A V2G network switching control method, device, system and readable storage medium

Abstract

This invention provides a V2G grid connection switching control method, device, system, and readable storage medium, relating to the field of V2G grid connection control technology for electric vehicles. The method includes: constructing a voltage and current inner loop structure integrating dual-mode control features (sharing a common current inner loop and generating current reference values ​​for different modes); adding a current command tracking loop; and eliminating phase and voltage errors in the grid connection mode through a closed-loop PI controller. This invention can address the shortcomings of existing grid connection modes operating in weak grids, achieve smooth dual-mode switching, and improve the safety and stability of V2G grid connection.

Description

Technical Field

[0001] This invention relates to the field of V2G grid connection control technology for electric vehicles, and particularly to a V2G network connection switching control method, device, system, and readable storage medium. Background Technology

[0002] To further enhance the active support capabilities of electric vehicles for the power grid, V2G systems with grid-connected charging and discharging control systems have received widespread attention in recent years. Grid-connected V2Gs possess the ability to synchronously track the grid's frequency and voltage, offering more flexible active and reactive power support. In practical operation, V2G grid-connected operation can be divided into two states: grid-following and grid-connecting modes. In grid-following mode, the V2G maintains constant power by adjusting the converter's output current. In grid-connecting mode, the V2G simulates the inertia characteristics of a synchronous generator through virtual synchronous pole control, dynamically supporting the grid frequency by constructing frequency and power droop control and autonomous voltage and frequency regulation. Typically, existing V2Gs mostly adopt the grid-following mode. In grid-following mode, the V2G is highly dependent on the grid voltage and cannot autonomously establish voltage and frequency when grid faults occur, resulting in poor operation capabilities in weak grids. With the large-scale grid connection of distributed renewable energy sources, the safety and stability of the distribution network have been greatly challenged, and the probability of weak grid conditions is much higher than before. If a smooth switching between the V2G system and the network can be achieved, it will help ensure the safe and stable operation of V2G network connection. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the purpose of this invention is to provide a V2G grid connection switching control method, device, system and readable storage medium to solve the shortcomings of the existing grid connection mode in weak grid operation, realize smooth switching between dual modes and improve the safety and stability of V2G grid connection.

[0004] A first aspect of this invention provides a V2G follow-network handover control method, comprising:

[0005] S1: Construct a voltage and current inner loop control structure that integrates the control characteristics of grid-following mode and grid-building mode. The control structure shares the current inner loop in both grid-following mode and grid-building mode. In grid-following mode, a current reference value is generated through the power control loop. In grid-building mode, a current reference value is generated through the voltage control loop.

[0006] S2: Add a current command tracking loop in both the network following mode and the network construction mode, so that the current command of the current operating mode is tracked in real time by the current command of the non-operating mode.

[0007] S3: Phase control in meshing mode: Calculate the difference between the output phase in meshing mode and the output phase in meshing mode, input the difference into the PI controller, and feed the output of the PI controller back to the phase output terminal in meshing mode to eliminate phase error;

[0008] S4: Grid-connected mode voltage control: Calculate the difference between the grid-side voltage component and the system voltage under grid-connected mode, input the difference into the PI controller, and feed back the output of the PI controller to the voltage output terminal of the grid-connected mode to eliminate voltage error.

[0009] In a further embodiment of the present invention, the specific implementation of the voltage and current inner loop control structure in S1 includes:

[0010] In grid-connected mode, based on the set active power reference value P ref Reactive power reference value Q ref and the measured active power value P m Reactive power value Q m The current reference value i is calculated. ref The inner current loop will use the current reference value i ref The difference between the measured current and the actual current of the line is processed by a PI controller to obtain d. q The shaft voltage component is used to regulate the output current in order to control the grid-connected power.

[0011] In network configuration mode, based on the set voltage reference value V ref and the measured voltage value V of the power grid m The current reference value i is calculated. ref The control logic of the inner current loop is consistent with the grid-following mode, by controlling the current reference value i. ref The difference between the measured current and the actual current of the line is processed by a PI controller to obtain d. q The shaft voltage component enables output current regulation to control grid-connected power.

