CN104316736B - Combined insulated lead for switch cabinet power-frequency and alternating-current withstand voltage test - Google Patents

Abstract

The invention discloses a combined insulated lead for switch cabinet power-frequency and alternating-current withstand voltage test, comprising a plurality of insulated leads, two wiring clamps used for being respectively and electrically connected with a tested object and a test transformer, and a plurality of two-way joints used for connecting two insulated leads. Each of the insulated leads is provided with a bare metal connection peg at each of the two ends. The rear end of at least one metal handle of each wiring clamp is provided with a jack in tight fit with the connection pegs of the insulated leads. The middle of each two-way joint is a metal conductive column, the two ends of the metal conductive column are respectively provided with a jack in tight fit with the connection pegs of the insulated leads, the metal conductive column is coated with an insulating layer, and the insulating layer extends to the outer ends of the jacks to form ladder-shaped holes for the insulating layer parts of the insulated leads to be embedded in. The insulated leads and the two-way joints are provided with external insulation and are not restricted by space and environment, other field electrical equipment does not need to be moved, and the testing efficiency and safety performance can be improved. The combined insulated lead can be assembled and disassembled freely as needed, and is convenient to operate and easy to carry.

Description

Combined insulated lead wires for power frequency AC withstand voltage test of switchgear

technical field

The invention relates to the field of power-frequency AC withstand voltage test of electrical primary equipment in a switch cabinet, in particular to a combined insulated lead wire for the power-frequency AC withstand voltage test of a switch cabinet.

Background technique

According to the "Code for Construction and Acceptance of Electrical Installation Engineering GB50254-259-1996" and "Test Regulations for Condition Maintenance of Power Transmission and Transformation Equipment DL/T393-2010" and other relevant specifications and regulations, the handcart switch and dry-type current mutual inductance in the 10kV switch cabinet The power frequency AC withstand voltage test (withstand voltage range: 30-42kV, time: 1 minute) needs to be carried out in the handover test, routine test and diagnostic test of primary equipment such as switches and busbars. Since the test transformers used are small-capacity and lightweight devices, and the cables that meet the withstand voltage requirements have large capacitance, this kind of cable can meet the test requirements, but the weight and volume are too large, which is not conducive to on-site portability and difficult to arrange. Therefore, in the actual operation process, the bare copper wire is generally used as the pressure lead between the equipment under test and the test transformer, supplemented by insulating laces and insulating rods as insulation supports to isolate the pressure lead from peripheral equipment. However, the following defects will exist in this process:

(1) Due to space constraints, when the bare copper wire is arranged, it needs to be suspended in the air to prevent the lead wire from being too close to the ground and the surrounding electrical equipment to discharge during the pressurization process.

(2) Affected by the height of the equipment under test and the test transformer, the bare copper wire should not be arranged too long, and a certain distance must be kept from the ground for insulation purposes. If the bare copper wire is too long, sag will occur due to its own weight , In this way, there will be insufficient distance to the ground, and the discharge will cause the test to fail. In the case of heavy on-site workload, such as handover acceptance test or diagnostic test, there are often seven or eight switchgears that need to be tested for power frequency withstand voltage, and even the entire switchgear cabinet needs to be tested, depending on the length of the lead wire or the space. Due to limitations, it is often necessary to change the position of the test transformer and the operation box several times to meet the test conditions.

(3) Although the distance between the bare copper wire and the ground and the surrounding electrical equipment can be appropriately increased with the help of insulating ties and insulating rods, the implementation process will be more troublesome and random, which is not conducive to standard operation and brings safety hazards to the test .

Contents of the invention

In order to overcome the above-mentioned problems caused by the use of bare copper wires as the pressurized wire and the need for air as the insulating medium, the present invention proposes a combined insulated lead wire for the power frequency AC withstand voltage test of the switchgear, which is not affected by the test space, environment and distance , can be conveniently released between the tested product and the test transformer, which can improve the test work efficiency and safety performance.

To achieve the above object, the present invention adopts the following technical solutions, including:

Several insulated leads with bare metal plug connectors at both ends;

Two terminal clamps respectively used for electrical connection with the tested object and the test transformer, each terminal clamp has at least one metal handle rear end with a socket that is tightly matched with the insulated lead plug connector;

Several two-way joints used to connect two insulated leads. The middle of the two-way joints is a metal conductive column. The two ends of the metal conductive column are provided with sockets that are tightly matched with the insulated lead plug connectors. The metal conductive column is covered with an insulating layer. The outer ends of the insertion holes at both ends of the metal conductive post are extended to form a stepped hole for the insulating layer of the insulated lead wire to partially embed.

During the test, the insulated lead wire is connected to the required length through a two-way joint, and the two ends are connected to the handle of the terminal clamp, and the test object and the test transformer are connected through the terminal clamp. Since the insulated leads and the two-way connectors are covered with an insulating layer, they can be directly installed along the ground, so the auxiliary installation of the line is more convenient, without considering the distance from other surrounding equipment, and the length can be increased arbitrarily, without moving other equipment on site.

