Ultrahigh-voltage power transmission line high-resistance grounding fault distance measurement method based on double-end zero-sequence component

Abstract

The invention discloses an ultrahigh-voltage power transmission line high-resistance grounding fault distance measurement method based on a double-end zero-sequence component, and relates to the technical field of fault distance measurement, and the method comprises the steps: building a corresponding equivalent dual-power system model for a single-line power transmission line when a grounding fault occurs; a comprehensive sequence network diagram is derived through a sequence component analysis method, a relation equation is established through zero-sequence current, zero-sequence voltage and zero-sequence impedance of two ends in the comprehensive sequence network diagram, a proportionality coefficient is calculated, and a grounding fault point is calculated through the total length of a line and the proportionality coefficient; if the type of the ultrahigh-voltage power transmission line is a double-line power transmission line, when any line has a grounding fault; respectively establishing a voltage equation based on a fault line and a voltage equation based on a non-fault line; calculating the two equations to obtain a proportionality coefficient, and obtaining a grounding fault point through the total length of the line and the proportionality coefficient; according to the method, load current is not considered, the calculation amount is small, the fault positioning speed is high, and meanwhile high precision is reserved.

Description

Technical Field

[0001] This invention relates to the field of fault location technology, and more specifically, to a method for locating high-resistivity grounding faults in ultra-high voltage transmission lines based on dual-end zero-sequence components. Background Technology

[0002] Accurate fault location in transmission lines is a prerequisite for maintenance personnel to quickly locate and eliminate faults. In recent years, various principles and methods for fault location have been proposed both domestically and internationally, resulting in a wealth of research findings. Based on the nature of the information used in the calculation, fault location algorithms can be divided into two categories: fault location using transient traveling waves (also known as the traveling wave method) and fault location algorithms using power frequency quantities. Both the traveling wave method and the power frequency quantity algorithm can be further divided into single-end fault location and double-end fault location, among which:

[0003] The application of traveling wave ranging is limited by problems such as the uncertainty of wave velocity, the ranging dead zone, and the high requirements for hardware. Moreover, the traveling wave ranging method requires a separate set of equipment, which not only increases investment costs but also makes maintenance more difficult. Therefore, the widespread application of this method still depends on the development of related technologies.

[0004] The single-ended ranging algorithm based on power frequency is greatly affected by the limited amount of information available, especially when there is transition resistance at the short circuit point. Generally, some assumptions or approximations are required, and the accuracy often cannot meet the requirements. According to past statistics, most faults are single-phase grounding and two-phase faults, and transition resistance is often present in grounding faults.

[0005] With the continuous improvement of power system automation and the development of communication technology, information between the two ends of a transmission line can be easily exchanged or transmitted to the next higher level dispatcher. Therefore, research on two-end fault location based on power frequency quantities has practical significance. Many researchers have done a lot of work on the algorithm and implementation of two-end fault location based on power frequency quantities and have achieved many research results. However, so far, most of these studies are based on simulation data, and it is still uncertain whether they can achieve satisfactory results when applied to actual systems. Existing two-end fault location methods based on power frequency quantities are mainly for long-distance transmission lines, taking into account the distributed parameters of the line, and have high ranging accuracy. However, due to the nature of the ranging method itself, the ranging accuracy is affected by the load current. At the same time, the computational load is large, and the convergence algorithm and the existence of spurious roots need to be considered.

[0006] Therefore, this application is hereby submitted. Summary of the Invention

[0007] The purpose of this invention is to provide a method for locating high-resistivity grounding faults in ultra-high voltage transmission lines based on dual-end zero-sequence components, so as to solve the problems existing in the above-mentioned background art.

[0008] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0009] Firstly, this application provides a method for locating high-resistance grounding faults in ultra-high voltage transmission lines based on dual-end zero-sequence components, including the following specific steps:

[0010] S1, Determine the type of ultra-high voltage transmission line. The types of ultra-high voltage transmission lines include single-line transmission lines and double-line transmission lines.

[0011] S211. When a ground fault occurs, if the ultra-high voltage transmission line is a single-line transmission line, establish an equivalent dual-power system model corresponding to the single-line transmission line.

