Split type direct current charging system and control method

Abstract

The invention relates to the technical field of intelligent control, in particular to a split type direct current charging system and a control method. According to the scheme, the current SOC, SOH, battery voltage state parameter and limit voltage parameter of each battery are obtained, then the target batteries with the battery SOC larger than the preset first threshold value corresponding to constant-current charging and the corresponding target charging terminals are determined, and grouping is carried out according to the target time of switching to constant-voltage charging according to the distance of each target battery; and gradually charging the corresponding battery with a smaller second current by the charging terminal of which the target time is less than or equal to the preset time threshold. According to the scheme, the severe fluctuation of the output power of the charging module caused by the instantaneous charging power dropping of each switching charging terminal can be effectively avoided. And the power utilization is effectively released in time, so that the total output power is highly stable, and the module utilization rate is improved. Meanwhile, when the rechargeable battery is switched, the voltage rises more gently, and the problem that the temperature of the battery rises too fast at the stage close to the constant voltage can be effectively prevented.

Description

Technical Field

[0001] The present application relates to the field of intelligent control technology, and in particular to a split-type DC charging system and a control method. Background Art

[0002] With the rapid development of new energy vehicles, electric vehicles are experiencing a rapid growth. As a key supporting technology for electric vehicles, the performance of the charging system directly affects the ease of use, charging efficiency, and battery life of electric vehicles. The charging process for electric vehicle batteries can be roughly divided into four stages: trickle charging, constant current charging, constant voltage charging, and trickle float charging. In the constant current stage, the battery is charged with a higher current. When the battery voltage reaches a predetermined voltage, the battery management system (BMS) communicates with the charging system to enter constant voltage charging mode. At the moment of switching, the charging current decreases from a higher value to a lower value, and then gradually decreases as charging continues until the battery is fully charged.

[0003] Currently, charging systems mainly include two categories: split type and integrated type. The traditional constant current-constant voltage switching relies on the real-time instructions of the BMS. However, for a split charging system, if the switching is performed according to the real-time instructions of the BMS, it may face multiple times of violent fluctuations in the output power of the charging module caused by the instantaneous drop in current switching, which may cause system oscillation. At the same time, the battery terminal voltage changes have inertia, especially the internal resistance of aging batteries increases. In addition, the split system may have communication delays and sampling delays, which will lead to response lags and may cause charging overvoltage. In addition, when the battery charging approaches the constant voltage stage, the internal resistance of the battery will also increase. If high current charging is continued, according to Joule's law, the large current will generate a lot of heat on the internal resistance of the battery, which may help the battery heat up too quickly.

[0004] Patent document CN117621896B discloses a method for detecting DC charging anomalies. During the constant current and constant voltage charging phases, the current charging rate is used to estimate the time value T1 from the current time point to the constant current / constant voltage cutoff. The corresponding amount of electricity D1 is then compared with the theoretical Dy to determine whether charging is normal. The above scheme provides a solution for checking charging anomalies by estimating time. However, the charging rate in the constant current phase changes nonlinearly, and linear judgment based on the current charging rate will produce errors. Factors such as differences in battery aging and communication delays also have an impact. Summary of the Invention

[0005] Based on this, this application addresses the above-mentioned problems and proposes a split DC charging system and control solution, which aims to intelligently, efficiently and accurately control the split DC charging system to ensure efficient, stable and safe charging.

[0006] On one hand, the present application provides a split-type DC charging system and a control method, the method comprising: Establishing a communication connection between each charging terminal and the corresponding battery, and controlling the charging terminal to charge the corresponding battery; Obtain the current SOC, SOH, battery voltage state parameters and limit voltage parameters of each battery at preset time intervals; Determine the target battery and the corresponding target charging terminal whose SOC of the battery corresponding to each constant current charging is greater than a preset first threshold; Calculating a target time for each target battery to switch to constant voltage charging, and grouping the target charging terminals based on the target time; If the target time is less than or equal to the 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.

[0007] Furthermore, the above method further includes: if the time information is greater than a preset time threshold, sending a monitoring instruction to the corresponding charging terminal at a preset time interval; Whether the corresponding communication feedback information is received is detected within a preset time, and if not, the corresponding second target charging terminal is controlled to charge the corresponding battery with a second current.

