Active Support Control Method and Device for Network-Forming Converter Based on Frequency-Voltage Coupling

Abstract

The present invention discloses an active support control method and device for a network-forming converter based on frequency-voltage coupling, including: obtaining system parameters and operating condition parameters of the network-forming converter for calculating additional control parameters, calculating the operating power angle of the network-forming converter according to the power angle between AC power grids and the power angle generated by a conventional active support control algorithm, and respectively constructing a steady-state model and a small-signal stability model of the network-forming converter based on the obtained parameters and the operating power angle; constructing an additional steady-state control structure according to the mathematical relationship in the steady-state model, and calculating the steady-state decoupling coefficient in the additional steady-state control structure on the condition that the non-diagonal elements in the steady-state control are zero; constructing an additional dynamic control structure according to the mathematical relationship in the small-signal stability model, and calculating the dynamic decoupling coefficient in the additional dynamic control structure on the condition that the non-diagonal elements in the dynamic control are zero; performing fusion decoupling control on the network-forming converter based on the steady-state decoupling coefficient and the dynamic decoupling coefficient.

Description

Technical Field

[0001] The present invention belongs to the field of converters, and relates to a control method for a grid-forming converter, and particularly to an active support control method and device for a grid-forming converter based on frequency-voltage coupling. Background Art

[0002] In a power system with high penetration of power electronics, the control actions and control processes of power electronic systems such as new energy power generation devices and flexible DC equipment are complex, which deeply affects the dynamic response characteristics of the power system, making the operation and control of the power system with high penetration of power electronics face great challenges.

[0003] To improve the safety and stability performance of a power system with high penetration of power electronics, the use of a grid-forming converter is an effective and economical means. The grid-forming converter can actively establish the frequency and voltage of the system and does not need to track the grid frequency. Therefore, it can not only operate in the grid-connected mode but also in the active support mode. Generally, the synchronization strategy of the grid-forming converter is similar to that of a traditional synchronous generator control. By simulating the power-frequency and voltage characteristics of a synchronous generator and designing reasonable frequency and voltage control loops, the external characteristics of the entire converter port can be regarded as a synchronous generator, and flexible networking can be carried out accordingly.

[0004] However, in the related art, the coupling characteristics between the frequency and voltage of the grid-forming converter under active support control are usually ignored, resulting in the coupling of active power and reactive power. When the power changes, power oscillations will occur. Coupled with unreasonable system parameters, the above oscillations are likely to be amplified, leading to system instability. Summary of the Invention

[0005] In view of this, the present invention discloses an active support control method, device, equipment, and storage medium for a grid-forming converter based on frequency-voltage coupling, which can solve the deficiencies existing in the related art.

[0006] To achieve the above object, the present invention discloses the following technical solutions:

[0007] According to the first aspect of the present invention, an active support control method for a grid-forming converter based on frequency-voltage coupling is proposed, characterized in that the method includes:

[0008] Obtain the system parameters and operating condition parameters of the grid-forming converter for calculating additional control parameters; wherein, the system parameters include: the equivalent voltage VC on the AC side inside the converter, the equivalent inductance LC on the AC side inside the converter, the equivalent resistance RC on the AC side inside the converter, the PI parameters of the active power synchronization control loop, the PI parameters of the AC voltage control loop, the PI parameters of the reactive power synchronization control loop, and the operating condition parameters include: the equivalent voltage V of the AC grid connected to the converter g, the equivalent inductance L of the AC grid connected to the converter g , the equivalent resistance Rg of the AC grid connected to the converter, the active power P exchanged between the converter and the AC grid, the reactive power Q exchanged between the converter and the AC grid, the reactive power wg exchanged between the AC grids, and the power angle θ g , the power angle θ generated by the conventional active support control algorithm 旧 * ;

[0009] According to the power angle θ between the AC grids g and the power angle θ generated by the conventional active support control algorithm 旧 * Calculate the operating power angle θ of the network-forming converter, and respectively construct a steady-state model and a small-signal stability model of the network-forming converter according to the obtained parameters and the operating power angle θ;

[0010] Construct an additional steady-state control structure according to the mathematical relationship in the steady-state model, and calculate the steady-state decoupling coefficient in the additional steady-state control structure on the condition that the non-diagonal elements in the steady-state control are zero;

[0011] Construct an additional dynamic control structure according to the mathematical relationship in the small-signal stability model, and calculate the dynamic decoupling coefficient in the additional dynamic control structure on the condition that the non-diagonal elements in the dynamic control are zero;

[0012] Perform fusion decoupling control on the network-forming converter based on the steady-state decoupling coefficient and the dynamic decoupling coefficient.

