Method and system for installing gapless lightning arrester in middle of ultra-high voltage alternating current engineering line

Abstract

The invention discloses a method and system for installing a gapless lightning arrester in the middle of an ultra-high voltage alternating current project line, and belongs to the technical field of alternating current transmission. The invention provides a method for installing a gapless lightning arrester in the middle of an ultra-high-voltage alternating-current engineering line, which comprises the following steps of: for the ultra-high-voltage alternating-current engineering line, calculating line overvoltage, and selecting a lightning arrester structure according to key parameters of the lightning arrester based on the line overvoltage; according to the test verification result of the lightning arrester structure, selecting a gapless installation scheme of the lightning arrester structure for the middle part of the ultra-high voltage alternating current engineering line; and determining a project implementation scheme based on the installation scheme and the basic condition of the extra-high voltage alternating current project line, and installing a lightning arrester structure for the extra-high voltage alternating current project line based on the project implementation scheme. According to the method, the operation reliability of the ultra-high voltage line is remarkably improved, and the operation and maintenance workload is reduced.

Description

Technical Field

[0001] This invention relates to the field of AC power transmission technology, and more specifically, to a method and system for installing a gapless surge arrester in the middle of an ultra-high voltage AC power transmission line. Background Technology

[0002] As the nation vigorously promotes the "carbon peaking and carbon neutrality" initiative and strives to achieve the "dual carbon" goal as soon as possible, clean electricity from large energy bases in Northwest and Southwest China needs to be transmitted to load centers via ultra-high voltage (UHV) and extra-high voltage (EHV) transmission lines. In the future, UHV and EHV lines will increasingly traverse high-altitude regions, and this overall increase in altitude presents new challenges for the design and construction of UHV and EHV lines.

[0003] Due to the unique topography, geographical environment, and meteorological conditions of the areas traversed by ultra-high voltage and extra-high voltage transmission lines in high-altitude regions such as Northwest and Southwest China, many special factors need to be considered in the research of line surge arresters. Line surge arresters for transmission line lightning protection generally consist of an arrester body and an air gap connected in series. The discharge performance of the air gap varies with altitude and requires altitude correction. Therefore, high-altitude testing of the entire body and series gap is necessary to verify the discharge characteristics at different altitudes and determine the effectiveness of the protection, which is very difficult to implement. If the line surge arrester adopts a gapless structure, the residual voltage of the arrester body is not affected by altitude; only the external insulation needs to be adjusted for altitude. The gapless design eliminates the need for altitude correction and gap distance adjustment, facilitating installation and significantly reducing installation and testing workload. It also has a wider applicable altitude range, which is beneficial for the widespread application of line surge arresters in high-altitude areas.

[0004] Currently, surge arresters combined with closing resistors are commonly used to suppress switching overvoltages. However, the reliability of closing resistors is poor, and they have frequently failed in recent years, directly affecting the operational reliability of the power system. Therefore, by optimizing the parameters of surge arresters in substations and installing coordinated suppression surge arresters on lines, deep suppression of switching overvoltages can be achieved, reducing the insulation requirements of power equipment.

[0005] Currently, surge arresters for lightning protection generally adopt a gapped structure, which has the advantage of no aging and requires less maintenance in the later stages. However, when used to suppress switching overvoltages, the gap fit has a large degree of dispersion, making accurate matching impossible.

[0006] The line surge arrester adopts a gapless structure, eliminating the need for gap distance adjustment, simplifying installation, significantly reducing installation workload, and broadening its applicability, thus promoting the widespread application of line surge arresters. Gapless ultra-high voltage (UHV) and extra-high voltage (EHV) line surge arresters can meet both lightning overvoltage and switching overvoltage protection requirements, making them suitable for UHV and EHV line surge arrester applications requiring deep overvoltage suppression. This achieves the goals of reducing tower head gaps, decreasing transmission corridor width, and improving corridor utilization.

[0007] The gapless surge arrester adopts a gapless structure. Because the residual voltage of the arrester body is unaffected by altitude, temperature, humidity, wind speed, etc., it is easy to install, greatly reducing installation and testing workload. Gapless UHV / EHV line surge arresters can meet the protection requirements of both lightning overvoltage and switching overvoltage, and are suitable for UHV / EHV line surge arrester applications requiring deep overvoltage suppression. This achieves the goals of reducing tower head gaps, reducing transmission corridor width, and improving corridor utilization, showing broad application prospects. The lightweight and miniaturization of line surge arresters is an important means to achieve differentiated lightning protection design for lines in areas with special harsh environmental requirements such as heavy icing and strong winds. Reducing the size and weight of line surge arresters can reduce the bending and tensile loads caused by high seismic intensity and strong winds, improving long-term operational stability. UHV / EHV line surge arresters are large, heavy, and installed at high positions, making power outage inspection very difficult; however, effective inspection methods and maintenance means for line surge arresters are currently lacking. This project is expected to yield significant benefits in improving the operational reliability and effectiveness of live-line diagnostics for surge arresters on ultra-high voltage (UHV) and extra-high voltage (EHV) power lines, and will also simplify on-site testing. It will also provide substantial economic benefits in terms of saving power outage time, reducing workload, and improving the efficiency of surge arrester operation and maintenance.

[0008] Currently, surge arresters on power lines are mainly installed in two ways: suspended installation and pedestal installation. Suspended installation has a wider range of applications and is simpler to install, while pedestal installation is implemented under specific structures and tower types. More than 90% of line surge arresters are suspended. Suspended installation is further divided into upright installation and inverted installation, i.e., whether the high-voltage end is above or below the surge arrester. Sometimes the surge arrester is suspended on a crossarm, and sometimes it is suspended on the conductor. The optimal choice is made for different tower types (single-circuit, double-circuit, tension tower, straight-line tower, and goblet tower, etc.).