[0012] S212, based on the equivalent dual-power system model and through the sequence component analysis method, the comprehensive sequence network diagram is derived, and the relationship equation is established through the zero-sequence current, zero-sequence voltage and zero-sequence impedance at both ends in the comprehensive sequence network diagram;

[0013] S213, the proportional coefficient is obtained by solving the relational equation, and the ground fault point is calculated by the line length between single-line transmission lines and the proportional coefficient.

[0014] S221, If ​​the ultra-high voltage transmission line is a double-line transmission line, when a ground fault occurs in any one of the double-line transmission lines;

[0015] S222, establish voltage equations based on faulted lines and voltage equations based on non-faulted lines in a double-track transmission line, respectively.

[0016] S223, the proportional coefficient is obtained by solving the voltage equations of the faulty line and the non-faulty line, and the ground fault point is obtained by the total length of the faulty line and the proportional coefficient.

[0017] Based on the above technical solution, the present invention can be further improved as follows.

[0018] Furthermore, the above relational equation is as follows: ; In the formula, This represents the zero-sequence voltage of the bus on the G side in the integrated sequence network diagram. This represents the zero-sequence current flowing from the G-side bus to the fault point in the integrated sequence network diagram. This represents the zero-sequence impedance of the line from the G-side bus to the fault point in the integrated sequence network diagram. This represents the zero-sequence voltage of the bus on the J side in the integrated sequence network diagram. This represents the zero-sequence current flowing from the J-side bus to the fault point in the integrated sequence network diagram. This represents the zero-sequence impedance of the line from the J-side bus to the fault point in the integrated sequence network diagram. This represents the full value of the zero-sequence impedance between lines G and J.

[0019] Furthermore, when the ultra-high voltage transmission line type experiencing a ground fault is a single-line transmission line, the proportionality coefficient is... or Specifically: ; ; In the formula, This represents the ratio of the distance from fault point K to station G to the total length of line GJ. This represents the ratio of the distance from fault point K to station J to the total length of line GJ. This represents the zero-sequence voltage of the bus on the G side in the integrated sequence network diagram. This represents the zero-sequence current flowing from the G-side bus to the fault point in the integrated sequence network diagram. This represents the zero-sequence voltage of the bus on the J side in the integrated sequence network diagram. This represents the zero-sequence current flowing from the J-side bus to the fault point in the integrated sequence network diagram. This represents the full value of the zero-sequence impedance between lines G and J.

[0020] Furthermore, the voltage equation based on the faulty line is as follows:

[0021] In the formula, This represents the zero-sequence voltage at terminal M of the faulty line in a double-track transmission line. This represents the zero-sequence voltage at the N-terminal of the faulty line in a double-track transmission line. This represents the ratio of the distance from the fault point to terminal M to the total length of the faulty line MN. This represents the zero-sequence impedance of the faulty line MN. This represents the zero-sequence current at terminal M of the faulty line in a double-track transmission line. This represents the mutual inductance impedance between the two lines of a double-track transmission line. This represents the zero-sequence current at the N-terminal of the faulty line in a double-track transmission line. This represents the zero-sequence current at the N-end of the non-faulty line in a double-track transmission line. This represents the zero-sequence current at end M of the non-faulty section of a double-track transmission line, and .

[0022] Furthermore, the voltage equation based on the faulty line is obtained through the voltage drop at the fault point in the faulty line, specifically as follows: ; ; and: ; In the formula, This represents the voltage drop from point M to point F in a faulty section of a double-track transmission line. This represents the ratio of the distance from the fault point to terminal M to the total length of the faulty line MN. This represents the zero-sequence impedance of the faulty line MN. This represents the zero-sequence current at terminal M of the faulty line in a double-track transmission line. This represents the mutual inductance impedance between the two lines of a double-track transmission line. This represents the zero-sequence current at the N-end of the non-faulty line in a double-track transmission line. This represents the voltage drop from terminal N to fault point F in a faulty section of a double-track transmission line. This represents the zero-sequence current at end M of the non-faulty line of a double-track transmission line. This represents the zero-sequence voltage at terminal M of the faulty line in a double-track transmission line. This represents the zero-sequence voltage at the N-terminal of the faulty line in a double-track transmission line.

