JP4615258B2 - Power cable termination connection and assembly method - Google Patents

Description

  The present invention relates to a terminal connection of a power cable such as a gas terminal connection part, an oil terminal connection part or an air terminal connection part used in a connection part between a power device and a power cable arranged in a power plant, a substation, etc. Part and its assembly method.

  In general, a power cable such as a CV (crosslinked polyethylene insulation) cable is provided with a shielding layer (external semiconductive layer) on the insulator in order to reduce electric field stress in the insulator. When forming the terminal connection portion of such a power cable, simply removing the shielding layer may concentrate electric field stress on the end portion of the shielding layer and cause dielectric breakdown.

  When such a power cable is connected to an end-of-gas connection box or an end-of-oil connection box used in power equipment such as GIS (Gas Insulated Swichgear), electric field stress should not be concentrated. In addition, for example, it is known to use a power cable terminal connection portion including an in-gas terminal connection box shown in Patent Document 1.

FIG. 10 is a diagram illustrating an example of a conventional cable termination connection section. The in-gas termination junction box 1 shown in FIG. 10 is a slip-on type in-gas termination junction box for CV cables. This in-gas termination junction box 1 is attached to the outer wall 2 of a gas insulated power device such as GIS. An insulating gas such as SF ₆ (sulfur hexafluoride) gas is filled around the end-of-gas junction box 1 inside the outer wall 2.

  In the end-of-gas junction box 1, a sleeve 3 made of an insulator such as an epoxy resin is airtightly attached to the inside of the outer wall 2 of the device. A power cable 4 inserted from below is connected to the receiving port of the sleeve 3. The power cable 4 is subjected to terminal treatment at the terminal, the insulator is stripped off, and the conductor 5 is exposed. The power cable 4 is in a state where the outer shielding layer is grounded in the in-gas termination junction box 1.

  A high voltage electrode 8 a is provided in the upper portion of the sleeve 3, and a conductor 5 that is a terminal of the power cable 4 is electrically connected through a sleeve 6 and a contact 7.

  A conductor lead bar 8 is integrally formed at the upper end of the high-voltage electrode 8a, is exposed from the upper portion of the cannula 3, and is electrically connected to a gas insulated power device such as a circuit breaker (not shown).

  Further, a stress cone 10 is inserted between the insulator 9 of the power cable 4 and the receiving port of the sleeve 3. The stress cone 10 includes an insulating rubber portion 10a made of ethylene propylene rubber and a conductive rubber portion 10b. The stress cone 10 is pressed into the receiving opening of the cannula 3 by a pressing mechanism 14 including a push pipe 11, a spring 12, and a flange 13. .

  As a result, in the in-gas termination junction box 1, the conductor 5 of the power cable 4 is connected inside the outer wall 2, that is, in the cannula 3, and the surface of the stress cone 10 and the inner surface of the cannula 3 are brought into close contact with each other. Thus, sufficient insulation characteristics of these interfaces 15 can be obtained. FIG. 11 is a diagram showing a distribution of equipotential surfaces at the time of voltage application in FIG.

As shown in FIG. 11, the end-of-gas junction box 1 is insulated by composite insulation in which an insulator 9 made of cross-linked polyethylene, an insulating rubber portion 10a made of ethylene propylene rubber, and a sleeve 3 made of epoxy resin are brought into close contact with each other. And relieve electric field stress. Note that a lower end portion of the high voltage electrode 8a is arranged on the upper portion of the stress cone 10 so as to cover the vicinity of the upper end, and the upper end of the stress cone is electrically shielded.
JP 2002-135959 A

  However, as shown in Patent Document 1, the cable end connection portion using the stress cone 10 employs a composite insulating structure made of different materials such as cross-linked polyethylene, ethylene propylene, and epoxy resin. (Ref.), It cannot be denied that the equipotential surface is disturbed. Therefore, there is a desire to suppress the disturbance and improve the electric field relaxation effect (insulation characteristics) at the terminal connection portion.

  Conventionally, in order to maintain the composite insulating structure, the pressing mechanism 14 for bringing the stress cone 10 into close contact with the sleeve 3 is essential.

  Since this pressing mechanism 14 is composed of a plurality of parts such as the push pipe 11, the spring 12, and the flange 13, the cable terminal connecting portion provided with the pressing mechanism 14 takes man-hours for assembly and the terminal connecting portion itself. The size has increased, and the weight has increased accordingly.

  Therefore, it is desired to simplify the structure of the terminal connection part itself, reduce the number of parts, reduce the number of steps, and further reduce the size and weight of the terminal connection part itself.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and it is possible to improve the insulation characteristics (electric field relaxation effect), reduce the number of parts, and easily manufacture the end connection portion and assembly of the power cable. It aims to provide a method.

The terminal connection part of the power cable of the present invention is formed integrally with the cable conductor exposed at the end of the power cable, the embedded conductor connecting the cable conductor, and the embedded conductor, A sleeve portion that insulates the periphery, a conductor connection portion that joins the cable conductor at one end of the embedded conductor, and a cylindrical insulating reinforcement block that covers the conductor connection portion and relaxes the electric field at the conductor connection portion The sleeve portion is disposed in the termination junction box, and has an insulating main body portion having a head for relaxing an electric field on the other end side of the embedded conductor, and outside the termination junction box. wherein and a block insertion portion to be inserted into the insulation reinforcing block, the conductor connecting portion, the block insertion unit is disposed in the inserted said insulating reinforcement block, said insulating reinforcement blocks, An internal electrode that covers the joint portion of the conductor connecting portion and the cable conductor, and an opening that is disposed at a predetermined distance from each end of the internal electrode and that faces each other is an inner circumference of the opening. A trumpet-shaped conductive stress cone portion and bell mouth portion having a gentle slope on the surface, covering the internal electrode and the stress cone portion, and arranged adjacent to the bell mouth portion in the axial direction And a cylindrical covering portion that covers the reinforcing insulating portion and forms an external semiconductive layer together with the bell mouth portion, and the bell mouth portion is externally fitted to the block insertion portion. is the stress cone portion with the said are closely fixed to the outer periphery of the outer semiconductive layer end of the power cable, in terminal connection box, from the outer circumferential surface of the insulating body portion except for the head, said blocks A configuration with a shield layer of conductive paint until fitted on said portion bellmouth abuts is formed by coating on the outer peripheral surface at the outer peripheral surface of the insertion portion.

According to this configuration, the terminal connection portion having the electric field relaxation effect can be obtained by simply attaching the cable conductor exposed at the end portion of the power cable to one end of the conductor portion of the insulated conductor portion (embedded conductor, sleeve portion) . Also, since the electric field at the end of the power cable is alleviated with only the insulation coating that covers the conductor joined to the cable conductor, unlike the conventional case, composite insulation with multiple different materials such as stress cones, sleeves, and insulators Need not be used. As a result, the potential line in the insulating coating portion draws a smooth curve, the electric field relaxation effect (insulation characteristics) in the terminal connection portion can be improved, and the number of parts constituting the terminal connection portion is reduced. The terminal connection itself can be easily manufactured.

  According to this structure, since the junction part of a cable conductor and the end of a conductor part is covered with an insulation reinforcement block, the electric field of the electric field concentration location in a junction part can be relieve | moderated.

  According to this configuration, since the block insertion portion is inserted into the insulation reinforcement block and the joint portion between the cable conductor and the conductor portion is disposed in the insulation reinforcement block, only the insertion portion is inserted into the reinforcement insulation block. Thus, the reinforcing insulating block can cover the joint portion to improve the electric field relaxation effect at the joint portion, and can be easily assembled to improve the workability.

  The terminal connection portion of the power cable according to the present invention may have a configuration in which, in the above configuration, the insulating coating portion is formed of a curable resin such as a polymer material, an epoxy resin, or an acrylic resin.

  According to this configuration, the insulating coating can be easily formed using a curable resin such as a polymer material, an epoxy resin, and an acrylic resin. In particular, when molding is performed by casting, the insulating coating portion in which the conductor portion is embedded can be easily molded, and the insulated conductor portion can be easily manufactured.

  Further, the terminal connection portion of the power cable of the present invention may be inserted into a container filled with an insulating gas or oil inside the sealed electric field relaxation portion of the insulated conductor portion, or in the atmosphere. And the joint portion includes an exposed termination connection box, and the termination connection box has a joint portion between the conductor connection portion and the power cable conductor, and the reinforcing insulating block is provided in the joint portion. You may take the structure to cover.

  According to this configuration, the insulating property (electric field relaxation effect) can be improved, and the end-in-gas connection or the end-in-oil connection can be easily produced with a small number of parts.

The method for assembling the end connection portion of the power cable according to the present invention is a method for assembling the end connection portion of the power cable having the above-described configuration, wherein the insulation reinforcing block is formed by a rubber elastic body extending in the diameter increasing direction. The insulation reinforcing block whose diameter is increased in advance is disposed around the conductor connection portion where the embedded conductor and the power cable conductor are joined, and then the power cable conductor is joined to one end of the embedded conductor. The block insertion portion is disposed in the insulation reinforcing block , the bell mouth portion is fitted on the outer peripheral surface of the block insertion portion, the internal electrode is covered on the conductor connection portion, and then the insulation The reinforcing block was reduced in diameter so as to be in close contact with the outer periphery of the conductor connecting portion and covered.

