WO2019091393A1 - 平面变压器、电源转换电路以及适配器 - Google Patents

平面变压器、电源转换电路以及适配器 Download PDF

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Publication number
WO2019091393A1
WO2019091393A1 PCT/CN2018/114303 CN2018114303W WO2019091393A1 WO 2019091393 A1 WO2019091393 A1 WO 2019091393A1 CN 2018114303 W CN2018114303 W CN 2018114303W WO 2019091393 A1 WO2019091393 A1 WO 2019091393A1
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Prior art keywords
winding
primary
coil
winding layer
charge balancing
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PCT/CN2018/114303
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English (en)
French (fr)
Inventor
余鹏
陈为
任杰
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华为技术有限公司
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Priority to EP18875584.7A priority Critical patent/EP3696831B1/en
Publication of WO2019091393A1 publication Critical patent/WO2019091393A1/zh
Priority to US16/871,145 priority patent/US11062837B2/en

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    • 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
    • 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
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/003—Constructional details, e.g. physical layout, assembly, wiring or busbar 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
    • H02M1/44—Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
    • 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
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • 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
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • 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
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/33507—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters
    • 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
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/33569—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements
    • H02M3/33576—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements having at least one active switching element at the secondary side of an isolation transformer
    • 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 circuits and, more particularly, to a planar transformer, a power conversion circuit, and an adapter.
  • Switching power supplies are rapidly developed with their advantages of high efficiency, small size, and good output stability.
  • the electromagnetic interference problem during the operation 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 the self-switching device, the recovery of the rectifier diode, and the noise generated by the capacitor/inductor/wire. These noise signals are transmitted and radiated to the electrical equipment along the circuit network. , causing electromagnetic interference. Therefore, the switching power supply has strict requirements on noise suppression.
  • the noise of the switching power supply is divided into differential mode noise and common mode noise, and the differential mode noise mainly includes noise caused by the ripple current of the switching converter.
  • the common mode noise mainly includes the noise between the reference ground generated by the interaction between the parameters of the switching power supply circuit. How to reduce or even eliminate the noise of the switching power supply is a problem of great concern in the industry.
  • the application provides a planar transformer, a power conversion circuit and an adapter, which can improve the performance of noise suppression.
  • a planar transformer comprising: a primary winding comprising a first primary winding layer; a secondary winding comprising a first secondary winding layer, the secondary being disposed on the first secondary winding layer
  • a charge balancing winding comprising a first charge balancing winding layer, the first charge balancing winding layer being disposed between the first primary winding layer and the first secondary winding layer, and the first a primary winding layer adjacent to the first secondary winding layer, a first end of the first charge balancing winding layer for connecting a potential dead spot of a primary circuit of the power conversion circuit, the first charge balancing winding
  • An N 1 ⁇ coil is disposed on the layer, wherein N 1 is greater than
  • a charge balancing winding is disposed between a primary winding and a secondary winding of the planar transformer, and by designing a number of coil turns of the first charge balancing winding layer included in the charge balancing winding, such that the planar transformer is In operation, an induced voltage of at least a portion of the coils in the first charge balancing winding layer can be used to balance an induced voltage of the first secondary winding layer to suppress common mode noise generated by the secondary winding, thereby improving noise suppression performance .
  • the primary winding potential jump is coupled to the second gap through the charge balance winding The noise current of the secondary winding.
  • the value range of C 1 is [0, 1.1 * N b1 ].
  • the primary winding further includes a second primary winding layer;
  • the secondary winding further includes a second secondary winding layer, and the secondary is disposed on the second secondary winding layer a Nth s2 ⁇ to Nth s2 + B 2 -1 ⁇ coil of the winding, wherein N s2 , B 2 are positive numbers;
  • the charge balancing winding further includes a second charge balancing winding layer, the second charge balancing winding a layer disposed between the second primary winding layer and the second secondary winding layer and adjacent to the second primary winding layer and the second secondary winding layer, the second charge balancing winding a first end of the layer is used to connect a potential static point of the primary circuit of the power conversion circuit, and a second N 2 ⁇ coil is disposed on the second charge balancing winding layer, wherein N 2 is greater than or equal to N b2 at the plane When the transformer is in operation, the average value of the third induced voltage generated by the N b2 coil is equal to the first
  • a charge balancing winding is disposed between the primary winding and the secondary winding of the planar transformer, the charge balancing winding includes a first charge balancing winding layer and a second charge balancing winding layer, and the coil of the charge balancing winding is designed a number of turns such that when the planar transformer is operating, an induced voltage of at least a portion of the coils in the charge balancing winding can be used to balance an induced voltage of the secondary winding to suppress common mode noise generated by the secondary winding, Thereby improving the performance of noise suppression.
  • C 2 has a value range of [0, 1.1 * N b2 ].
  • the primary winding includes a primary power winding, and the first end of the first charge balancing winding layer and the first end of the primary power winding are the same end, wherein A first end of the primary power winding is used to connect the moving point of the primary circuit.
  • the induced current direction generated by the first charge balancing winding layer is generated by the primary winding
  • the direction of the ground noise current is opposite, thereby suppressing the ground noise current generated by the primary winding and improving the noise suppression performance of the power conversion circuit.
  • the auxiliary power winding comprises a primary winding, a 1 N turn coils disposed on said first layer is a charge balancing winding of the auxiliary power supply to the first winding turn to one turn of N a coil, wherein the first turn of the auxiliary power winding is used to connect the working ground of the primary circuit.
  • a charge balancing winding is disposed in the planar transformer, and the auxiliary power winding can be used as the charge balancing winding to suppress the noise in the power conversion circuit, and the volume of the planar transformer is reduced, thereby saving manufacturing cost.
  • the primary windings are disposed on two sides of the secondary winding, or the secondary windings are disposed on both sides of the primary winding.
  • B 1 1.
  • the N 1 ⁇ coil in the first charge balancing winding layer forms a ring winding
  • the ⁇ width of the ith coil in the ring winding is greater than that of the ith +1 ⁇ coil
  • the width of the ith coil is smaller than the average radius of the (i+1)th coil, and N 1 -1 ⁇ i ⁇ 1 .
  • the coils of the charge balance winding layer are successively smaller along the inner and outer diameters of the inner and outer diameters, so that the capacitance between the charge balance winding layer and the adjacent secondary winding layer is evenly distributed, thereby improving noise suppression. performance.
  • R i is the average radius of the ith coil
  • R i+1 is the average radius of the ith +1 ⁇ coil
  • a i is the ⁇ width of the ith coil
  • a i+1 is The width of the ith i+1 turns coil.
  • the toroidal winding by setting the width of each of the coils of the charge balance winding layer along the inner and outer diameters so that the areas of the turns are equal, thereby making the charge balance winding layer and the adjacent secondary winding
  • the capacitance between the layers is evenly distributed, which can improve the performance of noise suppression.
  • a power conversion circuit comprising: the planar transformer, the primary circuit, and the secondary circuit as described in the first aspect or any of the possible implementations of the first aspect, the planar transformer setting Between the primary circuit and the secondary circuit.
  • an adapter comprising the power conversion circuit of the second aspect.
  • FIG. 1 is a schematic diagram of a possible application scenario of an embodiment of the present application.
  • FIG. 2 is a schematic diagram of a power conversion circuit of an embodiment of the present application.
  • FIG. 3 is a schematic diagram of a power conversion circuit according to still another embodiment of the present application.
  • FIG. 4 is a schematic diagram of a method for noise suppression according to an embodiment of the present application.
  • FIG. 5 is a schematic diagram of a power conversion circuit according to still another embodiment of the present application.
  • 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 in accordance with still another embodiment of the present application.
  • FIG. 8 is a schematic diagram showing a connection relationship between a power conversion circuit and a planar transformer according to an embodiment of the present application.
  • FIG. 9 is a schematic diagram showing the principle of suppressing common mode noise by the power conversion circuit of the embodiment of the present application.
  • FIG. 10 is a schematic diagram of a noise path of a ground fault current of a power conversion circuit according to an 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 view showing the potential distribution of the coil of the secondary winding layer of the embodiment of the present application.
  • FIG. 13 is a schematic view showing a potential distribution of a coil of a secondary winding layer in a circumferential direction according to still another embodiment of the present application.
  • Figure 14 is a schematic cross-sectional view of a planar transformer in accordance with another embodiment of the present application.
  • Figure 15 is a schematic cross-sectional view of a planar transformer in accordance with another embodiment of the present application.
  • Figure 16 is a cross-sectional view showing a planar transformer of another embodiment of the present application.
  • Planar transformer Different from the traditional transformer structure, the core and winding of the planar transformer are planar structures.
  • the magnetic core generally adopts a small-sized E-type and RM-type magnetic core structure, and the winding is generally formed by stacking a printed circuit board (PCB).
  • PCB printed circuit board
  • Flyback converter widely used in AC/DC and DC/DC conversion. It is a relatively common low-power switching power converter with the advantages of simple structure and low cost. Its core components include power switching tubes, transformers, diodes and capacitors. The power switch tube is controlled by pulse width modulation, and generates a high frequency square wave signal in the primary coil of the transformer through closing and conducting, and then inductively couples to the secondary coil of the transformer to realize energy transfer. A stable DC output is obtained at the output through the filter rectification of the diodes and capacitors of the secondary circuit.
  • Common mode noise also known as asymmetric noise or line-to-ground noise, is present in electrical equipment that uses AC power.
  • the common mode noise current flows in the same direction on both power lines and The phase to ground remains the same and returns through the ground.
  • Common mode noise can be suppressed by using a Y-capacitor between the common mode inductor or between the two power lines and ground.
  • Differential mode noise is also called normal type, symmetrical noise or inter-line noise. It exists in AC lines and neutral conductors, and the phase difference is 180°. The current of the differential mode noise flows along an AC line and returns along the other AC line, and there is no differential mode noise current in the ground line.
  • Potential static point In a circuit network, the voltage potential amplitude on the network node remains relatively constant during the operation of the circuit, without high frequency jumps or oscillations.
  • the filter capacitor after rectification of the primary side circuit of the flyback converter and the filter capacitor after rectification of the secondary side circuit, the positive or negative pole of these capacitors and the network node directly connected thereto are potential static points.
  • the moving point of the primary circuit can refer to a circuit node or network with a voltage jump on the primary side of the circuit topology as the primary switching transistor is turned on and off, such as a node where the primary power winding is connected to the switching transistor.
  • Winding layer In a planar transformer, the winding layer refers to a multi-turn coil that is in the same plane in the winding. The plane is perpendicular to the central axis of the core surrounded by the windings, and the multi-turn coils may be wound in parallel on the same plane from the inside to the outside. In one winding, there may be multiple winding layers, the planes of each winding layer being parallel to one another, perpendicular to the central axis of the core. Correspondingly, two adjacent winding layers, ie two planes, are parallel, and there are no two winding layers of the other winding layer in between.
  • the application provides a planar transformer, a power conversion circuit, and an adapter.
  • the planar transformer may be disposed in a power conversion circuit
  • the power conversion circuit may be disposed in an adapter.
  • FIG. 1 shows a possible application scenario of an embodiment of the present application.
  • the application scenario includes an external power source 11, an adapter 12, and a device to be charged 13.
