A vehicle-network interaction system

Abstract

This invention relates to the field of new energy vehicle charging technology and discloses a vehicle-to-grid (V2G) interaction system. The system includes a DC bus, a bidirectional rectifier cabinet, multiple heterogeneous charging terminals, and a protocol conversion gateway. The heterogeneous charging terminals are connected in parallel to the DC bus, including newly built charging stations using wide-bandgap devices and upgraded charging stations using silicon-based devices. The protocol conversion gateway calculates a generation coefficient based on device attributes and allocates a virtual impedance inversely proportional to the generation coefficient. The local controller uses the virtual impedance to introduce a virtual voltage drop in the voltage loop, achieving autonomous power allocation. Furthermore, the gateway dynamically corrects the virtual impedance using the integral of the circulating current index to suppress circulating current, and performs black-start optimization of the master control node based on a comprehensive score in islanded mode. This invention effectively solves the problems of uneven power distribution and circulating current when heterogeneous devices are connected in parallel, improving the system's dynamic response capability and power supply reliability.

Description

Technical Field

[0001] This invention relates to the field of new energy vehicle charging technology, specifically a vehicle-to-grid (V2G) interactive system. Background Technology

[0002] With the promotion of vehicle-to-grid (V2G) technology, the expansion of charging stations often faces the situation of existing silicon-based equipment coexisting with newly added wide-bandgap equipment. This heterogeneous parallel system composed of equipment from different generations of technology brings complex control challenges while increasing capacity.

[0003] Due to the significant differences in physical characteristics such as dynamic response and output impedance among heterogeneous devices, traditional control strategies are difficult to adapt. In actual operation, uniform control parameters can easily lead to uneven dynamic power distribution, failing to fully utilize the performance of new equipment, and parameter mismatch can easily induce steady-state circulating currents between parallel nodes on the DC bus. Furthermore, existing technologies lack black-start strategies specifically for the characteristics of heterogeneous sources, and when switching from grid faults to islanded mode, the microgrid voltage often fails to be stably established due to improper selection of the master control node. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a vehicle-to-grid (V2G) interactive system that solves the problems of uneven dynamic power distribution, excessive steady-state circulating current, and low reliability during islanded black-start operation of charging devices from different generations of technology.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a vehicle-to-grid (V2G) interactive system, comprising a DC bus, a bidirectional rectifier cabinet, multiple heterogeneous charging terminals, and a protocol conversion gateway. The bidirectional rectifier cabinet connects the external AC power grid to the DC bus; multiple heterogeneous charging terminals are connected in parallel to the DC bus, including newly built charging piles using wide-bandgap power devices and upgraded charging piles using silicon-based power devices, each heterogeneous charging terminal integrating a local controller; the protocol conversion gateway establishes communication connections with each of the above components.

[0006] The protocol conversion gateway is used to allocate control parameters based on device attributes. Specifically, the gateway obtains the device type and health information of heterogeneous charging terminals, sets a standard generation coefficient for newly built charging piles, and calculates a smaller generation coefficient for upgraded charging piles, thereby generating an initial virtual impedance inversely proportional to the generation coefficient. The local controller introduces a virtual voltage drop in the voltage closed-loop control. This virtual voltage drop is determined by the product of the real-time output current and the virtual impedance, thereby adjusting the output characteristics to allow newly built charging piles to bear more dynamic loads.

[0007] In addition, the protocol conversion gateway also performs circulating current suppression and black start management. During parallel operation, the gateway generates an impedance correction factor based on the integral of the circulating current index exceeding a threshold, dynamically correcting the virtual impedance. In islanded operation, the gateway calculates a score based on a weighted sum of generational coefficients, battery health status, and remaining charge, selecting the primary control node from the terminals connected to the electric vehicle to establish the bus voltage reference. The remaining nodes follow as secondary control nodes, and the gateway allocates virtual inertia compensation power based on the bus voltage change rate.