[0023] Furthermore, the voltage equations based on the non-faulty lines are as follows: ; In the formula, This represents the zero-sequence voltage at terminal M of the faulty line in a double-track transmission line. This represents the zero-sequence voltage at the N-terminal of the faulty line in a double-track transmission line. This represents the zero-sequence impedance of the faulty line MN. This represents the zero-sequence current at end M of the non-faulty line of a double-track transmission line. This represents the mutual inductance impedance between the two lines of a double-track transmission line. This represents the zero-sequence current at terminal M of the faulty line in a double-track transmission line. This represents the zero-sequence current at the N-end of the faulty line in a double-track transmission line.

[0024] Furthermore, when the ultra-high voltage transmission line type experiencing a ground fault is a double-track transmission line, the specific proportional coefficient is as follows: ; In the formula, This represents the ratio of the distance from the fault point to terminal M to the total length of the faulty line MN. This represents the zero-sequence current at end M of the non-faulty line of a double-track transmission line. This represents the zero-sequence current at terminal M of the faulty line in a double-track transmission line. This represents the zero-sequence current at the N-end of the faulty line in a double-track transmission line.

[0025] Secondly, this application provides a high-resistance grounding fault location system for ultra-high voltage transmission lines based on dual-terminal zero-sequence components, applicable to the high-resistance grounding fault location method for ultra-high voltage transmission lines based on dual-terminal zero-sequence components in any of the first aspects, including:

[0026] The line type determination module is used to determine the type of ultra-high voltage transmission line, which includes single-line transmission lines and double-line transmission lines.

[0027] The single-line processing module is used to establish an equivalent dual-power system model corresponding to the single-line transmission line when a ground fault occurs, if the ultra-high voltage transmission line is a single-line transmission line.

[0028] The relational equation construction module is used to derive the comprehensive sequence network diagram based on the equivalent dual-power system model and the sequence component analysis method, and to establish relational equations based on the zero-sequence current, zero-sequence voltage and zero-sequence impedance at both ends of the comprehensive sequence network diagram.

[0029] The single-line fault point determination module is used to calculate the proportional coefficient based on the relational equation, and to calculate the grounding fault point using the line length and proportional coefficient between single-line transmission lines.

[0030] The dual-line processing module is used when a grounding fault occurs on either of the two lines of an ultra-high voltage transmission line.

[0031] The voltage equation construction module is used to establish voltage equations based on faulty lines and voltage equations based on non-faulty lines in a two-line transmission line, respectively.

[0032] The dual-line fault point determination module is used to calculate the proportional coefficient by solving the voltage equations of the faulty line and the non-faulty line, and to determine the ground fault point by the total length of the faulty line and the proportional coefficient.

[0033] Thirdly, this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the high-resistivity grounding fault location method for ultra-high voltage transmission lines based on dual-end zero-sequence components as described in the first aspect.

[0034] Fourthly, this application provides a non-transitory computer-readable storage medium that stores computer instructions that cause a computer to execute the high-resistance grounding fault location method for ultra-high voltage transmission lines based on dual-terminal zero-sequence components as described in any of the first aspects.

[0035] Compared with the prior art, the present invention has at least the following beneficial effects:

[0036] 1. Fault location calculation is based on zero-sequence components, without considering load current. At the same time, the dual-end location measurement avoids the influence of transition resistance on the location accuracy. It is applicable to the location of single-phase ground faults and two-phase ground faults and can cover most fault conditions.

[0037] 2. The ranging method is suitable for transmission lines with series compensation devices. It does not require searching to find the fault location, has less computation, faster fault location speed, and retains high accuracy. Attached Figure Description

[0038] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0039] Figure 1 This is a flowchart of the ranging method in an embodiment of the present invention;

[0040] Figure 2 This is a schematic diagram of an equivalent dual-power system model in an embodiment of the present invention;

[0041] Figure 3 This is a schematic diagram of the integrated order network diagram in an embodiment of the present invention;

[0042] Figure 4 This is a connection diagram of the ranging system in an embodiment of the present invention;

[0043] Figure 5 This is a schematic diagram of the connection of an electronic device in an embodiment of the present invention. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0045] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0046] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0047] In the description of the embodiments of the present invention, "multiple" means at least two.

