CN86204593U

CN86204593U - Core-separated current-transformer with bucking coil

Info

Publication number: CN86204593U
Application number: CN 86204593
Authority: CN
Inventors: 岑云操; 潘守礼
Original assignee: KUNMING MOTOR TOOL FACTORY
Current assignee: KUNMING MOTOR TOOL FACTORY
Priority date: 1986-07-09
Filing date: 1986-07-09
Publication date: 1987-08-19

Abstract

The utility model provides a current transformer, which can make the iron core be separated by variant material; can make one part of twice coil wrap around one part of the separated iron core to form fractional number turns compensation; can adopt the method that an upper iron core column and a lower iron corn column are additionally provided with short-circuited turns so as to further compensating error. The current transformer for iron core column is made of silicon steel sheet; the upper iron core column and the lower iron core column are sheathed with the current transformer of coils so as to improve accuracy of measurement; the utility model is adapted for production or the utility model is adapted for making old type products change into high-level products.

Description

Core-separated current-transformer with bucking coil

The utility model relates to a kind of improved current transformer, for iron core column is to be changed by silicon steel sheet, the upper core column sleeve is coil (1) and secondary coil some (12) once, the lower core column sleeve has the current transformer of another part (3) of secondary coil, can produce or be transformed into the current transformer of high measurement accuracy grade, improve the accuracy of electric current metering.

All numberings herein, all referring to the embodiment accompanying drawing (Fig. 1, Fig. 2, Fig. 3).

Existing this type of electrical current transformer mainly adopts three kinds of compensation methodes to improve accuracy of measurement: magnetic shunt (5), upper core post (7) add the method for short circuit circle (6) and secondary coil (3,12) minimizing one circle.But only depend on the current transformer accuracy of above three kinds of methods compensation not high, be generally 0.5 grade, at present domestic a large amount of this class current transformers that using.

Task of the present utility model is according to the do not worry requirement of the replacement to be upgraded of electric energy metrical level in the national Ministry of Water Resources and Electric Power " electrical measuring instrument device vertification regulation ", has proposed the problem of research " improving the current transformer accuracy ".

Task of the present utility model is that following mode is finished:

(1). with iron core column (2,7) in certain separation ratio separately, the separation ratio can be between 1/44 to 43/44, circumjacent this long-pending long-pending ratio of whole core section that accounts for of core section partly of the fractional turns (17) that its expression secondary coil (3,12) compensating error is used.Separate with permeability and this iron core material (10) inequality in the middle of the iron core, the thickness that separates material is 0.01mm to 10mm, these materials can be permeability permeability magnetic materials inequality such as steel alloy, other ferromagnetic material, also can be as nonmetallic materials such as paper, air, timber, plastics, electrical insulating materials, can also be the metal material as non-magnetic conductions such as copper, aluminium.Certain a part of sectional area of iron core column is separated out by a fractional value between 1/44 to 43/44, when the coiling secondary coil, allow a circle or a few circle round this part iron core (8), (9) ((11), (13), promptly, make secondary coil have a circle or a few circle to walk around the arbitrary part of the iron core that is spaced or walk around and to form these various fractional turns combinations partly that compensating error is used around the sectional area of this part iron core.Thereby around the comparing of whole iron core column sectional area, be the some fractional values between 1/44 to 43/44 in the variation that makes this circle of secondary coil or flux change in a few circle coil and number of ampere turns and the prior art.This just dwindles into this fractional value with the compensating error of original current transformer, and this has just obtained the required numerical value of compensation more accurately that reaches of the measure error of high level current transformer.

(2). on lower core post (2), also adopt short circuit circle (4), the resistance value of short circuit circle is adjusted between 0.006 ohm to 0.0206 ohm, thereby change the size of short circuit current, phase difference is compensated, can also make simultaneously the ratio value obtain compensation, the accuracy of measurement of current transformer is further improved like this.More than two measures, be to adopt separately wherein a kind of or adopt two kinds of effects that all have the accuracy of measurement of significantly improving simultaneously, be good to adopt two kinds of compensation effects simultaneously especially, these three kinds of schemes all are suitable for low-voltage current mutual inductor and high-tension current inductor.

The utility model not only can be used for producing, and also can be used for old model and be transformed into high level current transformer.The external form basis of original product and the characteristic of good stability have not only been kept for new production or the current transformer that is transformed into, and the user needn't change low pressure measurement facility switching plate, manufacturer needn't change production equipment, frock clamp, also avoided metering upgrading simultaneously, updated and the scrapping and waste of this class current transformer that is now using just in a large number that will cause.And, no matter produce or be transformed into high level current transformer, its cost is significantly less than the other products of same level.

