Vehicle-mounted charging and discharging system and method based on V2G technology

Abstract

The invention discloses a vehicle-mounted charging and discharging system and method based on a V2G technology, and relates to the technical field of electric vehicle charging and discharging. The system comprises a power grid interaction module used for performing power grid connection confirmation, overcurrent protection, leakage protection and grid-connected synchronous detection; the man-machine interaction module is used for displaying a charging and discharging setting interface and battery state information and supporting remote operation of a user; the communication module is used for realizing information interaction with an external power grid dispatching center and a cloud management platform; the vehicle-mounted charging and discharging module is used for adjusting charging and discharging voltage and current of a vehicle power battery; the battery management module is used for collecting state parameters of a vehicle power battery and controlling and protecting the charging and discharging process. The control center module is used for monitoring battery parameters, receiving a user instruction and an external power grid dispatching signal, predicting the power of a vehicle power battery and generating a charging and discharging plan. The method can improve the flexibility and economy of the electric vehicle participating in the power grid interaction, guarantees the safety of the battery, and prolongs the service life of the battery.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric vehicle charging and discharging, and particularly relates to a vehicle-mounted charging and discharging system and method based on V2G technology. BACKGROUND

[0002] With the rapid development of the electric vehicle industry, its potential as a distributed energy storage unit to participate in grid interaction is increasingly prominent. As a key technology to realize the two-way interaction between electric vehicles and the power grid, V2G technology has become an important research direction in the field of smart grid and smart transportation. V2G technology allows electric vehicles to charge and store energy when the power grid load is low, and to discharge to the power grid when the power grid load is high, thereby playing a role in peak shaving, promoting renewable energy consumption, and improving power grid stability.

[0003] However, existing vehicle-mounted charging and discharging systems focus on one-way charging functions, have low integration of two-way charging and discharging functions, single control strategies, and insufficient intelligence; existing systems lack comprehensive consideration of user driving habits, real-time grid status, and weather factors, and cannot provide personalized charging and discharging strategies for users, making it difficult to meet the needs of grid dynamic scheduling and user diversification scenarios. In addition, the power regulation of traditional V2G systems mostly uses centralized optimization methods, which have high computational complexity and are difficult to achieve fast solution of electric vehicle power flexibility, lack of detailed consideration of battery health status, and long-term disordered charging and discharging may lead to battery life decay.

[0004] Therefore, a vehicle-mounted charging and discharging system and method based on V2G technology are proposed to solve the problems existing in the prior art, which is a problem that needs to be solved by those skilled in the art. SUMMARY

[0005] Therefore, the present application provides a vehicle-mounted charging and discharging system and method based on V2G technology, which can improve the flexibility and economy of electric vehicles participating in grid interaction, ensure battery safety, and prolong battery life.

[0006] To achieve the above purpose, the present application adopts the following technical solutions: A vehicle-mounted charging and discharging system based on V2G technology, comprising: a grid interaction module for grid connection confirmation, overcurrent protection, leakage protection, and grid synchronization detection; a human-computer interaction module that displays a charging and discharging setting interface and vehicle power battery state information through a local human-computer interaction interface of a touch display screen, and supports user remote monitoring, issuing user instructions, and receiving intelligent reminders through a mobile terminal APP; a communication module for realizing information interaction between the external grid dispatching center and the cloud management platform; The vehicle-mounted charging and discharging module is connected with the vehicle power battery and is used for adjusting the charging and discharging voltage and current of the vehicle power battery. The battery management module is connected with the vehicle-mounted charging and discharging module and the vehicle power battery and is used for collecting the state parameters of the vehicle power battery. The control center module is connected with the battery management module, the communication module, the power grid interaction module and the man-machine interaction module respectively, is used for monitoring the state parameters of the vehicle power battery in real time, controlling and protecting the charging and discharging process, receiving and controlling the execution of user instructions and external power grid scheduling signals, predicting the power of the vehicle power battery according to the real-time vehicle power battery state parameters and user behavior information, generating a charging and discharging plan and providing a decision basis for power grid scheduling.

[0007] The system can further comprise a communication module supporting one or more of 4G / 5G cellular communication, Wi-Fi, Bluetooth, LoRa or NB-IoT. The information interaction content comprises power grid scheduling instructions, real-time electricity price information, user charging and discharging preference settings, vehicle location information, battery state information and charging and discharging history data.

