CN113517120B

CN113517120B - Matrix transformer and power supply using same

Info

Publication number: CN113517120B
Application number: CN202110802970.3A
Authority: CN
Inventors: 王文博
Original assignee: Beijing Tailicong Technology Co ltd
Current assignee: Beijing Tailicong Technology Co ltd
Priority date: 2021-07-15
Filing date: 2021-07-15
Publication date: 2022-03-01
Anticipated expiration: 2041-07-15
Also published as: CN113517120A

Abstract

The invention discloses a matrix transformer and a power supply using the same, wherein the matrix transformer comprises a magnetic core, a primary winding and a secondary winding, the magnetic core comprises a base, a primary magnetic pillar and a plurality of secondary magnetic pillars which are arranged on the base, and a flat plate which covers the primary magnetic pillar and the secondary magnetic pillars; the secondary magnetic columns are symmetrically distributed on the periphery of the primary magnetic column, the shortest distance size is arranged between each secondary magnetic column and the primary magnetic column, and the discrete value among the shortest distance sizes is smaller than or equal to a preset standard discrete value; the primary winding is wound on the primary magnetic pole, the secondary winding is wound on the secondary magnetic pole, and the primary magnetic pole and the primary winding are both positioned in a mutual inductance area formed by the secondary magnetic pole and the secondary winding based on mutual inductance; the matrix transformer has the advantages of high magnetic field coupling degree, good consistency and low conduction loss.

Description

Matrix transformer and power supply using same

Technical Field

The present invention relates to a transformer, and more particularly, to a matrix transformer and a power supply using the same.

Background

At present, a matrix transformer is used in a power supply with high power density to reduce winding impedance and leakage inductance of the transformer, and the matrix transformer has a reduced size due to the design of matrixing and high frequency, increases the coupling degree between windings, reduces the conduction loss of the windings, and is beneficial to improving the power density of the power supply.

The LLC topological structure circuit collocation matrix transformer is a relatively common power supply scheme in application scenes such as server power supplies, data center power supplies and the like, the application scenes such as the server power supplies, the data center power supplies and the like generally need low-voltage large-current output power supplies, and the requirement of large current means that the conduction loss of devices in the power supplies is particularly obvious. Aiming at the problem of high conduction loss, the common optimization scheme in the existing power supply is as follows: in the matrix transformer, a scheme that a primary winding is connected in series and a plurality of secondary windings are connected in parallel to output is adopted, so that the current on each winding is reduced, and the conduction loss of the device is reduced. In the existing scheme of the matrix transformer, a primary winding needs to be wound on each secondary magnetic pole in order to ensure the correct magnetic flux coupling direction, the wiring is long, the secondary winding is shielded, and a power supply needs to provide an additional through hole or buried hole on a circuit board beside the matrix transformer to be connected with a secondary winding tap extending out of a magnetic core structure. Moreover, the wiring of the primary winding exposed outside the magnetic core structure is only for realizing a correct winding direction, which is not conducive to improving the magnetic field coupling degree of the matrix transformer, and even the extra wiring and the extra via hole or buried hole connection of the primary winding bring extra conduction loss to the matrix transformer.

Disclosure of Invention

In order to improve the magnetic field coupling degree and reduce the conduction loss, the application provides a matrix transformer and a power supply using the matrix transformer.

In a first aspect, the present application provides a matrix transformer, which provides the following technical solutions:

a matrix transformer comprises a magnetic core, a primary winding and a secondary winding, wherein the magnetic core comprises a base, a primary magnetic column and a plurality of secondary magnetic columns which are arranged on the base, and a flat plate which covers the primary magnetic column and the secondary magnetic columns;

the secondary magnetic columns are symmetrically distributed on the periphery of the primary magnetic column, the shortest distance size is reserved between each secondary magnetic column and the primary magnetic column, and the discrete value among the shortest distance sizes is smaller than or equal to a preset standard discrete value;

the primary winding is wound on the primary magnetic pillar, the secondary winding is wound on the secondary magnetic pillar, the primary magnetic pillar and the primary winding are both located in a mutual inductance area formed by the secondary magnetic pillar and the secondary winding based on mutual inductance, and an overlapping area is arranged between the primary winding and the secondary winding.

