Current transformer capable of being externally connected with electrified display device

Abstract

The invention relates to the field of structures of current transformers, in particular to a current transformer capable of being externally connected with an electrified display device. A current transformer capable of being externally connected with an electrified display device comprises a shell, a secondary winding is arranged in the shell, an insulating coating layer for integrally coating the secondary winding is arranged on the surface of the secondary winding, and the current transformer further comprises a metal conductor which is tightly attached to or close to the insulating coating layer of the secondary winding. The metal conductor has a radial length on the axial projection surface of the secondary winding, cuts a magnetic induction line to obtain induced electromotive force, and is also used for being electrically connected with an electrified display device, so that the electrified display device can perform electrified display; the problems that in the prior art, a current transformer capable of being directly connected with an electrified display device is high in manufacturing cost and large in assembly difficulty are solved.

Description

Technical Field

[0001] The present invention relates to the field of current transformer structures, and in particular to a current transformer capable of being externally connected to a live display device. Background Art

[0002] In the prior art, a current transformer generates a corresponding magnetic field through the flow of current on the high-voltage side. Under the action of this magnetic field, the low-voltage side senses current and feeds back a corresponding signal to the control system, thereby determining whether the high-voltage side is energized and how much current is flowing. However, the current transformer receives and feeds back an electrical signal, and the electrical signal is fed back directly to the control system. Therefore, on-site operators cannot intuitively observe whether the corresponding line is energized. Therefore, a relatively intuitive device is needed in this field to prompt on-site operators and determine whether the corresponding line is energized. In the case of incoming busbars, circuit breakers, main transformers, switch cabinets, GIS combination electrical appliances, and other places where it is necessary to display whether the line is energized, a live display device is the most effective device for intuitively determining whether the corresponding line is energized.

[0003] A Chinese utility model patent with authorization announcement number CN218730382U discloses a current transformer with a live display function, comprising a packaging material, a primary coil and a secondary coil disposed within the packaging material, a high-voltage capacitor and a low-voltage capacitor disposed within the packaging material connected in series on the primary coil, a display disposed on the outside of the packaging material connected between the high-voltage capacitor and the low-voltage capacitor via a wire, the primary coil being connected via wires to a first primary terminal and a second primary terminal disposed on the outside of the packaging material, and the secondary coil being connected via wires to a secondary terminal disposed on the outside of the packaging material. However, the technical solution disclosed in the patent requires the use of two capacitors in conjunction with each other and connecting the capacitors to the first winding, which results in a high cost for the entire device and greater difficulty in assembly. Summary of the Invention

[0004] The object of the present invention is to provide a current transformer that can be externally connected to a live display device, so as to solve the problems in the prior art of high production cost and great assembly difficulty of current transformers that can be directly connected to a live display device.

[0005] A current transformer capable of being externally connected to a live-charge display device comprises a housing, a secondary winding disposed within the housing, an insulating coating disposed on the surface of the secondary winding that entirely encapsulates the secondary winding, the current transformer further comprising a metal conductor in close contact with or adjacent to the insulating coating of the secondary winding, the metal conductor having a radial length on an axial projection of the secondary winding and cutting magnetic flux lines to obtain an induced electromotive force, the metal conductor further being used to electrically connect to the live-charge display device, enabling the live-charge display device to display live charges.

[0006] Furthermore, the metal conductor is in close contact with the surface of the insulating coating on the axial side surface of the secondary winding.

[0007] Further, the metal conductor is provided at one of the axial side surfaces of the secondary winding.

[0008] Furthermore, the axial cross-section of the secondary winding is rectangular, and the radial length of the metal conductor on the axial projection plane of the secondary winding is equal to the length of the metal conductor.

[0009] Furthermore, the secondary winding also includes semiconductor corrugated paper wrapped on the surface of the insulating coating of the secondary winding. The metal conductor is arranged between the semiconductor corrugated paper and the insulating coating and is pressed against the insulating coating by the semiconductor corrugated paper.

[0010] Furthermore, the connection end of the metal conductor is adjacent to the tap of the secondary winding.

[0011] Furthermore, a metal conductor is provided.

[0012] Furthermore, the metal conductor is a flat bare copper wire.

[0013] Furthermore, the insulating coating layer is a polyester film.

