CN2643459Y

CN2643459Y - Combined high-voltage current transformer

Info

Publication number: CN2643459Y
Application number: CN 03276838
Authority: CN
Inventors: 黄维枢
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-07-15
Filing date: 2003-07-15
Publication date: 2004-09-22
Anticipated expiration: 2013-07-15

Abstract

A combined high-voltage current transformer comprises an independent high-voltage current transformer, a capacity-typed high-voltage bushing and a low voltage pulling-through current transformer. The low voltage pulling-through current transformer is fixedly assembled outside an earthing panel of the capacity-typed high-voltage bushing, forming a combination of the capacity-typed high-voltage bushing and the low voltage pulling-through current transformer, and the combination is fixed at the top of the independent high-voltage current transformer. The lead wire of an end screen of the high-voltage bushing is electrically connected with the box body of the pulling-through current transformer and one terminal of a coil thereof, and two terminals of the coil of the pulling-through current transformer are respectively and electrically connected with two terminals of a primary turn of the independent high-voltage current transformer. A transformation ratio K1 of the pulling-through current transformer multiplies a transformation ratio K2 of the independent high-voltage current transformer and equals to a transformation ratio K of the combined high-voltage current transformer. The utility model has the advantages of reducing amount of the insulating material, saving the time of winding the insulating material and the even distribution of the voltage.

Description

The combined high-tension current instrument transformer

Technical field:

The utility model relates to a kind of combined high-tension current instrument transformer, is used to measure electric current and relaying protection, is usually used in 220kV and above electric pressure.

Background technology:

At present, the current transformer of each electric pressure is the single stage type current transformer both at home and abroad, and great majority are electric capacity filling type, gas-filled type or poured with epoxy resin formula current transformer.The ZL99201400.X utility model patent of State Intellectual Property Office's Granted publication on February 2nd, 2000, the New Dry Type High Tension Current Transformer that a kind of inventor proposes is disclosed, have ne-leakage, no pollution flashover, fire prevention, explosion-proof, volume is little, advantage such as in light weight, easy to maintenance.But the sort of current transformer no matter, along with electric pressure raises, a lot of problems appear in the capital: usually, grade of the every rising of electric pressure, insulating material will increase a lot, by square increase of electric pressure ratio, for example the use amount of the current transformer insulating material of 220kV is more than 4 times of 110kV; Make the dry-type current transformer of a 220kV, than the dry-type current transformer of making 110kV, much more difficult, the time that holds insulating barrier and capacitance plate exceeds more than 4 times, and product percent of pass also decreases; In addition, the height of product is relevant with electric pressure, and the air gap and the electric pressure of its external insulation are approximated to direct ratio, for example, the current transformer height of 110kV is 2m, and the current transformer height of 220kV is that 3m is many, and weight approximates 3 times of 110kV, causes difficulty for the transportation of product.

For solving the problems of the technologies described above, once the someone proposed the scheme with cascade-type current transformer.This cascade-type current transformer adopts chain insulation system: secondary winding surrounds on the ring-shaped core, and winding wire turn is the coiled ring-type also, after interosculating as chain link and secondary winding, holds the cable paper tape continuously respectively on winding and secondary winding.Its technology that holds insulation is very complicated, can only adopt manual holding, occur insulation defect unavoidably, especially the insulation on three tie-points can not resemble the basic insulation tight, become the weak link of insulation system, take place to discharge or puncture at this place easily when test or operation; Because the volution body section out-of-shape of two intersections, the electric field that calculates the chain insulation has certain difficulty, may cause electric field strength inhomogeneous, and local field strength is too high, makes product damage in service or causes design margin excessive, and cost is increased; Because all unshakable in one's determination and winding all is contained in the insulator, its size and weight are bigger, and when superhigh pressure, this shortcoming is obvious especially; Because the winding and the electric capacity between the secondary winding of chain insulation system are less, its stray capacitance over the ground is relatively large, so the voltage skewness of two current transformers, and the higher level is about 55% of whole voltages, subordinate is 45%, and insulation can not be made full use of.Therefore, above-mentioned cascade-type current transformer is not seen the formation commercial product.

The utility model content:

The purpose of this utility model is intended to overcome the deficiency of above-mentioned prior art, a kind of combined high-tension current instrument transformer is provided, the assembly and one of making a capacitor type bushing and a low pressure penetration type current transformer in advance is high-tension current inductor independently, after the site installation, just can form the current transformer of a voltage levels easily.