According to the technical scheme, the primary side magnetic columns are arranged among the plurality of secondary side magnetic columns, the primary side winding is wound on the primary side magnetic columns, so that the primary side winding is surrounded by the plurality of secondary side magnetic columns and the secondary side winding, the secondary side magnetic columns are symmetrically distributed and positioned on the peripheral sides of the primary side magnetic columns, and the magnetic field coupling degree is higher and the consistency is better; the smaller the discrete value between the shortest distance sizes from the secondary magnetic columns to the primary magnetic column is, the higher the magnetic field coupling degree is, the better the consistency is, so that the matrix transformer has the advantages of high magnetic field coupling degree and good consistency; the primary winding only needs to be wound on the primary magnetic pole, the length of extra wiring of the primary winding is favorably reduced, the number of via holes or buried holes needed on a circuit board in the power supply is favorably reduced, further, the conduction loss is favorably reduced, the complexity of the power supply design and production process is reduced, and the production cost is saved.

Further, the plurality of shortest distances are equal in size.

Through the technical scheme, the shortest distance sizes from the secondary magnetic columns to the primary magnetic column are equal, so that the discrete value among the shortest distance sizes is minimum, the magnetic field coupling degree is highest, and the consistency is best.

Furthermore, the primary winding is provided with a plurality of layers of winding turns connected in parallel, and the winding turns of the secondary winding extend into the area between adjacent winding turns on the primary winding.

Through the technical scheme, the primary winding is provided with the multiple layers of winding turns which are connected in parallel, the conduction loss of the primary winding is favorably reduced, and the winding turns of the secondary winding extend into the winding turns of the primary winding, so that the magnetic field coupling degree of the matrix transformer is favorably improved.

Furthermore, each secondary winding comprises a first sub-winding and a second sub-winding which are arranged in series, the first sub-winding and the second sub-winding are wound on the same secondary magnetic column, and the first sub-winding and the second sub-winding are both provided with at least one winding turn;

the winding turns of the first sub-winding and the winding turns of the second sub-winding are arranged in a staggered and stacked mode and are correspondingly arranged in groups, and the winding turns of the first sub-winding are located at the upper layer of the corresponding winding turns of the second sub-winding.

Through the technical scheme, the magnetomotive force on the secondary winding is uniformly distributed, the leakage inductance of the secondary winding is reduced, and the alternating current resistance of the secondary winding is reduced.

Furthermore, the primary winding is provided with a plurality of layers of winding turns which are connected in parallel;

the first sub-winding and the second sub-winding both comprise a plurality of winding turns connected in parallel, and the winding turns positioned on the upper layer and the winding turns positioned on the lower layer in a corresponding relationship form a group of winding turns extending into a region between adjacent winding turns on the primary winding.

Through the technical scheme, the magnetomotive force is distributed more uniformly.

Furthermore, the turns of the primary winding positioned in the middle layer are sequentially attached.

Through the technical scheme, the primary winding intermediate layer is provided with the attached winding turns, so that the magnetomotive force is changed according to the section rule, and the magnetomotive force is distributed more uniformly.

Furthermore, only one of the two adjacent secondary windings is conducted at the same time, a connection point between the first sub-winding and the second sub-winding is a node of the secondary winding, the nodes between the adjacent secondary windings are located in the same layer, and the nodes located in the same layer are electrically connected through a proximity effect plate.

Through the technical scheme, in the angle of the conducted secondary winding, the proximity effect plate changes the proximity effect of the adjacent wires into the proximity effect of the adjacent planes, the area of the proximity effect is enlarged, the proximity effect loss is favorably reduced, the proximity effect loss is related to the conduction loss, the heat productivity is favorably reduced, and the temperature on the secondary winding is lower and the heat distribution is uniform.

Further, electrically connected adjacent said nodes: the adjacent effect plates are electrically connected between the turns of the secondary winding which are adjacent to the secondary winding and positioned at the upper layer, and/or the adjacent effect plates are electrically connected between the turns of the secondary winding which are adjacent to the secondary winding and positioned at the lower layer;

or, electrically connected adjacent said nodes: and the adjacent secondary winding is positioned between the turns of the upper layer and adjacent to the turns of the lower layer, the adjacent secondary winding is electrically connected with the adjacent effect plates, and the adjacent effect plates positioned on the upper layer and the adjacent effect plates positioned on the lower layer are provided with insulating partition plates.

Through the technical scheme, the concentration ratio of the current on the adjacent effect plate is higher, the area of the adjacent effect is increased, and the loss of the adjacent effect is further reduced.

Furthermore, the winding turns of the primary winding are arranged into metal foils with insulating paint on the surfaces;

and/or the winding turns of the secondary side winding are arranged into metal foil with insulating paint on the surface;

and/or the adjacent effect plate is formed by extending a metal foil with insulating paint on the surface.