[0008] Furthermore, the above method also includes: if the feedback time of the corresponding second target terminal exceeds the corresponding target time, controlling to stop charging the corresponding second target charging terminal.

[0009] Preferably, the determining of the time information from the current charging state to the constant voltage includes: Determine the switching time information from the current charging state to the constant voltage based on the current battery SOH, battery voltage and limit voltage parameters; The switching time information is modified based on the delay compensation parameter.

[0010] Preferably, the second current I satisfies: Among them, I cc is the constant current charging current, t is the corresponding time parameter, t w is the corrected switching time information, and β is the adjustment coefficient.

[0011] Furthermore, the above method also 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 corrected according to a preset period.

[0012] Furthermore, the method further comprises: Determine the power demand changes of each port within a preset time window in the future; If the change is greater than a preset value, the corresponding charging power module is controlled.

[0013] A second aspect of the present application further provides a split-type DC charging system, which 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 any of the above methods.

[0014] The third aspect of the present application further provides a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of any of the above methods.

[0015] In a fourth aspect, the present application further provides a split-type DC charging control device, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of any one of the above methods.

[0016] In a fifth aspect, the present application provides a computer terminal device comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of any one of the above methods.

[0017] The technical solution provided in the present application obtains the current SOC, SOH, battery voltage state parameter, and limit voltage parameter of each battery at preset time intervals, thereby determining the target batteries and corresponding target charging terminals whose SOC of the corresponding batteries for constant current charging is greater than a preset first threshold. The target batteries are then grouped according to the target time from switching to constant voltage charging. Charging terminals with target times less than or equal to the preset time threshold are then gradually charged with a smaller second current to the corresponding batteries. The above-mentioned solution of the present application circumvents the rigidity of traditional fixed control strategies based on BMS instructions, effectively avoiding the sharp drop in instantaneous charging power at each switching charging terminal, which causes drastic fluctuations in the output power of the charging module. The released power is utilized in a timely and effective manner, making the total output power highly stable and maximizing module utilization. At the same time, the voltage rise is smoother when the rechargeable battery is switched, reducing the urgency of forced BMS intervention (and possibly even avoiding triggering limit protection). It can also effectively prevent the problem of battery temperature rising too quickly near the constant voltage stage.

[0018] Furthermore, the present application scheme combines target time grouping control with charging current control based on the corresponding charging terminal's communication response, effectively avoiding response lags caused by communication delays, which can lead to charging overvoltage and uncontrolled conditions. Furthermore, the present application scheme also uses the characteristics of the battery's SOH to provide a targeted estimate of the target time, setting a safer time value for aging. This allows high-resistance aging batteries to initiate smooth current reduction in advance, avoiding subsequent overvoltage charging that affects battery life. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] in: Figure 1 Flowchart of a control method for a split-type DC charging system in one embodiment; Figure 2 Schematic diagram of charging voltage and charging current control curves in one embodiment; Figure 3 This is a structural block diagram of a split-type DC charging system in one embodiment; Figure 4 FIG. 1 is a structural block diagram of a split-type DC charging system control device in an embodiment. DETAILED DESCRIPTION

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0022] The terms "include", "comprising", and "having", and any variations thereof, in the specification and claims of this application and the accompanying drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products, or apparatuses. In the claims, specification, and accompanying drawings of this application, relational terms such as "first" and "second" are used only to distinguish one entity / operation / object from another entity / operation / object, and do not necessarily require or imply any actual relationship or order between these entities / operations / objects.

[0023] References to "embodiments" herein mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase at various locations in the specification does not necessarily refer to the same embodiment, nor are independent or alternative embodiments mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0024] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0025] In one embodiment, Figure 1 The figure shows a flow chart of a split-type DC charging system control method of the present application, the method comprising: S10: Establish a communication connection between each charging terminal and the corresponding battery, and control the charging terminal to charge the corresponding battery.

[0026] Specifically, when the charging gun is plugged 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 functioning properly. A connection detection circuit within the charging gun determines whether a complete electrical circuit has been formed. If an abnormal circuit is detected, the charging terminal screen prompts the user to reconnect the charging gun to ensure a reliable physical connection.