[0009] Ultra-high voltage (UHV) and extra-high voltage (EHV) line surge arresters are heavy and long. During installation, it is crucial to consider not only the mechanical properties of the arrester itself, but also its impact on the safety and stability of the transmission line towers and conductors due to its weight. Furthermore, the optimal fit between the arrester's length and the available installation space must be carefully considered. These aspects require in-depth research. Based on the gapless line surge arrester technology, optimal selection must be made for different tower types (single-circuit, double-circuit, tension towers, straight-line towers, and goblet towers, etc.). While considering the lightweight and miniaturization of line surge arresters, the impact of severe environmental conditions such as repeated icing, strong winds, and light wind vibrations on the equipment and its installation needs to be studied to improve long-term operational stability.

[0010] Research work on line surge arresters includes key technology research on surge arresters for ultra-high voltage AC and DC lines in high-altitude areas, research on the characteristics and configuration of surge arresters for ±1100kV DC transmission projects, and development of surge arresters for ±400kV and ±660kV DC transmission lines in high-altitude areas. This research primarily focuses on line surge arresters with series gaps for lightning protection; no research has been conducted on gapless line surge arresters. Summary of the Invention

[0011] To address the above problems, this invention proposes a method for installing a gapless surge arrester in the middle of an ultra-high voltage AC power transmission line, comprising:

[0012] For ultra-high voltage AC engineering lines, the line overvoltage is calculated, and based on the line overvoltage, the surge arrester structure is selected according to the key parameters of the surge arrester.

[0013] Based on the test verification results of the surge arrester structure, the surge arrester structure for gapless installation in the middle of ultra-high voltage AC engineering lines was selected.

[0014] Based on the installation scheme and the basic conditions of the ultra-high voltage AC engineering line, the engineering implementation plan is determined. Based on the engineering implementation plan, surge arrester structures are installed on the ultra-high voltage AC engineering line.

[0015] Optional key parameters for surge arresters include: rated voltage parameters and protection level parameters.

[0016] Optional surge arrester structures include:

[0017] The first structural scheme includes: 4 columns connected in parallel and 4 sections connected in series;

[0018] The second structural scheme includes: two columns connected in parallel, two sections connected in parallel externally, and four sections connected in series.

[0019] Optional, test verification results include: resistive element operating load test results and long-term stability test results.

[0020] Optional installation options include:

[0021] The first installation scheme includes: the structure of the first scheme adopts an installation method in which the surge arrester is suspended above the conductor;

[0022] The second installation scheme includes: the second scheme adopts an installation method in which the surge arrester is suspended above the conductor;

[0023] The third installation scheme includes the installation method in which two parallel surge arresters of the structure of the second scheme are suspended on both sides of the tower above the conductor.

[0024] Optional, the basic information of ultra-high voltage and extra-high voltage AC transmission lines includes:

[0025] The overvoltage characteristics of ultra-high voltage AC transmission lines, the terrain and topography of the towers, and the limitations of surge arrester installation.

[0026] Furthermore, this invention also proposes an installation system for a gapless surge arrester in the middle of an ultra-high voltage AC transmission line, comprising:

[0027] Structural units are selected for calculating line overvoltages for ultra-high voltage AC engineering lines. Based on the line overvoltages, the surge arrester structure is selected according to the key parameters of the surge arrester.

[0028] The installation scheme selection unit is used to select the gapless installation scheme of the surge arrester structure for the middle of the ultra-high voltage AC engineering line based on the test verification results of the surge arrester structure.

[0029] The installation unit is used to determine the engineering implementation plan based on the installation scheme and the basic conditions of the ultra-high voltage AC engineering line, and to install the surge arrester structure on the ultra-high voltage AC engineering line based on the engineering implementation plan.

[0030] Optional key parameters for surge arresters include: rated voltage parameters and protection level parameters.

[0031] Optional surge arrester structures include:

[0032] The first structural scheme includes: 4 columns connected in parallel and 4 sections connected in series;

[0033] The second structural scheme includes: two columns connected in parallel, two sections connected in parallel externally, and four sections connected in series.

[0034] Optional, test verification results include: resistive element operating load test results and long-term stability test results.

[0035] Optional installation options include:

[0036] The first installation scheme includes: the structure of the first scheme adopts an installation method in which the surge arrester is suspended above the conductor;

[0037] The second installation scheme includes: the second scheme adopts an installation method in which the surge arrester is suspended above the conductor;

[0038] The third installation scheme includes the installation method in which two parallel surge arresters of the structure of the second scheme are suspended on both sides of the tower above the conductor.

[0039] Optional, the basic information of ultra-high voltage and extra-high voltage AC transmission lines includes:

[0040] The overvoltage characteristics of ultra-high voltage AC transmission lines, the terrain and topography of the towers, and the limitations of surge arrester installation.

[0041] In another aspect, the present invention also provides a computing device, comprising: one or more processors;

[0042] A processor is used to execute one or more programs;

[0043] When the one or more programs are executed by the one or more processors, the method described above is implemented.

[0044] In another aspect, the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed, implements the method described above.

