CN117411308B - Hybrid filter circuit structure and hybrid filter planar magnetic integration method - Google Patents
Hybrid filter circuit structure and hybrid filter planar magnetic integration method Download PDFInfo
- Publication number
- CN117411308B CN117411308B CN202311709339.4A CN202311709339A CN117411308B CN 117411308 B CN117411308 B CN 117411308B CN 202311709339 A CN202311709339 A CN 202311709339A CN 117411308 B CN117411308 B CN 117411308B
- Authority
- CN
- China
- Prior art keywords
- filter
- magnetic
- inductance
- magnetic core
- core
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 230000010354 integration Effects 0.000 title claims abstract description 40
- 238000000034 method Methods 0.000 title claims abstract description 19
- 238000005070 sampling Methods 0.000 claims abstract description 14
- 238000013461 design Methods 0.000 claims abstract description 13
- 239000003989 dielectric material Substances 0.000 claims abstract description 11
- 239000011162 core material Substances 0.000 claims description 127
- 230000004907 flux Effects 0.000 claims description 32
- 239000003990 capacitor Substances 0.000 claims description 20
- 238000004804 winding Methods 0.000 claims description 16
- 230000008878 coupling Effects 0.000 claims description 15
- 238000010168 coupling process Methods 0.000 claims description 15
- 238000005859 coupling reaction Methods 0.000 claims description 15
- 238000004364 calculation method Methods 0.000 claims description 7
- 230000006698 induction Effects 0.000 claims description 6
- 230000035699 permeability Effects 0.000 claims description 5
- 239000000919 ceramic Substances 0.000 claims description 4
- 101100379079 Emericella variicolor andA gene Proteins 0.000 claims 1
- 230000001629 suppression Effects 0.000 abstract description 21
- 230000005284 excitation Effects 0.000 description 29
- 238000010586 diagram Methods 0.000 description 26
- 238000004088 simulation Methods 0.000 description 7
- 238000004458 analytical method Methods 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- 238000001931 thermography Methods 0.000 description 4
- 238000001914 filtration Methods 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000003475 lamination Methods 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 239000011889 copper foil Substances 0.000 description 1
- 238000013016 damping Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 230000017525 heat dissipation Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 230000003071 parasitic effect Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
- H03H7/01—Frequency selective two-port networks
- H03H7/0115—Frequency selective two-port networks comprising only inductors and capacitors
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/12—Arrangements for reducing harmonics from ac input or output
- H02M1/126—Arrangements for reducing harmonics from ac input or output using passive filters
-
- 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
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/40—Arrangements for reducing harmonics
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Filters And Equalizers (AREA)
Abstract
The invention provides a mixed filter circuit structure and a mixed filter plane magnetic integration method, wherein the selected harmonic filter is an LCL filter, the LCL filter is symmetrically split according to an interference conduction path, the same harmonic suppression capability is ensured, and the EMI suppression capability of the LCL filter is improved; the EMI filter adopts a mode of combining an active EMI filter and a passive EMI filter to improve the EMI suppression capability in the whole frequency band; the inductance coil is integrated into one magnetic core in a planar magnetic integration mode, and the sampling coil of the active EMI filter is integrated into the same magnetic core unit through reasonable design; the dielectric material is inserted between the planar coil layers to further complete the capacitance integration; the integration scheme can greatly reduce the weight and the volume of the filter and improve the power density of the inversion system.
Description
Technical Field
The invention relates to the field of filters, in particular to a hybrid filter circuit structure and a hybrid filter plane magnetic integration method.
Background
In recent years, with the continuous development of wide bandgap semiconductor devices, the switching frequency of switching transistors used in an inverter system can reach hundreds of kHz, and although the efficiency of the system can be improved, the extremely high switching frequency also causes serious electromagnetic interference problems. Aiming at the interference problem in the inversion system, the Total Harmonic Distortion (THD) and electromagnetic compatibility (EMC) of the inversion system are regulated internationally and internationally for maintaining the stability of a power grid and protecting the safety of electric equipment, which is a design index which must be referred to when the inversion system is designed. It is therefore a necessary research content how to better solve the harmonic problem and the electromagnetic interference problem in the inverter system.
In the prior art, a technical scheme is that the inductors of a single-stage EMI filter and a double-stage EMI filter are respectively integrated in the same magnetic core structure through a magnetic integration technology, wherein the integrated structure of the single-stage EMI filter is reduced by 40% in volume, and the integrated structure of the double-stage EMI filter has a better noise suppression effect and is reduced by 4.6% in inductance volume. In another technical scheme, flexible copper foil is adopted to replace copper wire to realize magnetic integration of the magnetic core element, and compared with a filter of a discrete device, the volume is reduced by more than 20%.
In the prior art, in addition to passive EMI filters, active EMI filters with smaller volume and weight have been proposed, but on the one hand, the frequency band limited by noise suppression is narrow, and on the other hand, it is difficult to simultaneously achieve suppression of Common Mode (CM) noise and Differential Mode (DM) noise. The above solution provides a great improvement in terms of EMI suppression and filter volume and weight optimization, but does not consider both harmonic suppression and EMI suppression, so that the prior art only optimizes design from a single harmonic or passive EMI filter or active EMI filter, and does not consider both harmonic and EMI filters, active and passive EMI filters. In addition, most of the existing magnetic integration schemes are designed by using enameled wires, and the integration design of the capacitor is not considered.