[0027] At the same time, further check whether the pins inside the charging gun (such as the positive and negative pins used to transmit power and the CAN bus pins used for communication) are in normal contact to prevent false connections and other situations that affect subsequent communication and charging functions.

[0028] The charging terminal further identifies the vehicle and battery type, matches them through the pre-stored vehicle communication protocol library, and calls the corresponding protocol parsing module. For vehicles with unknown protocols, it starts the automatic identification program and sends a general protocol detection request to the vehicle battery management system (BMS). Based on the BMS's response, it analyzes and determines the applicable communication protocol.

[0029] Furthermore, the system sends a simple heartbeat check packet (e.g., a query command in a specific format) to the BMS. If a response is received from the BMS within a specified timeframe (e.g., 0.5-1 second), the communication link is normal and subsequent parameter acquisition operations can proceed. If no response is received, the system flags the corresponding communication anomaly and attempts to reestablish the connection. The anomaly is also recorded for subsequent investigation and resolution. Once the communication link is established, the system proceeds to the next verification and audit step, such as identity verification (prepayment) via an app, QR code scanning, card swiping, or VIN verification. The communication link is initialized, establishing a connection with the battery BMS, and charging begins. The charging system then individually measures the power consumption of each charging terminal.

[0030] S11 . Obtain the current SOC, SOH, battery voltage state parameters, and limit voltage parameters of each battery at preset time intervals.

[0031] Specifically, the system sets the 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 interval can be set to acquire parameters every 5-10 seconds; for slow charging scenarios or situations that require higher sensitivity to battery status changes, the interval can be increased or decreased.

[0032] Furthermore, the charging control system sends a request instruction specifically for obtaining battery status parameters to each vehicle BMS according to the adapted communication protocol. The battery status parameters include one or more of the following: 1) Basic status indicators SOC (State of Charge): The current remaining battery power percentage (%); SOH (State of Health): Battery health status (%); SOE (State of Energy): remaining available energy (kWh); SOP (State of Power): current output power (kW); 2) Voltage, current, and temperature related parameters Total voltage (Pack Voltage), cell voltages (Cell Voltages), maximum cell voltage (Max Cell Voltage), minimum cell voltage (Min Cell Voltage); Charging Current, Discharging Current, Current Ripple; Maximum cell temperature (Max Cell Temperature), minimum cell temperature (Min Cell Temperature), average battery pack temperature (Average Temperature), coolant inlet / outlet temperature (Coolant Inlet / Outlet Temp); Safety limit parameters Maximum charging voltage, minimum discharging voltage, maximum charging current, upper temperature limit, lower temperature limit, etc.

[0033] S12: Determine target batteries and corresponding target charging terminals whose SOCs of batteries corresponding to the constant current charging are greater than a preset first threshold.

[0034] Specifically, based on the charging characteristics of lithium batteries, the battery voltage change rate (dV / dSOC) is small at low SOC and significantly increases at high SOC. Therefore, the above-mentioned time information may be inaccurate at low SOC because the voltage rises slowly, and even small measurement errors can lead to significant deviations in the predicted time. Generally, the polarization voltage changes in the battery between 0 and 70% SOC, resulting in complex variations in the first-order derivative of the voltage with respect to SOC. This results in large calculation errors and wastes computing resources. However, when the SOC exceeds a preset threshold, the battery polarization reaction stabilizes, reducing the error. Furthermore, when the battery is at a low SOC, its current acceptance capacity is strong, and this phase should be fully utilized to maximize charging. At this time, predicting the impending CV phase and implementing power redistribution may prematurely reduce power, which in turn affects charging efficiency and leads to large prediction errors. Conversely, in the high SOC region, the battery's current handling capacity is near saturation, and power redistribution does not significantly affect charging speed.

[0035] Therefore, the present application solution determines the battery whose SOC corresponding to each constant current charging is greater than a preset first threshold (such as 75%-80%) as the target battery, and predicts and calculates the time information for switching from the current charging state to the constant voltage charging state and performs corresponding control to improve the efficiency and calculation accuracy of the system.

[0036] S13: Calculate the target time for each target battery to switch to constant voltage charging, and group the target charging terminals based on the target time.

