Resonant circuit and common mode inductor thereof

Abstract

The utility model provides a resonance circuit and a common mode inductor thereof. The common mode inductor comprises a magnetic core, a first winding and a second winding. The magnetic core is provided with a first magnetic core part and a second magnetic core part which are symmetrical relative to a central axis. The first winding wire is wound on the first magnetic core part and forms a first main coil and a first fine tuning coil. The second winding is wound on the second magnetic core part and forms a second main coil and a second fine tuning coil. The first main coil and the second main coil are symmetrical relative to the central axis, the first fine adjustment coil and the second fine adjustment coil are symmetrical relative to the central axis, and a first winding angle formed between the first fine adjustment coil and a normal perpendicular to the central axis and a second winding angle formed between the second fine adjustment coil and the normal are both 0-90 degrees. Wherein a first direction along the normal is defined as 0 degree, and a second direction along the central axis is defined as 90 degrees. According to the utility model, accurate control of leakage inductance can be realized.

Description

Technical Field

[0001] The utility model relates to the technical field of switching power supply products, in particular to a resonant circuit capable of accurately controlling leakage inductance and a common-mode inductor thereof. Background Art

[0002] At present, resonant inductors are widely used in the field of switching power supplies. Resonant inductors are basically used in switching power supplies related to frequency modulation. In small and medium-power switching power supplies, a group of coils are directly wound on the magnetic core to obtain the corresponding differential mode inductance, which is used as a resonant inductor. In a high-power switching power supply, due to the large current flowing through it, the differential mode inductor directly wound in this way can easily reach saturation and lose its magnetism. It cannot cooperate with the resonant capacitor to play a certain role as a resonant cavity, which can easily damage the switching power supply. Therefore, in order not to enter the saturation state, the parasitic leakage inductance of the common mode inductor can be used as the resonant inductor. At the same time, the common mode inductor is also beneficial for suppressing common mode high-frequency noise. However, the leakage inductance of the common mode inductor is not easy to control, the leakage inductance tolerance range is large, and the corresponding resonant frequency will also shift greatly, which greatly affects the normal working mode of the switching power supply. In addition, when the input voltage variation range is wider or the load power is larger, its application range will become abnormal. Therefore, in order to expand the application scope of the product and enhance its reliability under special conditions, it is necessary to study and design the characteristics and influencing factors of leakage inductance and improve its stability, so as to make the whole system more robust and withstand the test of extreme conditions, so as to further improve and approach perfection.

[0003] In view of the above problems, the industry urgently needs a resonant circuit and its common-mode inductor that can not only meet a wider input voltage, but also show wider adaptability at a larger load power, and can effectively solve the above problems and can accurately control the leakage inductance. Utility Model Content

[0004] The purpose of the present invention is to provide a resonant circuit and a common-mode inductor thereof capable of accurately controlling leakage inductance, so as to solve at least one problem raised in the above-mentioned background technology.

[0005] In order to achieve the above-mentioned purpose, the utility model provides a common-mode inductor, which includes: a magnetic core, having a first magnetic core part and a second magnetic core part symmetrical with respect to a central axis; a first winding, wound around the first magnetic core part and forming a first main coil and a first fine-tuning coil; a second winding, wound around the second magnetic core part and forming a second main coil and a second fine-tuning coil; wherein the first main coil and the second main coil are symmetrical with respect to the central axis, the first fine-tuning coil and the second fine-tuning coil are symmetrical with respect to the central axis, and a first winding angle formed between the first fine-tuning coil and a normal perpendicular to the central axis, and a second winding angle formed between the second fine-tuning coil and the normal are both between 0 degrees and 90 degrees, wherein the first direction along the normal is defined as 0 degrees, and the second direction along the central axis is defined as 90 degrees.

[0006] In some embodiments of the present invention, the first winding angle and the second winding angle are in a corresponding relationship with leakage inductance, and as the first winding angle and the second winding angle are closer to the direction of 0 degrees, the leakage inductance increases.

[0007] In some embodiments of the present invention, 2N slots corresponding to different winding angles are arranged on the magnetic core, where N is a positive integer greater than or equal to 1, and the slots are symmetrical with respect to the center axis; the first fine-tuning coil and / or the second fine-tuning coil are wound on the slots.