Through the technical scheme, the metal foil is beneficial to reducing the conduction loss of the primary winding and the secondary winding and is also beneficial to enabling the magnetomotive force to be distributed more uniformly.

In a second aspect, the present application provides a power supply, which provides the following technical solutions:

a power supply is provided, wherein a circuit of the power supply is connected with any one of the matrix transformers.

In conclusion, the beneficial effects of the invention are as follows:

the primary side magnetic columns are arranged among the plurality of secondary side magnetic columns, the primary side winding is wound on the primary side magnetic columns, the secondary side magnetic columns are symmetrically distributed on the peripheral sides of the primary side magnetic columns, the discrete value of the shortest distance size from the plurality of secondary side magnetic columns to the primary side magnetic column is smaller than or equal to a preset discrete value or the multiple shortest distance sizes are equal, and the magnetic field coupling degree and the consistency are high;

the primary winding only needs to be wound on the primary magnetic pole, the length of extra wiring of the primary winding is favorably reduced, the number of via holes or buried holes needed on a circuit board in a power supply is favorably reduced, and the conduction loss is favorably reduced.

Drawings

Fig. 1 is a schematic view of the overall structure of a magnetic core in a conventional matrix transformer;

FIG. 2 is a diagram of a winding route of primary and secondary windings on a magnetic core of a conventional matrix transformer;

FIG. 3 is a diagram of another winding route of primary and secondary windings on a magnetic core of a conventional matrix transformer;

fig. 4 is a top view of the winding pattern of fig. 3;

FIG. 5 is a circuit schematic of a power supply employing matrix transformers;

FIG. 6 is a current flow diagram of the upper secondary winding conducting when the prior matrix transformer works;

FIG. 7 is a current flow diagram of the lower secondary winding not conducting when the prior matrix transformer is in operation;

FIG. 8 is a schematic diagram of the overall structure of a magnetic core in accordance with an embodiment of the present invention;

FIG. 9 is a diagram of a winding route of a primary winding and a secondary winding on a core according to an embodiment of the present application;

fig. 10 is a schematic overall structure diagram of a matrix transformer in an embodiment of the present application;

fig. 11 is a current flow diagram of an upper secondary winding when the matrix transformer operates according to an embodiment of the present application;

fig. 12 is a current flow diagram of the secondary winding of the lower layer when the matrix transformer operates according to the first embodiment of the present application;

FIG. 13 is a magnetomotive force distribution diagram of a matrix transformer in operation according to an embodiment of the present application;

fig. 14 is an exploded view of the first and second sub-windings according to the first embodiment of the present disclosure;

FIG. 15 is a schematic view of an exploded structure with a spacer in accordance with an embodiment of the present invention;

FIG. 16 shows a magnetic core structure according to the second embodiment of the present application;

fig. 17 shows a flat plate structure according to the second embodiment of the present application.

Reference numerals: 100. a magnetic core; 101. a base; 102. a secondary side magnetic column; 103. a flat plate; 104. a primary side magnetic pole; 105. separating seats; 200. a secondary winding; 201. a first sub-winding group; 202. a second shunt winding; 203. an adjacent effect plate; 204. a partition plate; 300. a primary winding.

Detailed Description

The invention is described in detail below with reference to the figures and examples.

Fig. 1 shows a magnetic core 100 in a conventional matrix transformer, where the magnetic core 100 includes a base 101 having a rectangular shape with rounded corners, cylindrical secondary legs 102 are disposed at four corners of the base 101, the magnetic core 100 further includes a plate 103 covering and press-contacting the secondary legs 102, and the structure of the plate 103 is the same as that of the base 101.

Fig. 2 is a winding route of a primary winding 300 and a secondary winding 200 on a magnetic core 100 of a conventional matrix transformer, fig. 3 is another winding route of the primary winding 300 and the secondary winding 200 on the magnetic core 100 of the conventional matrix transformer, and fig. 2 and 3 show a magnetic circuit in a secondary leg 102. The secondary windings 200 are wound on the curved surface of the secondary magnetic pillar 102, and the winding direction of each secondary winding 200 is the same. As shown in fig. 3 and 4, in order to ensure a correct magnetic flux coupling direction, the primary winding 300 needs to bypass each secondary magnetic pillar 102, the primary winding 300 has long wires, and a large part of the wires of the primary winding 300 are exposed outside the area covered by the base 101 and the flat plate 103, which is not conducive to improving the magnetic field coupling degree of the matrix transformer, and the part of the wires also bring extra conduction loss to the existing matrix transformer; secondly, additional vias or buried vias are required to connect, increasing production costs.