[0037] According to electrochemical knowledge, the terminal voltage of the battery during constant current charging can be decomposed into , where V ocv is the open circuit voltage, which has a nonlinear functional relationship with SOC, Icc is the constant current voltage, R s is the internal resistance, Icc•Rs is the ohmic voltage drop, V d is the polarization voltage, which satisfies the first-order kinetic equation. During constant current charging, when the SOC is higher than the preset threshold, the internal resistance does not change much in a short period of time, and the change of polarization voltage over time can be expressed as: , therefore, based on the differential equation we can deduce: During constant current charging, dSOC / dt=I / C (battery capacity is constant). When SOC is higher than the preset threshold (e.g., when SOC>80%), the increase in dVocv / dSOC is mainly due to the increase in ke −at The term is dominant, and the polarization term e −t / μ Because the time constant μ is fixed and decays to a secondary position, the voltage change rate in the constant current stage is mainly dominated by the exponential decay term, that is, it mainly obeys the exponential decay law. Based on this, the corresponding exponential model can be established: Among them, k0 is the voltage change rate at the current time t0, that is, , α is the attenuation coefficient, and λ is the adjustment coefficient. Integrating the rate of change to find the voltage difference yields: Then we can get the time parameter t s : .

[0038] As battery aging affects the effective voltage difference ΔV eff =ΔV⋅(1−η(1−SOH)), that is, the aging battery will enter the constant voltage stage early, so further correction based on the current SOH can be obtained: Preferably, taking into account the corresponding communication delay and charging terminal sampling delay that may exist in the split charging system, the present application solution further corrects the above time information through the delay compensation parameter. Then, the corrected switching time information ts from the current charging state to the constant voltage stage is determined based on the current battery SOH, battery voltage and limit voltage parameters and can be expressed as: Among them, k0 is the voltage change rate at the current time t0, α, λ, η are the corresponding adjustment coefficients, V c , V0 are the limit voltage and current voltage respectively, τ is the preset communication safety parameter, which can be comprehensively determined based on historical data, or regularly updated and changed according to the recorded data of each charging terminal.

[0039] Further preferably, in one embodiment of the present 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 a more urgent switching control and a second target terminal with relatively ample time. Furthermore, the present application solution establishes special group recording information in the charging control system, and for each group, records in detail the key information such as the number of each target charging terminal in the group and the corresponding target time, so as to facilitate the subsequent implementation of targeted charging strategy adjustments, charging monitoring and other management operations for each target charging terminal based on the characteristics of different groups, thereby achieving more efficient and more refined charging process control.

[0040] 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.

[0041] Specifically, the charging control system will calculate the target time corresponding to each charging terminal and compare it with the preset time threshold. If the target time is less than or equal to the preset time threshold, it means that the battery is about to enter the constant voltage charging stage. At this time, the control system generates a corresponding control instruction and takes corresponding measures to smoothly transition the charging process to avoid abnormal situations such as overcharging and rapid temperature rise. Specifically, the charging control system sends a control instruction to the corresponding first target charging terminal. The instruction clearly includes the specific numerical value or functional relationship of the second current to be adjusted and the relevant charging parameter adjustment requirements. After the first target charging terminal receives the instruction, its internal power regulation module adjusts the output current according to the instruction 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, battery status and other information to the charging control system in real time, so that the charging control system can continue to perform subsequent monitoring and charging process adjustments.

[0042] Preferably, in one embodiment of the present application, the second charging current I satisfies: Among them, I cc is the constant charging current, t is the corresponding time parameter, and β is the adjustment coefficient. Figure 2 FIG. 1 is a schematic diagram of a charging voltage and charging current control curve according to the above solution in one embodiment. The charging voltage / current actually output by the charging terminal may fluctuate based on differences in internal circuit modules.

[0043] The above-mentioned embodiment scheme of the present application groups each target battery according to the target time from switching to constant voltage charging, and gradually charges the corresponding battery with a smaller second current for the charging terminal whose target time is less than or equal to the preset time threshold, thereby ensuring a smooth transition of the charging process and safe charging of the battery. The above-mentioned scheme of the present application circumvents the rigidity problem of the traditional fixed control strategy based on BMS instructions, and can effectively avoid the sharp drop in the instantaneous charging power of each switched charging terminal, which causes drastic fluctuations in the output power of the charging module and possible system oscillations. And the power released in a timely and effective manner is utilized, so that the total output power is highly stable and the module utilization rate is maximized. At the same time, the voltage rise is smoother when the rechargeable battery is switched, reducing the urgency of the forced intervention of the BMS (and may even avoid triggering the limit protection). It can also effectively prevent the problem of the battery temperature rising too fast near the constant voltage stage.

