CN202159571U

CN202159571U - Current transformer

Info

Publication number: CN202159571U
Application number: CN2011202548012U
Authority: CN
Inventors: 贾延超; 廖汉; 徐姗; 杨怀亮
Original assignee: SHENYANG HUALI ENERGY EQUIPMENT MANUFACTURING Co Ltd
Current assignee: SHENYANG HUALI ENERGY EQUIPMENT MANUFACTURING Co Ltd
Priority date: 2011-07-19
Filing date: 2011-07-19
Publication date: 2012-03-07
Anticipated expiration: 2021-07-19

Abstract

The utility model provides a current transformer, which solves the problems that the conventional current transformer of C-GIS products arranged on the outside of a gas box is difficult in on-situ construction and high in manufacturing cost. The current transformer is characterized in that the epoxy resin housing of the current transformer is equipped with a flange and a boss. The part of the epoxy resin housing in contact with a primary conductive body is equipped with an inwardly recessed annular groove. A concentric cylindrical structure is formed by the primary conductive body and grounding electric field shield covers arranged between secondary coils and the primary conductive body inside the epoxy resin housing. Due to the adoption of the current transformer, the phenomenon of the concentrated field intensity at the interfaces of the three substances of epoxy resin, a metal conductor and sulfur hexafluoride gas is prevented, so that the problems of partial discharge and failed insulation caused by the high field intensity are avoided. Meanwhile, the insulation performances among epoxy resin, the metal conductor and sulfur hexafluoride gas, and the insulation performances of the three substances relative to the ground are improved. Therefore, the current transformer can be used in Sulfur Hexafluoride (SF6) gas insulation environment with the air pressure thereof to be 0.1-0.2 Mpa and reduces the manufacture cost. Meanwhile, the factory assembling of the current transformer is realized and the on-site installation work is also simplified.

Description

A kind of current transformer

Technical field

The utility model belongs to high voltage electrical apparatus technical field, particularly a kind ofly is used to charge into 0.1～0.2MPaCurrent transformer in the inflation cabinet of air pressure sulfur hexafluoride gas.

Background technology

Characteristics of C-GIS (cabinet type gas-insulated metal-enclosed switchgear) product are that the inner the blowing pressure of gas tank is lower, if current transformer is installed in the gas tank, external insulation and phase insulation are difficult to guarantee; Cause alternate easily or primary connection and secondary coil turn-to-turn insulation failure, especially voltage levels (72.5kV and above electric pressure) especially like this, therefore; The current transformer of the C-GIS product of prior art generally adopts the low-pressure type current transformer, is positioned at the gas tank outside, directly is sleeved on cable; Because the general secondary coil more (being generally 4 ~ 5) that requires on the engineering, output capacity is bigger, and the overall dimension of current transformer receives the restriction of mould again; Usually need a current transformer be divided into 2 ~ 3; Current transformer provides the secondary output capacity to be generally less than 10VA, during on-the-spot the installation, must earlier these current transformers be enclosed within on the cable; Carry out the making and the installation of cable termination again; Very inconvenient, user's site operation difficulty is bigger, and cost of manufacture is higher.

Summary of the invention

The utility model technical problem to be solved is, overcomes prior art and has weak point, and providing a kind of can guarantee 0.1～0.2MPaSatisfy the current transformer that dielectric strength requires under the air pressure conditions, realize that current transformer assembles at equipment manufacturing, do not influence the making and the installation at on-site cable terminal simultaneously again, reduce the difficulty of user's site operation.

The technical scheme that the utility model is taked comprises epoxy package, secondary leading-out terminal, secondary coil, primary conductive body and ground shield; Earth shield covers on the external side of primary conductive; Secondary coil is in the ground shield outside; Said epoxy package external shape is designed to cylindrical, and epoxy package is provided with flange and boss, and the contact site with the primary conductive body on epoxy package is provided with to the slightly recessed cannelure in inside.

The ground connection electric field shielding cover that between the inner secondary coil of said epoxy package and primary conductive body, is provided with becomes the concentric column structure with the primary conductive body.