[0008] In some embodiments of the present invention, the first main coil and the second main coil are multi-turn coils, and the number of turns of the first fine-tuning coil and the second fine-tuning coil is smaller than the number of turns of the first main coil and the second main coil.

[0009] In some embodiments of the present invention, the windings of the first fine-tuning coil and the second fine-tuning coil are wound in parallel.

[0010] In some embodiments of the present invention, the first outlet end of the first winding and the first outlet end of the second winding are outlets along the first side of the central axis; the second outlet end of the first winding and the second outlet end of the second winding are outlets along the second side of the central axis.

[0011] In some embodiments of the present invention, the first output end of the first winding and the first output end of the second winding are at the same output length from the first side of the magnetic core; the second output end of the first winding and the second output end of the second winding are at the same output length from the second side of the magnetic core.

[0012] In some embodiments of the present invention, the first outlet end of the first winding and the first outlet end of the second winding are 6-7 cm away from the first side of the magnetic core.

[0013] In order to achieve the above object, the utility model further provides a resonant circuit, which includes: a bridge circuit and a resonant cavity coupled to the bridge circuit, wherein the resonant cavity includes the common-mode inductor as described above.

[0014] In some embodiments of the present invention, the first main coil and the second main coil of the common-mode inductor are equivalent to an equivalent common-mode inductor, and the first fine-tuning coil and the second fine-tuning coil are equivalent to a first parasitic inductor and a second parasitic inductor, respectively.

[0015] In some embodiments of the present invention, the second output end of the first winding and the second output end of the second winding are twisted in parallel.

[0016] Compared with the prior art, the utility model has the following beneficial effects: the utility model can provide a resonant circuit and common-mode inductor that can accurately control the leakage inductance, which can meet the user's demand for a wider dynamic input voltage range. At the same time, at a larger load power, the resonant circuit of the utility model can show a wider adaptability. Without increasing the cost and selecting another magnetic core, the leakage inductance is controlled in multiple dimensions, which improves the performance of the product in harsh conditions.

[0017] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and other features and advantages of the present invention will become more apparent by describing in detail example embodiments thereof with reference to the attached drawings.

[0019] Figure 1 It is a structural schematic diagram of the resonant circuit of the utility model;

[0020] Figure 2 for Figure 1 Equivalent schematic diagram of the common-mode inductor in;

[0021] Figure 3A It is a structural schematic diagram of the common mode inductor of the utility model;

[0022] Figure 3B Shows from Figure 3A The notch structure observed at the top of the center core;

[0023] Figure 3C Shows from Figure 3A The notch structure observed on the outer side wall of the middle core side column;

[0024] Figure 4 A top view of the output line of the common mode inductor of the utility model;

[0025] Figure 5 Schematic diagram of leakage inductance flux cancellation of rod-shaped magnetic core. DETAILED DESCRIPTION

[0026] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present invention will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their detailed description will be omitted.

[0027] When introducing the elements / components / etc. described and / or illustrated herein, the terms "a", "an", "the", "said", and "at least one" are used to indicate that there are one or more elements / components / etc. The terms "comprising", "including", and "having" are used to indicate an open-ended inclusive meaning and mean that there may be additional elements / components / etc. in addition to the listed elements / components / etc. In addition, the terms "first", "second", etc. in the claims are used only as labels and are not numerical limitations of their objects.

[0028] See also Figure 1 The utility model provides a resonant circuit 100, which may include a bridge circuit 10 and a resonant cavity RC coupled to the bridge circuit, wherein the resonant cavity RC includes a common mode inductor 20 and a resonant capacitor Cr. The specific structure of the common mode inductor 20 of the utility model is as follows: Figures 3A to 3C As shown, it will be described in detail later.

[0029] In some embodiments of the present invention, the bridge circuit 10 may include a first bridge arm 11 and a second bridge arm 12 connected in parallel. The first bridge arm 11 may include a first upper bridge arm 111 and a first lower bridge arm 112 connected in series, and a first bridge arm midpoint N1 is provided between the first upper bridge arm 111 and the first lower bridge arm 112. The second bridge arm 12 may include a second upper bridge arm 121 and a second lower bridge arm 122 connected in series, and a second bridge arm midpoint N2 is provided between the second upper bridge arm 121 and the second lower bridge arm 122. It is understood that in other embodiments, bridge circuits of other structures are also applicable, and the present invention is not limited thereto.