Further, the insulating layer of the insulating lead wire and the insulating layer covered by the metal conductive post are all made of silicone rubber insulating material. The insulating layer is made of silicone rubber insulating material, and its power frequency withstand voltage can reach 50kV, and the time is 1 minute.

Preferably, the insulating layer of the bidirectional joint is an insulating cover composed of a male and a female insulating cover connected by threads, and the inlet ends of the male and female insulating covers form stepped holes at both ends of the insulating layer of the bidirectional joint, and the metal conductive posts are built into the insulating cover In the inner chamber, the inner wall of the inlet end of the male and female insulating covers has an end wall that limits the circumferential direction of the metal conductive column end. On the insulating layer at the bottom, it can effectively prevent the formation of creeping discharge at the interface, which will lead to the failure of the test.

Further, the metal conductive pillar built in the insulating cover is covered with an insulating layer.

The beneficial effects of the present invention are:

1. The insulated leads that make up the pressurized leads and the two-way joints that connect the insulated leads have their own external insulation, and the insulation strength is higher than the requirements of the field test, so they can be released at will, not limited by space and environment, and do not need to move other electrical appliances on site. Equipment, and it is not necessary to take other insulation measures such as insulating ties or insulating rods, which can improve test efficiency and safety performance.

2. The length of the pressurized lead can be freely assembled and disassembled according to the needs, and the appropriate length of the pressurized lead can be selected according to the distance between the test product and the test transformer, which is easy to assemble and carry. The ladder-shaped hole structure at both ends of the bidirectional joint allows the insulating layer of the bidirectional joint to be superimposed and covered on the insulating layer at the end of the insulated lead wire, which coincides with a certain length of the insulated lead itself, which can avoid surface discharge at the interface, and has good insulation performance. It solves the problem of weak insulation at the junction between leads. At the same time, in the preferred solution of the present invention, the special inner cavity design of the male and female insulating covers of silicone rubber can hold the metal conductive posts well, and at the same time, when the male and female insulating covers are engaged with each other, the male and female insulating covers can Fixed on the metal conductive post.

3. The location of the test transformer and the operation box can be selected as the nearest place to the power point. In the case of many tested products, the length of the press lead wire can be increased or decreased, and there is no need to move the test transformer and the operation box again. position, which reduces the work intensity of high-voltage electrical testers and improves work efficiency.

Description of drawings

Fig. 1 is a schematic diagram of an insulated lead junction according to the present invention.

Fig. 2 is a schematic diagram of the structure of the wiring clip of the present invention.

Fig. 3 is a schematic diagram of the structure of the bidirectional joint of the present invention.

Fig. 4 is a structural schematic diagram of another embodiment of the bidirectional joint of the present invention.

Fig. 5 is a structural schematic diagram of the assembly state of the bidirectional joint and the insulated lead wire of the present invention.

The meanings of the marked symbols in the figure are as follows:

1, 1a, 1b—insulated lead wire 11—copper core 12—plug connector 13—insulation layer 2—connection clip 21—jaw 22—handle 23—jack 24—insulation layer 3—two-way connector 31—metal conductive column 311, 312 - jack 313 - insulating layer 32 - insulating layer 321 - male insulating cover 3211 - inlet port 3212 - end wall 322 - female insulating cover 3221 - inlet port 3222 - end wall 33 - stepped hole 34 - inner chamber of insulating cover

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are only some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Refer to Figure 1 for the structure of the insulated leads. The length of the insulated lead wire 1 is about 2 meters, the middle copper core 11 of the insulated lead wire 1 is covered with an insulating layer 13 , and there are exposed metal plug connectors 12 at both ends of the insulated lead wire 1 . The front end of the plug joint 12 is provided with an annular groove 121 to increase the frictional resistance with the connector and increase the tension force.

Refer to Figure 2 for the wiring clip structure. The front end of the terminal clamp 2 is a jaw 21 connected to the high-voltage end of the test product or the test transformer, and the rear end of a metal handle 22 has a jack 23 that is tightly matched with the insulated lead plug connector 12. The metal handle 22 is covered with an insulating layer 24 . Jacks 23 can also be set at the rear ends of the two metal handles to facilitate the connection of any jack with the insulated lead wire 1 .

See Figure 3 for the structure of the bidirectional joint. In the middle of the two-way joint 3 is a metal conductive column 31, and the two ends of the metal conductive column 31 are provided with jacks 311, 312 that are closely matched with the insulated lead plug connector 12. The metal conductive column 31 is covered with an insulating layer 32, and the insulating layer 32 is connected to the metal conductive column. The outer ends of the insertion holes 311 and 312 at both ends extend to form a stepped hole 33 into which the insulation layer 13 of the insulated lead wire is partially embedded. When the two ends of the bidirectional connector 3 are connected with the insulated lead 1 , the insulating layer at the stepped hole 33 at least partially covers the insulating layer 13 at the end of the insulated lead 1 .