Compared with prior art; The beneficial effect of the utility model is; Through the current transformer contour structures optimized with solve the measure that epoxy resin, metallic conductor and sulfur hexafluoride gas three material interface field intensity are concentrated, avoided the partial discharge and insulation failure problem that cause by high electric field strength, improved current transformer alternate and relatively between insulating capacity; Therefore, the current transformer of the utility model can use 0.1～0.2MPaIn the SF6 of air pressure (sulphur hexafluoride) the gas-insulated environment; Replaced being installed in the gas tank outer cover and be connected on the low-pressure type current transformer on the cable one time, not only increased single the secondary coil quantity that current transformer is interior, the secondary output capacity also is greatly improved; The quantity and the mould input of current transformer have been reduced; Reduce manufacturing cost, realized current transformer batch production assembling, also simplified on-site installation work.

The beneficial effect of the utility model also is the flange shape that the epoxy package two ends are provided with; The insulation of the primary conductive body in the middle of having strengthened; And pass through at epoxy package set inside ground connection electric field shielding cover; Improved the dielectric strength between primary winding and secondary coil, made the current transformer safety and reliability.

Description of drawings

Fig. 1 is the front view of the utility model,

Fig. 2 is the vertical view of Fig. 1,

Fig. 3 is the A-A cutaway view of Fig. 2,

Fig. 4 is the B portion enlarged drawing (ring channel structures sketch map) of Fig. 3.

Among the figure:

1. epoxy package,

1-1. flange, 1-2. cannelure, 1-3. boss

2 secondary leading-out terminals,

3. secondary coil,

4. primary conductive body,

5. ground shield,

6. punching bus.

Embodiment

The embodiment of the utility model is provided below in conjunction with accompanying drawing.

Shown in accompanying drawing, the utility model comprises epoxy package 1, secondary leading-out terminal 2, secondary coil 3, primary conductive body 4 and ground shield 5 and punching bus 6, wherein; Punching bus 6 is positioned at the position of lateral shaft center line; Ground shield 5 is in primary conductive body 4 outsides, and secondary coil 3 is in ground shield 5 outsides, and said punching bus 6, ground shield 5, primary conductive body 4 and secondary coil 3 are all located in mould; And adopt epoxide resin vacuum to pour into a mould; Epoxy package 1 external shape is designed to cylindrical, and epoxy package 1 is provided with flange 1-1 and boss 1-3, and the contact site with primary conductive body 4 on epoxy package 1 is provided with to the slightly recessed cannelure 1-2 in inside; Therefore and changed the direction of current transformer two ends power lines; Reduced the electric field strength of epoxy resin, metallic conductor and sulfur hexafluoride gas three material interfaces, avoided the partial discharge that causes by high electric field strength and the failure problem that insulate, the utility model current transformer has been applicable to charges into 0.1～0.2MPaThe operational environment of low pressure sulfur hexafluoride gas; Said secondary coil 3 can be installed 1～5 according to actual needs; This structure can be avoided secondary coil 3 to receive the electric field effects of primary conductive body 4 and produce turn-to-turn short circuit, is fixed with secondary leading-out terminal 2 on the top of secondary coil 3.

4 one-tenth concentric column structures of ground connection electric field shielding cover 5 and primary conductive body of setting between the inner secondary coil 3 of epoxy package 1 and primary conductive body 4; The electric field that fabulous even epoxy package 1 is inner; Avoided simultaneously the Insulation Problems between inner primary conductive body 4 of same current transformer and the secondary coil 3 again fully; Under the constant situation of current transformer overall dimension; Can increase and decrease the quantity of secondary coil 3 according to actual needs; And the secondary output capacity of every secondary coil is not less than 15VA, and the secondary lead-out wire of current transformer is drawn through the perforate of boss 1-3 on the gas tank shell that is positioned at the instrument transformer middle part, and the two matching part seals with round section joint ring.

Claims

1. current transformer; Comprise epoxy package (1), secondary leading-out terminal (2), secondary coil (3), primary conductive body (4) and ground shield (5); It is characterized in that; Ground shield (5) is in primary conductive body (4) outside, and secondary coil (3) is in ground shield (5) outside, and said epoxy package (1) external shape is designed to cylindrical; Epoxy package (1) is provided with flange (1-1) and boss (1-3), and contact site last at epoxy package (1) and primary conductive body (4) is provided with to the slightly recessed cannelure in inside (1-2).

2. according to the said a kind of current transformer of claim 1; It is characterized in that the ground connection electric field shielding cover (5) of setting becomes the concentric column structure with primary conductive body (4) between the inner secondary coil (3) of said epoxy package (1) and primary conductive body (4).