[0030] Combined with reference Figure 3AIn the present invention, the common mode inductor 20 may include a magnetic core 21, a first winding 22, and a second winding 23. The magnetic core 21 may have a first magnetic core portion 211 and a second magnetic core portion 212 that are symmetrical relative to a central axis I. The first winding 22 is wound around the first magnetic core portion 211 and forms a first main coil 221 and a first fine-tuning coil 222. The second winding 23 is wound around the second magnetic core portion 212 and forms a second main coil 231 and a second fine-tuning coil 232. The first main coil 221 and the second main coil 231 are symmetrical relative to the central axis I (for example, Figure 3A The first fine-tuning coil 222 and the second fine-tuning coil 232 are symmetrical with respect to the central axis I (for example, Figure 3A The first fine-tuning coil 222 is symmetrical with respect to the central axis I), and the first winding angle θ1 formed between the first fine-tuning coil 222 and the normal line F perpendicular to the central axis I, and the second winding angle θ2 formed between the second fine-tuning coil 232 and the normal line F are both between 0 degrees and 90 degrees, wherein the first direction along the normal line F (for example Figure 3A The horizontal direction in the center axis is defined as 0 degrees, and the second direction along the central axis I (e.g. Figure 3A The vertical direction in the image is defined as 90 degrees.

[0031] See also Figure 1 and Figure 3A In the present utility model, the first output terminal A of the first winding 22 of the common-mode inductor 20 is the first port as the same-name end (for the convenience of description, it is also referred to as "port A" in the following description) connected to the midpoint N1 of the first bridge arm. The first output terminal B of the second winding 23 of the common-mode inductor 20 is the second port as the same-name end (for the convenience of description, it is also referred to as "port B" in the following description) connected to the midpoint N2 of the second bridge arm. The second output terminal A' of the first winding 22 of the common-mode inductor 20 is the first port as the opposite-name end (for the convenience of description, it is also referred to as "port A'" in the following description) connected to the primary side of the transformer T1. The second output terminal B' of the second winding 23 of the common-mode inductor 20 is the second port as the opposite-name end (for the convenience of description, it is also referred to as "port B'" in the following description) connected to the primary side of the transformer T1. A resonant capacitor Cr is also connected between the primary side of the transformer T1 and the first port or the second port of the opposite-name end. For example, Figure 3A In the embodiment of the invention, the resonant capacitor Cr is connected between the primary side of the transformer T1 and the second port B' of the opposite end. However, it is understood that in other embodiments, the resonant capacitor Cr may also be connected between the primary side of the transformer T1 and the first port A' of the opposite end, which is not a limitation of the present invention. Figure 1In the embodiment of the present invention, the common mode inductor 20 and the resonant capacitor Cr together form the resonant cavity RC, but the present invention is not limited thereto. In other embodiments, the resonant cavity RC may also include other components, which is not a limitation of the present invention.

[0032] Please continue reading Figure 3A In some embodiments of the present invention, the first main coil 221 and the second main coil 231 may be multi-turn coils, and the number of turns of the first fine-tuning coil 222 and the second fine-tuning coil 232 is less than the number of turns of the first main coil 221 and the second main coil 231. For example, FIG. 3 shows that the number of turns of the first main coil 221 and the second main coil 231 is 4 turns, and the number of turns of the first fine-tuning coil 222 and the second fine-tuning coil 232 is 1 turn, but these are not intended to limit the present invention. In other words, according to different design requirements, the number of turns of the first fine-tuning coil 222 and the second fine-tuning coil 232 may also be 2 turns or more. When the number of turns of the first fine-tuning coil 222 and the second fine-tuning coil 232 is multiple turns, the windings of the first fine-tuning coil 222 and the second fine-tuning coil 232 are preferably wound in parallel.

