JP5337770B2 - Power cable connection - Google Patents

Description

  The present invention relates to a power cable connecting portion for directly connecting a power cable to an electric device such as a transformer or a switch.

  2. Description of the Related Art Conventionally, an apparatus direct connection type cable connection portion that is directly attached to an apparatus is used for connection between an open / close apparatus such as a gas insulated switchgear (GIS) and a power cable (for example, FIG. 4 of Patent Document 1). reference).

  The conventional power cable connecting portion shown in Patent Document 1 includes a main body cylinder portion into which an end portion of the power cable is inserted from an opening at the lower end, and a front end portion that branches horizontally into two at the upper portion of the main body cylinder portion. And a connector main body formed in a T shape with a branching cylinder portion having an insulating property opened at.

  A bushing on the device side is fitted into one branch tube portion of the connector body. An insulating plug is attached to the other branch cylinder.

  In the connector main body, an inner conductor protruding from a bushing disposed in one branch cylinder portion is fixed to a compression terminal connected to a cable conductor in a power cable inserted from the lower end side of the main body cylinder portion.

  FIG. 1 is a view showing the vicinity of the lower end portion of the above-described conventional power cable connecting portion. In addition, a shown in FIG. 1 shows an equipotential line when power is applied to the power cable. The equipotential line a is displayed only in a certain range at both the upper end and the lower end.

  In the power cable connecting portion 1, the main body cylinder portion 3 of the connector main body includes an inner semiconductive layer 3a covering the connection portion between the cable conductor and the compression terminal, an insulating layer 3b covering the inner semiconductive layer 3a, and an insulating layer 3b. And an external semiconductive layer 3c for covering. These are formed of a rubber material such as ethylene propylene rubber (EP rubber) or silicone rubber, and are integrally formed by molding.

  An opening 1 a is formed at the lower end 3 d of the main body cylinder portion 3. The power cable 20 is inserted into the main body cylinder portion 3 through the opening 1a with the outer peripheral surface of the cable insulator 24 covered with an adapter (spacer).

  The lower end 3d is formed by a cylindrical outer semiconductive layer 3c. The outer diameter of the lower end portion 3 d is smaller than the outer diameter of the upper portion of the main body cylinder portion 3. In other words, the outer semiconductive layer 3c is inclined such that the outer diameter increases from the lower end 3d fitted on the outer peripheral surface of the adapter 5 to the outer periphery corresponding to the vicinity of the lower end of the inner semiconductive layer 3a toward the upper end. That is, it has a shape rising from the lower end 3d.

  The end of the power cable 20 covered with the adapter 5 is stepped so that the cable conductor (not shown), the cable insulator 24, and the cable external semiconductive layer are exposed from the front end side of the power cable.

  The adapter 5 is disposed on the outer periphery of the cable insulator 24 across the outer periphery of the cable external semiconductive layer in a state where the power cable 20 is inserted into the main body cylinder portion 3 of the connector main body. The adapter 5 is arranged inside the lower end portion 3d made of the outer semiconductive layer 3c, and the semiconductive layer 5a formed with a bell mouth shape on the upper end side, and the semiconductive layer 5a connected to the semiconductive layer 5a. And an insulating layer 5b formed on the upper end side of the substrate. The semiconductive layer 5a is disposed across the outer periphery of the cable outer semiconductive layer and the outer periphery of the cable insulator 24 so as to be in contact with the cable outer semiconductive layer, rises from the outer peripheral surface of the cable insulator 24, and is semiconductive. The inner diameter of the layer 5a is formed so as to expand toward the tip side. With this configuration, in the power cable connection portion 1, the electric field concentration at the tip of the cable external semiconductive layer is relaxed, and the dielectric strength in the power cable connection portion 1 is maintained.

