Split type direct current charging system and control method

Abstract

This application relates to the field of intelligent control technology, specifically to a split-type DC charging system and control method. The solution obtains the current SOC, SOH, battery voltage state parameters, and limit voltage parameters of each battery, and then determines the target batteries and corresponding target charging terminals for each constant current charging stage whose SOC is greater than a preset first threshold. The target batteries are grouped according to the time remaining before switching to constant voltage charging. Charging terminals with target times less than or equal to the preset time threshold are gradually charged with a smaller second current. This solution effectively avoids drastic fluctuations in the charging module's output power caused by instantaneous power drops during switching. It also ensures timely and effective power utilization, resulting in highly stable total output power and optimized module utilization. Furthermore, it makes the voltage rise of the charging battery smoother when switching, effectively preventing the problem of excessively rapid battery temperature rise near the constant voltage stage.

Description

Technical Field

[0001] This application relates to the field of intelligent control technology, specifically to a split-type DC charging system and control method. Background Technology

[0002] With the rapid development of new energy vehicles, electric vehicles are experiencing explosive growth. As a key supporting technology for electric vehicles, the charging system's performance directly impacts various aspects, including ease of use, charging efficiency, and battery life. The electric vehicle battery charging process can be broadly divided into four stages: trickle charging, constant current charging, constant voltage charging, and trickle float charging. During the constant current stage, the battery is charged with a relatively large current. When the battery voltage reaches a predetermined level, the battery management system (BMS) initiates a constant voltage charging mode via communication messages. At the moment of switching, the charging current decreases from a large value to a smaller value, and then gradually decreases as charging continues until the battery is fully charged.

[0003] Currently, charging systems mainly fall into two categories: separate and integrated. Traditional constant current-constant voltage switching relies on real-time commands from the Battery Management System (BMS). However, for separate charging systems, switching based on real-time BMS commands may result in frequent and severe fluctuations in the charging module's output power due to sudden drops in current during switching, potentially causing system oscillations. Furthermore, battery voltage changes have inertia, especially with aging batteries exhibiting increased internal resistance. Combined with potential communication and sampling delays in separate systems, this leads to lag in response, potentially causing overvoltage during charging. Additionally, as the battery approaches the constant voltage stage, its internal resistance also increases. If high-current charging continues, according to Joule's law, the large current will generate significant heat across the battery's internal resistance, potentially causing the battery to overheat excessively.

[0004] Patent document CN117621896B discloses a method for detecting abnormalities in DC charging. During the constant current and constant voltage charging stages, it estimates the time T1 from the current charging rate to the constant current / constant voltage cutoff point, and compares the corresponding charge D1 at T1 with the theoretical charge Dy to determine if charging is normal. This method provides a solution for checking charging abnormalities by estimating time. However, the charging rate during the constant current stage changes non-linearly, and linear judgment based on the current charging rate will introduce errors. Furthermore, differences in battery aging and communication delays can also have an impact. Summary of the Invention

[0005] Based on this, this application proposes a split-type DC charging system and control scheme to address the above problems, aiming to intelligently, efficiently, and accurately control the split-type DC charging system to ensure efficient, stable, and safe charging.

[0006] This application provides a split-type DC charging system and control method, the method comprising:

[0007] Establish communication connections between each charging terminal and its corresponding battery, and control the charging terminal to charge the corresponding battery.

[0008] The current SOC, SOH, battery voltage state parameters, and limit voltage parameters of each battery are obtained at preset time intervals.

[0009] Identify the target batteries and corresponding target charging terminals whose SOC is greater than a preset first threshold for each constant current charging;

[0010] Calculate the target time for each target battery to switch to constant voltage charging, and group the target charging terminals based on each target time;

[0011] If the target time is less than or equal to a preset time threshold, the corresponding first target charging terminal is controlled to charge the corresponding battery with a second current, wherein the second current is less than the current constant current charging current.

[0012] Furthermore, the above method also includes: if the time information is greater than a preset time threshold, then sending a monitoring instruction to the corresponding charging terminal at a preset time interval;

[0013] If the corresponding communication feedback information is not received within a preset time, the corresponding second target charging terminal is controlled to charge the corresponding battery with the second current.