Fig. 5 is a schematic circuit diagram of a power supply to which a matrix transformer is applied, in which a synchronous rectifier SR1, a synchronous rectifier SR2, a synchronous rectifier SR3, a synchronous rectifier SR4, a synchronous rectifier SR5, a synchronous rectifier SR6, a synchronous rectifier SR7, and a synchronous rectifier SR8 are connected to the secondary winding 200 to control the on/off state of a circuit in which the secondary winding 200 is located. The synchronous rectifier tube can adopt a power MOSFET with extremely low on-state resistance, and the synchronous rectification is a technology of using the power MOSFET with extremely low on-state resistance to replace a rectifier diode so as to reduce rectification loss, so that the efficiency of a power supply can be greatly improved, and dead zone voltage caused by Schottky barrier voltage does not exist.

Fig. 6 and 7 are current flow diagrams of the secondary winding 200 in the operation of the conventional matrix transformer. Each secondary winding 200 of the existing matrix transformer is provided with two sections of branch windings connected in series, the two sections of branch windings are arranged in an up-down layered mode, and the winding turns of the two sections of branch windings are not distributed in a staggered and laminated mode, so that when the matrix transformer works, the secondary windings 200 which are conducted or not conducted at the same time in the matrix transformer are located in the same layer. In fig. 6, the secondary winding 200 of the conventional matrix transformer includes a synchronous rectifier SR1, a synchronous rectifier SR3, a synchronous rectifier SR5, and a synchronous rectifier SR7 on an upper layer, the synchronous rectifier SR1 is opposite to the synchronous rectifier SR3, the synchronous rectifier SR5 is simultaneously conducted to the synchronous rectifier SR7, the synchronous rectifier SR1 and the synchronous rectifier SR3 have opposite current flows, the synchronous rectifier SR5 and the synchronous rectifier SR7 have opposite current flows, according to the right-hand ampere rule, magnetic fluxes on adjacent secondary windings 200 are superposed, the current density exhibits a dense middle and sparse two sides, the current on the turns in the dense region is large and the impedance is high, so that the conduction loss of the secondary winding 200 is also high, and at this time, the conduction loss is related to the proximity effect loss. In fig. 7, in the secondary winding 200 of the conventional matrix transformer, the synchronous rectifier SR2, the synchronous rectifier SR4, the synchronous rectifier SR6, and the synchronous rectifier SR8 are placed in the lower layer, and the synchronous rectifier SR2, the synchronous rectifier SR4, the synchronous rectifier SR6, and the synchronous rectifier SR8 are not turned on.

The first embodiment is as follows:

a matrix transformer, as shown in fig. 8, includes a magnetic core 100, the external shape of the magnetic core 100 is EI type, the magnetic core 100 includes a base 101 with a rounded rectangular shape, a primary leg 104 disposed at the middle of the base 101, a plurality of secondary legs 102 disposed at the periphery of the primary leg 104, and a flat plate 103 covering the primary leg 104 and the secondary legs 102. The base 101 may also be in other shapes such as a circle, the primary magnetic pillar 104 may be in the shape of a rectangular parallelepiped, a cylinder with an elliptical horizontal cross-section, or the like, and the secondary magnetic pillar 102 may be in the shape of a cylinder, a cuboid, or the like. The secondary side magnetic pillars 102 may be located at the corners of the base 101 to facilitate reducing the volume of the matrix transformer, or may not be located at the corners of the base 101. The number of the secondary magnetic columns 102 can be odd or even, and if the number is even, the current of the matrix transformer during operation is more balanced. As shown in fig. 9, the primary leg 104 is wound with a primary winding 300, the secondary leg 102 is wound with a secondary winding 200, and the primary winding 300 and the secondary winding 200 may be wound in the same or different directions. The primary magnetic pillar 104 and the primary winding 300 are both located in a mutual inductance area formed by the secondary magnetic pillar 102 and the secondary winding 200 based on mutual inductance, an overlapping area is arranged between the primary winding 300 and the secondary winding 200, the primary winding 300 and the secondary winding 200 form strong magnetic field coupling through the overlapping area, and if the primary winding 300 and the secondary winding 200 do not form weak magnetic field coupling. Optimally, the primary winding 300 and each secondary winding 200 have overlapping areas, and the magnetic field coupling effect of the matrix transformer is more balanced if each overlapping area is the same. The plurality of secondary windings 200 may have the same structure, or may have different numbers of turns or different winding directions, in this embodiment, the same structure of the plurality of secondary windings 200 is taken as an example, and the same structure of the plurality of secondary windings 200 is beneficial to equalizing the current when the matrix transformer works. In the present application, the primary winding 300 does not need to bypass the secondary leg 102, the line of the primary winding 300 is greatly shortened, and most of the primary winding 300 is wrapped by the magnetic core 100, so that the magnetic field coupling degree is high. The primary winding 300 does not shield the secondary winding 200, an extra or special winding tap or winding joint is not needed on the secondary winding 200, for a circuit board electrically connected with the matrix transformer, a via hole or a buried hole is not needed to be additionally arranged on the circuit board, the design complexity of the circuit board is greatly reduced, the production process complexity is reduced accordingly, and the production cost is saved.