Disclosure of Invention
The invention provides a hybrid filter circuit structure and a hybrid filter planar magnetic integration method for solving the problems.
In one aspect, the present invention provides a hybrid filter circuit structure, the hybrid filter circuit structure includes an LCL filter, an EMI filter, and two RC circuit paths, the LCL filter includes a plurality of inductance units and a magnetic core: the inductance units are equally divided into two inductance coils, and the two inductance coils are symmetrically distributed on L lines and N lines of the circuit; a plurality of the inductance units are integrated on the magnetic core; an EMI filter connected with the LCL filter and provided with an operational amplifier; two RC circuit paths connected to the feedback loop of the operational amplifier.
The invention provides a planar magnetic integration method of a hybrid filter, which comprises the following steps:
providing a hybrid filter, sampling the magnetic resistance R of the side column of the magnetic core s Reluctance R of center pillar air gap of magnetic core gc Self-inductance R of a magnetic core coil h Mutual inductance R between left and right magnetic core coils m Magnetic coupling coefficient Kh, common-mode inductance LCM and differential-mode equivalent magnetic resistance Rm_DM of left and right side columns of the magnetic core;
the capacitive integration is obtained by inserting dielectric materials between layers of the planar coil of the LCL filter;
externally connecting a discrete capacitor C with the LCL filter f Inductance L at magnetic core winding side of LCL filter 1 And net side inductance L 2 To obtain corresponding symmetrical split inductances;
connecting an EMI filter to the LCL filter;
by adding dielectric ceramic plates between the L line and the N line of the circuit of the EMI filter, the filter capacitance C required by the EMI filter is obtained X And C Y ;
Inserting a shielding layer between a CM coil and an induction coil of the EMI filter;
according to the reluctance R of the leg of the core s Reluctance R of air gap of center pillar of magnetic core gc Self-induced reluctance R of the core coil h Mutual inductance R between left and right coils of magnetic core m The plane magnetic integration structure of the hybrid filter is designed by the magnetic coupling coefficient Kh of the left and right side posts of the magnetic core, the common-mode inductance value LCM and the differential-mode equivalent magnetic resistance Rm_DMs so as to integrate the capacitor, the split inductance and the filter capacitor C X The filter capacitor C Y Integrated in the core.
Compared with the prior art, the selected harmonic filter is an LCL filter, the LCL filter is split symmetrically according to the interference conduction path, the same harmonic suppression capability is ensured, and the EMI suppression capability of the LCL filter is improved; the EMI filter adopts a mode of combining an active EMI filter and a passive EMI filter to improve the EMI suppression capability in the whole frequency band; the inductance coil is integrated into one magnetic core in a planar magnetic integration mode, and the sampling coil of the active EMI filter is integrated into the same magnetic core unit through reasonable design; the dielectric material is inserted between the planar coil layers to further complete the capacitance integration; the integration scheme can greatly reduce the weight and the volume of the filter and improve the power density of the inversion system.
Drawings
For a clearer description of the technical solutions of the embodiments of the present invention, the drawings that are needed in the description of the embodiments will be briefly introduced below, it being obvious that the drawings in the description below are only some embodiments of the present invention, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art, wherein:
fig. 1 is a schematic diagram of a hybrid filter circuit according to the present invention;
FIG. 2 is an inductance symmetrical structure of the LCL filter shown in FIG. 1;
FIG. 3 (a) is a schematic diagram of an LCL filter circuit under CM noise interference excitation;
FIG. 3 (b) is a schematic diagram of another LCL filter circuit under CM noise interference excitation;
FIG. 4 is a schematic diagram of a winding structure design of a hybrid filter circuit structure;
FIG. 5 (a) is a graph showing the flux path pattern in the core under CM noise excitation in the winding structure of the hybrid filter circuit structure shown in FIG. 4;
FIG. 5 (b) is a graph showing the flux path pattern in the core under DM noise excitation in the winding structure of the hybrid filter circuit structure shown in FIG. 4;
FIG. 6 is a coil integration structure of a hybrid filter circuit structure;
fig. 7 (a) is an LCL filter inductance planar coil lamination;
fig. 7 (b) is a planar coil laminated structure of an EMI filter;
FIG. 8 is a planar magnetic integration structure of a hybrid filter;
FIG. 9 is a schematic diagram of steps of a hybrid filter planar magnetic integration method;
FIG. 10 (a) is a diagram of an equivalent simplified magnetic circuit model under CM noise excitation;
FIG. 10 (b) is a diagram of an equivalent simplified magnetic circuit model under DM noise excitation;
FIG. 11 is a schematic diagram of the magnetic core dimensions of a hybrid filter;
FIG. 12 is a graph of the magnetic flux profile of a common mode inductor under common mode noise excitation;
FIG. 13 is a magnetic flux distribution of L1 under different frequency harmonic excitation;
FIG. 14 is a magnetic flux distribution of L2 under different frequency harmonic excitation;
FIG. 15 (a) is a weight comparison plot of a discrete EMI filter, a hybrid filter, and a discrete LCL filter;
fig. 15 (b) is a volume-versus-volume diagram of a discrete EMI filter, a hybrid filter, and a discrete LCL filter;
fig. 16 (a) is an inverter-side current THD analysis chart of a discrete LCL filter;
fig. 16 (b) is a graph of the network side current THD analysis of the hybrid filter;
fig. 17 (a) is a mixed filter CM noise measurement result;
fig. 17 (b) is a mixed filter DM noise measurement result;
FIG. 18 (a) is a thermal imaging schematic of a hybrid filter;
fig. 18 (b) is a thermal imaging schematic of a discrete LCL filter.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Referring to fig. 1 and fig. 2, fig. 1 is a schematic diagram of a hybrid filter circuit according to the present invention, and fig. 2 is an inductance symmetrical structure of the LCL filter shown in fig. 1.