[0014] Furthermore, the above method also includes: if the feedback time of the corresponding second target terminal exceeds the corresponding target time, then control to stop charging the corresponding second target charging terminal.

[0015] Preferably, determining the time information from the current charging state to constant voltage includes:

[0016] The switching time information from the current charging state to constant voltage is determined based on the current battery SOH, battery voltage, and limit voltage parameters.

[0017] The switching time information is corrected based on the delay compensation parameters.

[0018] Preferably, the second current I satisfies:

[0019]

[0020] Among them, I cc The constant current charging current is t, and the corresponding time parameter is t_t. w This is the corrected switching time information, and β is the adjustment coefficient.

[0021] Furthermore, the above method also includes:

[0022] Record the communication delay time of each charging terminal;

[0023] Based on the communication delay time, the communication security parameters of each charging terminal are adjusted according to a preset period.

[0024] Furthermore, the method also includes:

[0025] Determine the changes in power demand at each port within a future preset time window;

[0026] If the change is greater than a preset value, the corresponding charging power module is controlled.

[0027] A second aspect of this application also provides a split-type DC charging system, the system including a charging control subsystem, multiple charging power modules, and multiple charging terminals, wherein the charging control subsystem includes a control module to control the execution of the steps of any of the methods described above.

[0028] A third aspect of this application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, causes the processor to perform the steps of any of the methods described above.

[0029] A fourth aspect of this application also provides a split-type DC charging control device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of any of the methods described above.

[0030] The fifth aspect of this application provides a computer terminal device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of any of the methods described above.

[0031] The technical solution provided in this application acquires the current SOC, SOH, battery voltage state parameters, and limit voltage parameters of each battery at preset time intervals. This allows for the identification of target batteries with an SOC greater than a preset first threshold and their corresponding target charging terminals for each constant-current charging phase. The target batteries are then grouped according to the time remaining before switching to constant-voltage charging. Charging terminals with target times less than or equal to the preset time threshold are gradually charged with a smaller second current. This solution avoids the rigidity of traditional BMS-based fixed control strategies, effectively preventing drastic fluctuations in charging module output power caused by sudden drops in instantaneous charging power at switching charging terminals. Timely and effective power utilization ensures highly stable total output power and maximizes module utilization. Furthermore, it allows for a smoother voltage rise when the charging battery is switched, reducing the urgency of forced BMS intervention (and potentially even preventing the triggering of limit protection). It also effectively prevents excessively rapid temperature rises of the battery near the constant-voltage stage.

[0032] Furthermore, this application's solution controls the charging current based on the communication response of the corresponding charging terminal while controlling the target time group. This effectively avoids response lag caused by communication delays, which could lead to overvoltage charging runaway. Moreover, this application's solution also considers the battery's State of Health (SOH) characteristics to make targeted predictions of the target time and sets safer time values ​​for aging, enabling high-internal-resistance aging batteries to initiate smooth current reduction earlier, avoiding subsequent overvoltage charging and affecting battery life. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] in:

[0035] Figure 1 A flowchart of a control method for a split-type DC charging system in one embodiment;

[0036] Figure 2 This is a schematic diagram of the charging voltage and charging current control curves in one embodiment;

[0037] Figure 3 This is a structural block diagram of a split-type DC charging system in one embodiment;

[0038] Figure 4 This is a structural block diagram of a split-type DC charging system control device in one embodiment. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] The terms "comprising," "including," and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this application, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such processes, methods, products, or apparatus. Terms such as "first" and "second," and other relational terms, in the claims, specification, and accompanying drawings of this application, are used merely to distinguish one entity / operation / object from another, and do not necessarily require or imply any such actual relationship or order between these entities / operations / objects.

[0041] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase at various points in the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0042] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0043] In one implementation, such as Figure 1 The diagram shown is a flowchart of a control method for a split-type DC charging system according to this application. The method includes:

[0044] S10. Establish communication connections between each charging terminal and its corresponding battery, and control the charging terminal to charge the corresponding battery.

