here. Any device used by those skilled in the art to implement the method in the embodiments of this application falls within the scope of protection of this application.

[0061] In practical implementation, when the computer program 321 is executed by the processor, it can achieve the following: Figure 1 Any of the corresponding implementation methods in the embodiments.

[0062] It should be noted that the descriptions of each embodiment in the above embodiments have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0063] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-readable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-readable program code.

[0064] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create a machine for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0065] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0066] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0067] This application also provides a computer program product, which includes computer software instructions that, when executed on a processing device, cause the processing device to execute the process of a vehicle battery pack charging control method.

[0068] A computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the flow or function according to the embodiments of this application is generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that a computer can store or a data storage device such as a server or data center that integrates one or more available media. The available medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state disk (SSD)).

[0069] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0070] In the several embodiments provided in this application, it should be understood that the disclosed devices, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, or indirect coupling or communication connection between devices or units, and may be electrical, mechanical, or other forms.

[0071] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0072] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0073] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0074] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

[0075] Although preferred embodiments have been described in this specification, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this specification.

[0076] Obviously, those skilled in the art can make various modifications and variations to this specification without departing from its spirit and scope. Therefore, if such modifications and variations fall within the scope of the claims and their equivalents, this specification is also intended to include such modifications and variations.

Claims

1. A method for controlling the charging of a vehicle battery pack, characterized in that, The vehicle battery pack includes multiple battery modules connected in series, and the method includes: Based on the maximum output voltage of the charging pile, the voltage information of each battery module in the vehicle battery pack, and the preset low-voltage charging matching coefficient, the target number of battery modules to be isolated in the vehicle battery pack is determined. If the target quantity is greater than zero, then based on the target quantity and the voltage information of each battery module in the vehicle battery pack, a target isolation module set is determined from each battery module in the vehicle battery pack. Perform a module bypass operation on each battery module in the target isolation module set so that the remaining battery modules in the vehicle battery pack other than the target isolation module set are connected in series to the main charging circuit of the vehicle battery pack. The charging pile is controlled to charge the remaining battery module through the main charging circuit.

2. The method according to claim 1, characterized in that, The method for determining the target number of battery modules to be isolated in the vehicle battery pack, based on the maximum output voltage of the charging pile, the voltage information of each battery module in the vehicle battery pack, and a preset low-voltage charging matching coefficient, includes: Based on the voltage information of each battery module in the vehicle battery pack, the current charging voltage requirement of the vehicle battery pack is determined. The maximum safe matching voltage of the vehicle battery pack is determined by multiplying the maximum output voltage of the charging pile with the preset low-voltage charging matching coefficient. If the current charging demand voltage is greater than the maximum safe adaptation voltage, then the target quantity is determined to be greater than zero, and the target quantity is determined based on the difference between the current charging demand voltage and the maximum safe adaptation voltage. If the current charging demand voltage is less than or equal to the maximum safe adaptation voltage, then the target quantity is determined to be zero.

3. The method according to claim 2, characterized in that, Determining the target quantity based on the difference between the current charging demand voltage and the maximum safe adaptation voltage includes: The difference between the current charging demand voltage and the maximum safe adaptation voltage is determined as the voltage to be reduced for the vehicle battery pack. Determine the ratio of the voltage to be reduced to the rated voltage of a single battery module; The target quantity is obtained by rounding the ratio up.

4. The method according to claim 2, characterized in that, After determining that the target quantity is zero, the method further includes: All battery modules of the vehicle battery pack are connected in series before being connected to the main charging circuit. The charging pile is controlled to charge all battery modules through the main charging circuit.

5. The method according to claim 1, characterized in that, The vehicle battery pack includes multiple isolation modules, each isolation module including a main circuit contactor and a bypass contactor. Each isolation module corresponds one-to-one with a battery module. Performing a module bypass operation on each battery module in the target isolation module set includes: For each target battery module in the target isolation module set, the main circuit contactor in the isolation module corresponding to the target battery module is opened, and the bypass contactor in the isolation module corresponding to the target battery module is closed, so as to isolate the target battery module from the main charging circuit.

6. The method according to claim 1, characterized in that, Also includes: Repeat the update operation for the remaining battery modules until the preset charging end condition is met, where: The update operation of the remaining battery module includes: determining a first battery module from all the remaining battery modules and determining a second battery module from the target isolated module set; performing a module bypass operation on the first battery module and connecting the second battery module to the main charging circuit to update the remaining battery module; and continuing charging based on the updated remaining battery module. The preset charging termination conditions include: the difference between the current voltage of the first battery module and the current voltage of the second battery module is less than a preset voltage threshold; or, the current voltage of all battery modules in the vehicle battery pack reaches the charging cutoff voltage.

7. The method according to claim 6, characterized in that, The step of determining the first battery module from all the remaining battery modules and determining the second battery module from the target isolated module set includes: The battery module with the highest current voltage among the remaining battery modules is identified as the first battery module. The battery module with the lowest current voltage in the target isolation module set is identified as the second battery module.

8. The method according to claim 6, characterized in that, The step of performing a module bypass operation on the first battery module and connecting the second battery module to the main charging circuit includes: Control the current in the main charging circuit to drop below the safe current value; The main circuit contactor of the isolation module corresponding to the first battery module is disconnected, and the bypass contactor of the isolation module corresponding to the first battery module is closed. The main circuit contactor of the isolation module corresponding to the second battery module is closed, and the bypass contactor of the isolation module corresponding to the second battery module is opened, so as to connect the second module to the main charging circuit.

9. A vehicle high-voltage battery pack charging control system, characterized in that, The vehicle battery pack includes multiple battery modules connected in series, and the system includes: The voltage matching calculation module is used to determine the target number of battery modules to be isolated in the vehicle battery pack based on the maximum output voltage of the charging pile, the voltage information of each battery module in the vehicle battery pack, and the preset low-voltage charging matching coefficient, wherein the current charging demand voltage of the vehicle battery pack is greater than the maximum output voltage of the charging pile. An isolation module selection module is used to determine a target isolation module set from the battery modules of the vehicle battery pack based on the target quantity and the voltage information of each battery module in the vehicle battery pack. An isolation execution module is used to perform a module bypass operation on each battery module in the target isolation module set, so that the remaining battery modules in the vehicle battery pack other than the target isolation module set are connected in series to the main charging circuit of the vehicle battery pack. The charging start-up module is used to control the charging pile to charge the remaining battery module through the main charging circuit.

10. An electronic device, comprising: The memory and processor are characterized in that the processor is used to implement the steps of the vehicle battery pack charging control method as described in any one of claims 1 to 8 when executing a computer program stored in the memory.

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