[0033] Please continue reading Figure 3A In the present invention, the first winding angle θ1 and the second winding angle θ2 are in a corresponding relationship with the leakage inductance, and as the first winding angle θ1 and the second winding angle θ2 are closer to the direction of 0 degrees, the leakage inductance increases.

[0034] Preferably, in some embodiments of the present invention, 2N slots corresponding to different winding angles may be provided on the magnetic core 21, where N is a positive integer greater than or equal to 1. Figure 3B and Figure 3C As shown, Figure 3B Shows from Figure 3A The structure of the notch 217 observed at the top 215 of the core, Figure 3C Shows from Figure 3A The structure of the slots 218 observed on the outer side wall 218 of the central magnetic core side column. These slots 217, 218 are symmetrical with respect to the central axis I, and the first fine-tuning coil 222 and / or the second fine-tuning coil 232 can be wound on these slots 217, 218. Figure 3C In FIG. 2 , there are shown slots 218 corresponding to three different winding angles, 0 degree, 15 degree and 30 degree. Figure 3B The figure shows the slots 217 corresponding to four different winding angles of 45 degrees, 60 degrees, 75 degrees and 90 degrees respectively. The first fine-tuning coil 222 and / or the second fine-tuning coil 232 can be better limited by being wound in these slots 217 and 218 corresponding to different winding angles. Figure 3B and Figure 3CThe notches of some specific winding angles are only schematically shown, but it is understandable that notches corresponding to other different winding angles can be set according to actual design requirements, and these are not intended to limit the present invention. Figure 3B and Figure 3C The corresponding relationship between the slots and the winding angles is only schematically shown. Although the spacing between the slots 217 / slots 218 seems to be equal from the figure, it does not mean that the spacing between the slots 217 / slots 218 is equal in reality.

[0035] In some embodiments of the present invention, the first outlet end A of the first winding 22 and the first outlet end B of the second winding 23 are preferably, for example, along a first side of the central axis I (eg Figure 3A The second outlet end A' of the first winding 22 and the second outlet end B' of the second winding 23 are preferably, for example, along the second side (for example, Figure 3A The wire can be connected to the upper side of the cable 24 and can be fixed by, for example, a cable tie 24. However, it is understood that these are not intended to limit the present invention.

[0036] In some embodiments of the present invention, the first outlet end A of the first winding 22 and the first outlet end B of the second winding 23 are located at a distance from the first side (eg Figure 3A The second outlet end A' of the first winding 22 and the second outlet end B' of the second winding 23 are located at a distance from the second side (e.g. Figure 3A The lead length D2 of the upper side of the circuit is consistent.

[0037] exist Figure 1In the illustrated embodiment, the bridge circuit 10 is, for example, a full-bridge topology circuit, which includes, for example, four switch tubes Q1 to Q4, which may be, for example, MOSFETs, but the present invention is not limited thereto. In addition, the first switch tube Q1 and the second switch tube Q2 may, for example, be connected in series to form a first bridge arm 11, and the third switch tube Q3 and the fourth switch tube Q4 may, for example, be connected in series to form a second bridge arm 12. The power supply of the full-bridge topology circuit may be provided by the power supply terminal V_BUS, that is, the first parallel node N3 formed by the first bridge arm 11 and the second bridge arm 12 in parallel is, for example, electrically connected to the power supply terminal V_BUS, and the second parallel node N4 formed by the first bridge arm 11 and the second bridge arm 12 in parallel is, for example, electrically connected to the ground terminal GND. In some other embodiments, the driving end of the first switch tube Q1 and the driving end of the fourth switch tube Q4 may, for example, be driven by the first drive signal PWM1, and the driving end of the second switch tube Q2 and the driving end of the third switch tube Q3 may be driven by the second drive signal PWM2. Furthermore, the first drive signal PWM1 and the second drive signal PWM2 are preferably complementary square wave signals with dead zones, which are used to perform high-frequency inversion on the full-bridge topology. Preferably, these complementary square wave signals can be output by a single-chip microcomputer, but the present invention is not limited thereto. Furthermore, it is understandable that in the case of particularly high power, more MOS tubes can be connected in parallel to form the full-bridge topology circuit, that is, not limited to Figure 1 The four MOS tubes shown in the figure are not intended to limit the present invention.