[0013] According to the second aspect of the present invention, a network-forming converter active support control device based on frequency-voltage coupling is proposed, characterized in that the device includes:

[0014] An acquisition unit: acquire the system parameters and operating condition parameters of the network-forming converter for calculating additional control parameters; wherein, the system parameters include: the equivalent voltage VC on the AC side inside the converter, the equivalent inductance LC on the AC side inside the converter, the equivalent resistance RC on the AC side inside the converter, the PI parameters of the active power synchronization control loop, the PI parameters of the AC voltage control loop, the PI parameters of the reactive power synchronization control loop, and the operating condition parameters include: the equivalent voltage V of the AC grid connected to the converter g , the equivalent inductance L of the AC grid connected to the converter g , the equivalent resistance Rg of the AC grid connected to the converter, the active power P exchanged between the converter and the AC grid, the reactive power Q exchanged between the converter and the AC grid, the reactive power wg exchanged between the AC grids, and the power angle θ g , the power angle θ generated by the conventional active support control algorithm 旧 * ;

[0015] Calculation unit: Based on the power angle θ between AC power grids g and the power angle θ generated by the conventional active support control algorithm 旧 * Calculate the operating power angle θ of the network-forming converter, and respectively construct a steady-state model and a small-signal stability model of the network-forming converter according to the obtained parameters and the operating power angle θ;

[0016] First construction unit: Construct an additional steady-state control structure according to the mathematical relationship in the steady-state model, and calculate the steady-state decoupling coefficient in the additional steady-state control structure on the condition that the non-diagonal elements in the steady-state control are zero;

[0017] Second construction unit: Construct an additional dynamic control structure according to the mathematical relationship in the small-signal stability model, and calculate the dynamic decoupling coefficient in the additional dynamic control structure on the condition that the non-diagonal elements in the dynamic control are zero;

[0018] Control unit: Perform fusion decoupling control on the network-forming converter based on the steady-state decoupling coefficient and the dynamic decoupling coefficient.

[0019] According to the third aspect of the present invention, an electronic device is proposed, including:

[0020] A processor;

[0021] A memory for storing instructions executable by the processor;

[0022] Wherein, the processor realizes the steps of the method as described in the first aspect by running the executable instructions.

[0023] According to the fourth aspect of the present invention, a computer-readable storage medium is proposed, on which computer instructions are stored, and when the instructions are executed by a processor, the steps of the method as described in the first aspect are realized.

[0024] As can be seen from the above technical solutions, the active support control method for the network-forming converter based on frequency-voltage coupling disclosed in the present invention takes into account the coupling characteristics of frequency-voltage, constructs a steady-state model and a small-signal stability model of the network-forming converter according to the obtained system parameters and operating condition parameters of the network-forming converter, and further constructs an additional steady-state control structure and an additional dynamic control structure, so as to calculate the steady-state decoupling coefficient and the dynamic decoupling coefficient for realizing decoupling control. It can not only effectively solve the active-reactive decoupling in the steady-state operation under the active support control mode of the network-forming converter, reduce the coordination control difficulty of related systems, but also effectively solve the active-reactive decoupling in the dynamic operation under the active support control mode of the network-forming converter, ensure the multi-condition safe and stable operation of related systems, and reduce the impact voltage and current during condition switching. Description of the Drawings

[0025] Figure 1It is a schematic diagram of the active and reactive power regulation coupling phenomenon under the conventional active support control of a network-forming converter provided by an exemplary embodiment.

[0026] Figure 2 It is a flowchart of an active support control method for a network-forming converter based on frequency-voltage coupling provided by an exemplary embodiment.

[0027] Figure 3 It is a schematic diagram of an additional control structure provided by an exemplary embodiment.

[0028] Figure 4 It is a schematic structural diagram of a device provided by an exemplary embodiment.