[0045] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0046] This invention provides a method for installing a gapless surge arrester in the middle of an ultra-high voltage (UHV) AC power transmission line. The method includes: calculating the line overvoltage for the UHV AC power transmission line; selecting the surge arrester structure based on the line overvoltage and key parameters of the surge arrester; selecting an installation scheme for the gapless middle section of the UHV AC power transmission line based on experimental verification results of the surge arrester structure; determining an engineering implementation plan based on the installation scheme and the basic conditions of the UHV AC power transmission line; and installing the surge arrester structure on the UHV AC power transmission line based on the engineering implementation plan. This invention can address both lightning overvoltage and switching overvoltage protection requirements, and is suitable for UHV line surge arrester applications requiring deep overvoltage suppression. This achieves the goals of reducing tower head gaps, decreasing transmission corridor width, and improving corridor utilization, significantly enhancing the operational reliability of UHV lines and reducing maintenance workload. Attached Figure Description

[0047] Figure 1 This is a flowchart of the method of the present invention;

[0048] Figure 2 This is a schematic diagram of the lightning protection structure of Scheme 1 in the embodiment of the method of the present invention;

[0049] Figure 3 This is a schematic diagram of the lightning protection structure of Scheme 2 in the embodiment of the method of the present invention;

[0050] Figure 4 This is a schematic diagram of the lightning protection structure installation scheme of Scheme 1 in the embodiment of the method of the present invention;

[0051] Figure 5 This is a schematic diagram of the lightning protection structure installation scheme of Scheme 2 in the embodiment of the method of the present invention;

[0052] Figure 6 This is a schematic diagram of the lightning protection structure installation scheme of Scheme 3 in the embodiment of the method of the present invention;

[0053] Figure 7 This is a line fault and overvoltage distribution diagram along the line during the clearing process in an embodiment of the method of the present invention;

[0054] Figure 8 This is a diagram showing the distribution of overvoltage along the line during different line faults and clearing processes in an embodiment of the method of the present invention;

[0055] Figure 9 This is a schematic diagram of the lightning arrester installation tower window and suspension bracket in an embodiment of the method of the present invention;

[0056] Figure 10 This is a front view of the installation of the mid-phase surge arrester in an embodiment of the method of the present invention;

[0057] Figure 11 This is a side view of the installation of the mid-phase surge arrester in an embodiment of the method of the present invention;

[0058] Figure 12 This is a circular diagram of the gap between the middle phase surge arresters in an embodiment of the method of the present invention;

[0059] Figure 13 This is a top view of the flange dimensions in an embodiment of the method of the present invention;

[0060] Figure 14 This is a schematic diagram of a special connecting plate for four-split conductors in an embodiment of the method of the present invention;

[0061] Figure 15 This is a schematic diagram of the drain line connection in an embodiment of the method of the present invention;

[0062] Figure 16 This is a schematic diagram of the arrester counter installation in an embodiment of the method of the present invention;

[0063] Figure 17 This is a circular diagram of the gap between the side-phase surge arresters in an embodiment of the method of the present invention;

[0064] Figure 18 This is a diagram showing the connection between the lower end of the side-phase surge arrester and the side-phase support of the tower in an embodiment of the method of the present invention;

[0065] Figure 19 These are the layout diagrams of the suspended tandem plates 4L016 and 4R017 in the embodiment of the method of the present invention;

[0066] Figure 20 This is a schematic diagram of the side-phase suspension series plate in an embodiment of the method of the present invention;

[0067] Figure 21 This is a schematic diagram of the installation of the side phase counter in an embodiment of the method of the present invention;

[0068] Figure 22 This is a schematic diagram of the mounting points of the mid-phase surge arrester in an embodiment of the method of the present invention;

[0069] Figure 23 This is a schematic diagram of a reference style for a connecting clamp in an embodiment of the method of the present invention;

[0070] Figure 24 This is a structural diagram of the system of the present invention. Detailed Implementation

[0071] Exemplary embodiments of the invention will now be described with reference to the accompanying drawings. However, the invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the invention and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the drawings is not intended to limit the invention. In the drawings, the same units / elements are referred to by the same reference numerals.

[0072] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0073] Example 1:

[0074] This invention proposes a method S100 for installing a gapless surge arrester in the middle of an ultra-high voltage AC power transmission line, as follows: Figure 1 As shown, it includes:

[0075] S101, For ultra-high voltage AC engineering lines, calculate the line overvoltage, and based on the line overvoltage, select the surge arrester structure according to the key parameters of the surge arrester;

[0076] S102. Based on the test verification results of the surge arrester structure, the surge arrester structure for gapless installation in the middle of ultra-high voltage AC engineering lines is selected.

[0077] S103. Based on the installation scheme and the basic conditions of the ultra-high voltage AC engineering line, determine the engineering implementation plan. Based on the engineering implementation plan, install surge arrester structures on the ultra-high voltage AC engineering line.

[0078] The key parameters of surge arresters include: rated voltage parameters and protection level parameters.

[0079] The surge arrester structure includes:

[0080] The first structural scheme includes: 4 columns connected in parallel and 4 sections connected in series;

[0081] The second structural scheme includes: two columns connected in parallel, two sections connected in parallel externally, and four sections connected in series.

[0082] The test verification results include: resistive element action load test results and long-term stability test results.

[0083] The installation plan includes:

[0084] The first installation scheme includes: the structure of the first scheme adopts an installation method in which the surge arrester is suspended above the conductor;

[0085] The second installation scheme includes: the second scheme adopts an installation method in which the surge arrester is suspended above the conductor;

[0086] The third installation scheme includes the installation method in which two parallel surge arresters of the structure of the second scheme are suspended on both sides of the tower above the conductor.

[0087] The basic conditions of ultra-high voltage AC transmission lines include:

[0088] The overvoltage characteristics of ultra-high voltage AC transmission lines, the terrain and topography of the towers, and the limitations of surge arrester installation.

[0089] The invention will be further explained below with specific examples:

[0090] The main implementation steps include:

[0091] Comparison of selected line surge arrester schemes:

[0092] Based on the overvoltage calculation results of ultra-high voltage and extra-high voltage lines, this study investigates the selection of key parameters such as rated voltage and protection level of surge arresters, proposes an application scheme for ultra-high voltage and extra-high voltage AC line surge arresters suitable for deep overvoltage suppression requirements, and demonstrates the long-term stable operation capability of the selected line surge arresters based on the resistance element operating load and long-term stability test results, thus completing the relevant technical scheme demonstration for line surge arresters.