[0038] exist Figure 1 In the embodiment shown, the common mode inductor 20 of the present invention is, for example, a 4-port network, and its specific structure after winding is as follows: Figure 3A And, when Figure 3A The common mode inductor 20 shown is applied to Figure 1 In the resonant circuit 100 shown, the first output terminal A of the first winding 22 and the first output terminal B of the second winding 23 of the common mode inductor 20 are respectively used as the first port A and the second port B of the same name end and are respectively electrically connected to the first bridge arm midpoint N1 and the second bridge arm midpoint N2; the second output terminal A' of the first winding 22 and the second winding 23 of the common mode inductor 20 are respectively used as the first port A' and the second port B' of the opposite name end and are respectively electrically connected to the primary side of the transformer T1. Among them, the first main coil 221 and the second main coil 231 of the common mode inductor 20 can be equivalent to an equivalent common mode inductor L1, and the first fine tuning coil 222 and the second fine tuning coil 232 of the common mode inductor 20 can be respectively equivalent to a first parasitic inductor Lr_1 and a second parasitic inductor Lr_2.

[0039] Furthermore, if Figure 3AAs shown, the magnetic core 21 of the common-mode inductor 20 is preferably a square-shaped magnetic core, which can be combined with the spatial position of the mechanism and is more convenient for vertical installation and placement. At the same time, the wire diameters of the windings (i.e., the first winding 22 and the second winding 23) on the side columns on the left and right sides of the central axis I can be selected according to the actual instantaneous power and steady-state power. However, it is understandable that the shape of the magnetic core 21 of the common-mode inductor 20 in the present invention is not limited to Figure 3A The square shape shown is also feasible for magnetic cores of other shapes with symmetrical structures relative to the central axis I. In addition, it is also understandable that the magnetic core 21 of the common mode inductor 20 can also have an air gap, which is also not a limitation to the present invention.

[0040] The following will be combined Figure 1 to Figure 5 , the working principle and process of the resonant circuit 100 and the common-mode inductor 20 of the utility model are described in detail.

[0041] Among them, Figure 3A As shown, the cross arm at the upper end of the magnetic core 21 (for example, in the shape of a square) of the common mode inductor 20 can be provided with a plurality of notches 217, 218 (for details, see Figure 3B , Figure 3C ) epoxy resin board, wherein each notch represents the winding angle of the fine-tuning coil wound on the magnetic core, along the first direction of the normal line F (e.g. Figure 3A The horizontal direction in the center axis is defined as 0 degrees, and the second direction along the central axis I (e.g. Figure 3A The vertical direction in the magnetic core 21 is defined as 90 degrees, and each winding angle is in a corresponding relationship with the leakage inductance to a certain extent (for example, a linear relationship). In addition, the first main coil 221 and the second main coil 231 wound on the side columns on the left and right sides of the magnetic core 21 are completely symmetrical, and the first fine-tuning coil 222 and the second fine-tuning coil 232 wound on the cross arm of the magnetic core 21 are also completely symmetrical. As shown in Table 1 below, it shows an example of the corresponding relationship between the leakage inductance of the first fine-tuning coil and the second fine-tuning coil of the common-mode inductor of the utility model at different winding angles (but the utility model is not limited to this). Assuming that the designed target leakage inductance is 5.6μH, the winding angle of the corresponding fine-tuning coil should be wound at 45 degrees, and the best is to be placed in a slot with a corresponding winding angle. The utility model can achieve precise control of different leakage inductances by winding different fine-tuning coils at different winding angles.

[0042] Assuming the tolerance is limited to 0.2μH, the leakage inductance tolerance range is 0.2 / 5.6*100%=3.5%. It can be seen that the leakage inductance tolerance range can be stably controlled by the fine-tuning coil of the common mode inductor of the utility model, which can be much smaller than the existing 5%-10% control range of the resonant inductor. If there is a deviation, it can be calibrated after measurement, so that the value installed on the system can be guaranteed to be relatively accurate.