Below with reference to accompanying drawing the utility model is described in further detail.

Fig. 1 is the front view of a kind of concrete structure of the utility model.

Fig. 2 be among Fig. 1 along A-A to cross sectional plan view.

Fig. 3 is an electrical schematic diagram of the present utility model.

With reference to Fig. 1, Fig. 2, Fig. 3, get 0.5 grade of current transformer of a LQG-0.5 type and be the basis, add short circuit circle (4) compensation at lower core post (2) separately then, or adopt iron core cellular-type fractional turns (17) compensation separately, and perhaps not only adopt the lower core post to add the short circuit circle but also adopt iron core cellular-type fractional turns (17) compensation, can directly find out the effect of compensation at last according to test result.Testing standard is a JJG313-83 Chinese people republic metering appliance detecting rules " Verification of Measuring Current Transformer " altogether.

0.5 grade of current transformer test result of a LQG-0.5 type is as follows:

Table 1

This moment is with iron core (2,7) separate with the cardboard of 7.5 millimeters thick, secondary coil (3,12) cardboard is passed in a termination (14), constituted a circle coil only round the iron core some (8) that is separated by cardboard through this termination (14), the sectional area of this a part of iron core (8) only account for whole core section long-pending 1/4, the test result of this current transformer is as follows:

When this when partly iron core (8) sectional area accounts for the long-pending ratio of whole core section and is 1/44 to 43/44, compensation effect is all arranged.

If do not adopt top measure of iron core being separated this moment with the fractional turns compensation, and adopt the compensation method that adds short circuit circle (4) on lower core post (2) secondary coil (3) separately, the short circuit circle is formed with stranded conductor, head and the tail are around one week of iron core, according to what of lead number of share of stock resistance value is adjusted into 0.0077 ohm again, head and the tail weld then, and the test result of this current transformer is as follows:

Table 3

If when the resistance value of lower core short circuit circle is a value between the Europe, 0.006 Europe to 0.0206, compensation effect is arranged all.

If on 0.5 grade of current transformer basis of LQG-0.5 type, both adopted this moment the iron core of equal state when recording table 2 to separate or the fractional turns compensation, adopt the iron core short circuited turn compensation of equal state when recording table 3 again, the test result after it is comprehensive is as follows:

Table 4

As can be seen from Table 4, current transformer LQG-0.5 type has compensated to 0.1 grade standard from former 0.5 grade standard.

Claims

1, a primary winding [1] and secondary coil some [12] that upper core post [7], lower core post [2], the upper core column sleeve that is changed by silicon steel sheet has, another part [3] of the secondary coil that the lower core column sleeve has, the magnetic shunt that compensating error is used [5], secondary coil reduces the current transformer of a circle and upper core short circuit circle [6] composition, it is characterized in that improving the improvement project that accuracy of measurement adopts, as following wherein any:

A had both adopted iron core had been separated into two parts or many parts with permeability material inequality [10], the thickness of its material [10] is between the 0.01mm to 10mm, make secondary coil have at least a circle to be combined to form the fractional turns [17] that compensating error is used around an iron core part [8] that is spaced, [9], [11], [13] or their other fractional turns, adopt the lower core post to add the short circuit circle [4] of suitable resistance again simultaneously

B only adopts separately iron core is separated into two parts or many parts with permeability material inequality [10], the thickness of its material [10] is to make secondary coil have at least a circle to form the fractional turns [17] that compensating error is used around an iron core part [8] that is spaced, [9], [11], [13] or their other fractional turns between the 0.01mm to 10mm

C only adopts separately and be with a short circuit circle [4] that compensating error is used that is used for suitable resistance on iron core column, and its Standard resistance range is between the Europe, 0.006 Europe to 0.0206.

2, by the current transformer of a in the claim 1 or b scheme defined, it is characterized in that permeability material (10) inequality that iron core is separated, can be permeability permeability magnetic materials inequality such as steel, alloy, other ferromagnetic material, also can be as nonmetallic materials such as paper, air, timber, plastics, electrical insulating materials, can also be the metal material as non-magnetic conductions such as copper, aluminium.

3, by the current transformer of a in the claim 1 or b scheme defined, it is characterized in that iron core is separated into two parts or many parts by permeability material inequality (10), this part core section that the fractional turns that the secondary coil compensating error is used is walked around amasss and accounts for the long-pending ratio of whole core section is between 1/44 to 43/44.