A hybrid filter circuit structure 100, the hybrid filter circuit structure 100 comprising an LCL filter 10, an EMI filter 20 and two RC circuit paths 30, the LCL filter 10 comprising a plurality of inductorsUnit, magnetic core, inverter circuit, side inductance L 1 Network side inductance L 2 The inductance units are equally divided into two inductance coils, the two inductance coils are symmetrically distributed on an L line and an N line of the circuit, and the effect of the LCL filter on suppressing harmonic waves is equivalent because current flows between the L line and the N line; the output current of the inverter circuit is led into the LCL harmonic filter through the coil of the middle column of the magnetic core; the side inductance L 1 And the net side inductance L 2 Respectively winding the magnetic cores; the side inductance L 1 The net side inductance L 2 The corresponding split inductance is wound N on the upper and lower parts of the magnetic core respectively 2 And N 3 The ring is provided with a magnetic core center post with a length of l g Is arranged between the air gap of the air-bearing device; a plurality of the inductance units are integrated on the magnetic core; the EMI filter 20 is connected to the LCL filter 10, and is provided with an operational amplifier 201; the RC circuit path 30 is connected to the feedback loop of the operational amplifier 201.
The active filter is a current control current source feedback filter, and the control mode adopts analog quantity control. And an operational amplifier is adopted in an amplifying link of the CCCS feedback type active EMI filter, and CM noise signals acquired by the current transformer are reversely amplified. The compensation mode adopts two RC paths, a compensation signal injection line is used for suppressing noise, the current control current source feedback filter comprises a plurality of sampling coils and a plurality of plane coils, the sampling coils are integrated into the magnetic core, and dielectric materials or shielding layers are arranged at intervals on the plane coils.
Referring to fig. 3 (a), fig. 3 (a) is a schematic diagram of an LCL filter circuit under CM noise interference excitation, and fig. 3 (b) is a schematic diagram of another LCL filter circuit under CM noise interference excitation.
VCM represents common mode noise voltage, ZLISN, CM represents LISN equivalent impedance, ZL1+L2 represents side inductance L 1 And net side inductance L 2 Impedance of (c); v (V) 1 And V 2 CM noise voltages generated on LISN by L-line and N-line CM noise after the LCL filter is switched in fig. 3 (a), respectively. V (V) * 1 And V * 2 CM noise voltages generated on LISN by L-line and N-line CM noise after the LCL filter is switched in fig. 3 (b), respectively.
；
When suppressing the CM noise to be converted to DM noise, v1=v2 and v1=v2 should be present. As can be seen from the above calculation formula, the LCL filter of the symmetrical structure can suppress the CM noise from being converted into DM noise.
Referring to fig. 4, fig. 4 is a schematic diagram of a winding structure design of a hybrid filter circuit structure.
Wherein the first line represents L line, the second line represents N line, the LCL filter adopts symmetrical structure, and the LCL filter also comprises an inverter circuit and a side inductor L 1 Network side inductance L 2 The output current is first directed from the coil of the magnetic core into the hybrid filter circuit configuration through the LCL filter. The side inductances L of the inverter are respectively wound on the center posts of the magnetic cores 1 And the net side inductance L 2 The side inductance L 1 The net side inductance L 2 The corresponding split inductance is wound N on the upper and lower parts of the magnetic core respectively 2 And N 3 The ring is provided with a magnetic core center post with a length of l g Is arranged in the air gap.
The EMI filter further comprises a passive filter, wherein the CM inductance coil of the passive filter is wound with N on the left side column of the magnetic core 1 The current transformer induction coil of the active filter is wound on the right column of the magnetic core by 0.5N CT And (5) a ring.
Referring to fig. 5 (a), fig. 5 (a) shows a magnetic flux path distribution diagram in the magnetic core under CM noise excitation in the winding structure of the hybrid filter circuit structure shown in fig. 4. The conducting path direction of the CM noise is the same as that of the L line and the N line, and the coil wound on the left column of the magnetic core and the left column of the magnetic core generates magnetic flux phi under the excitation of CM L And phi R Mutually enhances, presents high impedance to CM noise, and suppresses CM noise. It can be appreciated that the center leg of the magnetic core winds harmonic inductance due to the coilWinding direction is opposite, and magnetic flux phi generated by CM noise excitation C1 And phi C2 The center posts of the magnetic cores cancel each other out, and the influence on CM noise is negligible. Meanwhile, the coil wound around the side post of the magnetic core can generate induced current i under the excitation of CM noise CT Thereby realizing the sampling of the noise signal.
Referring to fig. 5 (b), fig. 5 (b) shows a magnetic flux path distribution diagram in the magnetic core under DM noise excitation in the winding structure of the hybrid filter circuit structure shown in fig. 4.