[0014] The present invention improves the existing technology. Specifically, the current transformer in the technical solution of the present invention is equipped with a corresponding metal conductor on the basis of the existing technology. The metal conductor is adjacent to or close to the insulating sheath of the secondary winding. Since the iron core inside the current transformer can also induce a secondary current in the low-voltage coil through excitation when the primary circuit is energized, there is a uniformly changing magnetic field around the iron core. The metal conductor has a radial length on the axial projection surface of the secondary winding and cuts the magnetic flux lines to obtain an induced electromotive force, thereby enabling the charged display device to obtain voltage and make the charged display device light up. And since the present invention forms a power supply structure for the charged display device by cooperating with the secondary winding through the additional metal conductor, the present invention is relatively lower in cost and easier to assemble, solving the problem of high production cost and difficulty in assembly of the current transformer that can be directly connected to the charged display device in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 : a rear view of the secondary winding of an embodiment of a current transformer capable of being externally connected to a charge display device according to the present invention; Figure 2 : A cross-sectional view of a secondary winding of an embodiment of a current transformer capable of being externally connected to a charge display device according to the present invention; Figure 3 : a schematic diagram of the overall structure of an embodiment of a current transformer capable of being externally connected to a charge display device according to the present invention; In the figure: 1. Shell; 2. Secondary winding; 3. Insulation coating; 4. Metal conductor; 5. Tap; 6. Insert; 7. Semiconductor corrugated paper. DETAILED DESCRIPTION

[0016] The specific concept of the current transformer of the present invention that can be externally connected to a charge display device is as follows: A current transformer capable of being externally connected to a live-charge display device comprises a housing, a secondary winding disposed within the housing, an insulating coating disposed on the surface of the secondary winding that entirely encapsulates the secondary winding, the current transformer further comprising a metal conductor in close contact with or adjacent to the insulating coating of the secondary winding, the metal conductor having a radial length on an axial projection of the secondary winding and cutting magnetic flux lines to obtain an induced electromotive force, the metal conductor further being used to electrically connect to the live-charge display device, enabling the live-charge display device to display live charges.

[0017] The present invention improves the existing technology. Specifically, the technical solution of the present invention is to add a corresponding metal conductor to the secondary winding on the current transformer, and the metal conductor is adjacent to or close to the insulating sheath of the secondary winding of the current transformer. Since the iron core inside the current transformer can also induce a secondary current in the low-voltage coil through excitation when the primary circuit is energized, there is a uniformly changing magnetic field around the iron core at this time, and the metal conductor has a radial length on the axial projection surface of the secondary winding, so the metal conductor can cut the magnetic flux lines to obtain an induced electromotive force, thereby allowing the charged display device to obtain voltage. The charged display device emits light after receiving the signal that the current transformer is energized. The present invention adds a metal conductor to the secondary coil, and the coordination of the metal conductor and the secondary coil allows the charged display device to obtain a signal. Compared with the existing technology, the present invention has lower cost and lower assembly difficulty, solving the problem of high production cost and high assembly difficulty of current transformers that can be directly connected to charged display devices.

[0018] The features and performance of the present invention are further described in detail below with reference to the embodiments.

[0019] like Figure 1-3 As shown: A current transformer that can be externally connected to a charge display device includes a housing 1, a secondary winding 2 is arranged in the housing 1, and an insulating coating 3 is provided on the surface of the secondary winding 2 to entirely cover the secondary winding 2. The current transformer also includes a metal conductor 4 that is closely attached to or adjacent to the insulating coating 3 of the secondary winding 2. The metal conductor 4 has a radial length on the axial projection surface of the secondary winding 2 and cuts the magnetic flux lines to obtain an induced electromotive force. The metal conductor 4 is also used to electrically connect to the charge display device, so that the charge display device can display the charge.

[0020] The metal conductor 4 can be made of a suitable metal material, such as iron, aluminum, silver, or copper. However, considering the conductivity and price of the corresponding material, the metal conductor 4 is made of copper. Furthermore, to better cut the magnetic flux lines and thereby generate a higher electromotive force to provide a signal for the charged display device, the metal conductor 4 is a flat bare copper wire, with the larger side of the flat bare copper wire facing the secondary winding 2.

