WO2015078195A1

WO2015078195A1 - Live overhaul process for ± 500 kv double-loop dc power transmission line on same tower

Info

Publication number: WO2015078195A1
Application number: PCT/CN2014/083325
Authority: WO
Inventors: 余雷; 刘越; 汤正汉; 向文祥; 刘继承; 王星超
Original assignee: 国家电网公司; 国网湖北省电力公司检修公司
Priority date: 2013-11-27
Filing date: 2014-07-30
Publication date: 2015-06-04
Also published as: CN103618249A; CN103618249B

Abstract

A live overhaul process for a ± 500 kV double-loop DC power transmission line on the same tower. An operation method of entering equal potential comprises the steps of: after an equal potential worker and an earth potential worker carry insulated transmission ropes and climb to an earth wire peak and fasten safety belts, installing, by the equal potential worker and the earth potential worker, an insulated pulley and the insulated transmission ropes on the earth wire peak; transmitting, by a ground worker, an insulated flexible ladder and a hanging head of the insulated flexible ladder to the position of the earth potential worker; dismantling, by the earth potential worker, a damper of a working-side overhead earth wire, and reliably installing the hanging head of the insulated flexible ladder on the overhead earth wire; after checking the connection of various parts of screening clothing, the equal potential worker fastening an insulated protection rope, climbing to the insulated flexible ladder and fastening the safety belt to the insulated flexible ladder; and swinging, by the ground worker, the insulated flexible ladder using a tail rope of the insulated flexible ladder, and quickly reaching out for the wire to carry out potential transfer when the equal potential worker is about 0.5 m away from a live wire. The live overhaul process can improve the efficiency of line repairs.

Description

±500kV double-circuit DC transmission line on the same tower

The invention relates to the field of ultra-high voltage power transmission and transformation, in particular to a charging and repairing process for a ±500kV double-circuit direct current transmission line on the same tower. Background technique

The operation, maintenance and repair of transmission lines is an important means to master the operation of the power grid, to detect and deal with equipment defects in time, and to ensure the safe and stable operation of the line. Since the UHV grid is at the core of the operation of the national grid, the operation and overhaul of the EHV grid is of great significance for ensuring the safe, stable and reliable operation of the UHV grid and even the entire national grid.

The comprehensive transformation of Gehu DC is ± 500kV Genan Line (Linfeng Line) The same tower double-circuit DC transmission project is an innovative project for the development of DC transmission technology in the world. It is the first double-circuit DC transmission project in the same tower at home and abroad. The project is to transform the original Genan single-circuit line (capacity of 1200MW) into a double-circuit ±500kV capacity DC line (capacity of 2x3000MW). It is the implementation of the strong grid construction by the State Grid Corporation and the implementation of the national power transmission to the west. Another key project of the development strategy is to have a positive significance for further expanding the scale of the Three Gorges and Sichuan hydropower transmission, enhancing the liaison between Huazhong and East China, and building a strong national grid.

The 500kV double-circuit line on the same tower is a brand-new operation mode of the DC line. The line structure and window gap are quite different from other projects, especially the tower structure and the tensile-proof insulator type string assembly form. big change. Therefore, the traditional method of operation can not meet the needs of ± 500kV double-circuit DC line maintenance on the same tower. For maintenance and live work, the first step is to study a set of scientific methods of operation, including the way of operation and the process flow. The research on the maintenance of ± 500kV double-circuit DC line on the same tower, live working methods and working tools will be our urgent problems. The research results of this subject will fill the blank of the overhaul of ± 500kV double-circuit DC transmission line on the same tower and the development of live working tools and practical technology for live working. It is of great significance to create a ± 500kV double-circuit DC line maintenance on the same tower, improve line maintenance efficiency, and ensure the health of the equipment. Summary of the invention

In view of this, in order to overcome the deficiencies of the prior art, it is necessary to provide a double-circuit DC for the same tower of ± 500 kV. The electrification maintenance process of the transmission line.

A charging and repairing process for a ±500kV double-circuit DC transmission line on the same tower, the electrification maintenance process includes an operation method of entering an equipotential, and the operation method for entering the equipotential includes the following steps: the equipotential worker and the ground potential worker follow the dress code After wearing, carry the insulated transmission rope to the ground support to fasten the seat belt, and install the insulated pulley and the insulated transmission rope at the appropriate position on the working ground support; the ground worker transmits the insulation ladder and installs the insulation of the ladder control rope. The ladder is attached to the ground potential worker position; the ground potential worker removes the anti-vibration hammer of the working side overhead ground line, and then the ladder ladder is reliably installed on the overhead ground line, and the ladder hook control rope is installed; the equipotential worker checks the shielding After the parts are well connected, fasten the insulation protection rope, board the insulation ladder and attach the safety belt to the insulation ladder. If it is a tensile tower, the ground potential worker uses the ladder head control rope to drive the insulation ladder along the overhead space. The line is moved to the parallel of the tensile clamp. If it is a straight tower, the ground potential worker uses the ladder to control the rope. The edge ladder moves about 5m along the overhead ground line. The equipotential workers descend along the insulation ladder until the shoulders are flush with the upper sub-wires. The ground workers use the insulated ladder tail rope to swing the insulation ladder. The equipotential workers are about 0.5 from the live conductor. When you are at m, quickly reach and hold the wire for potential transfer.

In at least one of the embodiments, in the operation method of entering the equipotential, the equipotential worker enters the potential and fastens the seat belt, and determines whether to release the insulation protection rope according to the operation requirement, and the equipotential worker checks and inspects the parts of the shielding suit. After the connection is good, board the insulation ladder and attach the seat belt to the insulation ladder.

In at least one of the embodiments, the dress code includes an equipotential worker wearing a full set of rhinoceros garments and a shielded garment wearing a flame retardant garment, the rhinoceros garment including a rhinoceros cap, a shielded garment, a shielding glove, and a shielding sock. , shielding shoes and rhinoceros masks, ground potential workers must wear a full set of static protective clothing and conductive shoes.

In at least one of the embodiments, after the electrification maintenance work is completed, the equipotential is exited according to the following steps: After the equipotential worker checks and checks that the parts of the shielding suit are well connected, the boarding station is placed on the insulating ladder and the seat belt is attached to the insulating ladder. The equipotential worker loosens the wire and quickly withdraws the arm. The ground worker uses the insulated ladder tail rope to swing the insulation ladder, and the equipotential worker exits the equipotential; the ground potential worker uses the insulated ladder control rope to drive the insulation ladder along the overhead ground at the ground support. The line is moved to the crossarm, the equipotential worker unfastens the seat belt attached to the insulating ladder, climbs up the cross arm and fastens the seat belt; the ground potential worker cooperates with the ground worker to remove all the tools and restore the ground line defense. Installation of the vibrating hammer; After the equipotential workers and the ground potential workers inspect the unretained objects on the tower, carry the insulated transmission rope to the lower tower.

In at least one of the embodiments, the electrification overhaul process includes a method of replacing a linear double "V" insulator string, a hard-turn double "L" insulator string, the replacement of a straight double "V" insulator string, a hard turn double" The operation method of the L" insulator string includes the following steps: Retaining the construction hole at the hanging point of the insulator string or the tower of the main material at the hanging point The upper fulcrum, the special clamp for the cross-arm of the pole tower is installed, and the large-knife card is installed by the side fulcrum of the wire side of the two-layer board of the wire-side tool; the wire-drawing device and the high-strength insulating tie rod are connected with the special fixture on the tower to form the insulator string. Mechanical load transfer system; using the contact point of the card back and the two plates of the large knife card as a fulcrum, and dividing the large knife card into the working arm and the operating arm, operating the wire lifting device to carry out the wire movement of the small distance, driving the large knife card operating arm to rotate The action arm transfers the load on the insulator string, and transfers the mechanical load of the insulative insulator string to the wire lifting system to realize the inspection and replacement of the insulator string.

In at least one of the embodiments, in the method of replacing the linear double "V" insulator string and the hard-turn double "L" insulator string, the wire lifting device includes a mechanical screw and a hydraulic screw.

In at least one of the embodiments, the electrification overhaul process includes a method of replacing a tensile-resistance insulator, the method of replacing the tensile-resistor insulator comprising the following steps: after entering the potential, two equipotential workers站Standing on the adjacent porcelain rod insulators in a back-to-back manner, using the traction plate and the parallel hanging plate as the fulcrum to install the cross-arm side-end special card, using the porcelain rod insulator steel cap as the fulcrum to install the closed card card The hydraulic screw assembly is used to connect the tensile special card and the closed card to form the tight line system, and then the tripod assembly is installed for transferring the tool and the insulator; the front card of the closed card is separately installed by using the front and rear rod insulator steel cap as a fulcrum After the card, the front and rear cards of the closed card are connected by a hydraulic screw assembly to form a tight line system, and then the tripod assembly is installed for transferring the tool and the insulator; and the closed card front card is used by the insulator steel cap; The joint plate side wing type card is installed on the joint plate, and the hydraulic screw rod assembly is used to connect the closed type card and the wire side wing type card to form a tight line system, and then install three The angle bracket assembly is used to transport the tool and the insulator; the hydraulic screw is tightened to tighten the wire system, and the mechanical load on the inspected porcelain rod insulator is transferred to realize the replacement and maintenance of the insulator.

The charging and repairing process of the ±500kV double-circuit direct current transmission line of the same tower of the present invention is the first research project of the live working application technology of the ultra-high voltage double-circuit direct current transmission line on the same tower at home and abroad, and the characteristics of the ±500kV double-circuit direct current transmission line on the same tower The research has realized the completion of the project research work and the application of the research results, filling the gaps in the field of ultra-high voltage DC live working and live maintenance application technology at home and abroad. DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic illustration of a method for entering an equipotential in a live overhaul process of a ±500 kV homotaxial double-circuit DC transmission line in accordance with a preferred embodiment of the present invention.

Figure 2 is a schematic diagram of the "positive wire drawing" method of replacing the insulator string.

3A and 3B are respectively used to replace the linear double "V" insulator string and the hard-turn double "L" insulator string. The main view and top view of the large knife card used.

Figure 4 is a schematic diagram of the operation of replacing the linear double "V" insulator string and the hard-turn double "L" insulator string with the large knife card in Figure 3.

5A and 5B are structural schematic views of the hydraulic closed card front and rear cards respectively used in the method of replacing the tensile-resistance insulator.

6A and 6B are a partial cross-sectional view and a partial cross-sectional view of another cross-angle side airfoil card used in the method of replacing the tensile-resistance insulator.

Fig. 7 is a structural schematic view of a wire side airfoil card used in the method of replacing the tensile-resistance insulator. detailed description

In order to better understand the present invention, the invention will be described in detail below with reference to the drawings and specific examples.

Before the detailed introduction of the technical solution of the present invention, the theoretical basis of the project research is first stated:

(1) According to the design unit of Zhongnan Electric Power Design Institute, the tower structure of the ± 500kV DC double-circuit line on the same tower, the insulator string type, the fitting form of the gold fittings, the layout of the grounding line, and the mechanical load level and air gap form of the line;

(2) According to the analysis and calculation of the overvoltage level of the 500kV double-circuit DC transmission line on the same tower of the State Grid Electric Power Research Institute and the gap test of the live operation of the 500kV double-circuit DC line on the same tower, the proposed ultra-high voltage double-circuit on the same tower The theoretical value of the insulation fit of the live working such as the minimum safe distance of the DC line live working, the minimum combined clearance, the effective insulation length of the tool and the number of effective insulators;

(3) According to the new version of “Safety Regulations” of State Grid Corporation of 2009 and the “Technical Guidelines for Live Working of ±500kV DC Transmission Lines”, the minimum safety distance of live working, the minimum combined clearance, the effective insulation length of the tool and the number of effective insulators, etc. Insulation matching theoretical value of live working;

(4) According to the State Grid Electric Power Research Institute "Study on the live operation of the 500kV double-circuit DC line on the same tower" (high voltage technology, Vol. 36, No. 2, February 28, 2010), the minimum safety of live working is calculated. Test values such as distance and minimum combined clearance.

± 500kV Genan (Linfeng Line) The same tower double-circuit DC transmission line project (ie, Sanhu 2nd DC transmission project) As the first ultra-high voltage DC transmission project in the same tower in China, its transmission line maintenance and live working work It has not been carried out at home and abroad, and the development of its operation technology and application tools needs to be solved. ± 500kV Genan Line (Linfeng Line) The overall structure of the double-circuit DC transmission line of the same tower is composed of a tower, an insulator, a grounding wire and a connecting fitting. It adds a layer of crossbar to the single-circuit UHV DC line tower to bear another One line back. Based on the in-depth digestion of the research results of the 500kV twin-circuit DC line live working technology of the State Grid Electric Power Academy, the design parameters of the ±500kV double-circuit DC line on the same tower were carefully analyzed, and the voltage level of ±500kV was fully discussed. The difference and particularity of live working are studied. The overhaul operation of the double-circuit ultra-high voltage DC line on the same tower, the operation method and operation process of the live working, and the insulation coordination parameters of the live working of the ±500kV double-circuit DC line on the same tower are determined. The method of potential and the process flow for replacing the insulator have been thoroughly studied to verify the specific measures for protection of live workers.

First, entering the equipotential operation is the basic operation mode for live working, and is the basis for the realization of other live working items. Firstly, it breaks through the difficulty of entering the potential. According to the design structure of the ±500kV double-circuit DC transmission line of the same tower, the window window size and the gap form and air gap level required by the operation, the traditional cross-supporting ladder is vertically entered into the equipotential. The research and design of the working method of the horizontal swinging into the equipotential of the flying ladder.

The following is a detailed description of the working method in which the flying ladder is horizontally placed into the equipotential.

The tower requires two workers on the tower, one of which is an equipotential electrician and the other is a tower-ground potential electrician. Before entering the equipotential, equipotential workers must wear a full set of shielding clothing, including caps, underwear, gloves, socks and shoes, and wear a shielded mask. In addition, flame-retardant underwear should also be worn inside the shielded clothing. . Ground potential workers must wear full static protective clothing and conductive shoes.

After the equipotential workers and the ground potential workers are dressed according to the above dress code, follow the steps below to enter the equipotential level:

(1) Equipotential workers and ground potential workers carry insulated transmission ropes to the ground support, fasten the seat belts, and install the insulated pulleys and insulated transmission ropes at appropriate positions on the working ground support.

(2) The ground workers pass the insulation ladder and the insulated ladder head (installed the ladder control rope) to the ground potential worker position.

(3) The ground potential worker removes the anti-vibration hammer of the working side overhead ground wire (if the ground wire is insulated overhead ground wire, the insulated ground wire should be reliably grounded on the non-working side before work), and then the ladder hanger head is reliably installed. On the overhead ground line, install the ladder hanging head control rope.

(4) After equipotential workers check that the parts of the shielding suit are well connected, fasten the insulation protection rope, board the insulation ladder and attach the safety belt to the insulation ladder. If it is a tensile tower, the ground potential worker will use the ladder to control the rope to insulate. Move the ladder along the overhead ground wire to the parallel of the tension clamp. In the case of a linear tower, the ground potential worker uses the ladder head control rope to move the insulation ladder along the overhead ground line by about 5 m, and the equipotential worker descends along the insulation ladder until the shoulder is flush with the upper sub-wire.

(5) The ground workers use the insulated ladder tail rope to swing the insulation ladder. When the equipotential workers are about 0.5m away from the live conductor, they quickly reach and hold the conductor for potential transfer.

(6) When the equipotential worker enters the potential, fasten the seat belt and release the insulation protection rope according to the operation. After entering the equipotential, the live maintenance of the ±500kV double-circuit DC transmission line on the same tower can be carried out. For example, live replacement wire anti-vibration hammer, live replacement of tension-resistant wire side fittings, live replacement adjustment wire spacers, and live replacement insulators. The inspection process for some of the components will be described in detail below.

After the live maintenance work is completed, the equipotential worker can exit the equipotential as follows:

(1) Equipotential workers check that all parts of the shielding suit are well connected, board the insulation ladder and attach the seat belt to the insulating ladder (hold the insulated ladder in one hand and hold the wire in one arm).

(2) After the approval of the person in charge of the work, the equipotential worker loosens the wire and quickly withdraws the arm. The ground worker uses the insulated ladder tail rope to swing the insulation ladder, and the equipotential worker exits the equipotential.

(3) The ground potential worker uses the insulated ladder control rope to move the insulation ladder along the overhead ground line to the crossarm at the ground support. Equipotential workers unfasten the seat belt attached to the insulated ladder, climb up the crossbar, and fasten the seat belt.

(4) The ground potential worker cooperates with the ground electrician to remove all the tools and restore the installation of the ground anti-vibration hammer (if any, the grounding wire is finally removed).

(5) After the equipotential workers and the ground potential workers inspect the unretained objects on the tower, they carry the insulated transmission ropes to the lower tower.

According to the above method of entering and exiting the potential, the components on the 500kV double-circuit DC transmission line on the same tower can be inspected. Since there are many work items in the 500kV double-circuit DC transmission line on the same tower, the repair methods of some components are the same as the previous operation methods, so I will not comment here. In the following, the key operation methods of the electrified maintenance process such as the live replacement insulator will be described in detail.

First, the operation method of replacing the linear double "V" insulator string and the hard-turn double "L" insulator string with "Leverage principle micro-lifting method" will be described.

± 500kV Genan Line (Linfeng Line) The design of the double-circuit line of the same tower, the line of all the linear towers with double "V" insulator strings and hard turrets with double "L" insulator strings. When there is a defect in the insulator string component, the mechanical load of the insulator string is generally transferred by "positive wire lifting", and the insulator string is repaired and replaced. Please refer to Figure 2, The so-called "positive lifting" method mainly refers to the use of a construction hole (or main material) directly above the wire joint plate as a fulcrum on the tower, and a special jig (or connecting tool) for the cross-arm of the tower is connected. A wire lifting device (mechanical screw or hydraulic screw), a high-strength insulated tie rod, and a four-split wire feeder are connected to the wire to form a mechanical load transfer system of the insulator string. The load transfer system is tightened by operating the mechanical screw or the hydraulic screw, and the wire is slowly lifted, so that the mechanical load of the repaired insulator string is transferred to the wire-raising system to realize the maintenance of the insulator string. However, the mechanical load of the wire-lifting tool of the "positive wire-drawing" operation mode may cause the horizontal direction of the insulator-side insulator string to be weakened, thereby causing the wire to be offset in the opposite direction. In the case of a defective insulator string, it is necessary to use a measure to prevent the lateral displacement of the conductor when the insulator string is reset, so as to avoid difficulty in repairing the insulator string.

Therefore, according to the structural characteristics of the ± 500kV double-circuit DC transmission line design of the same tower, in this project, the linear double "V" insulator string and the hard-turn double "L" insulator string are replaced with a large knife card and the "lever principle" is used. Linework method "Transfers the mechanical load of the insulator string. The structure of the large knife card is shown in Figures 3A and 3B. Referring to Figure 4, one end of the large knife card is a hook that matches the threaded screw of the inverted triangle, and the other end is the opening for the external screw. A platform is provided on the waist connecting the hook and the opening to contact the bottom side of the inverted triangular joint plate. The hook end of the large knife card has a bayonet that is set on both sides of the inverted triangle two-plate, and the root platform of the bayonet is in contact with the bottom side of the inverted triangle two-plate. A through hole for mounting a knurled screw is provided on both sides of the opening of the large knife card, and the through hole is used for the external screw. The large knife card also has a groove at the waist. If it is necessary to carry out pre-maintenance and overhaul of the metal fitting on one side of the triangular joint board, firstly, the bayonet card of the large knife card is clamped on the bottom of the side of the inverted triangle two-piece board, and the hook is hooked in the inverted triangle. The threaded screw of the center of the two-plate center, the root platform of the bayonet supports the end of the pre-maintenance and overhaul of the inverted triangle two-piece board, so that the other end of the side of the inverted triangle-connected board is the fulcrum, and the open end is the end of the lever . Then, the screw rod is externally connected to the open end, and the force is applied to the open end by manually adjusting the screw rod, so that the end of the lever, that is, the opening, only needs to exert a small force to be used on the pre-maintenance and overhaul end of the triangular joint plate. The heavy load is removed.

具体 Use the big knife card and use the "lever principle micro-lifting line operation method" to replace the linear double "V" insulator string, hard turn double "L" insulator string operation method as follows:

(1) Use the insulator hole to reserve the construction hole (or the main material at the hanging point) as the fulcrum on the tower of the tool, install the cross-clamp of the pole tower, and use the wire side two-plate to make the wire side fulcrum of the tool to install the large knife. Card

(2) The mechanical load transfer system that constitutes the insulator string is connected by a wire lifting device (mechanical screw or hydraulic wire) and a high-strength insulating tie rod to the cross-arm clamp on the tower;

(3) using the contact of the card back and the second board of the large knife card as a fulcrum, and dividing the large knife card into the working arm and the operating arm, The wire lifting device is operated to perform a small-distance wire-lifting displacement, and the large-cutter card operating arm is driven to rotate, and the belt-operating arm transfers the load on the insulator string, so that the mechanical load of the insulative insulator string is transferred to the wire-drawing system to realize the maintenance of the insulator string.

In the above process, the working load of the double "V" insulator string and the hard-turn double "L" insulator string card is 50KN. The above process utilizes the principle of leverage, and the operation of the wire lifting device for the displacement of the wire at a small distance can drive the rotation of the large knife operation arm, and the action arm can transfer the load on the insulator string, and the double "V" insulator can be replaced conveniently and quickly. String, hard turn double "L" insulator string.

Finally, the method of replacing the tensile insulator will be described in detail.

The replacement of tensile insulators and insulator strings is a routine project for maintenance and live working of transmission lines, and is also a daily work for maintenance and repair of transmission lines. In the general maintenance process, the tensile insulators and the insulator strings are replaced by a conventional one. The replacement of the tensile insulator method and the improved spinning method are used to replace the tensile insulator method. The bottle holder method is to install a tight line system at both ends of the repair insulator string, and place a bottle holder under the tightness, tighten the wire system to protect the insulator string from the wire tension, and then disconnect the insulator string and the wire and the cross arm. Link, then use the insulated sling to place the repair insulator string on the ground with the bottle holder, and then complete the maintenance work in the reverse work process. The spinning method is to first loosen the insulator with the insulator string tension adjuster, then use the traction system to pull the insulator to disengage the wire side porcelain bottle, and rotate the porcelain bottle string to the vertical position along the tower suspension point before placing it on the ground. The reverse work process completes the maintenance work.

± 500kV Genan Line (Linfeng Line) The double-circuit line insulator string on the same tower is designed as a horizontal glass insulator or a ceramic rod insulator. Among them, the glass string is the smallest (light pollution area) 40 pieces, the length is 10.737 meters, the single string weight is 0.73T, the largest (heavy pollution area) 57 pieces, the length is 14.222 meters, the single string weight is about 0.97T; the porcelain rod insulator The string consists of 7 pieces, which is 14.772 meters long and weighs about 0.95T in a single string. Although the whole series of replacement repair methods, the construction of the construction equipment and the actual operation of the field using the traditional tensile insulator string replacement method are technically achievable, but as a routine maintenance, especially the way of taking live work It is still quite difficult to carry out maintenance. Therefore, the project is based on the double-strength design of the ±500kV double-circuit DC line project and the insulation form used in the same project. The single-replacement operation mode is selected to focus on the design of the replaced ceramic rod insulator with short-zero value. In order to achieve the purpose of replacement. The specific operation process is as follows:

(1) After entering the potential, the two equipotential workers stand in the "back to back" mode on the adjacent rod insulators, using the traction plate (QY-42S type) and the parallel hanging plate (P-42S) as the fulcrum installation. The cross-arm side is resistant to the card (as shown in Figure 6), using a porcelain rod insulator steel cap as a fulcrum to install a closed card rear card (as shown in Figure 5), using a hydraulic screw assembly to connect the tensile card and The closed card forms a tight line system, and then the tripod assembly is mounted for the transfer of tools and insulators; (2) Using the front and rear rod insulator steel caps as the fulcrum to install the front and rear cards of the closed card respectively (as shown in Figure 5), and connect the front and rear cards of the closed card with the hydraulic screw assembly to form a tight line. System, then install a tripod assembly for transporting tools and insulators;

(3) Install the closed card front card with the insulator steel cap as the fulcrum, and use the joint plate (LS-84600500S type) as the fulcrum to install the wire-side special airfoil card (as shown in Figure 7), and connect it with the hydraulic screw assembly. The card and the wire-side special airfoil card form a tight wire system, and then the tripod assembly is installed for conveying the tool and the insulator;

(4) Operate the hydraulic screw to tighten the tight line system, transfer the mechanical load on the inspected porcelain rod insulator, and replace and repair the insulator.

Single-piece replacement process for ordinary insulators: Use the cross-arm side plate as the fulcrum, install the cross-arm side-resistant special card, use the insulator steel cap as the fulcrum, install the insulator closed card front card, and connect the tensile-resistant special card with the hydraulic screw. And the closed card form a tight line system; using the insulator steel cap as the fulcrum, respectively installing the front card and the rear card of the insulator closed card, and connecting the front card and the rear card of the insulator closed card with the hydraulic screw to form a tight line system; Insulator steel cap as the fulcrum, install the insulator closed card rear card, use the wire side joint plate ^ t fulcrum, install the wire side turn airfoil card, use the hydraulic screw to connect the closed card and the wire side turn with the airfoil card The wire system, operating the hydraulic screw to tighten the tight line system, transferring the mechanical load on the repaired insulator to achieve the replacement and maintenance of the insulator. Through the above process, the single-piece replacement of the tensile insulator string can be realized, and the workability of the tensile insulator string as a routine maintenance is ensured.

In summary, the charging and repairing process of the ±500kV double-circuit DC transmission line of the same tower of the present invention is the first research project of the first 500kV double-circuit live working application on the same tower at home and abroad, the completion of the project research work and the application of the research results. It fills the gaps in the field of live working and live maintenance application of ± 500kV double-circuit DC transmission lines on the same tower at home and abroad. The specific operation method in the charging and repairing process of the ±500kV double-circuit DC transmission line of the same tower of the present invention covers the inspection and repair of the ±500kV double-circuit DC transmission line on the same tower, and the routine maintenance work of the live working, wherein the porcelain rod insulator replacement tool, The single-short-circuit replacement method for large-tonnage combined hydraulic screw is applied to live working, especially to the ±500kV double-circuit line operation method in the same tower. It is a major breakthrough in the field of live working application technology. The invention has been described with reference to a few specific embodiments of the invention, which are not to be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the inventive concept, and these are all within the scope of the present invention. Therefore, the scope of the invention should be determined by the appended claims.

Claims

claims

1. A live maintenance process for a ±500kV double-circuit DC transmission line on the same tower. The live maintenance process includes an operation method of entering equal potential. The operation method of entering equal potential includes the following steps:

After the equipotential workers and ground potential workers have finished dressing in accordance with the dress code, they carry the insulating transfer rope up the tower to the ground wire support and fasten their safety belts, and install the insulating pulley and the insulating transfer rope at the appropriate position of the working ground wire support;

The workers on the ground transfer the insulated ladder and the insulated ladder hanging head with the ladder control rope installed to the ground potential worker's position; the ground potential worker removes the anti-vibration hammer of the overhead ground wire on the working side, and then reliably installs the ladder hanging head on the overhead ground wire, and Install the ladder hanging head control rope;

After the equipotential workers check that all parts of the shielding suit are well connected, they fasten the insulating protective rope, climb onto the insulating ladder and stand up, and tie the safety belt to the insulating ladder. If it is a tension pole tower, the ground potential worker uses the ladder hanging head to control the rope. Move the insulated ladder along the overhead ground wire to the parallel point of the tension clamp. If it is a straight pole tower, the ground potential worker will use the ladder hanging head control rope to move the insulated ladder outward about 5m along the overhead ground wire. The equipotential worker will go down the insulated ladder to Stop when the shoulder is flush with the upper sub-wire;

Ground workers use the tail rope of the insulated ladder to swing the insulated ladder. When the equipotential worker is about 0.5m away from the live wire, he quickly reaches out to hold the wire to perform potential transfer.

2. The live maintenance process of ±500kV double-circuit DC transmission lines on the same tower according to claim 1, characterized in that: in the operation method of entering the equipotential, the equipotential workers fasten their safety belts after entering the potential, and according to The operation needs to determine whether to remove the insulating protective rope. After the potential equalization worker checks that all parts of the shielding suit are well connected, he should stand on the insulating ladder and tie the safety belt to the insulating ladder.

3. The live maintenance process of ±500kV double-circuit DC transmission lines on the same tower according to claim 1, characterized in that: the dress code includes: equipotential workers wear a full set of protective clothing and wear flame-retardant underwear under the protective clothing, The shielding clothing includes a shielding hat, shielding clothes and pants, shielding gloves, shielding socks, shielding shoes and a shielding mask. Ground potential workers must wear a full set of electrostatic protective clothing and conductive shoes.

4. The ±500kV same-tower double-circuit DC transmission line live maintenance process according to claim 1, characterized by: After the live maintenance work is completed, follow the following steps to exit equipotential:

After the potential equalization worker checks that all parts of the shielding suit are well connected, he climbs onto the insulating ladder and stands up, and fastens the safety belt to the insulating ladder;

The equipotential worker loosens the wire and retracts his arm quickly. The ground worker uses the tail rope of the insulated ladder to swing the insulated ladder, and the equipotential worker exits the equipotential level;

The ground potential worker uses the insulated ladder control rope at the ground wire support to move the insulated ladder along the overhead ground wire to the cross arm. The equipotential worker unties the safety belt fastened to the insulated ladder, climbs up and onto the cross arm, and fastens it. safety belt;

Ground potential workers cooperate with ground workers to remove all tools and restore the installation of ground wire anti-vibration hammers;

After checking that there is nothing left on the tower, the equipotential workers and ground potential workers carry the insulating transfer rope down the tower.

5. The live maintenance process of the taxi 500kV double-circuit DC transmission line on the same tower according to any one of claims 1 to 5, characterized in that the live maintenance process includes replacing the linear double "V" insulator string, hard-rotating the double The operation method of "L" insulator string, the operation method of replacing the straight double "V" insulator string and the hard-rotating double "L" insulator string includes the following steps:

Use the construction holes reserved at the insulator string hanging points or the main material at the hanging points to serve as the fulcrum on the tower for tools, install special clamps for the pole tower cross arms, and use the conductor side fulcrum of the conductor side double plate to install the large knife clamp;

The mechanical load transfer system of the insulator string is formed by connecting the wire lifting device and high-strength insulating tie rods to the special clamps on the tower;

Use the contact point between the card back of the large knife card and the two-joint plate as the fulcrum, and divide the large knife card into an action arm and an operating arm. Operate the thread lifting device to perform a small distance lifting displacement, drive the operating arm of the large knife card to rotate, and drive the action arm to transfer. The load on the insulator string transfers the mechanical load of the insulator string to be repaired to the wire lifting system to realize the maintenance and replacement of the insulator string.

6. The live maintenance process of ±500kV double-circuit DC transmission lines on the same tower according to claim 6, characterized in that: in the operation method of replacing linear double "V" insulator strings and hard-rotating double "L" insulator strings , the thread lifting device includes a mechanical screw rod and a hydraulic screw rod.

7. The live maintenance process of the ±500kV double-circuit DC transmission line on the same tower according to any one of claims 1 to 5, characterized in that the live maintenance process includes the operation method of replacing the tension-resistant porcelain rod insulator, so replacement The operation method of tension-resistant porcelain rod insulators includes the following steps:

After entering the potential, two equipotential workers stood back-to-back on the adjacent porcelain rod insulators. They used the traction plate and the parallel hanging plate as fulcrums to install the special tensile card on the side of the cross arm, and used the porcelain rod insulator steel. The cap is used as a fulcrum to install the closed card and the rear card, and a hydraulic screw assembly is used to connect the tension-resistant special card and the closed card to form a tight line system, and then a tripod assembly is installed for conveying tools and insulators;

Use the front and rear rod insulator steel caps as fulcrums to install the front and rear clamps of the closed card respectively. Use the hydraulic screw assembly to connect the front and rear clamps of the closed card to form a tight line system. Then install the tripod assembly for conveying tools. and insulators; use the insulator steel cap as a fulcrum to install the closed card front card, use the connecting plate as a fulcrum to install the conductor side wing card, use a hydraulic screw assembly to connect the closed card and conductor side wing card to form a tight line system, and then install the tripod Components are used for conveying tools and insulators;

Operate the hydraulic screw rod to tighten the cable system, transfer the mechanical load on the porcelain rod insulator to be repaired, and realize the replacement and maintenance of the insulator.