[0012] In a further embodiment of the present invention, the specific operation of the current command tracking loop in S2 includes: taking the difference between the d-axis current reference value and the q-axis current reference value in the network tracking mode and the network construction mode respectively, and the difference is processed by the PI controller to obtain the adjustment amount, so as to realize the smooth transition of the current command.

[0013] In a further embodiment of the present invention, the output phase in the grid-following mode described in S3 is the synchronous control output of the phase-locked loop of the V2G charging and discharging system, and the output phase in the grid-building mode is the output phase θPSL of the virtual synchronous control loop in the grid-building mode. By subtracting θPSL from the output phase θPLL of the phase-locked loop and inputting it into the PI controller, the phase error closed-loop elimination is achieved.

[0014] In a further embodiment of the present invention, the grid-side voltage component in S4 is the d-axis component v of the grid connection point voltage. id and q-axis component v iq In grid-connected mode, the system voltage is the d-axis component v of the inverter voltage of the converter. d and q-axis component v q By v id With v d v iq With v q The difference is calculated separately and then input into a PI controller to achieve closed-loop elimination of voltage error.

[0015] In a further embodiment of the present invention, the voltage and current inner loop control structure integrates a filter inductor and a filter capacitor to filter out high-frequency interference components in the current and voltage signals, thereby ensuring the stability of the control signal.

[0016] In a further embodiment of the present invention, the parameter configuration of the PI controller satisfies the following conditions: the convergence time of phase error and voltage error does not exceed 50ms, the overshoot of current command adjustment is less than 5%, and the dynamic response speed and smoothness requirements during mode switching are ensured.

[0017] A second aspect of the present invention provides a V2G follow-up network handover control device, comprising:

[0018] The integrated control structure construction module is used to construct a voltage and current inner loop control structure that integrates the control characteristics of grid-following mode and grid-building mode, so that the grid-following mode generates a current reference value through the power control link, and the grid-building mode generates a current reference value through the voltage control link.

[0019] The current tracking module is used to add a current command tracking loop in both the grid-following mode and the grid-building mode, so as to realize the real-time tracking of the current command of the current operating mode in the non-operating mode.

[0020] The phase control module is used to calculate the output phase difference between the tracking mode and the network construction mode, and adjusts the phase output of the network construction mode through feedback from the PI controller to eliminate phase error;

[0021] The voltage control module is used to calculate the difference between the grid-side voltage component and the grid-connected system voltage, and adjusts the grid-connected voltage output via feedback from the PI controller to eliminate voltage errors.

[0022] The switching execution module is used to achieve smooth switching between the V2G charging and discharging system and the grid-connecting mode based on the output of the above modules.

[0023] A third aspect of the present invention provides a V2G follow-up network switching control system, comprising: a processor and a memory;

[0024] The memory stores programs or instructions that can run on the processor, which, when executed by the processor, implement the steps of the V2G charging and discharging system control method described in the first aspect of the present invention.

[0025] In a fourth aspect of the present invention, a readable storage medium is provided, on which a program or instruction is stored, which, when executed by a processor, implements the steps of the V2G network connection switching control method described in the embodiments of the first aspect of the present invention.

[0026] The beneficial effects of the technical solutions provided by the embodiments of the present invention include at least the following:

[0027] By constructing a voltage-current inner-loop control structure that integrates the control characteristics of both modes and shares a common current inner loop, the control design is simplified and logic redundancy is reduced. Furthermore, the system can accurately adapt to the power control requirements of the grid-following mode and the voltage control requirements of the grid-connected mode by generating current reference values ​​for each mode. Simultaneously, a current command tracking loop is added, allowing the non-operating mode to track the current command of the current mode in real time, laying the foundation for a smooth transition. Combined with phase and voltage control in the grid-connected mode, phase and voltage errors are eliminated through a closed-loop PI controller. This effectively solves the problems of strong grid dependence and poor operation capability in weak grid scenarios in the existing grid-following mode. It ensures phase synchronization and voltage matching during the switching between the two modes, avoiding grid instability caused by current surges, phase conflicts, or voltage deviations, and significantly improving the grid-connected safety and stability of the V2G charging and discharging system in weak grid scenarios. Attached Figure Description

[0028] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0029] Figure 1 This is a flowchart of the method provided in an embodiment of the present invention.