[0008] The vehicle-mounted charging and discharging module comprises an alternating current interface, a bidirectional AC / DC converter, a direct current bus, a bidirectional DC / DC converter and a battery interface connected in sequence. The alternating current interface is used for connecting an external alternating current power grid. The battery interface is used for connecting the vehicle power battery. The bidirectional AC / DC converter is used for bidirectional conversion between alternating current of the power grid and direct current of the battery. The bidirectional DC / DC converter is connected with the vehicle power battery and the bidirectional AC / DC conversion module and is used for adjusting the charging and discharging voltage and current.

[0009] The bidirectional AC / DC converter adopts a full-bridge topology structure, has a power factor correction function, can work in a rectification mode and an inversion mode and supports a wide range of alternating current voltage input. The bidirectional DC / DC converter adopts an isolated or non-isolated topology and is used for realizing bidirectional conversion between the direct current bus voltage and the power battery voltage and providing stable charging and discharging current.

[0010] The battery management module collects the state parameters of the vehicle power battery, which comprise battery monomer voltage, total voltage, charging and discharging current, battery temperature, state of charge SOC, state of health SOH and battery available capacity.

[0011] The control center module adopts a multi-core processor architecture and comprises a battery health monitoring unit, a multi-mode control unit and a power prediction unit. a battery health monitoring unit, which diagnoses the battery health status according to the state parameters of the vehicle power battery; a multi-mode control unit, which provides four working modes for users to freely switch, including: an intelligent mode: automatically generating an optimal charging and discharging strategy according to historical vehicle use data, real-time power grid information and weather conditions; a custom mode: users manually set the charging and discharging time period and power parameters; a platform hosting mode: the charging and discharging strategy is uniformly scheduled by the cloud platform according to the power grid demand; an emergency backup mode: providing emergency power supply for important loads in the case of power grid failure or natural disasters; a power prediction unit, which constructs a vehicle power battery power prediction model based on a neural network; constructs a training sample set by collecting historical V2G data, including: charging time, discharging time, charging and discharging power, battery SOC change and user vehicle use time; trains the vehicle power battery power prediction model using the training sample set to obtain the trained vehicle power battery power prediction model; quickly predicts the vehicle power battery power according to the real-time input vehicle power battery state parameters and user behavior information, and provides decision basis for power grid scheduling.

[0012] A vehicle-mounted charging and discharging method based on V2G technology, applied to the vehicle-mounted charging and discharging system based on V2G technology described in any one of the above, comprising: S1, after the vehicle is connected to the external power grid, the power grid interaction module performs connection safety detection, including overvoltage, undervoltage, overcurrent, leakage and ground detection; after the detection is passed, the communication module establishes communication connection with the power grid dispatching center and the cloud management platform; S2, determine the user's charging and discharging control information through the human-computer interaction module, including: the current working mode of the electric vehicle, the charging and discharging setting information corresponding to the current working mode and the identity information of the electric vehicle user, and call the personalized settings; S3, obtain the real-time electricity price, power grid load state, dispatching demand signal and user instruction through the communication module; S4, obtain the current SOC, SOH, temperature and health parameters of the power battery through the battery management module, and obtain the current state of the vehicle; S5, select and set the working mode through the control center module, generate the charging and discharging plan, including: charging and discharging start / end time and target SOC; S6, according to the charging and discharging plan, send control instructions to the vehicle-mounted charging and discharging module, control the working mode and power of the bidirectional AC / DC converter and bidirectional DC / DC converter; S7, when reaching the end time of the charging and discharging plan, the target SOC or receiving a termination instruction, the control vehicle-mounted charging and discharging module stops working, disconnects the connection with the power grid; the communication module uploads the charging and discharging data to the cloud management platform for electricity bill / subsidy settlement, and feeds back the result to the user mobile terminal APP.

[0013] The above method, optionally, in the charging and discharging process, the power battery state parameters and the power grid state are monitored in real time, if the battery over-temperature, over-voltage, over-current or power grid failure occurs, the protection mechanism is triggered to interrupt the charging and discharging; if the power grid dispatching instruction update or user instruction change is received, the charging and discharging power is dynamically adjusted or the charging and discharging is terminated.