[0008] This invention provides a vehicle-to-everything (V2X) interactive system. It has the following beneficial effects:

[0009] 1. This invention utilizes a generational coefficient based on the characteristics of power devices to allocate virtual impedance, enabling wide-bandgap devices with better dynamic performance to automatically bear high-frequency fluctuations, while older devices bear the fundamental power. This achieves autonomous power optimization allocation among heterogeneous devices, improves the overall system response speed, and slows down device losses.

[0010] 2. This invention uses virtual impedance secondary correction logic based on the integral of the circulating current index to dynamically adjust the output impedance characteristics of the local controller, effectively compensating for voltage imbalance caused by line differences or device deviations, eliminating steady-state circulating current in parallel systems, and improving operating efficiency.

[0011] 3. This invention constructs a black start mechanism based on a comprehensive score of device and battery status. By optimizing the master control node to establish a voltage reference and introducing virtual inertia control, it ensures the voltage stability of the system during off-grid switching and load changes, thus guaranteeing the reliability of emergency power supply. Attached Figure Description

[0012] Figure 1 This is a system framework diagram of the present invention;

[0013] Figure 2 This is a flowchart of the device generation coefficient identification and initial virtual impedance calculation of the present invention;

[0014] Figure 3 This is a flowchart of the circulating current suppression and secondary power correction of the present invention;

[0015] Figure 4 This is a flowchart illustrating the island detection and black boot mode switching logic of the present invention.

[0016] Among them, 100 is the energy collection center; 110 is the bidirectional rectifier cabinet; 200 is the DC bus; 300 is the heterogeneous charging terminal; 310 is the newly built charging pile; 320 is the renovated charging pile; 400 is the intelligent control center; and 410 is the protocol conversion gateway. Detailed Implementation

[0017] The technical solutions in 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.

[0018] Please see the appendix Figure 1 -Appendix Figure 4 This invention provides a vehicle-to-grid (V2G) interactive system, including an energy collection center 100, a DC bus 200, a heterogeneous charging terminal 300, and an intelligent control center 400.

[0019] The bidirectional rectifier cabinet 110 within the energy collection center 100 connects to the external power grid and the DC bus 200, performing AC / DC conversion to maintain bus voltage and facilitate energy exchange. The DC bus 200 forms a closed-loop topology, connecting the bidirectional rectifier cabinet 110 to various heterogeneous charging terminals 300, creating a DC microgrid for power transmission. The heterogeneous charging terminals 300, including newly built charging piles 310 and upgraded charging piles 320, are connected in parallel to the bus. The newly built charging pile 310 integrates a first bidirectional DC / DC converter, employing high-frequency devices to achieve a first dynamic response speed; the upgraded charging pile 320 adds a second bidirectional DC / DC converter, achieving a second dynamic response speed lower than the first. Both are connected to electric vehicle batteries through their respective converters. The protocol conversion gateway 410 configured in the intelligent control center 400 establishes communication connections with the aforementioned devices, collecting operating parameters and issuing control commands.

[0020] This invention also provides a method for parallel control of heterogeneous devices, which is applied to the above-mentioned system and includes:

[0021] The protocol conversion gateway 410 sets a higher first-generation coefficient for newly built charging piles 310 and a lower second-generation coefficient for upgraded charging piles 320 based on the device attribute matrix. Each converter calculates virtual impedance and adjusts its output accordingly, ensuring that the upgraded charging piles 320 with higher impedance bear the base load, while the newly built charging piles 310 with lower impedance bear the fluctuating load. When the gateway detects circulating current, it fine-tunes the virtual impedance and utilizes droop characteristics to balance bus energy during vehicle-to-vehicle charging. During the black start phase, the gateway prioritizes constant voltage build-up for newly built charging piles 310 based on battery level, health status, and generation coefficient scores, while the remaining devices follow with constant current. Furthermore, the system dynamically adjusts coefficients or limits power based on temperature and battery health to prevent overload.