The side inductance L of the inverter being symmetrical on the center leg of the core under DM noise excitation 1 And the net side inductance L 2 The directions of the generated magnetic fluxes are the same, and the side inductances L 1 And the net side inductance L 2 Respectively and correspondingly generated magnetic fluxes phi C1 And phi C2 Mutually enhances and is used for suppressing certain DM noise. It can be understood that the magnetic fluxes generated by the coils wound on the side posts of the magnetic core under the excitation of DM noise cancel each other out, so that the side posts of the magnetic core are prevented from being saturated. The coil generates almost no induction current due to the mutual cancellation of the side column magnetic fluxes of the magnetic core; even if a small induced current is generated, the coils of the left side column of the magnetic core and the right side column of the magnetic core are of symmetrical structures, and the currents generated by the coils are opposite in reverse directions, so that the currents can be mutually offset in the coils.
Referring to fig. 6, fig. 6 is a coil integration structure of a hybrid filter circuit structure. The coil integration structure of the hybrid filter circuit structure is integrated by the coil of the LCL filter and the coil of the EMI filter.
Referring to fig. 7 (a), fig. 7 (a) shows an LCL filter inductance planar coil lamination structure. Dielectric materials are inserted between the planar coil layers of the LCL filter for realizing capacitance integration. Winding side inductance L on the upper part of the magnetic core of the LCL filter 1 Winding a net side inductance L at the lower part of the magnetic core of the LCL filter 2 To obtain corresponding symmetrical split inductance, at the side inductance L 1 And the net sideInductance L 2 Shielding layers are arranged at intervals. It will be appreciated that the capacitance C of the LCL filter f The method is realized by adopting an external discrete capacitor, and the filter capacitor C of the LCL filter needs to be acquired due to the small capacitance realized by the method of introducing a dielectric material into a planar capacitor and the consideration of an active damping feedback control method adopted by the LCL filter f The current on the upper surface is used as a feedback quantity.
Referring to fig. 7 (b), fig. 7 (b) shows a laminated structure of planar coils of an EMI filter. The dielectric ceramic plates are added between the L line and the N line of the circuit of the EMI filter to obtain filter capacitors CX and CY required by the EMI filter, and a shielding layer is inserted between the CM coil and the induction coil of the EMI filter, so that parasitic parameters between windings are reduced, the noise extraction capacity of an active filtering part is improved, and a good noise suppression effect is maintained.
Referring to fig. 8, fig. 8 is a planar magnetic integrated structure of a hybrid filter. The planar magnetic integrated structure of the hybrid filter is composed of a coil integrated structure of the hybrid filter and a laminated structure of planar coils of the hybrid filter. The LCL filter adopts the side inductance L with symmetrical structure 1 And the net side inductance L 2 The current sampling needs to pass through an external discrete filter capacitor C f Realizing the side inductance L of two symmetrical structures 1 And the net side inductance L 2 Are integrated on the center leg of the magnetic core. The inductance and capacitance required by the passive filtering portion of the EMI filter achieve full integration on the magnetic core, it being understood that CM inductance is wound around the leg of the magnetic core, no additional design of separate DM inductance is required, and the filtering capacitance is also integrated in the same magnetic core structure by dielectric material.
Referring to fig. 9, fig. 9 is a schematic diagram illustrating steps of a hybrid filter planar magnetic integration method.
A planar magnetic integration method for a hybrid filter comprises the following method steps,
s1, providing a hybrid filter, sampling and obtaining magnetic resistance R of a side column of a magnetic core s Reluctance R of center pillar air gap of magnetic core gc Magnetic coreSelf-inductance R of coil h Mutual inductance R between left and right magnetic core coils m Magnetic coupling coefficient Kh, common-mode inductance LCM and differential-mode equivalent magnetic resistance Rm_DM of left and right side columns of the magnetic core;
s2, dielectric materials are inserted between layers of the planar coil of the LCL filter, so that capacitance integration is obtained;
s3, externally connecting a discrete capacitor C to the LCL filter f Inductance L at magnetic core winding side of LCL filter 1 And net side inductance L 2 To obtain corresponding symmetrical split inductances;
s4, connecting an EMI filter with the LCL filter;
s5, adding a dielectric ceramic plate between the L line and the N line of the circuit of the EMI filter to obtain a filter capacitor C required by the EMI filter X And C Y ;
S6, inserting a shielding layer between the CM coil and the induction coil of the EMI filter;
s7, according to the magnetic resistance R of the side column of the magnetic core s Reluctance R of air gap of center pillar of magnetic core gc Self-induced reluctance R of the core coil h Mutual inductance R between left and right coils of magnetic core m The plane magnetic integration structure of the hybrid filter is designed by the magnetic coupling coefficient Kh of the left and right side posts of the magnetic core, the common-mode inductance value LCM and the differential-mode equivalent magnetic resistance Rm_DMs so as to integrate the capacitor, the split inductance and the filter capacitor C X The filter capacitor C Y Integrated in the core.