[0043] Table 1

[0044] 0 degrees 15 degrees 30 degrees 45 degrees 60 degrees 75 degrees 90 degrees First fine-tuning coil 6.8μH 6.2μH 5.7μH 5.6μH 5.5μH 5.1μH 5μH Second fine-tuning coil 6.8μH 6.2μH 5.7μH 5.6μH 5.5μH 5.1μH 5μH

[0045] Combination Figure 2 , explaining the working principle and process of the leakage inductance formation of the common-mode inductor of the present invention. When the same-name terminals of the common-mode inductor are short-circuited, the inductance of the opposite-name terminals is measured, and the inductance at this time is the leakage inductance of the common-mode inductor; or, when the opposite-name terminals of the common-mode inductor are short-circuited, the inductance of the same-name terminals is measured, and the inductance at this time is the leakage inductance of the common-mode inductor. Figure 2 As shown, it shows the equivalent circuit of the common-mode inductor L of the utility model, wherein the first parasitic leakage inductance Lr_1 and the second parasitic leakage inductance Lr_2 are the parasitic leakage inductances of the common-mode inductor L. If the number of winding turns and the winding method are completely consistent, the inductance of the first parasitic leakage inductance Lr_1 and the second parasitic leakage inductance Lr_2 are the same. Connect the first port A and the second port B of the same-name end to the midpoints of the two bridge arms of the full-bridge topology circuit (for example Figure 1 The nodes N1 and N2 in the circuit are connected, and the first port A' and the second port B' of the opposite-name end are connected to the primary side of the transformer T1 and the resonant capacitor Cr respectively. This is equivalent to connecting a resonant inductor made of the leakage inductance of the common-mode inductor 20 in series between the full-bridge topology circuit and the transformer T1, and forming a resonant cavity with the resonant capacitor Cr to realize a full-bridge resonant soft switching circuit. The leakage inductance of the common-mode inductor must be strictly controlled, because the leakage inductance of the resonant inductor made of leakage inductance is very small. If the variation range is slightly larger, it may exceed the tolerance range. However, it is impossible to meet the low tolerance requirements by adjusting the number of turns. The leakage inductance is much larger with one more turn, and the leakage inductance is much smaller with one less turn. Therefore, there must be a precise method to achieve precise control of the leakage inductance.

[0046] Combination Figure 3A, explaining the specific winding process and principle of the common mode inductor of the utility model. On the one hand, the first port A and the second port B of the same-name end (i.e., the first outlet end A of the first winding 22 and the first outlet end B of the second winding 23) can be fixed by means of a cable tie 24 or the like when the wire is output, so that the corresponding windings are not allowed to spread out at the outlet port, and parallel output is achieved. At the same time, the relative position of the cable tie 24 and the magnetic core 21 should also be fixed, so that the leakage inductance can be stabilized and the change amount can be fixed. The first port A' and the second port B' of the opposite-name end (i.e., the second outlet end A' of the first winding 22 and the second outlet end B' of the second winding 23) are also fixed in the above manner when the wire is output, and no further description is given here. On the other hand, the utility model can control its accuracy through the first fine-tuning coil 222 and the second fine-tuning coil 232. Since the winding angles of the first fine-tuning coil 222 and the second fine-tuning coil 232 and the leakage inductance show a certain corresponding relationship between 0 degrees and 90 degrees, these corresponding relationships can be used to accurately control the required leakage inductance. In the present invention, the closer to the 90-degree direction, the smaller the leakage inductance; the closer to the 0-degree direction, the larger the leakage inductance, which can also be explained by Figure 5 The leakage inductance and flux cancellation diagram of the rod-shaped magnetic core shown in the figure can help us understand that the leakage inductances of the two windings cancel each other out. Figure 5 As shown in the figure, the closer the two windings AA' and BB' wound on the rod-shaped magnetic core are, the smaller their leakage inductance is, and the farther they are, the larger their leakage inductance is. Figure 3A The same principle applies to the square-shaped magnetic core shown in the figure. Figure 5 The bar-shaped magnetic core shown can be understood as an infinite magnetic ring. Figure 3A As shown, the main leakage inductance of the common mode inductor 20 can be determined by the number of turns of the main coil wound on the side pole, and the remaining turn can be used as a fine-tuning coil to control its accuracy. Preferably, two turns can also be used as fine-tuning coils to further control its accuracy.