[0022] The protocol conversion gateway 410 scans each charging terminal node connected to the DC bus 200 in real time via the Controller Area Network (CAN) bus or Ethernet communication interface. When a new device is detected, the protocol conversion gateway 410 sends a device information query command to the target device and receives the device description file from the target device. The device description file includes the device's hardware version number, power module type identifier, and rated output power. and power response time constant Power response time constant Defined as the time required for the device's output power to jump from zero to 90% of its rated power. The protocol conversion gateway 410 constructs a device attribute matrix covering the entire site based on the acquired device description file. Device attribute matrix The physical characteristic parameters of each node are stored in column vector form, specifically as follows:

[0023] ;

[0024] ;

[0025] in, This represents the total number of charging terminals connected to the system. For the first The attribute vector of a charging terminal For the first The rated power of each charging terminal, For the first The power response time constant of each charging terminal For the first The generation coefficient of each charging terminal.

[0026] Protocol conversion gateway 410 uses power module type identifier and power response time constant as the basis for its operation. For generation coefficient Perform the assignment. The assignment process includes the following sub-steps:

[0027] If the identification results indicate that the terminal uses a silicon carbide or gallium nitride wide bandgap semiconductor device, and If the time threshold is less than the preset first time threshold, the terminal is determined to be a newly built pile 310.

[0028] If the identification result indicates that the terminal uses a silicon-based IGBT device, or If the time exceeds the preset second time threshold, the terminal is determined to be a modified pile 320.

[0029] Protocol conversion gateway 410 calculates the generation coefficient based on the judgment result. The calculation formula is as follows:

[0030] ;

[0031] in, For the first The generation coefficient of each charging terminal The preset base reduction factor, The reference response time constant for newly built standard equipment. For the first measured or read The power response time constant of each charging terminal. For the upgraded pile 320, its generation coefficient is inversely proportional to its actual response time constant, thus allowing for the allocation of a larger virtual impedance in subsequent control.

[0032] Protocol conversion gateway 410 will calculate the generation coefficient The coefficient is written into the device attribute matrix and then sent to the local controller of the corresponding first or second bidirectional DC / DC converter via the communication bus. This generation coefficient... As input parameters for subsequent virtual impedance control algorithms, these parameters quantify the weighting of each device's ability to participate in dynamic power regulation. In cases of communication delays or packet loss, the local controller maintains the previously received generation coefficient until a new configuration command is received. For unknown devices that do not provide a device description file, the protocol conversion gateway 410 marks them as retrofit stubs 320 by default and assigns them the minimum allowed generation coefficient. ,Should The system's preset safety fallback value is set to 0.1 in a preferred embodiment to ensure system operation safety.

[0033] The local controller obtains the real-time current at the current converter output through a sampling circuit. and the real-time voltage of DC bus 200 Meanwhile, the local controller reads the generation coefficient issued by the protocol conversion gateway 410 through its internal registers. It reads battery health information through a communication link with the electric vehicle battery management system (BMS). and the battery's current requested power .in, express Index of each charging terminal node.

[0034] The local controller requests power from the battery within a continuous sampling period. Perform differentiation to obtain the rate of change of power demand. For cases with high signal noise, the differentiation process includes low-pass filtering with a cutoff frequency set between 50Hz and 100Hz to filter out high-frequency interference and retain dynamic components that reflect changes in load power.

[0035] The local controller incorporates generational factors, battery health, and the rate of change in power demand into the impedance coupling model. This model uses mathematical functions to map the hardware differences of physical devices and battery status into electrical control parameters. The calculation formula for the impedance coupling model is as follows:

[0036] ;

[0037] in, For the calculated first The virtual impedance value of each charging terminal, in ohms. The preset virtual impedance constant for the system. This is the generation coefficient. It is an exponential function. As a battery aging inhibitor, This is the dynamic damping coefficient. This represents the absolute value of the rate of change in power demand.

[0038] Based on the above formula, when When the battery is severely aged, the index term is lower. The increase leads to a higher calculated virtual impedance. It increases non-linearly. When When the equipment is a modified pile, because it is located in the denominator, it also leads to... Increase.

[0039] The local controller, based on the droop control principle, uses the calculated adaptive virtual impedance value to correct the rated voltage of the DC bus. The correction formula is as follows:

[0040] ;

[0041] in, For the first The output voltage reference value of a charging terminal converter This is the reference value for the rated voltage of the DC bus. For the first The real-time current injected into the bus by each charging terminal For the first Estimated physical impedance of the line from the charging terminal to the common coupling point of the DC bus.

