CN110767435A

CN110767435A - Combined current transformer

Info

Publication number: CN110767435A
Application number: CN201911043652.2A
Authority: CN
Inventors: 潘文韬; 吴昌松
Original assignee: Lujiang Herun Technology Co Ltd
Current assignee: Lujiang Herun Technology Co Ltd
Priority date: 2019-10-30
Filing date: 2019-10-30
Publication date: 2020-02-07

Abstract

The invention relates to a combined current transformer, which comprises two mutual inductance windings which are connected, namely a first mutual inductance winding and a second mutual inductance winding, wherein the first mutual inductance winding comprises a combined iron core, a first coil and a second coil, the first coil and the second coil are wound on the combined iron core, and the combined iron core is of an annular structure formed by splicing a plurality of combined units; the combined unit comprises an annular body with a triangular cross section, the annular body is divided into two symmetrically arranged parts, and the two parts of the annular body are detachably connected; the invention adopts a splicing combination structure, is convenient for processing and winding coils, can provide a circular section and a larger relative sectional area, and is worth popularizing.

Description

Combined current transformer

Technical Field

The invention belongs to the technical field of current transformers, and particularly relates to a combined current transformer.

Background

The current transformer is an instrument for measuring by converting a large primary side current into a small secondary side current according to the electromagnetic induction principle. The current transformer is composed of a closed iron core and a winding. The primary side winding of the transformer has few turns and is connected in a circuit of the current to be measured.

Therefore, all current of a line always flows through the current transformer, the number of turns of the secondary side winding is large, the secondary side winding is connected in series in the measuring instrument and the protection loop, and the secondary side loop of the current transformer is always closed when the current transformer works, so that the impedance of the series coil of the measuring instrument and the protection loop is small, and the working state of the current transformer is close to a short circuit. The current transformer converts a large current on the primary side into a small current on the secondary side for measurement, and the secondary side can not be opened.

The iron core of current transformer is the skeleton and the magnetic flow structure of mutual-inductor, iron core material self can produce certain magnetic resistance, cause no-load loss, reduce the loss and can reduce through increase relative sectional area, need adopt circular cross section, reach this requirement to the integral type iron core relatively easily, but be in the consideration of processing, the coiling and processing are changeed to the iron core of silicon steel sheet coincide, but generally adopt rectangle or special-shaped cross section to the iron core that the silicon steel sheet was folded, be difficult to reach the demand that reduces the loss.

Disclosure of Invention

The present invention is directed to solving the above-mentioned problems, and an object of the present invention is to provide a combined current transformer which is easy to wind a coil and has a large relative sectional area.

The invention realizes the purpose through the following technical scheme:

the combined type current transformer comprises two mutual inductance windings which are connected, namely a first mutual inductance winding and a second mutual inductance winding, wherein the first mutual inductance winding comprises a combined type iron core, a first coil and a second coil, the first coil and the second coil are wound on the combined type iron core, and the combined type iron core is of an annular structure formed by splicing a plurality of combined units.

As a further optimization scheme of the invention, the combination unit comprises annular bodies with triangular cross sections, the annular bodies are spliced to form a structure with a circular cross section, the annular bodies are divided into two parts which are symmetrically arranged, and the two parts of the annular bodies are detachably connected.

As a further optimized scheme of the present invention, the detachable connection between the ring bodies is an insertion connection, the two part ring bodies are respectively a first ring body and a second ring body, one end of the first ring body and one end of the second ring body are provided with a jack, the other end of the first ring body and the other end of the second ring body are provided with a plug matched with the jack, the plug of the first ring body is inserted into the jack of the second ring body when the first ring body and the second ring body are spliced, the plug of the second ring body is inserted into the jack of the first ring body, and the two are sequentially connected end to form a closed.

As a further optimization scheme of the invention, an insulating layer is arranged between the combined units. The contact resistance is reduced.

As a further optimized solution of the present invention, the second mutual inductance winding includes an integrated iron core, a third coil and a fourth coil, the third coil and the fourth coil are respectively wound around the integrated iron core and are respectively disposed on two sides of the integrated iron core, and the number of turns of the third coil is less than that of the fourth coil.