The insulating layer 32 of the bidirectional joint 3 may also adopt a split structure, as shown in FIG. 4 . The insulating layer 32 is composed of two male and female insulating covers 321 and 322 which are connected by threads. The metal conductive post 31 is built in the inner chamber 34 of the insulating cover, and the metal conductive post 31 is covered with an insulating layer 313 at the same time. The inlet ends 3211 , 3221 of the male and female insulating covers 321 , 322 form stepped holes 33 at both ends of the insulating layer 32 of the bidirectional connector 3 . The inlet end 3211,3221 inner wall of male and female insulating cover 321,322 has the end wall 3212,3222 that limits the circumferential direction of metal conductive column 31 end, when locking male and female insulating cover 321,322, can put metal The conductive post 31 is fixed in the insulating cover chamber 34 , and the jacks 311 , 312 at both ends of the metal conductive post are arranged concentrically with the inlet ends 3211 , 3221 of the male and female insulating covers 321 , 322 . When the two ends of the bidirectional joint 3 are connected with the insulated leads 1a, 1b, the inlet ends 3211, 3221 of the male and female insulating covers 321, 322 cover the insulating layer 13 at the ends of the insulated leads. Its assembly method is shown in Figure 5, two insulated lead wires 1a, 1b are respectively connected to the two ends of the two-way lead post 31 of the two-way joint through plug connectors, and the male and female insulating covers 321 and 322 are screwed tightly, and the male and female insulating covers are connected to each other. The end walls 3212, 3222 of the inlet end are close to the end of the metal conductive column 31, and the inlet ends 3211, 3221 of the male and female insulating covers are respectively covered on the insulation layers of the insulated leads 1a, 1b.

The insulation layer 13 of the insulated lead wire 1, the insulation layer 32 of the bidirectional joint 3, and the insulation covers 321 and 322 are all made of silicone rubber insulation materials with good voltage resistance. The insulating layer 313 of the built-in metal conductive column 31 and the insulating layer 24 covered by the handle end of the terminal clamp 2 can be made of common insulating materials.

The present invention requires several insulated lead wires 1 , two clamps 2 and several bidirectional joints 3 . During the test, the insulated lead wires are electrically connected to the required length with a two-way joint, and then the insulated lead wires at both ends are electrically connected to the terminal clamps through the plug joints, and the terminal clamps at both ends are respectively clamped on the corresponding terminals of the equipment under test and the test transformer. end, you can perform test operations.

Claims (4)

1. Combined insulated lead wires for power frequency AC withstand voltage test of switchgear, including several insulated lead wires (1), with exposed metal plug connectors (12) at both ends of the insulated lead wires (1); it is characterized in that it also includes: Two connection clamps (2) respectively used for electrical connection with the test object and the test transformer, each connection clamp (2) has at least one metal handle (22) at the rear end with a socket ( twenty three); Several bidirectional connectors (3) for connecting two insulated lead wires (1), the middle of the bidirectional connectors (3) is a metal conductive column (31), and the two ends of the metal conductive column (31) are provided with metal plug connectors (12) Tightly fitted sockets (311, 312), the metal conductive post (31) is covered with an insulating layer (32), and the insulating layer (32) extends to the outer ends of the two ends of the metal conductive post (311, 312) to form an insulated lead wire (1) The insulating layer (13) is partially embedded in the stepped hole (33). 2. The combined insulated lead wire for power frequency AC withstand voltage test of switchgear according to claim 1, characterized in that: the insulating layer (13) of the insulated lead wire (1), the insulating layer ( 32) are all made of silicone rubber insulating material. 3. according to claim 1 or 2 described switchgear power frequency AC withstand voltage test combination insulated lead wire, it is characterized in that: the insulation layer (32) of bidirectional joint (3) is by the male and female insulating cover that is connected by screw thread (321,322) the insulating cover that forms, and the entrance end (3211,3221) of male and female insulating cover forms the step-shaped hole (33) of two-way joint (3) insulating layer (32) two ends, and metal conductive column (31) is built-in In the inner chamber (34) of the insulating cover, the inner walls of the inlet ends (3211, 3221) of the male and female insulating covers have end walls (3212, 3222) that limit the circumferential direction of the ends of the metal conductive columns (31), and are used as two-way joints. (3) When the insulated lead wires (1) are connected at both ends, the inlet ends (3211, 3221) of the male and female insulating covers cover the insulating layer (13) at the ends of the insulated lead wires. 4. The combined insulated lead wire for power frequency AC withstand voltage test of switchgear according to claim 3, characterized in that: the metal conductive column (31) built in the insulating cover is covered with an insulating layer (313).