Virtual synchronous machine grid-connected system fault point identification method and device based on opposite side identification, equipment and medium

Abstract

The invention discloses a virtual synchronous generator grid-connected system fault point identification method, a virtual synchronous generator grid-connected system fault point identification device, virtual synchronous generator grid-connected system fault point identification equipment and a medium based on opposite side identification. Collecting the bus voltage of the grid-connected system at the outlet side of the current converter, the maximum value of the current amplitude after the current converter triggers the current limiting control, and the phase angle and the saturation current angle provided by the VSG, and obtaining the unit reactance value of a wire in the grid-connected system; inputting the bus voltage, the maximum value of the current amplitude after the current converter triggers the current limiting control, and the phase angle and the saturation current angle provided by the VSG into a fault detection model, so that the fault detection model solves the measured reactance and the grounding resistance of the virtual synchronous generator grid-connected system according to the input data; and determining the position of the fault point of the virtual synchronous generator grid-connected system according to the measured reactance and the unit reactance value. By implementing the method, the fault point of the virtual synchronous machine grid-connected system can be quickly and accurately positioned.

Description

Technical Field

[0001] The present invention relates to the field of electric power technology, and in particular to a method, device, equipment and medium for identifying a fault point of a virtual synchronous machine grid-connected system based on opposite-side identification. Background Art

[0002] In the virtual synchronous generator (VSG) grid-connected system, with the rapid development of renewable energy and the large-scale access of distributed power sources, the requirements for the safety and stability of the system are increasing. Under the existing technical conditions, although automated and intelligent monitoring methods are gradually becoming popular, in some cases, manual measurement and calculation are still important means of evaluating the system status. Manual measurement and calculation take a certain amount of time, including data collection, processing, analysis, and calculation steps. In a rapidly changing power system, this delay may result in the inability to capture the dynamic changes of the system in a timely manner, thereby affecting the real-time evaluation of the safety and stability of the system. Summary of the invention

[0003] The present invention provides a method, device, equipment and medium for identifying fault points of a virtual synchronous generator grid-connected system based on opposite-side identification. The method solves the measured reactance through a fault detection model, and obtains the location of the fault point of the virtual synchronous generator grid-connected system based on the measured reactance and the unit reactance value, so as to achieve the purpose of quickly and accurately locating the fault point.

[0004] An embodiment of the present invention provides a method for identifying a fault point of a virtual synchronous machine grid-connected system based on opposite-side identification, comprising:

[0005] When it is determined that a fault occurs in the virtual synchronous generator grid-connected system, the bus voltage at the converter outlet side of the virtual synchronous generator grid-connected system, the maximum current amplitude after the converter triggers the current limiting control, the phase angle and the saturation current angle provided by the VSG are collected, and the unit reactance value of the conductor in the virtual synchronous generator grid-connected system is obtained;

[0006] The bus voltage, the maximum value of the current amplitude after the converter triggers the current limiting control, the phase angle provided by the VSG and the saturation current angle are input into the fault detection model, so that the fault detection model can solve the measured reactance and grounding resistance of the virtual synchronous generator grid-connected system according to the input data; wherein the fault detection model is composed of the operating parameters of the converter in the virtual synchronous generator grid-connected system and the system characteristic parameters of the virtual synchronous generator grid-connected system;

[0007] The location of the fault point of the virtual synchronous generator grid-connected system is determined according to the measured reactance and the unit reactance value.

[0008] Furthermore, the construction process of the fault detection model includes:

[0009] Obtaining operating parameters of the converter in the virtual synchronous generator grid-connected system, system characteristic parameters of the virtual synchronous generator grid-connected system, and a relational expression for characterizing the relationship between the bus voltage and bus current at the converter outlet side in the virtual synchronous generator grid-connected system;

[0010] Performing an imaginary and real part separation operation on the relational expression to obtain a nonlinear equation group for solving the measured reactance;

[0011] The fault detection model is determined according to the operating parameters, the system characteristic parameters and the nonlinear equation group.

