CN109639128A - Method of the optimization transformer device structure to reduce inverse-excitation type switch power-supply conduction common mode interference - Google Patents
Method of the optimization transformer device structure to reduce inverse-excitation type switch power-supply conduction common mode interference Download PDFInfo
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- CN109639128A CN109639128A CN201811506346.3A CN201811506346A CN109639128A CN 109639128 A CN109639128 A CN 109639128A CN 201811506346 A CN201811506346 A CN 201811506346A CN 109639128 A CN109639128 A CN 109639128A
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- winding
- transformer
- switch power
- common mode
- excitation type
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/44—Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
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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
- H01F27/34—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
Abstract
A kind of method the invention discloses optimization transformer device structure to reduce inverse-excitation type switch power-supply conduction common mode interference, reduce the parasitic capacitance between them by the physical distance between the armature winding and secondary windings of the transformer in increase inverse-excitation type switch power-supply, reduces conduction common mode interference.This invention removes the partial dislocation electric currents of armature winding side to secondary windings side；And by getting rid of Y capacitance, to limit leakage current, personal safety is protected, prevents user from becoming a part of drain current path, while optimizing system after transformer device structure and good EMI performance can be obtained, reduces cost.The present invention is suitable for field of switch power.
Description
Technical field
The present invention relates to field of switch power, more particularly to a kind of optimization transformer device structure is opened with reducing inverse-excitation type
The method of powered-down source conduction common mode interference.
Background technique
Switching Power Supply is hyundai electronics electric appliance and electronic equipment (such as television set, computer, test equipment, biomedical instrument
Device etc.) heart and power, have many advantages, such as efficiently, environmental protection, safety, it is small in size, have been widely used in communication, military affairs and traffic
Etc. every field.Because rectifying tube, freewheeling diode and power high frequency transformer are essential device in Switching Power Supply, institute
It is determined with their presence and is bound to generate very in the input and output side of Switching Power Supply in the case where switching noise is severe
Strong common mode interference (Common mode interface, CM) and DM EMI (Differential mode interface,
DM)。
Common mode EMI is conducted currently in order to reducing in Switching Power Supply, traditional method is to use Y capacitance as filter element,
Design electromagnetic interface filter.By the high-frequency high-impedance behavior of common mode choke coil inductance, when the normal current in circuit flows through altogether
When mould inductance, electric current generates in the inductance coil of same-phase coiling reversed magnetic field and is cancelled out each other, at this time normal signal electricity
Stream is mainly by coil resistance and on a small quantity because of damping effect caused by leakage inductance.When there is common mode current flowing through coil, due to common mode
The same tropism of electric current can generate magnetic field in the same direction in coil and increase coil induction reactance, and coil is made to show as high impedance, generate compared with
Strong damping achievees the purpose that filtering with this attenuation common-mode electric current.
The shortcomings that prior art: common mode Y capacitance filter element is that low frequency (50Hz) electric current introduces unsafe bypass, performance
For serious leakage current loop, personal safety is had an impact, while limited Y capacitance value also leads to the EMI of whole system
Design complicates, and increases cost.
Summary of the invention
The present invention generates very strong common mode interference for the input terminal and output end that solve Switching Power Supply, while in order to get rid of
Traditional EMI filter element -- the problem of Y type capacitor, providing a kind of optimization transformer reduces inverse-excitation type switch power-supply conduction altogether
The method of mould interference gets rid of traditional EMI filter element -- Y by the transformer device structure of optimization inverse-excitation type switch power-supply
Type capacitor not only can satisfy drain current limit requirement simultaneously but also can reduce the EMI noise in transmission path.
To realize aforementioned present invention purpose, the technical solution adopted is as follows: a kind of optimization transformer device structure is to reduce flyback
The method that formula Switching Power Supply conducts common mode interference, by the armature winding and secondary that increase the transformer in inverse-excitation type switch power-supply
Physical distance between winding reduces the parasitic capacitance between them, reduces conduction common mode interference.
Preferably, by the auxiliary winding of the transformer in inverse-excitation type switch power-supply be placed on armature winding and secondary windings it
Between, armature winding is in the innermost layer of transformer, and auxiliary winding is in the middle layer of transformer, and secondary windings is in the outermost of transformer
Layer.