  According to this method, after the cable conductor is joined to one end of the conductor portion of the insulated conductor portion, the diameter of the insulation reinforcement block expanded in advance is arranged around the joint portion of the conductor portion, the cable conductor, and the conductor portion to reduce the diameter. By doing so, it adheres to the outer periphery of a junction part, and covers a junction part. For this reason, unlike the conventional case, the terminal connection portion can be assembled without using a composite insulation and a pressing mechanism necessary for the composite insulation. Therefore, when assembling the terminal connection portion, the number of parts is small and the number of man-hours is small, so that the terminal connection portion can be easily assembled.

  As described above, according to the present invention, the insulation characteristics (electric field relaxation effect) can be improved, the number of parts is small, and the manufacturing can be performed easily.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a partial cross-sectional view showing a configuration of a terminal connection portion of a power cable according to an embodiment of the present invention. Note that FIG. 1 and the partial cross-sectional views of each drawing show a portion other than the power cable portion in cross-section for convenience.

  The terminal connection portion of the power cable according to the present invention is used to connect to a transformer, an overhead line, a bus line of a substation, or the like. Specifically, the present invention may be applied as any type of termination connection portion, such as an air termination connection portion, an oil termination connection portion, and a gas termination connection portion. Here, GIS (Gas Insulated Swichgear) The description will be made by applying to an end-of-gas connecting portion attached to a gas insulated power device such as a device.

  1 is provided in a cable conductor 112 that constitutes an end of the power cable 110, an insulated conductor portion 130 connected to the cable conductor 112, and a gas-insulated power device such as a GIS. And a closed terminal junction box 200.

  The power cable 110 is configured by covering the periphery of the cable conductor 112 in order from the inside with an internal semiconductive layer (not shown), a cable insulator 114, an external semiconductive layer 116, a metal shielding layer 118, and a cable sheath 120. Yes.

  Then, the cable conductor 112, the cable insulator 114, the external semiconductive layer 116, and the metal shielding layer 118 are exposed from the end 110a of the power cable 110 in a predetermined length in order from the end of the power cable 110.

  That is, the end portion 110a of the power cable 110 is formed by stripping the cable insulator 114, the external semiconductive layer 116, the metal shielding layer 118, and the cable sheath 120 constituting the power cable 110 in order from the outside by a predetermined length. It is configured.

  Here, the cable insulator 114 is made of an insulating rubber plastic material, for example, ethylene propylene rubber, polyethylene, cross-linked polyethylene, or the like. The outer semiconductive layer 116 is made of a conductive material, such as an ethylene propylene rubber, an elastomer such as polyethylene or silicone rubber, ethylene vinyl acetate, or carbon such as an ethylene vinyl acetate. It is made of a mixture of conductive materials such as

  At the end 110 a of the power cable 110, one end 132 a of a buried conductor 132 disposed on the same line as the power cable 110 is fixed to the cable conductor 112 exposed at the end of the power cable 110. Hereinafter, the one end portion 132a of the embedded conductor 132 is referred to as a conductor connecting portion 132a.

  The embedded conductor 132 is made of a long member, and an insulating portion (hereinafter referred to as “cannon portion”) 134 is integrally provided around the main body portion 132b extending from the conductor connection portion 132a. Specifically, the embedded conductor 132 is formed by being embedded in the sleeve portion 134, and is disposed so that the conductor connection portion 132 a is exposed to the outside of the termination connection box 200 and the other end portion 132 c is positioned in the termination connection box 200. Has been.

  The conductor connecting portion 132a is fixed by a bolt 1322 that protrudes into the recess from the side wall of the recess by inserting the cable conductor 112 into the recess that opens to the end face side. The tip of the bolt 1322 is bitten into the peripheral wall portion of the cable conductor 112 to prevent the cable conductor 112 itself from coming off. In addition, the other end part 132c is matched with the electric equipment connected.

  The sleeve portion 134 is formed, for example, by casting an epoxy resin so as to cover the main body portion 132 b of the embedded conductor 132.

  The sleeve portion 134 has a cylindrical shape in which the embedded conductor 132 is inserted, and is attached to the outer wall 210 via attachment members such as an insert fitting 1344 and a bolt 1345.

  The sleeve portion 134 includes an insulating main body portion 1341 disposed in the terminal junction box 200 and a block insertion portion 1342 that is integrally formed with the insulating main body portion 1341 and is disposed outward with respect to the outer wall 210.

  The insulating main body portion 1341 has a cylindrical shape and has a flange portion 1343 projecting outward from the central portion of the outer peripheral surface thereof. A cylindrical insert fitting 1344 is attached to the flange portion 1343, and an O-ring 1347 is sandwiched between the edge portion (opening edge portion) 214 of the opening 212 of the outer wall 210 by a bolt 1345 inserted through the insert fitting 1344. And attached from the back side of the outer wall 210. The O-ring 1347 maintains the airtightness in the terminal junction box 200.

  The insulating main body part 1341 has a head part 1341b for relaxing the electric field on the other end part 132c side of the embedded conductor 132, and the head part 1341b has a truncated cone shape that narrows toward the other end part 132c side of the embedded conductor 132. Make a cylinder.

  Electric field relaxation is performed on the narrowed outer surface 136 of the head portion 1341b, and a shielding layer 1346 is formed on the outer surface of the insulating main body portion 1341 excluding the head portion 1341b by applying a conductive paint.

  The block insertion portion 1342 is formed with an insertion hole through which the embedded conductor 132 is inserted, and this insertion hole has the same diameter as the insertion hole in the insulating main body portion 1341. The block insertion portion 1342 has a cylindrical shape with an outer diameter smaller than the outer diameter of the insulating main body portion 1341.

  The block insertion portion 1342 is inserted into the insulation reinforcement block 160 which is closely fixed to the periphery together with the cable conductor 112 and the cable insulator 114, and is covered with the insulation reinforcement block 160.

  The shielding layer 1346 is formed from the outer peripheral surface of the insulating main body portion 1341 to a portion that contacts the bell mouth portion 167 having conductivity of the insulating reinforcing block fitted on the outer peripheral surface of the block insertion portion 1342.

  The insulation reinforcement block 160 includes an internal electrode 162, a stress cone part 164, a reinforcement insulation layer 166, a bell mouth part 167, and an external semiconductive layer 168.

  The insulating reinforcing block 160 may have any function as long as it has the internal electrode 162, the stress cone portion 164, the reinforcing insulating layer 166, and the external semiconductive layer 168, for example. May be. For example, the insulating reinforcement block may be formed by winding up an insulating rubber tape into the shape of each part.

  In the insulation reinforcement block 160 of this embodiment, the internal electrode 162, the stress cone portion 164, the reinforcement insulation layer 166, and the external semiconductive layer 168 are made of, for example, silicone rubber, ethylene propylene (Ethylene Propylene Diene Terpolymer: EPDM, Ethylene Propylene). Methylene Linkage (EPM) is integrally formed by a cylindrical body made of a rubber elastic body made of a material such as rubber. The insulation reinforcing block 160 is in a contracted state when mounted.

  The internal electrode 162 has conductivity, and both end portions 162a and 162b are provided with a structure that prevents concentration of the electric field, such as being rounded, respectively. The conductor connecting portion 132a and the cable conductor 112 side of the cable insulator 114 are employed. The edge is covered.

  The internal electrode 162 is placed on the joint portion between the cable conductor 112, which is the exposed end portion of the power cable, and the conductor connection portion 132a of the embedded conductor 132, and the electric field is most concentrated in this joint portion, and the electric field on the high voltage side. The electric field in the vicinity of the surface and corners of the conductor connection portion 132a that becomes the concentrated portion is relaxed.

  The internal electrode 162 is formed of a rubber plastic material having conductivity, such as ethylene propylene rubber, silicone rubber, or ethylene vinyl acetate mixed with a conductive material such as carbon.

  The stress cone portion 164 and the bell mouth portion 167 have conductivity, and have openings 164b and 167b that open in a trumpet shape from the base end portions 164a and 167a toward the distal end side, respectively. The bell mouth portion 167 is integrally formed as an outer semiconductive layer 168 together with the cylindrical covering portion 169.

  The stress cone portion 164 and the bell mouth portion 167 are arranged at positions spaced from the both end portions 162a and 162b of the internal electrode 162 by a predetermined distance so that the openings 164b and 167b face each other.

  That is, in the stress cone portion 164 and the bell mouth portion 167, the rising portions 164c and 167c are not formed as sharp protrusions on the inner peripheral surfaces of the opposing openings 164b and 167b (inner surfaces of the openings 167b and 164b). The shape has a gentle slope (curved surface here).

  With this configuration, the stress cone portion 164 and the bell mouth portion 167 relieve the electric field at the electric field concentration portion (near the rising portions of the stress cone portion 164 and the bell mouth portion 167) on the low voltage side.

  The stress cone portion 164 is tightly fixed to the outer periphery of the end portion of the outer semiconductive layer 116 of the power cable.

  The stress cone portion 164 is formed by mixing a conductive material such as carbon with a rubber plastic conductive material such as ethylene propylene rubber, silicone rubber, or ethylene vinyl acetate together with the outer semiconductive layer 168. Has been.

  The reinforcing insulating layer 166 is insulative, is axially adjacent to the bell mouth portion 167 of the outer semiconductive layer 168, and is located inside the cylindrical covering portion 169 of the outer semiconductive layer 168, 162 and the stress cone part 164 are covered and provided integrally.

  The cylindrical covering portion 169 is provided above the internal electrode 162, covers the reinforcing insulating layer 166, and has one end connected to the upper end of the opening 167b of the bell mouth portion 167. Further, on the other end portion side of the cylindrical covering portion 169, an edge cut portion 166a that is spaced apart above the stress cone portion 164 and insulated from the stress cone portion 164 is formed.

  The reinforcing insulating layer 166 is made of a predetermined material having an insulating property, preferably a rubber plastic material having an insulating property, for example, an elastomer such as ethylene propylene rubber or silicone rubber.

  In the terminal connection portion 100 thus provided, the insulating cylinder 142 surrounding the joint portion including the block insertion portion 1342 protruding from the outer wall 210 is provided via the adapter 140 fixed to the outer surface of the outer wall 210 with the bolt 141. It is attached. Further, a protective metal fitting 144 is put on the end portion of the insulating tube 142 on the power cable side to fix the end portion 110a of the power cable 110 and cover the joint portion of the end portion 110a of the power cable 110.

  FIG. 2 is a diagram showing a distribution of equipotential surfaces at the time of voltage application in the terminal connection portion shown in FIG.

  The embedded conductor 132 to be joined to the cable conductor 112 is covered with a sleeve portion 134 formed of one kind of material, here, epoxy resin. For this reason, the equipotential lines are smooth at substantially equal intervals, as is clear from the distribution of the equipotential surface indicated by the symbol B in FIG. 2, and the termination connecting portion 100 has stable insulation performance.

  Next, a method of assembling the power cable termination connection 100 will be described.

  3 to 6 are partial cross-sectional views for explaining an assembly process of the terminal connection portion of the power cable according to the present invention.

  First, as shown in FIG. 3, an insulating main body part 1341 is disposed in a termination junction box 200 attached to a gas-insulated power device such as a GIS, and a block insertion part 1342 is disposed outward from the opening 212 of the outer wall 210. The insulated conductor 130 is attached in a protruding manner. Specifically, the insulated conductor portion 130 is disposed such that the conductor connecting portion 132 a and the other end portion 132 c of the embedded conductor 132 are positioned on a straight line that is substantially orthogonal to the outer wall 210.

  Next, the bolt 1345 is inserted through the insert fitting 1344 of the flange portion 1343, and the cannula portion 134 is fixed to the outer wall 210 from the back surface side of the outer wall 210 with the opening portion 212 closed by the flange portion 1343.

  On the other hand, when the power cable 110 to be connected (see FIG. 1) is a rubber plastic insulated power cable, the connecting end 110a (see FIG. 1) is brought into a connectable state. Specifically, at the end 110a of the power cable 110, the cable sheath 120 is peeled off from the end surface of the power cable 110 to a predetermined position, and a metal shielding layer (so-called wire shield) 118 is folded back to the cable body side. As a result, the external semiconductive layer 116 is exposed (see FIG. 1).

  Next, the cable insulator 114 at the power cable end portion 110a is peeled off to the length necessary for conductor connection, exposing the cable conductor 112, and processing the outer semiconductive layer 116 to a predetermined length. Here, the predetermined length is longer than the length C (see FIG. 1) of the insulator exposed inside the insulating reinforcing block to be attached, and the external semiconductive layer 116 is trimmed so as to be this length.

  Next, the reinforcing insulating block 160 is set on the power cable 110 (see FIG. 1). As this setting method, there is a method in which an existing inner core is inserted into the reinforcing insulating block 160 in advance and the diameter thereof is expanded to increase the diameter, and the expanded insulating insulating block 160 is passed through the power cable.

  The inner core is formed by using a synthetic resin or the like and forming a molded body processed into a band shape or a string shape having a strength that is not crushed by the reinforcing insulating block 160 into a spiral cylindrical body. By covering the reinforced insulating block 160 whose diameter is increased, the reinforced insulating block 160 can maintain a predetermined diameter.

  Thus, the reinforcing insulating block 160 supported by the inner core 182 (see FIG. 5) is a place where the reinforcing insulating block 160 is attached. By pulling out the inner core, the reinforcing insulator block 160 can be shrunk to cover the object.

  Further, without expanding the diameter, the outer semiconductive layer 116 of the power cable 110 is exposed to a length that is structurally necessary, that is, longer than that required when the reinforcing insulating block 160 is disposed at a predetermined position. A method of making the insulation reinforcing block 160 slidable on the outer semiconductive layer 116 of the power cable 110 can be mentioned.