[0012] Furthermore, the relational expression for characterizing the relationship between the bus voltage and bus current at the converter outlet side in the virtual synchronous generator grid-connected system is specifically:

[0013]

[0014] In the formula, Represents the voltage phasor at the converter output side; Indicates the current phasor at the converter output side θ c represents the phase angle provided by the VSG, represents the saturation current angle, Represents the maximum current amplitude after the converter triggers the current limiting control; R g Indicates the grounding resistance of the fault point; X q =X t -X p , X q Indicates the line reactance from the system outlet to the fault point, X t represents the transmission line reactance, X p Indicates the measured reactance from the converter outlet to the fault point; X s represents the internal reactance of the system; Represents the system voltage phasor.

[0015] Furthermore, the fault detection model is specifically:

[0016]

[0017] Where U p Indicates the bus voltage at the converter outlet side; R g Indicates the grounding resistance of the fault point; X p Indicates the measured reactance from the converter outlet to the fault point; Represents the maximum current amplitude after the converter triggers the current limiting control; θ crepresents the phase angle provided by VSG; Indicates the saturation current angle; U s Indicates system voltage; X s represents the internal reactance of the system; X t Represents the reactance of the transmission line; δ p Indicates the phase angle of the bus voltage phasor on the converter output side.

[0018] Further, determining the location of the fault point of the virtual synchronous generator grid-connected system according to the measured reactance and the unit reactance value includes:

[0019] Dividing the measured reactance by the unit reactance value to obtain the fault distance;

[0020] The location of the fault point is determined according to the fault distance.

[0021] An embodiment of the present invention further provides a device for identifying a fault point of a virtual synchronous machine grid-connected system based on opposite-side identification, comprising: a data acquisition module, a measured reactance solution module, and a fault point location module;

[0022] The data acquisition module is used to collect the bus voltage at the converter outlet side of the virtual synchronous generator grid-connected system, the maximum value of the current amplitude after the converter triggers the current limiting control, the phase angle and the saturation current angle provided by the VSG, and obtain the unit reactance value of the conductor in the virtual synchronous generator grid-connected system when it is determined that the virtual synchronous generator grid-connected system has a fault;

[0023] The measured reactance solution module is used to input the bus voltage, the maximum value of the current amplitude after the converter triggers the current limiting control, the phase angle provided by the VSG and the saturation current angle into the fault detection model, so that the fault detection model can solve the measured reactance and grounding resistance of the virtual synchronous generator grid-connected system according to the input data; wherein the fault detection model is composed of the operating parameters of the converter in the virtual synchronous generator grid-connected system and the system characteristic parameters of the virtual synchronous generator grid-connected system;

[0024] The fault point locating module is used to determine the location of the fault point of the virtual synchronous generator grid-connected system according to the measured reactance and the unit reactance value.

[0025] Furthermore, the construction process of the fault detection model includes:

[0026] Obtaining operating parameters of the converter in the virtual synchronous generator grid-connected system, system characteristic parameters of the virtual synchronous generator grid-connected system, and a relational expression for characterizing the relationship between the bus voltage and bus current at the converter outlet side in the virtual synchronous generator grid-connected system;

[0027] Performing an imaginary and real part separation operation on the relational expression to obtain a nonlinear equation group for solving the measured reactance;

[0028] The fault detection model is determined according to the operating parameters, the system characteristic parameters and the nonlinear equation group.

[0029] Furthermore, the fault detection model is specifically:

[0030]

[0031] Where U p Indicates the bus voltage at the converter outlet side; R g Indicates the grounding resistance of the fault point; X p Indicates the measured reactance from the converter outlet to the fault point; Represents the maximum current amplitude after the converter triggers the current limiting control; θ c represents the phase angle provided by VSG; Indicates the saturation current angle; U s Indicates system voltage; X s represents the internal reactance of the system; X t Represents the reactance of the transmission line; δ p Indicates the phase angle of the bus voltage phasor on the converter output side.

