A transient power angle safety control method and device based on virtual synchronous machine control
Patent Information
- Application Number
- CN202610724691.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-05-25
- Publication Date
- 2026-10-13
AI Technical Summary
然而，在逆变器故障穿越场景中，系统动态受控制环节影响较强，且故障期间与故障切除后的模型存在差异，如何建立兼顾工程可实现性与理论可分析性的类能量函数，并据此形成对功率控制具有指导意义的安全集，仍是该领域亟待解决的关键问题
本发明提供了一种基于虚拟同步机控制的暂态功角安全控制方法及装置，包括：求解预先构建的逆变器暂态功角安全修正模型，得到优化结果；利用所述优化结果调节虚拟同步发电机型逆变器的有功控制层的有功功率调节指令；其中，所述优化结果包括：构网型变流器的角频率修正量和功角修正量。本发明提供的技术方案，在有功控制层中引入控制障碍函数约束机制，依据系统状态与安全边界的相对位置，实时修正功率调节指令，使逆变器状态始终限制在预设安全域内，从而有效抑制功角越界、避免暂态失稳，并提升故障后的恢复能力与运行鲁棒性。该方法无需改变主电路结构，能够与现有虚拟同步发电机控制框架兼容，适用于新能源并网变流器、储能变流器及微电网电力电子接口设备。仿真结果表明，本发明能够在故障穿越前后显著提高逆变器暂态功角安全性与系统稳定支撑能力。
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Abstract
Description
Technical Field
[0001] This invention relates to the field of power electronic grid-connected control technology, specifically to a transient power angle safety control method and device based on virtual synchronous machine control. Background Technology With the large-scale integration of new energy power generation devices such as wind power, photovoltaics, and energy storage, the proportion of traditional synchronous generators in the power system continues to decline, and grid-connected equipment with power electronic converters as the interface is gradually becoming the main power source in the power grid. Compared with traditional synchronous machines, power electronic grid-connected devices have advantages such as flexible control, fast response speed, and easy multi-functional integration. However, their physical characteristics mainly rely on control algorithms, and the devices themselves lack the inherent rotational inertia, damping, and electromagnetic coupling support capabilities of synchronous generators. When the power grid is subjected to fault disturbances, if the control strategy is not properly designed, the inverter is prone to problems such as power imbalance, rapid phase angle shift, output limitation, or even instability and grid disconnection, thereby affecting the fault ride-through capability of new energy devices and the safe and stable operation of the power grid.
[0002] To enhance the grid support capabilities of power electronic grid-connected equipment, the Virtual Synchronous Generator (VSG) control method has received widespread attention in recent years. This method introduces the rotor motion equations, damping characteristics, and excitation regulation concepts of a synchronous generator into the control layer, enabling the inverter to simulate the inertial response and frequency and voltage regulation behavior of a synchronous generator in terms of external characteristics. This improves the grid-connected equipment's support capabilities for frequency and voltage, and enhances the system's adaptability to disturbances. Especially in grid-based control and weak grid connection applications, VSG control is considered an effective technical path to improve the active support capabilities of new energy power sources and the grid-friendliness of grid connection.
[0003] Current research on VSG control mainly focuses on steady-state power distribution, inertia and damping parameter design, frequency and voltage support performance optimization, small-signal stability improvement, power coordination in parallel systems, and enhanced adaptability to weak grids. Under normal operating conditions, VSG control enables inverters to exhibit external dynamic characteristics similar to synchronous machines, achieving good results in improving frequency fluctuation suppression, enhancing power sharing accuracy, and strengthening system disturbance rejection capabilities. However, under conditions of large disturbances such as grid voltage dips, line short circuits, and bus faults, the dynamic behavior of VSG-controlled inverters is not entirely consistent with that of synchronous generators. Because the inverter's output capacity is constrained by factors such as current limits, DC-side support capabilities, modulation depth, and control saturation, its electromagnetic power transfer relationship during faults, phase angle evolution, and recovery process after fault clearance become more complex. In such cases, if conventional power regulation methods are still used, relying solely on inertia and damping parameter configuration, it is often difficult to guarantee the inverter's transient power angle safety throughout the entire fault ride-through process.