[0030] Figure 2 This is a schematic diagram of voltage-inner loop control of a V2G system in grid-connected mode provided in an embodiment of the present invention.

[0031] Figure 3 This is a schematic diagram of voltage-inner loop control of a V2G system under network configuration conditions provided in an embodiment of the present invention.

[0032] Figure 4 This is a schematic diagram of the improved V2G system voltage-inner loop control provided in an embodiment of the present invention.

[0033] Figure 5 This is an improved phase control of the V2G charging and discharging system provided in the embodiments of the present invention.

[0034] Figure 6 This is an improved voltage control loop for the V2G charging and discharging system provided in this embodiment of the invention. Detailed Implementation

[0035] To enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention, the technical solutions 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, not all embodiments. It should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0036] The V2G network connection switching control method provided by the present invention will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.

[0037] Reference manual attached Figure 1-6 This invention provides a V2G network handover control method, which may include the following steps:

[0038] S1: Construct a voltage and current inner loop control structure that integrates the control characteristics of grid-following mode and grid-building mode. The control structure shares the current inner loop in both grid-following mode and grid-building mode. In grid-following mode, a current reference value is generated through the power control loop. In grid-building mode, a current reference value is generated through the voltage control loop.

[0039] In one possible implementation, the specific implementation of the voltage and current inner loop control structure in S1 includes:

[0040] In grid-connected mode, based on the set active power reference value P ref Reactive power reference value Q ref and the measured active power value P m Reactive power value Q m The current reference value i is calculated. ref The inner current loop will use the current reference value i ref The difference between the measured current and the actual current of the line is processed by a PI controller to obtain d. q The shaft voltage component is used to regulate the output current in order to control the grid-connected power.

[0041] In network configuration mode, based on the set voltage reference value V ref and the measured voltage value V of the power grid mThe current reference value i is calculated. ref The control logic of the inner current loop is consistent with the grid-following mode, by controlling the current reference value i. ref The difference between the measured current and the actual current of the line is processed by a PI controller to obtain d. q The shaft voltage component enables output current regulation to control grid-connected power.

[0042] In this embodiment, the current reference value is calculated based on the power reference value and the measured value in grid-connected mode, which can accurately regulate the grid-connected power and meet the constant power operation requirements in grid-connected mode. In grid-connected mode, the current reference value is calculated based on the voltage reference value and the measured value, and the current inner loop control logic is consistent with that in grid-connected mode. This reduces the complexity of the control logic, facilitates engineering implementation and debugging, and can generate dq axis voltage components through PI regulation of the current inner loop to achieve fine regulation of the output current. This ensures the stability of the grid-connected power in both modes and avoids adverse effects of power fluctuations on the operation of the power grid or V2G system.

[0043] S2: Add a current command tracking loop in both the network following mode and the network construction mode, so that the current command of the current operating mode is tracked in real time by the current command of the non-operating mode.

[0044] In one possible implementation, the specific operation of the current command tracking loop in S2 includes: taking the difference between the d-axis current reference value and the q-axis current reference value in the tracking mode and the network construction mode respectively, and obtaining the adjustment amount after the difference is processed by the PI controller to achieve a smooth transition of the current command.

[0045] In this embodiment, the d-axis and q-axis current reference values ​​in the following mode and the network construction mode are subtracted and processed by the PI controller. This enables accurate tracking of the current command in two-dimensional components, avoiding current imbalance caused by single-dimensional adjustment. At the same time, the adjustment amount obtained after processing by the PI controller can achieve a smooth transition of the current command, completely solving the impact problem caused by the sudden change of the current command during mode switching. This reduces the mechanical stress and electrical impact on the V2G charging and discharging system and the power grid, and further improves the smoothness and safety of the mode switching process.

[0046] S3: Phase control in meshing mode: Calculate the difference between the output phase in meshing mode and the output phase in meshing mode, input the difference into the PI controller, and feed the output of the PI controller back to the phase output terminal in meshing mode to eliminate phase error;

[0047] In one possible implementation, the output phase in the grid-following mode described in S3 is the synchronous control output of the phase-locked loop of the V2G charging and discharging system, and the output phase in the grid-building mode is the output phase θPSL of the virtual synchronous control loop in the grid-building mode. By subtracting θPSL from the output phase θPLL of the phase-locked loop and inputting it into the PI controller, the phase error closed-loop elimination is achieved.

[0048] In this embodiment, the output phase of the grid-following mode is clearly defined as the output of the phase-locked loop synchronous control, while the output phase of the grid-building mode is defined as the output of the virtual synchronous control loop. This makes the phase error calculation more targeted and accurate, avoiding the failure of error adjustment caused by the ambiguity of the phase definition. Furthermore, by inputting the difference between the two into the PI controller for closed-loop control, the phase error can be accurately eliminated, ensuring that the phases of the two modes are completely synchronized during mode switching. This effectively avoids the risks of grid oscillation and grid disconnection caused by phase conflict, and improves the synchronization accuracy and grid stability of mode switching.

[0049] S4: Grid-connected mode voltage control: Calculate the difference between the grid-side voltage component and the system voltage under grid-connected mode, input the difference into the PI controller, and feed back the output of the PI controller to the voltage output terminal of the grid-connected mode to eliminate voltage error.

[0050] In one possible implementation, the grid-side voltage component in S4 is the d-axis component v of the grid connection point voltage. id and q-axis component v iq In grid-connected mode, the system voltage is the d-axis component v of the inverter voltage of the converter. d and q-axis component v q By v id With v d v iq With v q The difference is calculated separately and then input into a PI controller to achieve closed-loop elimination of voltage error.

[0051] In this embodiment, the dq-axis component of the grid connection point voltage is used as the grid-side voltage component, and the dq-axis component of the inverter voltage is used as the system voltage in the grid-connected mode. By subtracting the components and inputting them into a PI controller for adjustment, two-dimensional precise voltage control is achieved, fully covering the amplitude and phase-related components of the voltage. This avoids the limitations of single-dimensional voltage regulation, can eliminate voltage errors in a closed loop, and ensures that the system voltage in the grid-connected mode is completely matched with the grid-side voltage component. This not only avoids grid-connected voltage fluctuations caused by voltage deviation and improves voltage stability during grid-connected mode operation, but also provides a reliable voltage matching basis for mode switching.

[0052] In one possible implementation, the voltage and current inner loop control structure integrates a filter inductor and a filter capacitor to filter out high-frequency interference components in the current and voltage signals, thereby ensuring the stability of the control signal.

[0053] In this embodiment, high-frequency interference components in current and voltage signals can be effectively filtered out, avoiding the impact of high-frequency noise on the accuracy of control signals, ensuring the stability of key control signals such as current reference value, phase, and voltage, while improving the anti-interference capability of the control structure. This enables the control logic to execute accurately in the complex power grid environment brought about by distributed new energy grid connection, reducing the problems of switching anomalies or control failures caused by interference, and ensuring that the V2G system can operate continuously and reliably under complex operating conditions.

[0054] In one possible implementation, the parameters of the PI controller are configured to meet the following conditions: the convergence time of phase error and voltage error does not exceed 50ms, the overshoot of current command adjustment is less than 5%, and the dynamic response speed and smoothness requirements during mode switching are ensured.