[0045] Specifically, when the charging gun is inserted into the vehicle's charging port, the charging terminal first checks whether the physical connection between the charging gun and the vehicle's charging port is secure and normal. Using a connection detection circuit within the charging gun, it determines whether a complete electrical circuit has been formed. If an abnormal circuit is detected, the charging terminal screen prompts the user to re-insert and re-plug the charging gun to ensure a reliable physical connection.

[0046] At the same time, further check whether the internal pins of the charging gun (such as the positive and negative pins used for power transmission and the CAN bus pins used for communication) are in normal contact to prevent loose connections from affecting subsequent communication and charging functions.

[0047] The charging terminal further identifies the vehicle and battery type, matches them using a pre-stored vehicle communication protocol library, and calls the corresponding protocol parsing module. For vehicles with unknown protocols, it initiates an automatic identification program, sends a general protocol detection request to the vehicle battery management system (BMS), and analyzes and determines the applicable communication protocol based on the BMS's response.

[0048] Furthermore, the system sends a simple heartbeat detection packet (such as a query command in a specific format) to the BMS. If a response is received from the BMS within a specified time (e.g., 0.5-1 second), it indicates that the communication link is normal, and subsequent parameter acquisition operations can proceed. If no response is received, the corresponding communication is marked as abnormal, and an attempt is made to re-establish the connection. The abnormal situation is recorded for subsequent troubleshooting and processing. After the communication link is established, the next verification and auditing steps are executed, such as identity verification (prepayment of fees) via scanning a QR code, swiping a card, or using a VIN. After initializing the communication link and establishing a communication connection with the battery BMS, charging is started. The charging system performs individual power metering for each charging terminal.

[0049] S11. Obtain the current SOC, SOH, battery voltage state parameters and limit voltage parameters of each battery at preset time intervals.

[0050] Specifically, the system sets the time interval for acquiring battery parameters based on the characteristics of the charging system and the required accuracy of battery status monitoring. For example, for fast charging scenarios, the time interval can be set to acquire parameters every 5-10 seconds; for slow charging scenarios or situations requiring higher sensitivity to changes in battery status, the time interval can be increased or decreased.

[0051] Furthermore, the charging control system sends a request command specifically for obtaining battery status parameters to each vehicle's BMS according to the adapted communication protocol. These battery status parameters include one or more of the following:

[0052] 1) Basic status indicators

[0053] SOC (State of Charge): The current remaining battery charge percentage (%);

[0054] SOH (State of Health): Battery health status (%);

[0055] SOE (State of Energy): Remaining available energy (kWh);

[0056] SOP (State of Power): Current output power (kW);

[0057] 2) Voltage, current, and temperature related parameters

[0058] Total voltage (Pack Voltage), Cell voltages, Maximum cell voltage (Max Cell Voltage), Minimum cell voltage (Min Cell Voltage);

[0059] Charging current, discharging current, and current ripple;

[0060] Maximum cell temperature, minimum cell temperature, average temperature of the battery pack, and coolant inlet / outlet temperature.

[0061] Safety limit parameters

[0062] Maximum charging voltage, minimum discharging voltage, maximum charging current, upper temperature limit, lower temperature limit, etc.

[0063] S12. Determine the target battery and the corresponding target charging terminal whose SOC is greater than a preset first threshold for each constant current charging.

[0064] Specifically, based on the charging characteristics of lithium batteries, the rate of voltage change (dV / dSOC) is relatively small at low SOC but significantly increases at high SOC. Therefore, predicting the aforementioned time information at low SOC may be inaccurate because the voltage rises slowly, and even small measurement errors can lead to large prediction time deviations. Generally, the polarization voltage changes complexly between 0-70% SOC, and the first derivative of voltage with respect to SOC varies greatly, resulting in large calculation errors and wasted computational resources. However, when the SOC exceeds a preset threshold, the battery polarization reaction tends to stabilize, which can reduce errors. Moreover, when the battery is at low SOC, its ability to accept current is strong, and this stage should be fully utilized to charge as much as possible. At this time, if power redistribution is performed in anticipation of entering the CV stage, power may be reduced prematurely, which may affect charging efficiency and lead to large prediction calculation errors. Conversely, in the high SOC region, the battery's current carrying capacity is close to saturation, and power redistribution will not significantly affect the charging speed.