As shown in fig. 9, in this embodiment of the present application, the primary magnetic pillar 104 is a rectangular parallelepiped, the secondary magnetic pillar 102 is a cylinder, the plurality of secondary magnetic pillars 102 are symmetrically distributed on the base 101, the secondary magnetic pillars 102 are located on the side surface of the base 101 near four corners thereof, two secondary magnetic pillars 102 are respectively distributed on two sides of the primary magnetic pillar 104 in the length direction, only one of the two adjacent secondary windings 200 located on the same side of the primary magnetic pillar 104 in the length direction is turned on at the same time, or only one of the two adjacent secondary windings 200 arranged in the width direction of the primary magnetic pillar 104 is turned on at the same time, and only one of the two adjacent secondary windings 200 located on the same side of the primary magnetic pillar 104 in the length direction is turned on at the same time. Each secondary magnetic pole 102 and the primary magnetic pole 104 have a shortest distance dimension, a discrete value between the shortest distance dimensions is less than or equal to a preset standard discrete value, a variance calculation formula can be adopted as a calculation method of the discrete value, the standard discrete value is 0 or a number greater than 0, and the smaller the standard discrete value is, the higher the magnetic field coupling degree is. Optimally, the discrete value between the plurality of shortest distance dimensions is 0, i.e., the shortest distance dimensions from the plurality of secondary legs 102 to the primary leg 104 are all equal. The discrete value among the plurality of shortest distance sizes is the smallest, the magnetic field coupling degree can reach the highest, and the current equalization, namely the consistency, of the secondary windings 200 on the secondary magnetic columns 102 is the best. The magnetic paths in the primary leg 104 and the secondary leg 102 are shown in fig. 9. In the topological structure of the LLC resonant circuit, the leakage inductance of the primary winding 300 and the secondary winding 200 can be adjusted by changing the distance from the primary leg 104 to the secondary leg 102, which serves as the internal resonant inductance, to meet the resonant frequency requirement of the LLC resonant circuit.

The primary winding 300 has one or more turns, and the turn-on loss of the multi-turn parallel connection is lower than that of the one turn. As shown in fig. 10, the primary winding 300 has multiple layers of parallel turns, each layer of the parallel turns is wound around the primary magnetic pole 104, and the turns of the secondary winding 200 extend into the area between adjacent turns on the primary winding 300, which is beneficial to reducing the conduction loss of the primary winding 300. The winding turns of the primary winding 300 are made of metal foil with insulating paint on the surface, the metal foil is flat and is flatly laid in the magnetic core 100, and the metal foil can be made of copper foil, silver foil or other metal materials. The turns of the secondary winding 200 may also be provided as a metal foil with an insulating varnish on the surface. Compared with an enameled wire which is commonly used as a winding, the metal foil is beneficial to reducing conduction loss of the primary winding 300 and the secondary winding 200, and the secondary winding 200 extends into the primary winding 300 and is also beneficial to enabling magnetomotive force of the primary winding 300 and magnetomotive force of the secondary winding 200 to be distributed more uniformly.

As shown in fig. 11 and 12, the secondary winding 200 is also connected to the synchronous rectifier SR1, the synchronous rectifier SR2, the synchronous rectifier SR3, the synchronous rectifier SR4, the synchronous rectifier SR5, the synchronous rectifier SR6, the synchronous rectifier SR7, and the synchronous rectifier SR8, and the secondary winding 200 connected to the synchronous rectifier SR1, the synchronous rectifier SR4, the synchronous rectifier SR5, and the synchronous rectifier SR8 is wound on the upper layer, and the secondary winding 200 connected to the synchronous rectifier SR2, the synchronous rectifier SR3, the synchronous rectifier SR6, and the synchronous rectifier SR7 is wound on the lower layer. In the same layer at the same time, only one of the two adjacent secondary windings 200 is conducted, so that the secondary windings 200 in different conduction states are arranged in a staggered manner.