[0014] According to the above technical solution, compared with the prior art, the application provides a vehicle-mounted charging and discharging system and method based on V2G technology, which has the following beneficial effects: The application realizes the bidirectional flow of energy between the vehicle and the power grid by integrating bidirectional AC / DC and DC / DC converters, meets the charging demand of the vehicle, and can feedback power to the power grid to participate in peak shaving; multi-objective optimization is carried out in combination with power grid dispatching, electricity price signals, user demand and battery state to realize the balance of maximum income, timely response of the power grid and prioritization of battery protection; four working modes (intelligent mode, custom mode, platform hosting mode and emergency backup mode) are proposed to meet the user demand in different scenarios; the power flexibility of the electric vehicle can be quickly solved by analyzing the historical V2G data through the neural network, overcoming the shortcomings of high computational complexity and slow response speed of traditional centralized optimization algorithms; real-time monitoring and participation in charging and discharging control are realized through over-voltage, over-current and over-temperature protection and SOC / SOH limitation to avoid battery damage and prolong the service life; various communication protocols and power grid standards are supported, which can adapt to different brands of charging piles and power grid dispatching systems, and is convenient for large-scale popularization and application. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are only embodiments of the application, and those skilled in the art can obtain other drawings according to the provided drawings without creative labor.

[0016] Figure 1 A structure diagram of a vehicle-mounted charging and discharging system based on V2G technology provided by the application; Figure 2 A flowchart of a vehicle-mounted charging and discharging method based on V2G technology provided by the application. DETAILED DESCRIPTION

[0017] Clearly, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0018] In the present application, the relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations, the term "include", "contain" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment. Without more limitation, the element defined by the sentence "including a…" does not exclude the presence of another same element in the process, method, article or equipment including the element.

[0019] Referring to Figure 1 As shown in the figure, the present application discloses a vehicle-mounted charging and discharging system based on V2G technology, comprising: A power grid interaction module for power grid connection confirmation, overcurrent protection, leakage protection and grid synchronization detection; A man-machine interaction module, through the local man-machine interaction interface of the touch display screen, displays the charging and discharging setting interface and the vehicle power battery state information, through the mobile terminal APP, supports user remote monitoring, issuing user instructions and receiving intelligent reminders; A communication module for realizing information interaction between the external power grid dispatching center and the cloud management platform; A vehicle-mounted charging and discharging module connected with the vehicle power battery for adjusting the charging and discharging voltage and current of the vehicle power battery; A battery management module connected with the vehicle-mounted charging and discharging module and the vehicle power battery for collecting the state parameters of the vehicle power battery; A control center module connected with the battery management module, the communication module, the power grid interaction module and the man-machine interaction module for real-time monitoring of the state parameters of the vehicle power battery, controlling and protecting the charging and discharging process, receiving and controlling the execution of user instructions and external power grid dispatching signals, predicting the power of the vehicle power battery according to the real-time vehicle power battery state parameters and user behavior information, generating a charging and discharging plan and providing a decision basis for power grid dispatching.

[0020] Further, the human-computer interaction module displays a charging and discharging setting interface and vehicle power battery state information through a local human-computer interaction interface of the touch display screen, supports remote monitoring and control, receives intelligent reminders, user identity authentication and personalized settings through a mobile terminal APP, and needs to obtain explicit authorization of the user through the user terminal APP or the vehicle touch display screen before V2G discharging operation, and performs two-way identity authentication and data encryption transmission with the power grid dispatching center to ensure the safety of the power grid and the rights and interests of the user.

[0021] Further, the communication module supports one or several of 4G / 5G cellular communication, Wi-Fi, Bluetooth, LoRa or NB-IoT. The content of information interaction includes power grid dispatching instructions (including charging and discharging power, time period requirements), real-time electricity price information, user charging and discharging preference settings, vehicle location information, battery state information and charging and discharging history data. Further, the vehicle-mounted charging and discharging module includes an alternating current interface, a bidirectional AC / DC converter, a direct current bus, a bidirectional DC / DC converter and a battery interface connected in sequence. The alternating current interface is used to connect an external alternating current power grid. The battery interface is used to connect a vehicle power battery. The alternating current interface and the battery interface conform to the international standard charging connection interface. The bidirectional AC / DC converter is used for bidirectional conversion between power grid alternating current and battery direct current. The bidirectional DC / DC converter connects the vehicle power battery and the bidirectional AC / DC conversion module, and is used for adjusting charging and discharging voltage and current.