  • the device to be charged 13 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 coupled to an external power source 11 that includes a power conversion circuit for converting the higher voltage provided by the external power source 11 to a lower voltage that meets the charging or powering criteria of the device 13 to be charged, and is The charging device 13 performs charging or power supply.
  • the planar transformer provided by the embodiment of the present application is capable of reducing noise generated during operation.
  • the above noise can include common mode noise.
  • the above noise may include differential mode noise.
  • the power conversion circuit may be a switching power converter.
  • the switching power converter may include the flyback converter described above.
  • the noise of the switching power supply is divided into differential mode noise and common mode noise, and the differential mode noise is mainly caused by the ripple current of the switching converter, and can be suppressed by a filter.
  • the common mode noise is mainly caused by the interaction between the parameters of the switching power supply circuit and the reference ground. The mechanism of common mode noise generation and transmission in the power conversion circuit 20 will be described below with reference to FIGS. 2 and 3.
  • the power conversion circuit 20 generally includes a primary circuit 21, a secondary circuit 22, and a transformer 23.
  • the primary circuit typically includes a primary switching transistor 211 and a primary filtering capacitor 212. Further, the primary circuit further includes a rectifier circuit.
  • the primary switching transistor 211 described above may also be referred to as a power switching transistor.
  • Secondary circuit 22 typically includes a secondary rectifier 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 coupled to the primary switching transistor 211 and the primary filter capacitor 212, and the secondary winding 232 can be coupled to the secondary rectifier 221 and the secondary filter capacitor 222.
  • the primary filter capacitor 212 and the secondary filter capacitor 222 typically employ electrolytic capacitors.
  • the node connected to either end of the primary filter capacitor 212 is the potential dead point of the primary circuit, or the ground node of the primary circuit can also be the potential dead point of the primary circuit.
  • the node connected to either end of the secondary filter capacitor 222 is the potential dead point of the secondary circuit.
  • the potential static point of the primary circuit may also be referred to as a primary potential static point
  • the potential static point of the secondary circuit may also be referred to as a secondary potential static point.
  • the alternating current input from the external power source 11 is converted into a stable high voltage direct current input to the primary winding 231 of the transformer 23 after being rectified and filtered by the primary circuit 21.
  • the primary switching transistor 211 connected to the primary winding 231 couples the voltage on the primary winding 231 to the secondary winding 232 by high frequency conduction and turn-off. After the voltage coupled to the secondary winding 232 is rectified by the secondary circuit 22, a low voltage direct current is output to the load to charge or power the load.
  • the above load is the above-mentioned device 13 to be charged.
  • the primary switching transistor 211 and the secondary rectifier 221 generate trip voltages Vp and Vs, respectively, due to high frequency conduction and turn-off. Due to the parasitic capacitance between the primary winding 231 and the secondary winding 232 of the transformer, the hopping voltages Vp and Vs generate common mode noise in the power conversion circuit through the above parasitic capacitance.
  • the parasitic capacitance described above includes a distributed capacitance Cps between the primary winding and the secondary winding and a distributed capacitance Csp of the secondary winding to the primary winding.
  • the hopping voltage Vp in the primary circuit generates a noise current Ips flowing to the ground through Cps
  • the hopping voltage Vs in the secondary circuit generates a noise current Isp flowing to the ground through Csp.
  • the above noise current Ips and noise current Isp are common mode noise.
  • a Line Impedance Stabilization Network (LISN) circuit is also illustrated.
  • the LISN circuit is a test circuit for detecting a common mode noise current flowing into the ground when the power conversion circuit operates. In other words, it can be considered that the current to the ground 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 of suppressing noise according to the related art.
  • a shield shielding method may be employed.
  • the shield 31 is statically connected to the primary potential and wraps the primary winding 231 to shield the primary trip voltage Vp from the secondary winding 232.
  • a Y capacitor can be provided between the primary circuit and the secondary circuit of the power conversion circuit 20. Both ends of the Y capacitor can be connected to the primary potential static point and the secondary potential static point, respectively.
  • the above connection method is equivalent to the Y capacitor being connected in parallel to both sides of the LISN, so that the common mode noise originally passed through the LISN is shunted through the Y capacitor branch, thereby reducing the noise current detected by the LISN.
  • the above-mentioned shielding body 31 cannot eliminate the noise sources Vp and Vs from the source, and the increased Y capacitance not only causes cost increase and volume increase, but also brings power frequency leakage current between the primary circuit 21 and the secondary circuit 22. , bringing leakage safety risks.
  • the embodiment of the present application provides a planar transformer, a power conversion circuit, and an adapter, which can provide a solution for improving the noise suppression performance of the power conversion circuit. Further, since the common mode noise can be sufficiently suppressed, the power conversion circuit in the embodiment of the present application can cancel the Y capacitor across the primary circuit and the secondary circuit, thereby providing a safer power supply without a Y capacitor. Conversion circuit.
  • the power conversion circuit 50 of the embodiment of the present application will be described in detail below with reference to the accompanying drawings.
  • the above power conversion circuit 50 can be applied to an adapter.
  • the above-described power conversion circuit 50 includes a primary circuit 51, a secondary circuit 52, and a planar transformer 53.
  • FIG. 5 is a schematic diagram of a power conversion circuit 50 of an embodiment of the present application.
  • the above-described power conversion circuit 50 includes a primary circuit 51, a secondary circuit 52, and a planar transformer 60.
  • the structure of the primary circuit 51 is the same as or similar to that of the primary circuit 21 in FIG.
  • the secondary circuit 52 is the same as or similar to the secondary circuit 22 of FIG. 2 and will not be described again here.
  • the planar transformer 60 will be described.
  • FIG. 6 shows a schematic structural view of a planar transformer 60 according to an embodiment of the present application.
  • the planar transformer 60 includes a primary winding 61, a secondary winding 62, and a charge balancing winding 63.
  • the planar transformer 60 can also include a magnetic core 64.
  • the material of the magnetic core 64 is not limited in the embodiment of the present application.
  • the magnetic core 64 may be of an EE type, an EI type, or an RM type.
  • the bobbin of the magnetic core 64 may be provided with the primary winding 61, the secondary winding 62, and the charge balancing winding 63 composed of a plurality of circuit boards.
  • FIG. 7 is a schematic cross-sectional view of a planar transformer 60 in accordance with an embodiment of the present application.
  • the above primary winding 61 may include at least one primary winding layer.
  • Each of the primary winding layers included in the primary winding 61 can be represented by P1, P2, ..., Pn.
  • P is used to indicate each primary winding layer in FIG.
  • FIG. 7 shows a half cross-sectional view of the planar transformer 60.
  • FIG. 11 and FIG. 14 to FIG. 15 below show a half cross-sectional view of a planar transformer.
  • the primary winding 61 may include a primary power winding, and further, the primary winding 61 may further include an auxiliary power winding.
  • the auxiliary power supply winding may refer to a winding that provides a small power supply for other circuits than the main power circuit in the power conversion circuit.
  • Other circuits than the main power circuit described above may include, for example, circuits for driving, controlling, detecting, and the like.
  • the at least one primary winding layer may be provided with a coil of a primary power winding or, alternatively, a coil of an auxiliary power winding.
  • the above coils may be constructed using a conductive layer.
  • the coils of the primary power winding described above are connected in series.
  • the primary winding 61 described above may include a first primary winding layer. At least a portion of the coils of the primary power winding may be disposed on the first primary winding layer, or at least a portion of the coils of the auxiliary power winding may be disposed.
  • the secondary winding 62 described above may include at least one secondary winding layer.
  • Each of the secondary winding layers included in the secondary winding 62 can be represented by S1, S2, ..., Sn. Similar to the primary winding 61, the coils provided on the at least one secondary winding layer are connected in series with each other.
  • the secondary winding 62 described above may include a first secondary winding layer.
  • the charge balancing winding 63 described above may include at least one charge balancing winding layer.
  • the at least one charge balancing winding layer may be represented by B1, B2 or the like.
  • the charge balancing winding layer will be described below by taking at least one charge balancing winding layer including the first charge balancing winding layer as an example.
  • the first charge balancing winding layer may be any one of the at least one charge balancing winding layer described above.
  • the first charge balancing winding layer may be disposed between the first primary winding layer and the first secondary winding layer and adjacent to the first primary winding layer and the first secondary winding layer.
  • the first secondary winding layer is provided with an Nth s1 ⁇ to Nth s1 + B 1 -1 ⁇ coil of the secondary winding, wherein the first winding of the secondary winding is used for connecting a power conversion circuit
  • the potential of the secondary circuit is static, and N s1 and B 1 are positive numbers.
  • N 1 is greater than or equal to N b1
  • an average value of the first induced voltage generated by the N b1 ⁇ coil is equal to an average value of the second induced voltage generated by the first secondary winding layer when the planar transformer operates
  • N 1 and N b1 are positive numbers.
  • first charge balancing winding layer adjacent to the first primary winding layer and the first secondary winding layer means that there is no other winding layer between the first charge balancing winding layer and the first primary winding layer, and the first There are also no other winding layers between the charge balancing winding layer and the first secondary winding layer.
  • a charge balancing winding is disposed between a primary winding and a secondary winding of the planar transformer, and by designing a number of coil turns of the first charge balancing winding layer included in the charge balancing winding, such that the planar transformer is In operation, an induced voltage of at least a portion of the coils in the first charge balancing winding layer can be used to balance an induced voltage of the first secondary winding layer to suppress common mode noise generated by the secondary winding, thereby improving noise suppression performance .
  • the power conversion circuit in the embodiment of the present application can cancel the Y capacitor across the primary circuit and the secondary circuit, thereby providing a safer power supply without a Y capacitor. Conversion circuit.
  • the at least one charge balancing winding may further include a second charge balancing winding layer, the second charge balancing winding layer being similar to the setting of the first charge balancing winding layer.
  • the primary winding 61 described above further includes a second primary winding layer
  • the secondary winding 62 further includes a second secondary winding layer on which the Nth of the secondary winding is disposed S2 ⁇ to an Nth s2 + B 2 -1 ⁇ coil, wherein N s2 and B 2 are positive numbers
  • the charge balancing winding 63 further includes a second charge balancing winding layer, and the second charge balancing winding layer is disposed on Between the second primary winding layer and the second secondary winding layer, adjacent to the second primary winding layer and the second secondary winding layer, the second charge balancing winding layer One end is for connecting a potential static point of the primary circuit of the power conversion circuit, and the second charge balancing winding layer is provided with an N 2 ⁇ coil, wherein N 2 is greater than
  • the second charge balancing winding layer adjacent to the second primary winding layer and the second secondary winding layer means that there is no other winding layer between the second charge balancing winding layer and the second primary winding layer, and the second There are also no other winding layers between the charge balancing winding layer and the second secondary winding layer.
  • a charge balancing winding is disposed between the primary winding and the secondary winding of the planar transformer, the charge balancing winding includes a first charge balancing winding layer and a second charge balancing winding layer, and the coil of the charge balancing winding is designed a number of turns such that when the planar transformer is operating, an induced voltage of at least a portion of the coils in the charge balancing winding can be used to balance an induced voltage of the secondary winding to suppress common mode noise generated by the secondary winding, Thereby improving the performance of noise suppression.
  • N 1 can also enable the induced current generated by the charge balancing winding to be used to cancel the ground noise current generated by the primary winding, thereby further improving the performance of noise suppression.
  • N 1 or N 2 a detailed description will be given later with reference to FIGS. 9 and 10.
  • the primary winding 61 includes a primary power winding, the first end of the first charge balancing winding layer and the first end of the primary power winding being the same end, wherein the primary power winding The first end is for connecting the moving point of the primary circuit.