  Before inserting the reinforcing insulating block 160 into the power cable, the protective metal fitting 144, the insulating cylinder 142, and the adapter 140 are inserted as necessary.

  Next, the insulation reinforcing block 160 is set (not shown), and as shown in FIG. 4, the cable conductor 112 at the end of the power cable 110 whose end is processed is inserted into the recess of the conductor connecting portion 132a. The bolt 1322 is tightened to join the conductor connection portion 132a.

  Next, the insulation reinforcing block 160 is positioned on the conductor connecting portion 132a and fixed in a close contact state.

  FIG. 5 is a diagram showing a case where a reinforcing insulating block whose diameter is expanded in advance is used.

  As shown in FIG. 5, when the insulation reinforcement block 160 whose diameter has been expanded in advance is passed through the power cable 110, it is disposed on the conductor connection portion 132a.

  Then, the inner core 182 is disassembled to release the expanded diameter state of the insulation reinforcing block 160 and fixed in a state of being in close contact with the periphery of the conductor connecting portion 132a (see FIG. 6).

  On the other hand, if the insulation reinforcing block 160 is inserted into the power cable 110 without being expanded in diameter, the insulation reinforcing block 160 is shifted to the top of the conductor connecting portion 132a and is in close contact with the conductor connecting portion 132a.

  The stress cone portion 164 and the external semiconductive layer 116 of the power cable 110 are connected to each other at both ends of the insulation reinforcing block 160 fixed around the conductor joint portion using, for example, a conductive rubber tape. Further, a metal shielding layer is provided on the surface of the bell mouth portion 167 and the external semiconductive layer 168.

  Next, the reinforcing insulating block 160 is covered with the adapter 140 and the insulating cylinder 142 and the protective metal fitting 144 that block the current flowing to the shielding layer side, and the insulating cylinder 142 and the end 110a of the power cable 110 are connected and protected. (See FIG. 1). And it connects with the adapter 140 and performs an electrical connection process.

Then, the terminal connection box 200 is filled with an insulating gas, here, SF ₆ (sulphur hexafluoride) gas.

  According to the present embodiment, the terminal connection portion 100 having the electric field relaxation effect can be obtained simply by attaching the cable conductor 112 exposed at the end portion 110 a of the power cable 110 to the conductor connection portion 132 a of the embedded conductor 132.

  Further, since the electric field at the end of the power cable 110 is alleviated only by the cannula part 134 covering the embedded conductor 132 joined to the cable conductor 112, a plurality of different ones such as a stress cone, a cannula, and an insulator are different from conventional ones. There is no need to use composite insulation by material.

  Thereby, the potential line in the cannula part 134 draws a smooth curve, the electric field relaxation effect (insulation characteristics) in the terminal connection part can be improved, and the number of parts constituting the terminal connection part is small. Therefore, production can be performed easily.

  Moreover, since the junction part of the cable conductor 112 and the conductor connection part 132a of the embedded conductor 132 is covered with the insulation reinforcement block 160, the electric field of the electric field concentration part in a junction part can be relieve | moderated.

  Further, at the joint portion between the cable conductor 112 and the buried conductor 132, the joint portion between the cable conductor 112 and the conductor connection portion 132 a of the buried conductor 132 is covered with the internal electrode 162, and the internal electrode 162 is covered with the reinforcing insulating layer 166. The reinforcing insulating layer 166 is covered with an external semiconductive layer 168.

  For this reason, only by attaching the reinforcement insulation block 160 to a junction part, the electric field relaxation effect in a junction part can be aimed at, workability can be improved, and it can assemble easily.

  Further, the cannula part 134 can be easily formed using a polymer material, an epoxy resin, and an acrylic resin. In particular, when forming by casting, the cannula part 134 in which the conductor part is embedded can be easily formed, and the insulated conductor part 130 can be easily manufactured.

  Further, since the block insertion portion 1342 is inserted into the insulation reinforcement block 160 and the joint portion of the cable conductor 112 and the embedded conductor 132 is disposed in the insulation reinforcement block 160, the block insertion portion 1342 is inserted into the reinforcement insulation block 160. As a result, the reinforcing insulating block 160 covers the joint portion and can improve the electric field relaxation effect at the joint portion, and can be easily assembled, thereby improving workability.

  In addition, in the termination | terminus connection part 100 of this Embodiment, although the insulated conductor part 130 was formed in the linear shape and it was set as the structure attached to GIS etc., not only this but as a shape corresponding to the location where a termination | terminus connection part is attached Also good.

  For example, as an attachment to a side surface such as C-GIS, the insulated conductor 130 may be formed in an L shape and attached. This example is shown as Modification 1.