[0022] Further, the bidirectional AC / DC converter adopts a full-bridge topology structure, has a power factor correction (PFC) function, can work in a rectification mode (charging) and an inversion mode (discharging), and supports wide-range alternating current voltage input. The bidirectional DC / DC converter adopts an isolated or non-isolated topology, is used for realizing bidirectional conversion between direct current bus voltage and power battery voltage, and provides stable charging and discharging current.

[0023] Further, the battery management module collects state parameters of the vehicle power battery, including battery monomer voltage, total voltage, charging and discharging current, battery temperature, state of charge SOC, state of health SOH and battery available capacity.

[0024] Further, the control center module adopts a multi-core processor architecture, including a battery health monitoring unit, a multi-mode control unit and a power prediction unit. The battery health monitoring unit diagnoses the battery health state according to the state parameters of the vehicle power battery. Multi-mode control unit, providing four working modes for users to freely switch, including: Intelligent mode: automatically generating optimal charging and discharging strategies based on historical vehicle use data, real-time power grid information, and weather conditions; Specifically including: obtaining users' historical vehicle use data, including daily driving distance, departure time, return time, etc.; Obtaining real-time power grid information, including power grid load, electricity price signal, peak shaving demand, etc.; Obtain the weather and special time period of the day; Obtain battery health status information, including the voltage, capacity and health status of each single battery; The system generates personalized charging and discharging strategies based on this information; For example, when predicting that the user has a long trip the next day, the system will prioritize ensuring sufficient battery power; When the electricity price is low and the power grid load is low, the system will automatically charge; When the electricity price is high and the power grid load is heavy, the system will appropriately discharge to obtain economic benefits and support stable operation of the power grid; Custom mode: users manually set charging and discharging time periods and power parameters, and the system will execute charging and discharging control according to the user's set parameters, and provide optimization suggestions in the process; When the user's charging and discharging strategy conflicts with the power grid peak shaving demand, the system will prompt the user to adjust the strategy to obtain better economic benefits; Platform hosting mode: charging and discharging strategies are uniformly scheduled by the cloud platform according to power grid demand; The charging platform will automatically predict the power grid charging and discharging load control curve information every day, and according to the user's input of the vehicle pickup time, the minimum SOC for discharging, and the maximum SOC for charging, it will automatically generate charging and discharging load control curve information for the vehicle; When the power load and / or transformer capacity changes, the charging platform will generate new charging and discharging load control curve information and issue it to the charging pile, and the charging pile will execute charging and discharging control according to the latest received charging and discharging load control curve information; Emergency backup mode: providing emergency power supply for important loads in the event of power grid failure or natural disasters; The system will prioritize ensuring that the vehicle battery has sufficient power to provide emergency power supply for important loads in the event of power grid failure or natural disasters; In this mode, the system will not respond to the power grid's request for discharging unless the user manually allows it; The power prediction unit constructs a vehicle power battery power prediction model based on a neural network; a training sample set is constructed by collecting historical V2G data, including charging time, discharging time, charging and discharging power, battery SOC change and user vehicle use time; the vehicle power battery power prediction model is trained using the training sample set to obtain a trained vehicle power battery power prediction model; the vehicle power battery power is quickly predicted according to real-time input vehicle power battery state parameters and user behavior information, providing a decision basis for power grid dispatching; the system can obtain real-time battery SOC data of the electric vehicle and update the power prediction in real time, realize dynamic regulation and control of the V2G power of the electric vehicle, adapt to dynamic changes of the battery state, and ensure real-time and accuracy of the charging and discharging strategy.