Referring to fig. 10 (a), fig. 10 (a) is an equivalent simplified magnetic circuit model diagram under CM noise excitation. Side column R of the magnetic core s Part of and center pillar air gap R of the magnetic core gc The reluctance calculation formula of (2) is shown below, wherein R is s ,R y ,R c And R is gc Respectively representing the magnetic resistances of the magnetic core side column, the magnetic yoke, the middle column and the middle column air gap; l (L) s ,l y ,l c And l g The average lengths of the magnetic core side columns, the magnetic yoke, the middle column and the middle column air gaps are respectively; a is that s , A y And A c Cross-sectional areas of side posts, magnetic yoke, center post, mu 0 Is vacuum permeability, mu r Is the relative permeability of the magnetic core:；
it will be appreciated that the self-inductance R of the respective coils is dependent on the magnetic flux path h And mutual inductance R between left and right coils m The calculation formula is shown in the following formula, wherein R h 、R m The self-inductance magnetic resistance of the column coils and the mutual inductance magnetic resistance between the left column coil and the right column coil are respectively represented; rs, ry, rc, rgc the reluctance of the air gaps of the side leg, yoke, center leg and center leg of the core, respectively; r1 represents equivalent magnetic resistance of a side column, an upper half magnetic yoke and a lower half magnetic yoke of the magnetic core; r2 represents the equivalent magnetic resistance of the air gap of the center post of the magnetic core; f represents a common mode magnetomotive force; phi and phi 1 respectively represent the main circuit and side column branch magnetic fluxes of the magnetic core:
。
the formula for calculating the R1 equivalent magnetic resistance and the R2 equivalent magnetic resistance is as follows:
R1=Rs+2Ry；
R2=Rc+2Rgc。
in the above model, it is considered that the coupling coefficient of the magnetic fluxes in the left and right rows is 1, that is, the magnetic fluxes in the left and right rows are completely coupled, but there is a possibility that the leakage magnetic flux Φ2 flows to the middle row in practice. The magnitude of the leakage flux Φ2 is related to the center leg air gap of the magnetic core. As the air gap increases, the R2 equivalent magnetic resistance increases, and the degree of magnetic coupling between the magnetic fluxes of the left and right columns increases, approaching an ideal state. However, when the air gap of the center leg of the magnetic core is too large, the increase in the magnetic resistance of the center leg of the magnetic core further causes an increase in the number of turns of the center leg inductor of the magnetic core, increasing the winding design cost and loss. Therefore, the magnetic coupling coefficient Kh of the left and right side posts is calculated according to the design of the air gap of the middle post of the magnetic core to obtain the turns N1 of the CM coil and the corresponding common-mode inductance coil of the hybrid filterThe relationship is shown in the formula. Wherein Kh represents the magnetic coupling coefficient of the left and right side posts, LCM represents the common mode inductance value, and N1 represents the number of turns of the common mode inductance:。
referring to fig. 10 (b), fig. 10 (b) is an equivalent simplified magnetic circuit model diagram under DM noise excitation. In the above model, the side inductance L of the LCL filter 1 And the net side inductance L 2 The magnetic flux generated by the inductance coils of the center posts of the magnetic core can uniformly flow through the center posts of the magnetic core, and the magnetic flux generated by the coils of the corresponding center posts of the magnetic core is in a full coupling state, and the coupling coefficient is 1. After the proper air gap length is determined by selecting the coupling coefficient of the common mode inductances on the left column and the right column, the inductance turns N2 corresponding to the L1 are determined according to the formula, and the inductance turns N3 corresponding to the L2 are calculated according to the following formula. Wherein rm_dm represents differential mode equivalent magnetic resistance, l1_ L, L1_n represents an L-line inverter side inductance value and an N-line inverter side inductance value of the LCL filter, l2_ L, L2_n represents an L-line net side inductance value and an N-line net side inductance value of the LCL filter, L1 and L2 represent an inverter side inductance total value and a net side inductance total value of the LCL filter, and N2 and N3 represent an L-line (or N-line) inductance turns and a net side L-line (or N-line) inductance turns of the LCL filter, respectively:
。
referring to fig. 11, fig. 11 is a schematic diagram of the magnetic core size of the hybrid filter. And (3) constructing an experimental platform to verify the method, and simulating a winding structure in ANSYS Maxwell software by adopting a finite element method. Selecting l by the above calculation formula g =0.94mm，N 1 =16，N 2 =4 and N 3 =16, selecting the inductance coil turns NCT as CM inductance coil N 1 Is evenly distributed on the left side column and the right side column of the magnetic core for integrated design. The active part selects a working power supply range from + -15V to + -in order to meet the noise suppression effectThe THS4001 type high performance operational amplifier of 2.5V has a gain bandwidth product of 270MHz, a slew rate of above 400V/μs and a settling time of below 30 ns. The sampling resistor selected in the sampling link is r5=100deg.OMEGA, and r2=680 kΩ, r3=3.3kΩ, and r1=10Ω are selected. The dimensions of the magnetic core a= 64.08mm, the magnetic core b=53.77 mm, the magnetic core c=10.24 mm, the magnetic core d=51.24 mm, the magnetic core e=5.32 mm, the magnetic core f=10.36 mm, the experimental platform parameters are shown in table 1, and the parameters of the hybrid filter are shown in table 2:
。
referring to fig. 12, 13 and 14, fig. 12 is a magnetic flux distribution diagram of a common mode inductor under common mode noise excitation, fig. 13 is a magnetic flux distribution diagram of L1 under different frequency harmonic excitation, and fig. 14 is a magnetic flux distribution diagram of L2 under different frequency harmonic excitation.