[0048] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0049] Example 1: To address the problems of high investment costs, difficult equipment maintenance, and the significant impact of transition resistance on the accuracy of single-ended fault location algorithms based on power frequency quantities in current fault location methods, this example provides a high-resistance grounding fault location method for ultra-high voltage transmission lines based on double-ended zero-sequence components, such as... Figure 1 As shown, the specific steps include the following:

[0050] S1, determine the type of ultra-high voltage transmission line. The types of ultra-high voltage transmission lines include single-line transmission lines and double-line transmission lines.

[0051] Among them, a single-line transmission line is the case where three-phase electricity is transmitted between two substations through one set of lines, while a double-line transmission line is the case where three-phase electricity is transmitted between two substations through two sets of lines.

[0052] S211. When a ground fault occurs, if the ultra-high voltage transmission line is a single-line transmission line, establish an equivalent dual-power system model corresponding to the single-line transmission line.

[0053] In the event of a ground fault in a single-line transmission line, an equivalent dual-power system model can be established first, where the ground fault occurs via a transition resistor. The established equivalent dual-power system model is as follows: Figure 2 As shown, in Figure 2 In the diagram, G and J represent two substations, and the line between the two substations forms a single-line transmission line. Figure 2 In this context, K can represent the fault point where the fault occurs, and the corresponding Rg can represent the transition resistance of the ground fault. Figure 2 This means that a single-phase ground fault occurred at point K between substation G and substation J, via transition resistor Rg.

[0054] S212, based on the equivalent dual-power system model and through the sequence component analysis method, derives the comprehensive sequence network diagram, and establishes the relationship equations through the zero-sequence current, zero-sequence voltage and zero-sequence impedance at both ends of the comprehensive sequence network diagram.

[0055] Sequence component analysis (SCI) is an effective tool for analyzing three-phase voltage or current asymmetry in power systems. It decomposes the three-phase asymmetry components into positive-sequence, negative-sequence, and zero-sequence components to help identify system fault types. This method is relatively mature and will not be elaborated further here. Based on the results of SCI and combined with the equivalent dual-source system model mentioned above, a comprehensive sequence network diagram can be derived. The derived comprehensive sequence network diagram is shown below. Figure 3 As shown, Figure 3 From top to bottom, the network diagrams are positive sequence, negative sequence, and zero sequence. Since it is a single-phase ground fault, the three network diagrams are connected in series to form a comprehensive sequence network diagram.

[0056] Furthermore, in Figure 3 In the zero-order network portion of the synthesized order network diagram shown, the variables should satisfy the following: ; ; ; ; In the above formula, This represents the equivalent zero-sequence impedance of the bus on the G side in the synthesized sequence network diagram. Let J represent the equivalent zero-sequence impedance of the bus on the J side in the integrated sequence network diagram. Using the second equation on the G side and the second equation on the J side mentioned above, and considering that the total zero-sequence impedance of the line is the sum of the zero-sequence impedance from the fault point to the G side of the line and the zero-sequence impedance from the fault point to the J side of the line, we can obtain the following relational equation, which is the above relational equation: ; In the formula, This represents the zero-sequence voltage of the bus on the G side in the integrated sequence network diagram. This represents the zero-sequence current flowing from the G-side bus to the fault point in the integrated sequence network diagram. This represents the zero-sequence impedance of the line from the G-side bus to the fault point in the integrated sequence network diagram. This represents the zero-sequence voltage of the bus on the J side in the integrated sequence network diagram. This represents the zero-sequence current flowing from the J-side bus to the fault point in the integrated sequence network diagram. This represents the zero-sequence impedance of the line from the J-side bus to the fault point in the integrated sequence network diagram. This represents the full value of the zero-sequence impedance between lines G and J.

[0057] in, , , , The data can be obtained directly from the line protection devices in the substations on both sides of G and J. Let the total zero-sequence impedance of the entire line be a known value. Then, the above relational equation only contains... Two unknowns can be obtained through or Represents the proportionality coefficient. This is the ratio of the distance from the fault point to station G to the distance from the fault point K to station G, and the total length of line GJ. Let K represent the ratio of the distance from fault point K to station J to the total length of line GJ. Then:

[0058] , By combining the above relational equations, the proportionality coefficient can be calculated.

[0059] S213, the proportional coefficient is obtained by solving the relational equation, and the ground fault point is calculated by the line length between single-line transmission lines and the proportional coefficient.