[0029] Figure 5 It is a block diagram of an active support control device for a network-forming converter based on frequency-voltage coupling provided by an exemplary embodiment. Detailed implementation manners

[0030] Here, the exemplary embodiments will be described in detail, and the examples are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with one or more embodiments of the present invention. On the contrary, they are merely examples of devices and methods consistent with some aspects of one or more embodiments of the present invention as detailed in the appended claims.

[0031] It should be noted that: in other embodiments, the steps of the corresponding methods are not necessarily executed in the order shown and described in the present invention. In some other embodiments, the steps included in the method may be more or less than those described in the present invention. In addition, a single step described in the present invention may be decomposed into multiple steps for description in other embodiments; and multiple steps described in the present invention may also be combined into a single step for description in other embodiments.

[0032] To further illustrate the present invention, the following embodiments are provided:

[0033] In a power electronics high-penetration power system, the control actions and control processes of power electronics systems such as new energy power generation devices and flexible DC equipment are complex, which deeply affect the dynamic response characteristics of the power system, making the operation and control of the power electronics high-penetration power system face huge challenges.

[0034] To improve the security and stability performance of a power electronics high-penetration power system, the use of a network-forming converter is an effective and economical means. The network-forming converter can actively establish the system frequency and voltage without tracking the grid frequency. Therefore, it can not only operate in the grid-connected mode but also in the active support mode. Generally, the synchronization strategy of the network-forming converter is similar to that of a traditional synchronous generator control. By simulating the power-frequency and voltage characteristics of the synchronous generator and designing a reasonable frequency and voltage control loop, the external characteristics of the entire converter port can be regarded as a synchronous generator, and flexible network formation can be carried out accordingly.

[0035] However, in the related art, the coupling characteristics of the frequency and voltage of the network-forming converter itself under active support control are usually ignored, resulting in the coupling of its active and reactive power. When the power changes, power oscillations will occur. Coupled with unreasonable system parameters, the above oscillations are likely to be amplified, leading to system instability.

[0036] As Figure 1 shown, the coupling phenomenon of active and reactive power regulation under the conventional active support control of the network-forming converter is given. Obviously, due to the lack of consideration of the frequency-voltage coupling characteristics, there is a coupling phenomenon in the active and reactive power regulation of the network-forming converter under the conventional active support control, resulting in large oscillations in the reactive power when the active power is adjusted. In this way, when the network-forming converter operates under diverse working conditions, the above oscillations may be further coupled due to the interaction with other system parameters, generating continuous oscillations that endanger the system security.

[0037] To solve the deficiencies in the related art, the present invention proposes an active support control method for a network-forming converter based on frequency-voltage coupling.

[0038] Figure 2 is a flowchart of an active support control method for a network-forming converter based on frequency-voltage coupling provided by an exemplary embodiment. As Figure 2 shown, the method may include the following steps:

[0039] Step 202, obtaining the system parameters and operating condition parameters of the network-forming converter for calculating additional control parameters; wherein, the system parameters include: the equivalent voltage VC of the internal AC side of the converter, the equivalent inductance LC of the internal AC side of the converter, the equivalent resistance RC of the internal AC side of the converter, the PI parameters of the active power synchronization control loop, the PI parameters of the AC voltage control loop, the PI parameters of the reactive power synchronization control loop, and the operating condition parameters include: the equivalent voltage V of the AC power grid connected to the converter g 、the equivalent inductance L of the AC power grid connected to the converter g, the equivalent resistance Rg of the AC power grid connected to the converter, the active power P exchanged between the converter and the AC power grid, the reactive power Q exchanged between the converter and the AC power grid, the reactive power wg exchanged between the AC power grids, and the power angle θ g , the power angle θ generated by the conventional active support control algorithm 旧 * .

[0040] Step 204, according to the power angle θ between the AC power grids g and the power angle θ generated by the conventional active support control algorithm 旧 * Calculate the operating power angle θ of the network-forming converter, and respectively construct the steady-state model and small-signal stability model of the network-forming converter according to the obtained parameters and the operating power angle θ.

[0041] In one embodiment, the power angle θ between the AC power grids g and the power angle θ generated by the conventional active support control algorithm 旧 * Calculate the operating power angle θ of the network-forming converter, including: calculating the difference between the power angle θ between the AC power grids g and the power angle θ generated by the conventional active support control algorithm 旧 * and using the attack angle difference as the operating power angle θ of the network-forming converter, which is expressed by the formula as:

[0042] .