  • the direction of the induced current generated by the first charge balancing winding layer is opposite to the direction of the ground noise current generated by the primary winding, thereby suppressing the ground noise current generated by the primary winding.
  • the moving point of the primary circuit may refer to a circuit node or network having a voltage jump with the primary switching transistor being turned on and off on the primary side of the circuit topology, such as a node connecting the primary power winding and the primary switching transistor;
  • the induced current direction generated by the first charge balancing winding layer is generated by the primary winding
  • the direction of the ground noise current is opposite, thereby suppressing the ground noise current generated by the primary winding and improving the noise suppression performance of the power conversion circuit.
  • FIG. 8 is a schematic diagram showing the connection relationship between the power conversion circuit 50 and the planar transformer 60 in the embodiment of the present application.
  • the primary circuit 51 includes a primary switching transistor 511, a primary filter capacitor 512, and a rectifier circuit.
  • the secondary circuit 52 includes a secondary rectifier 521 and a secondary filter capacitor 522.
  • the primary filter capacitor 212 and the secondary filter capacitor 222 may employ electrolytic capacitors.
  • the node connected to either end of the primary filter capacitor 212 is the primary potential dead point, or the ground node of the primary circuit can also be the primary potential dead point.
  • the node connected to either end of the secondary filter capacitor 222 is a secondary potential dead point.
  • one end of the primary winding 61 is used to be connected to the primary potential dead point of the power conversion circuit 50.
  • One end of the secondary winding 62 described above is used to be connected to the secondary potential of the power conversion circuit.
  • both ends of the primary winding 61 may be connected to the primary switching transistor 511 and the primary filter capacitor 512, respectively, and the two ends of the secondary winding 62 are respectively connected to the secondary rectifier 521 and the secondary filter capacitor 522.
  • One end of the above-described charge balancing winding 63 is connected to the primary potential dead point of the power conversion circuit 50, and the other end of the above-described charge balancing winding can be suspended.
  • the above floating space may mean that there is no electrical connection between the other end of the charge balancing winding and any conductor, and there is no electrical connection with any component.
  • one end of the charge balancing winding 63 can be connected to the primary filter capacitor 512.
  • the charge balancing winding 63 as an example of the first charge balancing winding layer, the first end of the N 1 ⁇ coil of the first charge balancing winding layer is connected to the primary potential static point, the first charge balancing winding
  • the second end of the N 1 turns coil can be suspended, that is, there is no electrical connection to any conductor or component.
  • the auxiliary power winding can be utilized in place of the first charge balancing winding.
  • one end of the auxiliary power supply winding is connected to the primary potential static point, assuming that the first one of the auxiliary power supply windings is connected to the primary potential dead point.
  • the N 1 ⁇ coil disposed on the first charge balancing winding layer may be the first ⁇ to N 1 ⁇ coil of the auxiliary power winding.
  • the auxiliary power supply winding includes a P ⁇ coil and P is greater than N 1
  • the N 1 +1 ⁇ to P ⁇ coils in the auxiliary power winding may be disposed on at least one primary winding layer included in the primary winding. in.
  • a charge balancing winding is disposed in the planar transformer, and the auxiliary power winding can be used as the charge balancing winding to suppress the noise in the power conversion circuit, and the volume of the planar transformer is reduced, thereby saving manufacturing cost.
  • one end of the first charge balancing winding layer needs to be connected to the primary potential static point, and the other end of the first charge balancing winding layer may be suspended or connected to other potential nodes.
  • the coil of the first charge balancing winding layer is at least part of the auxiliary power winding
  • one end of the first charge balancing winding layer is connected to the primary potential static point, and the first charge balancing winding layer is further One end may not be suspended, but may be connected to the N 1 +1 ⁇ coil in the auxiliary power winding.
  • the relative positions of the primary winding and the secondary winding described above may include at least the following three forms.
  • the primary windings may be disposed on both sides of the secondary winding, that is, a part of the primary winding layers in the primary windings are disposed on one side of the secondary winding, and the primary is Another portion of the primary winding layer of the winding is disposed on the other side of the secondary winding to form a sandwich structure similar to a "sandwich".
  • the above-mentioned "sandwich" structure can reduce the high frequency eddy current loss and leakage inductance of the winding.
  • the secondary windings may also be placed on either side of the primary winding.
  • all of the primary winding layers included in the primary winding may be located on one side of all of the secondary winding layers included in the secondary winding.
  • the charge balancing winding may include two charge balancing winding layers and are respectively disposed adjacent to the primary Between the winding layer and the secondary winding layer.
  • the charge balancing winding may include a charge balance winding layer.
  • the common mode noise current generated by the hopping voltage Vp of the primary winding 61 can be shielded.
  • the common mode current generated by the potential of the charge balancing winding 63 and the noise charge generated by the potential of the secondary winding 62 cancel each other out, or the charge is balanced in charge.
  • the windings circulate between the windings and the secondary windings. Thus, as much as possible, the charge flow to the ground is avoided to generate common mode noise.
  • FIG. 9 is a schematic diagram showing the principle of suppressing common mode noise by the power conversion circuit of the embodiment of the present application.
  • the introduction of the charge balancing winding 63 can shield the common mode noise current generated by the transition voltage Vp on the one hand, and the common mode current and the secondary voltage generated by the potential of the charge balancing winding 63 on the other hand.
  • the charges generated by the potential of the winding 62 cancel each other out (i.e., internally circulate between the two), preventing the charge from flowing to the ground, thereby eliminating the common mode noise current.
  • the charge balancing winding 63 is disposed between the primary power winding and the secondary winding 62 of the planar transformer 60, and by designing the number of turns of the charge balancing winding 63, so that the planar transformer 60 operates.
  • the average voltage formed by the induced voltage of the charge balancing winding 63 is used to balance the average voltage formed by the induced voltage of the first secondary winding layer, thereby achieving a relationship between the charge balancing winding and the adjacent secondary winding.
  • the noise charges cancel each other out, thereby reducing noise in the power conversion circuit.
  • the first charge balancing winding layer includes an N 1 ⁇ coil.
  • N b1 N 1 turn coil for the induced voltage in the first secondary winding of the balancing layer.
  • N 1 is arranged such that the average value of the average value of the induced voltage of the first secondary winding and the induced voltage of layer N b1 N 1 of turns of the coil turns of the coils are equal.
  • N 1 and N b1 are positive numbers.
  • the number of turns of the coil involved in the embodiment of the present application may not be an integer ⁇ , for example, 1.5 ⁇ , 2.4 ⁇ .
  • N 1 and N b1 may or may not be equal. In the case where N 1 and N b are not equal, N 1 may be greater than N b1 .
  • N 1 and N b1 are not equal, when the planar transformer 60 is in operation, the configuration of N 1 may cause an induced current generated by the charge balancing winding to be used to cancel the voltage jump of the first end of the primary winding 61 Change the generated ground noise current.
  • the above ground noise current is a common mode noise current.
  • the first end of the primary winding 61 may be one end of the primary winding 61 connected to the primary switching transistor 511.
  • the voltage jump of the first end of the primary winding 61 described above may refer to a voltage jump generated by the trip voltage Vp.
  • the configuration of N 1 may cause the direction of the induced current generated by the charge balancing winding 63 to be opposite to the direction of the ground noise current generated by the primary winding 61, and the induced current
  • the size is equal to the magnitude of the ground noise current.
  • the configuration of the N 1 is such that the difference between the magnitude of the induced current and the magnitude of the ground noise is less than a first preset threshold, thereby improving power conversion.
  • the noise suppression performance of the circuit may be determined according to actual conditions.
  • the setting of N 1 is such that there is a potential difference between the first charge balance winding layer and the first secondary winding layer, the potential difference causes the first secondary winding layer to generate an induced current, and the first charge can be made by setting N 1
  • the induced current generated between the balanced winding and the first secondary winding layer is used to cancel the ground noise current generated by the voltage jump of the first end of the primary winding. Or it may be used to balance the noise current of the primary winding potential transition coupled to the secondary winding through the charge balance winding turn-to-turn gap.
  • the charge balancing winding includes a plurality of charge balancing winding layers
  • the number of turns of each of the plurality of charge balancing winding layers may be set such that the sensing generated in the plurality of charge balancing winding layers The sum of the charges can cancel the ground noise current generated by the voltage jump of the first end of the primary winding.
  • N 1 , N b1 satisfy the following conditions:
  • C 1 is a real number
  • the C 1 ⁇ coil is at least used to balance the noise current coupled to the secondary winding by the generated induced voltage.
  • the primary winding potential jump is coupled to the The noise current of the secondary winding.
  • the range of values of C 1 fluctuates within a certain range depending on the environmental parameters.
  • the value of C 1 can be [0, 1.1 * N b1 ].
  • C 1 value may be 0,0.1N b1, 0.2N b1, 0.3N b1 , 0.4N b1, 0.5N b1, 0.6N b1, 0.7N b1, 0.8N b1, 0.9N b1, 1.0N b1 , 1.05N b1 , 0.35N b1 , etc.
  • the noise current generated by the induced voltage generated by the C 1 ⁇ coil to the secondary winding may include an induced current generated between the first charge balancing winding layer and the first secondary winding layer as described above.
  • the noise current generated by the above-mentioned C 1 ⁇ coil coupled to the secondary winding can also be used to balance the noise current generated by other undesirable effects. For example, it can also be used to balance the ground noise current generated by the voltage jump of the first end of the primary winding described above.
  • N 1 and N 2 may be set such that the sum of the induced charges generated in the two charge balancing winding layers can A ground noise current generated by a voltage jump of the first end of the primary winding is cancelled.
  • N 2 , N b1 , and N b2 satisfy the following conditions:
  • C 2 is a real number
  • the C 2 ⁇ coil is used for at least a noise current balance coupled to the secondary winding by the generated induced voltage.
  • the primary winding potential jump is coupled to the The noise current of the secondary winding.
  • the range of values of C 2 fluctuates within a certain range depending on the environmental parameters. For example, the value range of C 2 may be [0, 1.1 * N b2 ].
  • C 2 values may be 0,0.1N b2, 0.2N b2, 0.3N b2 , 0.4N b2, 0.5N b2, 0.6N b2, 0.7N b2, 0.8N b2, 0.9N b2, 1.0N b2 , 1.05N b2 , 0.35N b2 , etc.
  • the noise current generated by the induced voltage generated by the C 2 turns coil to the secondary winding may include an induced current generated between the second charge balance winding layer and the second secondary winding layer.
  • the noise current generated by the above-mentioned C2 turns coil coupled to the secondary winding can also be used to balance the noise current generated by other undesirable effects. For example, it can also be used to balance the ground noise current generated by the voltage jump of the first end of the primary winding described above.
  • the charge balancing winding 63 is disposed between the primary power winding and the secondary winding 62 of the planar transformer, and by designing the number of turns of the charge balancing winding 63 so that when the planar transformer 60 is in operation
  • the induced voltage of at least a portion of the coils in the charge balancing winding 63 can be used to balance the induced voltage of the first secondary winding layer to suppress common mode noise generated by the secondary winding, thereby improving noise suppression performance.
  • the configuration of N 1 can also enable the induced current generated by the charge balancing winding to be used to cancel the ground noise current generated by the primary winding, thereby further improving the performance of noise suppression.
  • FIG. 10 is a schematic diagram of a noise path of a ground noise current in the power conversion circuit 50.
  • the first end of the primary winding 61 may be connected to the first end of the primary switching transistor 511 in the primary circuit, and the voltage transition of the first end of the primary winding 61 may refer to the primary switch.
  • the trip voltage Vp generated by the tube 511 when the high frequency is turned on or off.
  • the planar transformer 60 operates, the hopping voltage Vp generates a ground noise current Id through the above-described ground capacitance Cpe.
  • the value of C 1 or C 2 described above is related to the common mode current generated by the trip voltage of the first end of the primary winding 61 .
  • the charge balance winding 63 includes X charge balance winding layers, and the number of coil turns that need to be corrected for the above X charge balance winding layers are C 1 , C 2 , . . . , C X , respectively .
  • C 1 + C 2 +...+C X C', where X is an integer not less than 1.
