WO2022088728A1 - 平面变压器、电源转换电路及适配器 - Google Patents

平面变压器、电源转换电路及适配器 Download PDF

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Publication number
WO2022088728A1
WO2022088728A1 PCT/CN2021/103099 CN2021103099W WO2022088728A1 WO 2022088728 A1 WO2022088728 A1 WO 2022088728A1 CN 2021103099 W CN2021103099 W CN 2021103099W WO 2022088728 A1 WO2022088728 A1 WO 2022088728A1
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Prior art keywords
winding
noise
winding layer
layer
primary
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PCT/CN2021/103099
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English (en)
French (fr)
Inventor
余鹏
任杰
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华为技术有限公司
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Priority to EP21884467.8A priority Critical patent/EP4213170A4/en
Publication of WO2022088728A1 publication Critical patent/WO2022088728A1/zh
Priority to US18/306,363 priority patent/US20230260694A1/en

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/44—Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/33—Arrangements for noise damping
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/24—Magnetic cores
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/28—Coils; Windings; Conductive connections
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/28—Coils; Windings; Conductive connections
    • H01F27/2804—Printed windings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/28—Coils; Windings; Conductive connections
    • H01F27/29—Terminals; Tapping arrangements for signal inductances
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/34—Special means for preventing or reducing unwanted electric or magnetic effects, e.g. no-load losses, reactive currents, harmonics, oscillations, leakage fields
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/34—Special means for preventing or reducing unwanted electric or magnetic effects, e.g. no-load losses, reactive currents, harmonics, oscillations, leakage fields
    • H01F27/38—Auxiliary core members; Auxiliary coils or windings
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/0064—Magnetic structures combining different functions, e.g. storage, filtering or transformation
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/12—Arrangements for reducing harmonics from ac input or output
    • H02M1/123—Suppression of common mode voltage or current
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/28—Coils; Windings; Conductive connections
    • H01F27/2804—Printed windings
    • H01F2027/2809—Printed windings on stacked layers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/28—Coils; Windings; Conductive connections
    • H01F27/2804—Printed windings
    • H01F2027/2819—Planar transformers with printed windings, e.g. surrounded by two cores and to be mounted on printed circuit

Definitions

  • the present application relates to the field of circuit technology, in particular to a planar transformer, a power conversion circuit and an adapter.
  • the switching power supply has developed rapidly due to its advantages of high efficiency, small size and good output stability.
  • the electromagnetic interference problem during the working process of the switching power supply is very prominent.
  • the electromagnetic interference of the switching power supply mainly comes from the external interference source, the turn-off and conduction of its own switching device, the direction recovery of the rectifier diode, and the noise generated by the capacitor/inductor/wire. These noise signals will be conducted and radiated along the circuit network to the electrical equipment. , causing electromagnetic interference. Therefore, switching power supply has very strict requirements on noise suppression.
  • the noise of the switching power supply is divided into differential mode noise and common mode noise.
  • the differential mode noise mainly includes the noise caused by the pulsating current of the switching converter.
  • Common mode noise mainly includes the noise between the reference ground caused by the interaction between the parameters of the switching power supply circuit. In practical engineering applications, common mode noise is often the main factor leading to electromagnetic interference. Therefore, how to reduce or even eliminate the common mode noise of the switching power supply is a very concerned issue in the industry.
  • the present application provides a planar transformer, a power conversion circuit and an adapter, which can improve the performance of noise suppression.
  • the present application provides a planar transformer, comprising a magnetic core and a printed circuit board (PCB) winding board, wherein the PCB winding board includes: a primary winding, a secondary winding and a first noise cancelling winding.
  • PCB printed circuit board
  • the primary winding includes a first primary winding layer
  • the secondary winding includes a first secondary winding layer
  • the first noise canceling winding includes at least two noise canceling winding layers
  • the at least two noise canceling layers The coils of the noise canceling winding in the winding layer are connected in series to form the first noise canceling winding;
  • the first end of the first noise canceling winding is used to connect to the potential dead point of the secondary circuit of the power conversion circuit or to connect The potential quiescent point of the primary circuit of the power conversion circuit, the second end of the first noise canceling winding is floating;
  • the noise canceling winding layer where the second end of the first noise canceling winding is located is the first a noise canceling winding layer,
  • the first noise canceling winding layer is disposed between the first primary winding layer and the first secondary winding layer, and when the first end of the first noise canceling winding is used for When connecting the potential dead point of the secondary circuit, the first noise canceling winding layer is adjacent to the first primary winding layer
  • the first noise canceling winding is arranged between the primary winding and the secondary winding of the planar transformer, and the number of coil turns of each noise canceling winding layer in the first noise canceling winding is designed, so that the When the planar transformer works, the induced voltage of the noise cancellation winding coil in the first noise cancellation winding layer can be used to cancel or compensate the induced voltage of the first secondary winding layer, so as to suppress the common mode generated by the secondary winding or the primary winding noise, thereby improving the performance of noise suppression.
  • the first noise canceling winding is formed by the coils of the noise canceling winding in at least two noise canceling winding layers in series
  • the first noise canceling layer disposed between the first primary winding layer and the first secondary winding layer is the noise-cancelling winding layer where the second end of the first noise-cancelling winding is located, so that the noise-cancelling winding coils of other noise-cancelling winding layers in the first noise-cancelling winding connected in series with the first noise-cancelling winding layer are used to
  • the induced voltage of the noise cancellation winding coil in the first noise winding layer is increased, so compared with the prior art, the first noise winding layer in the present application can achieve the required induced voltage with fewer coil turns.
  • only one noise cancellation winding layer may be provided between the first primary winding layer and the first secondary winding layer, or two or more layers of noise cancellation winding layers may be provided, which is not limited herein.
  • the first noise canceling winding layer is disposed between the first primary winding layer and the first secondary winding layer, and when the first end of the first noise canceling winding is used to connect the potential dead point of the secondary circuit, the first A noise canceling winding layer is adjacent to the first primary winding layer.
  • the first noise canceling winding layer is in phase with the first secondary winding layer. Neighbors can be.
  • the primary winding may further include a second primary winding layer; the secondary winding may further include a second secondary winding layer; between the second primary winding layer and the second secondary winding layer There is also at least one second noise canceling winding layer disposed therebetween, wherein the second noise canceling winding layer refers to other noise canceling layers in the first noise canceling winding except the first noise canceling winding layer winding layer. That is, the induced voltage of the cancellation winding coil in the second noise cancellation winding layer is used to cancel or compensate the induced voltage of the second secondary winding layer, so as to further suppress the common mode noise generated by the secondary winding or the primary winding, thereby improving the noise suppression effect. performance.
  • the second noise cancellation winding layer where the noise cancellation winding farthest from the first end is located is disposed on the second primary winding layer and the second secondary winding layer between and adjacent to the second primary winding layer and the second secondary winding layer respectively.
  • the second noise-cancelling winding layer where the noise-cancelling winding farthest from the first end is located and the noise-cancelling winding layer in the second noise-cancelling winding layer
  • the induced voltage of the winding is relatively the largest, so if the same induced voltage needs to be generated, the number of turns of the coil set in the second noise cancellation winding layer where the noise cancellation winding farthest from the first end is located can be the smallest.
  • the second noise canceling winding layer where the first end is located may be arranged between the second primary winding layer and the between the second secondary winding layers and adjacent to the second primary winding layer and the second secondary winding layer respectively.
  • the coil turn width of the noise cancellation winding in the first noise cancellation winding layer is larger than the coil turn width of the noise cancellation winding in the second noise cancellation winding layer. That is, the turn width of the coil in the noise-cancelling winding layer where the second end of the first noise-cancelling winding is located is designed to be wider. In contrast, the coil in the noise-cancelling winding layer where the first end of the first noise-cancelling winding is located is designed to be wider. The turn width is designed to be narrower. This can further reduce the number of turns of the first noise cancelling winding.
  • the coil turn widths of the noise cancellation windings in the first noise cancellation winding layer are the same.
  • the coil of the noise canceling winding that is closer to the second end has a larger turn width of the coil.
  • the PCB winding board further includes auxiliary windings, and the auxiliary windings are disposed in at least one layer of the second noise canceling winding layer.
  • the second noise canceling winding layer is mainly used to increase the induced voltage of the coil in the first noise canceling winding layer, disposing the auxiliary winding in the second noise canceling winding layer will not affect the first noise canceling winding layer.
  • the number of winding layers in the PCB winding board can be reduced, the space utilization rate of the planar transformer can be improved, and the cost of the planar transformer can be saved.
  • the auxiliary winding may be any other type of winding except the noise cancellation winding, which is not limited herein.
  • the relative positions of the primary winding and the secondary winding may include at least the following three ways.
  • all the primary winding layers included in the primary winding may be located on one side of all the secondary winding layers included in the secondary winding.
  • the secondary windings can be arranged on both sides of the primary winding, i.e., a part of the secondary winding layer in the secondary winding is arranged on one side of the primary winding and the other part of the secondary winding is arranged on one side of the primary winding.
  • the secondary winding layer is arranged on the other side of the primary winding, forming a sandwich structure similar to a "sandwich". Using the above-mentioned "sandwich" structure can reduce the high frequency eddy current loss and leakage inductance of the winding.
  • the primary winding can also be arranged on both sides of the secondary winding.
  • a power conversion circuit provided by the present application includes: a primary circuit, a secondary circuit, and any one of the planar transformers in the first aspect, wherein the planar transformer is provided between the primary circuit and the secondary circuit. between.
  • an adapter provided by the present application includes a casing and the power conversion circuit described in the second aspect, wherein the power conversion circuit is arranged in the casing.
  • FIG. 1 is a schematic diagram of a possible application scenario provided by an embodiment of the present application
  • FIG. 2 is a schematic diagram of a power conversion circuit provided by an embodiment of the present application.
  • FIG. 3 is a schematic diagram of a power conversion circuit provided by another embodiment of the present application.
  • FIG. 4 is a schematic diagram of a noise suppression method according to an embodiment of the present application.
  • FIG. 5 is a schematic cross-sectional view of a planar transformer provided in the related art
  • FIG. 6 is a schematic structural diagram of a planar transformer according to an embodiment of the present application.
  • FIG. 7 is a schematic cross-sectional view of a planar transformer according to another embodiment of the present application.
  • FIG. 8 is a schematic cross-sectional view of a planar transformer according to another embodiment of the present application.
  • FIG. 9 is a schematic cross-sectional view of a planar transformer according to another embodiment of the present application.
  • FIG. 10 is a schematic cross-sectional view of a planar transformer according to another embodiment of the present application.
  • FIG. 11 is a schematic cross-sectional view of a planar transformer according to another embodiment of the present application.
  • FIG. 12 is a schematic cross-sectional view of a planar transformer according to another embodiment of the present application.
  • FIG. 13 is a schematic cross-sectional view of a planar transformer according to another embodiment of the present application.
  • FIG. 14 is a schematic cross-sectional view of a planar transformer according to another embodiment of the present application.
  • 15 is a schematic diagram of a connection relationship between a power conversion circuit and a planar transformer according to an embodiment of the present application
  • FIG. 16 is a schematic structural diagram of an adapter provided by an embodiment of the present application.
  • Planar transformer Different from the traditional transformer structure, the magnetic core and winding of the planar transformer are planar structures. Magnetic cores generally use small-sized E-type and RM-type magnetic core structures, and windings are generally made of multilayer printed circuit boards (PCBs). This design has lower DC resistance and smaller leakage. Inductance and distributed capacitance, the height is very small, and it can have a higher operating frequency.
  • PCBs printed circuit boards
  • Flyback converter widely used in AC/DC (AC/DC) and DC/DC (DC/DC) conversion, is a relatively common low-power switching power converter, with the advantages of simple structure and low cost .
  • Its core components include power switch tubes, transformers, diodes and capacitors.
  • the power switch tube is controlled by pulse width modulation, which generates a high-frequency square wave signal in the primary coil of the transformer by closing and conducting, and then inductively couples to the secondary coil of the transformer to realize the transfer of energy.
  • pulse width modulation which generates a high-frequency square wave signal in the primary coil of the transformer by closing and conducting, and then inductively couples to the secondary coil of the transformer to realize the transfer of energy.
  • Common mode noise also known as asymmetric noise or line-to-ground noise, exists in electrical equipment that uses AC power. The current of common mode noise flows in the same direction on two power lines and The phase to ground remains the same and returns through the ground wire.
  • the voltage potential amplitude on the network node remains relatively constant during the circuit operation process, without high-frequency jumps or oscillations.
  • the filter capacitor after rectification by the primary side circuit of the flyback converter and the filter capacitor after rectification by the secondary side circuit are the potential dead points.