[0060] The proportionality coefficient can be calculated using the relationship between the proportionality coefficient and the zero-sequence impedance, as well as the aforementioned equation. Therefore, when the ultra-high voltage transmission line experiencing a ground fault is a single-line transmission line, the proportionality coefficient is... or Specifically: ; ; In the formula, This represents the ratio of the distance from fault point K to station G to the total length of line GJ. This represents the ratio of the distance from fault point K to station J to the total length of line GJ. This represents the zero-sequence voltage of the bus on the G side in the integrated sequence network diagram. This represents the zero-sequence current flowing from the G-side bus to the fault point in the integrated sequence network diagram. This represents the zero-sequence voltage of the bus on the J side in the integrated sequence network diagram. This represents the zero-sequence current flowing from the J-side bus to the fault point in the integrated sequence network diagram. This represents the full value of the zero-sequence impedance between lines G and J.

[0061] Among them, after obtaining the proportionality coefficient (calculation) or (Both are acceptable), then the location of the fault point can be obtained from the total length of the line, such as the calculated value as... If the entire line is 1000m long, then the fault point is located 350m away from station G.

[0062] S221, If ​​the ultra-high voltage transmission line is a double-line transmission line, when a ground fault occurs in either of the double-line transmission lines.

[0063] Among them, in the double-line transmission line, there are two sets of transmission lines, MN Line 1 and MN Line 2, and the zero-sequence impedance of the two lines is the same; if a ground fault occurs in MN Line 1, no ground fault occurs in MN Line 2, and both lines are double-circuited on the same tower.

[0064] S222, establish voltage equations based on faulty lines and voltage equations based on non-faulty lines in a double-track transmission line.

[0065] Optionally, the voltage equation based on the faulty line described above is as follows: ; In the formula, This represents the zero-sequence voltage at terminal M of the faulty line in a double-track transmission line. This represents the zero-sequence voltage at the N-terminal of the faulty line in a double-track transmission line. This represents the ratio of the distance from the fault point to terminal M to the total length of the faulty line MN. This represents the zero-sequence impedance of the faulty line MN. This represents the zero-sequence current at terminal M of the faulty line in a double-track transmission line. This represents the mutual inductance impedance between the two lines of a double-track transmission line. This represents the zero-sequence current at the N-terminal of the faulty line in a double-track transmission line. This represents the zero-sequence current at the N-end of the non-faulty line in a double-track transmission line. This represents the zero-sequence current at end M of the non-faulty section of a double-track transmission line. Since the zero-sequence currents on both sides of the non-faulty section should be equal in magnitude and opposite in direction, then... .

[0066] The voltage equation based on the faulty line is obtained by the voltage drop at the fault point in the faulty line, specifically as follows: ; ; and: ; In the formula, This represents the voltage drop from point M to point F in a faulty section of a double-track transmission line. This represents the ratio of the distance from the fault point to terminal M to the total length of the faulty line MN. This represents the zero-sequence impedance of the faulty line MN. This represents the zero-sequence current at terminal M of the faulty line in a double-track transmission line. This represents the mutual inductance impedance between the two lines of a double-track transmission line. This represents the zero-sequence current at the N-end of the non-faulty line in a double-track transmission line. This represents the voltage drop from terminal N to fault point F in a faulty section of a double-track transmission line. This represents the zero-sequence current at end M of the non-faulty line of a double-track transmission line. This represents the zero-sequence voltage at terminal M of the faulty line in a double-track transmission line. This represents the zero-sequence voltage at the N-terminal of the faulty line in a double-track transmission line.

[0067] Specifically, the construction of the voltage equation based on the faulted line requires substituting a proportionality coefficient, which is expressed as follows in a double-track transmission line: The voltage drop from terminals M and N in the faulty circuit to fault point F is determined by the voltage drop across them. Then, based on the relationship between the zero-sequence voltage across M and N and the voltage drop from M and N to fault point F, we can deduce: Then we can obtain the voltage equation based on the faulty line mentioned above.