Japanese Utility Model Publication No. 2-49320

  By the way, as shown in FIG. 1, in the conventional power cable connecting portion 1, the tip portion 5 c of the semiconductive layer 5 a of the adapter (spacer) 5 rising from the outer peripheral surface of the cable insulator 24 is power rising from the outer peripheral surface of the adapter 5. The cable connection portion 1 is located below the rising base end portion (rising portion) 4 of the external semiconductive layer 3c. The rising proximal end portion 4 is located on the inner peripheral surface of the main body cylinder portion of the connector main body.

  For this reason, the external semiconductive layer 3c of the connector main body in the power cable connecting portion 1 is configured to rise from the outer surface of the insulating layer 5b located above the semiconductive layer 5a in the adapter 5. When assembling the power cable connecting portion 1, it is necessary to insert an adapter (spacer) 5 covered with the power cable 20 into the main body cylinder portion 3 of the connector body. Since both the adapter (spacer) 5 and the connector main body are made of rubber, this operation is an operation for fitting rubbers together, that is, an operation for fitting soft objects. For this reason, compared with the fitting of a hard thing and a soft thing (for example, fitting of the cable insulator 24 and the adapter (spacer) 5), the interface between the adapter 5 and the connector body after assembly, that is, the outer periphery of the adapter 5 There is a possibility that a minute air layer may remain at the interface between the connector body and the inner periphery of the main body cylinder portion 3 of the connector body. When this air layer rises and remains at the position of the base end portion 4, the outer semiconductive layer 3c (here semiconductive rubber), the insulating layer 3b (here insulating rubber), and the air layer of the main body cylinder portion 3 of the connector body A triple junction (triple junction) T is formed.

  If power is applied to the power cable connecting portion 1 in a state where such a triple junction T is formed, an electric field concentrates on the triple junction T, and partial discharge may occur. Further, due to variations in assembly work such as the skill of the operator, the air layer may remain and partial discharge may occur.

  The present invention has been made in view of such a point, and the power cable can be stably stabilized without concentrating electrical stress on the rising portion of the external semiconductive layer of the connector body rising from the outer peripheral surface of the spacer covering the power cable. It aims at providing the power cable connection part which can be connected to an apparatus.

One aspect of the power cable connecting portion of the present invention includes an end portion of a power cable that is stripped and exposes a cable conductor, a cable insulator, and a cable outer semiconductive layer from the front end side, and an outer periphery of the cable insulator. A cylindrical spacer disposed across the outer semiconductive layer of the cable, and a rubber connector body having a cable insertion port for inserting an end of the power cable together with the spacer, the spacer Is disposed across the outer peripheral surface of the cable outer semiconductive layer and the outer peripheral surface of the cable insulator so as to be in contact with the cable outer semiconductive layer, and has a bell mouth-shaped tip. and parts, wherein an insulating rubber portion provided continuously to the distal end side of the semiconductive rubber portion, the insulating rubber part, of the cable conductor in position abutting the end surface of the cable insulation Is disposed so as to cover the outer peripheral end and said cable insulator, said connector body, the external covering and the internal semi-conductive portion and an insulating portion for covering the inner semiconducting portion, the outer circumferential surface of the insulating portion A semiconductive portion, and the external semiconductive portion has a rising portion that rises so that an inner diameter increases toward the distal end side of the power cable, and the rising portion is an inner peripheral surface of the connector body. The external semiconductive portion has a rear end portion constituting the rear end portion of the connector body, and an inner peripheral surface thereof is in close contact with an outer peripheral surface of the semiconductive rubber portion, In the inner peripheral surface, the inner peripheral surface of the rear end portion of the outer semiconductive portion, the inner peripheral surface of the insulating portion, and the inner peripheral surface of the inner semiconductive portion are formed to be flush with each other. The rising portion is on the rear end side from the front end of the semiconductive rubber portion. Position, and the outer peripheral surface of the semiconductive rubber portion, the inner peripheral surface of the outer semiconductive portions are disposed astride the inner peripheral surface of the insulating portion, a configuration.

  According to the present invention, the power cable can be stably connected to a device without electrical stress being concentrated on the rising portion of the external semiconductive layer of the connector body rising from the outer peripheral surface of the spacer covering the power cable.