  • the primary switching transistor in the primary circuit is provided with a heat sink. When the heat sink is connected to the primary potential static point, the noise current generated by the primary switching transistor to the heat sink is between the heat sink and the switching tube.
  • the primary switching transistor typically employs a surface mount process with no heat sink or heat sink connected to the primary potential dead point. Therefore, the first end of the primary switching transistor connected to the secondary winding (ie, the first end of the secondary winding) produces a ground noise current Id.
  • the value of C' such that the induced current of the C' ⁇ coil in the charge balancing winding is used to cancel the ground noise current generated by the voltage jump of the first end of the primary winding. Id.
  • a C' turns coil needs to be added to the charge balancing winding to counteract the ground noise current due to the voltage jump at the first end of the primary winding.
  • a C' turns coil can be added to the charge balance winding layer.
  • a modified C' ⁇ coil can be added to one or more of the charge balancing winding layers.
  • the C' turns coil may be added all to the second charge balance winding layer.
  • the C' turns coil can be divided into two parts, which are respectively added to the first charge balance winding layer and the second charge balance winding layer.
  • the increased C' ⁇ coil in the charge-balanced winding causes the charge-balanced winding to generate more induced current, and the magnitude of this portion of the induced current is the same as Id, and the direction is opposite to Id, ie, -Id.
  • the configuration of C' is such that the total charge generated by the secondary winding is equal to the magnitude of Qk , and the polarity is opposite. Thereby it can be used to cancel the noise current generated by the first end of the primary winding to the ground, or to cancel the noise current generated by the primary switching tube to the ground.
  • the number of turns of the charge balancing winding may be set assuming that the charge induced by the magnetic core to ground is Q c . equal, C 'configuration such that the secondary winding and the total charge Q c size, but opposite polarity.
  • the primary switching tube and the magnetic core of the power conversion circuit there is no primary potential static point. Assuming that the charge of the primary switching tube and the magnetic core of the magnetic core is Q d , then equal to the number of turns of the winding set charge balance, C 'configuration such that the secondary winding of the total charge Q d and size, but opposite polarity.
  • N 1 The configuration of N 1 will be described below by taking the first charge balancing winding layer as an example.
  • N 1 can satisfy the following conditions:
  • N 1 N b1 +C 1 ;
  • N b1 2 * N s1 + B 1 - 2.
  • C 1 is a constant, and the range of values of C 1 fluctuates within a certain range according to different environmental parameters.
  • C 1 may have a value range of [0.2*N b1 , 1.1*N b1 ].
  • the value of C 1 may be 0.3N b1 , 0.4N b1 , 0.5N b1 , 0.6N b1 , 0.7N b1 , 0.8N b1 , 0.9N b1 , 1.0N b1 , 1.05N b1 , 0.35N B1 and so on.
  • a secondary coil connecting the secondary potential of the secondary potential may be defined as a first winding of the secondary winding, assuming that the first secondary winding layer adjacent to the first charge balancing winding layer is provided with the secondary From the Nth s1 to N s1 +B 1 -1 ⁇ coils of the winding, according to the theoretical analysis of charge balance, the first charge-balanced winding layer and the adjacent first secondary winding layer are charge-balanced according to the following formula. :
  • V ta (N s1 -1)*V pt ; (4)
  • V ta+B (N s1 + B 1 -1) * V pt . (5)
  • V ta represents the induced voltage of the Nth s1 -1 ⁇ coil of the secondary winding
  • V ta+B1 represents the Nth s1 of the secondary winding +B 1 -1 ⁇ The induced voltage of the coil
  • V pt represents the induced voltage of a coil.
  • Formula (2) can be obtained by simultaneous derivation from equations (3)-(5).
  • N b1 2*N s1 +B 1 -2 (2)
  • N b1 2*N s1 -1 (6)
  • the process of determining C 1 will be continued below. It is assumed that the primary switching transistor 511 is a field effect transistor.
  • the maximum trip voltage Vb; in combination with the calculation and measurement, the common mode capacitance Csb between the charge balance winding 63 of the planar transformer 60 and the secondary mode 62 and the common mode capacitance Cbs between the secondary winding 62 and the charge balance winding 63 can be obtained.
  • Qpe represents the noise charge generated by Vp through Cpe
  • Qb1 represents the compensated noise charge generated by the charge balance winding correcting the number of turns C 1 , and Qb1 can be obtained according to formula (8):
  • N b1 represents a first number of turns before correction charge balancing winding layer
  • N s1 represents N s1 of the first secondary winding of the first layer and the layer adjacent to the charge balancing winding from the secondary winding The coil is wound
  • V pt represents the induced voltage of a coil.
  • FIG. 11 is a schematic cross-sectional view of a planar transformer 70 in accordance with another embodiment of the present application.
  • the planar transformer 70 includes a primary winding, a secondary winding, and a charge balancing winding, wherein the primary winding may be disposed on both sides of the secondary winding, and the charge balancing winding includes two charge balancing winding layers.
  • the primary winding layers included in the primary winding may be denoted by P1, P2, ..., Pn
  • the secondary winding layers included in the secondary winding may be denoted by S1, S2, ..., Sn
  • the above two charge balancing winding layers may be respectively used B1 and B2 are indicated.
  • the number of turns of the primary winding and the secondary winding in the planar transformer 70 can be set according to a preset turns ratio. For example, assume that the turns ratio of the primary winding to the secondary winding of the planar transformer 70 in FIG. 11 is 16:2. Therefore, the planar transformer 70 is provided with four primary winding layers (P1, P2, P3, P4), two secondary winding layers (S1, S2) and two charge balancing winding layers (B1, B2). Wherein, each primary winding layer is provided with 4 turns of coils, and each secondary winding layer is provided with 1 turn of coils.
  • the charge balance winding layer B1 is disposed between the primary winding layer P2 and the secondary winding layer S1, and the charge balance winding layer B2 is disposed between the primary winding layer P3 and the secondary winding layer S2. Therefore, the multilayer circuit board is viewed in the stacking direction in the order of P1, P2, B1, S1, S2, B2, P3, and P4.
  • the method of determining the number of turns of the charge balancing winding layer is described below, without considering the correction of the number of turns of the charge balancing winding. It is assumed that the secondary winding W1 is provided in the secondary winding layer S1, and the secondary winding Ws2 is provided in the secondary winding layer S2. It is assumed that one end of the secondary winding Ws1 is connected to the secondary potential dead point, and the other end of the secondary winding Ws1 is connected to Ws2.
  • the dielectric thickness between the inner conductors of the multilayer PCB board is 0.4 mm (mm) to meet the insulation requirements.
  • the dielectric thickness can be 0.4 mm or less to meet the insulation requirements.
  • the average potential of the coil Wb1 of the charge-balanced winding layer B1 opposite to S1 also needs to be 0.5V.
  • the coil Wb1 of the charge balance winding layer B1 is one turn.
  • Fig. 12 also shows a schematic diagram of the potential distribution of the coil Wb1 of the charge-balanced winding layer B1 circumferentially developed. As shown in Fig. 12, the potential distribution 207 of the coil Wb1 along the circumferential angle is 0-1 V, and the charge-balanced winding layer B1 The average potential 208 is 0.5V. It can be seen that the average potential of the coil Ws1 of the secondary winding layer S1 is equal to the average potential of the charge balance winding layer B1.
  • FIG. 13 shows a schematic diagram of the potential distribution of the coil Ws2 of the secondary winding layer S2 circumferentially spread.
  • the average potential of the coil Wb2 of the charge-balanced winding layer B2 opposite to S2 also needs to be 1.5V.
  • the coil Wb2 of the charge balance winding layer B2 is three turns.
  • FIG. 13 also shows a schematic diagram of the potential distribution of the three turns of the charge balance winding layer B2 circumferentially.
  • the potential distribution 215 of the first turn of the coil Wb2 along the circumferential angle is 0-1V.
  • the potential distribution 216 of the second turn of the coil Wb2 along the circumferential angle is 1-2V
  • the potential distribution 213 of the third turn of the coil Wb2 along the circumferential angle is 2-3V
  • FIG. 14 and 15 show schematic cross-sectional views of a planar transformer 80 in accordance with yet another embodiment of the present application.
  • the charge balance winding layer B1 in FIG. 14 is realized by an auxiliary power supply winding.
  • the charge balancing winding layer B2 of Figure 15 is implemented using an auxiliary power winding.
  • the primary winding in the planar transformer 80 further includes an auxiliary power supply winding including the auxiliary power supply winding layers A1, A2, assuming that a total of 6 are provided in A1 and A2. ⁇ In series of coils, assuming that the first winding of the auxiliary power winding is connected to the primary potential static point, the auxiliary power winding includes coils of the first ⁇ Na1, the second ⁇ Na2...the sixth ⁇ Na6.
  • the first winding coil Na1 of the auxiliary power winding can be used instead of the charge balancing winding layer B1 in the planar transformer 70 of FIG.
  • the 3-turn charge balancing winding in the balanced winding layer B2 in the planar plater 80 remains unchanged.
  • the second to sixth turns of the auxiliary winding in the planar transformer 80 may be disposed in the primary winding layer A2 of the primary winding.
  • the primary winding in the planar transformer 90 further includes an auxiliary power supply winding including the auxiliary power supply winding layers A1, A2, assuming that a total of 6 are provided in A1 and A2. ⁇ In series of coils, assuming that the first winding of the auxiliary power winding is connected to the primary potential static point, the auxiliary power winding includes coils of the first ⁇ Na1, the second ⁇ Na2...the sixth ⁇ Na6.
  • the first to third turns of the coils Na1, Na2, and Na3 of the auxiliary power supply winding can be used instead of the charge balance winding layer B2 of the planar transformer 70 of FIG.
  • the one turn coil in the balanced winding layer B1 in the plane leveler 90 remains unchanged.
  • the fourth to sixth turns of the auxiliary winding in the planar transformer 80 may be disposed in the primary winding layer A2 of the primary winding.
  • the auxiliary power supply winding can be used to form the charge balance winding, which can improve the noise suppression performance of the power conversion circuit, save the cost of the planar transformer, and improve the space utilization ratio of the planar transformer.
  • the charge balancing winding may be provided as a toroidal winding, and for the toroidal winding, although the charge balancing winding includes a charge-balanced winding layer having an average potential equal to that of the opposing secondary winding layer, the charge-balanced winding layer
  • the lengths of the turns of the inner and outer diameters are different. If the widths of the turns of the charge-balanced winding layers are the same, the areas of the turns of the turns are different, so that the capacitances of the turns of the secondary windings are different, resulting in the next secondary winding layer.
  • the net induced charge of the stage coil cannot be fully balanced to zero.
  • the embodiment of the present application proposes that the coil of the charge balance winding layer is successively reduced in width along the inner and outer diameters to make the charge balance winding layer and the adjacent secondary winding layer.
  • the capacitance is evenly distributed to reduce the net induced charge on the secondary winding layer when the planar voltage device is operating.
  • the N turns of the first charge balancing winding layer form a toroidal winding, and the width of the first to fourth coils of the toroidal winding is greater than the width of the (i+1)th coil. Wide, where N-1 ⁇ i ⁇ 1.
  • the coils of the charge balance winding layer are successively smaller along the inner and outer diameters of the inner and outer diameters, so that the capacitance between the charge balance winding layer and the adjacent secondary winding layer is evenly distributed, thereby improving noise suppression. performance.
  • FIG. 16 shows a schematic cross-sectional view of a planar transformer 100 in accordance with yet another embodiment of the present application.
  • the charge balance winding layer B2 includes a three-turn coil, and the width of the three-turn coil is gradually reduced as the average radius increases.
  • the widths of the turns of the turns on the first charge balancing winding layer may be set such that the areas of the turns of the turns are equal such that the distributed capacitance of the adjacent turns of the first secondary winding layer is the same .
  • the width of the ith coil of the first charge balancing winding layer may satisfy the following conditions:
  • R i is the average radius of the ith coil
  • R i+1 is the average radius of the ith +1 ⁇ coil
  • a i is the ⁇ width of the ith coil
  • a i+1 is The width of the ith i+1 turns coil.
  • the toroidal winding by setting the width of each of the coils of the charge balance winding layer along the inner and outer diameters so that the areas of the turns are equal, thereby making the charge balance winding layer and the adjacent secondary winding
  • the capacitance between the layers is evenly distributed, which can improve the performance of noise suppression.
  • the disclosed systems, devices, and methods may be implemented in other manners.
  • the device embodiments described above are merely illustrative.
  • the division of the unit is only a logical function division.
  • there may be another division manner for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored or not executed.
  • the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in an electrical, mechanical or other form.
  • the units described as separate components may or may not be physically separated, and the 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 of the embodiment.
  • each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, 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、电源转换电路以及适配器，能够提高噪声抑制的性能。该平面变压器包括：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，第一次级绕组层上设置有次级绕组的第Ns1匝至第Ns1+B1-1匝线圈；电荷平衡绕组，包括第一电荷平衡绕组层，第一电荷平衡绕组层设置于第一初级绕组层和第一次级绕组层之间，且与第一初级绕组层、第一次级绕组层相邻，第一电荷平衡绕组层上设置有N1匝线圈，其中，N1大于或等于Nb1，在平面变压器工作时，Nb1匝线圈产生的第一感应电压的平均值与第一次级绕组层产生的第二感应电压的平均值相等，N1、Nb1为正数。