According to combined high-tension current instrument transformer of the present utility model, comprise that one is positioned at the independently high-tension current inductor of bottom, a superposed capacitor type bushing and a low pressure penetration type current transformer, described low pressure penetration type current transformer firmly is assembled in outside the ground connection screen of capacitor type bushing, constitute the assembly of a capacitor type bushing and low pressure penetration type current transformer, this assembly is fixed on the top of described independently high-tension current inductor, described capacitor type bushing is in the shape of the letter V, in-line or U font, its end screen lead-in wire is electrically connected with the casing of low pressure penetration type current transformer and a terminal of coil thereof, and the two-terminal of the coil of low pressure penetration type current transformer is electrically connected with the two-terminal of a winding of high-tension current inductor independently respectively.

The no-load voltage ratio K1 of its mesolow penetration type current transformer and the product of the no-load voltage ratio K2 of high-tension current inductor independently equal the no-load voltage ratio K of this combined high-tension current instrument transformer.

The combined high-tension current instrument transformer that the utility model provides has following advantage: reducing the insulating material consumption, is example with the 220kV current transformer, and the insulating material consumption can reduce, and is 2 times of 110kV current transformer consumption basically; The time that existing 220kV dry-type current transformer holds insulating material is about 5 days, and according to the 220kV combined high-tension current instrument transformer that the utility model provides, the time that holds insulating material only needs 2 days, and total cost reduces about 1/3; Can full mechanization production, product percent of pass improves greatly, thereby improves the quality of products, operational reliability and lsafety level; Convenient transportation can transport by separate unit, and except that reducing greatly the height, weight also alleviates greatly, is about 1/3 of single-stage current transformer; During site installation, only need tighten a small amount of auxiliary assembly processes such as several bolts, can finish assembling; Owing to be the capacitor type insulating structure, so between bushing and the low pressure penetration type current transformer, independently the winding and the capacitance between the secondary winding of high-tension current inductor are bigger, stray capacitance influences is less, voltage is evenly distributed, and the assembly of bushing and low pressure penetration type current transformer and the voltage of independently sharing on the high-tension current inductor are 1/2 of output voltage.

Description of drawings:

Fig. 1 is the front view of first kind of embodiment of combined high-tension current instrument transformer of the present utility model;

Fig. 2 is the front view of second kind of embodiment of combined high-tension current instrument transformer of the present utility model;

Fig. 3 is the front view of the third embodiment of combined high-tension current instrument transformer of the present utility model;

Fig. 4 is for being the front view of the 4th kind of embodiment of combined high-tension current instrument transformer of the present utility model.

Embodiment:

Referring to Fig. 1, first of combined high-tension current instrument transformer of the present utility model kind of embodiment shown in it.Comprise a superposed capacitor type bushing 2 and be positioned at the middle part a low pressure penetration type current transformer 3 assembly and be positioned at a high-tension current inductor 1 independently of bottom.

Described independently high-tension current inductor 1 is a Dry Type High Tension Current Transformer, and one time winding adopts the capacitor type insulating structure, has the multiturn coil that is formed by lead coiling insulated from each other.Its secondary winding is according to user's needs setting.Wherein the part of a winding protuberate basic unit 11 forms vertically upwardly extending both arms.

Described capacitor type bushing 2 becomes the V font substantially, and the one end terminal can be connected with for example transformer station's isolation switch, and other end wire clamp can be connected with the switchgear of for example transformer station.Described capacitor type bushing 2 is composite organic insulation sleeve pipes of capacitor screen, from inside to outside successively by conducting rod or contact tube or lead, rigid backbone, forms (its concrete structure does not illustrate among the figure one by one owing to have nothing to do with the utility model) with oversheath, silicon rubber full skirt and the end screen capacitance plate lead-in wire of a plurality of insulators of all pressing screen, insulation filling agent, organic insulation.Wherein the silicon rubber full skirt can be bonded in the surface of capacitor type bushing 2 oversheaths or the integral molded plastic surface at the capacitor type bushing.

Described low pressure penetration type current transformer 3 firmly is assembled in outside the ground connection screen at capacitor type bushing 2 middle parts, thereby constitute the assembly of a capacitor type bushing 2 and low pressure penetration type current transformer 3, this assembly is fixed on the independently top of high-tension current inductor 1.More particularly, can by be arranged on this assembly bottom and independently one between the top of high-tension current inductor 1 cross line bridge 7, by the securing member (not shown) of bolt and so on, this assembly is fixed on two grading shields 12 at high-tension current inductor 1 top independently.Described cross is provided with the passage 71 that guides a winding (not shown) of high-tension current inductor 1 independently to pass in the line bridge 7.As a kind of alternative, the above-mentioned line bridge of crossing also can be configured as one with the casing 33 of low pressure penetration type current transformer 3

