Device for preventing 110kV outdoor full-prefabricated dry type cable terminal from being heated and mounting method of device

Abstract

The invention relates to a device for preventing a 110kV outdoor full-prefabricated dry type cable terminal from being heated and a mounting method of the device, and belongs to the technical field of design, mounting and maintenance of power systems. The device comprises two copper-aluminum transitional equipment wire clamps, wherein the copper-aluminum transitional equipment wire clamps comprise pressure connection pipes and copper-aluminum transitional plates arranged below the pressure connection pipes; the copper-aluminum transitional plates comprise aluminum base plates and copper surface layers closely attached to copper wiring terminals; a copper wing plate is arranged on the copper-aluminum transitional plate of one copper-aluminum transitional equipment wire clamp; a copper wing plate attached to the other side wall of the copper wiring terminal is arranged on the copper-aluminum transitional plate of the other copper-aluminum transitional equipment wire clamp; the two copper-aluminum transitional equipment wire clamps are fastened with the copper wiring terminals through fasteners to form a whole; fork type heat shrink tubes are arranged outside the copper wiring terminals and the two copper-aluminum transitional equipment wire clamps in a sleeving manner. The device is simple and effective in structure, can prevent joints of a wire outlet terminal of the dry type cable terminal and the copper-aluminum transitional equipment wire clamps from being oxidized, heated and blackened, and can realize a total life cycle.

Description

technical field [0001] The invention relates to a device for preventing heating of a 110kV outdoor fully prefabricated dry-type cable terminal and an installation method thereof, belonging to the technical field of power system design, installation and maintenance. Background technique [0002] At present, the protruding terminal of the 110kV outdoor fully prefabricated dry-type cable terminal is made of copper. When connecting to the overhead aluminum conductor, the connection method of the conventional copper-aluminum transition equipment clamp is generally used, and the copper-aluminum transition equipment clamp is then connected to the wire jumper. . According to the operating experience in various places, the phenomenon of heat and blackening at the connection between the protruding terminal and the conventional copper-aluminum transition equipment clamp is relatively common through infrared temperature measurement, which affects the normal operation of the line. The p...

AI Technical Summary

Problems solved by technology

So far, the country has not issued technical regulations for crimping copper and aluminum terminals for power cables of 110kV and above

[0004] 2. Summary of "Analysis of 110kV full-dry outdoor cable terminal board heating causes and countermeasures [J] (Cable Technology, 2015.1: 34-35, Zhu Fawan. Shenzhen Power Supply Bureau Co., Ltd.)" summary: First, the installation of the cable clamp is not correct. Second, the design is unreasonable, the flexible dry-type outdoor cable terminal is not rigidly fixed, swings with the wind, and the protruding terminal is not on the same plane as the junction of the copper-aluminum transition equipment clamp, and there is a gap. The contact resistance becomes larger and heats up; the third is that there is no construction platform under the cable terminal, and the connection between the protruding terminal and the copper-aluminum transition equipment clamp is not on the same plane, so the installation is difficult, so that the bolts are not installed tightly, gaps appear, and the contact area is small. Make the contact resistance increase and generate heat

[0005] 3. At present, most of the protruding terminals of all 110kV outdoor fully prefabricated dry-type cable terminals are made of copper with flat feet, and there are two reserved fixing holes, which are connected with a pair of conventional copper-aluminum transition equipment clamps. The copper-aluminum transition equipment clip is connected with the wire jumper, and the wire jumper is connected with the wire tension string; The wire clip will be affected by the swaying force; in addition, the wire jumper will transfer the breeze vibration frequency and energy of the overhead wire to the copper-aluminum transition equipment wire clip and the protruding terminal of the dry cable terminal. Over time, the nut connecting the bolt will Looseness occurs so that the contact surface between the conventional copper-aluminum transition equipment clamp and the protruding terminal of the dry-type cable terminal becomes smaller, the contact resistance increases, and further heat generation, oxidation and blackening

At present, due to market competition, the copper surface of the copper-aluminum transition equipment clamps on the market is mostly not tinned in order to keep costs down. one

[0007] 5. In GB50168-2006 "Code for Construction and Acceptance of Cable Lines", the section of the cable connection fittings should be 1.2 to 1.5 times the section of the core, and the section of the cable is 630mm 2 、800mm 2 and 1000 mm 2 The corresponding calculation section is 756mm 2 、960mm 2 and 1200mm 2 , the calculated value of the contact surface is 6029mm 2 、7406mm 2 and 10158mm 2 , the cable protruding terminal contact surface is 7917mm respectively 2 、11310mm 2 and 15551mm 2 , the overhead side contact surface is 8470mm 2 、9470mm 2 and 10010mm 2 , the above calculated value does not consider the tin plating factor and the contact surface removed by the fixing hole

At present, in order to reduce costs due to market competition, the theoretical contact surface of the copper surface of the copper-aluminum transition equipment clamp on the market is insufficient (the one-side contact surface designed by individual manufacturers is 90mm×50mm=4500mm 2 ) or the theoretical contact surface is sufficient but the operating experience contact surface is insufficient, which is also one of the reasons for the phenomenon of heat and blackening at the connection between the protruding terminal and the conventional copper-aluminum transition equipment clamp

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