[0068] Since the zero-sequence current in the faulty line will generate a zero-sequence voltage drop in the non-faulty line, and through electromagnetic coupling of mutual inductance, the voltage equation for the non-faulty line can be obtained. Therefore, the voltage equation based on the non-faulty line can be: ; In the formula, This represents the zero-sequence voltage at terminal M of the faulty line in a double-track transmission line. This represents the zero-sequence voltage at the N-terminal of the faulty line in a double-track transmission line. This represents the zero-sequence impedance of the faulty line MN. This represents the zero-sequence current at end M of the non-faulty line of a double-track transmission line. This represents the mutual inductance impedance between the two lines of a double-track transmission line. This represents the zero-sequence current at terminal M of the faulty line in a double-track transmission line. This represents the zero-sequence current at the N-end of the faulty line in a double-track transmission line.

[0069] S223, the proportional coefficient is obtained by solving the voltage equations of the faulty line and the non-faulty line, and the ground fault point is obtained by the total length of the faulty line and the proportional coefficient.

[0070] Specifically, by using the voltage equations based on the faulty line and the voltage equations based on the non-faulty line mentioned above, the expression for the proportional coefficient can be obtained. Since the above steps define the proportional coefficient of a double-track transmission line as the ratio of the distance from the fault point to end M to the total length of the faulty line MN, when the ultra-high voltage transmission line type experiencing a ground fault is a double-track transmission line, the proportional coefficient is specifically: ; In the formula, This represents the ratio of the distance from the fault point to terminal M to the total length of the faulty line MN. This represents the zero-sequence current at end M of the non-faulty line of a double-track transmission line. This represents the zero-sequence current at terminal M of the faulty line in a double-track transmission line. This represents the zero-sequence current at the N-end of the faulty line in a double-track transmission line.

[0071] Specifically, if the proportional coefficient of a double-track transmission line is defined as the ratio of the distance from the fault point to the N-terminal to the total length of the faulty line MN, then this proportional coefficient can be calculated by constructing the voltage equations using the logic described above: ; In the formula, This represents the ratio of the distance from the fault point to terminal N to the total length of the faulty line MN.

[0072] The above derivation process is based on power system fault analysis and circuit theory, and fully considers the influence of zero-sequence mutual inductance on zero-sequence ranging. The final ranging formula is obtained through step-by-step analysis and simplification.

[0073] Example 2: This application provides a high-resistance grounding fault location system for ultra-high voltage transmission lines based on dual-terminal zero-sequence components, applied to the high-resistance grounding fault location method for ultra-high voltage transmission lines based on dual-terminal zero-sequence components in Example 1, such as... Figure 4 As shown, it includes:

[0074] The line type determination module is used to determine the type of ultra-high voltage transmission line, which includes single-line transmission lines and double-line transmission lines.

[0075] The single-line processing module is used to establish an equivalent dual-power system model corresponding to the single-line transmission line when a ground fault occurs, if the ultra-high voltage transmission line is a single-line transmission line.

[0076] The relational equation construction module is used to derive the comprehensive sequence network diagram based on the equivalent dual-power system model and the sequence component analysis method, and to establish relational equations based on the zero-sequence current, zero-sequence voltage and zero-sequence impedance at both ends of the comprehensive sequence network diagram.

[0077] The single-line fault point determination module is used to calculate the proportional coefficient based on the relational equation, and to calculate the grounding fault point using the line length and proportional coefficient between single-line transmission lines.

[0078] The dual-line processing module is used when a grounding fault occurs on either of the two lines of an ultra-high voltage transmission line.

[0079] The voltage equation construction module is used to establish voltage equations based on faulty lines and voltage equations based on non-faulty lines in a two-line transmission line, respectively.

[0080] The dual-line fault point determination module is used to calculate the proportional coefficient by solving the voltage equations of the faulty line and the non-faulty line, and to determine the ground fault point by the total length of the faulty line and the proportional coefficient.

[0081] Example 3: This application provides an electronic device, such as... Figure 5 As shown, it includes a memory, a processor, and a computer program stored in the memory and capable of running on the processor. When the processor executes the computer program, it implements the high-resistivity grounding fault location method for ultra-high voltage transmission lines based on dual-end zero-sequence components as described in Embodiment 1.

[0082] Example 4: This application provides a non-transitory computer-readable storage medium that stores computer instructions. The computer instructions cause the computer to execute the high-resistance grounding fault location method for ultra-high voltage transmission lines based on dual-terminal zero-sequence components described in Example 1.