Description

平面变压器、电源转换电路以及适配器
本申请要求于2017年11月10日提交中国专利局、申请号为201711105655.5、申请名称为“平面变压器、电源转换电路以及适配器”的中国专利申请的优先权，以及要求于2017年12月28日提交中国专利局、申请号为201711461419.7、申请名称为“平面变压器、电源转换电路以及适配器”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
本申请涉及电路领域，并且更具体地，涉及一种平面变压器、电源转换电路以及适配器。
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，如何降低甚至消除开关电源的噪声是业界非常关注的问题。
发明内容
本申请提供一种平面变压器、电源转换电路以及适配器，能够提高噪声抑制的性能。
第一方面，提供了一种平面变压器，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，所述第一次级绕组层上设置有所述次级绕组的第N s1匝至第N s1+B 1-1匝线圈，其中所述次级绕组的第1匝线圈用于连接电源转换电路的次级电路的电位静点，N s1、B 1为正数；电荷平衡绕组，包括第一电荷平衡绕组层，所述第一电荷平衡绕组层设置于所述第一初级绕组层和所述第一次级绕组层之间，且与所述第一初级绕组层、所述第一次级绕组层相邻，所述第一电荷平衡绕组层的第一端用于连接所述电源转换电路的初级电路的电位静点，所述第一电荷平衡绕组层上设置有N 1匝线圈，其中，N 1大于或等于N b1，在所述平面变压器工作时，N b1匝线圈产生的第一感应电压的平均值与所述第一次级绕组层产生的第二感应电压的平均值相等，N 1、N b1为正数。
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电荷平衡绕组，并且通过设计电荷平衡绕组包括的第一电荷平衡绕组层的线圈匝数，以使得在所述平面变压器工作时，所述第一电荷平衡绕组层中的至少部分线圈的感应电压能够用于平衡第 一次级绕组层的感应电压，以抑制次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，提供了一种平面变压器，其特征在于，N 1、N b1满足如下条件：N 1＝N b1+C 1，N b1＝2*N s1+B 1-2，其中，C 1为实数，C 1匝线圈至少用于通过产生的感应电压耦合到所述次级绕组的噪声电流平衡所述初级绕组电位跳变通过所述电荷平衡绕组匝间间隙耦合到所述次级绕组的噪声电流。
在一种可能的实现方式中，C 1的取值范围为[0,1.1*N b1]。
在一种可能的实现方式中，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，所述第二次级绕组层上设置有所述次级绕组的第N s2匝至第N s2+B 2-1匝线圈，其中，N s2、B 2为正数；所述电荷平衡绕组还包括第二电荷平衡绕组层，所述第二电荷平衡绕组层设置于所述第二初级绕组层和所述第二次级绕组层之间，且与所述第二初级绕组层、所述第二次级绕组层相邻，所述第二电荷平衡绕组层的第一端用于连接所述电源转换电路的初级电路的电位静点，所述第二电荷平衡绕组层上设置有N 2匝线圈，其中N 2大于或等于N b2，在所述平面变压器工作时，N b2匝线圈产生的第三感应电压的平均值与所述第二次级绕组层产生的第四感应电压的平均值相等，N 2、N b2为正数。
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电荷平衡绕组，电荷平衡绕组包括第一电荷平衡绕组层以及第二电荷平衡绕组层，且通过设计电荷平衡绕组的线圈匝数，以使得在所述平面变压器工作时，所述电荷平衡绕组中的至少部分线圈的感应电压能够用于平衡所述次级绕组的感应电压，以抑制次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，N 2、N b1、N b2满足如下条件：N 2＝N b2+C 2，N b1＝2*N s1+B 1-2，N b2＝2*N s2+B 2-2，N b2≥N b1，其中，C 2为实数，C 2匝线圈至少用于通过产生的感应电压耦合到所述次级绕组的噪声电流平衡所述初级绕组电位跳变通过所述电荷平衡绕组匝间间隙耦合到所述次级绕组的噪声电流。
在一种可能的实现方式中，C 2的取值范围为[0,1.1*N b2]。
在一种可能的实现方式中，所述初级绕组包括初级功率绕组，所述第一电荷平衡绕组层的所述第一端和所述初级功率绕组的第一端为同名端，其中，所述初级功率绕组的第一端用于连接所述初级电路的动点。
在本申请实施例中，通过设置第一电荷平衡绕组层的所述第一端和所述初级功率绕组的第一端为同名端，第一电荷平衡绕组层产生的感应电流方向与初级绕组产生的对地噪声电流的方向相反，进而能够抑制初级绕组产生的对地噪声电流，提高了电源转换电路的噪声抑制性能。
在一种可能的实现方式中，所述初级绕组包括辅助电源绕组，所述第一电荷平衡绕组层上设置的所述N 1匝线圈为所述辅助电源绕组的第1匝至第N 1匝线圈，其中所述辅助电源绕组的第1匝线圈用于连接所述初级电路的工作地。
在本申请实施例中，在平面变压器中设置电荷平衡绕组，可以利用辅助电源绕组作为电荷平衡绕组，以实现对电源转换电路中的噪声的抑制，并且减少了平面变压器的体积，节约了制造成本。
在一种可能的实现方式中，所述初级绕组设置于所述次级绕组的两侧，或，所述次级绕组设置于所述初级绕组的两侧。
在一种可能的实现方式中，在所述平面变压器工作时，在所述第一电荷平衡绕组层上设置的所述N 1匝线圈的第二端与任何导体之间不存在电性连接，且与任何元件之间也不存在电性连接。
在一种可能的实现方式中，B 1＝1。
在一种可能的实现方式中，所述第一电荷平衡绕组层中的N 1匝线圈形成环形绕组，且所述环形绕组中的第i匝线圈的匝宽大于第i+1匝线圈的匝宽，其中，所述第i匝线圈的平均半径小于所述第i+1匝线圈的平均半径，N 1-1≥i≥1。
在本申请实施例中，电荷平衡绕组层的线圈沿内外径各匝宽度逐次变小，以使得电荷平衡绕组层与相邻的次级绕组层之间的电容均匀分布，从而能够提高噪声抑制的性能。
在一种可能的实现方式中，所述第i匝线圈的匝宽满足如下条件：R i＝R i+1*a i+1/a i，
其中，R i为所述第i匝线圈的平均半径，R i+1为所述第i+1匝线圈的平均半径，a i为所述第i匝线圈的匝宽，a i+1为所述第i+1匝线圈的匝宽。
在本申请实施例中，针对环形绕组，通过设置电荷平衡绕组层的线圈沿内外径各匝的匝宽，以使得各匝线圈的面积相等，从而使得电荷平衡绕组层与相邻的次级绕组层之间的电容均匀分布，能够提高噪声抑制的性能。
第二方面，提供了一种电源转换电路，包括：如第一方面或第一方面中的任一种可能的实现方式中所述的平面变压器、初级电路以及次级电路，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，提供了一种适配器，包括如第二方面所述的电源转换电路。
附图说明
图1是本申请实施例的一种可能的应用场景的示意图。
图2是本申请实施例的电源转换电路的示意图。
图3是本申请又一实施例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是本申请又一实施例的电源转换电路的示意图。
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9是本申请实施例的电源转换电路抑制共模噪声的原理示意图。
图10是本申请实施例的电源转换电路对地噪声电流的噪声路径示意图。
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是本申请实施例的次级绕组层的线圈沿圆周展开的电位分布示意图。
图13是本申请又一实施例的次级绕组层的线圈沿圆周展开的电位分布示意图。
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是本申请另一实施例的平面变压器的截面示意图。
图16是本申请另一实施例的平面变压器的截面示意图。
具体实施方式
下面将结合附图，对本申请中的技术方案进行描述。
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。共模噪声可以通过在共模电感或者在两个输电线和地之间使用Y电容进行抑制。
差模噪声：差模噪声又称为正常型、对称噪声或线路间噪声，它存在于交流线路和中性导线中，二者相位差为180°。差模噪声的电流沿着一条交流线流出，并沿着另一条交流线返回，在地线中不存在差模噪声电流。
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。
初级电路的动点：可以指在电路拓扑的初级侧随着初级开关管的开通与关断有着电压跳变的电路节点或者网络，如初级功率绕组与开关管连接的节点。
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，两个相邻的绕组层即两个所在平面平行，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在能够降低工作时产生的噪声。上述噪声可以包 括共模噪声。进一步地，上述噪声可以包括差模噪声。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。在相关技术中，开关电源的噪声分为差模噪声和共模噪声，差模噪声主要由开关变换器的脉动电流引起，可以采用滤波器进行抑制。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。其中，在本申请实施例中，初级电路的电位静点也可以称为初级电位静点，次级电路的电位静点也可以称为次级电位静点。
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和次级整流管221由于高频的导通与关断，分别产生跳变电压Vp和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，可以认为流入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，可以采用屏蔽体屏蔽的方法，上述屏蔽体31与初级电位静点连接，并包裹初级绕组231，以屏蔽掉初级的跳变电压Vp对次级绕组232的共模噪声同时，可以在电源转换电路20的初级电路和次级电路之间设置Y电容。Y电容的两端可以分别与初级电位静点以及次级电位 静点相连。换句话说，上述连接方式等效于Y电容并联于LISN的两侧，让原本通过LISN的共模噪声通过Y电容支路分流，从而降低LISN检测出的噪声电流。
但是，上述屏蔽体31并不能从源头上消除噪声源Vp和Vs，增加的Y电容不仅会使得成本上升和体积增加，更会带来初级电路21和次级电路22之间的工频漏电流，带来漏电安全隐患。
针对上述问题，本申请实施例提出了一种平面变压器、电源转换电路以及适配器，能够为提高电源转换电路的噪声抑制性能提供一种解决方案。进一步地，由于能够充分地抑制共模噪声，本申请实施例中的电源转换电路可以取消跨接在初级电路和次级电路上的Y电容，从而能够提供无Y电容的安全性更高的电源转换电路。
下面将结合附图，详细介绍本申请实施例的电源转换电路50。上述电源转换电路50可以应用于适配器。上述电源转换电路50包括初级电路51、次级电路52和平面变压器53。
图5是本申请实施例的电源转换电路50的示意图。如图5所示，上述电源转换电路50包括初级电路51、次级电路52、平面变压器60。其中，初级电路51的结构与图2中的初级电路21相同或相似。次级电路52与图2中的次级电路22相同或相似，此处不再赘述。接下来介绍平面变压器60。
图6示出了本申请实施例的平面变压器60的结构示意图，如图6所示，上述平面变压器60包括初级绕组61、次级绕组62以及电荷平衡绕组63。平面变压器60还可以包括磁芯64。本申请实施例对磁芯64的材质不作限定。例如，上述磁芯64可以是EE型、EI型或者RM型。上述磁芯64的绕线柱上可以设置有多层电路板构成的所述初级绕组61、所述次级绕组62以及所述电荷平衡绕组63。
图7是本申请实施例的平面变压器60的截面示意图。如图7所示，上述初级绕组61可以包括至少一个初级绕组层。初级绕组61包括的各初级绕组层可以用P1、P2、…、Pn表示。其中，图7中使用P表示各初级绕组层。需要说明的是，由于平面变压器60的截面是对称的，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11、图14-图15展示了平面变压器的半截面图示意图。
初级绕组61可以包括初级功率绕组，进一步地，上述初级绕组61还可以包括辅助电源绕组。
其中，辅助电源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。
上述至少一个初级绕组层可以设置有初级功率绕组的线圈，或者，还可以设置辅助电源绕组的线圈。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。上述初级绕组61可以包括第一初级绕组层。第一初级绕组层上可以设置初级功率绕组的至少部分线圈，或者，也可以设置辅助电源绕组的至少部分线圈。
上述次级绕组62可以包括至少一个次级绕组层。次级绕组62包括的各次级绕组层可以用S1、S2、…、Sn表示。与初级绕组61相似，上述至少一个次级绕组层上设置的线圈相互串联。上述次级绕组62可以包括第一次级绕组层。
上述电荷平衡绕组63可以包括至少一个电荷平衡绕组层。上述至少一个电荷平衡绕 组层可以用B1、B2等表示。下面以至少一个电荷平衡绕组层包括第一电荷平衡绕组层为例，对电荷平衡绕组层进行描述。第一电荷平衡绕组层可以是上述至少一个电荷平衡绕组层中的任意一个电荷平衡绕组层。第一电荷平衡绕组层可以设置于第一初级绕组层和第一次级绕组层之间，且与第一初级绕组层以及第一次级绕组层相邻。所述第一次级绕组层上设置有所述次级绕组的第N s1匝至第N s1+B 1-1匝线圈，其中所述次级绕组的第1匝线圈用于连接电源转换电路的次级电路的电位静点，N s1、B 1为正数。其中，N 1大于或等于N b1，在所述平面变压器工作时，N b1匝线圈产生的第一感应电压的平均值与所述第一次级绕组层产生的第二感应电压的平均值相等，N 1、N b1为正数。