[0044] Further preferably, in one embodiment, the method of the present application further comprises: 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; S16. Detect whether corresponding communication feedback information is received within a preset time. If no feedback information is received within the preset time after multiple consecutive detections, control the corresponding second target charging terminal to charge the corresponding battery with a second current.

[0045] In the above-described embodiment of the present application, the second target terminal is controlled to continue charging according to the original preset method and monitoring of the second target charging terminal is initiated. After the monitoring command is sent, a timing mechanism is activated to detect whether communication feedback information is received from the corresponding charging terminal within a preset time (e.g., set to 1-5 seconds). The timing mechanism also monitors data reception on the communication link to determine whether a feedback packet conforming to the communication protocol format and containing complete key status information has been received. If the corresponding feedback information is received within the preset time, it indicates that communication is normal. The charging control system parses and stores the feedback information and further analyzes it to determine whether the charging status is normal. If normal, charging continues according to the original charging method. If the feedback information is not received within the preset time and continues for multiple times, it can be determined that the communication or response of the corresponding second target charging terminal is abnormal, and appropriate measures need to be taken to ensure charging safety. In this case, the present application controls the corresponding second target charging terminal to charge the corresponding battery with a second current in advance, and timely adjusts the charging current to ensure the safety and stability of the charging process and avoid charging risks caused by communication problems.

[0046] Furthermore, the above method also includes: if the feedback time of the corresponding second target terminal exceeds the corresponding target time, controlling to stop charging the corresponding second target charging terminal.

[0047] Specifically, considering 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 major abnormality. At this time, the charging stop operation is executed first. Before executing the stop, it will wait for a preset time (such as 0.1-0.5 seconds) and 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 abnormality information will be generated. After the communication or response returns to normal, the corresponding terminal will continue to control charging according to the acquired information.

[0048] Furthermore, in one embodiment, the method of the present application solution 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 corrected according to a preset period, so as to timely update and correct the corresponding parameters and improve control accuracy.

[0049] Furthermore, in one embodiment, the method of the present application solution further includes: Determine the power demand change of each port within a future preset time window, and if the change is greater than a preset value, control the corresponding charging power module.

[0050] Specifically, in one embodiment of the present application, by monitoring the current power demand of each port in real time and predicting the power demand in a future time window, the change in power demand of each port in 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.

[0051] In one embodiment, Figure 3 The figure shows a structural block diagram of a split-type DC charging system provided by the present 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 functions for electric vehicles and other equipment. The entire system can obtain electrical energy from an external AC power source (usually from the power grid) and, through reasonable distribution and control, safely and efficiently transmit DC power to the battery of the vehicle to be charged. Among them: The charging control subsystem includes a main control unit, which uses a high-performance industrial control computer or a dedicated embedded controller with powerful data processing and multi-tasking capabilities. It is the core computing and control core of the entire charging control subsystem, responsible for running various control algorithms, processing communication data, and coordinating the work of various modules.

[0052] The charging power module includes a power conversion unit and a power conditioning circuit. The power conversion unit primarily consists of an AC-DC converter, which converts incoming alternating current (typically three-phase) into direct current (DC) that meets charging requirements. It features a wide range of voltage and current regulation capabilities, capable of outputting DC power at varying power levels based on instructions from the charging control subsystem. The conversion efficiency is typically high, minimizing energy loss. The power conditioning circuit utilizes advanced power electronics control technologies (such as PWM control circuits) to precisely adjust the voltage and current of the output DC power based on received control instructions, enabling flexible control of output power to meet the charging requirements of different charging stages and vehicle batteries. The charging power module also includes functional units such as a status monitoring circuit, a protection circuit charging terminal, and a heat dissipation system. The specific operating methods and principles of these units are not detailed here.