The figure which shows the lower end part vicinity in a power cable connection part at the time of the power application of the conventional power cable connection part Sectional drawing which shows the structure of the power cable connection part which concerns on one embodiment of this invention A diagram showing the distribution of equipotential lines near the lower end when power is applied to the power cable connection

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

  In FIG. 2, the principal part structure of the power cable connection part 100 which concerns on one embodiment of this invention is shown. Note that the power cable connecting portion 100 shown in FIG. 2 is an electric device (not shown) and electric power whose performance and shape of connection with other devices are defined by standards such as IEEE, etc., such as transformers and switches. An example of a T-connector that connects the cable 20 will be described.

  The power cable connection unit 100 includes a power cable 20 and a T-shaped connector main body 140 having a cable insertion port 130 into which the power cable 20 is inserted together with the openings 110 and 120.

  The end portion of the power cable 20 is stripped to a predetermined length, so that the cable conductor 22, the cable insulator 24, the cable outer semiconductive layer 26, and the cable sheath (not shown) are arranged from the front end side of the power cable 20. Exposed in order.

  At the end portion of the power cable 20, the outer peripheral surfaces of the exposed base end portion of the cable conductor 22, the cable insulator 24, and the tip end portion of the cable outer semiconductive layer 26 are covered with a spacer 160. The end portion of the power cable 20 is inserted into the cable insertion opening 130 that opens at the rear end (lower end in FIG. 2) of the connector main body 140 together with the spacer 160.

  The cable conductor 22 is connected to a conductor connection terminal 150 formed by cutting a metal such as copper.

  In the conductor connection terminal 150, a flat portion 151 is formed so as to protrude upward from a portion where the cable conductor 22 is compression-connected. The flat portion 151 is disposed in the connector main body 140 between the opening portions 110 and 120 that open in a direction orthogonal to the axial direction of the power cable and orthogonal to the opening direction of the opening portions 110 and 120. Specifically, the flat part 151 is arrange | positioned inside the branch cylinder parts 140b and 140b.

  The flat portion 151 has a through hole (not shown) penetrating in the axial direction of the branch tube portion 140b, and a bushing (not shown) on the device side inside one of the openings 110 and 120 of the branch tube portions 140b and 140b. ) Is inserted, the inner conductor (not shown) protruding in the axial direction of the bushing is passed through the through hole of the flat portion 151 so that the power cable is not pulled out. As a result, the cable conductor 22 is connected to the high-voltage conductor of the electrical device in the connector main body 140.

  Although not shown, an insulating plug is detachably attached to the other opening of the openings 110 and 120.

  The spacer 160 is a cylindrical body made of rubber, and is formed integrally with the semiconductive rubber portion 161 and the semiconductive rubber portion 161 at the front end side (corresponding to “the front end side of the power cable 20”). And an insulating rubber portion 162. The spacer 160 is disposed on the outer periphery of the cable insulator 24 across the outer periphery of the cable outer semiconductive layer 26. The semiconductive rubber portion 161 constitutes the base end side of the spacer 160 (corresponding to “the rear end side of the power cable 20”), and the cable external semiconductive layer 26 is in contact with the cable external semiconductive layer 26. Between the outer peripheral surface of the cable insulator 24 and the outer peripheral surface of the cable insulator 24.

  The front end portion of the semiconductive rubber portion 161 is formed in a bell mouth shape, and is formed so that the inner diameter of the semiconductive rubber portion 161 increases from the outer peripheral surface of the cable insulator 24 toward the front end side.

  In the spacer 160, the insulating rubber portion 162 is disposed on the outer peripheral surface of the power cable 20 so as to cover the cable insulator 24 and a part of the cable conductor 22 exposed from the tip of the cable insulator 24.

  The insulating rubber portion 162 is connected to the bell mouth-shaped tip portion 161 a of the semiconductive rubber portion 161, and the base end surface of the insulating rubber portion 162 has a shape along the opening shape on the tip side of the semiconductive rubber portion 161. It is. The semiconductive rubber portion 161 and the insulating rubber portion 162 are formed of a rubber material such as ethylene propylene rubber (EP rubber) or silicone rubber, and are integrally formed by molding.

