CN221225973U - High-frequency transformer and power supply equipment - Google Patents

Abstract

The application discloses a high-frequency transformer and power supply equipment, which relate to the technical field of electrical components. The high-frequency transformer and the power supply equipment provided by the application can reduce the actual on-resistance of the copper sheet and reduce the loss.

Description

High-frequency transformer and power supply equipment

Technical Field

The application relates to the technical field of electrical components, in particular to a high-frequency transformer and power supply equipment.

Background

The transformer is a device for changing an ac voltage by using the principle of electromagnetic induction, and the main components are a primary coil, a secondary coil and an iron core. The main functions are as follows: voltage transformation, current transformation, impedance transformation, isolation, voltage stabilization, etc. The method can be divided into the following according to the purposes: power transformers and special transformers (electric furnace transformers, rectifier transformers, power frequency test transformers, voltage regulators, mining transformers, audio transformers, medium frequency transformers, high frequency transformers, impact transformers, instrument transformers, electronic transformers, reactors, transformers, etc.). The high-frequency transformer is a power transformer with the working frequency exceeding 10kHz, is mainly used as a high-frequency switching power transformer in a high-frequency switching power supply, and is also used as a high-frequency inversion power transformer in a high-frequency inversion power supply and a high-frequency inversion welding machine.

In the prior art, a high-frequency transformer comprises a circuit board, a magnetic core is arranged on the circuit board, a primary winding and a secondary winding are wound on the magnetic core, and the number of turns of the primary winding is different from that of the secondary winding so as to realize transformation. In practical application, in order to increase the number of secondary windings, a copper sheet is wrapped on the primary winding or the outer ring of the secondary winding, wherein the copper sheet is a secondary winding of the transformer and corresponds to a winding with one turns, and the copper sheet can be used as a group of components for assisting in heat dissipation because copper has better heat conductivity; the second output voltage is also extended by the matching circuit. However, the copper sheet has a larger current cross-sectional area, and when the copper sheet is applied to a magnetic field with high-frequency variation, skin effect exists, namely, current flows along the periphery of the cross section, and the cross section of the copper sheet cannot be fully utilized, so that the actual on-resistance of the copper sheet is increased, and the loss is further increased.

Disclosure of utility model

The application aims to provide a high-frequency transformer and power supply equipment, which can reduce the actual on-resistance of a copper sheet and reduce loss.

In one aspect, the embodiment of the application provides a high-frequency transformer, which comprises a circuit board and a magnetic core arranged on the circuit board, wherein a primary winding and a first secondary winding are wound on the magnetic core, the primary winding and the first secondary winding are respectively connected with the circuit board, and/or a sheet-shaped second secondary winding is also coated outside the first secondary winding, two ends of the second secondary winding are respectively connected with the circuit board so as to form current between two ends of the second secondary winding, and a dividing structure is arranged on the second secondary winding so as to divide the cross section of the second secondary winding perpendicular to the current flow direction.

As an embodiment, the dividing structure comprises a plurality of through holes distributed over the second secondary winding, and at least two through holes are included in a cross section perpendicular to the current flow direction to divide the cross section perpendicular to the current flow direction into a plurality of sub-faces.

As an embodiment, the plurality of through holes are arranged in a plurality of rows along the current flow direction, and the through holes of two adjacent rows are arranged in a staggered manner, or the plurality of through holes are distributed in a determinant.

As an implementation manner, the second secondary winding is one and is wrapped outside the primary winding.

As an embodiment, the dividing structure includes a plurality of through slots arranged along the current flow direction, the plurality of through slots dividing the second secondary winding into a plurality of winding bars.

As an embodiment, the cross-section of the two ends of the winding strand is reduced for the plug connection to the circuit board.

As an embodiment, two adjacent winding bars are connected by a connection point so that a plurality of winding bars are integrated.

As an embodiment, the plurality of connection points are located on the same line.

As an implementation manner, the second secondary winding is a copper sheet, and the copper sheet is in a U shape.

Another aspect of the embodiments of the present application provides a power supply apparatus including the above high frequency transformer.