[0021] The metal conductor 4 can be located at a certain distance from the secondary winding 2. For example, the housing 1 of the voltage transformer is provided with two corresponding brackets: one for mounting the secondary winding 2, and the other for mounting the corresponding metal conductor 4. The secondary winding 2 and the metal conductor 4 are mounted on the corresponding brackets, and the metal conductor 4 is adjacent to the axial side of the secondary winding 2. The metal conductor 4 has a radial length in the axial projection of the secondary winding 2. However, because the metal conductor 4 cuts the magnetic field generated by the current generated by the excitation of the secondary winding 2's core, thereby generating an electromotive force, in order to ensure that the charge indicator device obtains a more accurate signal, it is preferred that the metal conductor 4 be closely attached to the surface of the insulating coating 3 on the axial side of the secondary winding 2, with the other end extending out of the secondary winding 2 to form a terminal for electrical connection to the charge indicator device. The close proximity of the metal conductor 4 to the secondary winding 2 significantly reduces the distance between them, resulting in a relatively larger magnetic field in the area where the metal conductor 4 is located. This results in a larger electromotive force for the metal conductor 4, and a larger and more accurate signal for the charge indicator device. This prevents the situation where the corresponding line is actually energized but the charge indicator device does not return a corresponding signal.

[0022] The metal conductor 4 only needs to be in close contact with the axial side of the secondary winding 2, so the metal conductor 4 can be C-shaped or U-shaped, and be in close contact with the two axial sides of the secondary winding 2. However, based on the principle that no electromotive force can be obtained by cutting the magnetic flux lines after the metal conductor 4 forms a complete ring, which is known to those skilled in the art, the metal conductor 4 cannot be formed into a complete ring or a structure similar to a winding. However, if a C-shaped or U-shaped metal conductor 4 is used, it is necessary to make the secondary winding 2 and wrap the insulating coating 3, and then make the corresponding metal conductor 4 according to the winding. The production difficulty of the metal conductor 4 is relatively large. Therefore, preferably: the metal conductor 4 is arranged to fit one of the axial sides of the secondary winding 2. The metal conductor 4 only fits one of the axial sides of the secondary winding 2, which means that the metal conductor 4 only needs to fit with this side surface, so the metal conductor 4 does not need to undergo additional processing and can be directly connected to the corresponding axial side.

[0023] In the prior art, the shape of the secondary winding 2 is determined according to the shape of the iron core, and there are generally two types: one with a rectangular cross-section and the other with a circular cross-section. In this embodiment, an iron core with a rectangular axial cross-section is used. Since the metal conductor 4 is in close contact with the insulating layer on the surface of the secondary winding 2, if the cross-section of the secondary winding 2 is circular, the metal conductor 4 will be arc-shaped. Under the condition of equal radial dimensions, the effective length of the metal conductor 4 cutting the magnetic flux lines will be relatively short. Therefore, preferably, the cross-section of the secondary winding 2 is rectangular. The cross-section of the secondary winding 2 is rectangular, and the radial length of the metal conductor 4 on the axial projection plane of the secondary winding 2 is equal to the length of the metal conductor 4. With such a setting, the effective distance of the conductor cutting the magnetic flux lines is guaranteed as much as possible, thereby ensuring that a sufficiently high induced electromotive force can be obtained in the metal conductor 4.

[0024] For further optimization, the secondary winding 2 also includes semiconductor corrugated paper 7 wrapped around the surface of the insulating coating 3 of the secondary winding 2. The metal conductor 4 is disposed between the semiconductor corrugated paper 7 and the insulating coating 3 and is pressed against the insulating coating 3 by the semiconductor corrugated paper 7. The semiconductor corrugated paper 7 must not have any breaks, and preferably, a single sheet of semiconductor corrugated paper 7 is used. The semiconductor corrugated paper 7 envelops the entire secondary winding 2, preventing it from interfering with the external electric field and thereby ensuring that local discharge does not occur under the influence of the high-voltage side. Furthermore, since the metal conductor 4 is an additional structure, it is disposed between the semiconductor corrugated paper 7 and the insulating coating 3 to prevent it from affecting the external magnetic field. Simultaneously, the semiconductor corrugated paper 7 presses the metal conductor 4 against the insulating coating 3, thereby securing the metal conductor 4.