Further, shield winding, the starting point connection of the shield winding are added between armature winding and auxiliary winding
To one end of the non-close auxiliary winding of armature winding, as B point, the endpoint of shield winding and any electrical node are disconnected.
Beneficial effects of the present invention are as follows: the present invention not only increases armature winding and secondary by adding shield winding
Physical distance between winding, and eliminate armature winding side to secondary windings side partial dislocation electric current；And by getting rid of
Y capacitance to limit leakage current protects personal safety, prevents user from becoming a part of drain current path, optimizes simultaneously
System can obtain good EMI performance again after transformer device structure, reduce cost.
Detailed description of the invention
Fig. 1 is fly-back converter circuit structure.
Fig. 2 is simplified CM Model of Noise Source.
Fig. 3 is predominating path of the CM noise current from primary side to secondary side.
Fig. 4 is the space multistory model being modeled as two adjacent winding layers after the conductor of two hollow shapes.
Fig. 5 is the half-window structural model of the transformer #1 of three different windings.
Fig. 6 is the half-window structural model of the transformer #2 of three different windings.
Fig. 7 is the half-window structural model of the transformer #3 of three different windings.
Specific embodiment:
The present invention will be described in detail with reference to the accompanying drawings and detailed description.
Embodiment 1
A method of optimization transformer device structure is to reduce inverse-excitation type switch power-supply conduction common mode interference, by increasing flyback
Physical distance between the armature winding and secondary windings of transformer in formula Switching Power Supply is electric to reduce the parasitism between them
Hold, reduces conduction common mode interference.
The auxiliary winding of transformer in inverse-excitation type switch power-supply is placed on armature winding and secondary windings by the present embodiment
Between, armature winding is in the innermost layer of transformer, and auxiliary winding is in the middle layer of transformer, and secondary windings is in the outermost of transformer
Layer.
In order to be further reduced displacement current, shield winding, the shielding are added between armature winding and auxiliary winding
The starting point of winding is connected to one end of the non-close auxiliary winding of armature winding, as B point, the endpoint of shield winding and any electrical
Node disconnects.
The present embodiment is by comparing existing flyback transformer and the flyback transformer after present invention optimization
Effect of the invention is proved, as shown in Figure 1, be the circuit structure of existing flyback transformer, in flyback converter, transformation
There are three windings, respectively armature winding, secondary windings and auxiliary winding for device.
In most applications, the CM noise of power inverter is mainly to be generated by the mains ripple of frequency conversion parasitic capacitance
Displacement current is controlled.In isolated power converters, the interwinding capacity of power transformer be CM noise in the converter
Major parasitic capacitances, this capacitance profile is on the winding that different voltages are pulsed.Led to by the CM noise current that noise source generates
The interwinding capacity for crossing transformer is propagated, and enters linear impedance stabilization network (LISN) by the ground line that secondary side exports,
It is illustrated in fig. 2 shown below.
By the mains ripple of winding, total CM noise current between winding is determined, this is depended primarily in transformer terminal
Pulsating volage and transformer winding construction.It can be calculated as follows by the CM noise current that mains ripple introduces:
Parasitic capacitance is distributed between every two layers of winding of three, transformer, for displacement current, between primary winding layers or
Capacitor between armature winding and auxiliary winding layer will not have an impact CM noise, and the capacitor between them is limited in conversion
The primary side of device, these parasitic capacitances only have an impact to DM noise current.Therefore, the displacement current of primary winding will not to auxiliary around
Group CM noise current has an impact.And the distributed parasitic capacitance, auxiliary winding between armature winding and secondary windings and it is secondary around
Distribution capacity between group provides the predominating path of the CM noise current from transformer primary to primary side, following Fig. 3 institute
Show.I in Fig. 3cm_psIt is the propagation path between armature winding and secondary windings, Icm_psIt is between auxiliary winding and primary side
Propagation path.
This method only considers and the related primary side of Y capacitance between them is to primary side.Two adjacent winding layers can
To be modeled as the conductor of two hollow shapes, its center circle shown in Fig. 4 under is identical, and the space between them is filled with absolutely
Edge material, so the parasitic capacitance between them can be calculated by following formula:
Wherein, εrIt is the dielectric constant of interlayer dielectic, Δ l is the height of winding layers, and d is between two winding layers
Distance.