Described capacitor type bushing end screen capacitance plate lead-in wire 4 is electrically connected with the casing 33 of described low pressure penetration type current transformer 3 and a terminal 31 of coil 5 thereof, and the two-

terminal

31 and 32 of the coil of described low pressure penetration type current transformer 3 is electrically connected with the two-terminal (not shown) of a winding of described independently high-tension current inductor 1 respectively.The no-load voltage ratio K1 of low pressure penetration type current transformer 3 and the product of the no-load voltage ratio K2 of high-tension current inductor 1 independently equal the no-load voltage ratio K of this combined high-tension current instrument transformer.With a 220kV, 2000/1 current transformer is an example, and the no-load voltage ratio K1 of low pressure penetration type current transformer 3 is 2000/5, and independently the no-load voltage ratio K2 of high-tension current inductor 1 is 5/1, and total no-load voltage ratio K is 2000/1.

Referring to Fig. 2, second of combined high-tension current instrument transformer of the present utility model kind of embodiment shown in it.Only be that with first kind of embodiment difference described capacitor type bushing 2 is in-line.

Referring to Fig. 3, the third embodiment of combined high-tension current instrument transformer of the present utility model shown in it.Different with above-mentioned two kinds of embodiment is that described capacitor type bushing 2 is the U font, and the connecting plate 6 with certain dielectric strength and sufficient mechanical strength is set between the sleeve pipe two ends.

At described independently high-tension current inductor 1 is under the situation of dry-type current transformer, can also adopt epoxy resin integral cast-type insulation system, owing to have higher strength and stiffness, thereby be particularly suitable for combined high-tension current instrument transformer of the present utility model.

Referring to Fig. 4, the 4th kind of embodiment of combined high-tension current instrument transformer of the present utility model shown in it.Different with first kind of embodiment is that described independently high-tension current inductor 1 adopts conventional oil-filled type current transformer.

It is pointed out that the foregoing description only is explanation and understands the utility model, and be not to be qualification of the present utility model.Protection range of the present utility model should be determined by the technical scheme of each claim.

Claims

1, the combined high-tension current instrument transformer, comprise that one is positioned at the independently high-tension current inductor (1) of bottom, an one superposed capacitor type bushing (2) and a low pressure penetration type current transformer (3), it is characterized in that: described low pressure penetration type current transformer (3) firmly is assembled in outside the ground connection screen of capacitor type bushing (2), constitute the assembly of a capacitor type bushing (2) and low pressure penetration type current transformer (3), this assembly is fixed on the top of described independently high-tension current inductor (1), described capacitor type bushing (2) is in the shape of the letter V, in-line or U font, its end screen lead-in wire (4) is electrically connected with the casing of low pressure penetration type current transformer (3) and a terminal (31) of coil (5) thereof, and the two-terminal (31) of the coil of low pressure penetration type current transformer (3) and (32) are electrically connected with the two-terminal of a winding of high-tension current inductor (1) independently respectively.

2, according to the described combined high-tension current instrument transformer of claim 1, it is characterized in that: the top of described independently high-tension current inductor (1) is provided with two grading shields (12), described assembly is crossed line bridge (7) by one and is fixed on described two grading shields (12), describedly crosses the passage (71) that a winding being provided with the described independently high-tension current inductor of guiding (1) in the line bridge (7) passes.

3, according to the described combined high-tension current instrument transformer of claim 1, it is characterized in that: a winding of described independently high-tension current inductor (1) is a multiturn coil, is formed by lead coiling insulated from each other.

4, according to the described combined high-tension current instrument transformer of claim 1, it is characterized in that: described capacitor type bushing (2) is the U font, and the connecting plate (6) with certain dielectric strength and sufficient mechanical strength is set between the sleeve pipe two ends.

5, according to the described combined high-tension current instrument transformer of claim 1, it is characterized in that: described capacitor type bushing (2) is the composite organic insulation sleeve pipe of capacitor screen, all presses insulator, the insulation filling agent of screen, oversheath, silicon rubber full skirt and the described end screen lead-in wire of organic insulation to form by conducting rod or contact tube or lead, rigid backbone, band successively from inside to outside.

6, according to the described combined high-tension current instrument transformer of claim 5, it is characterized in that: described silicon rubber full skirt is bonded in the surface of capacitor type bushing (2) oversheath or the integral molded plastic surface at the capacitor type bushing.

7, according to the described combined high-tension current instrument transformer of claim 1, it is characterized in that: described independently high-tension current inductor (1) is oil-filled type or dry-type current transformer, and one time winding adopts the capacitor type insulating structure.

8, according to the described combined high-tension current instrument transformer of claim 1, it is characterized in that: described independently high-tension current inductor (1) adopts epoxy resin integral cast-type insulation system.