The beneficial effects of the embodiment of the application include:

The application provides a high-frequency transformer, which comprises a circuit board and a magnetic core arranged on the circuit board, wherein a primary winding and a first secondary winding are wound on the magnetic core, the primary winding and the first secondary winding are respectively connected with the circuit board, and/or a sheet-shaped second secondary winding is also coated outside the first secondary winding, two ends of the second secondary winding are respectively connected with the circuit board so as to form current between two ends of the second secondary winding, and a dividing structure is arranged on the second secondary winding so as to divide the cross section of the second secondary winding perpendicular to the current flow direction. The split structure is arranged on the flaky second secondary winding, and the split structure splits the cross section of the second secondary perpendicular to the current flow direction into a plurality of sub-surfaces, so that current flows along the plurality of sub-surfaces respectively, the cross section area when the current flows is reduced, the problem that the conduction resistance is increased due to the skin effect is avoided, the conduction resistance is reduced, and the loss is further reduced.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a high-frequency transformer according to an embodiment of the present application;

fig. 2 is a second schematic diagram of a high-frequency transformer according to an embodiment of the present application;

Fig. 3 is a third schematic structural diagram of a high-frequency transformer according to an embodiment of the present application;

Fig. 4 is a schematic structural diagram of a second secondary winding according to an embodiment of the present application;

FIG. 5 is a schematic diagram of a second secondary winding cross-sectional current distribution in the prior art;

fig. 6 is a schematic diagram of a second secondary winding cross-sectional current distribution in an embodiment of the application.

Icon: 10-high frequency transformers; 11-a circuit board; 111-magnetic core; 12-primary winding; 13-a first secondary winding; 14-a second secondary winding; 15-through holes; 161-through grooves; 162-winding bars; 163-connection point.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application. The components of the embodiments of the present application generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the application, as presented in the figures, is not intended to limit the scope of the application, as claimed, but is merely representative of selected embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.

In the description of the present application, it should also be noted that, unless explicitly stated and limited otherwise, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art.

In the high-frequency circuit, the change rate of the current is larger, so that the current is unevenly distributed in the conductor, specifically, the magnetic field generated by the high-frequency current in the conductor induces the largest electromotive force in the central area of the conductor, the electromotive force resists the passing of the current, the current density in the central area of the conductor is minimized, the current is mainly concentrated in a thin layer outside the conductor, namely, the closer to the surface of the conductor, the larger the current density is, and the smaller the current actually flows in the conductor.

The embodiment of the application provides a high-frequency transformer 10, as shown in fig. 1, 2 and 3, which comprises a circuit board 11 and a magnetic core 111 arranged on the circuit board 11, wherein a primary winding 12 and a first secondary winding 13 are wound on the magnetic core 111, the primary winding 12 and the first secondary winding 13 are respectively connected with the circuit board 11, and/or the first secondary winding 13 is also coated with a sheet-shaped second secondary winding 14, two ends of the second secondary winding 14 are respectively connected with the circuit board 11 to form current between two ends of the second secondary winding 14, and a dividing structure is arranged on the second secondary winding 14 to divide a cross section of the second secondary winding 14 perpendicular to the current flow direction.

When the high-frequency transformer 10 provided by the embodiment of the application works, an alternating input signal is input on the primary winding 12 through the circuit board 11, the magnetic core 111 forms a magnetic field around magnetism, alternating magnetic flux is generated in the input signal, the magnetic flux passes through the first secondary winding 13 and the second secondary winding 14, and an alternating output signal is generated in the first secondary winding 13 and the second secondary winding 14. The second secondary winding 14 is sheet-shaped, and since the high-frequency transformer 10 of the present application is applied to high-frequency alternating signals, the output signals have skin effect in the first secondary winding 13 and the second secondary winding 14, so that current propagates along the surfaces of the first secondary winding 13 and the second secondary winding 14, wherein when the second secondary winding 14 is sheet-shaped, and a dividing structure is arranged on the sheet-shaped second secondary winding 14, the dividing structure divides the cross section of the second secondary winding 14 perpendicular to the current flow direction to divide the cross section perpendicular to the current flow direction into a plurality of sub-surfaces, as shown in fig. 6, so that current flows through the plurality of sub-surfaces, the cross section perpendicular to the current flow direction is reduced, and compared with fig. 5 of the prior art, fig. 6 can fully utilize the cross section of the sub-surfaces, avoid the problem of impedance increase caused by skin effect, reduce the on-resistance, and further reduce loss.

It should be appreciated by those skilled in the art that, when the high-frequency transformer 10 is in operation, heat is usually generated, in the prior art, the high-frequency transformer 10 further includes a housing fastened to the circuit board 11 to protect the magnetic core 111 and each winding, and for heat dissipation, a space enclosed by the housing and the circuit board 11 is usually filled with a heat-conducting glue in a molten state and solidified to form a heat-conducting member, and the heat-conducting member contacts with the primary winding 12 and the first secondary winding 13 and the second secondary winding 14, so that the heat generated on the primary winding 12 and the secondary winding is conducted to the second secondary winding 14 through the heat-conducting member and is conducted to the housing, and then is dissipated through a heat dissipation device outside the housing. When the second secondary winding 14 is in a sheet shape, the sheet-shaped structure makes the heat conductive glue in a molten state not easily enter between the second secondary winding 14 and the primary winding 12 or between the second secondary winding 14 and the first secondary winding 13, so that the heat resistance between the two is increased, and the heat dissipation of the primary winding 12 and the first secondary winding 13 is not facilitated. The split structure splits the cross section of the second secondary winding 14 perpendicular to the current flow direction, so that the second secondary winding 14 is provided with a hole, when the heat conducting glue in a molten state is poured, the heat conducting glue can enter between the second secondary winding 14 and the primary winding 12 or between the second secondary winding 14 and the first secondary winding 13 through the hole, so that the heat conducting glue is fully contacted with the primary winding 12 or the first secondary winding 13, heat on the primary winding 12 and the first secondary winding 13 can be quickly conducted to the second secondary winding 14 through the heat conducting piece, and is conducted to the heat radiating device through the shell, so that the heat resistance on a heat radiating path is reduced, and the high-frequency transformer 10 is fully radiated.

Specific structure of the dividing structure the embodiment of the present application is not limited, and those skilled in the art can specifically set the dividing structure according to practical situations, as long as the cross section of the second secondary winding 14 perpendicular to the current flow direction can be divided into a plurality of sub-planes. In addition, the skin effect concentrates the current on the surface of the conductor, wherein the thickness that the current occupies when flowing on the surface of the conductor is the skin depth, which is related to the frequency of the input signal, the permeability of the core 111, and the conductivity of the secondary winding, and the person skilled in the art can calculate the skin depth from the above parameters and set the area of each sub-face according to the skin depth.

According to the embodiment of the application, the split structure is arranged on the sheet-shaped second secondary winding 14, and divides the cross section of the second secondary perpendicular to the current flow direction into the plurality of sub-surfaces, so that the current flows along the plurality of sub-surfaces, the cross section when the current flows is reduced, the problem of large conduction resistance caused by skin effect is avoided, the conduction resistance is reduced, and the loss is further reduced.

Alternatively, as shown in fig. 1 and 2, the dividing structure includes a plurality of through holes 15 distributed on the second secondary winding 14, and at least two through holes 15 are included in a cross section perpendicular to the current flow direction to divide the cross section perpendicular to the current flow direction into a plurality of sub-faces.

The split structure includes a plurality of through holes 15, as shown in fig. 6, a cross section of the second secondary winding 14 of the plurality of through holes 15 perpendicular to the current flow direction is divided into a plurality of sub-faces, so that the current flows along the plurality of sub-faces, the cross section perpendicular to the current flow direction is reduced, the problem of impedance increase caused by skin effect is avoided, the conduction impedance is reduced, and further the loss is reduced.

The specific shape of the through holes 15 and the arrangement of the embodiments of the present application are not limited, and specifically, the shape of the through holes 15 may be hexagonal as shown in fig. 1, or circular as shown in fig. 2, or may be quadrangular, pentagonal, or semicircular, or an irregular pattern formed by curved surfaces, etc., and the shapes of the plurality of through holes 15 may be the same or different, so long as the section of the current flowing direction can be divided into a plurality of sub-planes. The plurality of through holes 15 may be arranged in a plurality of rows as shown in fig. 1 and 2, or may be randomly distributed.

In one implementation manner of the embodiment of the present application, as shown in fig. 1 and fig. 2, the plurality of through holes 15 are arranged in a plurality of rows along the current flow direction, and the through holes 15 in two adjacent rows are arranged in a staggered manner, or the plurality of through holes 15 are distributed in a determinant.

As shown in fig. 1, the through holes 15 are all hexagonal, and the through holes 15 are arranged in a plurality of rows along the current flow direction, and the through holes 15 in two adjacent rows are arranged in a staggered manner, so that the through holes 15 are all arranged in the direction perpendicular to the current flow direction, the area of the sub-surface can be further reduced, and the on-resistance is further reduced.

As shown in fig. 2, the through holes 15 are all circular, and the through holes 15 are arranged in a determinant manner, so that the through holes 15 are arranged in order, and the processing is convenient.

Alternatively, as shown in fig. 1, 2 and 3, the second secondary winding 14 is one and is wrapped around the outside of the primary winding 12.

When the high-frequency transformer 10 is applied to power equipment, the power equipment and a circuit topology structure form a power system, and a current signal of one second secondary winding 14 is connected with the topology structure signal through the circuit board 11 to realize the function of the power system, namely, the function of the second secondary winding 14 can be realized by one second secondary winding 14. The provision of the second secondary winding 14 can reduce the number of parts of the high-frequency transformer 10 and reduce the weight and cost of the high-frequency transformer 10 by ensuring the second secondary winding 14.

The second secondary winding 14 is wrapped around the outside of the primary winding 12 such that the second secondary winding 14 and the primary winding 12 are positioned in the same location in the magnetic field, facilitating control of the current in the second secondary winding 14.

In one implementation of the embodiment of the present application, as shown in fig. 3 and 4, the dividing structure includes a plurality of through slots 161 disposed along the current flow direction, and the plurality of through slots 161 divide the second secondary winding 14 into a plurality of winding bars 162.

The plurality of through slots 161 divide the second secondary winding 14 into a plurality of winding bars 162, as shown in fig. 4, the current is transmitted along the plurality of winding bars 162, and the winding bars 162 have a smaller cross-sectional area perpendicular to the current direction with respect to the sheet shape, so that the cross-sectional area of the current flowing is reduced, the cross-sectional area of the sub-surface can be fully utilized, the problem of impedance increase caused by skin effect is avoided, the on-resistance is reduced, and the loss is further reduced.

It should be noted that, the induced currents on the plurality of winding bars 162 are converged on the circuit board 11 to form the second output current, that is, the currents on the plurality of winding bars 162 are combined to be the induced current of the second secondary winding 14.

Alternatively, as shown in fig. 3 and 4, the winding bar 162 is reduced in cross section at both ends to be plug-connected with the wiring board 11.

In order to facilitate connection between the winding bar 162 and the circuit board 11, the two ends of the winding bar 162 are gradually reduced in the embodiment of the application, so that the circuit board 11 is conveniently connected in a plugging manner. In practical application, the circuit board 11 is provided with a connecting hole connected with the winding strip 162, the side wall and the outer edge of the connecting hole are provided with connecting pieces, the winding strip 162 is inserted into the connecting hole to be connected with the connecting pieces, and the connection between the winding strip 162 and the circuit board 11 is realized.

In one implementation of the embodiment of the present application, as shown in fig. 3 and 4, two adjacent winding bars 162 are connected by a connection point 163, so that the winding bars 162 are integrated.

The second secondary winding 14 includes a plurality of winding bars 162, the plurality of winding bars 162 are inconvenient to manufacture, transport and install, and in order to facilitate the manufacture and installation of the winding, the embodiment of the present application provides the connection point 163 between two adjacent winding bars 162 to connect the two adjacent winding bars 162, thereby connecting the plurality of winding bars 162 as a whole, and facilitating the manufacture, transport and installation.

In addition, the location of the connection point 163 is not limited in the embodiment of the present application, and the connection point 163 may be disposed at any position between two adjacent winding bars 162, and the connection point 163 is exemplified as being disposed at a side away from the wiring board 11. The number of the connection points 163 is not limited, and one connection point 163, two connection points 163, or even more may be provided between the adjacent two winding bars 162.

Alternatively, as shown in fig. 3 and 4, the plurality of connection points 163 are located on the same line. The plurality of connection points 163 are positioned on the same straight line, and the stability of connection of the plurality of winding bars 162 can be enhanced.

In one implementation manner of the embodiment of the present application, as shown in fig. 1, 2 and 3, the second secondary winding 14 is a copper sheet, and the copper sheet is U-shaped.

As can be seen from the foregoing, the second secondary winding 14 is used as a secondary winding and is capable of conducting heat generated in the high-frequency transformer 10, and the copper material is used as the material of the second secondary winding 14 in the embodiment of the application, because the copper material has good electrical conductivity and thermal conductivity, the good electrical conductivity is beneficial to the circulation of current in the second secondary winding 14, the good thermal conductivity is beneficial to the rapid conduction of heat through the second secondary winding 14, and the heat dissipation effect is improved.

It should be noted that, those skilled in the art may also select other materials as the material of the second secondary winding 14 according to practical situations, so long as the second secondary winding 14 has better electrical conductivity and thermal conductivity.

As shown in fig. 4, the copper sheet is U-shaped, two sides of the U-shaped opening end are connected with the circuit board 11 to form a winding with one turn number, and the U-shaped structure is matched with a square winding in the prior art, so that the installation of the second secondary winding 14 can be facilitated.

The embodiment of the application also discloses power equipment which comprises the high-frequency transformer 10. The power supply apparatus includes the same structure and advantageous effects as those of the high-frequency transformer 10 in the foregoing embodiment. The structure and advantageous effects of the high frequency transformer 10 have been described in detail in the foregoing embodiments, and will not be described in detail herein.

The embodiment of the application is not limited, and the embodiment can be applied to charging and discharging of new energy automobiles and charging and discharging of photovoltaic energy storage.

The above description is only of the preferred embodiments of the present application and is not intended to limit the present application, but various modifications and variations can be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims (10)

1. The utility model provides a high frequency transformer, its characterized in that includes the circuit board and set up in magnetic core on the circuit board, the coiling has primary winding and first secondary on the magnetic core, primary with first secondary respectively with the circuit board is connected, primary and/or first secondary still cladding has flaky second secondary outward, the both ends of second secondary respectively with the circuit board is connected, in order to form the electric current between the both ends of second secondary, be provided with the division structure on the second secondary, in order to cut apart the cross section that the second secondary perpendicular to electric current flows.

2. The high-frequency transformer according to claim 1, wherein the dividing structure includes a plurality of through holes distributed over the second secondary winding, and at least two through holes are included in a cross section perpendicular to a current flow direction to divide the cross section perpendicular to the current flow direction into a plurality of sub-faces.

3. The high-frequency transformer according to claim 2, wherein a plurality of the through holes are arranged in a plurality of rows along a current flow direction, the through holes of adjacent two rows are arranged in a staggered manner, or a plurality of the through holes are arranged in a matrix.

4. The high frequency transformer of claim 1, wherein the second secondary winding is one and is wrapped outside the primary winding.

5. The high frequency transformer of claim 1, wherein the dividing structure comprises a plurality of through slots disposed along the current flow direction, the plurality of through slots dividing the second secondary winding into a plurality of winding bars.

6. The high frequency transformer according to claim 5, wherein both ends of the winding bar are reduced in cross section to be connected with the wiring board in a plug-in manner.

7. The high frequency transformer according to claim 5, wherein adjacent two of the winding bars are connected by a connection point such that a plurality of the winding bars are integrated.

8. The high frequency transformer according to claim 7, wherein a plurality of the connection points are located on the same straight line.

9. The high frequency transformer of claim 1, wherein the second secondary winding is a copper sheet, the copper sheet being U-shaped.

10. A power supply device comprising a high frequency transformer according to any one of claims 1-9.