As a further optimized solution of the present invention, the joints of the first annular bodies and the second annular bodies of the plurality of combined cores are distributed in a staggered manner. Avoid the seam to concentrate, avoid the concentration of seam magnetic resistance, reduce the whole magnetic resistance of combination formula iron core.

As a further optimization scheme of the invention, the plurality of combination units are connected through a wedging mechanism, the wedging mechanism comprises a wedging groove and a wedging block which are arranged on the surface of an annular body, the outer side surface of the annular body is an arc surface, the two inner side surfaces are both provided with the wedging groove and the wedging block, the wedging groove and the wedging block on the same inner side surface are alternately distributed, and the other inner side surface of the corresponding position of the wedging groove is provided with the wedging block matched with the wedging groove. When all the combination units are spliced, the wedging blocks slide into the wedging grooves along the outer ends of the wedging grooves to form wedging, so that effective splicing connection is formed among the combination units.

As a further optimization scheme of the invention, the wedging grooves on the combined unit are arranged in parallel. The wedge blocks are also arranged in parallel.

As a further optimization scheme of the invention, no wedging mechanism is arranged at the positions of the first annular body and the second annular body close to the two ends, and the standard is that a closed annular structure formed by splicing the first annular body and an unclosed annular structure formed by the second annular body are not influenced.

The invention has the beneficial effects that:

1) the invention adopts a splicing combination structure, is convenient for processing and winding coils, can provide a circular section and a larger relative sectional area;

2) the invention adopts a staggered splicing mode to reduce the magnetic resistance at the joint;

3) the invention adopts the insertion mode for combination, and is convenient for assembly.

Drawings

FIG. 1 is a schematic structural diagram of the present invention in accordance with one embodiment;

fig. 2 is a plan view of a combined core according to the first embodiment of the present invention;

fig. 3 is a schematic cross-sectional view of a combined core according to the first embodiment of the present invention;

FIG. 4 is a schematic end view of a ring body according to one embodiment of the present invention;

FIG. 5 is a wiring and schematic diagram of the present invention in one embodiment;

fig. 6 is a schematic structural view of a combined core according to the second embodiment of the present invention;

fig. 7 is a schematic structural view of the annular body of the present invention according to the second embodiment.

In the figure: the combined type transformer core comprises a first mutual inductance winding 1, a second mutual inductance winding 2, a combined type iron core 3, a first coil 4, a second coil 5, a combined unit 6, an annular body 7, an inserting hole 8, an integrated type iron core 10, a third coil 11, a fourth coil 12, a joint 21, a wedging groove 31 and a wedging block 32.

Detailed Description

The present application will now be described in further detail with reference to the drawings, it should be noted that the following detailed description is given for illustrative purposes only and is not to be construed as limiting the scope of the present application, as those skilled in the art will be able to make numerous insubstantial modifications and adaptations to the present application based on the above disclosure.

Example one

As shown in fig. 1-5, the combined current transformer includes two mutual induction windings, which are a first mutual induction winding 1 and a second mutual induction winding 2, respectively, the first mutual induction winding 1 includes a combined iron core 3, a first coil 4 and a second coil 5, the combined iron core 3 is wound with the first coil 4 and the second coil 5, and the combined iron core 3 is formed by splicing a plurality of combined units 6 to form an annular structure.

The combined unit 6 comprises an annular body 7 with a triangular cross section, the annular body 7 is spliced to form a structure with a circular cross section, the annular body 7 is divided into two parts which are symmetrically arranged, and the two parts of the annular body 7 are detachably connected.

The detachable connection between the ring bodies 7 is splicing, the two part ring bodies 7 are respectively a first ring body and a second ring body, one end of the first ring body and one end of the second ring body are provided with jacks 8, the other end of the first ring body and the other end of the second ring body are provided with plugs 9 matched with the jacks 8, the plugs 9 of the first ring body are inserted into the jacks 8 of the second ring body when the first ring body and the second ring body are spliced, the plugs 9 of the second ring body are inserted into the jacks 8 of the first ring body, and the first ring body and the second ring body are sequentially connected end to end.