[0025] Furthermore, since the surface of the secondary winding 2 is coated with the corresponding semiconductor corrugated paper 7, to prevent breakdown, the end of the semiconductor corrugated paper 7 needs to be at least 20 mm away from the secondary tap 5 during coating. Therefore, for further optimization, the connection end of the metal conductor 4 is adjacent to the tap 5 of the secondary winding 2. If the distance between the connection end of the metal conductor 4 and the tap 5 of the secondary winding 2 is too large, two sheets of corrugated paper will be needed when coating the semiconductor corrugated paper 7. Furthermore, since sufficient space must be left for the connection end of the metal conductor 4 to electrically connect the metal conductor 4 to the energized display device, it may be impossible to ensure the spacing between the end of the semiconductor corrugated paper 7 and the tap 5 of the secondary winding 2. Furthermore, using two sheets of semiconductor corrugated paper 7 for coating is relatively cumbersome. Therefore, preferably, the connection end of the metal conductor 4 is adjacent to the tap 5 of the secondary winding 2, and the secondary winding is coated with a single sheet of semiconductor corrugated paper 7.

[0026] For further optimization, only one metal conductor 4 is provided. Multiple metal conductors 4 are possible, but they must be connected by wires, which are then connected to the charge indicator. However, using multiple metal conductors 4 makes connecting the wires relatively difficult, and the wires are also difficult to secure. Therefore, preferably, only one metal conductor 4 is provided. The connection end of the metal conductor 4 extends beyond the secondary winding 2 and is also fitted with a metal insert 6 for connection to the charge indicator.

[0027] To further optimize the insulation performance, the insulating coating 3 is made of polyester film, which has relatively good insulation properties and is relatively thin. Of course, in other embodiments, polytetrafluoroethylene film or polyethylene film, etc., may also be used. In this embodiment, to ensure the appropriate insulation performance, two layers of polyester film are used to coat the secondary winding 2.

[0028] During assembly, first coat the secondary winding 2 with polyester film, then place the metal conductor 4 firmly against the axial side of the secondary winding 2. Wrap the semiconductor crepe paper 7 around the secondary winding 2 to secure the metal conductor 4. The entire secondary winding 2 is then installed into the current transformer housing 1. The tap 5 of the secondary winding 2 and the metal conductor 4 are positioned so that they align with the designated locations on the housing 1 for electrical connection between the tap 5 and the metal conductor 4. Epoxy resin is then poured into the housing.

[0029] During operation, the current transformer is first connected to the circuit, and then the charge indicator is connected to the insert 6 of the metal conductor 4. If the circuit needs to be repaired, the charge indicator can be used to determine whether the corresponding circuit is energized. Of course, if the charge indicator is not connected, the metal conductor 4 can be directly grounded without affecting the normal operation of the current transformer.

[0030] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be based on the claims. Any equivalent structural changes made using the description and drawings of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A current transformer capable of being connected to an external current display device, comprising a housing, a secondary winding disposed within the housing, and an insulating coating disposed on the surface of the secondary winding to entirely enclose the secondary winding, characterized in that: The current transformer also includes a metal conductor that is closely attached to or adjacent to the insulating coating of the secondary winding. The metal conductor has a radial length on the axial projection surface of the secondary winding and cuts the magnetic flux lines to obtain an induced electromotive force. The metal conductor also has a connection end for electrically connecting to a charge display device, so that the charge display device can display charge.

2. The current transformer capable of being connected to an external current display device according to claim 1, characterized in that: The metal conductor is in close contact with the surface of the insulating coating on the axial side of the secondary winding.

3. The current transformer capable of being connected to an external charge display device according to claim 2, characterized in that: The metal conductor is provided at one axial side surface of the secondary winding.

4. The current transformer capable of being connected to an external current display device according to claim 2 or 3, characterized in that: The axial cross-section of the secondary winding is rectangular, and the radial length of the metal conductor on the axial projection plane of the secondary winding is equal to the length of the metal conductor.

5. The current transformer capable of being externally connected to a charge display device according to any one of claims 1 to 3, characterized in that: The secondary winding further comprises semiconductor corrugated paper wrapped on the surface of the insulating coating of the secondary winding. The metal conductor is arranged between the semiconductor corrugated paper and the insulating coating and is pressed onto the insulating coating by the semiconductor corrugated paper.

6. The current transformer capable of being connected to an external current display device according to claim 5, characterized in that: The connection end of the metal conductor is adjacent to the tap of the secondary winding.

7. The current transformer capable of being connected to an external current display device according to any one of claims 1 to 3, characterized in that: The metal conductor is provided with one.

8. The current transformer capable of being connected to an external current display device according to any one of claims 1 to 3, characterized in that: The metal conductor is a flat bare copper wire.

9. The current transformer capable of being connected to an external current display device according to any one of claims 1 to 3, characterized in that: The insulating coating layer is a polyester film.

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