  • Winding layers In planar transformers, winding layers refer to the multi-turn coils that lie in the same plane in the winding. The plane is perpendicular to the central axis of the magnetic core around which the windings surround, and the multi-turn coils can be wound in parallel on the same plane from the inside to the outside or from the outside to the inside. In a winding, there may be multiple winding layers, and the planes of each winding layer are parallel to each other and are arranged perpendicular to the central axis of the magnetic core.
  • two adjacent winding layers refer to two winding layers in which the planes of the two winding layers are parallel, and there is no other winding layer in the middle.
  • the present application provides a planar transformer, a power conversion circuit and an adapter.
  • the above-mentioned planar transformer can be arranged in a power conversion circuit
  • the above-mentioned power conversion circuit can be arranged in an adapter.
  • the adapter can be applied to the scenario of charging or powering the device.
  • FIG. 1 shows a possible application scenario of the embodiment of the present application.
  • the application scenario includes an external power supply 11 , an adapter 12 and a device to be charged 13 .
  • the above-mentioned device 13 to be charged may include a cellular phone, a notebook computer, a battery, etc., which is not limited in this embodiment of the present application.
  • the adapter 12 can be connected to the external power source 11, and the power conversion circuit included in the adapter 12 is used to convert the higher voltage provided by the external power source 11 into a lower voltage that meets the charging or power supply standard of the device to be charged 13, and provides the power supply for the device to be charged 13.
  • the charging device 13 performs charging or power supply.
  • the planar transformer provided by the embodiments of the present application can reduce noise generated during operation.
  • the above noise may include common mode noise.
  • the above-mentioned power conversion circuit may be a switching power converter, for example, the switching power converter may include the above-mentioned flyback converter.
  • Common mode noise is mainly generated by the interaction between parameters of the switching power supply circuit to the reference ground. The following describes the mechanism of common mode noise generation and transmission in the power conversion circuit 20 with reference to FIG. 2 and FIG. 3 .
  • the power conversion circuit 20 generally includes a primary circuit 21 , a secondary circuit 22 and a transformer 23 .
  • the primary circuit generally includes a primary switch tube 211 and a primary filter capacitor 212 . Further, the primary circuit also includes a rectifier circuit.
  • the above-mentioned primary switch tube 211 may also be referred to as a power switch tube.
  • the secondary circuit 22 generally includes a secondary rectifier tube 221 and a secondary filter capacitor 222 .
  • the transformer 23 includes a primary winding 231 , a magnetic core, and a secondary winding 232 .
  • the primary winding 231 can be connected to the primary switch tube 211 and the primary filter capacitor 212
  • the secondary winding 232 can be connected to the secondary rectifier tube 221 and the secondary filter capacitor 222 .
  • the primary filter capacitor 212 and the secondary filter capacitor 222 are usually electrolytic capacitors.
  • the node connected to any one of the two ends of the primary filter capacitor 212 is the potential dead point of the primary circuit, or the ground node of the primary circuit may also be the potential dead point of the primary circuit.
  • the node connected to any one of the two ends of the secondary filter capacitor 222 is the potential dead point of the secondary circuit.
  • the AC power input from the external power source 11 is rectified and filtered by the primary circuit 21 , and then converted into a stable high-voltage DC power and input to the primary winding 231 of the transformer 23 .
  • the primary switch tube 211 connected to the primary winding 231 is turned on and off at high frequency to couple the voltage on the primary winding 231 to the secondary winding 232 .
  • a low-voltage direct current is output to the load to charge or power the load.
  • the above-mentioned load is the above-mentioned device to be charged 13 .
  • the primary switch 211 generates a jump voltage Vp due to the high frequency on and off
  • the secondary rectifier 221 generates a jump voltage due to the high frequency on and off Vs.
  • the jump voltages Vp and Vs Due to the parasitic capacitance between the primary winding 231 and the secondary winding 232 of the transformer, the jump voltages Vp and Vs generate common mode noise in the power conversion circuit 20 through the parasitic capacitance described above.
  • the above-mentioned parasitic capacitance includes the distributed capacitance Cps between the primary winding and the secondary winding and the distributed capacitance Csp between the secondary winding and the primary winding.
  • the jump voltage Vp in the primary circuit generates a noise current Ips flowing to the ground through Cps
  • the jump voltage Vs in the secondary circuit generates a noise current Isp flowing to the ground through Csp.
  • the above-mentioned noise current Ips and noise current Isp are common mode noise.
  • Figure 3 also shows the Line Impedance Stabilization Network (LISN) circuit.
  • the LISN circuit is a test circuit used to detect the common mode noise current flowing into the ground when the power conversion circuit is working. In other words, it can be considered that the ground current detected by the LISN network is equivalent to the common mode noise generated by the power conversion circuit.
  • FIG. 4 is a schematic diagram of a method for suppressing noise in the related art.
  • a noise canceling winding 233 is introduced into the planar transformer 23 to generate a reverse noise current.
  • the number of turns of the noise canceling winding 233 is adjusted to adjust the magnitude of the reverse noise current.
  • FIG. 5 is a schematic cross-sectional structure diagram of a winding in a planar transformer in the related art. As shown in FIG.
  • the noise cancellation winding layers B1 and B2 are respectively arranged between the primary winding 231 and the secondary winding 232 , and the noise cancellation winding layers B1 and B2 are respectively provided with Nb-turn noise cancellation windings 233 .
  • One end of the noise canceling winding 233 in the cancelling winding layer B1 or B2 is connected to the potential static point of the primary circuit, and the other end is floating.
  • the number of turns of the noise cancellation winding is generally larger, about more than 4 turns. Too many turns will bring the following disadvantages: (1) The width of the winding channel of the noise canceling winding layer is limited, and the maximum number of turns is limited, which may lead to insufficient reverse noise current; (2) The noise canceling winding turns and turns It is necessary to reserve a certain processing distance between them. Too many turns will cause the noise cancellation winding to shield the primary power winding incompletely, and the more turns, the worse the shielding effect; (3) The noise cancellation winding turns in the noise cancellation winding layer When the number is large, the cumulative machining tolerance is large, resulting in poor noise consistency.
  • an embodiment of the present application proposes a planar transformer with lower common mode noise.
  • a power conversion circuit using the planar transformer has higher noise suppression performance and can reduce the number of turns of the noise cancellation winding.
  • the present application also provides a power conversion circuit using the planar transformer, and an adapter using the power conversion circuit.
  • the planar transformer, the power conversion circuit, and the adapter reference may be made to the descriptions in FIG. 1 to FIG. 3 , which are not repeated here for brevity.
  • the transformer provided in the embodiments of the present application is mainly composed of a magnetic core and a winding coil.
  • the winding coil can be a traditional copper wire firing, or can be a PCB winding board formed by etching a multi-layer PCB.
  • the latter is generally referred to as a planar transformer because it is flatter than the former.
  • FIG. 6 shows a schematic structural diagram of the planar transformer 60 .
  • the planar transformer 60 includes a magnetic core 61 and a PCB winding plate 62 .
  • the embodiment of the present application does not limit the material and shape of the magnetic core 61 .
  • the shape of the magnetic core 61 may be an EE type, an EI type, or an RM type as shown in FIG. 6 .
  • the above-mentioned PCB winding plate 62 can be sleeved on the magnetic column of the magnetic core 61 .
  • the above-mentioned PCB winding board 62 may include: a primary winding 621, a secondary winding 622 and a first noise cancelling winding 623, wherein:
  • the primary winding 621 refers to any winding connected to the primary circuit side except the first noise canceling winding 623
  • the secondary winding 622 refers to any winding except the first noise canceling winding 623 , connected to any winding on the secondary circuit side.
  • the primary winding 621 may include at least one primary winding layer.
  • Each primary winding layer included in the primary winding 621 may be represented by P1, P2, . . . , PN, and N is an integer greater than 1.
  • FIG. 7 in this application shows a schematic half-sectional view of the planar transformer 60 .
  • Figures 8 to 14 below show schematic half-section schematics of a planar transformer.
  • the above-mentioned at least one primary winding layer Pn may be provided with the coil of the primary power winding, or may also be provided with the coil of the primary auxiliary winding.
  • the above-mentioned coil may be formed of a conductive layer.
  • the coils of the above-mentioned primary power windings are connected in series with each other.
  • the primary auxiliary winding may refer to the winding that provides small power supply for other circuits besides the main power circuit in the power conversion circuit.
  • the above-mentioned other circuits other than the main power circuit may include, for example, circuits for driving, controlling, and detecting.
  • the above-mentioned primary winding 621 may include a first primary winding layer, and at least part of the coils of the primary power winding may be provided on the first primary winding layer, or at least part of the coils of the primary auxiliary winding may be provided.
  • the secondary winding 622 may include at least one secondary winding layer.
  • Each secondary winding layer included in the secondary winding 622 may be represented by S1, S2, . . . , SM, where M is an integer greater than 1.
  • the above-mentioned at least one secondary winding layer Sm may be provided with the coil of the secondary power winding, or may also be provided with the coil of the secondary auxiliary winding.
  • the coil of the secondary auxiliary winding may be any coil except the coil of the secondary power winding, which is not limited herein.
  • the above-mentioned secondary winding 622 may include a first secondary winding layer, and at least part of the coils of the secondary power winding may be provided on the first secondary winding layer, or at least part of the coils of the secondary auxiliary winding may also be provided.
  • the first noise cancellation winding 623 may include at least two noise cancellation winding layers. Each noise cancellation winding layer included in the first noise cancellation winding 623 may be represented by LB1, LB2, . . . , LBN.
  • the coils of the noise cancellation windings in the at least two noise cancellation winding layers are connected in series to form a first noise cancellation winding 623;
  • the first noise cancellation winding 623 includes a noise cancellation winding layer LB1 and a noise cancellation winding layer LB2, and the noise cancellation winding layer
  • One end of the coil of the noise canceling winding in LB1 is connected in series with one end of the coil of the noise canceling winding in the noise canceling winding layer LB2 to form a first noise canceling winding 623
  • the formed first noise canceling winding 623 has Two terminals, wherein the first terminal of the first noise canceling winding 623 is used for connecting the potential dead point of the secondary circuit of the power conversion circuit or for connecting the potential dead point of the primary circuit of the power conversion circuit, the first noise
  • the second end of the cancellation winding 623 is suspended; the noise cancellation winding layer where the second end of the first noise cancellation winding 623 is located is the first noise cancellation winding layer.
  • the first noise canceling winding layer when the first end of the first noise canceling winding 623 is used to connect the potential dead point of the secondary circuit, the first noise canceling winding layer is disposed between the first primary winding layer Pn and the first Between the primary winding layers Sm, and the first noise cancellation winding layer is adjacent to the first primary winding layer Pn; when the first end of the first noise cancellation winding 623 is used to connect the potential static of the primary circuit. , the first noise-cancelling winding layer is disposed between the first primary winding layer Pn and the first secondary winding layer Sm, and the first noise-cancelling winding layer is in phase with the first secondary winding layer Sm adjacent.
  • only one noise cancellation winding layer may be provided between the first primary winding layer and the first secondary winding layer, or two or more layers of noise cancellation winding layers may be provided, which is not limited herein.
  • the first noise canceling winding layer is disposed between the first primary winding layer and the first secondary winding layer, and when the first end of the first noise canceling winding is used to connect the potential dead point of the secondary circuit, the first A noise canceling winding layer is adjacent to the first primary winding layer.
  • the first noise canceling winding layer is in phase with the first secondary winding layer. Neighbors can be.
  • the first noise cancellation winding layer is provided between the first primary winding layer and the first secondary winding layer, which is not limited herein.
  • first noise cancellation winding layer is adjacent to the first primary winding layer means that there are no other winding layers between the first noise cancellation winding layer and the first primary winding layer, and the first noise cancellation winding layer is adjacent to the first noise cancellation winding layer.
  • Adjacent secondary winding layers means that there are no other winding layers between the first noise cancellation winding layer and the first secondary winding layer.
  • the floating second end of the first noise canceling winding may refer to that there is no electrical connection between the second end of the first noise canceling winding and any live conductor, or that the second end cannot be connected to the plane A transformer or other components in a power conversion circuit together form a closed loop.
  • the first noise canceling winding is arranged between the primary winding and the secondary winding of the planar transformer, and the number of coil turns of each noise canceling winding layer in the first noise canceling winding is designed, so that the When the planar transformer works, the induced voltage of the noise cancellation winding coil in the first noise cancellation winding layer can be used to cancel or compensate the induced voltage of the first secondary winding layer, so as to suppress the common mode generated by the secondary winding or the primary winding noise, thereby improving the performance of noise suppression.
  • the first noise canceling winding is formed by the coils of the noise canceling winding in at least two noise canceling winding layers in series
  • the first noise canceling layer disposed between the first primary winding layer and the first secondary winding layer is the noise-cancelling winding layer where the second end of the first noise-cancelling winding is located, so that the noise-cancelling winding coils of other noise-cancelling winding layers in the first noise-cancelling winding connected in series with the first noise-cancelling winding layer are used to
  • the induced voltage of the noise cancellation winding coil in the first noise winding layer is increased, so compared with the prior art, the first noise winding layer in the present application can achieve the required induced voltage with fewer coil turns.