Preferably, three jacks 8 are arranged on the end face of the first annular body, the three jacks 8 are distributed in a delta shape, the three jacks 8 are separated by T-shaped ribs, and a plug 9 matched with the three jacks 8 is arranged on the other end face of the first annular body. The connection strength can be effectively maintained.

Preferably, three jacks 8 are arranged on the end face of the second annular body, the three jacks 8 are distributed in a delta shape, the three jacks 8 are separated by T-shaped ribs, and a plug 9 matched with the three jacks 8 is arranged on the other end face of the second annular body.

Preferably, an insulating layer is provided between the combined units 6. The contact resistance is reduced.

For the combination of the combined iron core 3, the first annular bodies of the plurality of combination units 6 are spliced to form an unclosed annular structure, the second annular bodies of the plurality of combination units 6 are spliced to form an unclosed annular structure, and coils are respectively wound on the unclosed annular structure formed by the closed annular bodies and the unclosed annular structure formed by the second annular bodies, so as to form a first coil 4 and a second coil 5.

And then splicing the closed annular structure formed by splicing the first annular body and the unclosed annular structure formed by the second annular body to form an annular structure.

The second mutual inductance winding 2 comprises an integrated iron core 10, a third coil 11 and a fourth coil 12, the third coil 11 and the fourth coil 12 are respectively wound on the integrated iron core 10 and are respectively arranged on two sides of the integrated iron core 10, and the number of turns of the third coil 11 is smaller than that of the fourth coil 12.

The working principle of the invention is as follows:

the power line passes through the center of the combined iron core 3, and the primary current I1 is in the power line. Under ideal working conditions, I1 × N1 ═ I2 × N2. Where I1 is the rated primary current, N1 is the 4 turns of the first coil, I2 is the rated secondary current, typically 5A or 1A, and N2 is the 5 turns of the second coil. When the first mutual inductance winding 1 passes through the primary current I1, an induced potential is generated in the second coil 5 due to electromagnetic induction, when the first mutual inductance winding 1 is connected with the secondary load Zn, a secondary current I2 flows, the primary current in the power circuit is different, and the primary current is generally different from the secondary current of 5A or 1A of a standard through the configuration of the turn ratio between the 4 turns N1 of the first coil and the 5 turns N2 of the second coil of the first mutual inductance winding 1. When a primary current I1 flows through the first mutual inductance winding 1 of the first coil 4, N1, a primary magnetic potential, also called an ampere-turn, will be established. Similarly, the product of the secondary current I2 and the number of turns N2 of the secondary winding is a secondary ampere turn, and the primary ampere turn is equal to the secondary ampere turn. The first mutual inductance winding 1 secondary current I2(5A) flows through the second mutual inductance winding 2 wound with 4 turns of the third coil 11, and a current I3(20mA) is induced by the second mutual inductance winding 2 wound with 1000 turns of the fourth coil 12, so that according to the principle, I3 ═ I2 × 4 ÷ 1000 ═ 5 × 4 ═ 0.02A, namely 20mA can be obtained; if the secondary current I2(1A) flows through the second transformer winding 2 with 20 turns, and the second transformer winding 2 induces the current I3 through 1000 turns of the winding, it can be found that I3 ═ I2 × 20 ÷ 1000 ═ 1 × 20 ÷ 1000 ÷ 0.020A ═ 20mA, so that the primary ampere turn of the second transformer winding 2 is equal to the secondary ampere turn which is equal to 20 ampere turns.

Example two

As shown in fig. 6, on the basis of the first embodiment, the joints 21 of the first annular bodies and the second annular bodies of the plurality of combined cores 3 are distributed in a staggered manner. The concentration of the joint 21 is avoided, the concentration of the magnetic resistance of the joint 21 is avoided, and the overall magnetic resistance of the combined iron core 3 is reduced.

The included angle between the seams 21 of the combined iron cores 3 is 5-10 degrees.