[0055] In this embodiment, the convergence time of phase error and voltage error and the overshoot requirement of current command adjustment are quantified, providing a clear basis for the debugging of control parameters and avoiding the blindness of parameter configuration. This ensures that phase and voltage errors converge quickly, shortens the transition time of mode switching, and improves dynamic response speed. At the same time, it controls the current overshoot within a reasonable range, avoiding system shock caused by overshoot. It fully meets the dual requirements of dynamic response speed and smoothness during mode switching and ensures the reliability of the switching process.

[0056] This invention provides a V2G network connection switching control device, comprising:

[0057] The integrated control structure construction module is used to construct a voltage and current inner loop control structure that integrates the control characteristics of grid-following mode and grid-building mode, so that the grid-following mode generates a current reference value through the power control link, and the grid-building mode generates a current reference value through the voltage control link.

[0058] The current tracking module is used to add a current command tracking loop in both the grid-following mode and the grid-building mode, so as to realize the real-time tracking of the current command of the current operating mode in the non-operating mode.

[0059] The phase control module is used to calculate the output phase difference between the tracking mode and the network construction mode, and adjusts the phase output of the network construction mode through feedback from the PI controller to eliminate phase error;

[0060] The voltage control module is used to calculate the difference between the grid-side voltage component and the grid-connected system voltage, and adjusts the grid-connected voltage output via feedback from the PI controller to eliminate voltage errors.

[0061] The switching execution module is used to achieve smooth switching between the V2G charging and discharging system and the grid-connecting mode based on the output of the above modules.

[0062] In this embodiment, the core control method is decomposed into a fusion control structure construction module, a current tracking module, a phase control module, a voltage control module, and a switching execution module through modular design. The structure is clear and the logic is rigorous, which not only facilitates the design, manufacturing, debugging, and maintenance of the device and lowers the threshold for engineering applications, but also enables the precise implementation of each step of the core control method through the collaborative work of each module. This ensures the efficient realization of functions such as fusion control structure construction, current tracking, and error elimination, and ultimately reliably achieves smooth switching between the two modes of the V2G charging and discharging system, thereby improving the engineering practicality of the core technology.

[0063] This invention provides a V2G network connection switching control system, comprising: a processor and a memory;

[0064] The memory stores programs or instructions that can run on the processor, which, when executed by the processor, implement the steps of the V2G charging and discharging system control method provided in some embodiments of the present invention.

[0065] The above embodiments can be implemented, in whole or in part, by software, hardware (such as circuits), firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, all or part of the processes or functions described in the embodiments of the present invention are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more sets of available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium. A semiconductor medium can be a solid-state drive.

[0066] It should be understood that, in various embodiments of the present invention, the order of the above-mentioned process numbers does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0067] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0068] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the devices, apparatuses, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0069] In the several embodiments provided by this invention, it should be understood that the disclosed devices, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0070] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0071] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0072] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0073] This invention provides a readable storage medium comprising: storing a program or instructions on the readable storage medium, wherein when the program or instructions are executed by a processor, the program or instructions implement the steps of the above-described V2G network connection switching control method and achieve the same technical effect. To avoid repetition, this invention will not elaborate further.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the protection scope of the present invention.