Since there is no air gap on the leg of the core, it needs to be verified whether CM noise signals will cause magnetic saturation, and the simulation results are shown in fig. 12. It will be appreciated that the output current harmonics of the PWM controlled inverter are concentrated primarily at the switching integer multiple frequencies. When the switching frequency is high, saturation of the core is caused. Referring to fig. 13, harmonic current amplitude is obtained through placs simulation, in an experiment, output voltage frequency f=50 Hz is set, current is 2.45A, and magnetic flux distribution of L1 under harmonic current excitation is obtained through finite element simulation. In another experiment, the output voltage frequency f=200 Hz and the current of 0.24A are set, and the magnetic flux distribution of the L1 under the excitation of harmonic current is obtained through finite element simulation. Referring to fig. 14, harmonic current amplitude is obtained through placs simulation, in an experiment, output voltage frequency f=50 Hz is set, current is 2.45A, and magnetic flux distribution of L2 under harmonic current excitation is obtained through finite element simulation. In another experiment, the output voltage frequency f=200 Hz and the current of 0.24A are set, and the magnetic flux distribution of the L2 under the excitation of harmonic current is obtained through finite element simulation. The CM noise excitation and the harmonic current excitation produce magnetic flux having a saturation magnetic flux density bm=530 mT less than that of the core at both the operating frequency and the switching frequency, which is insufficient to saturate the core.
Referring to fig. 15 (a) and 15 (b), fig. 15 (a) is a weight comparison diagram of a discrete EMI filter, a hybrid filter and a discrete LCL filter, and fig. 15 (b) is a volume comparison diagram of a discrete EMI filter, a hybrid filter and a discrete LCL filter. The planar magnetic integrated structure of the hybrid filter is reduced by 40.90% and 52.44% compared with the structure volumes and weights of the discrete EMI filter and the discrete LCL filter, and the planar magnetic integrated structure of the hybrid filter is more beneficial to the reduction of the inverter volumes and weights.
Referring to fig. 16 (a) and 16 (b), fig. 16 (a) is an inverter-side current THD analysis chart of the discrete LCL filter, and fig. 16 (b) is a net-side current THD analysis chart of the hybrid filter. In order to verify the harmonic suppression effect of the hybrid filter, the inverter output current contains a large number of harmonics, and as shown in fig. 16 (a), the harmonics are mainly concentrated at the switching frequency and the integer multiple thereof, and the inverter side current thd=7.54% does not meet the grid-connected harmonic standard. As shown in fig. 16 (b), after the mixed filter, the grid-side current thd=1.62%, the harmonic wave is significantly suppressed, and the requirement of grid-connected harmonic wave standard can be satisfied, and the harmonic suppression effect of the planar magnetic integration of the mixed filter is verified.
Referring to fig. 17 (a) and 17 (b), fig. 17 (a) is a measurement result of the hybrid filter CM noise, and fig. 17 (b) is a measurement result of the hybrid filter DM noise. After the inverter is connected into the planar magnetic integrated structure of the hybrid filter, the low-frequency suppression effect on CM noise is good, the high frequency is weakened, and the requirements can be met. The mixed filter has good suppression performance on DM noise in the medium frequency band, can generally meet the requirements, and verifies the capability of the mixed filter for suppressing the conducted electromagnetic interference.
Referring to fig. 18 (a) and 18 (b), fig. 18 (a) is a thermal imaging schematic diagram of a hybrid filter, and fig. 18 (b) is a thermal imaging schematic diagram of a discrete LCL filter.
To further verify the reliability of the hybrid filter, the hybrid filter was connected to an inverter circuit and operated at rated power for 10 minutes, it can be seen that in an indoor environment with a background temperature of 23 ℃, the hybrid filter had a temperature rise from 23.6 ℃ to 27.7 ℃, an average temperature of 25.3 ℃, a maximum temperature of 27.7 ℃, a lower temperature than the discrete LCL filter, and an average temperature and a maximum temperature lower than the discrete LCL filter, thanks to the excellent heat dissipation performance of the planar magnetic integration of the hybrid filter. The temperature test result verifies the stability of the planar magnetic integrated structure of the hybrid filter, indirectly verifies that the loss of the integrated inductor is small, and is beneficial to improving the power density of an inversion system.
Compared with the prior art, the selected harmonic filter is an LCL filter, the LCL filter is split symmetrically according to the interference conduction path, the same harmonic suppression capability is ensured, and the EMI suppression capability of the LCL filter is improved; the EMI filter adopts a mode of combining an active EMI filter and a passive EMI filter to improve the EMI suppression capability in the whole frequency band; the inductance coil is integrated into one magnetic core in a planar magnetic integration mode, and the sampling coil of the active EMI filter is integrated into the same magnetic core unit through reasonable design; the dielectric material is inserted between the planar coil layers to further complete the capacitance integration; the integration scheme can greatly reduce the weight and the volume of the filter and improve the power density of the inversion system.
While the invention has been described with respect to the above embodiments, it should be noted that modifications can be made by those skilled in the art without departing from the inventive concept, and these are all within the scope of the invention.
Claims (7)
1. A hybrid filter circuit structure, comprising:
an LCL filter, comprising:
the inductance units are equally divided into two inductance coils, and the two inductance coils are symmetrically distributed on L lines and N lines of the circuit;
a magnetic core, wherein a plurality of the inductance units are integrated on the magnetic core;
an EMI filter connected with the LCL filter and provided with an operational amplifier;
two RC circuit paths connected to the feedback loop of the operational amplifier;
the EMI filter comprises an active filter and a passive filter, wherein the active filter and the passive filter are combined with each other;
the active filter is a current control current source feedback filter, the current control current source feedback filter comprises a plurality of sampling coils and a plurality of plane coils, the sampling coils are integrated into the magnetic core, and dielectric materials or shielding layers are arranged at intervals on the plane coils.