[0042] The local controller will generate The input is sent to the outer loop voltage controller, along with the real-time sampled voltage. The comparison results in an error signal that, after proportional-integral (PI) regulation, serves as the reference signal for the inner current loop. Based on this, the inner current loop controller generates a pulse-width modulation (PWM) signal to drive the power switches of the DC / DC converter.

[0043] Through the above control process, the generation coefficient is... The smaller retrofit pile 320 has a larger virtual impedance. This results in a steeper output voltage-current characteristic curve (VI characteristic). Under the condition of the same DC bus voltage fluctuation, the change in output current of the modified pile 320... The smaller value allows for a more constant power output, avoiding overcurrent faults caused by slow dynamic response. Regarding the generation factor... The newly built 310 busbar has a low virtual impedance and a flat VI characteristic curve, enabling it to respond to small changes in bus voltage and output a large compensation current, thus handling the main power dynamic fluctuations in the system. Simultaneously, it is also important for battery health. For vehicles with poor performance, the system automatically increases the virtual impedance, limiting the current amplitude that the vehicle can interact with the power grid, thus achieving passive protection for aging batteries.

[0044] Protocol conversion gateway 410 calculates the total unbalanced current component within DC bus 200 based on Kirchhoff's current law. For any two parallel-operating... The first charging terminal and the first For each charging terminal, the protocol conversion gateway 410 calculates the circulating current index between the two. The formula for calculating the circulation index is as follows:

[0045] ;

[0046] in, and The first The charging terminal and the first The measured output current of each charging terminal and These are the corresponding rated power values. This formula is used to measure whether the current distribution conforms to the rated power ratio. If If the circulating current exceeds the preset threshold, the system is determined to have a power distribution imbalance.

[0047] Protocol conversion gateway 410 calculates the first Impedance correction factor for each charging terminal This correction factor aims to fine-tune the virtual impedance of the local controller, making its output characteristics approximate the ideal allocation value. The correction factor is calculated using an integral adjustment algorithm, as shown in the following formula:

[0048] ;

[0049] in, For the first Impedance correction factor for each control cycle This is the integral gain coefficient. To control the cycle, This is the current measured current. For the first The ideal target current for each charging terminal is calculated based on the total load demand of the entire site. The power is allocated according to the rated power ratio of each charging terminal:

[0050] ;

[0051] in, This represents the total load power of the system. This is the real-time sampling voltage of the DC bus. This represents the total number of online nodes participating in power allocation.

[0052] Protocol conversion gateway 410 will calculate the impedance correction factor Issued to the The local controller of each charging terminal. After receiving this factor, the local controller adjusts the original virtual impedance value. Update. The update formula is:

[0053] ;

[0054] in, For the revised first The virtual impedance value of each charging terminal. This is the currently effective virtual impedance value before the correction. This is the impedance correction factor.

[0055] By introducing a correction factor, the local controller dynamically adjusts the output impedance of the DC / DC converter, changing the impedance of nodes with large output errors and thus forcing the output current to converge towards the target value. This process is executed periodically and iteratively until the circulating current index is reached. The current is reduced to below a preset threshold to achieve steady-state flow sharing control among heterogeneous devices.

[0056] When the bidirectional rectifier cabinet 110 does not participate in power regulation, the energy balance of the DC bus 200 is entirely maintained by the mounted vehicles. The protocol conversion gateway 410 identifies the source vehicle node in a discharging state and the load vehicle node in a charging state. The local controller of the source vehicle node operates in voltage source mode with droop characteristics, using the aforementioned virtual impedance strategy to adjust the output voltage to adapt to load changes; the local controller of the load vehicle node operates in constant current mode with low-voltage load shedding function. When the source vehicle's virtual impedance decreases due to a drop in battery SOH... As the current increases, its output voltage decreases, leading to a decrease in bus voltage. The load vehicle node detected a decrease in bus voltage. When the current falls below a preset threshold, the low-voltage load shedding logic is triggered, automatically reducing the current request value, thus achieving adaptive balance of source and load power without the need for upper-level communication commands.