[0043] In one embodiment, according to the relevant parameters obtained in step 202 and the operating power angle θ of the network-forming converter, calculate the steady-state model of the network-forming converter to obtain the active and reactive coupling coefficients (i.e., mathematical relationships) of the network-forming converter under steady state, and the specific calculation is as follows:

[0044] ;

[0045] Among them, the steady-state model takes the operating power angle θ and the grid voltage Vs as inputs, and the active power P and reactive power Q as outputs. XJ θP (steady state) is the mathematical relationship between the active power P and the operating power angle θ, XJ VP (steady state) is the mathematical relationship between the active power P and the grid voltage Vs, XJ θQ (steady state) is the mathematical relationship between the reactive power Q and the operating power angle θ, XJ VQ (steady state) is the mathematical relationship between the reactive power Q and the grid voltage Vs.

[0046] It should be noted that since the lines in the power grid usually contain resistance and inductance, the above XJ θP (steady state), XJ VP (steady state), XJ θQ (steady state), XJ VQThe (steady state) is usually non-linear and non-independent, so it needs to be obtained by fitting a polynomial function based on the curve scanning method, and there is no unique expression form.

[0047] In one embodiment, according to the relevant parameters obtained in step 202 and the operating power angle θ of the network-forming converter, calculate the small-signal stability model of the network-forming converter to obtain the active and reactive coupling coefficients (i.e., mathematical relationships) of the network-forming converter under small signals. The specific calculation is as follows:

[0048] ;

[0049] Among them, with the small-signal increment ∆P of the active power P and the small-signal increment ∆Q of the reactive power Q as the outputs, the small-signal increment ∆θ of the operating power angle θ of the network-forming converter and the small-signal increment ∆V of the grid voltage Vs s are the inputs, XJ θP (dynamic) is the mathematical relationship between the active power P and the operating power angle θ, XJ VP (dynamic) is the mathematical relationship between the active power P and the grid voltage Vs, XJ θQ (dynamic) is the mathematical relationship between the reactive power Q and the operating power angle θ, XJ VQ (dynamic) is the mathematical relationship between the reactive power Q and the grid voltage Vs.

[0050] It should be noted that similar to the above XJ θP (steady state), XJ VP (steady state), XJ θQ (steady state), XJ VQ (steady state), XJ θP (dynamic), XJ VP (dynamic), XJ θQ (dynamic), XJ VQ (dynamic) is usually also non-linear and non-independent, so it also needs to be obtained by fitting a polynomial function based on the curve scanning method, and there is no unique expression form.

[0051] Step 206, construct an additional steady-state control structure according to the mathematical relationship in the steady-state model, and calculate the steady-state decoupling coefficient in the additional steady-state control structure on the condition that the non-diagonal elements in the steady-state control are zero.

[0052] Step 208, construct an additional dynamic control structure according to the mathematical relationship in the small-signal stability model, and calculate the dynamic decoupling coefficient in the additional dynamic control structure on the condition that the non-diagonal elements in the dynamic control are zero.

[0053] As Figure 3 shown, the calculation formulas for the steady-state decoupling coefficient and the dynamic decoupling coefficient are respectively:

[0054] ;

[0055] Among them, FJ Vθ (steady state) is the steady-state decoupling coefficient of the active power P and the operating voltage V, and FJ θV (steady state) is the steady-state decoupling coefficient of the reactive power Q and the operating power angle θ.

[0056] ;

[0057] Among them, FJ Vθ (dynamic) is the dynamic decoupling coefficient of the active power P and the operating voltage V, and FJ θV (dynamic) is the dynamic decoupling coefficient of the reactive power Q and the operating power angle θ.

[0058] Step 210, perform fusion decoupling control on the network-forming converter based on the steady-state decoupling coefficient and the dynamic decoupling coefficient.

[0059] In one embodiment, the performing fusion decoupling control on the network-forming converter based on the steady-state decoupling coefficient and the dynamic decoupling coefficient includes:

[0060] Construct a fusion decoupling model according to the steady-state decoupling coefficient and the dynamic decoupling coefficient, and perform fusion decoupling control based on the fusion decoupling model. The fusion decoupling model is:

[0061] ;

[0062] Among them, FJ Vθ (steady state) is the steady-state decoupling coefficient of the active power P and the operating voltage V, and FJ θV (steady state) is the steady-state decoupling coefficient of the reactive power Q and the operating power angle θ, and FJ Vθ (dynamic) is the dynamic decoupling coefficient of the active power P and the operating voltage V, and FJ θV (dynamic) is the dynamic decoupling coefficient of the reactive power Q and the operating power angle θ, is the power angle generated by the conventional active support control algorithm, is the voltage generated by the conventional active support control algorithm, is the power angle generated by the fusion additional decoupling control algorithm, is the voltage generated by the fusion additional decoupling control algorithm.