[0065] Therefore, the solution in this application identifies batteries whose SOC is greater than a preset first threshold (e.g., 75%-80%) corresponding to constant current charging as target batteries, predicts and calculates the time information for their switching from the current charging state to the constant voltage charging state, and executes the corresponding control to improve the efficiency and calculation accuracy of the system.

[0066] S13. Calculate the target time for each target battery to switch to constant voltage charging, and group the target charging terminals based on each target time.

[0067] According to electrochemical principles, the terminal voltage of a battery during constant current charging can be decomposed into: , where V ocv The open-circuit voltage is related to the state of charge (SOC) by a nonlinear function, where Icc is the constant current voltage, and R is the open-circuit voltage. s Where Icc is the internal resistance, Rs is the ohmic voltage drop, and V is the internal resistance. d Let be the polarization voltage, satisfying the first-order kinetic equation. During constant-current charging, when the state of charge (SOC) exceeds a preset threshold, the internal resistance changes little in a short time, while the polarization voltage changes over time as follows: Therefore, based on the differential equation, we can derive:

[0068]

[0069] During constant current charging, dSOC / dt = I / C (battery capacity is constant). When SOC exceeds a preset threshold (e.g., when SOC > 80%), the increase in dVocv / dSOC is mainly due to ke. −at The term is dominant, and the polarization term e is also dominant. −t / μSince the time constant μ is fixed and decays to a secondary position, the voltage change rate during the constant current stage is mainly dominated by the exponential decay term, that is, it mainly follows the exponential decay law. Based on this, a corresponding exponential model can be established:

[0070]

[0071] Where k0 is the rate of change of voltage at the current time t0, that is... Where α is the attenuation coefficient and λ is the adjustment coefficient. Integrating the rate of change to obtain the voltage difference, we can get:

[0072]

[0073] Then the time parameter t can be obtained. s : .

[0074] Battery aging can affect the effective voltage difference ΔV eff =ΔV⋅(1−η(1−SOH)), meaning that the aging battery will enter the constant voltage stage earlier. Therefore, based on the current SOH, further corrections can be made to obtain:

[0075]

[0076] Preferably, considering the potential communication delays and charging terminal sampling delays in the split-type charging system, the present application further corrects the aforementioned time information using delay compensation parameters. Therefore, the corrected switching time information ts from the current charging state to the constant voltage stage, determined based on the current battery SOH, battery voltage, and limiting voltage parameters, can be expressed as:

[0077]

[0078] Where k0 is the voltage change rate at the current time t0, α, λ, and η are the corresponding adjustment coefficients, and V c V0 and V0 represent the limit voltage and the current voltage, respectively. τ is a preset communication safety parameter, which can be determined based on historical data or updated periodically based on the recorded data of each charging terminal.

[0079] Further preferably, in one embodiment of this application, after calculating the target time for each target battery to switch to constant voltage charging, the target charging terminals are grouped based on each target time. For example, based on a preset time threshold parameter, the target charging terminals are divided into two or more groups. In one embodiment, according to the time threshold, the target terminals are divided into a first target terminal with more urgent switching control and a second target terminal with relatively ample time. Furthermore, the solution of this application establishes dedicated grouping record information in the charging control system. For each group, detailed records are kept of the number of each target charging terminal within the group and the corresponding target time, etc. This facilitates subsequent targeted adjustments to charging strategies, charging monitoring, and other management operations for each target charging terminal based on the characteristics of different groups, thereby achieving more efficient and refined charging process control.

[0080] S14. If the target time is less than or equal to a preset time threshold, control the corresponding first target charging terminal to charge the corresponding battery with a second current, wherein the second current is less than the current constant current charging current.