[0093] Surge arrester structural design:

[0094] Option 1: A 4-column parallel structure with a Φ358*2710 4-section series structure in the outer casing. The outline is shown in the figure. Figure 2 As shown, the parameters are shown in Table 1.

[0095] Table 1

[0096]

[0097] Option 2: Two columns connected in parallel, two sections connected in parallel externally, with an outer casing of Φ300*2760, and four sections connected in series. The outline is shown in the figure. Figure 3 As shown in Table 2, the parameters are as follows.

[0098] Table 2

[0099]

[0100] Lightning arrester installation plan:

[0101] Option 1: The four-column parallel structure uses a surge arrester installation method where the surge arrester is suspended above the conductor. The installation method is as follows: Figure 4 As shown:

[0102] Option 2, a structure with two internal parallel connections and two external parallel connections, uses a surge arrester installation method where the arrester is suspended above the conductor. The installation method is as follows: Figure 5 As shown:

[0103] Option 3 involves using two parallel surge arresters suspended on either side of the tower to improve the stress on the tower. The installation plan is as follows: Figure 6 As shown:

[0104] All of the above solutions should take note of the problem that the high-voltage terminal wiring of the surge arrester is prone to breakage due to long-term vibration from light winds.

[0105] Determine the project implementation plan:

[0106] Taking into account the overvoltage characteristics of transmission lines, the terrain and topography of the towers, and the current limitations of surge arrester design and installation, the optimal installation location for line surge arresters is determined, and recommendations for tower locations are proposed. When installing surge arresters for ultra-high voltage and extra-high voltage lines, it is necessary to consider not only the mechanical performance of the arrester itself, but also the impact of the arrester's weight on the safety and stability of the transmission line towers, as well as the reasonable matching of the arrester length with the installation space; these aspects require in-depth study.

[0107] Based on the tower conditions, determine the installation methods for line surge arresters on straight-line towers and tension towers, and propose tower installation schemes for surge arresters. Coordinate with tower design units to conduct verification of the tower's mechanical and electrical performance, and complete tower reinforcement and installation accessory preparation work. Consider the possibility of installing intelligent online monitoring devices for line surge arresters.

[0108] Line surge arrester monitoring solution:

[0109] To reduce the workload of later-stage maintenance of line surge arresters, research needs to be conducted on intelligent online monitoring devices for line surge arresters. For ease of observation, wireless transmission monitoring devices are required for line surge arrester monitoring.

[0110] Based on existing monitors, and considering both product versatility and reusability, a transmission control unit needs to be developed. This unit utilizes an outdoor waterproof enclosure, housing a battery, communication control board, 4G communication module, and solar charge / discharge controller. Externally connected to the control unit enclosure are solar panels, a 4G communication antenna, and the monitor. When sufficient sunlight is available, the solar panels charge the internal battery, which powers the entire unit. The transmission control unit periodically collects data from the monitors and transmits it to a data platform via the 4G network. An interface for online monitoring data analysis is reserved to enable platform applications.

[0111] The following details the application scheme and installation method of surge arresters for ultra-high voltage AC lines, based on the above implementation steps:

[0112] Calculate the suppression of overvoltage along the line by the MOA in the middle of the line:

[0113] To further suppress overvoltage along the line, the installation of MOA in the middle of the line was considered. Different MOA configuration schemes were studied, including MOA with a rated voltage of 828kV and MOA with low residual voltage, and different installation positions were also considered.

[0114] First, consider the scenario where a set of MOA with a rated voltage of 828kV is installed at the middle half of the line. Figure 7 The distribution of overvoltage along the line during different line faults and clearing processes is presented when one 828kV MOA is installed in the middle of the line.

[0115] The calculation results show that after installing an 828kV MOA at the middle half of the line, the overvoltage during fault clearance was reduced. Under single-phase fault conditions, the highest overvoltage along the Ganzi-Tianfu South line is 1.53 pu; it may still exceed 1.5 pu.

[0116] Considering the installation of one low residual voltage MOA with a rated voltage of 828kV along the line, Figure 8 The distribution of overvoltage along the line during different line faults and clearing processes is presented when an 828kV MOA is installed in the middle of the line.

[0117] The calculation results show that after installing one set of low residual voltage MOA with a rated voltage of 828kV along the line, the fault clearance overvoltage was reduced. Under single-phase fault conditions in each section of the line, the highest overvoltage along the line was 1.50pu.

[0118] Lightning arrester installation and layout plan:

[0119] The installation location of the surge arrester is as follows:

[0120] The surge arrester is suspended. The upper end of the middle phase surge arrester is suspended from the extended bracket above the conductor, such as... Figure 9 As shown, the lower end is connected to the conductor; the upper end of the side-phase surge arrester is connected to the suspension plate of the conductor suspension string, and the lower end is connected to the side-phase support of the tower via steel strands. The side-phase surge arrester is connected to the suspension plate, and the weight of the surge arrester has been taken into account in the design of the conductor suspension string.

[0121] Installation scheme for medium-phase surge arresters:

[0122] The middle phase surge arrester is installed on the extended bracket in the middle of the tower window, as shown in the front view. Figure 10 As shown, the side view is as follows Figure 11 As shown.

[0123] 1) Surge arrester bracket dimensions:

[0124] The projected length of the V-string of the medium conductor is 10.611m, which is less than the 15.5m length between the suspension points of a single-column surge arrester. Therefore, the surge arrester is suspended using an external cantilever bracket. The surge arrester suspension point on the external cantilever bracket of the medium conductor needs to be raised 3.889m from the top surface of the crossbeam. To allow for adjustment space, a cantilever height of 4.5m is considered. The remaining length difference can be adjusted by adjusting the length of the hinge hardware to make the distance from the external cantilever bracket to the conductor equivalent to the length of the surge arrester. The projected length of the V-string of the medium conductor and the dimensions of the surge arrester bracket are shown in Table 3.