其中，上述第一电荷平衡绕组层与第一初级绕组层以及第一次级绕组层相邻，是指第一电荷平衡绕组层与第一初级绕组层之间不存在其他绕组层，以及第一电荷平衡绕组层与第一次级绕组层之间也不存在其他绕组层。
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电荷平衡绕组，并且通过设计电荷平衡绕组包括的第一电荷平衡绕组层的线圈匝数，以使得在所述平面变压器工作时，所述第一电荷平衡绕组层中的至少部分线圈的感应电压能够用于平衡第一次级绕组层的感应电压，以抑制次级绕组产生的共模噪声，从而提高噪声抑制的性能。
进一步地，由于能够充分地抑制共模噪声，本申请实施例中的电源转换电路可以取消跨接在初级电路和次级电路上的Y电容，从而能够提供无Y电容的安全性更高的电源转换电路。
进一步地，上述至少一个电荷平衡绕组还可以包括第二电荷平衡绕组层，第二电荷平衡绕组层与第一电荷平衡绕组层的设置相似。例如，上述所述初级绕组61还包括第二初级绕组层；所述次级绕组62还包括第二次级绕组层，所述第二次级绕组层上设置有所述次级绕组的第N s2匝至第N s2+B 2-1匝线圈，其中，N s2、B 2为正数；所述电荷平衡绕组63还包括第二电荷平衡绕组层，所述第二电荷平衡绕组层设置于所述第二初级绕组层和所述第二次级绕组层之间，且与所述第二初级绕组层、所述第二次级绕组层相邻，所述第二电荷平衡绕组层的第一端用于连接所述电源转换电路的初级电路的电位静点，所述第二电荷平衡绕组层上设置有N 2匝线圈，其中N 2大于或等于N b2，在所述平面变压器工作时，N b2匝线圈产生的第三感应电压的平均值与所述第二次级绕组层产生的第四感应电压的平均值相等，N 2、N b2为正数。
其中，上述第二电荷平衡绕组层与第二初级绕组层以及第二次级绕组层相邻，是指第二电荷平衡绕组层与第二初级绕组层之间不存在其他绕组层，以及第二电荷平衡绕组层与第二次级绕组层之间也不存在其他绕组层。
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电荷平衡绕组，电荷平衡绕组包括第一电荷平衡绕组层以及第二电荷平衡绕组层，且通过设计电荷平衡绕组的线圈匝数，以使得在所述平面变压器工作时，所述电荷平衡绕组中的至少部分线圈的感应电压能够用于平衡所述次级绕组的感应电压，以抑制次级绕组产生的共模噪声，从而提高噪声抑制的性能。
进一步地，N 1的配置还能够使得所述电荷平衡绕组产生的感应电流能够用于抵消所述初级绕组产生的对地噪声电流，从而进一步提高噪声抑制的性能。关于N 1或N 2的配置方式，后文中将结合图9和图10进行详细描述。
在一个示例中，所述初级绕组61包括初级功率绕组，所述第一电荷平衡绕组层的所述第一端和所述初级功率绕组的第一端为同名端，其中，所述初级功率绕组的第一端用于连接所述初级电路的动点。在这种情况下，第一电荷平衡绕组层产生的感应电流方向与初级绕组产生的对地噪声电流的方向相反，进而能够抑制初级绕组产生的对地噪声电流。
其中，上述初级电路的动点可以指在电路拓扑的初级侧随着初级开关管的开通与关断有着电压跳变的电路节点或者网络，如初级功率绕组与初级开关管连接的节点
在本申请实施例中，通过设置第一电荷平衡绕组层的所述第一端和所述初级功率绕组的第一端为同名端，第一电荷平衡绕组层产生的感应电流方向与初级绕组产生的对地噪声电流的方向相反，进而能够抑制初级绕组产生的对地噪声电流，提高了电源转换电路的噪声抑制性能。
图8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8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212和次级滤波电容222可以采用电解电容。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位静点，或者，初级电路的地节点也可以为初级电位静点。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位静点。
如图8所示，初级绕组61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62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61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62的两端分别与次级整流管521以及次级滤波电容522相连。上述电荷平衡绕组63的一端用于与电源转换电路50的初级电位静点相连，上述电荷平衡绕组的另一端可以悬空。其中，上述悬空可以指电荷平衡绕组的另一端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，电荷平衡绕组63的一端可以与初级滤波电容512相连。以上述电荷平衡绕组63包括第一电荷平衡绕组层为例，则上述第一电荷平衡绕组层的N 1匝线圈的第一端用于与所述初级电位静点相连，上述第一电荷平衡绕组的N 1匝线圈的第二端可以悬空，即与任何导体或元件之间都不存在电性连接。
在一些示例中，在所述初级绕组还包括辅助电源绕组的情况下，可以利用辅助电源绕组替代第一电荷平衡绕组。具体地，辅助电源绕组的一端与初级电位静点相连，假设所述辅助电源绕组中的第1匝线圈与初级电位静点相连。其中，则所述第一电荷平衡绕组层上设置的所述N 1匝线圈可以为所述辅助电源绕组的第1匝至第N 1匝线圈。
在上述示例中，若所述辅助电源绕组包括P匝线圈，P大于N 1，则辅助电源绕组中的第N 1+1匝至第P匝线圈可以设置于初级绕组包括的至少一个初级绕组层中。
在本申请实施例中，在平面变压器中设置电荷平衡绕组，可以利用辅助电源绕组作为电荷平衡绕组，以实现对电源转换电路中的噪声的抑制，并且减少了平面变压器的体积，节约了制造成本。
需要说明的是，上述第一电荷平衡绕组层的一端需要连接初级电位静点，上述第一电荷平衡绕组层的另一端可以悬空，也可以连接其他电位节点。例如，当上述第一电荷平衡绕组层的线圈为辅助电源绕组中的至少部分线圈时，所述第一电荷平衡绕组层的一 端与初级电位静点相连，所述第一电荷平衡绕组层的另一端可以不悬空，而是与辅助电源绕组中的第N 1+1匝线圈相连。
可选地，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形式。例如，在第一种形式中，参见图7所示，可以将初级绕组设置在次级绕组的两侧，即，将初级绕组中的一部分初级绕组层设置在次级绕组的一侧，将初级绕组的另一部分初级绕组层设置在次级绕组的另一侧，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，在第二种形式中，也可以将次级绕组设置在初级绕组的两侧。或者，在第三种形式中，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。
在上述第一种形式或第二种形式中，初级绕组和次级绕组存在两处相邻的位置，因此，上述电荷平衡绕组可以包括两个电荷平衡绕组层，并分别设置于相邻的初级绕组层和次级绕组层之间。在上述第三种形式中，上述电荷平衡绕组可以包括一个电荷平衡绕组层。
具体地，针对消除共模噪声，一方面，由于上述电荷平衡绕组63的一端与初级电位静点相连，因此能够屏蔽初级绕组61的跳变电压Vp产生的共模噪声电流。另一方面，可以通过设置电荷平衡绕组63的线圈匝数，使得电荷平衡绕组63的电位产生的共模电流与次级绕组62的电位产生的噪声电荷相互抵消，或者说，使得电荷在电荷平衡绕组与次级绕组之间相互循环。从而尽可能的避免电荷流向地而产生共模噪声。
图9是本申请实施例的电源转换电路抑制共模噪声的原理示意图。如图9所示，从噪声路径电路图上看，电荷平衡绕组63的引入一方面可以屏蔽跳变电压Vp产生的共模噪声电流，一方面由于电荷平衡绕组63电位产生的共模电流与次级绕组62电位产生的电荷相互抵消(即在两者之间内部循环)，避免电荷流向大地，从而消除了共模噪声电流。
在本申请实施例中，通过在平面变压器60的初级功率绕组和次级绕组62之间设置电荷平衡绕组63，且通过设计电荷平衡绕组63的线圈匝数，以使得在所述平面变压器60工作时，所述电荷平衡绕组63的感应电压形成的平均电压用于平衡所述第一次级绕组层的感应电压形成的平均电压，由此可以实现电荷平衡绕组与相邻次级绕组之间的噪声电荷相互抵消，从而降低了电源转换电路中的噪声。
具体地，以第一电荷平衡绕组层为例，第一电荷平衡绕组层包括N 1匝线圈。在所述平面变压器工作时，所述N 1匝线圈中的N b1匝线圈的感应电压用于平衡所述第一次级绕组层的感应电压。或者说，N 1的配置使得N 1匝线圈中的N b1匝线圈的感应电压的平均值与所述第一次级绕组层的感应电压的平均值相等。其中N 1、N b1为正数。
需要说明的是，在实际应用中，由于绕组的特性和原理，本申请实施例涉及的线圈匝数可以不是整数匝，例如，可以是1.5匝、2.4匝。
N 1与N b1可以相等，也可以不相等。在N 1与N b不相等的情况下，N 1可以大于N b1。
当N 1与N b1不相等时，在所述平面变压器60工作时，N 1的配置可以使所述电荷平衡绕组产生的感应电流可以用于抵消所述初级绕组61的第一端的电压跳变产生的对地噪声电流。上述对地噪声电流为共模噪声电流。
其中，上述初级绕组61的第一端可以是初级绕组61与初级开关管511相连的一端。 例如，上述初级绕组61的第一端的电压跳变可以指跳变电压Vp产生的电压跳变。
需要说明的是，在理想情况下，N 1的配置可以使所述电荷平衡绕组63产生的感应电流的方向与所述初级绕组61产生的对地噪声电流的方向相反，且所述感应电流的大小与所述对地噪声电流的大小相等。但是实际情况中，由于各种寄生参数较为复杂，所述N 1的的配置使得所述感应电流的大小与所述对地噪声的大小的差值小于第一预设阈值，从而提高了电源转换电路的噪声抑制的性能。所述第一预设阈值的取值可以根据实际情况确定。
具体地，所述N 1的设置使得第一电荷平衡绕组层与第一次级绕组层之间存在电势差，该电势差使得第一次级绕组层产生感应电流，通过设置N 1可以使得第一电荷平衡绕组与第一次级绕组层之间产生的感应电流用于抵消所述初级绕组的第一端的电压跳变产生的对地噪声电流。或者还可以用于平衡所述初级绕组电位跳变通过所述电荷平衡绕组匝间间隙耦合到所述次级绕组的噪声电流。还需说明的是，当电荷平衡绕组包括多个电荷平衡绕组层时，可以设置多个电荷平衡绕组层中的每个电荷平衡绕组层的匝数，使得多个电荷平衡绕组层中产生的感应电荷总和能够抵消所述初级绕组的第一端的电压跳变产生的对地噪声电流。
例如，若电荷平衡绕组63包括第一电荷平衡绕组层，则N 1、N b1满足如下条件：
N 1＝N b1+C 1，N b1＝2*N s1+B 1-2，
其中，C 1为实数，C 1匝线圈至少用于通过产生的感应电压耦合到所述次级绕组的噪声电流平衡所述初级绕组电位跳变通过所述电荷平衡绕组匝间间隙耦合到所述次级绕组的噪声电流。C 1的取值范围根据环境参数的不同而在一定范围内波动。例如，C 1的取值范围可以为[0,1.1*N b1]。在一些示例中，C 1的取值可以为0、0.1N b1、0.2N b1、0.3N b1、0.4N b1、0.5N b1、0.6N b1、0.7N b1、0.8N b1、0.9N b1、1.0N b1、1.05N b1、0.35N b1等。
其中，上述C 1匝线圈产生的感应电压耦合到所述次级绕组的噪声电流可以包括前文所述的第一电荷平衡绕组层与第一次级绕组层之间产生的感应电流。另外，上述C 1匝线圈产生的感应电压耦合到所述次级绕组的噪声电流也可以用于平衡其他不理想效应产生的噪声电流。例如，还可以用于平衡前文所述的初级绕组的第一端的电压跳变产生的对地噪声电流。
例如，当电荷平衡绕组63包括第一电荷平衡绕组层和第二电荷平衡绕组层的情况下，可以对N 1和N 2进行设置，以使得两个电荷平衡绕组层中产生的感应电荷总和能够抵消所述初级绕组的第一端的电压跳变产生的对地噪声电流。
N 2、N b1、N b2满足如下条件：
N 2＝N b2+C 2，N b1＝2*N s1+B 1-2，N b2＝2*N s2+B 2-2，N b2≥N b1，
其中，C 2为实数，C 2匝线圈至少用于通过产生的感应电压耦合到所述次级绕组的噪声电流平衡所述初级绕组电位跳变通过所述电荷平衡绕组匝间间隙耦合到所述次级绕组的噪声电流。C 2的取值范围根据环境参数的不同而在一定范围内波动。例如，C 2的取值范围可以为[0,1.1*N b2]。在一些示例中，C 2的取值可以为0、0.1N b2、0.2N b2、0.3N b2、0.4N b2、0.5N b2、0.6N b2、0.7N b2、0.8N b2、0.9N b2、1.0N b2、1.05N b2、0.35N b2等。
其中，上述C 2匝线圈产生的感应电压耦合到所述次级绕组的噪声电流可以包括第二电荷平衡绕组层与第二次级绕组层之间产生的感应电流。另外，上述C2匝线圈产生的感 应电压耦合到所述次级绕组的噪声电流也可以用于平衡其他不理想效应产生的噪声电流。例如，还可以用于平衡前文所述的初级绕组的第一端的电压跳变产生的对地噪声电流。
在本申请实施例中，通过在平面变压器的初级功率绕组和次级绕组62之间设置电荷平衡绕组63，且通过设计电荷平衡绕组63的线圈匝数，以使得在所述平面变压器60工作时，所述电荷平衡绕组63中的至少部分线圈的感应电压能够用于平衡所述第一次级绕组层的感应电压，以抑制次级绕组产生的共模噪声，从而提高噪声抑制的性能。进一步地，N 1的配置还能够使得所述电荷平衡绕组产生的感应电流能够用于抵消所述初级绕组产生的对地噪声电流，从而进一步提高噪声抑制的性能。
为了便于理解上述方案，图10是电源转换电路50中对地噪声电流的噪声路径示意图。如图10所示，所述初级绕组61的第一端可以与初级电路中的初级开关管511的第一端相连，所述初级绕组61的第一端的电压跳变可以指所述初级开关管511在高频导通或关断时产生的跳变电压Vp。初级开关管511与地之间存在对地电容Cpe。在平面变压器60工作的情况下，跳变电压Vp会通过上述对地电容Cpe产生对地噪声电流Id。