[0083] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0084] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0085] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0086] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0087] Those skilled in the art will understand that all or part of the steps in the above facts and methods can be implemented by a program instructing related hardware. The program or the program described therein can be stored in a computer-readable storage medium. When the program is executed, it includes the following steps: at this time, the corresponding method steps are introduced. The storage medium can be ROM / RAM, magnetic disk, optical disk, etc.

[0088] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for locating high-resistivity grounding faults in ultra-high voltage transmission lines based on dual-terminal zero-sequence components, characterized in that, The specific steps include the following: S1, determine the type of ultra-high voltage transmission line, wherein the type of ultra-high voltage transmission line includes single-line transmission lines and double-line transmission lines; S211. When a ground fault occurs, if the ultra-high voltage transmission line is a single-line transmission line, establish an equivalent dual-power system model corresponding to the single-line transmission line. S212, based on the equivalent dual-power system model and through the sequence component analysis method, the comprehensive sequence network diagram is derived, and the relationship equation is established through the zero-sequence current, zero-sequence voltage and zero-sequence impedance at both ends in the comprehensive sequence network diagram; S213, the proportional coefficient is obtained by solving the relational equation, and the ground fault point is calculated by the line length between single-line transmission lines and the proportional coefficient. S221, If ​​the ultra-high voltage transmission line is a double-line transmission line, when a ground fault occurs in any one of the double-line transmission lines; S222, establish voltage equations based on faulted lines and voltage equations based on non-faulted lines in a double-track transmission line, respectively. S223, the proportional coefficient is obtained by solving the voltage equations of the faulty line and the non-faulty line, and the ground fault point is obtained by the total length of the faulty line and the proportional coefficient.

2. The method for locating high-resistance grounding faults in ultra-high voltage transmission lines based on dual-terminal zero-sequence components according to claim 1, characterized in that, The relational equation is as follows: ； In the formula, This represents the zero-sequence voltage of the bus on the G side in the integrated sequence network diagram. This represents the zero-sequence current flowing from the G-side bus to the fault point in the integrated sequence network diagram. This represents the zero-sequence impedance of the line from the G-side bus to the fault point in the integrated sequence network diagram. This represents the zero-sequence voltage of the bus on the J side in the integrated sequence network diagram. This represents the zero-sequence current flowing from the J-side bus to the fault point in the integrated sequence network diagram. This represents the zero-sequence impedance of the line from the J-side bus to the fault point in the integrated sequence network diagram. This represents the full value of the zero-sequence impedance between lines G and J.

3. The method for locating high-resistance grounding faults in ultra-high voltage transmission lines based on dual-terminal zero-sequence components according to claim 2, characterized in that, When the ultra-high voltage transmission line experiencing a ground fault is a single-line transmission line, the proportional coefficient is: or Specifically: ； ； In the formula, This represents the ratio of the distance from fault point K to station G to the total length of line GJ. This represents the ratio of the distance from fault point K to station J to the total length of line GJ. This represents the zero-sequence voltage of the bus on the G side in the integrated sequence network diagram. This represents the zero-sequence current flowing from the G-side bus to the fault point in the integrated sequence network diagram. This represents the zero-sequence voltage of the bus on the J side in the integrated sequence network diagram. This represents the zero-sequence current flowing from the J-side bus to the fault point in the integrated sequence network diagram. This represents the full value of the zero-sequence impedance between lines G and J.

4. The method for locating high-resistance grounding faults in ultra-high voltage transmission lines based on dual-terminal zero-sequence components according to claim 1, characterized in that, The voltage equation based on the faulty line is as follows: ； In the formula, This represents the zero-sequence voltage at terminal M of the faulty line in a double-track transmission line. This represents the zero-sequence voltage at the N-terminal of the faulty line in a double-track transmission line. This represents the ratio of the distance from the fault point to terminal M to the total length of the faulty line MN. This represents the zero-sequence impedance of the faulty line MN. This represents the zero-sequence current at terminal M of the faulty line in a double-track transmission line. This represents the mutual inductance impedance between the two lines of a double-track transmission line. This represents the zero-sequence current at the N-terminal of the faulty line in a double-track transmission line. This represents the zero-sequence current at the N-end of the non-faulty line in a double-track transmission line. This represents the zero-sequence current at end M of the non-faulty section of a double-track transmission line, and .

