CN215770824U

CN215770824U - Current transformer of high-voltage primary electric insulation structure

Info

Publication number: CN215770824U
Application number: CN202122254939.9U
Authority: CN
Inventors: 李淑兰; 孙瑛; 何艳坤; 李娜; 王展; 许堂; 姜冬雪
Original assignee: DALIAN NO1 INSTRUMENT TRANSFORMER CO LTD
Current assignee: DALIAN NO1 INSTRUMENT TRANSFORMER CO LTD
Priority date: 2021-09-17
Filing date: 2021-09-17
Publication date: 2022-02-08
Anticipated expiration: 2031-09-17

Abstract

The utility model relates to a current transformer with a high-voltage primary electric insulation structure, which mainly comprises an inner iron core, a first insulating coil, a second insulating coil and an outer insulating body, and is characterized in that insulating baffles are arranged at the edges of two opposite sides of the top of the outer insulating body of the current transformer, a primary wiring terminal is positioned between the two insulating baffles, after the primary wiring terminal is connected with a primary conductor, the vertical distance B from the upper plane of the primary conductor to the horizontal extension line of the top end of the insulating baffle is equal to or slightly larger than the vertical distance A from the outer side edge of the primary wiring terminal to the outer edge of the outer insulating body on the same side, and a creepage umbrella skirt is arranged outside the outer insulating body below the primary wiring terminal. The method is characterized in that: the creepage distance between the phase to the ground and the phase is increased, the high insulation and voltage resistance can be met, the product size is small, the manufacturing cost is low, and the creepage distance reducing device is applied to a switch cabinet or a transformer substation (a switch station), can reduce the installation clearance between three-phase current transformers, reduces the installation space and reduces the construction cost of the switch cabinet or the transformer substation (the switch station).

Description

Current transformer of high-voltage primary electric insulation structure

Technical Field

The utility model relates to a current transformer, in particular to a current transformer with a high-voltage primary electric insulation structure used in a switch cabinet.

Background

In an electric power system, a current transformer applied to the conditions of high altitude, high pollution and high humidity needs to have high insulation and voltage resistance, namely, the requirement on the insulation and voltage resistance level between the relative ground and the relative phase of the current transformer is high, so that the operation requirement is met. At present, the solution for improving the electrical insulation performance of the current transformer is to increase the overall size of the current transformer, increase the distance between the current transformers installed in a switch cabinet side by side, increase the size and installation distance of the current transformer, and change the corresponding overall space size of the switch cabinet and the overall building space of the whole transformer substation (switch station), thereby improving the product cost and the engineering cost of the current transformer, the switch cabinet and the transformer substation (switch station).

Disclosure of Invention

The utility model aims to provide a current transformer with a high-voltage primary electric insulation structure, which has small volume, small installation gap and high insulation and voltage resistance level.

The technical solution of the utility model is as follows: a current transformer of a high-voltage primary electric insulation structure is mainly composed of an inner iron core, a first insulating baffle, a secondary coil and an outer insulator, and is characterized in that insulating baffles are arranged at the edges of two opposite sides of the top of the outer insulator of the current transformer, a primary wiring terminal is positioned between the two insulating baffles, after the primary wiring terminal is connected with a primary conductor, the vertical distance B from the upper plane of the primary conductor to the horizontal extension line of the top end of the insulating baffle is equal to the vertical distance A from the outer side edge of the primary wiring terminal to the outer edge of the outer insulator at the same side or the distance B is slightly larger than A, and a creepage umbrella skirt is arranged outside the outer insulator below the primary wiring terminal.

The primary connecting terminal is higher than the surface of the outer insulator, and the size of the higher part is the same as the thickness of the insulating sleeve sleeved on the primary conductor.

The vertical distance B from the upper plane of the primary conductor to the horizontal extension line of the top end of the insulating baffle is greater than or equal to 80 mm.

The insulating baffle is arranged along the length direction of the outer insulator of the current transformer.

The utility model provides a current transformer with a high-voltage primary electric insulation structure, which adopts the following steps: 1. two opposite sides of the top of an insulator outside the current transformer are provided with insulating baffles, and a primary wiring terminal is positioned between the two insulating baffles; 2. a creepage shed is arranged outside the outer insulator below the primary wiring terminal; 3. the vertical distance from the upper plane of the primary conductor to the horizontal extension line of the top end of the insulating baffle is set to be larger than or approximately equal to the vertical distance from the outer side edge of the primary wiring terminal to the outer side edge of the outer insulator on the same side, and the like, so that the insulating and voltage-resisting performance of the current transformer is improved.