[0032] The present application also provides a terminal device, including:

[0033] one or more processors;

[0034] A memory, coupled to the processor, for storing one or more programs;

[0035] When the one or more programs are executed by the one or more processors, the one or more processors implement the method for identifying fault points in a virtual synchronous machine grid-connected system based on opposite-side identification as described in the above-mentioned embodiment of the invention.

[0036] The present application also provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the method for identifying a fault point in a virtual synchronous machine grid-connected system based on opposite-side identification as described in the above-mentioned embodiment of the invention is implemented.

[0037] The following beneficial effects are achieved by implementing the present invention:

[0038] The present invention provides a method, device, equipment and medium for identifying fault points of a virtual synchronous generator grid-connected system based on opposite-side identification. The method uses the collected bus voltage and bus current as input and inputs them into a fault detection model, so that the fault detection model solves the measured reactance and grounding resistance based on these input data in combination with internal parameters and algorithms, and then determines the electrical distance between the fault point and the measurement point by measuring the reactance and the unit reactance value, thereby determining the location of the fault point of the virtual synchronous generator grid-connected system; therefore, through the above method, the fault point can be quickly and accurately located, which is of great significance for subsequent fault processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the implementation manner will be briefly introduced below. Obviously, the drawings described below are only some implementation manners of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0040] Figure 1 It is a flowchart of a method for identifying a fault point of a virtual synchronous machine grid-connected system based on opposite-side identification provided by a certain embodiment of the present application;

[0041] Figure 2 It is a schematic diagram of the control structure topology of a virtual synchronous machine grid-connected system provided by a certain embodiment of the present application;

[0042] Figure 3 is a flowchart of building a fault detection model provided by a certain embodiment of the present application;

[0043] Figure 4 It is a calculation flow chart of a method for identifying a fault point of a virtual synchronous machine grid-connected system based on opposite-side identification provided in a certain embodiment of the present application;

[0044] Figure 5 It is a schematic diagram of the geometric spacing between three-phase conductors provided in a certain embodiment of the present application;

[0045] Figure 6 It is a structural schematic diagram of a virtual synchronous machine grid-connected system fault point identification device based on opposite-side identification provided by a certain embodiment of the present application;

[0046] Figure 7 It is a structural diagram of a terminal device provided in a certain embodiment of the present application. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0049] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0050] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0051] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0052] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0053] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0054] See also Figure 1 , is a flow chart of a method for identifying a fault point of a virtual synchronous machine grid-connected system based on opposite-side identification provided by an embodiment of the present invention, comprising:

[0055] S1. When it is determined that a virtual synchronous generator grid-connected system has a fault, the bus voltage at the converter outlet side of the virtual synchronous generator grid-connected system, the maximum current amplitude after the converter triggers current limiting control, the phase angle and saturation current angle provided by the VSG are collected, and the unit reactance value of the conductor in the virtual synchronous generator grid-connected system is obtained.

[0056] S2, inputting the bus voltage, the maximum value of the current amplitude after the converter triggers the current limiting control, the phase angle provided by the VSG and the saturation current angle into the fault detection model, so that the fault detection model can solve the measured reactance and grounding resistance of the virtual synchronous generator grid-connected system according to the input data; wherein the fault detection model is composed of the operating parameters of the converter in the virtual synchronous generator grid-connected system and the system characteristic parameters of the virtual synchronous generator grid-connected system;

[0057] In a preferred embodiment, the process of constructing the fault detection model includes:

[0058] Obtaining operating parameters of the converter in the virtual synchronous generator grid-connected system, system characteristic parameters of the virtual synchronous generator grid-connected system, and a relational expression for characterizing the relationship between the bus voltage and bus current at the converter outlet side in the virtual synchronous generator grid-connected system;

[0059] Performing an imaginary and real part separation operation on the relational expression to obtain a nonlinear equation group for solving the measured reactance;

[0060] Determining the fault detection model according to the operating parameters, the system characteristic parameters and the nonlinear equation group;

[0061] See also Figure 2 , is a schematic diagram of a control structure topology of a virtual synchronous machine grid-connected system provided in a certain embodiment of the present application;