[0081] Specifically, the charging control system compares the calculated target time for each charging terminal with a preset time threshold. If the target time is less than or equal to the preset time threshold, it indicates that the battery is about to enter the constant voltage charging stage. At this time, the control system generates corresponding control commands to take appropriate measures to smoothly transition the charging process and avoid abnormal situations such as overcharging or excessively rapid temperature rise. Specifically, the charging control system sends a control command to the corresponding first target charging terminal. The command clearly includes the specific value or functional relationship of the second current to be adjusted, as well as the relevant charging parameter adjustment requirements. After receiving the command, the first target charging terminal adjusts its internal power regulation module according to the command requirements, so that it charges the corresponding battery according to the set second current value. At the same time, it feeds back the current actual charging current, voltage, and battery status to the charging control system in real time, so that the charging control system can continue to monitor and adjust the charging process.

[0082] Preferably, in one embodiment of this application, the second charging current I satisfies:

[0083]

[0084] Among them, I cc Here, t represents the constant current charging current, β represents the corresponding time parameter, and β represents the adjustment coefficient. For example... Figure 2 The diagram shown is a schematic of the charging voltage and charging current control curves according to the above scheme in one embodiment. The actual output charging voltage / current of the charging terminal may fluctuate due to differences in the internal circuit modules.

[0085] The above-described embodiments of this application group target batteries according to the time remaining before switching to constant-voltage charging. Charging terminals with target times less than or equal to a preset time threshold gradually charge their corresponding batteries with a smaller second current, thereby ensuring a smooth transition during charging and safe charging of the batteries. This solution avoids the rigidity of traditional BMS-based fixed control strategies, effectively preventing drastic fluctuations in charging module output power caused by sudden drops in instantaneous charging power at each switching charging terminal, and potential system oscillations. Timely and effective power utilization ensures highly stable total output power and maximizes module utilization. Simultaneously, it makes the voltage rise of the charging battery more gradual when switching, reducing the urgency of forced BMS intervention (and potentially even avoiding triggering limit protection). It also effectively prevents the battery temperature from rising too quickly near the constant-voltage stage.

[0086] More preferably, in one embodiment, the method of this application further includes:

[0087] S15. If the time information is greater than a preset time threshold, a monitoring instruction is sent to the corresponding charging terminal at a preset time interval.

[0088] S16. Detect whether the corresponding communication feedback information is received within a preset time. If the feedback information is not received within the preset time after multiple consecutive detections, control the corresponding second target charging terminal to charge the corresponding battery with the second current.

[0089] The above-described embodiments of this application control the second target terminal to continue charging according to the original preset method and initiate monitoring of the second target charging terminal. After sending the monitoring command, a timing mechanism is activated to check whether the corresponding charging terminal has received communication feedback information within a preset time (e.g., set to 1-5 seconds). By monitoring the data reception of the communication link, it is determined whether a feedback data packet containing complete key status information in accordance with the communication protocol format has been received. If the corresponding feedback information is received within the preset time, it indicates that the communication is normal. The charging control system will parse and store the feedback information and further analyze and determine whether the charging status is normal based on this information. If normal, charging continues according to the original charging method. If no feedback information is received within the preset time and this continues multiple times, it can be determined that the communication or response of the corresponding second target charging terminal is abnormal, and corresponding measures need to be taken to ensure charging safety. In this case, this application controls the corresponding second target charging terminal to charge the corresponding battery with a second current in advance, and adjusts the charging current in time to ensure the safety and stability of the charging process and avoid charging risks caused by communication problems.

[0090] Furthermore, the above method also includes: if the feedback time of the corresponding second target terminal exceeds the corresponding target time, then control to stop charging the corresponding second target charging terminal.

[0091] Specifically, given that the battery is nearly fully charged, if the feedback time of the corresponding second target terminal exceeds the corresponding target time, it indicates that there may be a significant anomaly. In this case, the charging stop operation is executed first. Before executing the stop operation, a preset time (such as 0.1-0.5 seconds) will be waited for to try to obtain the charging module status again. If there is still no response, the power supply of the corresponding charging module to the charging gun will be cut off to prevent subsequent overcharging or loss of control, and a response anomaly information will be generated. After the communication or response returns to normal, the charging of the corresponding terminal will continue to be controlled according to the obtained information.