[0025] A vehicle-mounted charging and discharging method based on V2G technology is applied to the vehicle-mounted charging and discharging system based on V2G technology in any of the above aspects, comprising: S1, after the vehicle accesses the external power grid, the power grid interaction module performs connection safety detection, including overvoltage, undervoltage, overcurrent, leakage and grounding detection; after the detection is passed, the communication module establishes a communication connection with the power grid dispatching center and the cloud management platform; S2, determine the user's charging and discharging control information through the man-machine interaction module, including: the current working mode of the electric vehicle, the charging and discharging setting information corresponding to the current working mode and the identity information of the electric vehicle user, and call the personalized setting; S3, obtain the real-time electricity price, power grid load state, dispatching demand signal and user instruction through the communication module; S4, obtain the current SOC, SOH, temperature and health parameters of the power battery through the battery management module, and obtain the current state of the vehicle; S5, select and set the working mode through the control center module, generate the charging and discharging plan, including: the charging and discharging start / end time and the target SOC; S6, according to the charging and discharging plan, send control instructions to the vehicle-mounted charging and discharging module, control the working mode and power of the bidirectional AC / DC converter and the bidirectional DC / DC converter; S7, when the charging and discharging plan end time, the target SOC or the termination instruction is received, the vehicle-mounted charging and discharging module stops working and disconnects with the power grid; the communication module uploads the charging and discharging data to the cloud management platform for electricity fee / subsidy settlement, and feeds back the result to the user mobile terminal APP.

[0026] Further, in the charging and discharging process, the power battery state parameters and the power grid state are monitored in real time; if the battery overtemperature, overvoltage, overcurrent or power grid failure occurs, the protection mechanism is triggered to interrupt the charging and discharging; if the power grid dispatching instruction update or the user instruction change is received, the charging and discharging power is dynamically adjusted or the charging and discharging is terminated; Further, overvoltage protection: when the voltage of a single cell or the total voltage exceeds the set threshold, reduce the charging and discharging power or stop charging and discharging; Overcurrent protection: when the charging and discharging current exceeds the safety threshold set by the battery management system, immediately cut off the charging and discharging circuit; Over-temperature protection: stop charging and discharging when the battery temperature exceeds the upper threshold (such as 55°C), and reduce the charging current or start the heating device when the temperature is below the lower threshold (such as 0°C); Power grid failure protection: when detecting abnormal grid voltage, frequency exceeding the allowed range or island effect, immediately stop inverter discharging and disconnect from the grid.

[0027] In one embodiment, the communication module: integrates 4G Cat.1 module and Wi-Fi module, supports communication with cloud management platform (Aliyun IoT) and power grid dispatching center (through OCPP protocol), data transmission rate ≥1Mbps, delay ≤100ms; Power grid interaction module: integrated at the AC charging interface, including overcurrent protector (32A), leakage protector (action current ≤30mA), relay and grid synchronization detection circuit (detecting voltage, frequency, phase difference); Vehicle-mounted charging and discharging module: full-bridge IGBT topology is used for bidirectional AC / DC converter, input voltage range AC 100V-240V (50 / 60Hz), maximum output power 11kW; isolated LLC resonant topology is used for bidirectional DC / DC converter, input voltage range DC 300V-450V, output voltage range DC 200V-400V, supporting maximum charging and discharging current 50A; Battery management module: adopts distributed acquisition scheme, monitors 16 strings of power battery single cell voltage (accuracy ±5mV), total voltage (accuracy ±0.5%), charging and discharging current (accuracy ±1%), configures 6 temperature sensors (NTC) to monitor battery pack temperature (range -40℃~85℃, accuracy ±1℃), and calculates SOC (accuracy ±3%) and SOH in real time; The user connects the vehicle to the household charging pile or public V2G charging pile, and the power grid interaction module first performs 100ms insulation detection (insulation resistance >500Ω / V), then detects the grid voltage (AC 220V±10%) and frequency (50Hz±2Hz), and confirms that there is no error. The main relay is closed, the communication module connects the cloud platform through the 4G network, and completes identity authentication (based on SIM card IMSI and device serial number); The cloud platform issues the current grid peak-valley electricity price (such as peak period 18:00-22:00, electricity price 1.2 yuan / kWh; low valley period 0:00-6:00, electricity price 0.3 yuan / kWh) and grid load warning signal (current load rate 85%, encourage discharging); BMS uploads current SOC=80%, SOH=95%, battery temperature 25℃, available discharging capacity 50kWh; user sets departure time as next day 8:00 through APP, target SOC≥70%, minimum reserved SOC=20%; The cloud management platform uses dynamic programming algorithm for optimization according to the above information, and the decision result is: 18:00-22:00 (peak) execute discharging, discharging power 3kW, last for 4 hours, discharging capacity 12kWh, SOC drops to 80%- (12kWh / 50kWh) 100%=56%; 0:00-6:00 (low valley) execute charging, charging power 3kW, last for 6 hours, charging capacity 18kWh, SOC rises to 56%+ (18kWh / 50kWh) 100%=92%, meet the user's next day demand.