[0125] Table 3

[0126]

[0127] 2) Surge arrester gap requirements:

[0128] The length of the cantilever support along the power line needs to meet the requirement that the surge arrester will not collide with the tower under wind load after installation. Additionally, the air gap requirement between the segmented flange and the grounding component must be considered. Since the lower end of the surge arrester is connected to the dedicated conductor connecting plate, the calculated angle of the surge arrester swinging along the power line with the conductor is less than 1°, and its impact can be ignored.

[0129] Based on the research conclusions on insulation configuration and air gap of ultra-high voltage AC engineering, the operating clearance of the middle phase V-string to the side is 7.2m at an altitude of 1500m. A 5-section surge arrester is selected. The air gap requirements for the segmented flanges to the grounding components are as follows: 1.44m between the flanges of the 1st and 2nd sections, 2.88m between the flanges of the 2nd and 3rd sections, and 4.32m between the flanges of the 3rd and 4th sections. Because the lower end of the surge arrester connects to the conductor, the swing angle is relatively small. Considering a certain margin, a horizontal displacement of 500mm at the lower end is tentatively considered. The design crossarm width is 2.8m. When the surge arrester hanging point is offset longitudinally by 6.6m from the edge of the crossarm, considering that the surge arrester has not been tendered, the reserved air gap margin between the surge arrester flange and the crossarm is approximately 1.78m. The surge arrester is divided into 5 sections, each 2.572m long. The segmented surge arrester flanges have pressure relief ports, with dimensions as shown... Figure 12 As shown. During construction and installation, the pressure relief port should be positioned away from the tower to increase the safety distance. Its flange dimensions are as follows. Figure 13 As shown.

[0130] 3) Connection between surge arrester and conductor:

[0131] When the surge arrester is suspended directly above the conductor, the grounding terminal (upper end) of the surge arrester is connected to the tower using an EB mounting plate. The high-voltage terminal (lower end) of the surge arrester is designed as a ring, led out through a U-shaped ring, and the length is adjusted in the middle using PT and DB adjustment plates. Finally, it is connected to the reserved hole of the four-split special connecting plate through a U-shaped ring. If the implemented surge arrester string length is short and needs to be extended significantly, it is recommended to add extension hardware at the low-voltage end.

[0132] The special connector A and B clamps are the same as the ordinary spacer bar FJZ-840 / 35D clamps, such as... Figure 14 As shown, it is equipped with an internal rubber pad; the C and D clamps are the same as the pre-twisted clamps of the FJZ-840 / 35DY pre-twisted spacer bar; the gripping force of a single clamp is not less than 2.5kN, and the axial (transverse) and oblique strength of a single clamp is not less than 2.5kN. Other requirements such as centripetal force and gripping torque are the same as those of the spacer bar FJZ-840 / 35D in this project, and the connection dimensions are matched with U-16; when the special connecting plate A and B clamps are fastened to the conductor, the fastening bolts must be inserted towards the inside of the equalizing ring of the surge arrester to reduce the corona effect.

[0133] Before leaving the factory, hardware must be trial assembled. Hardware manufacturers should ensure that hardware parts do not touch or jam. Before lifting, construction units should trial assemble the hardware and surge arrester and ensure that the drain line and surge arrester are correctly connected before lifting and starting work.

[0134] Under normal operation, the surge arrester carries a current of 20-30mA. Under switching overvoltage conditions, the surge arrester's 30 / 60μs discharge current is 300-500A. It is recommended to use a drain wire to connect the line conductor to the surge arrester. The drain wire should be LJ-300 aluminum stranded wire with a current carrying capacity of 550A. Figure 15 As shown, to reduce the impact of corona discharge, two lead wires are used. The lower end of the lead wire is hydraulically crimped to the TL clamp. The bolted section of the TL clamp is installed on the upper conductor between the surge arrester and the tower. During construction, it is important to ensure that the TL clamp is installed close to the dedicated connecting plates A and B, and that the TL clamp and lead wire are within the range covered by the equalizing ring diameter of the surge arrester. The upper end of the lead wire is connected to the high-voltage end (lower end) of the surge arrester using a SY hydraulic type equipment clamp. The lead wire should be kept as long as possible to reduce the impact of corona discharge. The length should be slightly longer than the hinge hardware, ensuring that the lead wire is not under stress and that the TL clamp is installed close to the dedicated connecting plates A and B. Before construction, the construction unit confirmed on-site that the actual length of the hinge hardware after installation at the high-voltage end (lower end) of the surge arrester is less than the length of the lead wire. For the two lead wires and hinge hardware, a certain distance should be maintained during installation to prevent them from tangling. The excess length of the lead wire should be placed inside the eight-split conductor. In actual implementation, the lead wires will need to be recalculated and reselected.

[0135] 4) Lightning arrester counter installation design:

[0136] The surge arrester counter is mounted on the horizontal member of the equilateral triangle of the tower's cantilever support using a clamp, and is connected to the grounding terminal (upper end) of the surge arrester via the surge arrester's grounding wire. Figure 16 As shown. During installation, the surge arrester counter display should face outwards for easy observation (or it is recommended that the surge arrester counter be wireless). Keep the surge arrester grounding wire loose. During construction and installation, actually measure the straight-line distance between the counter and the surge arrester grounding terminal. The length of the surge arrester grounding wire should be appropriately increased based on the straight-line distance, ensuring that the counter and the surge arrester grounding terminal are on the same side, and that the hinge hardware and the grounding wire do not cross. A grounding hole should be pre-drilled on the horizontal member of the equilateral triangle, and the counter grounding wire should be connected to the grounding hole using bolts. The surge arrester grounding wire and the counter grounding wire are provided by the surge arrester manufacturer.

