CN202258767U

CN202258767U - Current transformer

Info

Publication number: CN202258767U
Application number: CN2011204084008U
Authority: CN
Inventors: 薛晚道; 张伟明; 王文娣; 刘秀凤; 于昕; 孙红萍
Original assignee: Baoding Tianwei Group Co Ltd
Current assignee: Baoding Tianwei Group Co Ltd
Priority date: 2011-10-25
Filing date: 2011-10-25
Publication date: 2012-05-30
Anticipated expiration: 2021-10-25

Abstract

The utility model relates to a current transformer, in particular to the current transformer installed on a transformer-body lead, which belongs to the technical field of transformers. The technical scheme is that: the current transformer comprises an iron core (1), an insulator (2), a secondary winding (3) and a shielded winding (4), wherein one or a plurality of air gaps are arranged on the iron core, the insulator is wound on the iron core, the secondary winding is wound outside, and the shielded winding is then wound outside the secondary winding. The shielded winding comprises a plurality of paired windings, so that the electric potentials of a main magnetic flux induced in the shielded winding are mutually counteracted, circular current is formed by utilizing the electric potential generated from the difference of magnetic fluxes generated by the leakage magnetic field of the transformer at all the parts of the iron core to reduce the influence of the leakage magnetic field of the transformer, and the influence of the magnetic leakage of the transformer is minimized, so that the iron core is not easily saturated. The current transformer has the positive effects that: the current transformer is installed on the transformer-body lead; and when excitation surge current or short-circuit current passes, the specified accuracy of the current transformer can be ensured without protecting malfunction, and the safety of an electrical network is ensured.

Description

A kind of current transformer

Technical field

The utility model relates to a kind of current transformer, particularly is installed in the current transformer on the transformer body lead-in wire, belongs to the instrument transformer technical field.

Background technology

The transformer Current Transformer generally is contained in the rising seat of oil tank of transformer, also has to be installed on the device body lead-in wire.This moment, the leakage field of transformer possibly exert an influence to the class of accuracy of current transformer, and leakage field was less when transformer normally moved, when transformer put into operation, out of service or when external short circuit takes place; Magnetizing inrush current or short circuit current are bigger, and DC component is arranged, and the transformer leakage field is also very big; Add the effect of DC component, might make current transformer unshakable in one's determination local saturated, influence the accuracy of current transformer; And then cause the protection misoperation, the safe operation of electrical network is caused very big threat.

The utility model content

The purpose of the utility model provides a kind of current transformer, is installed on the transformer body lead-in wire, when magnetizing inrush current or short circuit current flow through; Current transformer can guarantee the accuracy of regulation; Unlikely protection misoperation, the safety of assurance electrical network solves the problems referred to above that background technology exists.

The technical scheme of the utility model is: a kind of current transformer; Be installed on the transformer body lead-in wire, comprise iron core, insulation, secondary winding and shielding winding, one or several air gaps are set on the iron core; On iron core, twine insulation; Secondary winding is twined in the outside, twines the shielding winding again in the outside of secondary winding, and this current transformer is installed in the transformer body lead-in wire and goes up use.

The utility model is provided with one or several air gaps on the iron core of current transformer; To reduce remanent magnetism unshakable in one's determination, remanent magnetism is limited in the lower scope, add around the shielding winding in the secondary winding outside simultaneously; Said shielding winding is several paired windings; The electromotive force that main flux is responded to is therein cancelled each other, and utilizes Magnetic Leakage Field of Transformer to form circulation in the electrical potential difference that difference produced of the magnetic flux of various piece generation unshakable in one's determination, to reduce the influence of Magnetic Leakage Field of Transformer; The influence of transformer leakage field is dropped to minimum, it is saturated that iron core is not easy.

Be chosen to right shielding umber of turn, around cancelling each other to the electromotive force that main flux is responded to therein with bind mode, reduce of the influence of transformer leakage field to current transformer.

The good effect of the utility model: be installed on the transformer body lead-in wire, when magnetizing inrush current or short circuit current flow through, current transformer can guarantee the accuracy stipulated, unlikely protection misoperation, the safety of assurance electrical network.

Description of drawings

Fig. 1 is the embodiment sketch map of the utility model;

Among the figure: iron core 1, insulation 2, secondary winding 3 and shielding winding 4.

Embodiment

Below in conjunction with accompanying drawing, the utility model is further specified through embodiment.

A kind of current transformer; Be installed on the transformer body lead-in wire, comprise iron core 1, insulation 2, secondary winding 3 and shielding winding 4, on the iron core 1 one or several air gaps are set; On iron core, twine insulation 2; Secondary winding 3 is twined in the outside, twines shielding winding 4 again in the outside of secondary winding 3, and this current transformer is installed in the transformer body lead-in wire and upward uses.

Claims

1. current transformer; Be installed on the transformer body lead-in wire; It is characterized in that comprising iron core (1), insulation (2), secondary winding (3) and shielding winding (4), one or several air gaps are set on the iron core, on iron core, twine insulation; Secondary winding is twined in the outside, twines the shielding winding again in the outside of secondary winding.

2. a kind of current transformer according to claim 1 is characterized in that said shielding winding is several paired windings.