[0028] 18:00, VCU sends discharging instruction to vehicle-mounted charging and discharging device, bidirectional AC / DC converter switches to inverter mode, outputs AC 220V, frequency 50Hz, synchronizes with grid after starting discharging, BMS real-time monitors battery monomer voltage (minimum monomer voltage≥3.0V) and temperature (≤45℃); 19:30 receives temporary peak shaving instruction from grid dispatching center, requires temporarily increasing discharging power to 5kW, lasting for 30 minutes; VCU calculates current state of battery allows (SOC=74%, temperature 28℃), adjusts bidirectional DC / DC converter output current to 41.7A (5kW / 120V), restores to 3kW after 30 minutes; 22:00 discharging ends, accumulative discharging 14kWh; 6:00 charging ends, accumulative charging 18kWh, communication module uploads charging and discharging curve to cloud, cloud calculates user's income according to peak-valley electricity price: discharging income 14kWh×1.2 yuan / kWh=16.8 yuan, charging cost 18kWh×0.3 yuan / kWh=5.4 yuan, net income 11.4 yuan, settlement result is pushed to user's APP.

[0029] The various embodiments described in this specification are described with reference to a particular sequence or order, but the order of the steps can be modified so that particular sequences or orders make no significant contribution to the progress of the art. Moreover, certain features and subcombinations are of utility and can be employed without reference to other features and subcombinations. For purposes of clarity, not every embodiment or feature in this specification is described or shown. Embodiments that provide real benefits can include any embodiment or combination of features described in this specification— even if the range of benefits realized is not the full range of benefits. Those of ordinary skill can understand that information and signals can be represented using any of a variety of technologies and techniques. For the purposes of this description, the terms "information" and "signals" can be regarded as synonymous. Those of ordinary skill can appreciate that the signals can be analog or digital, and the like.

[0030] The foregoing description of the disclosed embodiments enables one of ordinary skill in the art to make or utilize the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without the use of the inventive faculty. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A vehicle-mounted charging and discharging system based on V2G technology, characterized in that, include: The power grid interaction module is used for power grid connection confirmation, overcurrent protection, leakage protection, and grid synchronization detection. The human-machine interaction module displays the charging and discharging settings interface and vehicle power battery status information through the local human-machine interaction interface on the touch screen. Through the mobile terminal APP, it supports users to remotely monitor, issue user commands, and receive intelligent reminders. The communication module is used to enable information exchange with external power grid dispatch centers and cloud management platforms; The on-board charging and discharging module is connected to the vehicle's power battery and is used to regulate the charging and discharging voltage and current of the vehicle's power battery. The battery management module is connected to the on-board charging and discharging module and the vehicle's power battery, and is used to collect the status parameters of the vehicle's power battery. The control center module is connected to the battery management module, communication module, power grid interaction module, and human-machine interaction module, respectively. It is used to monitor the status parameters of the vehicle's power battery in real time, control and protect the charging and discharging process; receive and control the execution of user commands and external power grid dispatch signals; predict the power of the vehicle's power battery based on the real-time status parameters of the vehicle's power battery and user behavior information, generate charging and discharging plans, and provide decision-making basis for power grid dispatch.

2. The vehicle-mounted charging and discharging system based on V2G technology according to claim 1, characterized in that, The communication module supports one or more of the following: 4G / 5G cellular communication, Wi-Fi, Bluetooth, LoRa, or NB-IoT. The information exchanged includes: power grid dispatch instructions, real-time electricity price information, user charging and discharging preference settings, vehicle location information, battery status information, and charging and discharging historical data.