Claims

1. A method for V2G handover control, characterized in that, include: S1: Construct a voltage and current inner loop control structure that integrates the control characteristics of grid-following mode and grid-building mode. The control structure shares the current inner loop in both grid-following mode and grid-building mode. In grid-following mode, a current reference value is generated through the power control loop. In grid-building mode, a current reference value is generated through the voltage control loop. S2: Add a current command tracking loop in both the network following mode and the network construction mode, so that the current command of the current operating mode is tracked in real time by the current command of the non-operating mode. S3: Phase control in meshing mode: Calculate the difference between the output phase in meshing mode and the output phase in meshing mode, input the difference into the PI controller, and feed the output of the PI controller back to the phase output terminal in meshing mode to eliminate phase error; S4: Grid-connected mode voltage control: Calculate the difference between the grid-side voltage component and the system voltage under grid-connected mode, input the difference into the PI controller, and feed back the output of the PI controller to the voltage output terminal of the grid-connected mode to eliminate voltage error. 2.The V2G follow-me network switching control method of claim 1, wherein, The specific implementation of the voltage and current inner loop control structure described in S1 includes: In the grid-connected mode, based on the set active power reference value P ref , the reactive power reference value Q ref , and the measured active power value P m , the reactive power value Q m , the current reference value i ref is calculated; the current inner loop subtracts the measured line current from the current reference value i ref , and the difference is processed by a PI controller to obtain the d q -axis voltage component, so as to realize output current regulation to control the grid-connected power; In the grid-connected mode, based on the set voltage reference value V ref and the actual grid voltage value V m , the current reference value i ref is calculated; the control logic of the current inner loop is consistent with the grid-connected mode, and the difference between the current reference value i ref and the actual line current is processed by a PI controller to obtain the d q -axis voltage component, realizing output current regulation to control the grid-connected power. 3.The V2G follow-me network switching control method of claim 1, wherein, The specific operation of the current command tracking loop described in S2 includes: taking the difference between the d-axis current reference value and the q-axis current reference value in the following mode and the network construction mode respectively, and obtaining the adjustment amount after the difference is processed by the PI controller to achieve a smooth transition of the current command. 4.The V2G follow-me network switching control method of claim 1, wherein, The output phase in the grid-following mode described in S3 is the synchronous control output of the phase-locked loop of the V2G charging and discharging system. The output phase in the grid-building mode is the output phase θPSL of the virtual synchronous control loop in the grid-building mode. By subtracting θPSL from the output phase θPLL of the phase-locked loop and inputting it into the PI controller, the phase error closed-loop elimination is achieved. 5.The V2G follow-me network switching control method of claim 1, wherein, The grid-side voltage component in S4 is the d-axis component v of the grid point voltage id and the q-axis component v iq The system voltage in the grid-forming mode is the d-axis component v of the inverter inversion voltage d and the q-axis component v q The voltage error closed loop is eliminated by inputting the PI controller through the difference between v id and v d , v iq and v q respectively. 6.The V2G follow-me network switching control method of claim 1, wherein, The voltage and current inner loop control structure integrates a filter inductor and a filter capacitor to filter out high-frequency interference components in the current and voltage signals, ensuring the stability of the control signal. 7.The V2G follow-me network switching control method of claim 1, wherein, The parameters of the PI controller are configured to meet the following conditions: the convergence time of phase error and voltage error does not exceed 50ms, the overshoot of current command adjustment is less than 5%, and the dynamic response speed and smoothness requirements during mode switching are ensured. 8.A V2G follow-me network switching control device, characterized in that, include: The integrated control structure construction module is used to construct a voltage and current inner loop control structure that integrates the control characteristics of grid-following mode and grid-building mode, so that the grid-following mode generates a current reference value through the power control link, and the grid-building mode generates a current reference value through the voltage control link. The current tracking module is used to add a current command tracking loop in both the grid-following mode and the grid-building mode, so as to realize the real-time tracking of the current command of the current operating mode in the non-operating mode. The phase control module is used to calculate the output phase difference between the tracking mode and the network construction mode, and adjusts the phase output of the network construction mode through feedback from the PI controller to eliminate phase error; The voltage control module is used to calculate the difference between the grid-side voltage component and the grid-connected system voltage, and adjusts the grid-connected voltage output via feedback from the PI controller to eliminate voltage errors. The switching execution module is used to achieve smooth switching between the V2G charging and discharging system and the grid-connecting mode based on the output of the above modules. 9.A V2G handover control system, characterized in that, include: Processor and memory; The memory stores programs or instructions that can run on the processor, which, when executed by the processor, implement the steps of the V2G network connection handover control method as described in any one of claims 1 to 7.

10. A readable storage medium, characterized in that, The readable storage medium stores a program or instructions that, when executed by a processor, implement the steps of the V2G network connection switching control method as described in any one of claims 1 to 7.

Images