CN216051861U

CN216051861U - Secondary circuit live-line sealing device of current transformer

Info

Publication number: CN216051861U
Application number: CN202122398655.7U
Authority: CN
Inventors: 杨海; 周鸣中; 李圳培; 刘思思; 田朋云; 杨澜; 王丹
Original assignee: China Yangtze Power Co Ltd
Current assignee: China Yangtze Power Co Ltd
Priority date: 2021-09-30
Filing date: 2021-09-30
Publication date: 2022-03-15
Anticipated expiration: 2031-09-30

Abstract

A secondary circuit live-line sealing device of a current transformer comprises a first terminal row, a second terminal row, CT test terminals, two short connecting pieces and four short connecting pieces, wherein the first terminal row is provided with eight CT test terminals which are mutually arranged and divided into four groups which are connected with the two short connecting pieces to form four test terminal groups, the second terminal row is provided with four CT test terminals which are mutually arranged and connected with the four short connecting pieces, four outlet sides of the four test terminal groups are electrically connected with the second terminal row through CT cables, cables led out from the other four outlet sides of the four test terminal groups are connected with a protection device, the test terminals in the second terminal CT row are started by pushing metal pieces in the test terminal groups to slide to conduct or disconnect fixed conductors, a protection device to be tested is completely isolated from a live secondary circuit to electrically seal the secondary circuit of the current transformer, safe and reliable, easy operation is convenient.

Description

Secondary circuit live-line sealing device of current transformer

Technical Field

The utility model belongs to the technical field of current transformer calibration, and relates to a current transformer secondary circuit live-line sealing device.

Background

When the relay protection and safety automatic device is overhauled, a secondary circuit of the current transformer needs to be opened to check the null shift and the precision of the current transformer. In general, when a stabilizing device and an out-of-step disconnection device are overhauled, a primary system does not stop running, a secondary circuit of the current transformer is electrified all the time during the overhaul period, and the secondary circuit of the current transformer needs to be electrified and sealed. The operating personnel often adopt CT shorting strips or test shorting bars to carry out live-line sealing on the CT body side phoenix alternating current terminals.

Most of the existing protection devices are in dual configuration, and the requirement of a power grid on the reliability of power supply is higher and higher. The calibration work of the protection device which is carried out by a primary system without power failure is more and more, and the secondary circuit of the current transformer needs to be sealed with power on frequently.

And (3) sealing by using a CT short-circuit piece, namely, firstly installing a test bolt at the position of the CT test jack, then installing the CT short-circuit piece, and finally screwing the bolt to firmly seal. Because the test bolt and the CT short-circuit piece are made of exposed conductors and need to be installed by using special tools, inconvenience is brought to work, workers need to operate carefully, and risks such as short circuit, grounding, electric shock of the workers and the like are easily caused.

When the test shorting stub is used for sealing, a worker needs to vertically press the test shorting stub into the CT test jack, the operation is slightly improper, the test jack is deformed and falls off, and risks such as short circuit, grounding and electric shock of the worker are easily caused. The test short-circuit wire is in poor contact with the test jack or is mistakenly touched in the checking work, so that the open circuit of the secondary circuit of the electrified current transformer is easily caused, and the safety of equipment and life is endangered.

The situation that N lines have short connecting pieces often exists on the site, the short connecting pieces cannot be used for sealing a secondary circuit of the current transformer, and the test short connecting lines cannot be used due to the fact that test jacks are occupied.

Disclosure of Invention

The utility model aims to solve the technical problem of providing a secondary circuit live-line sealing device of a current transformer, wherein eight CT test terminals which are arranged mutually are arranged on a first terminal row and are divided into four groups to be connected with two short-circuit pieces to form four test terminal groups, four CT test terminals which are arranged mutually are arranged on a second terminal row and are connected with four short-circuit pieces, four wire outlet sides of the four test terminal groups are electrically connected with the second terminal row through CT cables, cables led out from the other four wire outlet sides of the four test terminal groups are connected with a protection device, a metal piece in the test terminal groups is pushed to slide to conduct or break a fixed conductor, so that the CT test terminals in the second terminal row are started, the protection device to be tested is completely isolated from a live secondary circuit, and the secondary circuit of the current transformer is live-line sealed, safe, reliable, simple and convenient to operate.

In order to solve the technical problems, the technical scheme adopted by the utility model is as follows: a secondary circuit live-line sealing device of a current transformer comprises a first terminal row, a second terminal row, a CT test terminal, two short connecting pieces and four short connecting pieces; the first terminal row is provided with eight CT test terminals which are mutually arranged, and every two CT test terminals are in a group and are connected with four two-short connecting pieces to form four test terminal groups; four CT test terminals which are mutually arranged are arranged on the second terminal row, and the four short connecting pieces are connected with the four CT test terminals; the CT cable is electrically connected with the CT test terminals on the first terminal row and the second terminal row.

The incoming line side and the outgoing line side of the CT test terminal are provided with wiring holes, wiring screws and test jacks are arranged at two ends of the upper side of the CT test terminal respectively, a metal piece is arranged in the middle of the CT test terminal, and fixed conductors are arranged on two sides of the metal piece.

The metal piece is laterally in sliding conduction with the fixed conductor.

And four outlet sides of the four test terminal groups are connected with the inlet sides of the four CT test terminals on the second terminal row through four CT cables, and cables led out from the other four outlet sides of the four test terminal groups are connected with the protection device.

The utility model has the beneficial effects that:

the metal piece in the test terminal group slides to conduct the fixed conductor, so that the CT test terminal in the second terminal row is started, the protection device to be tested is completely isolated from the electrified secondary circuit, the electrified sealing is carried out on the secondary circuit of the current transformer, and the cost is low.

The device has the advantages of clear principle, simple wiring, simple operation, easy operation and convenient and quick completion of the live sealing operation of the secondary circuit of the current transformer.

When the protection device normally operates, the protection device operates in a current loop wiring mode, the CT test terminal and the CT cable in the second terminal row are not electrified, and a double-break anti-misoperation design is formed.

Two short connecting pieces are adopted for short connection, and when the sealing device is used, live sealing can be easily completed only by pushing a metal piece.

The expansion performance is good, and the method is suitable for the charged sealing of the secondary circuits of a plurality of groups of alternating current transformers.

Drawings

The utility model is further illustrated by the following figures and examples.

Fig. 1 is a schematic view of the connection of a first terminal row with a second terminal row and a protection device according to the utility model.

FIG. 2 is a schematic structural diagram of a CT test terminal according to the present invention.

Fig. 3 is a schematic top view of fig. 2.

In the figure: the test device comprises a first terminal row 1, a second terminal row 2, a CT test terminal 3, a wiring hole 31, a wiring screw 32, a test jack 33, a metal piece 34, a fixed conductor 35, a two-connection short tab 4, a four-connection short tab 5, a CT cable 6 and a protection device 7.

Detailed Description

As shown in fig. 1 to 3, a secondary circuit live-line sealing device for a current transformer comprises a first terminal row 1, a second terminal row 2, a CT test terminal 3, a two-connection short tab 4 and a four-connection short tab 5; the first terminal row 1 is provided with eight CT test terminals 3 which are mutually arranged, and each two CT test terminals are in a group and are connected with four two short connecting tabs 4 to form four test terminal groups; four CT test terminals 3 which are mutually arranged are arranged on the second terminal row 2, and a four-connection short-circuit piece 5 is connected with the four CT test terminals 3; the CT cables 6 are electrically connected to the CT test terminals 3 on the first terminal row 1 and the second terminal row 2. When the device is used, the sliding metal piece 34 in the test terminal group is pushed to slide to conduct or disconnect the fixed conductor 35, so that the CT test terminal 3 in the second terminal row 2 is started, the protection device 7 to be tested is completely isolated from the electrified secondary circuit, and the electrified sealing-in is carried out on the secondary circuit of the current transformer, so that the device is safe and reliable, and is simple and convenient to operate.

In a preferred scheme, wiring holes 31 are formed in the wire inlet side and the wire outlet side of the CT test terminal 3, wiring screws 32 and test jacks 33 are respectively formed in the two ends of the upper side of the CT test terminal, a metal piece 34 is arranged in the middle of the CT test terminal, and fixed conductors 35 are arranged on the two sides of the metal piece 34.

In a preferred embodiment, the metal member 34 is laterally slidably connected to the fixed conductor 35.

In a preferred scheme, four outgoing lines of the four test terminal groups are connected with incoming lines of the four CT test terminals 3 on the second terminal row 2 through four CT cables 6, and cables led out from the other four outgoing lines of the four test terminal groups are connected with a protection device 7.

In the following, the procedure is as follows,

preferably, 8 CT test terminals 3 are mounted in the first terminal row 1 and 4 CT test terminals 3 are mounted in the second terminal row 2. Secondary loop incoming cables IA, IB, IC and IN IN the first terminal row 1 are respectively accessed from the left side wiring holes 31 of No. 1, No. 3, No. 5 and No. 7 terminals, and wiring screws 32 are screwed; the group of current cables Ia, Ib, Ic and In are respectively connected into the protection device 7 from the wiring holes 31 on the right sides of No. 1, 3, 5 and 7 terminals; the right-hand connection hole 31 of the

terminal number

2, 4, 6, 8 is inserted into the A, B, C, D terminal left-hand connection hole 31 of the second terminal row 2 via the CT cable 6 and the connection screw 32 is tightened.