  • the planar transformer provided in this application can further achieve the following effects:
  • the relative positions of the primary winding and the secondary winding may include at least the following three ways.
  • all the primary winding layers included in the primary winding may be located on one side of all the secondary winding layers included in the secondary winding.
  • the secondary windings may be arranged on both sides of the primary winding, that is, a part of the secondary winding layers in the secondary windings may be arranged on one side of the primary winding.
  • another part of the secondary winding layer is arranged on the other side of the primary winding to form a sandwich structure similar to a "sandwich".
  • the primary windings may be arranged on both sides of the secondary windings.
  • the primary winding layer (P) and the secondary winding layer (S) constitute a PS laminated layer structure.
  • the first noise cancellation winding 623 includes a noise cancellation winding layer LB1 and a noise cancellation winding layer LB2.
  • One end of the coil of the noise canceling winding in the noise canceling winding layer LB1 is connected in series with one end of the coil of the noise canceling winding in the noise canceling winding layer LB2 to form the first noise canceling winding 623, and the first noise canceling winding 623 is formed.
  • the winding 623 has two terminals, wherein the first terminal of the first noise canceling winding 623 is used to connect the potential dead point of the secondary circuit of the power conversion circuit or to the potential dead point of the primary circuit of the power conversion circuit , the second end of the first noise canceling winding 623 is suspended; the noise canceling winding layer LB1 where the second end of the first noise canceling winding 623 is located is the first noise canceling winding layer, and the other noise canceling winding layers LB2 are the second Noise cancellation winding layer, the first noise cancellation winding layer LB1 is disposed between the first primary winding layer P1 and the first secondary winding layer S1, and is adjacent to the first primary winding layer P1 and the first secondary winding layer S1 respectively .
  • the induced voltage of the noise-cancelling winding coil in the first noise-cancelling winding layer LB1 in the first noise-cancelling winding 623 can be used to cancel or compensate the voltage of the first secondary winding layer S1. Induced voltage to suppress common mode noise generated by secondary winding or primary winding, thereby improving noise suppression performance.
  • the noise cancellation coils of other noise cancellation winding layers LB2 connected in series with the first noise winding layer LB1 are used to increase the induced voltage of the noise cancellation winding coils in the first noise winding layer LB1. Therefore, the first noise cancellation coil in the present application Layers can achieve the desired induced voltage with fewer coil turns.
  • the number of layers of the second noise-cancelling winding layer in the first noise-cancelling winding is not limited to one, but may also be multiple layers.
  • the primary winding layer (P) and the secondary winding layer (S) constitute a PS laminated layer structure.
  • the first noise cancellation winding 623 includes a noise cancellation winding layer LB1 , a noise cancellation winding layer LB2 and a noise cancellation winding layer LB3 .
  • One end of the coil of the noise canceling winding in the noise canceling winding layer LB1 is connected in series with one end of the coil of the noise canceling winding in the noise canceling winding layer LB2, and the other end of the coil of the noise canceling winding in the noise canceling winding layer LB2 The end is connected in series with one end of the coil of the noise canceling winding in the noise canceling winding layer LB3, thereby forming the first noise canceling winding 623.
  • the formed first noise canceling winding 623 has two ends, wherein the first noise canceling winding 623 has two ends.
  • the first end of the noise cancellation winding 623 is used to connect to the potential dead point of the secondary circuit of the power conversion circuit or to the potential dead point of the primary circuit of the power conversion circuit, and the second end of the first noise cancellation winding 623 is floating ;
  • the noise canceling winding layer LB1 where the second end of the first noise canceling winding 623 is located is the first noise canceling winding layer, the noise canceling winding layer LB2 and the noise canceling winding layer LB3 are both the second noise canceling winding layer, the first noise canceling winding layer LB1
  • the offset winding layer LB1 is disposed between the first primary winding layer P1 and the first secondary winding layer S1 and is adjacent to the first primary winding layer P1 and the first secondary winding layer S1 respectively.
  • the induced voltage of the noise-cancelling winding coil in the first noise-cancelling winding layer LB1 in the first noise-cancelling winding 623 can be used to cancel or compensate the voltage of the first secondary winding layer S1. Induced voltage to suppress common mode noise generated by secondary winding or primary winding, thereby improving noise suppression performance.
  • the noise cancellation winding coils in other noise cancellation winding layers LB2 and LB3 connected in series with the first noise winding layer LB1 are used to increase the induced voltage of the noise cancellation winding coil in the first noise winding layer LB1. Therefore, the No. A noisy winding layer can achieve the desired induced voltage with fewer turns.
  • the number of coil turns in the first noise winding layer in this embodiment is less than that in the first noise winding layer in FIG. 7 .
  • the primary winding and the secondary winding when the primary winding and the secondary winding are arranged in a sandwich structure similar to a "sandwich", the primary winding and the secondary winding will have two adjacent faces, and the primary winding and the secondary winding only need If there are adjacent surfaces, common mode noise may be generated. Therefore, in order to further suppress the common mode noise generated by the secondary winding or the primary winding, thereby improving the noise suppression performance, the adjacent primary and secondary windings can be placed between the primary winding and the secondary winding. Noise canceling windings are installed.
  • the primary winding further includes a second primary winding layer; the secondary winding further includes a second secondary winding layer; between the second primary winding layer and the second secondary winding layer There is also at least one second noise canceling winding layer disposed therebetween, wherein the second noise canceling winding layer refers to other noise canceling layers in the first noise canceling winding except the first noise canceling winding layer winding layer. That is, the induced voltage of the cancellation winding coil in the second noise cancellation winding layer is used to cancel or compensate the induced voltage of the second secondary winding layer, so as to further suppress the common mode noise generated by the secondary winding or the primary winding, thereby improving the noise suppression effect. performance.
  • the primary winding layer (P) and the secondary winding layer (S) constitute an SPS laminated layer structure.
  • the first noise cancellation winding 623 includes a noise cancellation winding layer LB1 and a noise cancellation winding layer LB2.
  • One end of the coil of the noise canceling winding in the noise canceling winding layer LB1 is connected in series with one end of the coil of the noise canceling winding in the noise canceling winding layer LB2 to form the first noise canceling winding 623, and the first noise canceling winding 623 is formed.
  • the winding 623 has two terminals, wherein the first terminal of the first noise canceling winding 623 is used to connect the potential dead point of the secondary circuit of the power conversion circuit or to the potential dead point of the primary circuit of the power conversion circuit , the second end of the first noise canceling winding 623 is suspended; the noise canceling winding layer LB1 where the second end of the first noise canceling winding 623 is located is the first noise canceling winding layer, and the noise canceling winding layer LB2 is the second noise canceling layer
  • the winding layer, the first noise cancellation winding layer LB1 is disposed between the first primary winding layer P1 and the first secondary winding layer S1, and is adjacent to the first primary winding layer P1 and the first secondary winding layer S1 respectively.
  • the second noise cancellation winding layer LB2 is disposed between the second primary winding layer P2 and the second secondary winding layer S2, and is adjacent to the second primary winding layer P2 and the second secondary winding layer S2, respectively.
  • the induced voltage of the noise-cancelling winding coil in the first noise-cancelling winding layer LB1 in the first noise-cancelling winding 623 can be used to cancel or compensate the voltage of the first secondary winding layer S1. Induced voltage to suppress common mode noise generated by secondary winding or primary winding, thereby improving noise suppression performance.
  • the noise canceling winding coil in the second noise canceling winding layer LB2 connected in series with the first noise winding layer LB1 is used to increase the induced voltage of the noise canceling winding coil in the first noise winding layer LB1. Therefore, the first noise canceling coil in the present application
  • the noise winding layer can achieve the desired induced voltage with fewer turns.
  • the second noise cancellation winding layer LB2 is arranged between the second primary winding layer P2 and the second secondary winding layer S2, and the induced voltage of the cancellation winding coil in the second noise cancellation winding layer LB2 is used to cancel or compensate for the second time.
  • the induced voltage of the secondary winding layer can further suppress the common mode noise generated by the secondary winding or the primary winding, thereby improving the performance of noise suppression.
  • the first noise cancellation winding includes multiple layers of second noise cancellation winding layers
  • only one second noise cancellation winding layer may be arranged between the second primary winding layer and the second secondary winding layer.
  • multiple layers of the second noise canceling winding layer may also be provided, which is not limited here.
  • the second noise canceling winding where the noise canceling winding farthest away from the first end is located can be The cancellation winding layer is disposed between the second primary winding layer and the second secondary winding layer, and is adjacent to the second primary winding layer and the second secondary winding layer, respectively.
  • the second noise-cancelling winding layer where the noise-cancelling winding farthest from the first end is located and the noise-cancelling winding layer in the second noise-cancelling winding layer
  • the induced voltage of the winding is relatively the largest, so if the same induced voltage needs to be generated, the number of turns of the coil set in the second noise cancellation winding layer where the noise cancellation winding farthest from the first end is located can be the smallest.
  • the second noise canceling winding layer to be disposed between the second primary winding layer and the second secondary winding layer can also be determined according to the magnitude of the common mode noise to be compensated or canceled
  • the second noise canceling winding layer where the first end of the first noise canceling winding is located can also be arranged between the second primary winding layer and the second noise canceling winding layer. Between the secondary winding layers, it is not limited here.
  • the fact that the second noise cancellation winding layer is adjacent to the second primary winding layer and the second secondary winding layer respectively means that there is no other winding layer between the second noise cancellation winding layer and the second primary winding layer, and There are no other winding layers between the second noise cancelling winding layer and the second secondary winding layer.
  • the primary winding layer (P) and the secondary winding layer (S) constitute an SPS laminated layer structure.
  • the first noise cancellation winding 623 includes a noise cancellation winding layer LB1 , a noise cancellation winding layer LB2 and a noise cancellation winding layer LB3 .
  • One end of the coil of the noise canceling winding in the noise canceling winding layer LB1 is connected in series with one end of the coil of the noise canceling winding in the noise canceling winding layer LB2, and the other end of the coil of the noise canceling winding in the noise canceling winding layer LB2 The end is connected in series with one end of the coil of the noise canceling winding in the noise canceling winding layer LB3, thereby forming the first noise canceling winding 623.
  • the formed first noise canceling winding 623 has two ends, wherein the first noise canceling winding 623 has two ends.
  • the first end of the noise cancellation winding 623 is used to connect to the potential dead point of the secondary circuit of the power conversion circuit or to the potential dead point of the primary circuit of the power conversion circuit, and the second end of the first noise cancellation winding 623 is floating ;
  • the noise canceling winding layer LB1 where the second end of the first noise canceling winding 623 is located is the first noise canceling winding layer, the noise canceling winding layer LB2 and the noise canceling winding layer LB3 are both the second noise canceling winding layer, the first noise canceling winding layer LB1
  • the offset winding layer LB1 is disposed between the first primary winding layer S1 and the first secondary winding layer P1 and is adjacent to the first primary winding layer S1 and the first secondary winding layer P1 respectively.
  • the second noise cancellation winding layer LB2 is disposed between the second primary winding layer P2 and the second secondary winding layer S2, and is adjacent to the second primary winding layer P2 and the second secondary winding layer S2, respectively.
  • the induced voltage of the noise-cancelling winding coil in the first noise-cancelling winding layer LB1 in the first noise-cancelling winding 623 can be used to cancel or compensate the voltage of the first secondary winding layer S1. Induced voltage to suppress common mode noise generated by secondary winding or primary winding, thereby improving noise suppression performance.
  • the noise canceling winding coils in the second noise canceling winding layers LB2 and LB3 connected in series with the first noise winding layer LB1 are used to increase the induced voltage of the noise canceling winding coil in the first noise winding layer LB1.
  • the first noise winding layer can achieve the desired induced voltage with fewer coil turns.
  • the second noise cancellation winding layer LB2 is disposed between the second primary winding layer P2 and the second secondary winding layer S2, and the induced voltage of the cancellation winding coil in the second noise cancellation winding layer LB2 is used to cancel or compensate the second secondary winding layer.
  • the induced voltage of the winding layer S2 can further suppress the common mode noise generated by the secondary winding or the primary winding, thereby improving the performance of noise suppression.
  • the noise cancellation winding coil in the second noise cancellation winding layer LB3 connected in series with the second noise winding layer LB2 can increase the induced voltage of the noise cancellation winding coil in the second noise winding layer LB2.
  • the second noise cancellation winding layer LB2 The desired induced voltage can be achieved with fewer coil turns.