Each secondary winding 200 comprises a first sub-winding 201 and a second sub-winding 202 which are arranged in series, the first sub-winding 201 and the second sub-winding 202 are wound on the same secondary magnetic pole 102, and the winding direction of the first sub-winding 201 and the winding direction of the second sub-winding 202 can be the same or different. In the secondary winding 200 in which the synchronous rectifier SR1 is connected to the synchronous rectifier SR2, the synchronous rectifier SR1 is electrically connected in series to the first sub-winding 201, and the synchronous rectifier SR2 is electrically connected in series to the second sub-winding 202.

As shown in fig. 10, in each secondary winding 200, the first sub-winding 201 and the second sub-winding 202 are provided with at least one turn, and the conduction loss after the multiple turns are connected in parallel is lower than that of one turn. When the first sub-winding 201 and/or the second sub-winding 202 are provided with one turn, the turn of the first sub-winding 201 is pressed on the turn of the second sub-winding 202, that is, the turn of the first sub-winding 201 is located at an upper position of the turn of the second sub-winding 202, and the turn of the second sub-winding 202 is located at a lower position of the turn of the first sub-winding 201. The turns of the first sub-winding 201 and the turns of the second sub-winding 202 are alternately stacked. The corresponding relationship between the turns of the first sub-winding 201 and the turns of the second sub-winding 202 may be that the turns of one first sub-winding 201 correspond to the turns of one second sub-winding 202, the turns of one first sub-winding 201 correspond to the turns of a plurality of second sub-windings 202, the turns of a plurality of first sub-windings 201 correspond to the turns of one second sub-winding 202, and/or the turns of a plurality of first sub-windings 201 correspond to the turns of a plurality of second sub-windings 202, for example, the turns of one first sub-winding 201 correspond to the turns of one second sub-winding 202 in this embodiment. The staggered and laminated arrangement of the winding turns is favorable for uniformly distributing the magnetomotive force on the secondary winding 200, reducing the leakage inductance of the secondary winding 200 and reducing the alternating current resistance of the secondary winding 200.

The turns on the upper layer and the turns on the lower layer in corresponding relation form a set of regions extending between adjacent turns on the primary winding 300, forming an overlap region. If the primary winding 300 has only one turn, the turn extends between the turns of the secondary winding 200 to form an overlap region. An insulating layer can be arranged between every two turns, and the insulating layer can be made of insulating films or insulating paint. The turns of the primary winding 300 positioned in the middle layer are sequentially attached, the middle layer of the primary winding 300 is provided with the attached turns, so that the magnetomotive force of the matrix transformer is changed in a section rule, and the number of the attached turns is two or more than two, so that the magnetomotive force on the primary winding 300 is compensated, and the magnetomotive force of the matrix transformer is distributed more uniformly. As shown in fig. 10 and 13, the turns of the primary winding 300 and the secondary winding 200 may both be made of copper foil, and the primary winding 300 has six layers of copper foil connected in parallel to reduce the conduction loss of the primary winding 300. The secondary winding 200 has eight layers of copper foil, and the eight layers of copper foil are divided into four pairs of turns, and the four pairs of turns are arranged in a manner that two layers of turns are staggered and stacked. The turns of the corresponding layer of the four pairs of turns are connected in parallel to reduce the impedance of the secondary winding 200, i.e., the upper four turns are connected in parallel and the lower four turns are connected in parallel. The primary winding 300 and the secondary winding 200 have fourteen layers of copper foil in total.

The distribution of magnetomotive forces during operation of the matrix transformer is shown in fig. 13, where P represents the turns of a primary winding 300 and the numbers represent the number of turns. For example, P1 represents the first, and also the uppermost, turn of the primary winding 300, the primary winding 300 having the following turns: p1, P2, P3, P4, P5 and P6, wherein the P3 is jointed with the P4, and no winding turns of the secondary winding 200 extend between the P3 and the P4. Insulator stands for insulating layer and can be an insulating paint coating, an insulating film or an insulating board. S represents the turns of a secondary winding 200, the first number 1 after S represents the upper layer, the first number 2 after S represents the lower layer, and the second number after S represents the number of groups. For example, S11 represents a first set of upper layer turns of the secondary winding 200. S21 represents a first set of lower layer turns of the secondary winding 200; s14 represents the fourth set of upper layer turns of the secondary winding 200, and so on.