2. The hybrid filter circuit configuration of claim 1 wherein the CM inductor of the passive filter is wound N around the left leg of the core 1 The current transformer induction coil of the active filter is wound on the right column of the magnetic core by 0.5N CT And (5) a ring.
3. The hybrid filter circuit structure of claim 2, wherein the LCL filter comprises:
the output current of the inverter circuit is led into the LCL filter through the coil of the middle column of the magnetic core;
side inductanceL 1 And net side inductanceL 2 The side inductorL 1 And the network side inductanceL 2 Respectively winding the magnetic cores;
the side inductorL 1 The network side inductorL 2 The corresponding split inductance is wound N on the upper and lower parts of the magnetic core respectively 2 Circle and N 3 The ring is provided with a magnetic core center post with the length ofl g Is arranged in the air gap.
4. A planar magnetic integration method of a hybrid filter is characterized by comprising the steps of providing a hybrid filter, sampling and obtaining magnetic resistance of a side column of a magnetic coreR s Reluctance of center post air gap of magnetic coreR gc Self-inductance of magnetic core coilR h Mutual inductance magnetic resistance between left and right magnetic core coilsR m Magnetic coupling coefficient Kh, common-mode inductance LCM and differential-mode equivalent magnetic resistance Rm_DM of left and right side columns of the magnetic core;
capacitive integration is achieved by inserting dielectric material between layers of planar coils of the LCL filter;
externally connecting discrete capacitor with the LCL filterC f Inductance on magnetic core winding side of LCL filterL 1 And net side inductanceL 2 So as to obtain a corresponding symmetrical split inductance;
the LCL filter is connected with the EMI filter;
by adding dielectric ceramic plates between L line and N line of the circuit of the EMI filter, the filter capacitance required by the EMI filter is obtainedC X And a filter capacitorC Y；
A shielding layer is inserted between the CM inductance coil and the current transformer inductance coil of the EMI filter;
according to the reluctance of the leg of the coreR s Reluctance of the center post air gap of the magnetic coreR gc Self-induced reluctance of the core coilR h Mutual inductance magnetic resistance between left and right rows of coils of magnetic coreR m The magnetic coupling coefficient Kh of the left and right side posts of the magnetic core, the common-mode inductance value LCM and the differential-mode equivalent magnetic resistance Rm_DM are used for digitally designing a planar magnetic integration structure of the hybrid filter so as to integrate the capacitor, the split inductor and the filter capacitorC X The filter capacitorC Y Integrated in the core;
calculating the magnetic coupling coefficient Kh of the left and right side posts according to the design of the middle post air gap of the magnetic core to obtain the CM inductance coil of the hybrid filter and the number of turns N of the corresponding common-mode inductance coil 1；
Wherein R is 1 Representing equivalent magnetic resistance of the side column, the upper half magnetic yoke and the lower half magnetic yoke of the magnetic core; r is R 2 Representing the air gap of the center leg of the coreEquivalent magnetic resistance.
5. The hybrid filter planar magnetic integration method of claim 4, wherein the magnetic resistance of the leg of the magnetic coreR s And the magnetic resistance of the center pillar air gap of the magnetic coreR gc The reluctance calculation formula of (2) is as follows:
；
wherein,R s 、R y 、R c andR gc respectively representing the magnetic resistances of the magnetic core side column, the magnetic yoke, the middle column and the middle column air gap;l s 、l y 、l c andl g the average lengths of the magnetic core side columns, the magnetic yoke, the middle column and the middle column air gaps are respectively;A s 、A y andA c the cross sectional areas of the side column, the magnetic yoke and the middle column are respectively,μ 0 is the magnetic permeability of the vacuum and is equal to the magnetic permeability of the vacuum,μ r is the relative permeability of the magnetic core.
6. The hybrid filter planar magnetic integration method of claim 4, wherein the self-induced reluctance of the core coilR h Mutual inductance magnetic resistance between left and right rows of coils of magnetic coreR m The calculation formula of the magnetic coupling coefficient Kh of the left and right side columns of the magnetic core and the common mode inductance value LCM is as follows:
，
；
wherein R is h 、R m The self-inductance magnetic resistance of the magnetic core coil and the mutual inductance magnetic resistance between the left and right magnetic core coils are respectively represented; r is R 1 Representing the edges of the coreEquivalent magnetic resistance of the column, the upper half magnetic yoke and the lower half magnetic yoke; r is R 2 Representing the equivalent reluctance of the center post and center post air gap of the magnetic core; f represents a common mode magnetomotive force; phi, phi 1 And the main path and side column branch magnetic fluxes of the magnetic core are respectively represented.