可选地，上述C 1或C 2的取值与初级绕组61的第一端的跳变电压产生的对地共模电流相关。假设电荷平衡绕组63包括X个电荷平衡绕组层，上述X个电荷平衡绕组层需要修正的线圈匝数分别为C 1、C 2、…、C X。假设C 1+C 2+…+C X＝C’，其中，X是不小于1的整数。在一些实施例中，初级电路中的初级开关管设置有散热器，在上述散热器与初级电位静点相连的情况下，初级开关管对散热器产生的噪声电流在散热器和开关管之间循环，而不会流向地。在这种情况下，初级绕组的第一端不存在对地噪声电流，因此可以设置C’＝0。在另一些实施例中，随着功率密度和高频化的发展，初级开关管通常采用表面贴装工艺，没有散热器或者散热器没有连接初级电位静点。因此初级开关管与次级绕组相连的第一端(即次级绕组的第一端)会产生对地噪声电流Id。在这种情况下，需要设置C’的取值，以使得电荷平衡绕组中的C’匝线圈的感应电流用于抵消由于所述初级绕组的第一端的电压跳变产生的对地噪声电流Id。例如，在图10的电路中，则需要在电荷平衡绕组中增加C’匝线圈，以抵消由于所述初级绕组的第一端的电压跳变产生的对地噪声电流。
在这种情况下，若电荷平衡绕组包括一个电荷平衡绕组层，可以将C’匝线圈增加到该电荷平衡绕组层中。若电荷平衡绕组层包括多个电荷平衡绕组层，可以将修正的C’匝线圈加到其中一个或多个电荷平衡绕组层中。例如，若电荷平衡绕组层包括第一电荷平衡绕组层和第二电荷平衡绕组层，可以将C’匝线圈加入全部加入至第二电荷平衡绕组层。或者也可以将C’匝线圈分成两部分，分别加入第一电荷平衡绕组层和第二电荷平衡绕组层中。例如，在电荷平衡绕组中增加的C’匝线圈使得电荷平衡绕组产生更多的感应电流，并且使这部分感应电流的大小与Id相同，方向与Id相反，即-Id。或者可以理解为，假设初级开关管的对地电容感应的电荷为Q k，C’的配置使得次级绕组产生的总电荷与Q k大小相等，而极性相反。从而能够用于抵消初级绕组的第一端对地产生的噪声电流，或者说，用于抵消初级开关管对地产生的噪声电流。
可选地，在一些示例中，对于平面变压器的磁芯没有连接初级电位静点的情况，假设磁芯对地电容感应的电荷为Q c，则可以对所述电荷平衡绕组的匝数进行设置，C’的配 置使得次级绕组产生的总电荷与Q c大小相等，而极性相反。
可选地，在一些示例中，对于电源转换电路的初级开关管和磁芯都没有接初级电位静点的情况，假设初级开关管和磁芯的对地电容感应的电荷为Q d，则可以对所述电荷平衡绕组的匝数进行设置，C’的配置使得次级绕组产生的总电荷与Q d大小相等，而极性相反。
下文以第一电荷平衡绕组层为例，对N 1的配置进行描述。
可选地，N 1可以满足如下条件：
N 1＝N b1+C 1；                   (1)
N b1＝2*N s1+B 1-2。                 (2)
其中，N、N b为正数，C 1为常数，C 1的取值范围根据环境参数的不同而在一定范围内波动。例如，C 1的取值范围可以为[0.2*N b1,1.1*N b1]。在一些示例中，C 1的取值可以为0.3N b1、0.4N b1、0.5N b1、0.6N b1、0.7N b1、0.8N b1、0.9N b1、1.0N b1、1.05N b1、0.35N b1等。
下面介绍公式(2)的推导过程。假设次级绕组包括m匝线圈，m为正数。可以将连接次级电位静点的次级线圈定义为次级绕组的第一匝线圈，假设与所述第一电荷平衡绕组层相邻的所述第一次级绕组层设置有所述次级绕组的第N s1至第N s1+B 1-1匝线圈，则根据电荷平衡的理论分析可知，符合以下公式时，第一电荷平衡绕组层与相邻的第一次级绕组层达到电荷平衡：
[V ta+V ta+B1]/2＝N b1*V pt/2；                (3)
V ta＝(N s1-1)*V pt；                 (4)
V ta+B＝(N s1+B 1-1)*V pt。                (5)
其中，N b1表示第一电荷平衡绕组层的线圈匝数，V ta表示所述次级绕组的第N s1-1匝线圈的感应电压；V ta+B1表示所述次级绕组的第N s1+B 1-1匝线圈的感应电压。V pt表示一匝线圈的感应电压。
由公式(3)-(5)联立推导可得到公式(2)。
N b1＝2*N s1+B 1-2                 (2)
可选地，在一些实施例中，第一次级绕组层中设置的线圈匝数为1，即B 1＝1，则上述公式(2)可以简化为如下公式:
N b1＝2*N s1-1                  (6)
作为一个具体示例，下面继续介绍确定C 1的过程。假设初级开关管511为场效应晶体管。可以测量初级开关管511的源(S)极对地寄生电容Cpe，初级开关管511漏(D)极的跳变电压Vp，次级电路电位静点对地寄生电容Cse，电荷平衡绕组上的最大跳变电压Vb；结合计算与测量可以获取平面变压器60的电荷平衡绕组63对次级绕组62之间的共模电容Csb和次级绕组62对电荷平衡绕组63之间的共模电容Cbs。
假设Qpe表示由Vp通过Cpe产生的噪声电荷，Qpe可以根据公式(7)获得。
Qpe＝Vp*Cpe                 (7)
假设Qb1表示由电荷平衡绕组修正匝数C 1后产生的补偿噪声电荷，Qb1可以根据公式(8)获得：
Figure PCTCN2018114303-appb-000001
当Qpe＝Qb1时，整个系统中噪声电荷达到平衡，因此综合公式(7)和(8)，得到公式(9)：
Figure PCTCN2018114303-appb-000002
其中，N b1表示第一电荷平衡绕组层的修正前的线圈匝数，N s1表示与所述第一电荷平衡绕组层相邻的第一次级绕组层从所述次级绕组的第N s1匝线圈起绕，V pt表示一匝线圈的感应电压。
需要说明的是，由于在高频电磁干扰(electromagnetic interference,EMI)模型中，实际的工程应用中各种杂散寄生参数非常复杂，因为根据以上计算出的C 1在实际应用可以允许一定范围内的上下波动。
图11是本申请另一实施例的平面变压器70的截面示意图。如图11所示，平面变压器70包括初级绕组、次级绕组和电荷平衡绕组，其中，初级绕组可以设置于次级绕组的两侧，电荷平衡绕组包括两个电荷平衡绕组层。初级绕组包括的各初级绕组层可以用P1、P2、…、Pn表示，次级绕组包括的各次级绕组层可以用S1、S2、…、Sn表示，上述两个电荷平衡绕组层可以分别用B1和B2表示。
平面变压器70中的初级绕组和次级绕组的匝数可以根据预设的匝比进行设置。例如，假设图11中的平面变压器70的初级绕组与次级绕组的匝比为16:2。因此，平面变压器70设置有4个初级绕组层(P1、P2、P3、P4)、两个次级绕组层(S1、S2)以及两个电荷平衡绕组层(B1、B2)。其中，每个初级绕组层设置4匝线圈，每个次级绕组层设置1匝线圈。电荷平衡绕组层B1设置于初级绕组层P2和次级绕组层S1之间，电荷平衡绕组层B2设置于初级绕组层P3和次级绕组层S2之间。因此，多层电路板沿堆叠方向来看，顺序依次为P1、P2、B1、S1、S2、B2、P3、P4。
继续参见图11，在不考虑电荷平衡绕组的线圈匝数修正的情况下，下面介绍确定电荷平衡绕组层的线圈匝数的方法。假设次级绕组层S1中设置有次级线圈Ws1，次级绕组层S2中设置有次级线圈Ws2。假设次级线圈Ws1的一端连接次级电位静点，次级线圈Ws1的另一端连接Ws2。针对电荷平衡绕组层B1，与之相邻的次级绕组层S1设置有次级绕组的第一匝线圈，因此Ns＝1，B＝1，假设c＝0，将上述赋值代入公式(1)和公式(2)，得到N＝Nb＝1。因此，电荷平衡绕组层B1中设置有1匝线圈Wb1。针对电荷平衡绕组层B2，与之相邻的次级绕组层S2设置有次级绕组的第2匝线圈，因此Ns＝2，B＝1，假设c＝0，将上述赋值代入公式(1)和公式(2)，得到N＝Nb＝3因此，电荷平衡绕组层B1中设置有三匝线圈Wb2。其中，线圈Wb1和线圈Wb2的一端分别连接初级电位静点，线圈Wb1和线圈Wb2的另一端悬空，即不作任何电连接。
在一些具体实施例中，为了满足使用安全性，电源转换电路的初级电路和次级电路之间需要满足绝缘性能。由于电荷平衡绕组层B1和B2连接初级电位静点，因此，电荷平衡绕组属于电源转换电路的初级电路。因此，电荷平衡绕组层B1和次级绕组层S1之 间，以及电荷平衡绕组层B2和次级绕组层S2之间需要留有足够的距离，以满足绝缘要求。例如，在具体实现中，多层PCB板内层导体之间的介质厚度达到0.4毫米(mm)可以满足绝缘要求。或者，对于内层导电体之间的介质能够实现附加绝缘的情况，介质厚度做到0.4mm以下也可以满足绝缘要求。
下面根据图11的平面变压器70的具体示例，介绍平面变压器的抑制噪声的原理。由变压器的原理可知，变压器中每一匝线圈所感应的电压都相等。因此，下文中假设每一匝线圈的感应电压为1V。图12示出了将次级绕组层S1的线圈Ws1沿圆周展开的电位分布示意图。如图12所示，线圈Ws1沿周向角度的电位分布205为0-1V，平均电位206为(0V+1V)/2＝0.5V。为了保证次级绕组层S1中的线圈Ws1的感应电荷为零，与S1相对的电荷平衡绕组层B1的线圈Wb1的平均电位也需要为0.5V。电荷平衡绕组层B1的线圈Wb1为一匝。图12还示出了将电荷平衡绕组层B1的线圈Wb1沿圆周展开的电位分布示意图，如图12所示，线圈Wb1沿周向角度的电位分布207为0-1V，则电荷平衡绕组层B1的平均电位208为0.5V。可见，次级绕组层S1的线圈Ws1的平均电位与电荷平衡绕组层B1的平均电位相等。
同理，图13示出了将次级绕组层S2的线圈Ws2沿圆周展开的电位分布示意图。如图13所示，线圈Ws2沿周向角度的电位分布209为1-2V，平均电位210为(1V+2V)/2＝1.5V。为了保证次级绕组层S2中的线圈Ws2的感应电荷为零，与S2相对的电荷平衡绕组层B2的线圈Wb2的平均电位也需要为1.5V。电荷平衡绕组层B2的线圈Wb2为三匝。图13还示出了将电荷平衡绕组层B2的三匝线圈Wb2沿圆周展开的电位分布示意图，如图13所示，线圈Wb2的第一匝沿周向角度的电位分布215为0-1V，线圈Wb2的第二匝沿周向角度的电位分布216为1-2V，线圈Wb2的第三匝沿周向角度的电位分布213为2-3V，则电荷平衡绕组层B2的平均电位214为(0V+3V)/2＝1.5V。可见，次级绕组层S2的线圈Ws2的平均电位与电荷平衡绕组层B2的平均电位相等。
通过以上分析可以知，电荷平衡绕组层B1中的线圈Wb1与次级绕组层S1中的线圈Ws1的平均电位相同，则Ws1没有净感应电荷；同样，电荷平衡绕组层B2中的线圈Wb2与次级绕组层S2的线圈Ws2的平均电位相同，则Ws2没有净感应电荷。因此，使得整个次级绕组没有净感应电荷，从而消除了通过次级绕组产生的共模噪声。
图14和图15示出了本申请又一实施例的平面变压器80的截面示意图。其中，图14中的电荷平衡绕组层B1利用辅助电源绕组实现。图15中的电荷平衡绕组层B2利用辅助电源绕组实现。
参见图14，在图11的平面变压器70的基础上，平面变压器80中的初级绕组还包括辅助电源绕组，该辅助电源绕组包括辅助电源绕组层A1、A2，假设在A1和A2中共设置有6匝串联的线圈，假定辅助电源绕组的第一匝线圈与初级电位静点相连，辅助电源绕组包括的线圈依次为第1匝Na1、第2匝Na2…第6匝Na6。
如图14所示，可以采用辅助电源绕组的第1匝线圈Na1替代图11中的平面变压器70中的电荷平衡绕组层B1。平面平压器80中的平衡绕组层B2中的3匝电荷平衡绕组保持不变。平面变压器80中的辅助绕组的第2匝至第6匝线圈可以设置于初级绕组的初级绕组层A2中。
参见图15，在图11的平面变压器70的基础上，平面变压器90中的初级绕组还包括 辅助电源绕组，该辅助电源绕组包括辅助电源绕组层A1、A2，假设在A1和A2中共设置有6匝串联的线圈，假定辅助电源绕组的第一匝线圈与初级电位静点相连，辅助电源绕组包括的线圈依次为第1匝Na1、第2匝Na2…第6匝Na6。
如图15所示，可以采用辅助电源绕组的第1匝至第3匝线圈Na1、Na2、Na3替代图11中的平面变压器70中的电荷平衡绕组层B2。平面平压器90中的平衡绕组层B1中的1匝线圈保持不变。平面变压器80中的辅助绕组的第4匝至第6匝线圈可以设置于初级绕组的初级绕组层A2中。
在本申请实施例中，可以使用辅助电源绕组构成电荷平衡绕组，能够提高电源转换电路的噪声抑制的性能，并且节约了平面变压器的成本，提高了平面变压器的空间利用率。
可选地，所述电荷平衡绕组可以设置为环形绕组，对于环形绕组，虽然电荷平衡绕组包括的电荷平衡绕组层的平均电位与相对的次级绕组层的平均电位相同，但电荷平衡绕组层的内外径分布的各匝线圈的长度不同。如果电荷平衡绕组层各匝线圈的匝宽是相同的，则各匝线圈的面积就不同，从而使得各匝线圈对次级绕组层的电容不同，而导致相邻的次级绕组层上的次级线圈的净感应电荷不能完全平衡为零。
可选地，针对上述问题，本申请实施例提出了将电荷平衡绕组层的线圈采用沿内外径各匝宽度逐次变小的方法，以使得电荷平衡绕组层与相邻的次级绕组层之间的电容均匀分布，以减少平面电压器工作时次级绕组层上的净感应电荷。
在一些实施例中，所述第一电荷平衡绕组层中的N匝线圈形成环形绕组，且所述环形绕组中由内至外的第i匝线圈的匝宽大于第i+1匝线圈的匝宽，其中N-1≥i≥1。
在本申请实施例中，电荷平衡绕组层的线圈沿内外径各匝宽度逐次变小，以使得电荷平衡绕组层与相邻的次级绕组层之间的电容均匀分布，从而能够提高噪声抑制的性能。
例如，图16示出了本申请又一实施例的平面变压器100的截面示意图。如图16所示，电荷平衡绕组层B2包括三匝线圈，三匝线圈的匝宽随着平均半径的增大而逐次变小。
在一些示例中，可以设置第一电荷平衡绕组层上的各匝线圈的匝宽，以使得各匝线圈的面积相等，从而使得各匝线圈对相邻的第一次级绕组层的分布电容相同。具体地，所述第一电荷平衡绕组层的第i匝线圈的匝宽可以满足如下条件：
R i＝R i+1*a i+1/a i，             (10)
其中，R i为所述第i匝线圈的平均半径，R i+1为所述第i+1匝线圈的平均半径，a i为所述第i匝线圈的匝宽，a i+1为所述第i+1匝线圈的匝宽。
在本申请实施例中，针对环形绕组，通过设置电荷平衡绕组层的线圈沿内外径各匝的匝宽，以使得各匝线圈的面积相等，从而使得电荷平衡绕组层与相邻的次级绕组层之间的电容均匀分布，能够提高噪声抑制的性能。
可选地，在一些示例中，与第一电荷平衡绕组层相邻的第一次级绕组层设置的线圈为1匝，即B 1＝1。
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。

Claims (15)

  1. 一种平面变压器，其特征在于，包括：
    初级绕组，包括第一初级绕组层，所述绕组层指位于同一平面上的至少一匝线圈；
    次级绕组，包括第一次级绕组层，其中所述次级绕组的第1匝线圈用于连接电源转换电路的次级电路的电位静点；
    电荷平衡绕组，包括第一电荷平衡绕组层，所述第一电荷平衡绕组层设置于所述第一初级绕组层和所述第一次级绕组层之间，且与所述第一初级绕组层、所述第一次级绕组层相邻，所述第一电荷平衡绕组层的一端用于连接所述电源转换电路的初级电路的电位静点，所述第一电荷平衡绕组层包括位于同一平面的N 1匝线圈，在所述平面变压器工作时，所述第一电荷平衡绕组层的N b1匝线圈产生的第一感应电压的平均值与所述第一次级绕组层产生的第二感应电压的平均值相等，其中N 1、N b1为正整数，N 1大于或等于N b1。
  2. 如权利要求1所述的平面变压器，其特征在于，所述第一次级绕组层上设置有所述次级绕组的第N s1匝至第N s1+B 1-1匝线圈，N s1、B 1为正数，N 1、N b1满足如下条件：
    N 1＝N b1+C 1，N b1＝2*N s1+B 1-2，
    其中，C 1为实数，C 1匝线圈至少用于通过产生的感应电压耦合到所述次级绕组的噪声电流平衡所述初级绕组电位跳变通过所述电荷平衡绕组匝间间隙耦合到所述次级绕组的噪声电流。
  3. 如权利要求2所述的平面变压器，其特征在于，C 1的取值范围为[0,1.1*N b1]。
  4. 如权利要求1至3中任一项所述的平面变压器，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，所述第二次级绕组层上设置有所述次级绕组的第N s2匝至第N s2+B 2-1匝线圈，其中，N s2、B 2为正数；
    所述电荷平衡绕组还包括第二电荷平衡绕组层，所述第二电荷平衡绕组层设置于所述第二初级绕组层和所述第二次级绕组层之间，且与所述第二初级绕组层、所述第二次级绕组层相邻，所述第二电荷平衡绕组层的第一端用于连接所述电源转换电路的初级电路的电位静点，所述第二电荷平衡绕组层上设置有N 2匝线圈，其中N 2大于或等于N b2，在所述平面变压器工作时，N b2匝线圈产生的第三感应电压的平均值与所述第二次级绕组层产生的第四感应电压的平均值相等，N 2、N b2为正数。
  5. 如权利要求4所述的平面变压器，其特征在于，N 2、N b1、N b2满足如下条件：
    N 2＝N b2+C 2，N b1＝2*N s1+B 1-2，N b2＝2*N s2+B 2-2，N b2≥N b1，
    其中，C 2为实数，C 2匝线圈至少用于通过产生的感应电压耦合到所述次级绕组的噪声电流平衡所述初级绕组电位跳变通过所述电荷平衡绕组匝间间隙耦合到所述次级绕组的噪声电流。
  6. 如权利要求5所述的平面变压器，其特征在于，C 2的取值范围为[0,1.1*N b2]。
  7. 如权利要求1至6中任一项所述的平面变压器，其特征在于，所述初级绕组包括初级功率绕组，所述第一电荷平衡绕组层的所述第一端和所述初级功率绕组的第一端为同名端，其中，所述初级功率绕组的第一端用于连接所述初级电路的动点。
  8. 如权利要求1至7中任一项所述的平面变压器，其特征在于，所述初级绕组包括 辅助电源绕组，所述第一电荷平衡绕组层上设置的所述N 1匝线圈为所述辅助电源绕组的第1匝至第N 1匝线圈，其中所述辅助电源绕组的第1匝线圈用于连接所述初级电路的工作地。
  9. 如权利要求1至8中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，所述次级绕组设置于所述初级绕组的两侧。
  10. 如权利要求1至9中任一项所述的平面变压器，其特征在于，在所述平面变压器工作时，在所述第一电荷平衡绕组层上设置的所述N 1匝线圈的第二端与任何导体之间不存在电性连接，且与任何元件之间也不存在电性连接。
  11. 如权利要求1至10中任一项所述的平面变压器，其特征在于，B 1＝1。
  12. 如权利要求1至11中任一项所述的平面变压器，其特征在于，所述第一电荷平衡绕组层中的N 1匝线圈形成环形绕组，且所述环形绕组中的第i匝线圈的匝宽大于第i+1匝线圈的匝宽，其中，所述第i匝线圈的平均半径小于所述第i+1匝线圈的平均半径，N 1-1≥i≥1。
  13. 如权利要求12所述的平面变压器，其特征在于，所述第i匝线圈的匝宽满足如下条件：
    R i＝R i+1*a i+1/a i，
    其中，R i为所述第i匝线圈的平均半径，R i+1为所述第i+1匝线圈的平均半径，a i为所述第i匝线圈的匝宽，a i+1为所述第i+1匝线圈的匝宽。
  14. 一种电源转换电路，其特征在于，包括：如权利要求1至13中任一项所述的平面变压器、初级电路以及次级电路，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。
  15. 一种适配器，其特征在于，包括如权利要求14所述的电源转换电路。
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022023910A1 (en) * 2020-07-31 2022-02-03 Silanna Asia Pte Ltd Transformer with interleaved shielding windings

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108364768B (zh) 2017-11-10 2019-11-19 华为技术有限公司 平面变压器、电源转换电路以及适配器
CN113491072B (zh) * 2019-03-29 2022-12-13 华为技术有限公司 一种射频电路和可调变压器
CN110310815A (zh) * 2019-06-14 2019-10-08 华为技术有限公司 平面变压器、电源转换电路以及适配器
CN111181404B (zh) * 2019-07-01 2020-09-18 苏州纳芯微电子股份有限公司 隔离电源芯片
CN110224616A (zh) * 2019-07-02 2019-09-10 淮北市华明工业变频设备有限公司 一种用于高电压中频电源脉冲触发电路的高频链供电装置
CN111312489B (zh) * 2020-02-20 2021-08-17 连云港杰瑞电子有限公司 一种变压器绕组排列方法及其位移电流数值分析方法
CN114068158A (zh) * 2020-07-30 2022-02-18 华为技术有限公司 平面变压器、电源转换电路以及电源适配器
JP2022062571A (ja) * 2020-10-08 2022-04-20 株式会社東芝 電気機器及び電力変換装置
CN114496523A (zh) * 2020-10-28 2022-05-13 华为技术有限公司 平面变压器、电源转换电路及适配器
CN112652470B (zh) * 2020-12-07 2022-11-15 阳光电源股份有限公司 一种变压器
CN116153632A (zh) * 2021-11-22 2023-05-23 广州视源电子科技股份有限公司 电压变换方法、电子设备、平面变压器及其绕组结构

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1239578A2 (en) * 2001-03-08 2002-09-11 Power Integrations, Inc. Method and apparatus for substantially reducing electrical earth displacement current flow generated by wound components
CN201622921U (zh) * 2010-03-19 2010-11-03 Bcd半导体制造有限公司 一种降低反激式变换器共模干扰的变压器及反激式变换器
CN108364768A (zh) * 2017-11-10 2018-08-03 华为技术有限公司 平面变压器、电源转换电路以及适配器

Family Cites Families (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002203718A (ja) * 2000-12-28 2002-07-19 Toko Inc 積層型コモンモードチョークコイル
US7292126B2 (en) 2004-04-30 2007-11-06 Astec International Limited Low noise planar transformer
JP4124814B2 (ja) * 2004-12-06 2008-07-23 株式会社デンソー 入出力絶縁型ｄｃーｄｃコンバータ
JP4736526B2 (ja) 2005-05-11 2011-07-27 パナソニック株式会社 コモンモードノイズフィルタ
US7868724B2 (en) 2006-01-25 2011-01-11 Delta Electronics, Inc. Method for suppressing common mode noise
CN101114541B (zh) 2006-07-28 2011-05-25 台达电子工业股份有限公司 电源转换装置
KR100983033B1 (ko) * 2008-03-17 2010-09-17 삼성전기주식회사 집적화된 트랜스포머 및 이를 이용한 전원 장치
CN103299379B (zh) 2010-11-09 2017-03-29 朴赞雄 用于抵消电气噪声的磁能转移元件和电源
CN103310956B (zh) * 2012-03-06 2016-03-23 台达电子企业管理（上海）有限公司 一种可抑制共模电流的变压器及其功率变换器
CN203013469U (zh) 2012-12-27 2013-06-19 西安芯派电子科技有限公司 降低开关电源emi干扰的变压器及包含该变压器的反激开关电源
US20140292471A1 (en) * 2013-04-02 2014-10-02 Bao Hui Science & Technology Co., Ltd. Transformer
US9589718B2 (en) * 2013-05-07 2017-03-07 Virginia Tech Intellectual Properties, Inc. Method for reducing or eliminating conducted common mode noise in a transformer
CN104183373A (zh) 2013-05-24 2014-12-03 台达电子工业股份有限公司 变压器
US10312012B2 (en) * 2013-08-29 2019-06-04 Solum Co., Ltd. Transformer and power supply device including the same
CN103700484B (zh) 2013-12-05 2015-12-02 西安理工大学 抑制共模emi的开关电源高频变压器辅助绕组设计方法
KR102203090B1 (ko) 2013-12-20 2021-01-14 주식회사 솔루엠 변압기 및 어댑터
CN204651134U (zh) 2013-12-20 2015-09-16 三星电机株式会社 变压器和适配器
KR102047560B1 (ko) * 2014-04-30 2019-11-21 삼성전기주식회사 커먼 모드 필터, 신호 전달 모듈 및 커먼 모드 필터 제조방법
CN204167063U (zh) * 2014-10-08 2015-02-18 深圳市航嘉驰源电气股份有限公司 一种低共模噪声的变压器及充电器
JP6678292B2 (ja) * 2015-02-19 2020-04-08 パナソニックＩｐマネジメント株式会社 コモンモードノイズフィルタ
CN105099205B (zh) 2015-08-12 2017-12-26 矽力杰半导体技术(杭州)有限公司 开关电源、反激式变换器及变压器
CN105047385B (zh) 2015-08-17 2017-06-23 江苏科谷电子有限公司 一种高频变压器及其组成的emi抑制电路
CN105405606A (zh) 2015-11-11 2016-03-16 铜陵瑞博电子科技有限公司 一种改善emi的变压器
US10510477B2 (en) * 2016-01-08 2019-12-17 Semiconductor Components Industries, Llc Planar transformer with multilayer circuit board
CN105609300B (zh) 2016-02-18 2017-06-16 浙江大学 一种反激式开关电源的变压器屏蔽层设计方法
US10141100B2 (en) * 2017-03-24 2018-11-27 Google Llc Common-mode noise reduction

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1239578A2 (en) * 2001-03-08 2002-09-11 Power Integrations, Inc. Method and apparatus for substantially reducing electrical earth displacement current flow generated by wound components
CN201622921U (zh) * 2010-03-19 2010-11-03 Bcd半导体制造有限公司 一种降低反激式变换器共模干扰的变压器及反激式变换器
CN108364768A (zh) * 2017-11-10 2018-08-03 华为技术有限公司 平面变压器、电源转换电路以及适配器

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP3696831A4

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022023910A1 (en) * 2020-07-31 2022-02-03 Silanna Asia Pte Ltd Transformer with interleaved shielding windings
US11605497B2 (en) 2020-07-31 2023-03-14 Silanna Asia Pte Ltd Transformer with interleaved shielding windings

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US20200273617A1 (en) 2020-08-27
US11062837B2 (en) 2021-07-13

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