As shown in fig. 11, the two secondary windings 200 that are adjacent to each other and located on the same side in the length direction of the primary leg 104 are only turned on one at the same time, and although the primary leg 104 separates the two secondary windings 200 that are simultaneously turned on, the thickness of the primary leg 104 is thin, the linear distance between the two secondary windings 200 that are simultaneously turned on does not change greatly, the two secondary windings 200 that are simultaneously turned on are equivalent to the proximity effect of adjacent wires, the proximity effect loss is only reduced a little, and the current distribution of the two secondary windings 200 is still uneven and concentrated in the middle position.

As shown in fig. 14, a connection point between the first shunt winding 201 and the second shunt winding 202 is a node of the secondary winding 200, i.e., a middle tap of the secondary winding 200. The nodes between two adjacent secondary windings 200 which are positioned on the same side of the primary magnetic pole 104 in the length direction are positioned on the same layer, and the nodes positioned on the same layer are electrically connected through the adjacent effect plate 203, and the adjacent effect plate 203 is electrically connected on the turn of the two adjacent secondary windings 200 on the same layer. In fig. 14, the turns in the first sub-winding 201 are all connected in parallel, and the turns in the second sub-winding 202 are also all connected in parallel, so that each secondary winding 200 has multiple layers of nodes. Fig. 14 shows that the adjacent effect plate 203 is electrically connected to the turn of the adjacent two secondary windings 200 at the lower position, and the node on the turn at the upper position is far away from the adjacent secondary winding 200, at this time, the adjacent effect plate 203 cannot be electrically connected between the ends of the adjacent turns at the upper position of the adjacent two secondary windings 200, otherwise the plurality of synchronous rectifiers connected to the adjacent two secondary windings 200 are short-circuited to affect the output current of the matrix transformer.

As shown in fig. 15, there are two adjacent secondary windings 200 located on the same side of the primary magnetic pillar 104 in the length direction, and the node of the upper layer winding and the node of the lower layer winding are both located between the two adjacent secondary windings 200. Adjacent effect plates 203 can be electrically connected between turns of adjacent secondary windings 200 located on the upper layer and between turns of adjacent secondary windings 200 located on the lower layer, at this time, an insulating partition plate 204 can be arranged between the adjacent effect plates 203 located on the upper layer and the adjacent effect plates 203 located on the lower layer, and the insulating thin PCB or insulating soft film can be adopted as the partition plate 204, so that the difficulty of current breakdown between the adjacent nearest adjacent effect plates 203 is improved.

The nodes between adjacent secondary windings 200 are located in the same layer, and the nodes located in the same layer and the adjacent effect plate 203 can be welded by metal foil or integrally formed copper foil. After the adjacent effect plate 203 is arranged, when the matrix transformer works, current is concentrated on the surface of the copper foil, but the current is equally divided to the plane of the electrically connected copper foil due to the large area of the copper foil, the temperature of the copper foil is low, and the heat distribution is even. The proximity effect plate 203 changes the proximity effect of the adjacent wire into the proximity effect of the adjacent plane, the concentration of the current on the proximity effect plate 203 is higher, the area of the proximity effect is enlarged, the proximity effect loss is favorably reduced, even the effect of almost no proximity effect loss is achieved, the heat productivity of the secondary winding 200 is reduced, and the temperature on the secondary winding 200 is lower and the heat distribution is uniform.

The core 100 of the present embodiment has a significant reduction in loss at the angle of the magnetic flux distribution in the core 100. At the heat dissipation angle of the magnetic core 100, although the primary magnetic pole 104 is additionally added in the present application, the matrix transformer adopts the high-frequency magnetic core 100, and when the matrix transformer is in a high-frequency working state, the working frequency can be increased to 1MHz, the loss of the magnetic core 100 is low, and the overall heat dissipation effect of the magnetic core 100 is also increased. On the premise that the loss of the magnetic core 100 is low and the conduction loss of the primary winding 300 and the secondary winding 200 is low, the size of the rectangular transformer is greatly reduced, and the power density of the rectangular transformer is improved.

Example two:

a matrix transformer, as shown in fig. 16 and 17, the difference from the first embodiment is that a plurality of sub-seats 105 extending outward are disposed on the side of a base 101, and the sub-seats 105 are uniformly distributed around the base 101. The primary side magnetic pillar 104 is arranged on the base 101, the secondary side magnetic pillar 102 is arranged on the sub-base 105, and the secondary side magnetic pillars 102 are evenly distributed around the primary side magnetic pillar 104. The primary magnetic pole 104 may be a cylindrical pole with a cross section in a shape of a waist circle, and the like, the primary winding 300 is wound around the primary magnetic pole 104, and the secondary winding 200 is wound around the secondary magnetic pole 102. The flat plate 103 covers the base 101, the sub-mount 105, the primary magnetic column 104 and the secondary magnetic column 102, wherein the shape of the flat plate 103 can be the same as the combined structure of the base 101 and the sub-mount 105, which is beneficial to optimizing the volume size of the matrix transformer.