It can be ignored since the capacitor between winding and iron core is smaller, while armature winding does not have shadow to CM noise
It rings, therefore layer capacitance can also be ignored in armature winding, so only considering the capacitor of different winding interlayers.As shown in figure 5, providing
There are three the half-windows of the transformer #1 of different windings for tool.Armature winding is uniformly divided into three layers, meanwhile, auxiliary winding and secondary windings
It is symmetrically distributed in an independent layer.A, D and F is transformer dotted line terminal, by the voltage between two winding layers from
High to Low identification positive current direction.Assuming that positive current direction is from primary side to secondary side, if current direction and positive current side
To on the contrary, then adding a negative sign before total current.
Work as Q1It is V using A point as the amplitude from opening state to off state when in opening stateAPulse voltage
Source can indicate are as follows:
Wherein, VBUSIt is the rectified voltage of inverse excitation type converter, VOIt is the output voltage of inverse excitation type converter, NPAnd NSRespectively
It is the number of turns of armature winding and secondary windings.
Similarly, it is V that D point, which also can be regarded as amplitude,DPulse voltage source from state to off state,
It can indicate are as follows:
Similarly, F point can indicate are as follows:
Wherein: NAIt is the number of turns of auxiliary winding.
Work as Q1When off state, the voltage of A, F and D point is respectively relative to the rising of point B, E and C point.By above equation,
Displacement current propagation path is as shown in the solid arrow in Fig. 3.
So the displacement current between armature winding and secondary windings are as follows:
Wherein: NP1、NP2And NP3It is three primary winding layers from inside to outside, C respectivelyp1s#1、Cp2s#1And Cp3s#1It is respectively
The parasitic capacitance between secondary windings, Δ t are the transient times of voltage jump from inside to outside between three armature windings.
It is as follows that displacement current between auxiliary winding and secondary windings is based on the calculating of identical method:
Wherein Cas#1It is the parasitic capacitance between auxiliary winding and secondary windings.
It is as follows according to the physical distance simplified formula between different winding layers:
(8) formula is substituted into (6) and (7) formula respectively, obtain primary side to secondary side total displacement electric current are as follows:
If total displacement electric current reduces, EMI will be reduced.In order to reduce displacement current, according to formula (2) it is recognized that while
Mains ripple between them is very big, but can be reduced by increasing the physical distance between armature winding and secondary windings
Parasitic capacitance between them.In order to solve this problem, auxiliary winding is placed on middle layer, structure such as Fig. 6 is transformation
Shown in the half-window of device #2.By this method, it is contemplated that the physical distance between different winding layers makes some hypothesis with simplification
Formula:
Therefore, according to above-mentioned analysis method, the total displacement current formula of primary side to secondary side be may be expressed as:
Compare Icm#1And Icm#2, Cas#2Equal to the C of above-mentioned theoryas#1, in NS/NPIn the case where < 17/27, general low
(N in voltage output applicationS< < NP), displacement current substantially reduces.Therefore, by auxiliary winding be placed in armature winding and it is secondary around
The centre of group is the effective ways for reducing CM noise.
In order to further decrease displacement current, it is inserted between armature winding and auxiliary winding based on above-mentioned transformer #2
Shield winding is illustrated in fig. 7 shown below.The starting point of shield winding is connected to B point, and endpoint and any electrical node disconnect.According to similar
Calculation method, the displacement current between armature winding and secondary windings can indicate are as follows:
Displacement current between auxiliary winding and secondary windings is identical as (7) formula:
Additional displacement current is formed, in new power supply architecture, between shield winding and secondary windings to offset displacement
Electric current, calculation formula are as follows:
Wherein Csds#3It is the parasitic capacitance between shield winding and secondary windings.
To put it more simply, can be assumed as follows according to winding interfloor distance parasitic capacitance:
Displacement current I between shield winding and secondary windingscm_sds#3Primary side is flowed to from primary side, there is different electricity
Stream orientation, can eliminate portion of electrical current.Therefore, it can be indicated from the total displacement current formula of primary side and secondary side are as follows:
Compare Icm#3And Icm#2, Ccm#3Equal to C in above-mentioned theorycm#2, Icm#3Much smaller than Icm#2, and displacement current has dropped
It is much lower.Based on the above analysis, shield winding not only increases the physical distance between first winding and secondary winding, and disappears
In addition to the partial dislocation electric current of primary side to secondary side.If selecting suitable shield winding the number of turns Nsd, total displacement electric current is even
It can reduce to zero, to reduce CM noise, obtain better EMI performance.
Obviously, the above embodiment of the present invention be only to clearly illustrate example of the present invention, and not be pair
The restriction of embodiments of the present invention.Any modification done within the spirit and principles of the present invention and changes equivalent replacement
Into etc., it should all be included in the scope of protection of the claims of the present invention.
Claims (3)
1. a kind of method of optimization transformer device structure to reduce inverse-excitation type switch power-supply conduction common mode interference, it is characterised in that: logical
Cross increase inverse-excitation type switch power-supply in transformer armature winding and secondary windings between physical distance come reduce them it
Between parasitic capacitance, reduce conduction common mode interference.
2. optimization transformer device structure according to claim 1 is to reduce the side that inverse-excitation type switch power-supply conducts common mode interference
Method, it is characterised in that: by the auxiliary winding of the transformer in inverse-excitation type switch power-supply be placed on armature winding and secondary windings it
Between, armature winding is in the innermost layer of transformer, and auxiliary winding is in the middle layer of transformer, and secondary windings is in the outermost of transformer
Layer.
3. optimization transformer device structure according to claim 2 is to reduce the side that inverse-excitation type switch power-supply conducts common mode interference
Method, it is characterised in that: shield winding is added between armature winding and auxiliary winding, the starting point of the shield winding is connected to just
One end of the grade non-close auxiliary winding of winding, as B point, the endpoint of shield winding and any electrical node disconnect.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811506346.3A CN109639128B (en) | 2018-12-10 | 2018-12-10 | Method for reducing conducted common-mode interference of flyback switching power supply by optimizing transformer structure |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811506346.3A CN109639128B (en) | 2018-12-10 | 2018-12-10 | Method for reducing conducted common-mode interference of flyback switching power supply by optimizing transformer structure |
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| Publication Number | Publication Date |
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| CN109639128A true CN109639128A (en) | 2019-04-16 |
| CN109639128B CN109639128B (en) | 2021-08-31 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111312489A (en) * | 2020-02-20 | 2020-06-19 | 连云港杰瑞电子有限公司 | Transformer winding arrangement method and displacement current numerical analysis method thereof |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201622921U (en) * | 2010-03-19 | 2010-11-03 | Bcd半导体制造有限公司 | Transformer capable of reducing common-mode interference of flyback converter and flyback converter |
| CN102163492A (en) * | 2010-12-31 | 2011-08-24 | 崧顺电子（深圳）有限公司 | Transformer without Y capacitor and preparation method thereof |
| CN102231318A (en) * | 2011-04-11 | 2011-11-02 | 上海新进半导体制造有限公司 | Method and transformer for reducing common-mode interference in sandwich winding transformer |
| CN202736667U (en) * | 2012-08-28 | 2013-02-13 | 江苏索尔光电科技有限公司 | Switching power supply transformer |
-
2018
- 2018-12-10 CN CN201811506346.3A patent/CN109639128B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201622921U (en) * | 2010-03-19 | 2010-11-03 | Bcd半导体制造有限公司 | Transformer capable of reducing common-mode interference of flyback converter and flyback converter |
| CN102163492A (en) * | 2010-12-31 | 2011-08-24 | 崧顺电子（深圳）有限公司 | Transformer without Y capacitor and preparation method thereof |
| CN102231318A (en) * | 2011-04-11 | 2011-11-02 | 上海新进半导体制造有限公司 | Method and transformer for reducing common-mode interference in sandwich winding transformer |
| CN202736667U (en) * | 2012-08-28 | 2013-02-13 | 江苏索尔光电科技有限公司 | Switching power supply transformer |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111312489A (en) * | 2020-02-20 | 2020-06-19 | 连云港杰瑞电子有限公司 | Transformer winding arrangement method and displacement current numerical analysis method thereof |
| CN111312489B (en) * | 2020-02-20 | 2021-08-17 | 连云港杰瑞电子有限公司 | Transformer winding arrangement method and displacement current numerical analysis method thereof |
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| CN109639128B (en) | 2021-08-31 |
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