[0062] Figure 3 It is a flowchart of a fault detection model construction process provided by a certain embodiment of the present application. Specifically, the relational expression for characterizing the relationship between the bus voltage and the bus current at the converter outlet side in the virtual synchronous generator grid-connected system is obtained by a circuit equation after a fault occurs in the transmission line of the virtual synchronous generator grid-connected system and current is limited;

[0063] Ignoring the transmission line resistance, the circuit equation after the transmission line of the virtual synchronous generator grid-connected system fails and triggers the overcurrent control of the current limiter can be written as:

[0064]

[0065] In the formula, is the voltage phasor at the converter outlet side; is the system voltage phasor; is the voltage phasor at the fault point; R g is the grounding resistance of the fault point; X p is the measured reactance from the converter outlet to the fault point; X q is the line reactance from the system side outlet to the fault point; X s is the internal reactance of the system; is the current phasor at the converter output side; is the current phasor at the system side outlet; is the maximum current amplitude after the converter triggers the current limiting control; θ c The phase angle provided for VSG; is the saturation current angle.

[0066] Then, in order to eliminate other variables in formula (1), Substitution In, can be obtained Then Substitution Solved

[0067] By eliminating the variables above, we get formula (2), which is as follows:

[0068]

[0069] Further elimination of variables The relational expression for characterizing the relationship between the bus voltage and bus current at the converter outlet side in the virtual synchronous generator grid-connected system is obtained, namely, equation (3);

[0070] In a preferred embodiment, the relational expression for characterizing the relationship between the bus voltage and the bus current at the converter outlet side in the virtual synchronous generator grid-connected system is specifically:

[0071]

[0072] In the formula, Represents the voltage phasor at the converter output side; Indicates the current phasor at the converter output side θ c represents the phase angle provided by the VSG, represents the saturation current angle, Represents the maximum current amplitude after the converter triggers the current limiting control; R g Indicates the grounding resistance of the fault point; X q =X t -X p , X q Indicates the line reactance from the system outlet to the fault point, X t represents the transmission line reactance, X p Indicates the measured reactance from the converter outlet to the fault point; X s represents the internal reactance of the system; Represents the system voltage phasor.

[0073] Schematically, the imaginary and real part separation operation is performed on the relational expression;

[0074] Specifically, Substituting into formula (3), and separating the imaginary and real parts of the relational expression obtained by formula (3), we can get formula (4), the specific expression is as follows:

[0075]

[0076] Simplifying formula (4), we get formula (5), the specific expression is as follows:

[0077]

[0078] Then, based on the acquired operating parameters of the converter in the virtual synchronous generator grid-connected system and the system characteristic parameters of the virtual synchronous generator grid-connected system, a fault detection model is constructed, that is, formula (6);

[0079] Specifically, the operating parameters include the phase angle δ of the voltage phasor at the converter outlet side p ; The system characteristic parameters include system voltage U s 、The internal reactance of the system X s , Transmission line reactance X t ;

[0080] Among them, U s and X s By identifying the opposite side information, the transmission line reactance is Xt =X p +X q , by changing X q Represented as X t -X p , and because X t is a known quantity, so the unknown quantity X q Eliminate, for the reactance, only X remains p An unknown quantity to be determined;

[0081] In a preferred embodiment, the fault detection model is specifically:

[0082]

[0083] Where U p Indicates the bus voltage at the converter outlet side; R g Indicates the grounding resistance of the fault point; X p Indicates the measured reactance from the converter outlet to the fault point; Represents the maximum current amplitude after the converter triggers the current limiting control; θ c represents the phase angle provided by VSG; Indicates the saturation current angle; U s Indicates system voltage; X s represents the internal reactance of the system; X t Represents the reactance of the transmission line; δ p Represents the phase angle of the bus voltage phasor at the converter outlet side;

[0084] Specifically, see Figure 4 , the bus voltage, the maximum value of the current amplitude after the converter triggers the current limiting control, the phase angle provided by the VSG and the saturation current angle are input into the fault detection model, so that the fault detection model can solve the measured reactance and grounding resistance of the virtual synchronous generator grid-connected system based on the input data and the known quantities in the fault detection model.