(Modification 1)
Termination connection section 300 of Modification 1 has the same basic configuration as termination connection section 100 corresponding to Embodiment 1 shown in FIG. 1, and the same components are denoted by the same reference numerals. The description is omitted.

  FIG. 7 is a partial cross-sectional view showing a first modification of the terminal connection portion of the power cable according to the present invention.

  7 includes an insulated conductor 330 in which the insulated conductor 130 of the termination connector 100 is L-shaped. Since the action of the insulated conductor 330 is substantially the same as that of the insulated conductor 130, description thereof is omitted. In other words, the insulated conductor portion 330 has a buried conductor 332 that is longer than the buried conductor 132 and is formed in an L shape, and an insulating portion 334 that covers the buried conductor 332. The power cable is connected to the conductor connection portion 332a that is one end portion of the embedded conductor 332. The other end of the embedded conductor 332 is disposed in the termination connection box 230. Since the other end portion of the embedded conductor 332 has the same configuration as the embedded conductor 132a of the termination connection portion 100, the same reference numerals are given and description thereof is omitted.

Thus, in the terminal connection box 230 which SF ₆ gas is filled, if it is desired to form a sealing end 300 to the side surface portion 232, it can be easily formed.

  Further, in the present embodiment, the end connection unit 100 has been described as an in-gas end connection unit. However, the present invention is not limited thereto, and may be used as an in-air end connection unit or an in-oil end connection unit.

  When used as an air termination connection part or an oil termination connection part, the shape of the insulated conductor 130 may be changed.

(Modification 2)
FIG. 8 is a partial cross-sectional view showing a second modification of the terminal connection portion of the power cable according to the present invention.

  Termination connection section 400 of Modification 2 has the same basic configuration as termination connection section 100 corresponding to Embodiment 1 shown in FIG. 1, and the same components are denoted by the same reference numerals. The description is omitted.

  8 includes a plurality of folds 410 provided on the outer peripheral surface of the head part 1341b of the insulating main body part 1341 in the cannula part 134 in the terminal connection part 100.

  That is, the terminal connection portion 400 includes a sleeve portion 434 provided with an insulating main body portion 4341 having a plurality of fold portions 410 projecting in the radial direction instead of the insulating main body portion 1341 in the configuration of the terminal connection portion 100. . That is, the sleeve portion 434 includes an insulating main body portion 4341 and a block insertion portion 4342 formed integrally with the insulating main body portion 4341.

  In addition, since an attachment method, an effect, etc. are the same as that of the cannula part 434 of the termination | terminus connection part 100, description is abbreviate | omitted. In FIG. 8, the end-in-oil connection portion including the end connection box 250 filled with oil has been described. However, the present invention is not limited thereto, and the outer wall 252 of the end connection box 250 shown in FIG. Of course, it may be used as a connecting portion.

  Moreover, although this Embodiment demonstrated as a termination | terminus connection part of one power cable, it is good not only as this but also as a termination | terminus connection part of a some power cable.

(Modification 3)
FIG. 9 is a partial cross-sectional view showing a third modification of the terminal connection portion of the power cable according to the present invention.

  Termination connection unit 500 of Modification 3 has the same basic configuration as termination connection unit 100 corresponding to Embodiment 1 shown in FIG. 1, and the same components are denoted by the same reference numerals. The description is omitted.

  A termination connection unit 500 shown in FIG. 9 is connected to a plurality of power cables 110 </ b> A and 110 </ b> B in the termination connection unit 500.

  In this terminal connection part 500, the insulated conductor part 530 having basically the same configuration and function as the insulated conductor part 130 forms a plurality of recesses in the conductor connection part 532a of the embedded conductor 532, and each of the recesses has a power supply. Cable conductors 112 and 112 of the cables 110 </ b> A and 110 </ b> B are inserted and joined via bolts 1322.

  Openings 581 and 582 corresponding to the plurality of power cables 110A and 110B to be connected are formed in the insulation reinforcing block 560 that covers these joint portions. In the third modification, the insulation reinforcing block 560 is formed in a T shape. Since the basic configuration of the insulation reinforcing block 560 is the same as that of the insulation reinforcing block 160, the same reference numerals are given and description thereof is omitted.

  In other words, the insulating reinforcement block 560 includes the external electrode 1620 having conductivity, the stress cone portion 164 having conductivity, the reinforcing insulation layer 166 having insulation, and the bell mouth portion 167 having conductivity. A conductive layer 168.

  Here, the internal electrode 1620 is formed with an opening into which the embedded conductor 532 is inserted, an opening into which two power cables are inserted, and three openings. According to this termination connection unit 500, a plurality of power cables can be connected at one place.