[0053] The charging terminal consists of a charging gun, control circuitry, and a DC-DC converter module. The front end of the charging terminal features a charging gun designed to comply with relevant charging standards (such as national and European standards). It features plugs of varying specifications, adapting to the charging ports of various vehicle types. Internally, the gun contains conductive contacts and signal transmission lines to ensure the proper transmission of power and communication signals. The connection assembly securely connects the gun to the main body of the charging terminal and provides mechanical protection, waterproofing, and dustproofing to ensure the safety and reliability of the charging port. The charging control circuit receives charging commands from the charging control subsystem and further regulates and controls the DC power drawn from the charging power module in accordance with these commands. It precisely controls charging parameters such as current and voltage to meet the vehicle's battery charging requirements. It also monitors the actual current and voltage during charging in real time and provides feedback to the charging control subsystem. The DC-DC converter module reconverts and regulates the DC power input from the charging power module to better match the voltage and current requirements of the vehicle battery at different charging stages and for different battery types. This function is achieved through power electronics conversion technology. Common conversion topologies include buck, boost, and buck-boost. The charging terminal also includes communication interfaces and safety protection units. The specific operating methods and principles of these units are not detailed here.

[0054] Furthermore, the charging control subsystem includes a control module to control the execution of the following steps: Establishing a communication connection between each charging terminal and the corresponding battery, and controlling the charging terminal to charge the corresponding battery; Obtain the current SOC, SOH, battery voltage state parameters and limit voltage parameters of each battery at preset time intervals; Determine the target battery and the corresponding target charging terminal whose SOC of the battery corresponding to each constant current charging is greater than a preset first threshold; Calculating a target time for each target battery to switch to constant voltage charging, and grouping the target charging terminals based on the target time; If the target time is less than or equal to the 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.

[0055] In one embodiment, Figure 4 As shown, the present application further 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: Establishing a communication connection between each charging terminal and the corresponding battery, and controlling the charging terminal to charge the corresponding battery; Obtain the current SOC, SOH, battery voltage state parameters and limit voltage parameters of each battery at preset time intervals; Determine the target battery and the corresponding target charging terminal whose SOC of the battery corresponding to each constant current charging is greater than a preset first threshold; Calculating a target time for each target battery to switch to constant voltage charging, and grouping the target charging terminals based on the target time; If the target time is less than or equal to the 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.

[0056] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The program can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database 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), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0057] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, 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.

[0058] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A split-type DC charging control method, characterized in that: The method comprises: Establishing a communication connection between each charging terminal and the corresponding battery, and controlling the charging terminal to charge the corresponding battery; Obtain the current SOC, SOH, battery voltage state parameters and limit voltage parameters of each battery at preset time intervals; Determine the target battery and the corresponding target charging terminal whose SOC of the battery corresponding to each constant current charging is greater than a preset first threshold; Calculating a target time for each target battery to switch to constant voltage charging, and grouping the target charging terminals based on the target time; If the target time is less than or equal to the 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.

2. The method according to claim 1, characterized in that The method further comprises: 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; Whether the corresponding communication feedback information is received is detected within a preset time, and if not, the corresponding second target charging terminal is controlled to charge the corresponding battery with a second current.

3. The method according to claim 2, characterized in that The method further comprises: If the feedback time of the corresponding second target terminal exceeds the corresponding target time, the control stops charging the corresponding second target charging terminal.

4. The method according to claim 1, wherein Said also includes: Determine the switching time information from the current charging state to the constant voltage based on the current battery SOH, battery voltage and limit voltage parameters; The switching time information is modified based on the delay compensation parameter.

5. The method according to claim 4, characterized in that The second current I satisfies: Among them, I cc is the constant current charging current, t is the corresponding time parameter, t w is the corrected switching time information, and β is the adjustment coefficient.

6. The method according to claim 4, characterized in that The method further comprises: Record the communication delay time of each charging terminal; Based on the communication delay time, the communication security parameters of each charging terminal are corrected according to a preset period.

7. The method according to any one of claims 1 to 6, characterized in that The method further comprises: Determine the power demand changes of each port within a preset time window in the future; If the change is greater than a preset value, the corresponding charging power module is controlled.

8. 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 according to any one of claims 1 to 7.

9. A computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor is caused to perform the steps of the method according to any one of claims 1 to 7.

10. A split-type DC charging control device, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the method according to any one of claims 1 to 7.

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