[0063] In this embodiment, the coupling characteristics of frequency-voltage are considered. Based on the obtained system parameters and operating condition parameters of the network-forming converter, a steady-state model and a small-signal stability model of the network-forming converter are constructed, and an additional steady-state control structure and an additional dynamic control structure are further constructed. Thus, the steady-state decoupling coefficient and the dynamic decoupling coefficient for realizing decoupling control are calculated, which can not only effectively solve the active-reactive decoupling in the steady-state operation under the active support control mode of the network-forming converter, reduce the coordination control difficulty of the relevant system, but also effectively solve the active-reactive decoupling in the dynamic operation under the active support control mode of the network-forming converter, ensure the multi-condition safe and stable operation of the relevant system, and reduce the impact voltage and current during the condition switching.

[0064] Figure 4 is a schematic structural diagram of a device provided by an exemplary embodiment. Please refer to Figure 4 , at the hardware level, the device includes a processor 402, an internal bus 404, a network interface 406, a memory 408, and a non-volatile memory 410. Of course, there may also be other hardware required for other functions. One or more embodiments of the present invention can be implemented in a software manner. For example, the processor 402 reads the corresponding computer program from the non-volatile memory 410 into the memory 408 and then runs it. Of course, in addition to the software implementation manner, one or more embodiments of the present invention do not exclude other implementation manners, such as a logic device or a combination of software and hardware, etc. That is to say, the execution subject of the following processing flow is not limited to each logic unit, and can also be hardware or a logic device.

[0065] Please refer to Figure 5 , a network-forming converter active support control device based on frequency-voltage coupling can be applied to a device such as Figure 5 shown to implement the technical solution of the present invention. The device may include:

[0066] An acquisition unit 502, configured to acquire the system parameters and operating condition parameters of the network-forming converter for calculating additional control parameters; wherein, the system parameters include: the equivalent voltage VC on the internal AC side of the converter, the equivalent inductance LC on the internal AC side of the converter, the equivalent resistance RC on the internal AC side of the converter, the PI parameters of the active power synchronization control loop, the PI parameters of the AC voltage control loop, the PI parameters of the reactive power synchronization control loop, and the operating condition parameters include: the equivalent voltage V of the AC power grid connected to the converter g , the equivalent inductance L of the AC power grid connected to the converter g , the equivalent resistance Rg of the AC power grid connected to the converter, the exchanged active power P between the converter and the AC power grid, the exchanged reactive power Q between the converter and the AC power grid, the exchanged reactive power wg between the AC power grids, the power angle θ g , the power angle θ generated by the conventional active support control algorithm 旧* ;

[0067] A calculation unit 504, configured to generate a power angle θ* of the network-forming converter according to the power angle θ between the AC power grids and the power angle θ generated by a conventional active support control algorithm; g and the power angle θ 旧 * calculate the operating power angle θ of the network-forming converter, and respectively construct a steady-state model and a small-signal stability model of the network-forming converter according to the obtained parameters and the operating power angle θ;

[0068] A first construction unit 506, configured to construct an additional steady-state control structure according to the mathematical relationship in the steady-state model, and calculate a steady-state decoupling coefficient in the additional steady-state control structure on the condition that non-diagonal elements in the steady-state control are zero;

[0069] A second construction unit 508, configured to construct an additional dynamic control structure according to the mathematical relationship in the small-signal stability model, and calculate a dynamic decoupling coefficient in the additional dynamic control structure on the condition that non-diagonal elements in the dynamic control are zero;

[0070] A control unit 510, configured to perform a fusion decoupling control on the network-forming converter based on the steady-state decoupling coefficient and the dynamic decoupling coefficient.

[0071] Optionally, the calculation unit 504 is specifically configured to:

[0072] calculate the difference between the power angle θ between the AC power grids and the power angle θ generated by the conventional active support control algorithm, and use the power angle difference as the operating power angle θ of the network-forming converter. g and the power angle θ 旧 * generated by the conventional active support control algorithm, and use the power angle difference as the operating power angle θ of the network-forming converter.