  The connector main body 140 has a straight cylindrical main body tube portion 140a into which the end portion of the power cable 20 is inserted from a cable insertion port 130 formed at the rear end, and a horizontal branch at the upper portion of the straight portion. The branched cylindrical portions 140b and 140b having insulating properties that open at the tip end portions are formed in a T shape. The connector body 140 includes an internal semiconductive portion 142, an insulating portion 144 that covers the internal semiconductive portion 142, and an external semiconductive portion 146 that covers the insulating portion 144. The connector body 140 is made of rubber formed of a rubber material such as ethylene propylene rubber (EP rubber) or silicone rubber. The internal semiconductive portion 142, the insulating portion 144, and the external semiconductive portion 146 are integrally formed by molding. Is formed. The internal semiconductive portion 142 and the external semiconductive portion 146 are formed of semiconductive rubber in FIG. 2, but the semiconductive conductivity is sufficient if it has a predetermined function as a power cable connecting portion. It is not specified in particular. The same applies to the semiconductive rubber portion 161 of the spacer 160.

The connector main body 140 defines a back side portion of the cable insertion opening 130 that opens at the rear end, and a cylindrical internal semiconductive portion 142 that covers a connection portion between the power cable 20 and the conductor connection terminal 150, It has a T-shaped cross section that covers the semiconductive portion 142 and has a cylindrical insulating portion 144, and an external semiconductive portion 146 that covers the outer peripheral surface of the insulating portion 144.

  The internal semiconductive portion 142 is provided in the linear insulating main body portion 144a of the insulating portion 144 in the main body cylindrical portion 140a of the connector main body 140, and the conductor connecting terminal 150 and the cable are connected with the flat portion 151 protruding from the upper surface. A connection portion with the conductor 22 is covered.

  The internal semiconductive portion 142 is in close contact with the outer peripheral surface of the distal end portion of the insulating rubber portion 162 in the spacer 160 covering the power cable 20 inserted from the rear end of the insulating main body portion 144a.

  The insulating main body portion 144 a of the insulating portion 144 covers the outer periphery of the internal semiconductive portion 142 and the outer peripheral surface of the insulating rubber portion 162 other than the portion inserted into the internal semiconductive portion 142 in the spacer 160 and the outer periphery of the semiconductive rubber portion 161. The tip part of is covered. The outer periphery of the insulating main body 144a has a shape narrowed downward corresponding to the shape of the external semiconductive portion 146.

In the main body cylinder portion 140a of the connector main body 140, the external semiconductive portion 146 that covers the insulating portion 144 constitutes the rear end portion 140c of the connector main body 140 at the rear end portion. On the inner peripheral surface of the main body cylinder portion 140a of the connector 140, the inner peripheral surface of the rear end portion of the outer semiconductive portion 146, the inner peripheral surface of the rear end portion of the insulating main body portion 144a, and the inner peripheral surface of the inner semiconductive portion 142. Are formed flush with each other. The rear end portion 140c of the connector main body 140, that is, the inner peripheral surface of the rear end portion of the external semiconductive portion 146, is the outer peripheral surface of the semiconductive rubber portion 161 of the spacer 160 inserted into the main body cylindrical portion 140a from the cable insertion port 130. It is in close contact with.

  As shown in FIG. 2, the external semiconductive portion 146 in the main body cylinder portion 140 a of the connector main body 140 contacts at a position on the rear end side from the front end (upper end in FIG. 2) 161 a of the semiconductive rubber portion 161 of the spacer 160. The semiconductive rubber portion 161 is formed so as to stand up in a direction away from the outer peripheral surface 161b of the outer peripheral surface 161b.

  That is, the external semiconductive portion 146 constituting the outer surface of the connector main body 140 is connected to the external semiconductive portion 146 from the rising portion 146a of the outer peripheral surface 161b of the semiconductive rubber portion 161 in the spacer 160 at the rear end portion 140c of the connector main body 140. Is rising from the rising portion 146a toward the distal end side (the upper side in FIG. 2) of the power cable 20.

  Accordingly, the rising portion 146a is located on the rear end side (lower side in FIG. 2) from the front end 161a of the semiconductive rubber portion 161.

  In addition, since the rising portion 146a is also the rear end of the insulating portion 144 in FIG. 2, the rising portion 146a serves as a junction point between the lower end of the insulating portion 144 of the connector main body 140 and the external semiconductive portion 146. . That is, the rising portion 146 a of the external semiconductive portion 146 is located on the inner peripheral surface of the connector main body 140. Therefore, the rising portion 146 a is located on the outer periphery of the semiconductive rubber portion 161 of the spacer 160 in the cable connection portion 100.

When assembling the power cable connection portion 100, it is necessary to insert the spacer 160 covered with the power cable 20 into the main body cylinder portion 140a of the connector main body 140. Spacers 160, since both the connector body 1 4 0 made of rubber, the work of fitting the soft ones together. There is a possibility that a minute air layer may remain at the interface between the spacer 160 and the connector main body 40 after assembly. When this air layer remains in the rising portion 146a, the external semiconductive portion 146 (here semiconductive rubber), the insulating portion 144 (here insulating rubber), and the air layer of the main body cylinder portion 140a of the connector main body 140 come into contact with each other. A triple junction is formed.

  Since the rising portion 146a which may become a triple junction is located on the rear end side (lower side in FIG. 3) of the front end 161a of the semiconductive rubber portion 161, as shown in FIG. Electric field concentration can be prevented when the cable connection unit 100 is charged.

  FIG. 3 is a diagram showing a distribution of equipotential lines in the vicinity of the lower end portion when power is applied to the power cable connecting portion according to the embodiment of the present invention. In FIG. 3, “a” indicates an equipotential line when the power cable connection unit 100 is charged.

  As shown in FIG. 3, since the rising portion 146a is located on the rear end side (lower side in FIG. 3) with respect to the tip 161a of the semiconductive rubber portion 161, an equipotential line may wrap around the rising portion 146a. Therefore, the concentration of the electric field at the rising portion 146a can be prevented, and the occurrence of partial discharge can be prevented.

  2 and 3, the external semiconductive portion 146 of the connector main body 140 is in contact with the outer peripheral surface of the semiconductive rubber portion 161 of the spacer 160. As a result, the external semiconductive portion 146 as a shielding layer of the power cable connecting portion 100, the semiconductive rubber portion 161 of the spacer 160, and the cable external semiconductive layer 26 are in electrical contact with each other to form a ground potential.

  2 and 3, the rising portion 146a of the external semiconductive portion 146 of the connector main body 140 is the inner peripheral surface of the connector main body 140 (in FIG. 2 and FIG. 3, the inner peripheral surface of the main body cylindrical portion 140a). Located in.

  For example, the insulating portion 144 of the connector main body 140 is disposed between the outer periphery of the semiconductive rubber portion 161 of the spacer 160 and the inner periphery of the outer semiconductive portion 146 of the connector main body 140 so that the external semiconductive portion 146 In the case of a structure that does not contact the outer peripheral surface of the semiconductive rubber part 161, that is, in the case of the structure in which the external semiconductive part 146 and the semiconductive rubber part 161 are insulated, the equipotential lines are connected to the external semiconductive part 146 during power application. There is a risk of entering between the semiconductive rubber portions 161. Therefore, it is desirable that the outer semiconductive portion 146 is in contact with the outer peripheral surface of the semiconductive rubber portion 161 as in the embodiment of FIGS. In the case of such a structure, as shown in FIG. 3, it is completely shielded by the semiconductive rubber portion 161 of the spacer 160 and the external semiconductive portion 146 of the connector main body 140 and the external semiconductive portion of the connector main body 140. Since the rising portion 146a of 146 is located on the rear end side of the front end 161a of the semiconductive rubber portion 161 of the spacer 160, the electric field does not concentrate on the rising portion 146a.