[0085] S3. Determine the location of the fault point of the virtual synchronous generator grid-connected system according to the measured reactance and the unit reactance value;

[0086] In a preferred embodiment, determining the location of the fault point of the virtual synchronous generator grid-connected system according to the measured reactance and the unit reactance value includes:

[0087] Dividing the measured reactance by the unit reactance value to obtain the fault distance;

[0088] Determine the location of the fault point according to the fault distance;

[0089] Specifically, the unit reactance value is a known quantity, and the formula for solving the fault distance is as follows:

[0090]

[0091] In the formula, X p It represents the measured reactance from the converter outlet to the fault point; x represents the unit reactance value of the conductor;

[0092] See also Figure 5 , is a schematic diagram of the geometric spacing between three-phase conductors, and the specific expression of the unit reactance value x of the conductor is as follows:

[0093]

[0094] Where D m Indicates the geometric spacing between three-phase conductors.

[0095] See also Figure 6 , is a virtual synchronous machine grid-connected system fault point identification device based on opposite-side identification provided by an embodiment of the present invention, comprising: a data acquisition module, a measurement reactance solution module and a fault point location module;

[0096] The data acquisition module is used to collect the bus voltage at the converter outlet side of the virtual synchronous generator grid-connected system, the maximum value of the current amplitude after the converter triggers the current limiting control, the phase angle and the saturation current angle provided by the VSG, and obtain the unit reactance value of the conductor in the virtual synchronous generator grid-connected system when it is determined that the virtual synchronous generator grid-connected system has a fault;

[0097] The measured reactance solution module is used to input the bus voltage, the maximum value of the current amplitude after the converter triggers the current limiting control, the phase angle provided by the VSG and the saturation current angle into the fault detection model, so that the fault detection model can solve the measured reactance and grounding resistance of the virtual synchronous generator grid-connected system according to the input data; wherein the fault detection model is composed of the operating parameters of the converter in the virtual synchronous generator grid-connected system and the system characteristic parameters of the virtual synchronous generator grid-connected system;

[0098] The fault point locating module is used to determine the location of the fault point of the virtual synchronous generator grid-connected system according to the measured reactance and the unit reactance value.

[0099] In a preferred embodiment, the process of constructing the fault detection model includes:

[0100] Obtaining operating parameters of the converter in the virtual synchronous generator grid-connected system, system characteristic parameters of the virtual synchronous generator grid-connected system, and a relational expression for characterizing the relationship between the bus voltage and bus current at the converter outlet side in the virtual synchronous generator grid-connected system;

[0101] Performing an imaginary and real part separation operation on the relational expression to obtain a nonlinear equation group for solving the measured reactance;

[0102] The fault detection model is determined according to the operating parameters, the system characteristic parameters and the nonlinear equation group.

[0103] In a preferred embodiment, the fault detection model is specifically:

[0104]

[0105] Where U p Indicates the bus voltage at the converter outlet side; R g Indicates the grounding resistance of the fault point; X p Indicates the measured reactance from the converter outlet to the fault point; Represents the maximum current amplitude after the converter triggers the current limiting control; θ c represents the phase angle provided by VSG; Indicates the saturation current angle; U s Indicates system voltage; X s represents the internal reactance of the system; X t Represents the reactance of the transmission line; δ p Indicates the phase angle of the bus voltage phasor on the converter output side.

[0106] See also Figure 7 , a certain embodiment of the present application further provides a terminal device, including:

[0107] one or more processors;

[0108] A memory, coupled to the processor, for storing one or more programs;

[0109] When the one or more programs are executed by the one or more processors, the one or more processors implement the method for identifying a fault point in a virtual synchronous machine grid-connected system based on opposite-side identification as described above.

[0110] The processor is used to control the overall operation of the terminal device to complete all or part of the steps of the above-mentioned method for identifying the fault point of the virtual synchronous machine grid-connected system based on the opposite side identification. The memory is used to store various types of data to support the operation of the terminal device, and these data may include, for example, instructions for any application or method used to operate on the terminal device, and data related to the application. The memory can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (Static Random Access Memory, referred to as SRAM), electrically erasable programmable read-only memory (Electrically Erasable Programmable Read-Only Memory, referred to as EEPROM), erasable programmable read-only memory (Erasable Programmable Read-Only Memory, referred to as EPROM), programmable read-only memory (Programmable Read-Only Memory, referred to as PROM), read-only memory (Read-Only Memory, referred to as ROM), magnetic memory, flash memory, disk or optical disk.

[0111] In an exemplary embodiment, the terminal device can be implemented by one or more application specific integrated circuits (ASIC), digital signal processors (DSP), digital signal processing devices (DSPD), programmable logic devices (PLD), field programmable gate arrays (FPGA), controllers, microcontrollers, microprocessors or other electronic components, and is used to execute the virtual synchronous machine grid-connected system fault point identification method based on opposite side identification as described in any of the above embodiments, and achieve the technical effect consistent with the above method.

[0112] In another exemplary embodiment, a computer-readable storage medium including a computer program is also provided, and when the computer program is executed by a processor, the steps of the method for identifying a fault point of a virtual synchronous machine grid-connected system based on opposite-side identification as described in any of the above embodiments are implemented. For example, the computer-readable storage medium may be the above-mentioned memory including the computer program, and the above-mentioned computer program may be executed by a processor of a terminal device to complete the method for identifying a fault point of a virtual synchronous machine grid-connected system based on opposite-side identification as described in any of the above embodiments, and achieve the technical effect consistent with the above-mentioned method.

[0113] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for identifying fault points in a virtual synchronous machine grid-connected system based on opposite-side identification, characterized in that: include: When it is determined that a fault occurs in the virtual synchronous generator grid-connected system, the bus voltage at the converter outlet side of the virtual synchronous generator grid-connected system, the maximum current amplitude after the converter triggers the current limiting control, the phase angle and the saturation current angle provided by the VSG are collected, and the unit reactance value of the conductor in the virtual synchronous generator grid-connected system is obtained; The bus voltage, the maximum value of the current amplitude after the converter triggers the current limiting control, the phase angle provided by the VSG and the saturation current angle are input into the fault detection model, so that the fault detection model can solve the measured reactance and grounding resistance of the virtual synchronous generator grid-connected system according to the input data; wherein the fault detection model is composed of the operating parameters of the converter in the virtual synchronous generator grid-connected system and the system characteristic parameters of the virtual synchronous generator grid-connected system; The location of the fault point of the virtual synchronous generator grid-connected system is determined according to the measured reactance and the unit reactance value.

2. The method for identifying fault points in a virtual synchronous machine grid-connected system based on opposite-side identification according to claim 1, characterized in that: The construction process of the fault detection model includes: Obtaining operating parameters of the converter in the virtual synchronous generator grid-connected system, system characteristic parameters of the virtual synchronous generator grid-connected system, and a relational expression for characterizing the relationship between the bus voltage and bus current at the converter outlet side in the virtual synchronous generator grid-connected system; Performing an imaginary and real part separation operation on the relational expression to obtain a nonlinear equation group for solving the measured reactance; The fault detection model is determined according to the operating parameters, the system characteristic parameters and the nonlinear equation group.

3. The method for identifying fault points in a virtual synchronous machine grid-connected system based on opposite-side identification according to claim 2, characterized in that: The relational expression for characterizing the relationship between the bus voltage and bus current at the converter outlet side in the virtual synchronous generator grid-connected system is specifically: In the formula, Represents the voltage phasor at the converter output side; Indicates the current phasor at the converter output side θ c represents the phase angle provided by the VSG, represents the saturation current angle, Represents the maximum current amplitude after the converter triggers the current limiting control; R g Indicates the grounding resistance of the fault point; X q =X t -X p , X q Indicates the line reactance from the system outlet to the fault point, X t represents the transmission line reactance, X p Indicates the measured reactance from the converter outlet to the fault point; X s represents the internal reactance of the system; Represents the system voltage phasor.

4. The method for identifying fault points in a virtual synchronous machine grid-connected system based on opposite-side identification according to claim 2, characterized in that: The fault detection model is specifically: Where U p Indicates the bus voltage at the converter outlet side; R g Indicates the grounding resistance of the fault point; X p Indicates the measured reactance from the converter outlet to the fault point; Represents the maximum current amplitude after the converter triggers the current limiting control; θ c represents the phase angle provided by VSG; represents the saturation current angle; U s Indicates system voltage; X s represents the internal reactance of the system; X t Represents the reactance of the transmission line; δ p Indicates the phase angle of the bus voltage phasor on the converter output side.

5. The method for identifying fault points of a virtual synchronous machine grid-connected system based on opposite-side identification according to claim 1, characterized in that: The determining the location of the fault point of the virtual synchronous generator grid-connected system according to the measured reactance and the unit reactance value comprises: Dividing the measured reactance by the unit reactance value to obtain the fault distance; The location of the fault point is determined according to the fault distance.

6. A device for identifying fault points in a virtual synchronous machine grid-connected system based on opposite-side identification, characterized in that: include: Data acquisition module, measured reactance solution module and fault point location module; The data acquisition module is used to collect the bus voltage at the converter outlet side of the virtual synchronous generator grid-connected system, the maximum value of the current amplitude after the converter triggers the current limiting control, the phase angle and the saturation current angle provided by the VSG, and obtain the unit reactance value of the conductor in the virtual synchronous generator grid-connected system when it is determined that the virtual synchronous generator grid-connected system has a fault; The measured reactance solution module is used to input the bus voltage, the maximum value of the current amplitude after the converter triggers the current limiting control, the phase angle provided by the VSG and the saturation current angle into the fault detection model, so that the fault detection model can solve the measured reactance and grounding resistance of the virtual synchronous generator grid-connected system according to the input data; wherein the fault detection model is composed of the operating parameters of the converter in the virtual synchronous generator grid-connected system and the system characteristic parameters of the virtual synchronous generator grid-connected system; The fault point locating module is used to determine the location of the fault point of the virtual synchronous generator grid-connected system according to the measured reactance and the unit reactance value.

7. The device for identifying fault points of a virtual synchronous machine grid-connected system based on opposite-side identification according to claim 6, characterized in that: The construction process of the fault detection model includes: Obtaining operating parameters of the converter in the virtual synchronous generator grid-connected system, system characteristic parameters of the virtual synchronous generator grid-connected system, and a relational expression for characterizing the relationship between the bus voltage and bus current at the converter outlet side in the virtual synchronous generator grid-connected system; Performing an imaginary and real part separation operation on the relational expression to obtain a nonlinear equation group for solving the measured reactance; The fault detection model is determined according to the operating parameters, the system characteristic parameters and the nonlinear equation group.

8. The device for identifying fault points of a virtual synchronous machine grid-connected system based on opposite-side identification according to claim 7, characterized in that: The fault detection model is specifically: Where U p Indicates the bus voltage at the converter outlet side; R g Indicates the grounding resistance of the fault point; X p Indicates the measured reactance from the converter outlet to the fault point; Represents the maximum current amplitude after the converter triggers the current limiting control; θ c represents the phase angle provided by VSG; represents the saturation current angle; U s Indicates system voltage; X s represents the internal reactance of the system; X t Represents the reactance of the transmission line; δ p Indicates the phase angle of the bus voltage phasor on the converter output side.

9. A device, characterized in that: include: one or more processors; A memory, coupled to the processor, for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the method for identifying fault points in a virtual synchronous machine grid-connected system based on opposite-side identification as described in any one of claims 1 to 5.

10. A medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for identifying a fault point in a virtual synchronous machine grid-connected system based on opposite-side identification as described in any one of claims 1 to 5 is implemented.

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