7. The hybrid filter planar magnetic integration method according to claim 4, wherein the calculation formula of the differential mode equivalent magnetic resistance rm_dm is as follows:
；
wherein L is 1_L 、L 1_N Respectively represent the inductance value of the LCL filter at the side of the L line inverter and the inductance value of the N line inverter, L 2_L 、L 2_N Respectively represent the inductance value of the L line net side and the inductance value of the N line net side of the LCL filter, L 1 、L 2 Respectively represents the total inductance value of the LCL filter inverter side and the total inductance value of the network side, N 2 、N 3 The number of turns of the L-line inductance at the inverter side of the LCL filter and the number of turns of the L-line inductance at the network side are respectively represented.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311709339.4A CN117411308B (en) | 2023-12-13 | 2023-12-13 | Hybrid filter circuit structure and hybrid filter planar magnetic integration method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311709339.4A CN117411308B (en) | 2023-12-13 | 2023-12-13 | Hybrid filter circuit structure and hybrid filter planar magnetic integration method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN117411308A CN117411308A (en) | 2024-01-16 |
| CN117411308B true CN117411308B (en) | 2024-04-02 |
Family
ID=89489369
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311709339.4A Active CN117411308B (en) | 2023-12-13 | 2023-12-13 | Hybrid filter circuit structure and hybrid filter planar magnetic integration method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117411308B (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6549436B1 (en) * | 2002-02-21 | 2003-04-15 | Innovative Technology Licensing Llc | Integrated magnetic converter circuit and method with improved filtering |
| CN102647166A (en) * | 2012-04-18 | 2012-08-22 | 南京航空航天大学 | Inductance-capacitance module for forming plane EMI (Electric-Magnetic Interference) filter |
| CN103208914A (en) * | 2013-03-18 | 2013-07-17 | 南京航空航天大学 | Planar EMI (electromagnetic interference) filter for high-power application |
| US20180269781A1 (en) * | 2017-03-17 | 2018-09-20 | Schaffner Emv Ag | Active filter |
| CN110798165A (en) * | 2019-08-26 | 2020-02-14 | 深圳大学 | Combined filter and manufacturing method thereof |
| CN111987899A (en) * | 2020-08-12 | 2020-11-24 | 中国矿业大学 | LCL-EMI filter decoupling magnetic integration method for single-phase grid-connected converter |
| CN114845462A (en) * | 2022-04-12 | 2022-08-02 | 东南大学 | Plane integrated LCL alternating current filter |
-
2023
- 2023-12-13 CN CN202311709339.4A patent/CN117411308B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6549436B1 (en) * | 2002-02-21 | 2003-04-15 | Innovative Technology Licensing Llc | Integrated magnetic converter circuit and method with improved filtering |
| CN102647166A (en) * | 2012-04-18 | 2012-08-22 | 南京航空航天大学 | Inductance-capacitance module for forming plane EMI (Electric-Magnetic Interference) filter |
| CN103208914A (en) * | 2013-03-18 | 2013-07-17 | 南京航空航天大学 | Planar EMI (electromagnetic interference) filter for high-power application |
| US20180269781A1 (en) * | 2017-03-17 | 2018-09-20 | Schaffner Emv Ag | Active filter |
| CN110798165A (en) * | 2019-08-26 | 2020-02-14 | 深圳大学 | Combined filter and manufacturing method thereof |
| CN111987899A (en) * | 2020-08-12 | 2020-11-24 | 中国矿业大学 | LCL-EMI filter decoupling magnetic integration method for single-phase grid-connected converter |
| CN114845462A (en) * | 2022-04-12 | 2022-08-02 | 东南大学 | Plane integrated LCL alternating current filter |
Also Published As
| Publication number | Publication date |
|---|---|
| CN117411308A (en) | 2024-01-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Chu et al. | A generalized common-mode current cancelation approach for power converters | |
| Heldwein et al. | The three-phase common-mode inductor: Modeling and design issues | |
| Biela et al. | Passive and active hybrid integrated EMI filters | |
| Ali et al. | Integrated active filter for differential-mode noise suppression | |
| EP3136404B1 (en) | Coupling inductor | |
| JP4231857B2 (en) | Noise suppression circuit | |
| TWI497908B (en) | Method of improving performance of wave filter and power conversion device using same | |
| US20080192960A1 (en) | Hybrid Filter for Audio Switching Amplifier | |
| US7898827B2 (en) | Active EMI filtering using magnetic coupling cancellation | |
| CN110798165B (en) | Combined filter and method for manufacturing the same | |
| US6617950B2 (en) | Common mode/differential mode choke | |
| EP3292555A1 (en) | Magnetic structures for filtering amplifier outputs | |
| Jiang et al. | Design of a fully integrated EMI filter for a single-phase grid-connected inverter | |
| Xu et al. | An active EMI choke for both common-and differential-mode noise suppression | |
| CN1871761B (en) | Apparatus and method for noise current reduction in power converters | |
| Masoumi et al. | ${\mathsf\Gamma} $-Source Magnetic Integrated Filter for Single-Phase Grid Tied Voltage Source Converters | |
| US20130162370A1 (en) | Systems and methods for providing an electric choke | |
| Ma et al. | An optimization design of output filter in a grid connected inverter with flexible multilayer foil technique | |
| US20220310303A1 (en) | Coupled inductor winding structure for common-mode noise reduction | |
| Xie et al. | Non-isolated DC-DC converters with low common-mode noise by using split-winding configuration | |
| CN117411308B (en) | Hybrid filter circuit structure and hybrid filter planar magnetic integration method | |
| Lu et al. | Design of planar magnetic integrated LCL-EMI filter for the grid-connected inverter | |
| US11232896B2 (en) | Inductor designs for reducing magnetic interference | |
| Venkatramanan et al. | Integrated higher‐order pulse‐width modulation filter–transformer structure for single‐phase static compensator | |
| CN112041949A (en) | Inductor assembly |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |