178results about "Arrangements for earthing wires/cables" patented technology

A stringing messenger clamp for use in overhead transmission and distribution systems and method of installing a messenger cable is provided. The stringing messenger clamp includes a bracket and an assembly body supported by the bracket, wherein the assembly body has a cable channel sized to receive a portion of a messenger cable. An assembly clamp is movable with respect to the assembly body and closable upon the cable channel. When the assembly clamp is in a closed position, it retains in place the portion of the messenger cable within the cable channel.

The invention relates to a compound material pole tower. A main body of the pole tower adopts a compound material; a main connecting part adopts compound material or galvanized steel; a lead cross armadopts a compound insulator; a ground lead cross arm adopts galvanized steel; a downlead cross arm adopts galvanized steel adopts galvanized steel; a grounding downlead adopts wires and bars; the upper end of the grounding downlead is fixed on the grounding wire cross arm, is led from leads at the outside of one side or two sides of the pole tower, is fixed on the downlead cross arm to lead the grounding downlead and the lead to keep fixed distance, and is grounded from the downlead cross arm along the tower body. Compared with the conventional 110kV iron tower, the compound material pole tower greatly increases phase-earth and interphase air gaps and insulating creepage distance of a tower head, greatly improves pollution flashover resistance, ice flashover resistance, windage yaw prevention and lightning-resistant level, also can compress the size of the tower head, and has the advantages of reducing the cost as well as expenses for transportation, installation and maintenance of the pole tower body and simultaneously reducing the width of a line corridor.

The invention discloses a grounding method for a composite insulating pole tower of a power transmission line and a pole tower thereof. The pole tower main body adopts a composite tube, a conductor cross arm adopts a composite insulator, a ground wire cross arm adopts a metal conductor, a grounding down-lead adopts a metal wire or a tube or a bar, the grounding down-lead is suspended from the middle of the tube and is led down to be grounded, the ground wire cross arm and the conductor cross arm are provided with metal electrodes, and the proper part of the pole tower is perforated for arranging the grounding down-lead to lead out the electrodes; and the air gap distance between the ground wire side electrode and the conductor side electrode and the air gap distance between the leading-out electrode of the grounding down-lead and the conductor can be determined according to the lightning protection requirement. The grounding mode of the composite pole tower effectively utilizes the insulating property of a composite pole, can improve the pollution flashover and ice flashover resistance, wind deflection prevention and lightning protection level of the line, can also compress the size of a tower head, and has the advantages of reducing the manufacturing cost and the transportation, assembly and maintenance expenses of the pole tower main body and reducing corridor width of the line at the same time.

The invention relates to a tower ground wire bridge crossing device for a power transmission line inspection robot, which includes two ground wires connected on both sides of the tower, and a bridge is connected between the two ground wires on the outside of the tower, and the two bridges cross the bridge. The ends are respectively connected to the two ground wires through two bridge clamps. Each bridge clamp includes a bridge sleeve and a positioning channel on one side of the bridge sleeve that is suitable for the passage of the ground wire. One end of the bridge is along the One end of the bridge sleeve is pierced and fixed, and the other end of the bridge sleeve extends to the ground and forms a transition connection with the ground; the invention can effectively solve the problem that the robot rolling on the ground passes through the tower. The structure is simple, the construction is convenient, and no damage or modification is made to the pole tower or line fittings; and the bridge is made of flexible track materials, which can be adapted to various types of pole towers.

The invention provides a method for replacing an optical fiber composite overhead ground wire or a common overhead ground wire without power cut. The method comprises the following steps of: hanging a plurality of suspension pulleys and a wiring tractor on an old ground wire between two iron towers; connecting the suspension pulleys and an iron tower at one end, connecting every two adjacent suspension pulleys and connecting the wiring tractor and the suspension pulleys by a connection rope fixedly with an interval of between 15 and 20 meters; unwinding a new ground wire from a wire unwinding drum which is arranged on the ground, wherein after passing through the top of the iron tower at one end, the new ground wire passes through a hole on the lower part of each suspension pulley and is connected together with an insulating rope which is arranged on the wiring tractor by a clamp; starting the wiring tractor so as to draw the new ground wire to the iron tower at the other end; when the wiring tractor reaches the top of the iron tower at the other end, taking the old ground wire down and arranging the old ground wire on pulleys which are arranged on the iron towers at two ends; after stretching the new ground wire to specified sag, connecting the new ground wire and the iron tower and fixing the connection rope on the iron tower at the other end; loosening the old ground wire so as ensure that the positions of the old and new ground wires are exchanged; drawing the old ground wire back by a wire winding drum which is arranged on the ground, and demounting the connection rope, the insulating rope, the suspension pulleys and the wiring tractor at the same time; and precisely adjusting the sag of the new ground wire, arranging accessories, positioning and strengthening. By the method, sags of the new and old ground wires can be controlled conveniently to ensure that the new ground wire and the old ground wire do not contact a power line.

The invention discloses an optical unit direct leading-down structure of an OPPC (Optical Phase Conductor) and a construction method of the optical unit direct leading-down structure. The optical unit direct leading-down structure is provided with an OPPC optical cable (1), a pre-twisted wire assembly (3), a first connection fitting (4), a second connection fitting (6), an insulator string (7) and an optical connection jumper (8) and is also provided with an optical unit leading-out connector (2). By the structure, a plastic pipe optical unit of the OPPC optical cable hung at a high altitude can be separated and directly lead down, and moreover, the structure is suitably used for the OPPC optical cable of which the plastic pipe optical unit is arranged at an arbitrary position in the OPPC optical cable. By the construction method, connection between the OPPC optical cable and the optical unit leading-out connector and connection and installation of the pre-twisted wire assembly, the first connection fitting, a remaining cable rack, the second connection fitting and the insulator string can be completed on the ground, the OPPC optical cable is pulled to a high altitude and then is connected to a cross arm of an iron tower or a telegraph pole after winding of a remaining cable segment, and finally, the plastic pipe optical unit is directly lead down. The construction method has the advantages of simplicity and convenience in construction.

The invention relates to a power transmission line and discloses a method for aerial earth wire lead-down connection and earth wire assembly. The method comprises the following steps that: material for aerial earth wire lead-down connection is selected; The assembling method of aerial earth wire lead-down connection is that: steel stranded wires along a concrete pole body are bundled and fixed on the concrete pole body by steel wires; the steel stranded wires runs upwards through a guide anchor ear and a steel crossarm, then run upwards through a diagonal draw bar, a ground anchor ear, a pole top and a U-shaped bolt; a parallel groove clamp is used to fasten lead-down wires on the aerial earth wires; two earth wires with the prescribed length are welded into one; two ends of round steel are intensively welded with galvanized earth wire tips; a earth wire groove is dug to be of a U shape; firstly, the earth wires are buried near a pole tower tightly, then extend along the U-shaped earth wire groove and are buried to form a U-shaped earth wire; a resistance value of the earth wires is detected; if the same stable value which meets the design stipulation is obtained, the earth wires can be put into use. The method for aerial earth wire lead-down connection and earth wire assembly has convenient operation, reliable connection and low cost of construction and detection.

The invention relates to an insulated residual cable stand and mainly used in optical communication field in an optical fiber composite overhead ground wire (OPGW) high-voltage transmission line. The insulated residual cable stand is characterized by comprising a residual cable stand disc, a first steel belt hoop fixing device, a second steel belt hoop fixing device, and an insulating device. The first steel belt hoop fixing device and the second steel belt hoop fixing device are in insulated connection with the residual cable stand disc and have same structure. Each of the first steel belt hoop fixing device and the second steel belt hoop fixing device has a steel belt hoop, an M iron plate, and a fixing plate. The M iron plate is in an M shape and both ends of the M iron plate are fixed to the fixing plate. Both side surfaces of the M iron plate are provided with steel belt passing holes. The steel belt of the steel belt hoop passes through the steel belt passing holes on both side surfaces of the M iron plate. The insulating device comprises an insulated sleeve, an insulated plug, and a fixing bolt. The insulated residual cable stand has a reliable insulating property, may adapt to the requirements of different rod diameters, and can be well and stably fixed to an electric pole.

The present invention is oriented to solving existing problems in the ground systems of aerial networks of electric energy distribution, providing a pole with an incorporated ground system. Said pole has a ground lead embedded in its structure, and two connection terminal boards fitted in the upper and lower sections. This ground system completely avoids the subtraction of the lead, is effective in the grounding and ensures the efficient performance of the electrical distribution system by guaranteeing an effective connection to the ground system with operation, protection and control elements that are installed in the distribution network.

The invention relates to a tower arrangement structure, and in particular relates to a tower arrangement structure at a cable terminal. The tower arrangement structure is used for improving the safety of the cable terminal, belonging to the technical field of electrical safety. The structure comprises a line tower and a cable terminal tower at one side of the line tower, wherein the cable terminal tower is provided with a mounting plate which is fixedly provided with an arrester and a cable terminal joint; the distance L between the cable terminal joint and the arrester is 1-1.5m, thus reducing the field intensity distribution on the cable terminal joint and decreasing the occupied land resources. The structure is good in effect and stable in operation, and is safe and reliable.

The invention discloses an overhead ground wire configuration method of a power distribution network. The method comprises the steps of arranging a main overhead ground wire above a target power distribution line area; determining an easily-hit road section of the target distribution line area, wherein the easy-to-strike road section represents a line section which is easy to suffer from lightningstroke or has a lightning stroke fault; determining an easy-to-hit tower located in the easy-to-hit road section, wherein the easy-to-strike pole tower represents a line pole tower which is easy to suffer from lightning stroke or has a lightning stroke fault; additionally arranging a shunt overhead ground wire in a direction different from that of the main overhead ground wire at the position ofthe easy-to-strike tower. The invention further discloses the corresponding overhead ground wire of the power distribution network. By adopting the embodiment of the invention, the lightning current value passing through the main overhead ground wire can be effectively reduced, so that the damage probability of the distribution network transformer is reduced, the lightning protection performance of the distribution network transformer is improved, and the power supply safety and reliability of the distribution network are improved.

The invention provides a lightning conductor high-voltage power-obtaining system and a power-obtaining method, wherein the power is uninterruptedly obtained from a high-voltage line to power up power equipment on the power transmission line. The lightning conductor high-voltage power-obtaining system comprises a first tower pole and a second power pole, wherein the spacing between the two power poles is 2.5-3.5 km. The first tower pole and the second power pole are connected with a first ground wire and a second ground wire. A gap insulator is arranged between the first ground wire and the first and second tower poles. The first ground wire is connected with the second tower pole via a first grounding drainage thread. The first tower pole, the first ground wire, the second tower pole and the second ground wire together form a loop. An electromagnetic induction power-obtaining supply is arranged in the loop. According to the technical scheme of the invention, the power is obtained from a lightning conductor by the electromagnetic induction power-obtaining supply, so that the system is free from being influenced by the weather and the temperature. By means of the system, the all-weather, stable and reliable uninterrupted power supply is realized under various harsh weathers and in different working environments. Meanwhile, the system is maintenance-free for a long period of time and can overcome the defects of solar power supply mode and the like.

The invention discloses a backup-protection confection method and device of a transmission overhead ground wire for important crossed region safety. The technical scheme of the backup-protection confection device of the transmission overhead ground wire for the important crossed region safety is that a main force bearing fixed cable clamp is arranged at the end of an overhead ground wire, and hinged to a transmission pole tower fixed plate through a U-shaped hanging ring and a connecting bolt, furthermore, a backup protection device is arranged on the overhead ground wire close to a transmission pole tower, and comprises a backup fixed cable clamp and an extension rod, wherein the backup fixed cable clamp is fastened together with the overhead ground wire, in addition, the backup fixed cable clamp is hinged to one end of a connecting plate, the other end of the connecting plate is hinged to one end of the extension rod, and the other end of the extension rod is connected with the transmission pole tower fixed plate through a connector to form dual-protection connection. By adopting the backup-protection confection device of the transmission overhead ground wire for the important crossed region safety disclosed by the invention, faults and the fault-trip times of a transmission line are effectively lowered, the outage time of a power grid is reduced, and the power supply quality of the power grid and the customer satisfaction are improved.

The invention provides an energy obtaining terminal for an alternating current overhead ground wire. The energy obtaining terminal comprises a terminal lower shell, a terminal upper shell, a battery case and a protective sleeve, wherein at least one ring-shaped solenoid coil with an iron core is arranged in the terminal lower shell; the terminal upper shell covers the terminal lower shell to form an electricity obtaining terminal shell; the protective sleeve passes through the ring-shaped solenoid coils and stretches out from the two ends of the electricity obtaining terminal shell; the battery case is installed below the terminal lower shell; a charging circuit connected with the two wire outlet ends of the ring-shaped solenoid coils is arranged in the battery case. The energy obtaining terminal for the ground wire can achieve non-damage electricity obtaining from the ground wire, provides an uninterruptable power supply for online monitoring equipment and has a better application market.

The invention relates to a method for the vertical grounding down-leading on the inner side of a composite material pole tower and a pole tower thereof. In the invention, a ground wire cross arm is made of a metal material, a section of grounding down-lead upper metal cross arm with a certain length is led out from the center of the ground wire cross arm along the direction of a wire; a grounding down-lead is led down vertically from the tail end of the upper metal cross arm; the grounding down-lead which is a certain distance below a lower phase wire is connected to the pole tower by a grounding down-lead lower metal cross arm, and the grounding down-lead extends downwards along the body of the tower to be grounded; and if the lower part of the body of the tower is made of steel tubes, the grounding down-lead can be grounded on the steel tubes directly. The additional grounding down-lead upper and lower metal cross arms realize that the grounding down-lead of the head of the tower is at a certain distance to the composite material tower body. The pole tower enhances the capabilities of resisting pollution flashover under power frequency of lines, increases the thunder-and-lightning-resistance insulation strength of the lines, avoids the burning of a composite insulator by a power-frequency flow current after lightning flash over is avoided, has a simple structure and is easy to implement.

The invention relates to the technical field of distribution lines, and specifically relates to an intelligent anti-thunder distribution line overhead line structure. The intelligent anti-thunder distribution line overhead line structure comprises a tower, an overhead ground wire, a ground wire support, an insulated tower top and a tower ground wire, wherein the overhead ground wire is an opticalfiber cable, a metal stranded wire is arranged on the outer layer of the optical fiber cable, and an optical fiber is arranged on the inner layer of the optical fiber cable. The optical fiber cable isspanned on the distribution line overhead line structure, the metal stranded wire on the outer layer of the optical fiber cable has the effects of shielding lightning strokes and coupling and reducing lightning current, the optical fiber has a communication function, and simultaneously, intelligent sensing for distribution lines is realized by using a photoelectric effect of the optical fiber andmonitoring wire load current, fault current, tower vibration and the like in a non-contact mode. By setting the insulated tower top and the overhead ground wire, the insulation level of the overheadline structure is greatly promoted through the insulated tower top, and the overhead ground wire has the effect of shielding lightning strokes, so that the lightning withstand level of the distribution line overhead line structure is greatly promoted. By using the intelligent anti-thunder distribution line overhead line structure, the damage on the distribution lines caused by lightning strokes can be reduced, moreover, the power supply reliability of the distribution lines is improved, and high-quality electric power service is provided.

A lightning protection or internal surge device designed to suppress surges on electrical transmission or distribution lines by expending some of the excess energy in the form of corona discharge in both wet and dry conditions. The device is a very thin (of diameter not exceeding 0.1 mm) conducting wire, fiber, filament, or a bundle of such filaments, or a yarn or woven or knitted fabric made of such fibers or wires which is wound around a live conductor or ground wire forming a coil. When the coil is exposed to the fields created by the voltage surges on the line or ground wire it enhances corona losses on the line thereby damping / suppressing the surges as well as prolonging the front time of the surge to reduce its steepness.

The invention discloses a method for preventing reverse power supply of a power grid. The method comprises the steps that a reverse power supply prevention device is preset in the air; a ground connection portion is arranged in an insulation overhead line; the periphery of the ground connection portion is wrapped by a metal foil; adhesive tape is wound at the two ends of the metal foil and extends outwards, and the adhesive tape covers the metal foil ends and a cable sheath at the same time; a protection outer shell is arranged and completely covers the metal foil and the adhesive tape. The invention further discloses a system for preventing reverse power supply of the power grid, the system comprises the reverse power supply prevention device which comprises the open-close type protection outer shell, the adhesive tape and the metal foil, the metal foil wraps the periphery of the ground connection portion in use, the adhesive tape is wound at the two ends of the metal foil and covers the cable sheath outside the metal foil ends and the outer end of the ground connection portion in use, and the protection outer shell is arranged on the periphery of the ground connection portion in use, and completely covers the wrapped metal foil and the wound adhesive tape. The system is simple in structure, convenient to use, effective for a long term, good in safety and high in maintenance efficiency.

A method for vertically grounding and leading down form a center of a composite pole tower includes the following steps: extending a ground down-leading wire from a center of a ground wire cross arm which is made of metal and is positioned on top of the pole tower, wherein the ground down-leading wire is vertically leaded down to the earth form the center of the composite pole tower, wherein when an lower portion of the tower body is a metal pipe, the ground down-leading wire is extended from the center of the composite material and is directly connected to the metal pipe. The method utilizes the advantage of the insulating intensity of the wall of the composite pole tower and enhances the insulating intensity of the transmission line on impact of lightning. The ground down-leading wires are prevented from short-circuiting with the tower body of the composite pole tower, so that advantage of the insulating property of the composite material of the pole towers is realized. Since the ground down-leading wire is penetrated through center of the pole tower, so that the ground down-leading wires are not exposed and are prevented from destroying by external force. And also the method is easy and simple for application.

The invention relates to a method for vertical grounding down leading on the inner side of a composite material tower and the tower. In the invention, a ground wire cross arm is made of a metal material; a section of grounding down-lead upper metal cross arm with a certain length is led out from the center of the ground wire cross arm along the direction of the wire; a grounding down-lead is vertically led down at the tail end of the upper metal cross arm; the grounding down-lead is connected to the tower by a grounding down-lead lower metal cross arm from a place which is a certain distance below a down-phase wire; then the grounding down-lead is led down along the tower body to be grounded; and if the lower part of the tower body is a steel tube, the grounding down-lead can be grounded by being connected directly to the steel tube. The added grounding down-lead upper and lower metal cross arms can keep the grounding down-lead on the tower head and the composite material tower body at a certain distance. The method increases the power frequency pollution flashover resistance and lightning surge and insulation strength of the line and prevents a power-flow current generated after lightning flashover from burning composite rafters. The tower has a simple structure and is easy to implement.

The invention discloses a lightning protection power grid electric power electric wire support tool. The lightning protection power grid electric power electric wire support tool comprises a telescopic sleeve rod, fastening films, screwing rotary knobs, inclined support rods, ground-inserted ground anchors and down conductors; the fastening films are glued above the telescopic sleeve rod; the included support rods are mounted below the screwing rotary knobs; and the down conductors are mounted on the inner sides of the ground-inserted ground anchors. The lightning protection power grid electric power electric wire support tool is scientific and reasonable in structure, and safe and convenient to use; by virtue of setting of the telescopic sleeve rod, the supporting height of the support tool can be adjusted conveniently; by virtue of setting of the fastening films, sliding of the electric wire when the electric wire is connected with the support tool can be prevented; by virtue of setting of the screwing rotary knobs, mounting of the electric wire and the support tool can be more tight and fixed; by virtue of setting of the inclined support rods, higher supporting strength is achieved at the bottom of the support tool, and falling off of the support tool due to strong wind can be prevented; by virtue of the setting of the ground-inserted ground anchors, connection between the support tool and the ground can be more stable; and by virtue of setting of the down conductors, thunder and lightning voltage can be introduced to the ground conveniently, so that lightning stroke onthe electric wire can be prevented.

The invention relates to a 10 KV dropping fuse cable electricity testing ground wire. The ground wire includes a combination load that is installed on a cement pole; one side of the combination load is connected with a dropping fuse tool and the other side of the combination load is connected with a support porcelain insulator; and the lower end of the support porcelain insulator is connected with an electricity testing ground wire that is connected with a high voltage cable head. The electricity testing ground wire is characterized in that: the ground wire comprises a square annulus that is manufactured by conductor materials; the square annulus is connected with a connecting wire; silicone rubber insulation sleeves are arranged outside the square annulus and the connecting wire; one end of the connecting wire is connected with a lower wiring point of the dropping fuse tool; and one end of the square annulus is an electricity testing grounding point that is suspended with the ground wire. Besides, a high-voltage cable wiring point is made at the bottom of the square annulus; and the high-voltage cable wiring point and the high-voltage cable head are connected.

The invention relates to a grounding wire of an overhead power transmission line, which comprises a grounding chuck (6), insulating ropes (4), a soft copper wire (5) and a spring hook head (1), wherein one end of the soft copper wire (5) is connected onto the spring hook head (1), and the other end of the soft copper wire (5) is connected onto the grounding chuck (6); the grounding chuck (6) is fixed on a tower or a grounding pole embedded into ground; the spring hook head (1) is chucked and held on a guide line; a hook head turnover mechanism (3) is arranged below the spring hook head (1); and the two insulating ropes (4) are respectively connected onto a handle part at the upper part of the spring hook head (1) and the hook head turnover mechanism (3). The grounding wire of the overhead power transmission line, provided by the invention, effectively solves the problem of difficulty in hooking the grounding wire of the overhead power transmission line with 220 to 500kV, and existing three degrees of freedom of a guide line terminal controlled by an operator is improved to be more than five degree of freedoms.

The present invention discloses a temporary ground wire, and belongs to the technical field of electric power equipment safety. The temporary ground wire comprises a temporary ground wire body, a hook end, and a ground end, wherein the hook end of the temporary ground wire is provided with an identity mark that can be read and characterizes the identity of the temporary ground wire; and the temporary ground wire further comprises a ring-buckled ground wire lock, wherein the ring-buckled ground wire lock can make the temporary ground wire body in a folded state that the length cannot satisfy the hooking requirement, or make the temporary ground wire in a freely stretched state. By using the temporary ground wire disclosed by the present invention, leakage of disconnection of ground wire can be effectively prevented, and accidental operations of "closing without disconnecting the ground wire" can be reduced.

A shield grounding device includes: a grounding angle steel (1); a flat iron (9) mounted on a top portion of the shield grounding device; and a laminated board (5) connected to overground wires; wherein two shield connection boards (2) vertical to each other are respectively connected to two external surfaces of an top end of the grounding angle steel, the shield connection boards are vertically mounted on each other by a locating supporter (3), fixing holes (4) are drilled on the shield connection boards for connecting the flat iron and the laminated board. The device solves problems of conventional grounding devices that a grounding resistance is increased and a grounding effect is poor caused by unstable welding quality of grounding electrodes and the flat iron. Besides, site operation difficulty is sufficiently lowered, labor intensity is decreased, and labor efficiency is increased, in such a manner that a cost is lowered.

An overhead ground wire energy retrieval system includes a control terminal and a plurality of overhead ground wire energy taking devices, the overhead ground wire energy extracting device is installed on the pole tower at the consecutive section of the optical fiber composite ground wire, Include Extender, Electrical energy converters and residual cable racks, Also included are a plurality of OPGW insulation supports, a splicer for splicing optical fibers in an optical fiber composite ground wire, a remaining cable frame for collecting an overlong optical fiber composite ground wire, the splicer and the remaining cable frame both have an insulation structure and are insulated and installed on a pole tower, an electric energy converter is installed on the splicer, and the electric energy converter is serially connected with a steel strand of the optical fiber composite ground wire; The OPGW insulation support is installed on the top of the tower, and is used for leading the optical fiber composite ground wire down the tower insulation along the top of the tower and connecting the extender or the remaining cable rack. The invention replaces the original OPGW optical fiber connectiondevice to extract electric energy and finish the optical fiber connection, can obtain electric energy from the ground wire to supply power for the on-line monitoring device, reduces the loss of OPGW,and also can control the grounding mode of OPGW at the segmentation.

Induction thunder shield wire for lightning protection is laid near to overhead insulated conductor. Distance between shield wire and insulated conductor is 0.20m ¿C 1m. The shield wire is installed and connected to cross arm of wire pole of overhead line. Two ends of shield wire, and every 2-5 pieces of wire pole in middle are grounded enforcedly. Ground resistance is less than 30 ohm. Advantages are: advance method, low cost, small quantity of maintenance work. The shield wire shows good effect for lowering thunder inducted voltage on the overhead insulated conductor. The method is suitable to 10KV overhead insulated conductor for lightning protection.

The invention discloses a method for preventing reverse power supply of a power grid. The method comprises the steps that a reverse power supply prevention device is preset in the air; a ground connection portion is arranged in an insulation overhead line; the periphery of the ground connection portion is wrapped by a metal foil; adhesive tape is wound at the two ends of the metal foil and extends outwards, and the adhesive tape covers the metal foil ends and a cable sheath at the same time; a protection outer shell is arranged and completely covers the metal foil and the adhesive tape. The invention further discloses a system for preventing reverse power supply of the power grid, the system comprises the reverse power supply prevention device which comprises the open-close type protection outer shell, the adhesive tape and the metal foil, the metal foil wraps the periphery of the ground connection portion in use, the adhesive tape is wound at the two ends of the metal foil and covers the cable sheath outside the metal foil ends and the outer end of the ground connection portion in use, and the protection outer shell is arranged on the periphery of the ground connection portion in use, and completely covers the wrapped metal foil and the wound adhesive tape. The system is simple in structure, convenient to use, effective for a long term, good in safety and high in maintenance efficiency.

The invention relates to a method for vertical grounding led-down outside a composite material pole tower and a pole tower thereof. In the method, a section of grounding lead upper metal cross arm is erected on an extension line on one side of a grounding cross arm; a grounding lead is led down vertically at the tail end of the metal cross arm; the grounding lead is connected to the pole tower through a corresponding grounding lead lower metal cross arm at a distance below a bottom phase lead, and finally, the grounding lead is grounded along a tower body; and if the lower part of the tower body is a steel pipe, the grounding lead can be connected to the steel pipe directly for grounding through the grounding lead lower metal cross arm. The method is favorable for compressing the width of a power transmission passageway to the utmost extent, and simultaneously is favorable for the design of lightning protection, prevents the grounding lead from being short-circuited with the tower body of the composite material pole tower, and gives play to the insulation function of the composite material tower body; besides, a unilateral grounding lead is adopted, so the method saves more materials is more economical, the structure is simple and convenient, and the method is easy to implement.