EXAMPLE III

As shown in fig. 7, the combined current transformer includes two mutual induction windings, which are a first mutual induction winding 1 and a second mutual induction winding 2, respectively, the first mutual induction winding 1 includes a combined iron core 3, a first coil 4 and a second coil 5, the combined iron core 3 is wound with the first coil 4 and the second coil 5, and the combined iron core 3 is formed by splicing a plurality of combined units 6 to form an annular structure.

The combination unit 6 comprises an annular body 7 with a triangular cross section, the annular body 7 is divided into two parts which are symmetrically arranged, and the two parts of the annular body 7 are detachably connected.

The plurality of combination units 6 are connected through a wedging mechanism, the wedging mechanism comprises a wedging groove 31 and a wedging block 32 which are arranged on the surface of the annular body 7, the outer side surface of the annular body 7 is a cambered surface, the two inner side surfaces are respectively provided with the wedging groove 31 and the wedging block 32, the wedging groove 31 and the wedging block 32 on the same inner side surface are alternately distributed, and the other inner side surface of the corresponding position of the wedging groove 31 is provided with the wedging block 32 matched with the wedging groove 31. When the combined units 6 are spliced, the wedging blocks 32 slide into the wedging grooves 31 along the outer ends of the wedging grooves 31 to form wedging, so that effective splicing connection is formed among the combined units 6.

Preferably, the wedging grooves 31 on the combined unit 6 are arranged parallel to each other. The wedge blocks 32 are also arranged parallel to each other.

And necessarily, no wedging mechanism is arranged at the positions close to the two ends of the first annular body and the second annular body, so that the standard that the closed annular structure formed by splicing the first annular body and the unsealed annular structure formed by splicing the second annular body are not influenced is taken as a standard.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention.

Claims

1. Combined type current transformer, its characterized in that: the transformer comprises two mutual inductance windings which are connected with each other and are respectively a first mutual inductance winding and a second mutual inductance winding, wherein the first mutual inductance winding comprises a combined iron core, a first coil and a second coil, the first coil and the second coil are wound on the combined iron core, and the combined iron core is of an annular structure formed by splicing a plurality of combined units.

2. The combined current transformer of claim 1, wherein: and an insulating layer is arranged between the combined units.

3. The combined current transformer of claim 1, wherein: the second mutual inductance winding comprises an integrated iron core, a third coil and a fourth coil, the third coil and the fourth coil are respectively wound on the integrated iron core and are respectively arranged on two sides of the integrated iron core, and the number of turns of the third coil is smaller than that of the fourth coil.

4. The combined current transformer of claim 1, wherein: the combined unit comprises annular bodies with triangular cross sections, the annular bodies are spliced to form a structure with a circular cross section, the annular bodies are divided into two symmetrically arranged parts, and the two parts of the annular bodies are detachably connected.

5. The combined current transformer of claim 4, wherein: the detachable connection between the ring bodies is splicing, the two part ring bodies are respectively a first ring body and a second ring body, one end of the first ring body and one end of the second ring body are provided with jacks, the other end of the first ring body and the other end of the second ring body are provided with plugs matched with the jacks, the plug of the first ring body is inserted into the jack of the second ring body when the first ring body and the second ring body are spliced, the plug of the second ring body is inserted into the jack of the first ring body, and the first ring body and the second ring body are sequentially connected end to form.

6. The combined current transformer of claim 4, wherein: the joints of the first annular bodies and the second annular bodies of the plurality of combined iron cores are distributed in a staggered mode.

7. The combined current transformer of claim 4, wherein: the combined units are connected through a wedging mechanism, the wedging mechanism comprises a wedging groove and a wedging block which are arranged on the surface of an annular body, the outer side surface of the annular body is an arc surface, the two inner side surfaces are respectively provided with the wedging groove and the wedging block, the wedging groove and the wedging block on the same inner side surface are alternately distributed, and the other inner side surface of the corresponding position of the wedging groove is provided with the wedging block matched with the wedging groove.

8. The combined current transformer of claim 7, wherein: the wedging grooves on the combination unit are arranged in parallel.

9. The combined current transformer of claim 7, wherein: and wedge-fit mechanisms are not arranged at the parts of the first annular body and the second annular body, which are close to the two ends.