[0073] Optionally, the steady-state model is as follows:

[0074] ;

[0075] wherein, the steady-state model takes the operating power angle θ and the grid voltage Vs as inputs, and takes the active power P and the reactive power Q as outputs, XJ θP (steady state) is the mathematical relationship between the active power P and the operating power angle θ, XJ VP (steady state) is the mathematical relationship between the active power P and the grid voltage Vs, XJ θQ (steady state) is the mathematical relationship between the reactive power Q and the operating power angle θ, XJ VQ (steady state) is the mathematical relationship between the reactive power Q and the grid voltage Vs.

[0076] Optionally, the calculation formula for calculating the steady-state decoupling coefficient is as follows:

[0077] ;

[0078] wherein, FJVθ (Steady state) is the steady-state decoupling coefficient of active power P and operating voltage V, FJ θV (Steady state) is the steady-state decoupling coefficient of reactive power Q and operating power angle θ.

[0079] Optionally, the small-signal stability model is as follows:

[0080] ;

[0081] Among them, with the small-signal increment ∆P of active power P and the small-signal increment ∆Q of reactive power Q as the outputs, the small-signal increment ∆θ of the operating power angle θ of the network-forming converter and the small-signal increment ∆V of the grid voltage Vs s are inputs, XJ θP (Dynamic) is the mathematical relationship between active power P and operating power angle θ, XJ VP (Dynamic) is the mathematical relationship between active power P and grid voltage Vs, XJ θQ (Dynamic) is the mathematical relationship between reactive power Q and operating power angle θ, XJ VQ (Dynamic) is the mathematical relationship between reactive power Q and grid voltage Vs.

[0082] Optionally, the calculation formula for calculating the dynamic decoupling coefficient is as follows:

[0083] ;

[0084] Among them, FJ Vθ (Dynamic) is the dynamic decoupling coefficient of active power P and operating voltage V, FJ θV (Dynamic) is the dynamic decoupling coefficient of reactive power Q and operating power angle θ.

[0085] Optionally, the control unit 510 is specifically configured to:

[0086] Construct a fusion decoupling model according to the steady-state decoupling coefficient and the dynamic decoupling coefficient, and perform fusion decoupling control based on the fusion decoupling model. The fusion decoupling model is:

[0087] ;

[0088] Among them, FJ Vθ (Steady state) is the steady-state decoupling coefficient of active power P and operating voltage V, FJ θV (Steady state) is the steady-state decoupling coefficient of reactive power Q and operating power angle θ, FJ Vθ (Dynamic) is the dynamic decoupling coefficient of active power P and operating voltage V, FJ θV (Dynamic) is the dynamic decoupling coefficient of reactive power Q and operating power angle θ, is the power angle generated by the conventional active support control algorithm, is the voltage generated by the conventional active support control algorithm, is the power angle generated by the fusion type additional decoupling control algorithm, is the voltage generated by the fusion type additional decoupling control algorithm.

[0089] The systems, devices, modules or units illustrated in the above embodiments can be specifically implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer, and the specific form of the computer can be a personal computer, a laptop computer, a cellular phone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email receiving and sending device, a game console, a tablet computer, a wearable device, or a combination of any several of these devices.

[0090] In a typical configuration, a computer includes one or more processors (CPUs), an input / output interface, a network interface, and a memory.

[0091] The memory may include non-permanent memory in the computer-readable medium, in the form of random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash memory (flash RAM). The memory is an example of a computer-readable medium.

[0092] The computer-readable medium includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. The information can be computer-readable instructions, data structures, program modules, or other data. Examples of the computer's storage medium include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette tapes, disk storage, quantum memory, graphene-based storage media or other magnetic storage devices, or any other non-transmission media that can be used to store information accessible by a computing device. As defined herein, the computer-readable medium does not include transitory computer-readable media, such as modulated data signals and carrier waves.

[0093] For the computer-readable medium (or, computer-readable storage medium) described above or in any other form, computer instructions can be stored thereon, and when the instructions are executed by the processor, one or more of the above-described embodiments are implemented, thereby implementing the technical solution of the present invention.

[0094] The present invention also provides a computer program, which, when executed by a processor, implements one or more of the above-described embodiments, thereby implementing the technical solution of the present invention. Among them, the computer program can be specifically recorded on the computer-readable medium as described above or in any other form, and the present invention does not limit this.

[0095] It should also be noted that the terms "comprising", "including" or any other variation thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, commodity or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, commodity or device including the said element.

[0096] The specific embodiments of the present invention have been described above. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than in the embodiments and still achieve the desired result. Additionally, the processes depicted in the figures do not necessarily require the particular order or sequential order shown to achieve the desired result. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0097] The terms used in one or more embodiments of the present invention are for the purpose of describing specific embodiments only and are not intended to limit one or more embodiments of the present invention. The singular forms "a", "the" and "said" used in one or more embodiments of the present invention and the appended claims are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0098] It should be understood that although the terms first, second, third, etc. may be used in one or more embodiments of the present invention to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of one or more embodiments of the present invention, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "when" or "upon" or "in response to determining".

[0099] The above are only the preferred embodiments of one or more embodiments of the present invention, and are not intended to limit one or more embodiments of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of one or more embodiments of the present invention shall be included within the scope of protection of one or more embodiments of the present invention.

Claims

1. An active support control method for a network-forming converter based on frequency-voltage coupling, characterized in that The method includes: Obtain the system parameters and operating condition parameters of the network-forming converter for calculating additional control parameters; wherein, the system parameters include: the equivalent voltage VC of the internal AC side of the converter, the equivalent inductance LC of the internal AC side of the converter, the equivalent resistance RC of the internal AC side of the converter, the PI parameters of the active power synchronization control loop, the PI parameters of the AC voltage control loop, the PI parameters of the reactive power synchronization control loop, and the operating condition parameters include: the equivalent voltage V of the AC power grid connected to the converter g , the equivalent inductance L of the AC power grid connected to the converter g , the equivalent resistance Rg of the AC power grid connected to the converter, the active power P exchanged between the converter and the AC power grid, the reactive power Q exchanged between the converter and the AC power grid, the reactive power wg exchanged between the AC power grids, and the power angle θ g , the power angle θ generated by the conventional active support control algorithm 旧 * ; According to the power angle θ between AC power grids g and the power angle θ generated by the conventional active support control algorithm 旧 * Calculate the operating power angle θ of the network-forming converter, and respectively construct the steady-state model and the small-signal stability model of the network-forming converter according to the obtained parameters and the operating power angle θ; Construct an additional steady-state control structure according to the mathematical relationships in the steady-state model, and calculate the steady-state decoupling coefficients in the additional steady-state control structure on the condition that the non-diagonal elements in the steady-state control are zero; Construct an additional dynamic control structure according to the mathematical relationships in the small-signal stability model, and calculate the dynamic decoupling coefficients in the additional dynamic control structure on the condition that the non-diagonal elements in the dynamic control are zero; Perform a fusion decoupling control on the network-forming converter based on the steady-state decoupling coefficients and the dynamic decoupling coefficients.

2. The method according to claim 1, wherein Said according to the power angle θ between AC power grids g and the power angle θ generated by the conventional active support control algorithm 旧 * Calculate the operating power angle θ of the network-forming converter, including: Calculate the power angle θ between AC power grids g and the power angle θ generated by the conventional active support control algorithm 旧 * Take the difference, and use the power angle difference as the operating power angle θ of the network-forming converter.

3. The method according to claim 1, wherein The steady-state model is as follows: ； Among them, the steady-state model takes the operating power angle θ and the grid voltage Vs as inputs, and the active power P and the reactive power Q as outputs. XJ θP XJ(steady state) is the mathematical relationship between the active power P and the operating power angle θ. VP XJ(steady state) is the mathematical relationship between the active power P and the grid voltage Vs. θQ XJ(steady state) is the mathematical relationship between the reactive power Q and the operating power angle θ. VQ XJ(steady state) is the mathematical relationship between the reactive power Q and the grid voltage Vs.

4. The method according to claim 3, characterized in that The calculation formula for calculating the steady-state decoupling coefficients is as follows: ； Among them, FJ Vθ (steady state) is the steady-state decoupling coefficient of the active power P and the operating voltage V, and FJ θV (steady state) is the steady-state decoupling coefficient of the reactive power Q and the operating power angle θ.

5. The method according to claim 1, wherein The small-signal stability model is as follows: ； Among them, with the small-signal increments ∆P of the active power P and ∆Q of the reactive power Q as the outputs, the small-signal increment ∆θ of the operating power angle θ of the grid-forming converter and the small-signal increment ∆V of the grid voltage Vs s are taken as the inputs, and XJ θP (dynamic) is the mathematical relationship between the active power P and the operating power angle θ, and XJ VP (dynamic) is the mathematical relationship between the active power P and the grid voltage Vs, and XJ θQ (dynamic) is the mathematical relationship between the reactive power Q and the operating power angle θ, and XJ VQ (dynamic) is the mathematical relationship between the reactive power Q and the grid voltage Vs.

6. The method according to claim 5, wherein The calculation formula for calculating the dynamic decoupling coefficients is as follows: ； Among them, FJ Vθ (dynamic) is the dynamic decoupling coefficient of the active power P and the operating voltage V, FJ θV (dynamic) is the dynamic decoupling coefficient of the reactive power Q and the operating power angle θ.

7. The method according to claim 1, characterized in that, The performing a fusion decoupling control on the network-forming converter based on the steady-state decoupling coefficients and the dynamic decoupling coefficients includes: Construct a fusion decoupling model according to the steady-state decoupling coefficients and the dynamic decoupling coefficients, and perform a fusion decoupling control based on the fusion decoupling model. The fusion decoupling model is: ； Among them, FJ Vθ (steady state) is the steady-state decoupling coefficient of active power P and operating voltage V, and FJ θV (steady state) is the steady-state decoupling coefficient of reactive power Q and operating power angle θ, and FJ Vθ (dynamic) is the dynamic decoupling coefficient of active power P and operating voltage V, and FJ θV (dynamic) is the dynamic decoupling coefficient of reactive power Q and operating power angle θ, is the power angle generated by the conventional active support control algorithm, is the voltage generated by the conventional active support control algorithm, is the power angle generated by the fusion-type additional decoupling control algorithm, is the voltage generated by the fusion-type additional decoupling control algorithm.

8. An active support control device for a network-forming converter based on frequency-voltage coupling, characterized in that, The device includes: Acquisition unit: acquire the system parameters and operating condition parameters of the network-forming converter for calculating additional control parameters; wherein, the system parameters include: the internal AC side equivalent voltage VC of the converter, the internal AC side equivalent inductance LC of the converter, the internal AC side equivalent resistance RC of the converter, the PI parameters of the active power synchronization control loop, the PI parameters of the AC voltage control loop, the PI parameters of the reactive power synchronization control loop, and the operating condition parameters include: the equivalent voltage V of the AC power grid connected to the converter g , the equivalent inductance L of the AC power grid connected to the converter g , the equivalent resistance Rg of the AC power grid connected to the converter, the exchanged active power P between the converter and the AC power grid, the exchanged reactive power Q between the converter and the AC power grid, the exchanged reactive power wg between the AC power grids, and the power angle θ g , the power angle θ generated by the conventional active support control algorithm 旧 * ; Calculation unit: Based on the power angle θ between AC power grids g and the power angle θ generated by the conventional active support control algorithm 旧 * Calculate the operating power angle θ of the network-forming converter, and respectively construct the steady-state model and small-signal stability model of the network-forming converter according to the obtained parameters and the operating power angle θ; A first construction unit: construct an additional steady-state control structure according to the mathematical relationships in the steady-state model, and calculate the steady-state decoupling coefficients in the additional steady-state control structure on the condition that the non-diagonal elements in the steady-state control are zero; A second construction unit: construct an additional dynamic control structure according to the mathematical relationships in the small-signal stability model, and calculate the dynamic decoupling coefficients in the additional dynamic control structure on the condition that the non-diagonal elements in the dynamic control are zero; A control unit: perform a fusion decoupling control on the network-forming converter based on the steady-state decoupling coefficients and the dynamic decoupling coefficients.

9. An electronic device, characterized in that, It includes: A processor; A memory for storing instructions executable by the processor; Wherein, the processor realizes the steps of the method according to any one of claims 1-7 by running the executable instructions.

10. A computer-readable storage medium having computer instructions stored thereon, characterized in that, When the instructions are executed by the processor, the steps of the method according to any one of claims 1-7 are realized.

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