3. The vehicle-mounted charging and discharging system based on V2G technology according to claim 1, characterized in that, The vehicle-mounted charging and discharging module includes an AC interface, a bidirectional AC / DC converter, a DC bus, a bidirectional DC / DC converter, and a battery interface connected in sequence. The AC interface is used to connect to an external AC power grid; The battery interface is used to connect the vehicle's power battery; A bidirectional AC / DC converter is used for bidirectional conversion between AC power from the grid and DC power from a battery. The bidirectional DC / DC converter connects the vehicle's power battery and the bidirectional AC / DC conversion module to regulate charging and discharging voltage and current.

4. The vehicle-mounted charging and discharging system based on V2G technology according to claim 3, characterized in that, The bidirectional AC / DC converter adopts a full-bridge topology, has power factor correction function, can operate in rectification mode and inverter mode, and supports a wide range of AC voltage input. The bidirectional DC / DC converter uses isolated or non-isolated topologies to achieve bidirectional conversion between DC bus voltage and power battery voltage, providing stable charging and discharging current.

5. The vehicle-mounted charging and discharging system based on V2G technology according to claim 1, characterized in that, The battery management module collects the status parameters of the vehicle's power battery, including: individual cell voltage, total voltage, charging and discharging current, battery temperature, state of charge (SOC), state of health (SOH), and available battery capacity.

6. The vehicle-mounted charging and discharging system based on V2G technology according to claim 1, characterized in that, The control center module adopts a multi-core processor architecture and includes: a battery health monitoring unit, a multi-mode control unit, and a power prediction unit; The battery health monitoring unit diagnoses the battery health status based on the state parameters of the vehicle's power battery. The multi-mode control unit provides four operating modes for users to switch freely. The four modes include: Intelligent mode: Automatically generates the optimal charging and discharging strategy based on historical vehicle usage data, real-time power grid information, and weather conditions; Custom mode: Users can manually set the charging / discharging period and power parameters; Platform-hosted mode: The charging and discharging strategy is uniformly scheduled by the cloud platform according to the power grid demand; Emergency standby mode: Provides emergency power to critical loads in the event of power grid failure or natural disaster; The power prediction unit constructs a vehicle power battery power prediction model based on a neural network. It collects historical V2G data, including charging time, discharging time, charging and discharging power, battery SOC changes, and user vehicle usage time, to build a training sample set. The vehicle power battery power prediction model is trained using the training sample set to obtain a trained vehicle power battery power prediction model. Based on real-time input vehicle power battery state parameters and user behavior information, it quickly predicts the vehicle power battery power, providing a decision-making basis for grid dispatch.

7. A vehicle-mounted charging and discharging method based on V2G technology, applied to a vehicle-mounted charging and discharging system based on V2G technology as described in any one of claims 1-6, comprising: S1. After the vehicle is connected to the external power grid, the power grid interaction module performs connection safety detection, including overvoltage, undervoltage, overcurrent, leakage and grounding detection. After the detection is passed, the communication module establishes a communication connection with the power grid dispatch center and cloud management platform. S2. Determine the user's charging and discharging control information through the human-machine interaction module, including: the current working mode of the electric vehicle, the charging and discharging setting information corresponding to the current working mode, and the identity information of the electric vehicle user, and retrieve personalized settings. S3. Obtain real-time electricity price, grid load status, dispatch demand signals and user instructions through the communication module; S4. Obtain the current SOC, SOH, temperature and health parameters of the power battery through the battery management module, and obtain the current status of the vehicle. S5. Select and set the working mode through the control center module to generate a charge / discharge plan, including: charge / discharge start / end time and target SOC; S6. According to the charging and discharging plan, send control commands to the on-board charging and discharging module to control the working mode and power of the bidirectional AC / DC converter and the bidirectional DC / DC converter; S7. When the charging / discharging plan ends, the target SOC is reached, or a termination command is received, the on-board charging / discharging module is controlled to stop working and disconnect from the power grid; the communication module uploads the charging / discharging data to the cloud management platform for electricity bill / subsidy settlement and feeds back the results to the user's mobile terminal APP.

8. The on-board charging and discharging method based on V2G technology according to claim 7, characterized in that, During charging and discharging, the power battery status parameters and grid status are monitored in real time. If the battery overheats, overvoltages, overcurrents, or grid faults occur, the protection mechanism is immediately triggered to interrupt charging and discharging. If the grid dispatch command is updated or the user command is changed, the charging and discharging power is dynamically adjusted or the charging and discharging is terminated.

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