[0092] Furthermore, in one embodiment, the method described above in this application further includes:

[0093] Record the communication delay time of each charging terminal;

[0094] Based on the communication delay time, the communication security parameters of each charging terminal are corrected according to a preset period, and the corresponding parameters are updated and corrected in a timely manner to improve control accuracy.

[0095] Furthermore, in one embodiment, the method described above in this application further includes:

[0096] Determine the changes in power demand for each port within a future preset time window. If the changes are greater than a preset value, control the corresponding charging power module.

[0097] Specifically, in one embodiment of this application, the current power demand of each port is monitored in real time, and the power demand within a future time window is predicted. The change in power demand of each port within the future time window is calculated. For example, the difference between the power demand in the future time window and the current power demand is calculated, or the maximum change in power demand within the entire time window is calculated. The obtained change is compared with a preset threshold. When the change is greater than the preset value, the corresponding charging power module is controlled. For example, if the power demand increases significantly, the output power is increased; if it decreases significantly, the output power is reduced.

[0098] In one embodiment, such as Figure 3 The diagram shown is a structural block diagram of a split-type DC charging system provided in this application (details of some functional modules are not shown). The system includes a charging control subsystem, multiple charging power modules, and multiple charging terminals. These components are connected via a reliable communication network and work together to achieve DC charging for electric vehicles and other devices. The entire system can obtain electrical energy from an external AC power source (usually from the power grid) and, through reasonable allocation and control, safely and efficiently deliver DC power to the battery of the vehicle being charged. Wherein:

[0099] The charging control subsystem includes a main control unit, which uses a high-performance industrial control computer or a dedicated embedded controller. It has powerful data processing and multi-tasking capabilities and is the core of the entire charging control subsystem for operation and control. It is responsible for running various control algorithms, processing communication data, and coordinating the work of various modules.

[0100] The charging power module includes a power conversion unit and a power regulation circuit. The power conversion unit mainly consists of an AC-DC converter, which converts the input AC power (generally three-phase AC) into DC power that meets charging requirements. It has a wide range of voltage and current regulation capabilities and can output DC power at different power levels according to the instructions of the charging control subsystem. The conversion efficiency is typically high to reduce energy loss. The power regulation circuit uses advanced power electronic control technology (such as PWM control circuits) to precisely adjust the voltage and current of the output DC power according to the received control commands, achieving flexible control of the output power to meet the charging needs of different charging stages and different vehicle batteries. In addition, the charging power module also includes functional units such as a status monitoring circuit, protection circuit, charging terminal, and cooling system. Their specific working methods and principles are not detailed here.

[0101] The charging terminal includes a charging gun, a control circuit, and a DC-DC conversion module. The charging gun at the front end of the terminal is designed to comply with relevant charging standards (such as national standards and European standards), and features plugs of various sizes to accommodate the charging interfaces of various vehicle types. Internally, the charging gun contains conductive contacts and signal transmission lines to ensure the normal transmission of electrical energy and communication signals. The connection component securely connects the charging gun to the main body of the charging terminal, and also provides mechanical protection, waterproofing, and dustproofing to ensure the safety and reliability of the charging interface. The charging control circuit receives charging commands from the charging control subsystem and further adjusts and controls the DC power obtained from the charging power module according to the command requirements. It precisely controls parameters such as charging current and voltage to meet the charging needs of the vehicle battery. Simultaneously, it monitors the actual current and voltage during the charging process in real time and feeds this information back to the charging control subsystem. The DC-DC converter module further converts and regulates the DC power input from the charging power module, enabling it to better match the voltage and current requirements of different charging stages and battery types in the vehicle. This function is achieved using power electronic conversion technology, with common conversion topologies including buck, boost, and buck-boost. In addition, the charging terminal also includes communication interfaces and safety protection units; their specific operating methods and principles will not be elaborated here.