Preferably, in the first terminal row 1, 4 two-short connecting tabs 4 are respectively installed in the test jacks 33 on the left sides of

terminals

1, 2, 3, 4, 5, 6, 7, 8, and are firmly fastened by screws. In the second terminal row 2, 1 quadruple shorting tab 5 is mounted in the test socket 33 on the right side of the A, B, C, D # terminal and is firmly fastened by screws.

Preferably, the protection device operates normally: in the first terminal row 1, the No. 1, 3, 5 and 7 terminal metal pieces 34 slide to the communication position of the fixed conductors 35 on the two sides; 2. the No. 4, 6 and 8 terminal metal pieces 34 slide to the position where the fixed conductors 35 on the two sides are not communicated; in the second terminal row 2, the A, B, C, D-size terminal fitting 34 is slid to the position where the fixed conductors 35 on both sides are not connected; thereby make 2, 4, 6, No. 8 terminal right side fixed conductor 35 to terminal row 2A, B, C, D terminal left side fixed conductor 35 and CT cable 6 all not electrified, form two breaks and prevent mistake, reduce the mistake and bump electrified CT test terminal 3's risk, guarantee current transformer secondary circuit does not open a way, and then guarantee protection device steady operation.

Preferably, when the protection device verifies:

in the first step, in the second terminal row 2, the A, B, C, D terminal metal piece 34 slides to the position where the fixed conductors 35 on both sides are communicated, and the resistance between the test jacks 33 on the right sides of the 2, 4, 6 and 8 terminals is measured to be about 0 Ω, which indicates that the short circuit is reliable.

In the second step, in the first terminal row 1, the terminal metal pieces 34 No. 2, 4, 6 and 8 slide to the position where the fixed conductors 35 on both sides are communicated, and the current channel of the protection device 7 is changed from current flowing to no current flowing at this time, which indicates that the short circuit is reliable.

And thirdly, in the first terminal row 1, the No. 1, 3, 5 and 7 terminal metal pieces 34 slide to the position where the fixed conductors 35 on the two sides are not communicated, so that the protection device 7 is completely isolated from the electrified secondary circuit, and the electrified sealing-in of the secondary circuit of the current transformer is safely and conveniently realized.

The above-described embodiments are merely preferred embodiments of the present invention, and should not be construed as limiting the present invention, and features in the embodiments and examples in the present application may be arbitrarily combined with each other without conflict. The protection scope of the present invention is defined by the claims, and includes equivalents of technical features of the claims. I.e., equivalent alterations and modifications within the scope hereof, are also intended to be within the scope of the utility model.

Claims

1. The utility model provides a current transformer secondary circuit live sealing device which characterized by: the testing device comprises a first terminal row (1), a second terminal row (2), a CT testing terminal (3), two-connection short connecting pieces (4) and four-connection short connecting pieces (5); the first terminal row (1) is provided with eight CT test terminals (3) which are mutually arranged, and every two CT test terminals are in a group and are connected with four two short connecting tabs (4) to form four test terminal groups; four CT test terminals (3) which are mutually arranged are arranged on the second terminal row (2), and the four short connecting pieces (5) are connected with the four CT test terminals (3); the CT cable (6) is electrically connected with the CT test terminals (3) on the first terminal row (1) and the second terminal row (2).

2. The live-wire sealing device for the secondary circuit of the current transformer as claimed in claim 1, wherein: the wire inlet side and the wire outlet side of the CT test terminal (3) are provided with wiring holes (31), two ends of the upper side are provided with wiring screws (32) and test jacks (33) respectively, the middle part of the upper side is provided with a metal piece (34), and two sides of the metal piece (34) are provided with fixed conductors (35).

3. The live-wire sealing device for the secondary circuit of the current transformer as claimed in claim 2, wherein: the metal piece (34) is in lateral sliding conduction with the fixed conductor (35).

4. The live-wire sealing device for the secondary circuit of the current transformer as claimed in claim 1, wherein: four outgoing line sides of the four test terminal groups are connected with incoming line sides of the four CT test terminals (3) on the second terminal row (2) through four CT cables (6), and cables led out from the other four outgoing line sides of the four test terminal groups are connected with a protection device (7).