  As described above, according to the present embodiment, the power cable 20 is connected to the rising portion 146a of the external semiconductive portion 146 of the connector main body 140 rising from the outer peripheral surface of the spacer 160 covering the power cable 20 without applying electrical stress. It can be connected to electrical equipment stably.

Furthermore, according to the present embodiment, when the power cable connection portion 100 assembled in the interface with the spacer 160 and the connector body 1 4 0, even if the remaining small air layer to the rising portion 146a of the outer semiconducting 146 In addition, electrical stress is not concentrated on the triple junction (rising portion 146a), and as a result, generation of partial discharge due to variation in assembly work can be eliminated. Therefore, the power cable can be stably connected to the device.

  In addition, although the power cable connection part 100 of this Embodiment was demonstrated as a T-type connector, a shape may not be restricted to a T type but an L type or a direct type connector. That is, the shape of the connector body is not limited.

  The power cable connecting portion according to the present invention has an effect that the power cable can be stably connected to a device without concentrating electrical stress on the rising portion of the outer semiconductive layer rising from the outer peripheral surface of the spacer covering the power cable. However, it is useful as a device used to connect an electric device and a power cable.

DESCRIPTION OF SYMBOLS 20 Power cable 22 Cable conductor 24 Cable insulator 26 Cable outer semiconductive layer 100 Power cable connection part 130 Cable insertion port 140 Connector main body 140c Rear end part of connector main body 142 Internal semiconductive part 144 Insulating part 144a Insulating main body part 146 External half Conductive part 146a Rising part 160 Spacer 161 Semiconductive rubber part 161a Tip of semiconductive rubber part 162 Insulating rubber part

Claims (2)

The end portion of the power cable that has been stripped to expose the cable conductor, the cable insulator, and the cable outer semiconductive layer from the tip side, and the outer periphery of the cable insulator is disposed across the cable outer semiconductive layer. A cylindrical spacer, and a rubber connector main body having a cable insertion port for inserting an end of the power cable together with the spacer,
The spacer is disposed across the outer peripheral surface of the cable outer semiconductive layer and the outer peripheral surface of the cable insulator so as to be in contact with the cable outer semiconductive layer, and has a bell mouth-shaped tip. A conductive rubber part, and an insulating rubber part connected to the tip side of the semiconductive rubber part,
The insulating rubber portion is disposed so as to cover a base end portion of the cable conductor and an outer periphery of the cable insulator at a position in contact with a distal end surface of the cable insulator,
The connector body includes an internal semiconductive portion, an insulating portion that covers the internal semiconductive portion, and an external semiconductive portion that covers the outer peripheral surface of the insulating portion,
The external semiconductive portion has a rising portion that rises so that the inner diameter increases toward the distal end side of the power cable,
The rising portion is located on the inner peripheral surface of the connector body,
The external semiconductive portion has a rear end portion constituting a rear end portion of the connector body, and an inner peripheral surface thereof is in close contact with an outer peripheral surface of the semiconductive rubber portion,
In the inner peripheral surface of the connector body, the inner peripheral surface of the rear end portion of the outer semiconductive portion, the inner peripheral surface of the insulating portion, and the inner peripheral surface of the inner semiconductive portion are formed flush with each other. A connecting part,
The rising portion is located on the rear end side from the front end of the semiconductive rubber portion,
The outer peripheral surface of the semiconductive rubber portion is disposed across the inner peripheral surface of the external semiconductive portion and the inner peripheral surface of the insulating portion.
Power cable connection. The shape of the connector main body includes a straight cylindrical main body cylindrical portion into which an end of the power cable is inserted, and a branched cylindrical portion in which the distal end portion opens horizontally and branches into two at the distal end side of the main body cylindrical portion. And a T type formed by
The power cable connection part according to claim 1.

Images