[0004] Transient power angle safety essentially refers to the ability of the relative power angle between the inverter's equivalent internal electromotive force and the grid connection voltage to remain within an allowable range after a large disturbance in the power grid, and to gradually recover to a stable operating region after the fault is cleared, without continuously increasing, crossing the instability boundary, or causing loss of synchronization. For synchronous generators, transient power angle stability can usually be analyzed using methods such as the oscillation equation, the equal area rule, or the transient energy function. However, for VSG inverters, since their "inertia" and "electromotive force" are constructed by the control system, and the power regulation loop generally incorporates control mechanisms such as current limiting, reactive power support, voltage control, and internal and external loop coupling, the evolution of transient power angle under fault conditions is not only affected by active power imbalance, but also closely related to reactive power regulation methods, voltage support strategies, controller saturation, and the timing of fault clearing. Therefore, traditional synchronous machine transient stability analysis methods cannot be directly applied, and existing research on inverter transient power angle safety is still relatively insufficient.
[0005] In the practice of new energy grid connection projects, to meet grid connection specifications, inverters typically need to have low-voltage ride-through and even continuous high-low voltage ride-through capabilities. When a grid fault causes a sudden voltage drop at the grid connection point, the inverter must not only maintain grid connection but also quickly provide a certain proportion of reactive power support current as required by specifications to assist in voltage recovery in the fault area. During this process, the inverter's output capacity is redistributed, and the control system often prioritizes current limits and reactive power support requirements, thereby compressing the active power regulation capacity available for maintaining power angle stability. Without a reasonable transient safety constraint mechanism, the inverter may accumulate excessive power angle deviation during the fault's duration. Even if the fault is cleared and the voltage recovers, the system state may have already exceeded the safety boundary, ultimately leading to oscillation amplification, power surges, or even grid connection failure.
[0006] From a control theory perspective, ensuring that the inverter state does not cross the unsafe region throughout the fault ride-through process is often insufficient relying solely on post-hoc corrections or empirical parameter tuning. A method that explicitly embeds the "safety boundary" into the controller design is needed. In recent years, control barrier functions (CBFs) have gained increasing attention in the control field due to their ability to directly describe state constraints and provide forward invariance guarantees at the control input level. These methods construct barrier functions corresponding to the safety set, imposing constraints on the control input when the system state approaches the boundary, thus ensuring that the state trajectory remains within the predetermined safety set. For power electronic systems that require real-time prevention of state out-of-bounds movement during operation, control barrier functions offer a potential technical approach that balances dynamic performance and safety constraints. However, existing publicly available technologies lack mature and systematic solutions for constructing a safety set that reflects the transient power angle safety margin, effectively embedding it into the power control layer to achieve online safety constraints, while also considering the dynamic characteristics of VSG inverters under fault conditions.
[0007] Furthermore, for transient stability problems, traditional research often uses energy functions or energy-like Lyapunov functions to describe the relative "energy distance" between the system and the stable equilibrium point, and analyzes whether the state may cross the instability boundary. If this approach can be combined with the dynamic fault model of VSG inverters, it is expected to form an energy-like function-based method suitable for characterizing the transient power angle safety region. By further constructing corresponding safety hyperlevel sets or equivalent boundaries, the abstract "safety margin" can be transformed into a computable, determinable, and real-time control constraint safety set. However, in inverter fault ride-through scenarios, system dynamics are strongly influenced by control elements, and the model differs between the fault period and after fault clearance. How to establish an energy-like function that balances engineering feasibility and theoretical analyzability, and thereby form a safety set that guides power control, remains a key problem that urgently needs to be solved in this field.
[0008] Therefore, there is an urgent need to propose a new method for transient power angle safety control of VSG grid-connected inverters for fault ride-through conditions. Summary of the Invention
[0009] To overcome the above-mentioned defects, this invention proposes a transient power angle safety control method and device based on virtual synchronous machine control.