[0057] The bidirectional rectifier cabinet 110 integrates an anti-islanding protection module, which monitors the amplitude, frequency, and phase changes of the AC side voltage in real time. When the AC side voltage drop exceeds 20% of the rated value for more than 10ms, or the grid frequency deviates from the 50Hz reference value by more than 0.5Hz, the bidirectional rectifier cabinet 110 determines that an external grid fault has occurred.

[0058] Within 2ms of detecting an external power grid fault, the bidirectional rectifier cabinet 110 immediately controls its internal main circuit breaker to trip, disconnecting the electrical connection with the external AC power grid and preventing microgrid energy from flowing back to the faulty grid. Simultaneously, the bidirectional rectifier cabinet 110 sends an islanding mode trigger signal to the protocol conversion gateway 410 and automatically locks its own rectifier / inverter power modules, stopping energy output to the DC bus 200.

[0059] Upon receiving the islanding mode trigger signal, the protocol conversion gateway 410 immediately broadcasts an emergency standby command to all connected heterogeneous charging terminals 300. Upon receiving the command, the heterogeneous charging terminals 300 temporarily lock their current power output state or switch to a zero-power output standby state to maintain instantaneous bus voltage stability. The protocol conversion gateway 410 detects the residual voltage value of the DC bus 200 using a bus voltage sensor. If the residual voltage value is lower than the system undervoltage threshold, it indicates that the system has lost its main power supply, and a black start procedure must be initiated.

[0060] Protocol conversion gateway 410 retrieves the current device attribute matrix Based on real-time status data, all electric vehicle nodes currently connected and capable of reverse discharge are identified. The criteria for determining reverse discharge capability are: the protocol conversion gateway 410 reads the status of the bidirectional capability flag in the device description file corresponding to the node and confirms that the node has completed the V2G discharge protocol handshake through the BMS. The protocol conversion gateway 410 removes nodes with remaining battery power below a preset safety threshold, and uses the remaining nodes as black-start candidates. This screening process ensures that vehicles participating in black-start have sufficient energy reserves to support microgrid establishment.

[0061] In order to select the most suitable voltage reference establisher in a masterless microgrid, the protocol conversion gateway 410 calculates a comprehensive score for each black-start candidate source. Overall rating The system aims to quantify a device's ability to handle main power supply, and its calculation formula combines device generation attributes, battery health, and remaining power. Overall Score The calculation formula is as follows:

[0062] ;

[0063] in, For the first Black start comprehensive score of each charging terminal. For the first The generation coefficient of each charging terminal For the first Each charging terminal is connected to the vehicle's battery health. For the first Each charging terminal is connected to the vehicle's remaining battery power. , , These are the weighting coefficients for each evaluation dimension.

[0064] Protocol conversion gateway 410 selected based on comprehensive score The node with the highest score is designated as the master node, and all remaining nodes with discharge capabilities are marked as slave nodes. If multiple nodes have the same highest score, one of them is randomly selected, or the node with the smallest access port number is selected as the master node.

[0065] The protocol conversion gateway 410 sends a constant voltage source mode control command to the selected master node, instructing its DC / DC converter to establish the system voltage using a constant voltage control loop with the rated voltage of the DC bus as the reference target. Simultaneously, the protocol conversion gateway 410 sends a controlled current source mode control command to all slave nodes, instructing them to close the outer voltage loop, retain only the inner current loop, and use the power allocation value issued by the protocol conversion gateway 410 as the reference input to output a constant current following the bus voltage. The master node utilizes its high-frequency response and new pile characteristics to quickly stabilize bus voltage fluctuations; the slave nodes utilize their battery capacity to provide continuous energy support. Through this hierarchical support mechanism, the system achieves microgrid black start based on heterogeneous electric vehicle resources without the need for additional independent energy storage power stations.

[0066] In islanded mode, the system's total power generation must match the total load power in real time. Protocol conversion gateway 410 counts the output power of all source nodes. and the power consumption of all load nodes. To maintain system frequency and voltage stability, the following constraints must be met:

[0067] ;

[0068] in, A collection of charging terminals that are in a discharging state. This refers to a collection of charging terminals that are currently charging. For the first The output power of each charging terminal For the first Input power of each charging terminal This refers to line loss power.

