Method for quickly identifying sequence parameters of double-circuit operation power transmission line

Abstract

The invention relates to the field of power systems, and discloses a method for quickly identifying sequence parameters of a double-circuit operation power transmission line. The method comprises the following steps: acquiring input data, wherein the input data comprises a double-circuit operation power transmission line structure and component parameters; the method comprises the following steps: establishing a line model of a first single-circuit operation power transmission line, calculating an impedance matrix of the first single-circuit operation power transmission line based on input data to obtain a first self-sequence impedance, and performing the same calculation on a second single-circuit operation power transmission line symmetrical to the first single-circuit operation power transmission line to obtain a second self-sequence impedance. Building a line model of the double-circuit operation power transmission line, calculating an all-phase impedance matrix and an all-phase admittance matrix corresponding to six-phase wires of the double-circuit operation power transmission line based on the input data, and obtaining zero-sequence mutual capacitance and zero-sequence mutual impedance. The impedance matrix and the admittance matrix are transformed, self-sequence impedance is combined, self-sequence parameters and mutual-sequence parameters of the double-circuit operation power transmission line are obtained, the self-sequence impedance of the double-circuit operation power transmission line is the same as that of the single-circuit operation power transmission line, and the mutual-sequence parameters are only decoupled from a zero-sequence component, a positive-sequence component and a negative-sequence component. Through the method, the sequence parameters of the double-circuit transmission line can be quickly and accurately identified, signal test or long-time simulation does not need to be applied, and the method has the advantages of high efficiency and accuracy.

Description

Technical Field

[0001] The present application relates to the field of electric power systems, and in particular to a method for rapidly identifying sequence parameters of a double-circuit transmission line. Background Art

[0002] This section is intended to provide a background or context for the embodiments of the present application as stated in the claims. The contents in this section are for reference only and do not constitute an admission or confirmation that they are prior art that has been disclosed.

[0003] With the rapid development of modern power grids and the continuous growth of electricity demand, high-voltage transmission channel resources are becoming increasingly scarce. In order to achieve greater transmission capacity on limited channels, modern power grids are increasingly adopting double-circuit lines on the same tower when planning and building high-voltage transmission lines. This line form can not only make full use of limited corridor resources, but also effectively improve the transmission capacity of the line. It is a key solution to cope with the high load demand of future power grids.

[0004] However, due to the mutual influence of the two adjacent circuits, the impedance, admittance and inter-circuit coupling parameters of the double-circuit line become more complicated. Before the transmission line is put into operation, the operation department usually needs the design department to provide the theoretically calculated line sequence parameters so that they can be verified and measured after the construction is completed. Accurate sequence parameters can help the operation department better understand the electrical characteristics and operating status of the double-circuit line, so as to carry out effective monitoring and maintenance and ensure the stability and safety of the power system.

[0005] In the existing technology, although the 6×6 impedance matrix including the inter-circuit coupling can be calculated by inputting multiple parameters such as tower shape, conductor parameters, sag, span, and call height, with the help of electromagnetic transient program (EMTP) and electromagnetic transient digital calculation (EMTDC) software, these software cannot directly provide the sequence parameters and inter-circuit mutual parameters of double-circuit lines. Therefore, how to extract effective sequence parameters and inter-circuit mutual parameters from the complex impedance matrix has become a major problem in the design and operation of power systems. Summary of the invention

[0006] The purpose of the present application is to provide a method for quickly identifying the sequence parameters of a double-circuit transmission line, which can quickly and accurately identify the sequence parameters of a double-circuit transmission line without applying signal testing or long-term simulation, and has the advantages of high efficiency and accuracy.

[0007] The present application discloses a method for quickly identifying sequence parameters of a double-circuit transmission line, comprising:

[0008] Step S1. Obtaining input data, wherein the input data includes double-circuit transmission line structure and component parameters;

[0009] Step S2. construct a line model of a first single-loop transmission line, calculate the impedance matrix of the first single-loop transmission line based on the input data, obtain a first self-sequence impedance, and perform the same calculation on a second single-loop transmission line symmetrical to the first single-loop transmission line to obtain a second self-sequence impedance;

[0010] Step S3. construct a line model of the double-circuit transmission line, and based on the input data, calculate the full-phase impedance matrix and full-phase admittance matrix corresponding to the six-phase conductors of the double-circuit transmission line to obtain zero-sequence mutual capacitance and zero-sequence mutual impedance;

[0011] Step S4. Transform the impedance matrix and the admittance matrix, and combine them with the self-sequence impedance to obtain the self-sequence parameters and mutual-sequence parameters of the double-circuit transmission line. The self-sequence impedance of the double-circuit transmission line is the same as that of the single-circuit transmission line, and the mutual-sequence parameter has only a zero-sequence component, and the positive-sequence component and the negative-sequence component are decoupled.

[0012] In a preferred embodiment, obtaining input data further comprises:

[0013] Obtaining the parameters of the conductor and ground wire used in the double-circuit transmission line, including the number of splits of the split conductor, the split spacing, the number of aluminum steel strands in each sub-conductor, the radius, the DC resistance of the conductor, and the sag of the conductor;

[0014] Obtaining the structural parameters of the double-circuit transmission line tower and insulator, and calculating the spatial position of each phase conductor suspension;

[0015] The transposition information between the conductors of the double-circuit transmission line is obtained.

[0016] In a preferred example, the construction of the line model of the first single-circuit transmission line further includes:

[0017] Calculate the 3*3 impedance matrix corresponding to the 3-phase conductors of the first single-circuit transmission line and the 3*3 impedance matrix corresponding to the 3-phase conductors of the second single-circuit transmission line, by

[0018]

[0019] Calculate Z seq The first self-sequence impedance Z of the first single-circuit transmission line is obtained by 01 , Z +1 , Z -1 , and the second self-sequence impedance Z of the second single-circuit transmission line 02 , Z +2 , Z -2 ;

[0020] If the first single-circuit transmission line is symmetrical to the second single-circuit transmission line, the parameter of the first self-sequence impedance is equal to the parameter of the second self-sequence impedance.

[0021] In a preferred example, the line model of the double-circuit transmission line further includes:

[0022] Calculate the 6*6 full-phase impedance matrix corresponding to the 6-phase conductors of the double-circuit transmission line, and divide the full-phase impedance matrix into 4 blocks:

[0023]

[0024] Among them, the non-diagonal blocks The 9 elements in are approximately equal, that is,

[0025] The zero-sequence mutual impedance of the double-circuit transmission line is 3 times the arithmetic mean of the 9 elements in

[0026]

[0027] In a preferred example, the line model of the double-circuit transmission line further includes:

[0028] Calculate the 6*6 full-phase admittance matrix corresponding to the 6-phase conductors of the double-circuit transmission line, and divide the full-phase admittance matrix into 4 blocks:

[0029]

[0030] The zero-sequence mutual admittance of the double-circuit transmission line is 3 times the arithmetic mean of the 9 elements in

[0031]

[0032] in,

[0033] According to the relationship between capacitance and susceptance, the zero-sequence mutual capacitance of the double-circuit transmission line is calculated:

[0034]

[0035] In a preferred example, the transforming of the impedance matrix and the admittance matrix to obtain the self-sequence parameters and the mutual-sequence parameters of the double-circuit transmission line further comprises:

[0036] Extracting off-diagonal matrix elements from the full-phase impedance matrix and the full-phase admittance matrix;

[0037] Calculating mutual order parameters based on the extracted off-diagonal array elements;

[0038]

[0039] Where T is a block diagonal matrix;

[0040]

[0041] According to the calculation results, the mutual sequence parameters of the double-circuit transmission line are output.

[0042] In a preferred example, the double-circuit transmission line consists of two independent single-circuit lines, namely a first single-circuit transmission line and a second single-circuit transmission line, and the self-impedance of each single-circuit transmission line is not affected by the other single-circuit transmission line.

[0043] In a preferred example, the positive sequence parameter and the negative sequence parameter only have self-sequence parameters but no mutual sequence parameters.

[0044] The present application also discloses a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, the steps in the method described above are implemented.

[0045] The present application also discloses a computer program product, comprising computer executable instructions, which can implement the steps in the method described above when executed by a processor.

[0046] In the implementation manner of the present application, when calculating the sequence parameters of a double-circuit transmission line, the positive and negative sequence parameters and the zero-sequence parameters are solved separately based on the principle of decoupling of positive and negative sequence self-impedance and mutual impedance. The positive and negative sequence parameters only have self-sequence parameters but no mutual-sequence parameters, which can be directly obtained by solving the impedance matrix according to the single-circuit line model; the zero-sequence self-parameters are obtained by solving the single-circuit line model, and the zero-sequence mutual parameters can be calculated by the elements of the non-diagonal block matrix of the full-phase impedance matrix and the full-phase admittance matrix of the double-circuit line. This method does not require signal testing on the line port, nor does it require running the simulation program for a long time, and can quickly obtain accurate sequence parameter identification results according to the analytical solutions of the impedance matrix and the admittance matrix.

[0047] Each technical feature disclosed in the above invention content, each technical feature disclosed in each implementation mode and example below, and each technical feature disclosed in the accompanying drawings can be freely combined with each other to form various new technical solutions (these technical solutions should be deemed to have been recorded in this specification), unless such combination of technical features is technically infeasible. For example, in one example, feature A+B+C is disclosed, and in another example, feature A+B+D+E is disclosed, and features C and D are equivalent technical means that play the same role. Technically, only one of them can be used, and it is impossible to use them at the same time. Feature E can be combined with feature C technically. Then, the solution of A+B+C+D should not be deemed to have been recorded because it is technically infeasible, while the solution of A+B+C+E should be deemed to have been recorded. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a flowchart of a method for quickly identifying sequence parameters of a double-circuit transmission line according to an embodiment of the present application.

[0049] Figure 2 It is a schematic diagram of an electrical model of a double-circuit transmission line according to an embodiment of the present application. DETAILED DESCRIPTION

[0050] In the following description, many technical details are provided to help readers better understand the present application. However, those skilled in the art can understand that the technical solution claimed in the present application can be implemented even without these technical details and various changes and modifications based on the following embodiments.

[0051] Description of some concepts:

[0052] Full-phase impedance matrix: an impedance matrix containing all phases of a double-circuit line, whose diagonal elements are self-impedances and non-diagonal elements are mutual impedances between phases.

[0053] All-phase admittance matrix: an admittance matrix containing all phases of a double-circuit line, whose diagonal elements are self-admittances and non-diagonal elements are mutual admittances between phases.

[0054] Sequence parameters of transmission lines: refers to a set of parameters that decompose voltage and current into different symmetrical components (sequence components) when analyzing transmission lines in power systems, thereby simplifying the analysis process. Sequence parameters are important parameters that describe the electrical characteristics (such as impedance, conductance, and admittance) of transmission lines under positive sequence, negative sequence, and zero sequence conditions. The application of sequence parameters allows complex three-phase systems to be decomposed into independent single-phase loops, which is convenient for analysis and calculation.

[0055] Self-sequence parameters of the transmission line: parameters in the sequence parameters that are only related to the current loop line.

[0056] Mutual sequence parameters of transmission lines: sequence parameters that characterize the relationship between the line of this loop and another loop line.

[0057] The innovative features of this application are briefly described below:

[0058] The present application can directly extract effective sequence parameters and mutual parameters between loops, mainly because the positive-sequence and negative-sequence impedances are decoupled, and there are no mutual parameters between loops (that is, only self-sequence impedances exist in the positive-sequence and negative-sequence components), and the zero-sequence component has a coupling characteristic between loops (mutual parameters). This coupling is extracted and calculated through the non-diagonal block elements of the full-phase impedance matrix and the admittance matrix. Therefore, the present application processes the positive and negative sequence parameters and the zero-sequence parameters separately, and the positive and negative sequence parameters are directly calculated using the single-loop line model. The zero-sequence mutual parameters are calculated through the non-diagonal block elements of the full-phase impedance matrix and the admittance matrix of the double-loop line, avoiding mutual interference between sequence components and achieving efficient and accurate extraction. The present application adopts the analytical solution of the full-phase impedance matrix (6×6) and the admittance matrix, combined with the symmetric component transformation, to quickly obtain effective sequence parameters and mutual parameters between loops. Unlike the prior art, the present application does not need to apply actual signals or power to the transmission line port, nor does it need to repeatedly perform simulation tests, and the required parameters can be quickly obtained directly based on the analytical solution.

[0059] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below in conjunction with the accompanying drawings.

[0060] The first embodiment of the present application relates to a method for quickly identifying sequence parameters of a double-circuit transmission line, the process of which is as follows: Figure 1 As shown, the method comprises the following steps:

[0061] Step S1. Obtain input data, the input data including double-circuit transmission line structure and component parameters;

[0062] Step S2. Build a line model of the first single-loop transmission line, calculate the impedance matrix of the first single-loop transmission line based on the input data, obtain the first self-sequence impedance, perform the same calculation on the second single-loop transmission line symmetrical to the first single-loop transmission line, and obtain the second self-sequence impedance;

[0063] Step S3. Build a line model of a double-circuit transmission line, calculate the full-phase impedance matrix and full-phase admittance matrix corresponding to the six-phase conductors of the double-circuit transmission line based on the input data, and obtain the zero-sequence mutual capacitance and zero-sequence mutual impedance;

[0064] Step S4. Transform the impedance matrix and the admittance matrix, and combine them with the self-sequence impedance to obtain the self-sequence parameters and mutual-sequence parameters of the double-circuit transmission line. The self-sequence impedance of the double-circuit transmission line is the same as that of the single-circuit transmission line, and the mutual-sequence parameter has only a zero-sequence component, and the positive-sequence component and the negative-sequence component are decoupled.

[0065] In an optional embodiment, step S1 may further include:

[0066] Obtain the parameters of the conductor and ground wire used in the double-circuit transmission line, including the number of splits of the split conductor, the split spacing, the number of aluminum steel strands in each sub-conductor, the radius, the DC resistance of the conductor, and the sag of the conductor;

[0067] Obtain the structural parameters of the double-circuit transmission line towers and insulators, and calculate the spatial position of each phase conductor suspension;

[0068] Obtain the transposition information between the conductors of the double-circuit transmission line.

[0069] In an optional embodiment, step S2 may further include:

[0070] Calculate the 3*3 impedance matrix corresponding to the 3-phase conductors of the first single-circuit transmission line and the 3*3 impedance matrix corresponding to the 3-phase conductors of the second single-circuit transmission line, through

[0071]

[0072] Calculate Z seq The first self-sequence impedance Z of the first single-circuit transmission line is obtained by 01 , Z +1 , Z -1 , and the second self-sequence impedance Z of the second single-circuit transmission line 02 , Z +2 , Z -2 ;

[0073] If the first single-circuit transmission line is symmetrical to the second single-circuit transmission line, the parameter of the first self-sequence impedance is equal to the parameter of the second self-sequence impedance.

[0074] In an optional embodiment, step S3 may further include:

[0075] Calculate the 6*6 full-phase impedance matrix corresponding to the 6-phase conductors of the double-circuit transmission line, and divide the full-phase impedance matrix into 4 blocks:

[0076]

[0077] Among them, the non-diagonal blocks The 9 elements in are approximately equal, that is,

[0078] The zero-sequence mutual impedance of a double-circuit transmission line is 3 times the arithmetic mean of the 9 elements in

[0079]

[0080] In an optional embodiment, step S3 may further include:

[0081] Calculate the 6*6 full-phase admittance matrix corresponding to the 6-phase conductors of the double-circuit transmission line, and divide the full-phase admittance matrix into 4 blocks:

[0082]

[0083] The zero sequence mutual current of double-circuit transmission lines is 3 times the arithmetic mean of the 9 elements in

[0084]

[0085] in,

[0086] According to the relationship between capacitance and susceptance, the zero-sequence mutual capacitance of double-circuit transmission lines is calculated:

[0087]

[0088] Figure 2 The figure shows a schematic diagram of the electrical model of a double-circuit transmission line. Due to the physical proximity of the double-circuit transmission lines, there are significant electric and magnetic field coupling effects between the lines, namely mutual inductance and mutual capacitance, which together determine the impedance and admittance characteristics of the double-circuit line. The coupling effect between the lines is quantified by the full-phase impedance matrix and full-phase admittance matrix as described above, thereby improving the accuracy of the electrical performance analysis of the double-circuit line.

[0089] In an optional embodiment, step S4 may further include:

[0090] Extracting off-diagonal elements from the full-phase impedance matrix and the full-phase admittance matrix;

[0091] Calculate mutual order parameters based on the extracted off-diagonal matrix elements;

[0092]

[0093] Where T is a block diagonal matrix;

[0094]

[0095] According to the calculation results, the mutual sequence parameters of the double-circuit transmission line are output.

[0096] In an optional embodiment, the double-circuit transmission line is composed of two independent single-circuit lines, namely a first single-circuit transmission line and a second single-circuit transmission line, and the self-impedance of each single-circuit transmission line is not affected by the other single-circuit transmission line.

[0097] In an optional embodiment, the positive sequence parameters and the negative sequence parameters only have self-sequence parameters but no mutual sequence parameters.

[0098] In order to better understand the technical solution of the present application, a specific example is provided below for illustration. The details listed in the example are mainly for ease of understanding and are not intended to limit the scope of protection of the present application.

[0099] The present invention provides a method for quickly identifying sequence parameters of a double-circuit transmission line, which mainly includes the following steps: obtaining input data, building a single-circuit line model to calculate self-sequence impedance, building a double-circuit line model to calculate the full-phase impedance matrix and admittance matrix, and extracting mutual sequence parameters through matrix transformation, etc. The following will describe in detail the technical details and steps used in the implementation process according to the technical content of the present invention.

[0100] First, all the structural and component parameters related to the double-circuit transmission line are obtained as the basis for subsequent modeling and calculation. These input data include but are not limited to: the parameters of the conductor and ground wire: including the number of splits of the split conductor, the split spacing, the number of aluminum steel strands of each sub-conductor, the radius, the DC resistance of the conductor, the sag of the conductor, etc.; the structural parameters of the tower and insulator of the transmission line: including the height, material, structural type, location and structure of the tower; the suspension space position of each phase conductor: according to the structural parameters of the tower and insulator, the suspension position of each phase conductor is calculated so as to consider the spatial layout of the line in the calculation; the transposition information between conductors: collect the transposition information of the line.

[0101] Based on the input data obtained previously, an independent single-circuit line model is first established for each single-circuit line. In the line sequence parameters of the double-circuit transmission line operation, the self-impedance of each line is not affected by the other line, so it can be calculated and extracted according to the matrix of the single-circuit line. In this model, the electrical behavior of each single-circuit line is described by the mutual relationship and impedance matrix of the three-phase conductors. Through the EMTDC program or similar calculation tools, based on the conductor parameters and geometric configuration of the single-circuit line, the 3×3 impedance matrix corresponding to the three-phase conductors of each line is calculated. According to this matrix, the self-sequence impedance is calculated using the following formula:

[0102]

[0103] Through matrix transformation, the three elements of the self-sequence impedance are obtained, namely, the first self-sequence impedance Z of the first single-loop line 01 , Z +1 , Z -1 and the second self-sequence impedance Z of the second single-circuit line 02 , Z +2 , Z -2 , if the first circuit is symmetrical to the second circuit, the self-sequence impedance obtained will be equal.

[0104] Based on the single-circuit line, a double-circuit transmission line model is constructed. The double-circuit line consists of two circuits, so the electromagnetic coupling between the two circuits needs to be considered, and the full-phase impedance matrix and full-phase admittance matrix of the 6-phase conductors are established.

[0105] Using the structural parameters and conductor parameters in the input data, the full-phase impedance matrix corresponding to the 6-phase conductors of the double-circuit line is calculated. This matrix is ​​a 6×6 matrix, whose elements include the impedance values ​​between different phases of the double-circuit line. The matrix is ​​divided into 4 blocks, where the elements Z of the non-diagonal blocks are 12 and Z 21 The 9 elements of are approximately equal, and the zero-sequence mutual impedance can be calculated.

[0106] Specifically, it can be expressed as:

[0107]

[0108] According to the elements of the off-diagonal blocks, take the arithmetic mean and multiply it by 3 to obtain the zero-sequence mutual impedance of the double-circuit line:

[0109]

[0110] Similarly, the full-phase admittance matrix of the double-circuit line is calculated to obtain the admittance relationship between the phases. This matrix is ​​also 6×6 and can be divided into 4 blocks.

[0111]

[0112] The zero-sequence mutual susceptance is calculated from the off-diagonal blocks of the admittance matrix.

[0113]

[0114] in,

[0115] According to the relationship between capacitance and susceptance, the zero-sequence mutual capacitance of double-circuit transmission lines is calculated:

[0116]

[0117] According to the full-phase impedance matrix and the full-phase admittance matrix, the off-diagonal matrix elements are extracted and transformed. The final self-sequence parameters and mutual-sequence parameters are obtained in the form of block diagonal matrix.

[0118] Through matrix transformation, the self-sequence parameter and mutual-sequence parameter Z of the double-circuit line are obtained. 01 , Z +1 , Z -1 , Z 02 , Z +2 , Z -2 , The mutual sequence parameters only contain the zero sequence component, and the positive and negative sequence components are decoupled, which facilitates the subsequent line operation analysis and scheduling.

[0119] The principle on which the present invention is based is that, in the case of double-circuit operation, the self-sequence impedance of the line is equal to that of the single-circuit operation, and the mutual sequence parameters (mutual impedance and mutual capacitance) of the two-circuit lines have only zero-sequence components, but no positive-sequence and negative-sequence components, that is, the positive-sequence and negative-sequence components are decoupled. Since the distance between the two circuits is far from the distance between each phase in each circuit, and the transmission line is transposed between phases, the 9 elements in the non-diagonal blocks are approximately equal, and the average value of these elements is the mutual parameter of the two circuits, and the zero-sequence parameter is 3 times the mutual parameter. Based on this principle, the sequence parameters of the double-circuit line can be quickly identified.

[0120]

[0121] Where T is a block diagonal matrix

[0122]

[0123] Accordingly, the embodiments of the present application also provide a computer-readable storage medium, in which computer executable instructions are stored, and when the computer executable instructions are executed by the processor, the various method embodiments of the present application are implemented. Computer-readable storage media include permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information can be a computer-readable instruction, a data structure, a module of a program, or other data. Examples of computer storage media 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 technology, read-only compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable storage media does not include temporary computer-readable media (transitory media), such as modulated data signals and carriers.

[0124] In addition, an embodiment of the present application further provides a computer program product, which includes computer executable instructions, and when the computer executable instructions are executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0125] It should be noted that, in the present application, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the term "include", "comprise" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements defined by the sentence "include one" do not exclude the existence of other identical elements in the process, method, article or equipment including the elements. In the present application, if it is mentioned that a certain action is performed according to a certain element, it means at least the meaning of performing the action according to the element, which includes two situations: performing the action only according to the element and performing the action according to the element and other elements. Multiple, multiple, multiple, etc. expressions include 2, 2 times, 2 kinds and more than 2, more than 2 times, more than 2 kinds.

[0126] The serial numbers used in describing the steps of the method do not themselves constitute any limitation on the order of these steps. For example, the step with a larger serial number does not necessarily have to be executed after the step with a smaller serial number. The step with a larger serial number may be executed first and then the step with a smaller serial number. They may also be executed in parallel, as long as this execution order is reasonable for those skilled in the art. For another example, multiple steps with consecutive serial numbers (e.g., step 101, step 102, step 103, etc.) do not limit other steps that can be executed in between. For example, there may be other steps between step 101 and step 102.

[0127] This specification includes combinations of the various embodiments described herein. Individual references to embodiments (e.g., "one embodiment" or "some embodiments" or "preferred embodiments"); however, these embodiments are not mutually exclusive unless indicated as mutually exclusive or it is clear to a person skilled in the art that they are mutually exclusive. It should be noted that the word "or" is used in this specification in a non-exclusive sense unless the context clearly indicates or requires otherwise.

[0128] All documents mentioned in this specification are considered to be included in the disclosure of this application as a whole, so that they can be used as a basis for modification when necessary. In addition, it should be understood that the above is only a preferred embodiment of this specification and is not intended to limit the scope of protection of this specification. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of one or more embodiments of this specification should be included in the scope of protection of one or more embodiments of this specification.

Claims

1. A method for quickly identifying sequence parameters of double-circuit transmission lines, characterized in that: include: Step S1. Obtaining input data, wherein the input data includes double-circuit transmission line structure and component parameters; Step S2. construct a line model of a first single-loop transmission line, calculate the impedance matrix of the first single-loop transmission line based on the input data, obtain a first self-sequence impedance, and perform the same calculation on a second single-loop transmission line symmetrical to the first single-loop transmission line to obtain a second self-sequence impedance; Step S3. construct a line model of the double-circuit transmission line, and based on the input data, calculate the full-phase impedance matrix and full-phase admittance matrix corresponding to the six-phase conductors of the double-circuit transmission line to obtain zero-sequence mutual capacitance and zero-sequence mutual impedance; Step S4. Transform the impedance matrix and the admittance matrix, and combine them with the self-sequence impedance to obtain the self-sequence parameters and mutual-sequence parameters of the double-circuit transmission line. The self-sequence impedance of the double-circuit transmission line is the same as that of the single-circuit transmission line, and the mutual-sequence parameter has only a zero-sequence component, and the positive-sequence component and the negative-sequence component are decoupled.

2. The method for quickly identifying sequence parameters of double-circuit transmission lines according to claim 1, characterized in that: The obtaining of input data further comprises: Obtaining the parameters of the conductor and ground wire used in the double-circuit transmission line, including the number of splits of the split conductor, the split spacing, the number of aluminum steel strands in each sub-conductor, the radius, the DC resistance of the conductor, and the sag of the conductor; Obtaining the structural parameters of the double-circuit transmission line tower and insulator, and calculating the spatial position of each phase conductor suspension; The transposition information between the conductors of the double-circuit transmission line is obtained.

3. The method for quickly identifying sequence parameters of double-circuit transmission lines according to claim 1, characterized in that: The line model of building the first single-circuit transmission line further includes: Calculate the 3*3 impedance matrix corresponding to the 3-phase conductors of the first single-circuit transmission line and the 3*3 impedance matrix corresponding to the 3-phase conductors of the second single-circuit transmission line, by Calculate Z seq The first self-sequence impedance Z of the first single-circuit transmission line is obtained by 01 , Z +1 , Z -1 , and the second self-sequence impedance Z of the second single-circuit transmission line 02 , Z +2 , Z -2 ; If the first single-circuit transmission line is symmetrical to the second single-circuit transmission line, the parameter of the first self-sequence impedance is equal to the parameter of the second self-sequence impedance.

4. The method for quickly identifying sequence parameters of a double-circuit transmission line according to claim 1, characterized in that: The line model of building the double-circuit transmission line further includes: Calculate the 6*6 full-phase impedance matrix corresponding to the 6-phase conductors of the double-circuit transmission line, and divide the full-phase impedance matrix into 4 blocks: Among them, the non-diagonal blocks The 9 elements in are approximately equal, that is The zero-sequence mutual impedance of the double-circuit transmission line is 3 times the arithmetic mean of the 9 elements in 5. The method for quickly identifying sequence parameters of double-circuit transmission lines according to claim 1, characterized in that: The line model of building the double-circuit transmission line further includes: Calculate the 6*6 full-phase admittance matrix corresponding to the 6-phase conductors of the double-circuit transmission line, and divide the full-phase admittance matrix into 4 blocks: The zero-sequence mutual admittance of the double-circuit transmission line is 3 times the arithmetic mean of the 9 elements in in, According to the relationship between capacitance and susceptance, the zero-sequence mutual capacitance of the double-circuit transmission line is calculated:

6. The method for quickly identifying sequence parameters of double-circuit transmission lines according to claim 1, characterized in that: The step of transforming the impedance matrix and the admittance matrix to obtain the self-sequence parameters and the mutual-sequence parameters of the double-circuit transmission line further includes: Extracting off-diagonal matrix elements from the full-phase impedance matrix and the full-phase admittance matrix; Calculating mutual order parameters based on the extracted off-diagonal array elements; Where T is a block diagonal matrix; According to the calculation results, the mutual sequence parameters of the double-circuit transmission line are output.

7. The method for quickly identifying sequence parameters of double-circuit transmission lines according to claim 1, characterized in that: The double-circuit transmission line is composed of two independent single-circuit lines, namely a first single-circuit transmission line and a second single-circuit transmission line. The self-impedance of each single-circuit transmission line is not affected by the other single-circuit transmission line.

8. The method for quickly identifying sequence parameters of double-circuit transmission lines according to claim 1, characterized in that: The positive sequence parameter and the negative sequence parameter only have self-sequence parameters but no mutual sequence parameters.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are executed by a processor, the steps in the method according to any one of claims 1 to 8 are implemented.

10. A computer program product comprising computer executable instructions, characterized in that: When the computer executable instructions are executed by a processor, the steps in the method described in any one of claims 1 to 8 are implemented.

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