[0137] 5) Adjustment of surge arrester connection hardware:

[0138] When installing surge arresters, offset them 8m to the side of the line with the smaller number. The distance between the arrester bracket hanging point and the connecting plate at the lower end of the arrester and the conductor should take into account the sag at the conductor exit. Based on the actual cross-sectional information of the line, the distance between the arrester hanging point and the center of the conductor connecting plate on tower 4L016 can be calculated to be approximately 16.8m, and the distance between the arrester hanging point and the center of the conductor connecting plate on tower 4R017 can be approximately 15.6m. The above calculated values ​​are recommended reference lengths, which can be adjusted by adjusting the connecting plate of the surge arrester during implementation.

[0139] Side-phase surge arrester installation scheme:

[0140] The side-phase surge arrester adopts a scheme in which the high-voltage end is connected to the conductor connecting plate below the suspension string, and the grounding end is connected to the side-phase support of the tower through a drain line.

[0141] 1) Side-phase suspension string configuration scheme:

[0142] The surge arrester is suspended on the suspension string conductor connecting plate via connecting hardware. The surge arrester weighs approximately 3500 kg. Based on actual conditions, the calculated string tonnage for tower 4L016# is 420 kN double-connected, and for tower 4R017# it is 300 kN double-connected. Considering the suspension insulator string suspending the surge arrester, the suspension string tonnage for tower 4L016# is configured as 550 kN double-connected, and for tower 4R017# it is configured as 420 kN double-connected.

[0143] 2) Surge arrester gap requirements:

[0144] When installing surge arresters on one phase, in addition to considering the weight of the arrester itself, the safe distance between the suspension string and the arrester and the tower body under high wind conditions must also be considered. Based on calculations for high wind conditions, the wind deflection angle for tower 4L016# is 16.6°, for tower 4R017# it is 21.6°, and for the surge arrester it is 15.4°. Therefore, under high wind conditions, the safe distance between the energized components and the tower body is considered based on a 21.6° wind deflection angle for the suspension string and a 15.4° wind deflection angle for the surge arrester. (See...) Figure 17 .from Figure 17 As can be seen, the minimum distance between the charged body and the tower body under strong wind conditions is 9.86m, which meets the requirements of power frequency and operating clearance.

[0145] 3) Underside drain wire of surge arrester:

[0146] Because surge arresters need to discharge current when operating overvoltages are excessive, the lower end of the surge arrester needs to be connected to the side phase support of the tower via a drain line. Considering that the surge arrester experiences relatively small lateral forces, the drain line can limit the surge arrester's wind-induced sway. However, the suspension insulator string experiences significant lateral forces as it sways with the conductor. Therefore, the maximum calculated length of the drain line only needs to consider the swaying of the suspension insulator string away from the tower under high wind conditions. The calculated recommended installation length of the drain line is approximately 17.5m. For specific lateral sway distance and vertical height difference, please refer to [reference needed]. Figure 18 .from Figure 18 It can be seen that when the suspension string swings away from the tower, the swing of the surge arrester is limited by the drain line. When the suspension string swings close to the tower, the sag of the drain line is 7.9m, which has no effect on the tower.

[0147] During normal operation, the surge arrester's current carrying capacity is 20-30mA. Referring to the surge arrester of a ±1100kV DC line, under switching overvoltage conditions, the surge arrester's 30 / 60μs discharge current is 300-500A. Furthermore, it is necessary to consider limiting the surge arrester's own sway with the drain wire. Under 90° wind conditions, the maximum lateral force on the surge arrester is approximately 8500N, with a wind deflection angle of 15.4°. It is recommended to use JL / G1A-400 / 35 steel-cored aluminum stranded wire for the drain wire. JL / G1A-400 / 35 steel-cored aluminum stranded wire has an allowable current of 580A at 70℃ and a rated tensile strength of 103.67kN. When the recommended installation length of the surge arrester is approximately 17.5m, the horizontal tension of the surge arrester in its suspended state is approximately 900N. When the surge arrester deflects outward to its maximum extent during strong winds, it remains suspended due to the constraint of the surge arrester, with a horizontal tension of approximately 1800N. The lateral force on the surge arrester is generally no greater than 3000N. Therefore, the JL / G1A-400 / 35 steel-cored aluminum stranded wire meets the requirements for current and tensile strength. In actual implementation, the surge arrester will require further calculation and selection.

[0148] 4) Design of conductor suspension plate and its connection with surge arrester:

[0149] The upper end of the surge arrester is connected to the hanging hole located in the middle below the suspension plate via U-shaped hanging rings, parallel hanging plates, and other connecting hardware. The suspension plate requires a special design, with the spacing between the two lowest suspension clamp hanging holes increased to 550mm, and the hanging hole in the middle of the lower part of the suspension plate protruding downwards. The connected U-shaped hanging rings are designed according to UK-21100, as shown in the actual layout drawing. Figure 19 As can be seen, there was no collision between the suspension clamps on both sides and the surge arrester connecting hardware during operation.

[0150] Referring to the design of the energized section of the surge arrester, the surge arrester is connected to the conductor via two lead-in wires, which are LJ-300 aluminum stranded wires. The upper end of the lead-in wires is hydraulically crimped to the TL clamp, and the bolted section of the TL clamp is installed on the lower conductor. During construction, care must be taken to ensure that the TL clamp is installed close to the conductor clamp under the dedicated connecting plate, guaranteeing that the TL clamp and the lead-in wires are within the range covered by the equalizing ring diameter of the surge arrester. Figure 20 As shown; the lower end of the drain line is connected to the high-voltage end (upper end) of the surge arrester using a SY hydraulic type equipment clamp. The length of the drain line should be slightly longer than the hinge hardware, i.e., to ensure the drain line is not under stress, the TL clamp is installed tightly against the lower conductor clamp of the special connecting plate. Before construction, the construction unit confirmed on-site that the actual length of the hinge hardware at the high-voltage end (upper end) of the surge arrester after installation is less than the length of the drain line. For the two drain lines and hinge hardware, care should be taken to maintain a certain distance during installation to prevent them from getting tangled together, and the excess length of the drain line should be placed inside the eight-split conductor.

[0151] 5) Lightning arrester counter installation design:

[0152] The surge arrester counter is mounted on a base plate beneath the surge arrester body and connected to the grounding terminal (lower end) of the surge arrester via the surge arrester grounding wire. It is also connected to the U-shaped hanging ring bolts that connect the lower end of the surge arrester and the lead wire via the grounding wire. Figure 21 As shown. The surge arrester counter adopts a wireless transmission design and keeps the surge arrester grounding wire loose. During construction and installation, the actual straight-line distance between the counter and the U-shaped hanging ring bolt connecting the drain line should be measured. The length of the surge arrester grounding wire should be appropriately increased based on the straight-line distance, and the counter and the surge arrester grounding terminal should be on the same side. The hinge hardware and the grounding wire should not cross. The grounding wire and the U-shaped hanging ring bolt connecting hardware, the surge arrester grounding wire and the counter grounding wire are provided by the surge arrester manufacturer.

[0153] Surge arrester bracket design:

[0154] Lightning arrester load calculation:

[0155] The wind load of the surge arrester is considered as the wind load of the insulator string, and the load calculation is in accordance with the relevant clauses of the "Load Code for Overhead Transmission Lines" (DL / T 5551-2018).

[0156] Operating condition combinations:

[0157] Consider the following combinations of operating conditions, including:

[0158] (1) After the lightning arrester is installed on the tower and the line is strung, each phase conductor should be in the installed state when loading.

[0159] (2) The actual load conditions of tower positions 4L016 and 4R017 are adopted.

[0160] (3) The lifting load of the surge arrester bracket should be considered. Since the surge arrester is installed after the line construction is completed, the lifting load is only considered under the installation condition, with a wind speed of 10m / s. The surge arrester's self-weight is 3500kg, and the standard value of the lifting load is 35kN. The middle phase surge arrester bracket is equipped with a lifting hole at the hanging point, and the lifting load is considered to be twice the standard load. The design value of the vertical force under the lifting condition is 100.8kN.

[0161] (4) According to Clause 4.2.10 of the "Load Code for Overhead Transmission Lines" (DL / T 5551-2018), the wind direction at three basic wind speeds (0°, 45° (or 60°), and 90°) relative to the line direction should be calculated for suspended towers. Considering that the mid-phase surge arrester is perpendicular to the crossarm and differs from conventional tower types, the wind direction at four basic wind speeds (0°, 45°, 60°, and 90°) is calculated simultaneously for this project.

[0162] Connection scheme:

[0163] (1) Connection between the middle phase surge arrester and the support:

[0164] The surge arrester is connected to the bracket using an EB mounting plate, model EB-21 / 42-100. The angle steel for the mounting point is L140X12, made of Q355 steel. The clear distance between the angle steel pieces is 104mm, and the diameter of the mounting hole is 38mm. Figure 22 As shown.

[0165] (2) Connection between the side-phase surge arrester and the side-phase support of the tower:

[0166] The surge arrester is suspended from the suspension string plate via connecting hardware, and the lower end of the surge arrester is connected to the side phase support of the tower via a drain line. To reduce the length of the drain line, a support is extended at the slope change point of the tower, and the steel strand is connected to the support at a suitable position via clamps.

[0167] The fixture style can be referenced. Figure 23 .

[0168] The implementation of this invention can take into account the protection requirements of lightning overvoltage and switching overvoltage, and is suitable for the application of surge arresters for ultra-high voltage and extra-high voltage lines with deep overvoltage suppression requirements. This achieves the purpose of reducing tower head gap, reducing the width of transmission corridor, and improving corridor utilization, thereby significantly improving the operational reliability of ultra-high voltage and extra-high voltage lines and reducing maintenance workload.

[0169] Example 2:

[0170] Furthermore, this invention also proposes an installation system 200 for gapless surge arresters in the middle of ultra-high voltage AC engineering lines, such as... Figure 24 As shown, it includes:

[0171] Structural unit 201 is selected to calculate the line overvoltage for ultra-high voltage AC engineering lines. Based on the line overvoltage, the surge arrester structure is selected according to the key parameters of the surge arrester.

[0172] The installation scheme unit 202 is used to select an installation scheme for the surge arrester structure without gaps in the middle of the ultra-high voltage AC engineering line based on the test verification results of the surge arrester structure.

[0173] Installation unit 203 is used to determine the engineering implementation plan based on the installation scheme and the basic conditions of the ultra-high voltage AC engineering line, and to install surge arrester structures on the ultra-high voltage AC engineering line based on the engineering implementation plan.

[0174] The key parameters of surge arresters include: rated voltage parameters and protection level parameters.

[0175] The surge arrester structure includes:

[0176] The first structural scheme includes: 4 columns connected in parallel and 4 sections connected in series;

[0177] The second structural scheme includes: two columns connected in parallel, two sections connected in parallel externally, and four sections connected in series.

[0178] The test verification results include: resistive element action load test results and long-term stability test results.

[0179] The installation plan includes:

[0180] The first installation scheme includes: the structure of the first scheme adopts an installation method in which the surge arrester is suspended above the conductor;

[0181] The second installation scheme includes: the second scheme adopts an installation method in which the surge arrester is suspended above the conductor;

[0182] The third installation scheme includes the installation method in which two parallel surge arresters of the structure of the second scheme are suspended on both sides of the tower above the conductor.

[0183] The basic conditions of ultra-high voltage AC transmission lines include:

[0184] The overvoltage characteristics of ultra-high voltage AC transmission lines, the terrain and topography of the towers, and the limitations of surge arrester installation.

[0185] The implementation of this invention can take into account the protection requirements of lightning overvoltage and switching overvoltage, and is suitable for the application of surge arresters for ultra-high voltage and extra-high voltage lines with deep overvoltage suppression requirements. This achieves the purpose of reducing tower head gap, reducing the width of transmission corridor, and improving corridor utilization, thereby significantly improving the operational reliability of ultra-high voltage and extra-high voltage lines and reducing maintenance workload.

[0186] Example 3:

[0187] Based on the same inventive concept, this invention also provides a computer device, which includes a processor and a memory. The memory stores a computer program, which includes program instructions. The processor executes the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions in the computer storage medium to implement corresponding method flows or corresponding functions, thereby implementing the steps of the methods in the above embodiments.

[0188] Example 4:

[0189] Based on the same inventive concept, this invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device used to store programs and data. It is understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and extended storage media supported by the computer device. The computer-readable storage medium provides storage space that stores the terminal's operating system. Furthermore, this storage space also stores one or more instructions suitable for loading and execution by a processor. These instructions can be one or more computer programs (including program code). It should be noted that the computer-readable storage medium here can be high-speed RAM or non-volatile memory, such as at least one disk storage device. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of the method in the above embodiments.

[0190] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product implemented 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. The solutions in the embodiments of the present invention can be implemented using various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0191] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0192] 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.

[0193] 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.

[0194] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0195] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for installing a gapless surge arrester in the middle of an ultra-high voltage AC power transmission line, characterized in that, include: For ultra-high voltage AC engineering lines, the line overvoltage is calculated, and based on the line overvoltage, the surge arrester structure is selected according to the key parameters of the surge arrester. Based on the test verification results of the surge arrester structure, the surge arrester structure for gapless installation in the middle of ultra-high voltage AC engineering lines was selected. Based on the installation scheme and the basic conditions of the ultra-high voltage AC engineering line, the engineering implementation plan is determined. Based on the engineering implementation plan, surge arrester structures are installed on the ultra-high voltage AC engineering line.

2. The installation method according to claim 1, characterized in that, The key parameters of the surge arrester include: rated voltage parameters and protection level parameters.

3. The installation method according to claim 1, characterized in that, The surge arrester structure includes: The first structural scheme includes: 4 columns connected in parallel and 4 sections connected in series; The second structural scheme includes: two columns connected in parallel, two sections connected in parallel externally, and four sections connected in series.

4. The installation method according to claim 1, characterized in that, The test results include: resistive element action load test results and long-term stability test results.

5. The installation method according to claim 1, characterized in that, The installation scheme includes: The first installation scheme includes: the structure of the first scheme adopts an installation method in which the surge arrester is suspended above the conductor; The second installation scheme includes: the second scheme adopts an installation method in which the surge arrester is suspended above the conductor; The third installation scheme includes the installation method in which two parallel surge arresters of the structure of the second scheme are suspended on both sides of the tower above the conductor.

6. The installation method according to claim 1, characterized in that, The basic conditions of the ultra-high voltage AC transmission line include: The overvoltage characteristics of ultra-high voltage AC transmission lines, the terrain and topography of the towers, and the limitations of surge arrester installation.

7. An installation system for gapless surge arresters in the middle of ultra-high voltage AC power transmission lines, characterized in that, include: Structural units are selected for calculating line overvoltages for ultra-high voltage AC engineering lines. Based on the line overvoltages, the surge arrester structure is selected according to the key parameters of the surge arrester. The installation scheme selection unit is used to select the gapless installation scheme of the surge arrester structure for the middle of the ultra-high voltage AC engineering line based on the test verification results of the surge arrester structure. The installation unit is used to determine the engineering implementation plan based on the installation scheme and the basic conditions of the ultra-high voltage AC engineering line, and to install the surge arrester structure on the ultra-high voltage AC engineering line based on the engineering implementation plan.

8. The installation system according to claim 7, characterized in that, The key parameters of the surge arrester include: rated voltage parameters and protection level parameters.

9. The installation system according to claim 7, characterized in that, The surge arrester structure includes: The first structural scheme includes: 4 columns connected in parallel and 4 sections connected in series; The second structural scheme includes: two columns connected in parallel, two sections connected in parallel externally, and four sections connected in series.

10. The installation system according to claim 7, characterized in that, The test results include: resistive element action load test results and long-term stability test results.

11. The installation system according to claim 7, characterized in that, The installation scheme includes: The first installation scheme includes: the structure of the first scheme adopts an installation method in which the surge arrester is suspended above the conductor; The second installation scheme includes: the second scheme adopts an installation method in which the surge arrester is suspended above the conductor; The third installation scheme includes the installation method in which two parallel surge arresters of the structure of the second scheme are suspended on both sides of the tower above the conductor.

12. The installation system according to claim 7, characterized in that, The basic conditions of the ultra-high voltage AC transmission line include: The overvoltage characteristics of ultra-high voltage AC transmission lines, the terrain and topography of the towers, and the limitations of surge arrester installation.

13. A computer device, characterized in that, include: One or more processors; A processor is used to execute one or more programs; When the one or more programs are executed by the one or more processors, the method described in any one of claims 1-6 is implemented.

14. A computer-readable storage medium, characterized in that, It contains a computer program, which, when executed, implements the method as described in any one of claims 1-6.

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