Example three:

a power supply, wherein a circuit of the power supply is connected with any one of the matrix transformers described in the above embodiments.

The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may occur to those skilled in the art without departing from the principle of the invention, and are considered to be within the scope of the invention.

Claims

1. A matrix transformer comprising a magnetic core (100), a primary winding (300) and a secondary winding (200), the magnetic core (100) comprising a base (101), a primary leg (104) and a plurality of secondary legs (102) disposed on the base (101), and a plate (103) covering the primary leg (104) and the secondary legs (102), characterized in that: the secondary magnetic columns (102) are symmetrically distributed and distributed on the periphery of the primary magnetic column (104), the shortest distance size is arranged between each secondary magnetic column (102) and the primary magnetic column (104), and the discrete value between the shortest distance sizes is smaller than or equal to a preset standard discrete value;

the primary winding (300) is wound on the primary magnetic pillar (104), the secondary winding (200) is wound on the secondary magnetic pillar (102), the primary magnetic pillar (104) and the primary winding (300) are both positioned in a mutual inductance area formed by the secondary magnetic pillar (102) and the secondary winding (200) based on mutual inductance, and an overlapping area is arranged between the primary winding (300) and the secondary winding (200);

each secondary winding (200) comprises a first sub-winding (201) and a second sub-winding (202) which are arranged in series, the first sub-winding (201) and the second sub-winding (202) are wound on the same secondary magnetic pole (102), and the first sub-winding (201) and the second sub-winding (202) are both provided with at least one turn;

the turns of the first sub-winding (201) and the turns of the second sub-winding (202) are arranged in a staggered and laminated mode and are correspondingly arranged in groups, and the turns of the first sub-winding (201) are located at the upper layer position of the corresponding turns of the second sub-winding (202);

only one of the two adjacent secondary windings (200) is conducted at the same time, the connection point between the first sub-winding (201) and the second sub-winding (202) is the node of the secondary winding (200), the nodes between the adjacent secondary windings (200) are located in the same layer, and the nodes located in the same layer are electrically connected through the adjacent effect plate (203).

2. A matrix transformer according to claim 1, characterized in that: the plurality of shortest distances are equal in size.

3. A matrix transformer according to claim 1, characterized in that: the primary winding (300) is provided with a plurality of layers of winding turns which are connected in parallel, and the winding turns of the secondary winding (200) extend into the area between adjacent winding turns on the primary winding (300).

4. A matrix transformer according to claim 1, characterized in that: the primary winding (300) is provided with a plurality of layers of winding turns which are connected in parallel;

the first sub-winding (201) and the second sub-winding (202) both comprise a plurality of parallel winding turns, and the winding turns on the upper layer and the winding turns on the lower layer which are in corresponding relation form a group of winding turns extending into the area between the adjacent winding turns on the primary winding (300).

5. A matrix transformer according to claim 4, characterised in that: the turns of the primary winding (300) in the middle layer are sequentially attached.

6. A matrix transformer according to claim 1, characterized in that: electrically connected adjacent said nodes: the adjacent effect plate (203) is electrically connected between the turns of the secondary winding (200) located at the upper layer adjacent to the adjacent effect plate, and/or the adjacent effect plate (203) is electrically connected between the turns of the secondary winding (200) located at the lower layer adjacent to the adjacent effect plate;

or, electrically connected adjacent said nodes: adjacent the secondary winding (200) is located between the turn of upper strata, adjacent the secondary winding (200) is located between the turn of lower floor all be connected with adjacent effect board (203), be located the upper strata adjacent effect board (203) with be located the lower floor be provided with insulating space bar (204) between adjacent effect board (203).

7. A matrix transformer according to claim 1, characterized in that: the winding of the primary winding (300) is arranged to be a metal foil with insulating paint on the surface;

and/or the turns of the secondary winding (200) are arranged into metal foil with insulating paint on the surface;

and/or the adjacent effect plate (203) is formed by extending a metal foil with an insulating paint on the surface.

8. A power supply, characterized by: a matrix transformer as claimed in any one of claims 1 to 7 is connected in the circuit of the power supply.