  • the second noise canceling winding layer where the noise canceling winding farthest from the first end is located can be disposed between the second primary winding layer and the second secondary winding layer, and adjacent to the second primary winding layer. If the first end of the first noise canceling winding is used to connect the potential dead point of the primary circuit, the second noise canceling winding layer where the noise canceling winding farthest from the first end is located may be connected It is arranged between the second primary winding layer and the second secondary winding layer, and is adjacent to the second secondary winding layer.
  • the primary winding layer (P) and the secondary winding layer (S) constitute a PSP laminated layer structure.
  • the first noise cancellation winding 623 includes a noise cancellation winding layer LB1 , a noise cancellation winding layer LB2 and a noise cancellation winding layer LB3 .
  • One end of the coil of the noise canceling winding in the noise canceling winding layer LB1 is connected in series with one end of the coil of the noise canceling winding in the noise canceling winding layer LB2, and the other end of the coil of the noise canceling winding in the noise canceling winding layer LB2 The end is connected in series with one end of the coil of the noise canceling winding in the noise canceling winding layer LB3, thereby forming the first noise canceling winding 623.
  • the formed first noise canceling winding 623 has two ends, wherein the first noise canceling winding 623 has two ends.
  • the first end of the noise cancellation winding 623 is used to connect to the potential dead point of the secondary circuit of the power conversion circuit or to the potential dead point of the primary circuit of the power conversion circuit, and the second end of the first noise cancellation winding 623 is floating ;
  • the noise canceling winding layer LB1 where the second end of the first noise canceling winding 623 is located is the first noise canceling winding layer LB1, and the noise canceling winding layer LB2 and the noise canceling winding layer LB3 are both the second noise canceling winding layer.
  • the noise cancellation winding layer LB1 is disposed between the first primary winding layer P1 and the first secondary winding layer SM, and is adjacent to the first primary winding layer P1 and the first secondary winding layer S1 respectively.
  • the second noise cancellation winding layers LB2 and LB3 are disposed between the second primary winding layer P2 and the second secondary winding layer S2.
  • the induced voltage of the noise-cancelling winding coil in the first noise-cancelling winding layer LB1 in the first noise-cancelling winding 623 can be used to cancel or compensate the voltage of the first secondary winding layer S1. Induced voltage to suppress common mode noise generated by secondary winding or primary winding, thereby improving noise suppression performance.
  • the noise canceling winding coils in the second noise canceling winding layers LB2 and LB3 connected in series with the first noise winding layer LB1 are used to increase the induced voltage of the noise canceling winding coil in the first noise winding layer LB1.
  • the The first noise winding layer can achieve the desired induced voltage with fewer coil turns.
  • the second noise canceling winding layers LB2 and LB3 are disposed between the second primary winding layer P2 and the second secondary winding layer S2, and the induced voltage of the canceling coil in the second noise canceling winding layer LB2 or LB3 is canceled or compensated
  • the induced voltage of the second secondary winding layer S2 can further suppress the common mode noise generated by the secondary winding or the primary winding, thereby improving the performance of noise suppression.
  • the working principle of the first noise cancellation winding 623 is as follows:
  • the capacitance of the noise canceling winding in the noise canceling winding layer LB1 relative to the adjacent secondary winding is Cc1
  • the number of coil turns of the noise canceling winding in the noise canceling winding layer LB1 is Nb1
  • the capacitance of the noise cancellation winding in the noise cancellation winding layer LB1 relative to the adjacent secondary winding is Cc2
  • the number of turns of the noise cancellation winding in the noise cancellation winding layer LB1 is Nb2.
  • the two noise cancellation winding layers are independent of each other, and one end is connected to a potential static point, and one end is suspended.
  • the noise canceling winding of the series structure of the present application is compared with the noise canceling winding of the existing parallel structure:
  • the noise canceling winding of the present application generates 1.5 times the reverse noise charge of the prior art under the same configuration of the number of turns of the noise canceling winding. Furthermore, it can be deduced that the number of turns of the noise cancellation winding of the present application can be reduced by 50% under the condition of generating the same magnitude of reverse noise charge.
  • the coil turn width of the noise cancellation winding in the first noise cancellation winding layer LB1 is larger than the coil turn width of the noise cancellation winding in the second noise cancellation winding layer LB2 . That is, the coil turn width is designed to be wider in the noise canceling winding layer where the second end of the first noise canceling winding 623 is located. In contrast, the noise canceling winding layer where the first end of the first noise canceling winding 623 is located is designed The turn width of the middle coil is designed to be narrower. This can further reduce the number of turns of the first noise cancelling winding.
  • the working principle of the first noise cancellation winding in the above embodiment will be described below in combination with the principle:
  • each turn of the transformer is V0.
  • the first end of the first noise canceling winding is connected to the potential dead point of the primary circuit or the secondary circuit, the voltage of the first turn of the coil connected to the first end is V0, and the voltage of the first turn of the coil connected to the first end is V0 At the beginning, it is defined as the 2nd turn coil, the 3rd turn coil...the nth turn coil. Since each turn of the coil is a series structure, the induced voltage of the nth turn coil is nV0. Thereby, the farther the coil is from the first end (or the turn closer to the second end), the higher the induced voltage.
  • the coil turn widths of the noise cancellation windings in the first noise cancellation winding layer LB1 are the same.
  • the coil of the noise canceling winding that is closer to the second end has a larger turn width of the coil.
  • the PCB winding plate 62 further includes an auxiliary winding 624 , and the auxiliary winding 624 may be disposed in at least one layer of the second noise canceling winding layer.
  • the second noise canceling winding layer is mainly used to increase the induced voltage of the coil in the first noise canceling winding layer
  • the auxiliary winding 624 is arranged in the second noise canceling winding layer without affecting the first noise cancel the winding layers.
  • the number of layers of windings in the PCB winding board 62 can be reduced, the space utilization rate of the planar transformer can be improved, and the cost of the planar transformer can be saved.
  • auxiliary winding 624 may be any other type of winding except the noise cancellation winding, which is not limited herein.
  • FIG. 15 is a schematic diagram of the connection relationship between the power conversion circuit 50 and the planar transformer 60 according to the embodiment of the present application.
  • the primary circuit 51 includes a primary switch tube 511 , a primary filter capacitor 512 and a rectifier circuit.
  • the secondary circuit 52 includes a secondary rectifier tube 521 and a secondary filter capacitor 522 .
  • the primary filter capacitor 512 and the secondary filter capacitor 522 can be electrolytic capacitors.
  • the node connected to any one of the two ends of the primary filter capacitor 512 is the potential dead point of the primary circuit, or the ground node of the primary circuit may also be the potential dead point of the primary circuit.
  • the node connected to any one of the two ends of the secondary filter capacitor 522 is the potential dead point of the secondary circuit.
  • one end of the primary winding 621 is used for static connection with the primary potential of the power conversion circuit 50 .
  • One end of the secondary winding 622 is used to connect to the secondary potential static point of the power conversion circuit.
  • both ends of the primary winding 621 may be connected to the primary switch tube 511 and the primary filter capacitor 512 respectively, and both ends of the secondary winding 622 may be connected to the secondary rectifier tube 521 and the secondary filter capacitor 522 respectively.
  • the first end of the first noise canceling winding 623 is used for electrostatic connection with the potential static point of the primary circuit of the power conversion circuit 50 or the potential of the secondary circuit, and the second end of the first noise canceling winding 623 can be suspended.
  • the above-mentioned floating may mean that there is no electrical connection between the second end of the first noise cancellation winding 623 and any conductor, and no electrical connection with any element.
  • the first end of the first noise cancellation winding 623 may be connected to the primary filter capacitor 512 .
  • an embodiment of the present application further provides an adapter 100 .
  • the adapter 100 may include a casing 101 and a power conversion circuit 50 disposed in the casing 101 . Since the principle of the adapter for solving the problem is similar to that of the aforementioned power conversion circuit, the implementation of the adapter can refer to the implementation of the aforementioned power conversion circuit, and the repetition will not be repeated.
  • a first noise canceling winding is arranged between the primary winding and the secondary winding of the planar transformer, and by designing the noise canceling winding layer of each noise canceling winding in the first noise canceling winding The number of coil turns, so that when the planar transformer works, the induced voltage of the noise cancellation winding coil in the first noise cancellation winding layer can be used to cancel or compensate the induced voltage of the first secondary winding layer, so as to suppress the secondary winding layer.
  • the common mode noise generated by the secondary winding or the primary winding is eliminated, thereby improving the performance of noise suppression.
  • the first noise canceling winding is formed by the coils of the noise canceling winding in at least two noise canceling winding layers in series
  • the first noise canceling layer disposed between the first primary winding layer and the first secondary winding layer is the noise-cancelling winding layer where the second end of the first noise-cancelling winding is located, so that the noise-cancelling winding coils of other noise-cancelling winding layers in the first noise-cancelling winding connected in series with the first noise-cancelling winding layer are used to
  • the induced voltage of the noise cancellation winding coil in the first noise winding layer is increased, so compared with the prior art, the first noise winding layer in the present application can achieve the required induced voltage with fewer coil turns.
  • the disclosed system, apparatus and method may be implemented in other manners.
  • the apparatus embodiments described above are only illustrative.
  • the division of the units is only a logical function division. In actual implementation, there may be other division methods.
  • multiple units or components may be combined or Can be integrated into another system, or some features can be ignored, or not implemented.
  • the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection of devices or units, and may be in electrical, mechanical or other forms.
  • the units described as separate components may or may not be physically separated, and components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.
  • each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit.