[0102] Furthermore, the charging control subsystem includes a control module to control the execution of the following steps:

[0103] Establish communication connections between each charging terminal and its corresponding battery, and control the charging terminal to charge the corresponding battery.

[0104] The current SOC, SOH, battery voltage state parameters, and limit voltage parameters of each battery are obtained at preset time intervals.

[0105] Identify the target batteries and corresponding target charging terminals whose SOC is greater than a preset first threshold for each constant current charging;

[0106] Calculate the target time for each target battery to switch to constant voltage charging, and group the target charging terminals based on each target time;

[0107] If the target time is less than or equal to a preset time threshold, the corresponding first target charging terminal is controlled to charge the corresponding battery with a second current, wherein the second current is less than the current constant current charging current.

[0108] In one embodiment, such as Figure 4 As shown, this application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the following steps:

[0109] Establish communication connections between each charging terminal and its corresponding battery, and control the charging terminal to charge the corresponding battery.

[0110] The current SOC, SOH, battery voltage state parameters, and limit voltage parameters of each battery are obtained at preset time intervals.

[0111] Identify the target batteries and corresponding target charging terminals whose SOC is greater than a preset first threshold for each constant current charging;

[0112] Calculate the target time for each target battery to switch to constant voltage charging, and group the target charging terminals based on each target time;

[0113] If the target time is less than or equal to a preset time threshold, the corresponding first target charging terminal is controlled to charge the corresponding battery with a second current, wherein the second current is less than the current constant current charging current.

[0114] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments described above. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM), etc.

[0115] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0116] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A split-type DC charging control method, characterized in that, The method includes: Establish communication connections between each charging terminal and its corresponding battery, and control the charging terminal to charge the corresponding battery. The current SOC, SOH, battery voltage state parameters, and limit voltage parameters of each battery are obtained at preset time intervals. Identify the target batteries and corresponding target charging terminals for each constant current charging cycle whose state of charge (SOC) is greater than a preset first threshold, wherein the first threshold is 75%-80%; Calculate the target time for each target battery to switch to constant voltage charging, and group the target charging terminals based on each target time. According to the time threshold, the target charging terminals are divided into a first target charging terminal with more urgent needs and a second target charging terminal with relatively ample time. A first target charging terminal with a control target time less than or equal to the time threshold charges the corresponding battery with a second current; The method further includes: The switching time information from the current charging state to the constant voltage charging state is determined based on the current battery SOH, battery voltage, and limit voltage parameters. The target time is obtained by correcting the switching time information based on the delay compensation parameters; The method further includes: At preset time intervals, a monitoring command is sent to the second target charging terminal whose target time is greater than the time threshold. If the corresponding communication feedback information is received within a preset time, then the corresponding second target charging terminal is controlled to charge the corresponding battery with the second current. If feedback is received within the preset time, determine whether the charging status is normal based on the feedback. If normal, continue charging in the original charging method. The second current is less than the current constant current charging current and gradually decreases.

2. The method according to claim 1, characterized in that, The method further includes: If the feedback time of the corresponding second target charging terminal exceeds the corresponding target time, the control will stop charging the corresponding second target charging terminal.

3. The method according to claim 1, characterized in that, The method further includes: Record the communication delay time of each charging terminal; Based on the communication delay time, the communication security parameters of each charging terminal are adjusted according to a preset period.

4. The method according to any one of claims 1-3, characterized in that, The method further includes: Determine the changes in power demand at each port within a future preset time window; If the change is greater than a preset value, the corresponding charging power module is controlled.

5. A split-type DC charging system, characterized in that, The system includes a charging control subsystem, multiple charging power modules, and multiple charging terminals. The charging control subsystem includes a control module to control the execution of the steps of the method as described in any one of claims 1 to 4.

6. A computer-readable storage medium storing a computer program that, when executed by a processor, causes the processor to perform the steps of the method as claimed in any one of claims 1 to 4.

7. A split-type DC charging control device, comprising a memory and a processor, wherein the memory stores a computer program, and when executed by the processor, the computer program causes the processor to perform the steps of the method as described in any one of claims 1 to 4.

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