[0010] Firstly, a transient power angle safety control method based on virtual synchronous machine control is provided, the transient power angle safety control method based on virtual synchronous machine control includes: Solve the pre-built inverter transient power angle safety correction model to obtain the optimization results; The optimization results are used to adjust the active power regulation commands of the active power control layer of the virtual synchronous generator type inverter. The optimization results include: the angular frequency correction and the power angle correction of the grid-type converter.
[0011] Preferably, the pre-built inverter transient power angle safety correction model is as follows:
[0012] In the above formula, This is the angular frequency correction value for grid-type converters. This refers to the angular frequency command in the original active power regulation command. For about The rate of change function, For the control barrier function Extended class K functions, This is the lower limit of the angular frequency for grid-type converters. This is the upper limit of the angular frequency for grid-type converters. , This refers to the power angle adjustment of a grid-type converter. This refers to the angular frequency adjustment of the grid-type converter.
[0013] Furthermore, the aforementioned For the control barrier function The derivative of the control barrier function as follows:
[0014] In the above formula, This is the critical safety threshold. , Equivalent coefficients related to system operating parameters, To adjust the power angle of the grid-type converter The relevant nonlinear potential energy function, This is a class of energy functions for grid-type converters.
[0015] Furthermore, the power angle adjustment amount of the grid-type converter... The relevant nonlinear potential energy function is as follows:
[0016] In the above formula, The magnitude of the grid voltage. The magnitude of the voltage at the grid connection point. For grid connection line inductive reactance, For the current real angle, This is the work angle corresponding to steady state.
[0017] Furthermore, the energy-like function of the grid-type converter is as follows:
[0018] In the above formula, Let be a rotation matrix. .
[0019] Furthermore, the aforementioned control barrier function The extended class K functions are as follows:
[0020] In the above formula, These are preset positive numbers.
[0021] Secondly, a transient power angle safety control device based on virtual synchronous machine control is provided, the transient power angle safety control device based on virtual synchronous machine control comprising: The analysis module is used to solve the pre-built inverter transient power angle safety correction model and obtain the optimization results; The adjustment module is used to adjust the active power adjustment command of the active power control layer of the virtual synchronous generator type inverter using the optimization results; The optimization results include: the angular frequency correction and the power angle correction of the grid-type converter.
[0022] Thirdly, a computer device is provided, comprising: one or more processors; The processor is used to execute one or more programs; When the one or more programs are executed by the one or more processors, the transient power angle safety control method based on virtual synchronous machine control is implemented.
[0023] Fourthly, a computer-readable storage medium is provided, on which a computer program is stored, wherein when the computer program is executed, the transient power angle safety control method based on virtual synchronous machine control is implemented.
[0024] The above-described technical solutions of the present invention have at least one or more of the following beneficial effects: This invention provides a transient power angle safety control method and device based on virtual synchronous generator control, comprising: solving a pre-constructed inverter transient power angle safety correction model to obtain optimization results; and adjusting the active power regulation command of the active power control layer of a virtual synchronous generator inverter using the optimization results; wherein the optimization results include: the angular frequency correction and power angle correction of the grid-connected converter. The technical solution provided by this invention introduces a control barrier function constraint mechanism in the active power control layer, and corrects the power regulation command in real time based on the relative position of the system state and the safety boundary, so that the inverter state is always limited within a preset safety domain, thereby effectively suppressing power angle overflow, avoiding transient instability, and improving post-fault recovery capability and operational robustness. This method does not require changes to the main circuit structure, is compatible with existing virtual synchronous generator control frameworks, and is applicable to new energy grid-connected converters, energy storage converters, and microgrid power electronic interface equipment. Simulation results show that this invention can significantly improve the inverter's transient power angle safety and system stability support capability before and after fault ride-through. Attached Figure Description
[0025] Figure 1 This is a schematic diagram of the main steps of the transient power angle safety control method based on virtual synchronous machine control according to an embodiment of the present invention; Figure 2 This is a comparison curve of active power during fault ride-through according to an embodiment of the present invention; Figure 3 This is a comparison curve of the fault crossing angular frequency according to an embodiment of the present invention; Figure 4 This is a comparison curve of the fault ride-through voltage amplitude according to an embodiment of the present invention. Detailed Implementation
[0026] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.
[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, 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.
[0028] Example 1 See appendix Figure 1 , Figure 1 This is a schematic flowchart illustrating the main steps of a transient power angle safety control method based on virtual synchronous machine control, according to an embodiment of the present invention. Figure 1As shown, the transient power angle safety control method based on virtual synchronous machine control in this embodiment of the invention mainly includes the following steps: Step S101: Solve the pre-built inverter transient power angle safety correction model to obtain the optimization results; Step S102: Adjust the active power regulation command of the active power control layer of the virtual synchronous generator type inverter using the optimization results; The optimization results include: the angular frequency correction and the power angle correction of the grid-type converter.
[0029] In this embodiment, the pre-built inverter transient power angle safety correction model is as follows:
[0030] In the above formula, This is the angular frequency correction value for grid-type converters. This refers to the angular frequency command in the original active power regulation command. For about The rate of change function, For the control barrier function Extended class K functions, This is the lower limit of the angular frequency for grid-type converters. This is the upper limit of the angular frequency for grid-type converters. , This refers to the power angle adjustment of a grid-type converter. This refers to the angular frequency adjustment of the grid-type converter.
[0031] In one implementation, the For the control barrier function The derivative of the control barrier function as follows:
[0032] In the above formula, This is the critical safety threshold. , Equivalent coefficients related to system operating parameters, To adjust the power angle of the grid-type converter The relevant nonlinear potential energy function, This is a class of energy functions for grid-type converters.
[0033] In one embodiment, the power angle adjustment amount of the grid-connected converter The relevant nonlinear potential energy function is as follows:
[0034] In the above formula, The magnitude of the grid voltage. The magnitude of the voltage at the grid connection point. For grid connection line inductive reactance, For the current real angle, This is the work angle corresponding to steady state.
[0035] In one implementation, the energy-like function of the grid converter is as follows:
[0036] In the above formula, Let be a rotation matrix. .
[0037] In one implementation, the control barrier function The extended class K functions are as follows:
[0038] In the above formula, These are preset positive numbers.
[0039] In one specific implementation, from Figure 2 As can be seen, under fault conditions in the 0.5s-1s period, the proposed safety control strategy (Proposed VSG) can ensure stable power and prevent desynchronization oscillation due to excessive power angle. m This refers to active power.
[0040] from Figure 3 As can be seen, under fault conditions in the 0.5s-1s period, the proposed safety control strategy can effectively constrain the system's angular frequency and ensure that the power angle is not too large. n ω is the angular frequency.
[0041] from Figure 4 As can be seen, under the fault state during the period of 0.5s-1s, the proposed safety control strategy can effectively support the voltage amplitude during the fault and ensure the recovery of the fault voltage, and will not cause the voltage to fail to recover due to power angle instability.
[0042] Example 2 Based on the same inventive concept, the present invention also provides a transient power angle safety control device based on virtual synchronous machine control, the transient power angle safety control device based on virtual synchronous machine control comprising: The analysis module is used to solve the pre-built inverter transient power angle safety correction model and obtain the optimization results; The adjustment module is used to adjust the active power adjustment command of the active power control layer of the virtual synchronous generator type inverter using the optimization results; The optimization results include: the angular frequency correction and the power angle correction of the grid-type converter.
[0043] Preferably, the pre-built inverter transient power angle safety correction model is as follows:
[0044] In the above formula, This is the angular frequency correction value for grid-type converters. This refers to the angular frequency command in the original active power regulation command. For about The rate of change function, For the control barrier function Extended class K functions, This is the lower limit of the angular frequency for grid-type converters. This is the upper limit of the angular frequency for grid-type converters. , This refers to the power angle adjustment of a grid-type converter. This refers to the angular frequency adjustment of the grid-type converter.
[0045] Furthermore, the aforementioned For the control barrier function The derivative of the control barrier function as follows:
[0046] In the above formula, This is the critical safety threshold. , Equivalent coefficients related to system operating parameters, To adjust the power angle of the grid-type converter The relevant nonlinear potential energy function, This is a class of energy functions for grid-type converters.
[0047] Furthermore, the power angle adjustment amount of the grid-type converter... The relevant nonlinear potential energy function is as follows:
[0048] In the above formula, The magnitude of the grid voltage. The magnitude of the voltage at the grid connection point. For grid connection line inductive reactance, For the current real angle, This is the work angle corresponding to steady state.
[0049] Furthermore, the energy-like function of the grid-type converter is as follows:
[0050] In the above formula, Let be a rotation matrix. .
[0051] Furthermore, the aforementioned control barrier function The extended class K functions are as follows:
[0052] In the above formula, These are preset positive numbers.
[0053] Example 3 Based on the same inventive concept, this invention also provides a computer device, which includes a processor and a memory. The memory stores a computer program, which includes program instructions. The processor executes the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions in the computer storage medium to implement corresponding method flows or corresponding functions, thereby realizing the steps of a transient power angle safety control method based on virtual synchronous machine control in the above embodiments.
[0054] Example 4 Based on the same inventive concept, this invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device used to store programs and data. It is understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and extended storage media supported by the computer device. The computer-readable storage medium provides storage space that stores the terminal's operating system. Furthermore, this storage space also stores one or more instructions suitable for loading and execution by a processor. These instructions can be one or more computer programs (including program code). It should be noted that the computer-readable storage medium here can be high-speed RAM or non-volatile memory, such as at least one disk storage device. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of the transient power angle safety control method based on virtual synchronous machine control in the above embodiments.
[0055] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.
[0056] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.
[0057] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.
[0058] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.
[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.
Claims
1. A transient power angle safety control method based on virtual synchronous machine control, characterized in that, The method includes: Solve the pre-built inverter transient power angle safety correction model to obtain the optimization results; The optimization results are used to adjust the active power regulation commands of the active power control layer of the virtual synchronous generator type inverter. The optimization results include: the angular frequency correction and the power angle correction of the grid-type converter.
2. The method as described in claim 1, characterized in that, The pre-built inverter transient power angle safety correction model is as follows: In the above formula, This is the angular frequency correction for grid-type converters. This refers to the angular frequency command in the original active power regulation command. For about The rate of change function, For the control barrier function Extended class K functions, This is the lower limit of the angular frequency for grid-type converters. This is the upper limit of the angular frequency for grid-type converters. , This refers to the power angle adjustment amount for grid-type converters. This refers to the angular frequency adjustment of the grid-type converter.
3. The method as described in claim 2, characterized in that, The For the control barrier function The derivative of the control barrier function as follows: In the above formula, This is the critical safety threshold. , Equivalent coefficients related to system operating parameters, To adjust the power angle of the grid-type converter The relevant nonlinear potential energy function, This is a class of energy functions for grid-type converters.
4. The method as described in claim 3, characterized in that, The power angle adjustment amount of the grid-type converter The relevant nonlinear potential energy function is as follows: In the above formula, The magnitude of the grid voltage. The magnitude of the voltage at the grid connection point. For grid connection line inductive reactance, For the current real angle, This is the work angle corresponding to steady state.
5. The method as described in claim 4, characterized in that, The energy-like function of the grid converter is as follows: In the above formula, For rotation matrix, .
6. The method as described in claim 5, characterized in that, Regarding the control barrier function The extended class K functions are as follows: In the above formula, These are preset positive numbers.
7. An apparatus for transient power angle safety control based on virtual synchronous machine control as described in any one of claims 1-6, characterized in that, The device includes: The analysis module is used to solve the pre-built inverter transient power angle safety correction model and obtain the optimization results; The adjustment module is used to adjust the active power adjustment command of the active power control layer of the virtual synchronous generator type inverter using the optimization results; The optimization results include: the angular frequency correction and the power angle correction of the grid-type converter.
8. A computer device, characterized in that, include: One or more processors; The processor is used to execute one or more programs; When the one or more programs are executed by the one or more processors, the transient power angle safety control method based on virtual synchronous machine control as described in any one of claims 1 to 6 is implemented.
9. A computer-readable storage medium, characterized in that, It contains a computer program, which, when executed, implements the transient power angle safety control method based on virtual synchronous machine control as described in any one of claims 1 to 6.