[0069] Due to the lack of inertial support from a large power grid, the protocol conversion gateway 410 is equipped with a virtual inertia control module. This module, a processing subsystem consisting of a voltage differential monitoring unit, a total inertia calculation unit, and an inertia allocation unit, is activated in islanded mode to perform inertia compensation. The protocol conversion gateway 410 monitors the DC bus voltage in real time. rate of change When a sudden increase in system load causes a momentary drop in bus voltage, its rate of change is... A negative value indicates a positive value, while a positive value indicates a negative value. This rate of change of voltage reflects the current power surplus / deficit and inertia level of the system.

[0070] To simulate the rotor inertia of a synchronous generator and suppress rapid fluctuations in bus voltage, the protocol conversion gateway 410 introduces virtual capacitor control logic, utilizing the high-frequency response capability of the source node to provide inertia support. The formula for calculating the virtual inertia compensation power is as follows:

[0071] ;

[0072] in, The total inertia compensation power required by the system, This is the real-time bus voltage. The rate of change of bus voltage. This represents the total virtual capacitance of the system. The specific calculation formula is as follows:

[0073] ;

[0074] in, The total capacity of the vehicle-to-everything (V2X) interactive system is set. This is the rated voltage of the DC bus. This is the preset inertial time constant.

[0075] In one specific embodiment of the present invention, the total system capacity is set. =500kW, DC bus rated voltage =750kW. To ensure the microgrid possesses inertial support capabilities comparable to a typical synchronous generator set, the inertial time constant is taken as... =2s, substitute the above values ​​into the formula to calculate the total virtual capacitance of the system. ≈3.55F. The protocol conversion gateway 410 dynamically calculates this based on the total capacity of currently online devices during the initialization phase. The value is then used for subsequent inertia power calculations. In this way, the system can quantitatively simulate the required inertial characteristics, ensuring that the voltage drop rate during sudden load changes remains within a controllable range.

[0076] Due to the varying dynamic response capabilities of different devices, directly distributing the inertia task evenly may lead to overload or oscillation of the retrofitted charging piles. The protocol conversion gateway 410 adjusts the charging pile's operation based on the generation coefficient of each charging terminal. Perform a weighted allocation. Additional inertia power command assigned to each charging terminal The calculation is as follows:

[0077] ;

[0078] in, The total virtual inertia power requirement. For the first The generation coefficient of each charging terminal For the first The rated power of each charging terminal, This refers to the set of all charging terminals currently in a discharging state. For set The first in Device index.

[0079] This allocation strategy ensures the intergenerational coefficient. The newly built piles undertake most of the high-frequency inertial response tasks, while the modified piles with smaller generation coefficients only undertake a small amount of low-frequency power support, thus giving full play to the hardware advantages of heterogeneous equipment.

[0080] No. The local controller of the charging terminal received Then, it is superimposed on the original steady-state power command generated based on droop control to generate the final current loop reference signal. This is done as the bus voltage change rate... Approaching zero, compensation power The power automatically decays to zero, completing a dynamic power regulation process and re-entering steady-state equilibrium. If the bus voltage continues to drop below the safety threshold under maximum inertia compensation, the protocol conversion gateway 410 will trigger low-priority load shedding logic, sequentially transferring loads to the load node set. The system sends a forced shutdown command to vehicles that are charging, or directly controls the DC contactor of the corresponding charging terminal to disconnect until the bus voltage is restored.

[0081] The local controller is embedded within each newly built pile 310 and upgraded pile 320, responsible for executing high-frequency voltage and current dual closed-loop control and virtual impedance calculation. For the newly built pile 310, the local controller adopts a heterogeneous dual-core architecture based on FPGA and DSP. The FPGA is responsible for generating high-frequency PWM signals and fault protection logic, while the DSP is responsible for executing an adaptive virtual impedance algorithm with a control cycle of 100 microseconds to 500 microseconds. For the upgraded pile 320, the local controller reuses the existing MCU resources, upgrades the firmware via ISP interface or OTA technology, and embeds a simplified droop control algorithm.

[0082] The protocol conversion gateway 410, serving as the core coordination unit of the system, is implemented using an embedded industrial computer based on an ARM Cortex-A series processor. This hardware platform integrates multiple heterogeneous communication interfaces, including a CAN-FD interface for connecting newly constructed piles, an RS485 interface for connecting renovated piles, and a PLC communication module for connecting to the BMS. Furthermore, the protocol conversion gateway 410 is equipped with a large-capacity non-volatile memory for storing the device attribute matrix. And historical operation logs. The protocol conversion gateway 410 runs a real-time operating system internally, responsible for periodically performing tasks such as generation coefficient identification, circulation monitoring, and islanding detection.

[0083] To enable interconnection between heterogeneous devices, the protocol conversion gateway 410 integrates a multi-protocol parsing engine. The protocol conversion gateway 410 maps vehicle status data of different protocol formats into a standard internal data frame containing device ID, timestamp, and normalized status value, thereby shielding the differences in underlying communication protocols and enabling upper-layer control algorithms to transparently access the real-time status of any node.

[0084] To ensure coordinated operation of local controllers distributed across different physical locations, the system employs a hierarchical clock synchronization strategy. For newly built piles 310 connected via high-speed Ethernet or CAN-FD, the protocol conversion gateway 410 performs synchronization using the IEEE 1588PTP protocol or a high-precision hardware timer, ensuring that the control cycle start time error is less than 100 microseconds. For upgraded piles 320 connected via RS485, soft synchronization is achieved using application-layer broadcast synchronization messages, ensuring that the execution deviation of system-level scheduling commands is controlled within 10 milliseconds. This hierarchical synchronization mechanism guarantees a high degree of consistency in the actions of core nodes during virtual inertia compensation and black-start grid connection, avoiding system oscillations caused by timing discrepancies.

Claims

1. A vehicle-to-everything (V2X) interactive system, characterized in that, include: DC bus (200) is used to realize power collection and distribution; A bidirectional rectifier cabinet (110) is connected between the external AC power grid and the DC bus (200) to perform AC-DC conversion and grid connection control; Multiple heterogeneous charging terminals (300) are connected in parallel to the DC bus (200). Each heterogeneous charging terminal (300) includes a local controller. The multiple heterogeneous charging terminals (300) include newly built charging piles (310) using wide bandgap power devices and modified charging piles (320) using silicon-based power devices. The protocol conversion gateway (410) establishes a communication connection with the bidirectional rectifier cabinet (110) and each of the heterogeneous charging terminals (300); The protocol conversion gateway (410) is used to obtain the device attributes of each heterogeneous charging terminal (300), calculate the corresponding generation coefficient based on the device attributes, and then allocate a virtual impedance setting value to each heterogeneous charging terminal (300) according to the generation coefficient. The local controller is used to introduce a virtual voltage drop in the voltage control loop based on the virtual impedance setting value to adjust the output voltage characteristics of the heterogeneous charging terminal (300).

2. The vehicle-to-everything (V2X) interactive system according to claim 1, characterized in that, When calculating the generation coefficient, the protocol conversion gateway (410) performs the following steps: Construct a device attribute matrix that includes power device type and commissioning duration; For heterogeneous charging terminals (300) that are shown to use silicon carbide or gallium nitride wide bandgap power devices in the device attribute matrix, the generation coefficient of heterogeneous charging terminals (300) is set to a standard unit value; For heterogeneous charging terminals (300) that use silicon-based IGBT or MOSFET power devices as shown in the device attribute matrix, a generation coefficient less than the standard unit value is calculated based on the depreciation factor of the heterogeneous charging terminal (300) and the nominal life of the system. The generation coefficient reflects the dynamic response capability of the device.

3. The vehicle-to-everything (V2X) interactive system according to claim 2, characterized in that, When allocating the virtual impedance setting value, the protocol conversion gateway (410) performs the following steps: Calculate the system's reference virtual impedance, which is proportional to the system's maximum allowable voltage deviation; Calculate the initial virtual impedance of each of the heterogeneous charging terminals (300), the initial virtual impedance being proportional to the reference virtual impedance and inversely proportional to the generation coefficient of the heterogeneous charging terminals (300); The calculated initial virtual impedance is sent to the corresponding local controller.

4. The vehicle-to-everything (V2X) interactive system according to claim 3, characterized in that, The local controller includes: The virtual impedance calculation unit is used to calculate the virtual voltage drop based on the real-time acquired output current and the virtual impedance set value. A voltage closed-loop control unit is used to obtain a corrected voltage reference value by subtracting the virtual voltage drop from the system reference voltage, and to generate a current reference command based on the deviation between the corrected voltage reference value and the actual bus voltage; and The current closed-loop control unit is used to generate a PWM drive signal based on the deviation between the current reference command and the measured inductor current, so as to control the switching action of the power converter.

5. A vehicle-to-everything (V2X) interactive system according to claim 1, characterized in that, The protocol conversion gateway (410) further includes a loop suppression module, which is used to perform the following steps: The output current of all the heterogeneous charging terminals (300) is periodically collected, and the circulating current index, which reflects the degree of uneven load distribution among parallel nodes, is calculated. When the circulating current index exceeds a preset threshold, an impedance correction factor is calculated, and the impedance correction factor is proportional to the integral of the circulating current index. The virtual impedance setting value is corrected a second time using the impedance correction factor, and the updated virtual impedance setting value is sent to the local controller.

6. The vehicle-to-everything (V2X) interactive system according to claim 1, characterized in that, The bidirectional rectifier cabinet (110) is used to monitor the voltage and frequency of the external AC power grid in real time. When a power grid fault is detected, it controls the grid-connected circuit breaker to open to form an islanding mode and sends an islanding trigger signal to the protocol conversion gateway (410). The protocol conversion gateway (410) responds to the islanding trigger signal to send an emergency standby command to all the heterogeneous charging terminals (300) and monitor the residual voltage status of the DC bus (200).

7. A vehicle-to-everything (V2X) interactive system according to claim 6, characterized in that, The protocol conversion gateway (410) also includes a black-start management module. When the residual voltage of the DC bus (200) is lower than a safety threshold, the black-start management module performs the following steps: Select currently connected electric vehicles with remaining battery power higher than a preset power threshold as candidate sources; A comprehensive score is calculated based on the generation coefficient, battery health status, and remaining power of the heterogeneous charging terminal (300) connected to the candidate source. The heterogeneous charging terminal (300) corresponding to the candidate source with the highest comprehensive score is selected as the master control node, and the heterogeneous charging terminals (300) corresponding to the remaining candidate sources are marked as slave control nodes.

8. A vehicle-to-everything (V2X) interactive system according to claim 7, characterized in that, The protocol conversion gateway (410) is also used to send different control mode commands to the master node and the slave node respectively: The local controller of the master control node responds to the control mode command and switches to the constant voltage source control mode, which is responsible for establishing the voltage and frequency reference of the DC bus (200); The local controller of the slave node responds to the control mode command by switching to the controlled current source control mode, and is responsible for following the voltage of the master node and providing power support.

9. A vehicle-to-everything (V2X) interactive system according to claim 6, characterized in that, The protocol conversion gateway (410) also includes a virtual inertia control module, which, in islanded operation mode, performs the following steps: Real-time monitoring of the voltage change rate of the DC bus (200); Calculate the total inertia compensation power based on the voltage change rate and the preset system virtual capacitance value; The total inertia compensation power is allocated to the local controller of each of the heterogeneous charging terminals (300) according to the product weight of the generation coefficient and the rated power of each heterogeneous charging terminal (300).

10. A vehicle-to-everything (V2X) interactive system according to claim 1, characterized in that, The protocol conversion gateway (410) establishes a communication connection with the newly built pile (310) via the CAN-FD bus and establishes a communication connection with the modified pile (320) via the RS485 bus; The protocol conversion gateway (410) is also used to perform clock synchronization on each of the local controllers via the IEEE1588 protocol or a hierarchical synchronization mechanism, and to control the virtual impedance setting value to take effect at the synchronized clock time.

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