  The terminal connection part according to the present invention is useful as an element that can improve insulation characteristics (electric field relaxation effect), has a small number of parts, and can be easily produced.

The fragmentary sectional view which shows the structure of the termination | terminus connection part of the power cable which concerns on one embodiment of this invention The figure which shows equipotential surface distribution at the time of the voltage application in the termination | terminus connection part shown in FIG. Partial sectional view for explaining the assembly process of the terminal connection portion of the power cable Partial sectional view for explaining the assembly process of the terminal connection portion of the power cable Partial sectional view for explaining the assembly process of the terminal connection portion of the power cable Partial sectional view for explaining the assembly process of the terminal connection portion of the power cable The fragmentary sectional view which shows the modification 1 of the termination | terminus connection part of the power cable which concerns on this invention The fragmentary sectional view which shows the modification 2 of the termination | terminus connection part of the power cable which concerns on this invention The fragmentary sectional view which shows the modification 3 of the termination | terminus connection part of the power cable which concerns on this invention The figure which shows an example of the termination | terminus connection part of the conventional power cable The figure which shows distribution of the equipotential surface at the time of the power application in FIG.

Explanation of symbols

100, 300, 400, 500 Termination connector 110, 110A, 110B Power cable 110a Power cable end 112 Cable conductor 114 Cable insulator 116 External semiconductive layer 118 Metal shielding layer 130 Insulated conductor portion 132, 332, 532 Embedded conductor 132a Conductor connection portion 134, 434 Sleeve portion 160, 560 Insulation reinforcement block 162 Internal electrode 164 Stress cone portion 166 Reinforcement insulation layer 167 Bell mouth portion 168 External semiconductive layer 200, 230, 250 Terminal connection box 210, 252 Outer wall 212 Opening Part 214 opening edge part 410 crease part 1342, 4342 block insertion part

Claims (4)

A cable conductor exposed at an end of the power cable; an embedded conductor connecting the cable conductor; a sleeve portion integrally formed with the embedded conductor and insulating the periphery of the body portion of the embedded conductor; and the embedded A conductor connecting portion that joins the cable conductor at one end of the conductor, and a cylindrical insulating reinforcing block that covers the conductor connecting portion and relaxes an electric field in the conductor connecting portion;
The sleeve portion is disposed in a termination junction box and has an insulating main body portion having a head for relaxing an electric field on the other end side of the embedded conductor; and the insulation reinforcing block outside the termination junction box And a block insertion portion to be inserted into
The conductor connection portion is disposed in the insulation reinforcement block in which the block insertion portion is inserted,
The insulation reinforcement block is disposed at an internal electrode that covers a joint portion between the conductor connection portion and the cable conductor, and at a predetermined distance from both ends of the internal electrode, and openings that face each other are A trumpet shape in which the inner peripheral surface of the opening has a gentle slope, and covers the conductive stress cone portion and the bell mouth portion, the internal electrode and the stress cone portion, and the bell mouth portion has a shaft. A reinforcing insulating portion disposed adjacent to the direction, and a cylindrical covering portion that covers the reinforcing insulating portion and forms an external semiconductive layer together with the bell mouth portion;
The bell mouth portion is externally fitted to the block insertion portion and the stress cone portion is closely fixed to the outer periphery of the outer semiconductive layer end of the power cable,
Apply conductive paint from the outer peripheral surface of the insulating main body portion excluding the head in the terminal junction box to the portion of the outer peripheral surface of the block insertion portion that comes into contact with the bell mouth portion fitted on the outer peripheral surface. A shielding layer formed by
The terminal connection part of the electric power cable characterized by the above-mentioned. One end portion of the cylindrical covering portion is connected to the bell mouth portion,
  The power cable according to claim 1, wherein the other end portion of the cylindrical covering portion is an edge cut portion that is spaced apart and disposed above the stress cone portion and is insulated from the stress cone portion. Termination connection. The end connection part of the power cable according to claim 1 or 2, wherein both ends of the internal electrode are rounded. A method of assembling a terminal connection portion of a power cable according to claim 1,
The insulating reinforcement block is formed by a rubber elastic body that extends in the diameter expansion direction,
Around the conductor connection portion where the embedded conductor and the cable conductor are joined, the insulating reinforcement block whose diameter has been expanded in advance is disposed,
Then, after joining the power cable conductor to one end of the embedded conductor,
The block insertion part is arranged in the insulation reinforcing block , the bell mouth part is externally fitted to the outer peripheral surface of the block insertion part, and the internal electrode is covered on the conductor connection part,
Next, the method for assembling the terminal connection portion of the power cable , wherein the insulation reinforcing block is reduced in diameter and is attached to the outer periphery of the conductor connection portion so as to be covered.

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