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Abstract

本申请提供了一种平面变压器、电源转换电路及适配器，在平面变压器的初级绕组和次级绕组之间设置第一噪声抵消绕组，并且通过设计第一噪声抵消绕组中各噪声抵消绕组层的线圈匝数，以使得在平面变压器工作时，第一噪声抵消绕组层中的噪声抵消绕组线圈的感应电压能够用于抵消或者补偿第一次级绕组层的感应电压，以抑制次级绕组或者初级绕组产生的共模噪声，从而提高噪声抑制的性能。并且，由于第一噪声抵消绕组由至少两个噪声抵消绕组层串联形成，利用第一噪声抵消绕组中与该第一噪声绕组层串联的其它噪声抵消绕组层来提高第一噪声绕组层的感应电压，因此与现有技术相比，本申请中的第一噪声绕组层可以采用较少的线圈匝数就到达所需要的感应电压。

Description

平面变压器、电源转换电路及适配器
相关申请的交叉引用
本申请要求在2020年10月28日提交中国专利局、申请号为202011174200.0、申请名称为“平面变压器、电源转换电路及适配器”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及电路技术领域，尤指一种平面变压器、电源转换电路及适配器。
背景技术
开关电源以其效率高、体积小、输出稳定性好的优点而迅速发展起来。但是开关电源工作过程中的电磁干扰问题非常突出。开关电源的电磁干扰主要来自外界的干扰源、自身开关器件关断和导通、整流二极管方向恢复、电容/电感/导线产生的噪声，这些噪声信号会沿着电路网络传导和辐射到用电设备，导致电磁干扰。因而开关电源对噪声抑制的要求非常严格。
开关电源的噪声分为差模噪声和共模噪声，差模噪声主要包括由开关变换器的脉动电流引起的噪声。共模噪声主要包括由开关电源电路各参数间相互作用而产生的对参考地之间的噪声。在实际的工程应用中，往往共模噪声是导致电磁干扰的主要因素。因此，如何降低甚至消除开关电源的共模噪声是业界非常关注的问题。
发明内容
本申请提供了一种平面变压器、电源转换电路及适配器，能够提高噪声抑制的性能。
第一方面，本申请提供的一种平面变压器，包括磁芯和印刷电路板PCB绕组板，其中所述PCB绕组板包括：初级绕组，次级绕组和第一噪声抵消绕组。其中，所述初级绕组包括第一初级绕组层，所述次级绕组包括第一次级绕组层，所述第一噪声抵消绕组包括至少两个噪声抵消绕组层，且所述至少两个噪声抵消绕组层中的噪声抵消绕组的线圈依次串联形成所述第一噪声抵消绕组；所述第一噪声抵消绕组的第一端头用于连接电源转换电路的次级电路的电位静点或者用于连接所述电源转换电路的初级电路的电位静点，所述第一噪声抵消绕组的第二端头悬空；所述第一噪声抵消绕组的第二端头所在的所述噪声抵消绕组层为第一噪声抵消绕组层，所述第一噪声抵消绕组层设置于所述第一初级绕组层与所述第一次级绕组层之间，且当所述第一噪声抵消绕组的第一端头用于连接所述次级电路的电位静点时，所述第一噪声抵消绕组层与所述第一初级绕组层相邻，当所述第一噪声抵消绕组的第一端头用于连接所述初级电路的电位静点时，所述第一噪声抵消绕组层与所述第一次级绕组层相邻。
在本申请实施例中，在平面变压器的初级绕组和次级绕组之间设置第一噪声抵消绕组，并且通过设计第一噪声抵消绕组中各噪声抵消绕组层的线圈匝数，以使得在所述平面变压器工作时，所述第一噪声抵消绕组层中的噪声抵消绕组线圈的感应电压能够用于抵消或者 补偿第一次级绕组层的感应电压，以抑制次级绕组或者初级绕组产生的共模噪声，从而提高噪声抑制的性能。并且，由于第一噪声抵消绕组由至少两个噪声抵消绕组层中的噪声抵消绕组的线圈依次串联形成，而设置于第一初级绕组层和第一次级绕组层之间的第一噪声绕组层是所述第一噪声抵消绕组的第二端头所在的噪声抵消绕组层，这样利用所述第一噪声抵消绕组中与该第一噪声绕组层串联的其它噪声抵消绕组层的噪声抵消绕组线圈来提高第一噪声绕组层中噪声抵消绕组线圈的感应电压，因此与现有技术相比，本申请中的第一噪声绕组层可以采用较少的线圈匝数就到达所需要的感应电压。
在本申请中，第一初级绕组层与第一次级绕组层之间可以仅设置一层噪声抵消绕组层也可以设置两层或者多层噪声抵消绕组层，在此不作限定。只要保证第一噪声抵消绕组层设置于第一初级绕组层与第一次级绕组层之间，且当第一噪声抵消绕组的第一端头用于连接次级电路的电位静点时，第一噪声抵消绕组层与第一初级绕组层相邻，当第一噪声抵消绕组的第一端头用于连接初级电路的电位静点时，第一噪声抵消绕组层与第一次级绕组层相邻即可。
在本申请中，所述初级绕组还可以包括第二初级绕组层；所述次级绕组还可以包括第二次级绕组层；在所述第二初级绕组层与所述第二次级绕组层之间还设置有至少一层第二噪声抵消绕组层，其中，所述第二噪声抵消绕组层是指所述第一噪声抵消绕组中除了所述第一噪声抵消绕组层之外的其它噪声抵消绕组层。即利用所述第二噪声抵消绕组层中抵消绕组线圈的感应电压抵消或者补偿第二次级绕组层的感应电压，以进一步抑制次级绕组或者初级绕组产生的共模噪声，从而提高噪声抑制的性能。
在一种可能的实现方式中，距离所述第一端头最远的噪声抵消绕组所在的所述第二噪声抵消绕组层设置于所述第二初级绕组层与所述第二次级绕组层之间，且分别与所述第二初级绕组层和所述第二次级绕组层相邻。这是因为，在所有的第二噪声抵消绕组层中，距离所述第一端头最远的噪声抵消绕组所在的所述第二噪声抵消绕组层，所述第二噪声抵消绕组层中噪声抵消绕组的感应电压相对最大，因此如若需要产生相同的感应电压，距离所述第一端头最远的噪声抵消绕组所在的所述第二噪声抵消绕组层中设置的线圈的匝数可以是最少的。
在一种可能的实现方式中，如果需要补偿或抵消的共模噪声较小，可以将所述第一端头所在的所述第二噪声抵消绕组层设置于所述第二初级绕组层与所述第二次级绕组层之间，且分别与所述第二初级绕组层和所述第二次级绕组层相邻。
可选地，在本申请中，所述第一噪声抵消绕组层中的噪声抵消绕组的线圈匝宽大于所述第二噪声抵消绕组层中的噪声抵消绕组的线圈匝宽。即第一噪声抵消绕组的第二端头所在的噪声抵消绕组层中线圈匝宽设计的更宽，而相比之下，第一噪声抵消绕组的第一端头所在的噪声抵消绕组层中线圈匝宽设计的更窄。这样可以进一步降低第一噪声抵消绕组的线圈匝数。
在一种可能的实现方式中，所述第一噪声抵消绕组层中的噪声抵消绕组的线圈匝宽相同。
在一种可能的实现方式中，所述第一噪声抵消绕组层中，离所述第二端头越近的噪声抵消绕组的线圈，线圈匝宽越大。
可选地，在本申请中，所述PCB绕组板还包括辅助绕组，所述辅助绕组设置于至少一层所述第二噪声抵消绕组层中。由于所述第二噪声抵消绕组层主要用于提升第一噪声抵消 绕组层中线圈的感应电压，因此，将所述辅助绕组设置于所述第二噪声抵消绕组层中不会影响第一噪声抵消绕组层。并且，可以减少PCB绕组板中绕组的层数，提高平面变压器的空间利用率，从而节约平面变压器的成本。
在具体实施时，所述辅助绕组可以使除了噪声抵消绕组之外的其它任意类型绕组，在此不作限定。
在本申请中，上述初级绕组和次级绕组的相对位置可以至少包括以下三种方式。例如，在第一种方式中，初级绕组包括的全部初级绕组层可以位于次级绕组包括的全部次级绕组层的其中一侧。或者，在第二种形式中，可以将次级绕组设置在初级绕组的两侧，即，将次级绕组中的一部分次级绕组层设置在初级绕组的一侧，将次级绕组的另一部分次级绕组层设置在初级绕组的另一侧，构成类似于“三明治”的夹层结构。采用上述“三明治”结构可以降低绕组的高频涡流损耗和漏感。或者，在第三种方式中，也可以将初级绕组设置在次级绕组的两侧。
第二方面，本申请提供的一种电源转换电路，包括：初级电路、次级电路以及第一方面中任一种平面变压器，所述平面变压器设置在所述初级电路和所述次级电路之间。
第三方面、本申请提供的一种适配器，包括外壳和第二方面所述的电源转换电路，其中，所述电源转换电路设置于所述外壳内。
附图说明
图1是本申请实施例提供的一种可能的应用场景的示意图；
图2是本申请一种实施例提供的电源转换电路的示意图；
图3是本申请又一实施例提供的电源转换电路的示意图；
图4是本申请实施例的噪声抑制的方法示意图；
图5是相关技术中提供的平面变压器的截面示意图；
图6是本申请实施例的平面变压器的结构示意图；
图7是本申请又一实施例的平面变压器的截面示意图；
图8是本申请另一实施例的平面变压器的截面示意图；
图9是本申请另一实施例的平面变压器的截面示意图；
图10是本申请另一实施例的平面变压器的截面示意图；
图11是本申请另一实施例的平面变压器的截面示意图；
图12是本申请另一实施例的平面变压器的截面示意图；
图13是本申请另一实施例的平面变压器的截面示意图；
图14是本申请另一实施例的平面变压器的截面示意图；
图15是本申请实施例的电源转换电路与平面变压器的连接关系示意图；
图16是本申请实施例提供的适配器的结构示意图。
具体实施方式
为了使本申请的目的、技术方案和优点更加清楚，下面将结合附图对本申请作进一步地详细描述。然而，示例实施方式能够以多种形式实施，且不应被理解为限于在此阐述的实施方式；相反，提供这些实施方式使得本申请更全面和完整，并将示例实施方式的构思 全面地传达给本领域的技术人员。在图中相同的附图标记表示相同或类似的结构，因而将省略对它们的重复描述。本申请中所描述的表达位置与方向的词，均是以附图为例进行的说明，但根据需要也可以做出改变，所做改变均包含在本申请保护范围内。本申请的附图仅用于示意相对位置关系不代表真实比例。
需要说明的是，在以下描述中阐述了具体细节以便于充分理解本申请。但是本申请能够以多种不同于在此描述的其它方式来实施，本领域技术人员可以在不违背本申请内涵的情况下做类似推广。因此本申请不受下面公开的具体实施方式的限制。说明书后续描述为实施本申请的较佳实施方式，然所述描述乃以说明本申请的一般原则为目的，并非用以限定本申请的范围。本申请的保护范围当视所附权利要求所界定者为准。
为了便于了解本申请实施例，下面首先介绍本申请实施例涉及的一些术语。
平面变压器(Planar transformer)：区别于传统的变压器结构，平面变压器的磁芯、绕组是平面结构。磁芯一般采用小尺寸的E型、RM型磁芯结构，绕组一般采用多层印刷电路板(Printed circuit board，PCB)迭绕而成，这种设计有较低的直流电阻、较小的漏感和分布电容，高度很小，可以有较高的工作频率。
反激变换器(Flyback converter)：广泛应用于交流/直流(AC/DC)和直流/直流(DC/DC)转换，是较为常见的小功率开关电源变换器，具有结构简单，成本低廉的优点。其核心部件包括功率开关管，变压器、二极管和电容。功率开关管由脉冲宽度调制控制，通过闭合与导通在变压器初级线圈中产生高频方波信号，再感应耦合到变压器的次级线圈，实现能量的传递。通过次级电路的二极管和电容的滤波整流作用，在输出端得到稳定的直流输出。
共模噪声：共模噪声又称为非对称噪声或线路对地的噪声，在使用交流电源的电气设备都存在这种噪声，共模噪声的电流在两个输电线上以相同的方向流动且对地的相位保持相同，并通过地线返回。
电位静点：在电路网络中，该网络节点上的电压电位幅值在电路工作过程中保持相对恒定，没有高频的跳跃或者震荡。比如：反激变换器初级侧电路整流后的滤波电容和次级侧电路整流后的滤波电容，这些电容的正极或者负极及直接与其相连接的网络节点即为电位静点。
绕组层：在平面变压器中，绕组层指在绕组中位于同一平面的多匝线圈。该平面与绕组所围绕的磁芯中轴线垂直，多匝线圈可以由内向外或由外向内的在同一个平面上平行缠绕。在一个绕组中，可能存在多个绕组层，每个绕组层所在的平面相互平行，垂直于磁芯中轴线排布。相应的，两个相邻的绕组层指两个绕组层所在平面平行，且中间不存在另一绕组层的两个绕组层。
本申请提供了一种平面变压器、电源转换电路以及适配器。其中，上述平面变压器可以设置于电源转换电路中，上述电源转换电路可以设置于适配器中。