The utility model is characterized in that: the creepage distance between the relative ground and the phases is increased, the current transformer has high insulation and voltage resistance, the product volume is small, the manufacturing cost is low, the mounting clearance between the three-phase current transformers can be reduced when the current transformer is applied to a switch cabinet or a transformer substation (a switch station), the required mounting space is small, and the construction cost of the switch cabinet or the transformer substation (the switch station) is reduced.

Drawings

FIG. 1 is an external structural view of the present invention;

FIG. 2 is a side view of FIG. 1;

FIG. 3 is a top view of FIG. 1;

fig. 4 is a schematic view of the installation of the three-phase current transformer of the present invention.

Detailed Description

The utility model is described in further detail below with reference to the accompanying drawings:

as shown in fig. 1, 2 and 3, the current transformer provided in this embodiment is mainly composed of an internal iron core, a primary coil, a secondary coil and an external insulator 1 molded by casting epoxy resin, and the structure of this part is the same as that of the prior art and is not described again. Different from the prior art, the edges of two opposite sides of the top of the outer insulator along the length direction are respectively provided with an insulating baffle 3, and the length of the insulating baffle can be the same as that of the edge of the outer insulator of the current transformer, and can also be slightly longer or shorter. The insulating baffle plate can be integrated with the epoxy resin outer insulator, namely, the insulating baffle plate is molded by one-time casting, or the insulating baffle plate can be fixedly installed on the outer insulator. The arrangement of the insulating baffle plates can improve the primary phase insulation and voltage resistance of the current transformer, simultaneously can also reduce the height of the current transformer, reduce the manufacturing cost, save the installation space, reduce the installation gap between three-phase current transformers in application, see fig. 4, occupy small space and save the construction cost of a switch cabinet or a transformer substation (a switch station). The primary wiring terminal 2 is positioned between the two insulating baffles, the inlet and outlet primary wiring terminals are arranged in the middle as much as possible, and meanwhile, the vertical distance A from the outer side edge of the inlet and outlet primary wiring terminals to the outer edge of the outer insulator on the same side is equal to the vertical distance B from the upper plane of the primary conductor installed on the primary wiring terminal to the horizontal extension line of the top end of the insulating baffle, or the distance B is slightly larger than A. The vertical distance B from the upper plane of the primary conductor to the horizontal extension line of the top end of the insulating baffle is equal to or greater than 80mm, and both the distance B and the distance A are 80mm in the embodiment. The equidistant relation between the distance A and the distance B can ensure that the creepage distances between the primary wiring terminal pair and the ground are consistent in the height and length directions and have the same insulating property. The primary connecting terminal is slightly higher than the surface of the outer insulator, and the size of the part higher than the primary connecting terminal is equal to the thickness of the insulating sleeve 6 sleeved on the primary conductor, generally more than 3.5mm, so as to ensure that the primary conductor 5 sleeved with the insulating sleeve is reliably electrically connected with the primary connecting terminal, i.e. the end part of the insulating sleeve on the primary conductor is leaned against the side surface of the primary connecting terminal. A creepage shed 4 is arranged outside the outer insulator below the primary wiring terminal and is made of insulating materials such as resin and the like, so that the insulation and voltage resistance of primary high voltage to the ground are further improved.

Claims

1. A current transformer of a high-voltage primary electric insulation structure is mainly composed of an inner iron core, a first insulating baffle, a secondary coil and an outer insulator, and is characterized in that insulating baffles are arranged at the edges of two opposite sides of the top of the outer insulator of the current transformer, a primary wiring terminal is positioned between the two insulating baffles, after the primary wiring terminal is connected with a primary conductor, the vertical distance B from the upper plane of the primary conductor to the horizontal extension line of the top end of the insulating baffle is equal to the vertical distance A from the outer side edge of the primary wiring terminal to the outer edge of the outer insulator at the same side or the distance B is slightly larger than A, and a creepage umbrella skirt is arranged outside the outer insulator below the primary wiring terminal.

2. A current transformer of a primary high voltage electrical insulation structure according to claim 1, wherein the primary connection terminal is higher than the surface of the outer insulator, and the raised portion has a size equal to the thickness of the insulating sheath fitted over the primary conductor.

3. A current transformer of a high voltage primary electrical insulation structure according to claim 1, wherein a vertical distance B from an upper plane of the primary conductor to a horizontal extension line of a top end of the insulating barrier is greater than or equal to 80 mm.

4. The current transformer of claim 1, wherein the insulating barrier is disposed along a length of an outer insulator of the current transformer.