5. The method for locating high-resistance grounding faults in ultra-high voltage transmission lines based on dual-terminal zero-sequence components according to claim 4, characterized in that, The voltage equation based on the faulty line is obtained through the voltage drop at the fault point in the faulty line, specifically: ； ； and: ； In the formula, This represents the voltage drop from point M to point F in a faulty section of a double-track transmission line. This represents the ratio of the distance from the fault point to terminal M to the total length of the faulty line MN. This represents the zero-sequence impedance of the faulty line MN. This represents the zero-sequence current at terminal M of the faulty line in a double-track transmission line. This represents the mutual inductance impedance between the two lines of a double-track transmission line. This represents the zero-sequence current at the N-end of the non-faulty line in a double-track transmission line. This represents the voltage drop from terminal N to fault point F in a faulty section of a double-track transmission line. This represents the zero-sequence current at end M of the non-faulty line of a double-track transmission line. This represents the zero-sequence voltage at terminal M of the faulty line in a double-track transmission line. This represents the zero-sequence voltage at the N-terminal of the faulty line in a double-track transmission line.

6. The method for locating high-resistance grounding faults in ultra-high voltage transmission lines based on dual-terminal zero-sequence components according to claim 4, characterized in that, The voltage equation based on the non-faulty line is as follows: ； In the formula, This represents the zero-sequence voltage at terminal M of the faulty line in a double-track transmission line. This represents the zero-sequence voltage at the N-terminal of the faulty line in a double-track transmission line. This represents the zero-sequence impedance of the faulty line MN. This represents the zero-sequence current at end M of the non-faulty line of a double-track transmission line. This represents the mutual inductance impedance between the two lines of a double-track transmission line. This represents the zero-sequence current at terminal M of the faulty line in a double-track transmission line. This represents the zero-sequence current at the N-end of the faulty line in a double-track transmission line.

7. The method for locating high-resistance grounding faults in ultra-high voltage transmission lines based on dual-terminal zero-sequence components according to claim 6, characterized in that, When the ultra-high voltage transmission line experiencing a ground fault is a double-track transmission line, the proportional coefficient is specifically as follows: ； In the formula, This represents the ratio of the distance from the fault point to terminal M to the total length of the faulty line MN. This represents the zero-sequence current at end M of the non-faulty line of a double-track transmission line. This represents the zero-sequence current at terminal M of the faulty line in a double-track transmission line. This represents the zero-sequence current at the N-end of the faulty line in a double-track transmission line.

8. A high-resistivity grounding fault location system for ultra-high voltage transmission lines based on dual-end zero-sequence components, characterized in that, include: The line type determination module is used to determine the type of ultra-high voltage transmission line, which includes single-line transmission lines and double-line transmission lines; The single-line processing module is used to establish an equivalent dual-power system model corresponding to the single-line transmission line when a ground fault occurs, if the ultra-high voltage transmission line is a single-line transmission line. The relational equation construction module is used to derive the comprehensive sequence network diagram based on the equivalent dual-power system model and the sequence component analysis method, and to establish relational equations based on the zero-sequence current, zero-sequence voltage and zero-sequence impedance at both ends of the comprehensive sequence network diagram. The single-line fault point determination module is used to calculate the proportional coefficient based on the relationship equation, and to calculate the grounding fault point by using the line length between single-line transmission lines and the proportional coefficient. The dual-line processing module is used when a grounding fault occurs on either of the two lines of an ultra-high voltage transmission line. The voltage equation construction module is used to establish voltage equations based on faulty lines and voltage equations based on non-faulty lines in a two-line transmission line, respectively. The dual-line fault point determination module is used to calculate the proportional coefficient by solving the voltage equation of the faulty line and the voltage equation of the non-faulty line, and to determine the ground fault point by the total length of the faulty line and the proportional coefficient.

9. An electronic device, characterized in that, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the high-resistivity grounding fault location method for ultra-high voltage transmission lines based on double-ended zero-sequence components as described in any one of claims 1-7.

10. A non-transitory computer-readable storage medium, characterized in that, The non-transitory computer-readable storage medium stores computer instructions that cause the computer to execute any one of the claims 1-7, the method for locating high-resistance grounding faults in ultra-high voltage transmission lines based on dual-end zero-sequence components.

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