具体地，适配器可以应用于为设备充电或供电的场景。例如，图1示出了本申请实施例的一种可能的应用场景。如图1所示，该应用场景包括外部电源11、适配器12以及待充电设备13。例如，上述待充电设备13可以包括蜂窝电话、笔记本电脑、电池等，本申请实施例对此并不限定。通常情况下，适配器12可以与外部电源11连接，适配器12包括的电源转换电路用于将外部电源11提供的较高电压转换为符合待充电设备13充电或供电标准的较低电压，并为待充电设备13进行充电或供电。
本申请实施例的提供的平面变压器能够降低工作时产生的噪声。上述噪声可以包括共 模噪声。上述电源转换电路可以是开关电源变换器，例如，开关电源变换器可以包括上述反激变换器。共模噪声主要由开关电源电路各参数间相互作用而产生的对参考地之间的噪声，下面结合图2和图3，介绍电源转换电路20中的共模噪声产生和传输的机理。
如图2所示，电源转换电路20通常包括初级电路21、次级电路22以及变压器23。如图3所示，初级电路通常包括初级开关管211、初级滤波电容212。进一步地，初级电路还包括整流电路。上述初级开关管211也可以称为功率开关管。次级电路22通常包括次级整流管221和次级滤波电容222。变压器23包括初级绕组231、磁芯以及次级绕组232。初级绕组231可以与初级开关管211以及初级滤波电容212相连，次级绕组232可以与次级整流管221以及次级滤波电容222相连。初级滤波电容212和次级滤波电容222通常采用电解电容。
通常情况下，与初级滤波电容212的两端中的任意一端相连的节点为初级电路的电位静点，或者，初级电路的地节点也可以为初级电路的电位静点。与次级滤波电容222的两端中的任意一端相连的节点为次级电路的电位静点。
在电源转换电路20工作时，外部电源11输入的交流电通过初级电路21的整流滤波之后，转变为稳定的高压直流电输入至变压器23的初级绕组231。与初级绕组231相连的初级开关管211通过高频导通与关断，将初级绕组231上的电压耦合到次级绕组232上。耦合到次级绕组232的电压通过次级电路22的整流滤波之后，向负载输出低压直流电，为负载充电或供电。其中，上述负载即上述待充电设备13。在上述电源转换电路20的工作过程中，初级开关管211由于高频的导通与关断，产生跳变电压Vp，次级整流管221由于高频的导通与关断，产生跳变电压Vs。
由于变压器的初级绕组231和次级绕组232之间存在寄生电容，跳变电压Vp和Vs通过上述寄生电容在电源转换电路20中产生共模噪声。具体地，参见图3所示，上述寄生电容包括初级绕组对次级绕组之间的分布电容Cps和次级绕组对初级绕组的分布电容Csp。初级电路中的跳变电压Vp通过Cps产生流向地的噪声电流Ips，次级电路中的跳变电压Vs通过Csp产生流向地的噪声电流Isp。上述噪声电流Ips和噪声电流Isp即为共模噪声。
如何抑制上述共模噪声，是当前业界设计具有较强竞争力的适配器的难点之一。
需要说明的是，图3中还示出了线路阻抗稳定网络(Line Impedance Stabilization Network,LISN)电路，LISN电路是一种测试电路，用于检测电源转换电路工作时流入地的共模噪声电流，换句话说，可以认为LISN网络检测到的对地电流等效为电源转换电路产生的共模噪声。
图4是相关技术的抑制噪声的方法示意图。参见图4所示，在相关技术中，在平面变压器23中引入噪声抵消绕组233来产生反向噪声电流，通过调节噪声抵消绕组233的匝数来调节反向噪声电流的大小，可以实现反向噪声与原噪声相互抵消。图5是相关技术中的平面变压器中绕组的剖面结构示意图。如图5所示，噪声抵消绕组层B1和B2分别设置在初级绕组231和次级绕组232之间，且噪声抵消绕组层B1和B2中分别设置有Nb匝的噪声抵消绕组233，每一噪声抵消绕组层B1或B2中的噪声抵消绕组233的一端头均接初级电路的电位静点，另一端头均悬空。
但是，在实际的工程应用中，噪声抵消绕组的匝数一般取值较大，约大于4匝。匝数过多会带来如下缺点：(1)噪声抵消绕组层的绕线通道宽度有限，最大匝数有限，可能导 致无法提供足够的反向噪声电流；(2)噪声抵消绕组中匝与匝之间需要预留一定的加工间距，匝数过多会导致噪声抵消绕组对初级功率绕组屏蔽不完整，且匝数越多，屏蔽效果越差；(3)噪声抵消绕组层中噪声抵消绕组匝数较多时，加工累计公差较大，导致噪声一致性比较差。
针对上述问题，本申请实施例提出了一种具有较低共模噪声的平面变压器，采用该平面变压器的电源变换电路具有较高的噪声抑制性能，且可以降低噪声抵消绕组的匝数。另外，本申请还提供了应用该平面变压器的电源变换电路，以及应用该电源变换电路的适配器。具体的，平面变压器、电源转换电路以及适配器可以参见图1至图3中的描述，为了简洁，这里不再赘述。
本申请实施例中提供的变压器主要由磁芯和绕组线圈组成。其中，绕组线圈可以是传统的铜线烧制，也可以是由多层PCB经过刻蚀而成的PCB绕组板。后者相对前者由于更加扁平化，所以一般被称为平面变压器。图6示出了平面变压器60的一种结构示意图。如图6所示，该平面变压器60包括磁芯61和PCB绕组板62。
本申请实施例对磁芯61的材质以及形状不作限定。例如，磁芯61的形状可以为EE型、EI型或者如图6所示的RM型。上述PCB绕组板62可以套设于该磁芯61的磁柱上。
如图6所示，上述PCB绕组板62可以包括：初级绕组621、次级绕组622和第一噪声抵消绕组623，其中：
在本申请中，所述初级绕组621是指除所述第一噪声抵消绕组623外，连接于初级电路侧的任意绕组，所述次级绕组622是指除所述第一噪声抵消绕组623外，连接于次级电路侧的任意绕组。
所述初级绕组621可以包括至少一个初级绕组层。初级绕组621包括的各初级绕组层可以用P1、P2、…、PN表示，N为大于1的整数。需要说明的是，由于平面变压器60的截面是对称的，因此，本申请中的图7展示的为平面变压器60的半截面示意图。类似地，下文中的图8至图14展示了平面变压器的半截面示意图。
上述至少一个初级绕组层Pn(n＝1～N的任意整数)可以设置有初级功率绕组的线圈，或者，还可以设置初级辅助绕组的线圈。上述线圈可以采用导电层构成。上述初级功率绕组的线圈相互串联。初级辅助绕组可以指在电源转换电路中为除主功率电路之外的其他电路提供小功率电源的绕组。上述除主功率电路之外的其他电路，例如可以包括驱动、控制、检测等电路。
上述初级绕组621可以包括第一初级绕组层，第一初级绕组层上可以设置有初级功率绕组的至少部分线圈，或者，也可以设置初级辅助绕组的至少部分线圈。
所述次级绕组622可以包括至少一个次级绕组层。次级绕组622包括的各次级绕组层可以用S1、S2、…、SM表示，M为大于1的整数。与初级绕组621相似，上述至少一个次级绕组层Sm(m＝1～M的任意整数)上设置的线圈相互串联。上述至少一个次级绕组层Sm可以设置有次级功率绕组的线圈，或者，还可以设置次级辅助绕组的线圈。次级辅助绕组的线圈可以是除次级功率绕组的线圈之外的任何线圈，在此不作限定。
上述次级绕组622可以包括第一次级绕组层，第一次级绕组层上可以设置有次级功率绕组的至少部分线圈，或者，也可以设置次级辅助绕组的至少部分线圈。
所述第一噪声抵消绕组623可以包括至少两个噪声抵消绕组层。第一噪声抵消绕组623包括的各噪声抵消绕组层可以用LB1、LB2、…、LBN表示。
该至少两个噪声抵消绕组层中的噪声抵消绕组的线圈依次串联形成第一噪声抵消绕组623；例如该第一噪声抵消绕组623包括噪声抵消绕组层LB1和噪声抵消绕组层LB2，噪声抵消绕组层LB1中的噪声抵消绕组的线圈的一个端头与噪声抵消绕组层LB2中的噪声抵消绕组的线圈的一个端头串联起来形成第一噪声抵消绕组623，形成的该第一噪声抵消绕组623会有两个端头，其中，第一噪声抵消绕组623的第一端头用于连接电源转换电路的次级电路的电位静点或者用于连接电源转换电路的初级电路的电位静点，第一噪声抵消绕组623的第二端头悬空；第一噪声抵消绕组623的第二端头所在的噪声抵消绕组层为第一噪声抵消绕组层。
需要强调说明的是：当第一噪声抵消绕组623的第一端头用于连接所述次级电路的电位静点时，所述第一噪声抵消绕组层设置于第一初级绕组层Pn与第一次级绕组层Sm之间，且所述第一噪声抵消绕组层与第一初级绕组层Pn相邻；当第一噪声抵消绕组623的第一端头用于连接所述初级电路的电位静点时，所述第一噪声抵消绕组层设置于第一初级绕组层Pn与第一次级绕组层Sm之间，且所述第一噪声抵消绕组层与所述第一次级绕组层Sm相邻。
在本申请中，第一初级绕组层与第一次级绕组层之间可以仅设置一层噪声抵消绕组层也可以设置两层或者多层噪声抵消绕组层，在此不作限定。只要保证第一噪声抵消绕组层设置于第一初级绕组层与第一次级绕组层之间，且当第一噪声抵消绕组的第一端头用于连接次级电路的电位静点时，第一噪声抵消绕组层与第一初级绕组层相邻，当第一噪声抵消绕组的第一端头用于连接初级电路的电位静点时，第一噪声抵消绕组层与第一次级绕组层相邻即可。
在具体实施时，一般在第一初级绕组层与第一次级绕组层之间仅设置第一噪声抵消绕组层，在此不作限定。
进一步需要说明的是，第一噪声抵消绕组层与第一初级绕组层相邻是指第一噪声抵消绕组层与第一初级绕组层之间不存在其他绕组层，第一噪声抵消绕组层与第一次级绕组层相邻是指第一噪声抵消绕组层与第一次级绕组层之间不存在其他绕组层。
本申请实施例中，第一噪声抵消绕组的第二端头悬空可以指该第一噪声抵消绕组的第二端头与任何带电导体之间不存在电连接，或者该第二端头不能与平面变压器或电源转换电路中的其他部件一起形成闭合回路。
在本申请实施例中，在平面变压器的初级绕组和次级绕组之间设置第一噪声抵消绕组，并且通过设计第一噪声抵消绕组中各噪声抵消绕组层的线圈匝数，以使得在所述平面变压器工作时，所述第一噪声抵消绕组层中的噪声抵消绕组线圈的感应电压能够用于抵消或者补偿第一次级绕组层的感应电压，以抑制次级绕组或者初级绕组产生的共模噪声，从而提高噪声抑制的性能。并且，由于第一噪声抵消绕组由至少两个噪声抵消绕组层中的噪声抵消绕组的线圈依次串联形成，而设置于第一初级绕组层和第一次级绕组层之间的第一噪声绕组层是所述第一噪声抵消绕组的第二端头所在的噪声抵消绕组层，这样利用所述第一噪声抵消绕组中与该第一噪声绕组层串联的其它噪声抵消绕组层的噪声抵消绕组线圈来提高第一噪声绕组层中噪声抵消绕组线圈的感应电压，因此与现有技术相比，本申请中的第一噪声绕组层可以采用较少的线圈匝数就到达所需要的感应电压。
正是由于本申请中第一噪声绕组层可以采用较少的线圈匝数就到达所需要的感应电压，因此本申请提供的平面变压器可以进一步达到如下效果：
(1)有效减少第一噪声抵消绕组层中的噪声抵消绕组的线圈匝数；
(2)可以在第一噪声抵消绕组层的有限的绕线通道中通过较少的噪声抵消绕组匝数提供足够的反向噪声电流；
(3)通过降低第一噪声抵消绕组层中噪声抵消绕组的线圈匝数，可以减少第一噪声抵消绕组层中匝与匝之间的间距总和，进而提升第一噪声抵消绕组层与第一初级功率绕组层或第一次级功率绕组层的屏蔽效果；
(4)通过降低第一噪声抵消绕组层中噪声抵消绕组的线圈匝数，可以减小加工的累计公差，提升噪声一致性。
在具体实施时，在本申请中，上述初级绕组和次级绕组的相对位置可以至少包括以下三种方式。例如，在第一种方式中，如图7和图8所示，初级绕组包括的全部初级绕组层可以位于次级绕组包括的全部次级绕组层的其中一侧。或者，在第二种形式中，如图9和图10所示，可以将次级绕组设置在初级绕组的两侧，即，将次级绕组中的一部分次级绕组层设置在初级绕组的一侧，将次级绕组的另一部分次级绕组层设置在初级绕组的另一侧，构成类似于“三明治”的夹层结构。采用上述“三明治”结构可以降低绕组的高频涡流损耗和漏感。或者，在第三种方式中，如图11所示，也可以将初级绕组设置在次级绕组的两侧。
示例性的，如图7所示，初级绕组层(P)和次级绕组层(S)构成PS层叠层结构。第一噪声抵消绕组623包括噪声抵消绕组层LB1和噪声抵消绕组层LB2。噪声抵消绕组层LB1中的噪声抵消绕组的线圈的一个端头与噪声抵消绕组层LB2中的噪声抵消绕组的线圈的一个端头串联起来形成第一噪声抵消绕组623，形成的该第一噪声抵消绕组623会有两个端头，其中，第一噪声抵消绕组623的第一端头用于连接电源转换电路的次级电路的电位静点或者用于连接电源转换电路的初级电路的电位静点，第一噪声抵消绕组623的第二端头悬空；第一噪声抵消绕组623的第二端头所在的噪声抵消绕组层LB1为第一噪声抵消绕组层，其它的噪声抵消绕组层LB2为第二噪声抵消绕组层，第一噪声抵消绕组层LB1设置于第一初级绕组层P1与第一次级绕组层S1之间，且分别与第一初级绕组层P1和第一次级绕组层S1相邻。
在上述实施例中，在平面变压器工作时，第一噪声抵消绕组623中的第一噪声抵消绕组层LB1中的噪声抵消绕组线圈的感应电压能够用于抵消或者补偿第一次级绕组层S1的感应电压，以抑制次级绕组或者初级绕组产生的共模噪声，从而提高噪声抑制的性能。而与该第一噪声绕组层LB1串联的其它噪声抵消绕组层LB2的噪声抵消绕组线圈用于提高第一噪声绕组层LB1中噪声抵消绕组线圈的感应电压，因此，本申请中的第一噪声绕组层可以采用较少的线圈匝数就到达所需要的感应电压。
具体地，第一噪声抵消绕组中的第二噪声抵消绕组层的层数不限于一层，也可以是多层，第二噪声抵消绕组层的层数越多，第一噪声绕组层中噪声抵消绕组线圈的感应电压越高，进而可以使第一噪声绕组层中噪声抵消绕组线圈的匝数越少。
示例性的，如图8所示，初级绕组层(P)和次级绕组层(S)构成PS层叠层结构。第一噪声抵消绕组623包括噪声抵消绕组层LB1、噪声抵消绕组层LB2和噪声抵消绕组层LB3。噪声抵消绕组层LB1中的噪声抵消绕组的线圈的一个端头与噪声抵消绕组层LB2中的噪声抵消绕组的线圈的一个端头串联，噪声抵消绕组层LB2中的噪声抵消绕组的线圈的另一个端头与噪声抵消绕组层LB3中的噪声抵消绕组的线圈的一个端头串联，从而形成第一噪声抵消绕组623，形成的该第一噪声抵消绕组623会有两个端头，其中，第一噪声抵 消绕组623的第一端头用于连接电源转换电路的次级电路的电位静点或者用于连接电源转换电路的初级电路的电位静点，第一噪声抵消绕组623的第二端头悬空；第一噪声抵消绕组623的第二端头所在的噪声抵消绕组层LB1为第一噪声抵消绕组层，噪声抵消绕组层LB2和噪声抵消绕组层LB3均为第二噪声抵消绕组层，第一噪声抵消绕组层LB1设置于第一初级绕组层P1与第一次级绕组层S1之间，且分别与第一初级绕组层P1和第一次级绕组层S1相邻。
在上述实施例中，在平面变压器工作时，第一噪声抵消绕组623中的第一噪声抵消绕组层LB1中的噪声抵消绕组线圈的感应电压能够用于抵消或者补偿第一次级绕组层S1的感应电压，以抑制次级绕组或者初级绕组产生的共模噪声，从而提高噪声抑制的性能。而与该第一噪声绕组层LB1串联的其它噪声抵消绕组层LB2和LB3中的噪声抵消绕组线圈用于提高第一噪声绕组层LB1中噪声抵消绕组线圈的感应电压，因此，本申请中的第一噪声绕组层可以采用较少的线圈匝数就到达所需要的感应电压。并且，在相同条件下，要达到相同的感应电压，该实施例中第一噪声绕组层中线圈匝数比图7中第一噪声绕组层中线圈匝数更少。
可选地，在本申请中，当初级绕组和次级绕组设置为类似于“三明治”的夹层结构时，初级绕组和次级绕组会有两个相邻面，而初级绕组和次级绕组只要有相邻面，就可能产生共模噪声，因此，为了进一步抑制次级绕组或者初级绕组产生的共模噪声，从而提高噪声抑制的性能，可以在相邻设置的初级绕组和次级绕组之间均设置噪声抵消绕组。
例如，在本申请中，所述初级绕组还包括第二初级绕组层；所述次级绕组还包括第二次级绕组层；在所述第二初级绕组层与所述第二次级绕组层之间还设置有至少一层第二噪声抵消绕组层，其中，所述第二噪声抵消绕组层是指所述第一噪声抵消绕组中除了所述第一噪声抵消绕组层之外的其它噪声抵消绕组层。即利用所述第二噪声抵消绕组层中抵消绕组线圈的感应电压抵消或者补偿第二次级绕组层的感应电压，以进一步抑制次级绕组或者初级绕组产生的共模噪声，从而提高噪声抑制的性能。
示例性的，如图9所示，初级绕组层(P)和次级绕组层(S)构成SPS层叠层结构。第一噪声抵消绕组623包括噪声抵消绕组层LB1和噪声抵消绕组层LB2。噪声抵消绕组层LB1中的噪声抵消绕组的线圈的一个端头与噪声抵消绕组层LB2中的噪声抵消绕组的线圈的一个端头串联起来形成第一噪声抵消绕组623，形成的该第一噪声抵消绕组623会有两个端头，其中，第一噪声抵消绕组623的第一端头用于连接电源转换电路的次级电路的电位静点或者用于连接电源转换电路的初级电路的电位静点，第一噪声抵消绕组623的第二端头悬空；第一噪声抵消绕组623的第二端头所在的噪声抵消绕组层LB1为第一噪声抵消绕组层，噪声抵消绕组层LB2为第二噪声抵消绕组层，第一噪声抵消绕组层LB1设置于第一初级绕组层P1与第一次级绕组层S1之间，且分别与第一初级绕组层P1和第一次级绕组层S1相邻。第二噪声抵消绕组层LB2设置于第二初级绕组层P2与第二次级绕组层S2之间，且分别与第二初级绕组层P2和第二次级绕组层S2相邻。
在上述实施例中，在平面变压器工作时，第一噪声抵消绕组623中的第一噪声抵消绕组层LB1中的噪声抵消绕组线圈的感应电压能够用于抵消或者补偿第一次级绕组层S1的感应电压，以抑制次级绕组或者初级绕组产生的共模噪声，从而提高噪声抑制的性能。而与该第一噪声绕组层LB1串联的第二噪声抵消绕组层LB2中的噪声抵消绕组线圈用于提高第一噪声绕组层LB1中噪声抵消绕组线圈的感应电压，因此，本申请中的第一噪声绕组 层可以采用较少的线圈匝数就到达所需要的感应电压。并且第二噪声抵消绕组层LB2设置于第二初级绕组层P2与第二次级绕组层S2之间，利用所述第二噪声抵消绕组层LB2中抵消绕组线圈的感应电压抵消或者补偿第二次级绕组层的感应电压，以进一步抑制次级绕组或者初级绕组产生的共模噪声，从而提高噪声抑制的性能。
可选地，当所述第一噪声抵消绕组中包括多层第二噪声抵消绕组层时，在第二初级绕组层和第二次级绕组层之间可以仅设置一层第二噪声抵消绕组层，当然也可以设置多层第二噪声抵消绕组层，在此不作限定。
当在第二初级绕组层和第二次级绕组层之间仅设置一层第二噪声抵消绕组层时，可以将距离所述第一端头最远的噪声抵消绕组所在的所述第二噪声抵消绕组层设置于所述第二初级绕组层与所述第二次级绕组层之间，且分别与所述第二初级绕组层和所述第二次级绕组层相邻。这是因为，在所有的第二噪声抵消绕组层中，距离所述第一端头最远的噪声抵消绕组所在的所述第二噪声抵消绕组层，所述第二噪声抵消绕组层中噪声抵消绕组的感应电压相对最大，因此如若需要产生相同的感应电压，距离所述第一端头最远的噪声抵消绕组所在的所述第二噪声抵消绕组层中设置的线圈的匝数可以是最少的。当然，在具体实施时，也可以根据需要补偿或抵消的共模噪声的大小来确定需要设置在所述第二初级绕组层与所述第二次级绕组层之间的第二噪声抵消绕组层，例如，如果需要补偿或抵消的共模噪声较小，也可以将第一噪声抵消绕组的第一端头所在的第二噪声抵消绕组层设置在所述第二初级绕组层与所述第二次级绕组层之间，在此不作限定。
需要说明的是，第二噪声抵消绕组层分别与第二初级绕组层和第二次级绕组层相邻是指第二噪声抵消绕组层与第二初级绕组层之间不存在其他绕组层，以及第二噪声抵消绕组层与第二次级绕组层之间不存在其他绕组层。
示例性的，如图10所示，初级绕组层(P)和次级绕组层(S)构成SPS层叠层结构。第一噪声抵消绕组623包括噪声抵消绕组层LB1、噪声抵消绕组层LB2和噪声抵消绕组层LB3。噪声抵消绕组层LB1中的噪声抵消绕组的线圈的一个端头与噪声抵消绕组层LB2中的噪声抵消绕组的线圈的一个端头串联，噪声抵消绕组层LB2中的噪声抵消绕组的线圈的另一个端头与噪声抵消绕组层LB3中的噪声抵消绕组的线圈的一个端头串联，从而形成第一噪声抵消绕组623，形成的该第一噪声抵消绕组623会有两个端头，其中，第一噪声抵消绕组623的第一端头用于连接电源转换电路的次级电路的电位静点或者用于连接电源转换电路的初级电路的电位静点，第一噪声抵消绕组623的第二端头悬空；第一噪声抵消绕组623的第二端头所在的噪声抵消绕组层LB1为第一噪声抵消绕组层，噪声抵消绕组层LB2和噪声抵消绕组层LB3均为第二噪声抵消绕组层，第一噪声抵消绕组层LB1设置于第一初级绕组层S1与第一次级绕组层P1之间，且分别与第一初级绕组层S1和第一次级绕组层P1相邻。第二噪声抵消绕组层LB2设置于第二初级绕组层P2与第二次级绕组层S2之间，且分别与第二初级绕组层P2和第二次级绕组层S2相邻。
在上述实施例中，在平面变压器工作时，第一噪声抵消绕组623中的第一噪声抵消绕组层LB1中的噪声抵消绕组线圈的感应电压能够用于抵消或者补偿第一次级绕组层S1的感应电压，以抑制次级绕组或者初级绕组产生的共模噪声，从而提高噪声抑制的性能。而与该第一噪声绕组层LB1串联的第二噪声抵消绕组层LB2和LB3中的噪声抵消绕组线圈用于提高第一噪声绕组层LB1中噪声抵消绕组线圈的感应电压，因此，本申请中的第一噪声绕组层可以采用较少的线圈匝数就到达所需要的感应电压。第二噪声抵消绕组层LB2设 置于第二初级绕组层P2与第二次级绕组层S2之间，利用所述第二噪声抵消绕组层LB2中抵消绕组线圈的感应电压抵消或者补偿第二次级绕组层S2的感应电压，以进一步抑制次级绕组或者初级绕组产生的共模噪声，从而提高噪声抑制的性能。并且，与第二噪声绕组层LB2串联的第二噪声抵消绕组层LB3中的噪声抵消绕组线圈可以提高第二噪声绕组层LB2中噪声抵消绕组线圈的感应电压，同理，第二噪声绕组层LB2可以采用较少的线圈匝数就到达所需要的感应电压。
当在第二初级绕组层和第二次级绕组层之间设置有至少两层第二噪声抵消绕组层时，如果第一噪声抵消绕组的第一端头用于连接所述次级电路的电位静点，可以将距离所述第一端头最远的噪声抵消绕组所在的所述第二噪声抵消绕组层设置于所述第二初级绕组层与所述第二次级绕组层之间，且与所述第二初级绕组层相邻。如果所述第一噪声抵消绕组的第一端头用于连接所述初级电路的电位静点，可以将距离所述第一端头最远的噪声抵消绕组所在的所述第二噪声抵消绕组层设置于所述第二初级绕组层与所述第二次级绕组层之间，且与所述第二次级绕组层相邻。
示例性的，如图11所示，初级绕组层(P)和次级绕组层(S)构成PSP层叠层结构。第一噪声抵消绕组623包括噪声抵消绕组层LB1、噪声抵消绕组层LB2和噪声抵消绕组层LB3。噪声抵消绕组层LB1中的噪声抵消绕组的线圈的一个端头与噪声抵消绕组层LB2中的噪声抵消绕组的线圈的一个端头串联，噪声抵消绕组层LB2中的噪声抵消绕组的线圈的另一个端头与噪声抵消绕组层LB3中的噪声抵消绕组的线圈的一个端头串联，从而形成第一噪声抵消绕组623，形成的该第一噪声抵消绕组623会有两个端头，其中，第一噪声抵消绕组623的第一端头用于连接电源转换电路的次级电路的电位静点或者用于连接电源转换电路的初级电路的电位静点，第一噪声抵消绕组623的第二端头悬空；第一噪声抵消绕组623的第二端头所在的噪声抵消绕组层LB1为第一噪声抵消绕组层LB1，噪声抵消绕组层LB2和噪声抵消绕组层LB3均为第二噪声抵消绕组层，第一噪声抵消绕组层LB1设置于第一初级绕组层P1与第一次级绕组层SM之间，且分别与第一初级绕组层P1和第一次级绕组层S1相邻。第二噪声抵消绕组层LB2和LB3设置于第二初级绕组层P2与第二次级绕组层S2之间。
在上述实施例中，在平面变压器工作时，第一噪声抵消绕组623中的第一噪声抵消绕组层LB1中的噪声抵消绕组线圈的感应电压能够用于抵消或者补偿第一次级绕组层S1的感应电压，以抑制次级绕组或者初级绕组产生的共模噪声，从而提高噪声抑制的性能。而与该第一噪声绕组层LB1串联的第二噪声抵消绕组层LB2和LB3中的噪声抵消绕组线圈用于提高第一噪声绕组层LB1中噪声抵消绕组线圈的感应电压，因此，本申请中的第一噪声绕组层可以采用较少的线圈匝数就到达所需要的感应电压。第二噪声抵消绕组层LB2和LB3设置于第二初级绕组层P2与第二次级绕组层S2之间，利用所述第二噪声抵消绕组层LB2或LB3中抵消绕组线圈的感应电压抵消或者补偿第二次级绕组层S2的感应电压，以进一步抑制次级绕组或者初级绕组产生的共模噪声，从而提高噪声抑制的性能。
作为示例，以图7中第一噪声抵消绕组623包括两个噪声抵消绕组层LB1和LB2为例，其中噪声抵消绕组层LB1中的噪声抵消绕组线圈的一个端头悬空，噪声抵消绕组层LB1中线圈的另一个端头与噪声抵消绕组层LB2中噪声抵消绕组线圈的一个端头串联，噪声抵消绕组层LB2中噪声抵消绕组线圈的另一个端头与初级电路或者次级电路的电位静点连接，该第一噪声抵消绕组623的工作原理如下：
假设平面变压器中每一匝线圈的感应电压为V 0，噪声抵消绕组层LB1中的噪声抵消绕组相对相邻次级绕组的电容为Cc1，噪声抵消绕组层LB1中的噪声抵消绕组的线圈匝数为Nb1，噪声抵消绕组层LB1中的噪声抵消绕组相对相邻次级绕组的电容为Cc2，噪声抵消绕组层LB1中的噪声抵消绕组的匝数为Nb2。
现有技术中，两个噪声抵消绕组层是相互独立，且都是一端头接电位静点，一端头悬空。计算噪声抵消绕组产生的反向噪声电荷Q1：
噪声抵消绕组的平均感应电压：V1＝(0+Nb1*V 0)/2+(0+Nb2*V 0)/2＝V 0(Nb1+Nb2)/2；
反向噪声电流：i1＝c*dv/dt；
反向噪声电荷：Q1＝i1*t＝Cc1*Nb1*V 0/2+Cc2*Nb2*V 0/2；
基于本申请方案，计算电荷抵消绕组产生的反向噪声电荷Q2：
噪声抵消绕组的平均感应电压：V2＝(0+Nb1*V 0)/2+(Nb1*V 0+Nb2*V 0)/2＝V 0(2Nb1+Nb2)/2；
反向噪声电流：i2＝c*dv/dt；
反向噪声电荷：Q2＝i2*t＝Cc1*Nb1*V 0/2+Cc2*(Nb1*n+Nb2*V 0)/2；
在同样的噪声抵消绕组匝数配置的情况下，将本申请的串联结构的噪声抵消绕组与现有并联结构的噪声抵消绕组相比：
当Nb1＝Nb2＝Nb，Cc1＝Cc2＝Cc时，则有，
Q1＝Cc*Nb*n；
Q2＝Cc*Nb*n*3/2；
由此可以看出，本申请的噪声抵消绕组相比现有技术，在同样的噪声抵消绕组匝数配置情况下，产生的反向噪声电荷是现有技术的1.5倍。进而可以推导出，在产生同样大小的反向噪声电荷的情况下，本申请的噪声抵消绕组匝数可以减少50％。
进一步地，在本申请中，如图12至图14所示，第一噪声抵消绕组层LB1中的噪声抵消绕组的线圈匝宽大于第二噪声抵消绕组层LB2中的噪声抵消绕组的线圈匝宽。即第一噪声抵消绕组623的第二端头所在的噪声抵消绕组层中线圈匝宽设计的更宽，而相比之下，第一噪声抵消绕组623的第一端头所在的噪声抵消绕组层中线圈匝宽设计的更窄。这样可以进一步降低第一噪声抵消绕组的线圈匝数。下面结合原理说明上述实施例中的第一噪声抵消绕组的工作原理：
假设变压器中每一匝线圈的感应电压为V0。第一噪声抵消绕组的第一端头连接初级电路或次级电路的电位静点，与第一端头相连的第一匝线圈的电压为V0，从与第一端头相连的第一匝线圈起始，依次定义为第2匝线圈、第3匝线圈……第n匝线圈，由于每匝线圈是串联结构，所以第n匝线圈的感应电压为nV0。由此可得到越远离第一端头的线圈(或者说越靠近第二端头的匝)，其感应电压越高。这样，如果靠近第二端头的线圈的匝宽越大，则这部分噪声抵消绕组与相邻的次级绕组或初级绕组之间的寄生电容就越大，从而这部分噪声抵消绕组产生的反向噪声电荷就越多。因此，在噪声抵消绕组线圈匝数不变的情况下，增加线圈匝宽可以获得更多的反向噪声电荷。同理，在产生一定的反向噪声电荷的情况下，可以进一步的降低噪声抵消绕组的线圈匝数。
在一种可能的实现方式中，如图12所示，所述第一噪声抵消绕组层LB1中的噪声抵消绕组的线圈匝宽相同。
在一种可能的实现方式中，如图13所示，所述第一噪声抵消绕组层LB1中，离所述 第二端头越近的噪声抵消绕组的线圈，线圈匝宽越大。
可选地，在本申请中，如图14所示，所述PCB绕组板62还包括辅助绕组624，所述辅助绕组624可以设置于至少一层所述第二噪声抵消绕组层中。由于所述第二噪声抵消绕组层主要用于提升第一噪声抵消绕组层中线圈的感应电压，因此，将所述辅助绕组624设置于所述第二噪声抵消绕组层中不会影响第一噪声抵消绕组层。并且，可以减少PCB绕组板62中绕组的层数，提高平面变压器的空间利用率，从而节约平面变压器的成本。
在具体实施时，所述辅助绕组624可以是除了噪声抵消绕组之外的其它任意类型绕组，在此不作限定。
图15是本申请实施例的电源转换电路50与平面变压器60的连接关系示意图。如图15所示，初级电路51包括初级开关管511、初级滤波电容512、整流电路。次级电路52包括次级整流管521和次级滤波电容522。初级滤波电容512和次级滤波电容522可以采用电解电容。通常情况下，与初级滤波电容512的两端中的任意一端相连的节点为初级电路的电位静点，或者，初级电路的地节点也可以为初级电路的电位静点。与次级滤波电容522的两端中的任意一端相连的节点为次级电路的电位静点。
如图15所示，初级绕组621的一端用于与电源转换电路50的初级电位静点相连。上述次级绕组622的一端用于与电源转换电路的次级电位静点相连。例如，初级绕组621的两端可以分别与初级开关管511以及初级滤波电容512相连，次级绕组622的两端分别与次级整流管521以及次级滤波电容522相连。上述第一噪声抵消绕组623的第一端头用于与电源转换电路50的初级电路的电位静点或者次级电路的电位静电相连，上述第一噪声抵消绕组623的第二端头可以悬空。其中，上述悬空可以指第一噪声抵消绕组623的第二端头与任何导体之间不存在电性连接，且与任何元件之间不存在电性连接。例如，第一噪声抵消绕组623的第一端可以与初级滤波电容512相连。
参照图16，本申请实施例还提供了一种适配器100，该适配器100可以包括外壳101，以及设置于该外壳101内的电源转换电路50。由于该适配器解决问题的原理与前述一种电源转换电路相似，因此该适配器的实施可以参见前述电源转换电路的实施，重复之处不再赘述。
本申请实施例提供的上述平面变压器、电源转换电路及适配器，在平面变压器的初级绕组和次级绕组之间设置第一噪声抵消绕组，并且通过设计第一噪声抵消绕组中各噪声抵消绕组层的线圈匝数，以使得在所述平面变压器工作时，所述第一噪声抵消绕组层中的噪声抵消绕组线圈的感应电压能够用于抵消或者补偿第一次级绕组层的感应电压，以抑制次级绕组或者初级绕组产生的共模噪声，从而提高噪声抑制的性能。并且，由于第一噪声抵消绕组由至少两个噪声抵消绕组层中的噪声抵消绕组的线圈依次串联形成，而设置于第一初级绕组层和第一次级绕组层之间的第一噪声绕组层是所述第一噪声抵消绕组的第二端头所在的噪声抵消绕组层，这样利用所述第一噪声抵消绕组中与该第一噪声绕组层串联的其它噪声抵消绕组层的噪声抵消绕组线圈来提高第一噪声绕组层中噪声抵消绕组线圈的感应电压，因此与现有技术相比，本申请中的第一噪声绕组层可以采用较少的线圈匝数就到达所需要的感应电压。
本领域普通技术人员可以意识到，结合本文中所公开的实施例描述的各示例的单元及算法步骤，能够以电子硬件、或者计算机软件和电子硬件的结合来实现。这些功能究竟以硬件还是软件方式来执行，取决于技术方案的特定应用和设计约束条件。专业技术人员可 以对每个特定的应用来使用不同方法来实现所描述的功能，但是这种实现不应认为超出本申请的范围。
所属领域的技术人员可以清楚地了解到，为描述的方便和简洁，上述描述的系统、装置和单元的具体工作过程，可以参考前述方法实施例中的对应过程，在此不再赘述。
在本申请所提供的几个实施例中，应该理解到，所揭露的系统、装置和方法，可以通过其它的方式实现。例如，以上所描述的装置实施例仅仅是示意性的，例如，所述单元的划分，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式，例如多个单元或组件可以结合或者可以集成到另一个系统，或一些特征可以忽略，或不执行。另一点，所显示或讨论的相互之间的耦合或直接耦合或通信连接可以是通过一些接口，装置或单元的间接耦合或通信连接，可以是电性，机械或其它的形式。
所述作为分离部件说明的单元可以是或者也可以不是物理上分开的，作为单元显示的部件可以是或者也可以不是物理单元，即可以位于一个地方，或者也可以分布到多个网络单元上。可以根据实际的需要选择其中的部分或者全部单元来实现本实施例方案的目的。
另外，在本申请各个实施例中的各功能单元可以集成在一个处理单元中，也可以是各个单元单独物理存在，也可以两个或两个以上单元集成在一个单元中。
以上，仅为本申请的具体实施方式，但本申请的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本申请揭露的技术范围内，可轻易想到变化或替换，都应涵盖在本申请的保护范围之内。因此，本申请的保护范围应以权利要求的保护范围为准。

Claims (12)

  1. 一种平面变压器，其特征在于，包括磁芯和印刷电路板PCB绕组板，其中所述PCB绕组板包括：
    初级绕组，包括第一初级绕组层；
    次级绕组，包括第一次级绕组层；
    第一噪声抵消绕组，包括至少两个噪声抵消绕组层，且所述至少两个噪声抵消绕组层中的噪声抵消绕组的线圈依次串联形成所述第一噪声抵消绕组；
    所述第一噪声抵消绕组的第一端头用于连接电源转换电路的次级电路的电位静点或者用于连接所述电源转换电路的初级电路的电位静点，所述第一噪声抵消绕组的第二端头悬空；
    所述第一噪声抵消绕组的第二端头所在的所述噪声抵消绕组层为第一噪声抵消绕组层，所述第一噪声抵消绕组层设置于所述第一初级绕组层与所述第一次级绕组层之间，且当所述第一噪声抵消绕组的第一端头用于连接所述次级电路的电位静点时，所述第一噪声抵消绕组层与所述第一初级绕组层相邻，当所述第一噪声抵消绕组的第一端头用于连接所述初级电路的电位静点时，所述第一噪声抵消绕组层与所述第一次级绕组层相邻。
  2. 如权利要求1所述的平面变压器，其特征在于，所述第一噪声抵消绕组中除了所述第一噪声抵消绕组层之外的其它噪声抵消绕组层为第二噪声抵消绕组层。
  3. 如权利要求2所述的平面变压器，其特征在于，所述初级绕组还包括第二初级绕组层；
    所述次级绕组还包括第二次级绕组层；
    至少一层所述第二噪声抵消绕组层设置于所述第二初级绕组层与所述第二次级绕组层之间。
  4. 如权利要求3所述的平面变压器，其特征在于，距离所述第一端头最远的噪声抵消绕组所在的所述第二噪声抵消绕组层设置于所述第二初级绕组层与所述第二次级绕组层之间，且分别与所述第二初级绕组层和所述第二次级绕组层相邻。
  5. 如权利要求3所述的平面变压器，其特征在于，所述第一端头所在的所述第二噪声抵消绕组层设置于所述第二初级绕组层与所述第二次级绕组层之间，且分别与所述第二初级绕组层和所述第二次级绕组层相邻。
  6. 如权利要求2～5任一项所述的平面变压器，其特征在于，所述第一噪声抵消绕组层中的噪声抵消绕组的线圈匝宽大于所述第二噪声抵消绕组层中的噪声抵消绕组的线圈匝宽。
  7. 如权利要求6所述的平面变压器，其特征在于，所述第一噪声抵消绕组层中的噪声抵消绕组的线圈匝宽相同。
  8. 如权利要求6所述的平面变压器，其特征在于，所述第一噪声抵消绕组层中，离所述第二端头越近的噪声抵消绕组的线圈，线圈匝宽越大。
  9. 如权利要求2～5任一项所述的平面变压器，其特征在于，所述PCB绕组板还包括辅助绕组，所述辅助绕组设置于至少一层所述第二噪声抵消绕组层上。
  10. 如权利要求1～5任一项所述的平面变压器，其特征在于，所述初级绕组设置于所述次级绕组的两侧，或者，所述次级绕组设置于所述初级绕组的两侧。
  11. 一种电源转换电路，其特征在于，包括：初级电路、次级电路以及如权利要求1～10中任一项所述的平面变压器，所述平面变压器设置在所述初级电路和所述次级电路之间。
  12. 一种适配器，其特征在于，包括外壳和如权利要求11所述的电源转换电路，其中，所述电源转换电路设置于所述外壳内。
PCT/CN2021/103099 2020-10-28 2021-06-29 平面变压器、电源转换电路及适配器 WO2022088728A1 (zh)

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