[0047] Combination Figure 4In order to achieve a more precise control effect during system installation, on the basis of the aforementioned need to control the outlet angle and relative position of the winding, further combined with the actual installation position, the outlet length of the winding is controlled as much as possible on one side, for example, the distance between the first port A and the second port B of the same-name end (i.e., the first outlet terminal A of the first winding 22 and the first outlet terminal B of the second winding 23) and the magnetic core 21 is 6-7cm (i.e., D1 = 6-7cm); on the other side, the first port A' and the second port B' of the opposite-name end (i.e., the second outlet terminal A' of the first winding 22 and the second outlet terminal B' of the second winding 23) need to determine the outlet length of the winding according to the size and placement position of the specific product. At the same time, the two wire harnesses of the first port A' and the second port B' of the opposite-name end (i.e., the second outlet terminal A' of the first winding 22 and the second outlet terminal B' of the second winding 23) can be implemented in parallel twisted pair winding, which can further reduce the amount of change.

[0048] In summary, compared with the prior art, the common-mode inductor of the utility model can achieve precise control of leakage inductance, meeting the user's demand for a wider dynamic input voltage range. At the same time, at a larger load power, the resonant circuit of the utility model can show wider adaptability. Without increasing costs and selecting alternative magnetic cores, the leakage inductance of the resonant inductor is controlled in multiple dimensions, which improves the performance of the product in harsh conditions.

[0049] The utility model can better control the leakage inductance through multiple dimensions by controlling the outlet angle and the outlet length of the windings of the same-name end and the opposite-name end, and fine-tuning the winding angle of the coil, and then combining the installation position of the actual product, thereby not only making the application range of the product wider and more adaptable, but also being able to be used in extreme situations, expanding the application occasions, but also improving the reliability of the product.

[0050] When multiple full-bridge modules are connected in parallel to achieve high power output, the inductance of the resonant inductor is very important for controlling the resonant current of each module. The consistency of the resonant inductor inside the parallel module ensures the consistency of the current sharing control. The utility model can meet the power demand under low input voltage conditions, the power output demand under high power conditions, and the current sharing requirement when multiple modules are connected in parallel, achieving a compatible effect.

[0051] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A common mode inductor, characterized in that: include: A magnetic core having a first magnetic core portion and a second magnetic core portion symmetrical with respect to a central axis; A first winding, wound around the first magnetic core portion and forming a first main coil and a first fine-tuning coil; A second winding, wound around the second magnetic core portion and forming a second main coil and a second fine-tuning coil; Among them, the first main coil and the second main coil are symmetrical with respect to the central axis, the first fine-tuning coil and the second fine-tuning coil are symmetrical with respect to the central axis, and a first winding angle formed between the first fine-tuning coil and a normal perpendicular to the central axis, and a second winding angle formed between the second fine-tuning coil and the normal are both between 0 degrees and 90 degrees, wherein the first direction along the normal is defined as 0 degrees, and the second direction along the central axis is defined as 90 degrees.

2. The common mode inductor according to claim 1, characterized in that: The first winding angle and the second winding angle are in a corresponding relationship with the leakage inductance, and as the first winding angle and the second winding angle are closer to the direction of 0 degrees, the leakage inductance increases.

3. The common mode inductor according to claim 2, characterized in that: 2N slots corresponding to different winding angles are arranged on the magnetic core, wherein N is a positive integer greater than or equal to 1, and the slots are symmetrical with respect to the central axis; The first fine-tuning coil and / or the second fine-tuning coil are wound on the notch.

4. The common mode inductor according to claim 1, characterized in that: The first main coil and the second main coil are multi-turn coils, and the number of turns of the first fine-tuning coil and the second fine-tuning coil is smaller than the number of turns of the first main coil and the second main coil.

5. The common mode inductor according to claim 4, characterized in that: The windings of the first fine-tuning coil and the second fine-tuning coil are wound in parallel.

6. The common mode inductor according to claim 1, characterized in that: The first outlet end of the first winding and the first outlet end of the second winding are outlets along the first side of the central axis; The second outlet end of the first winding and the second outlet end of the second winding are outlets along the second side of the central axis.

7. The common mode inductor according to claim 6, characterized in that: The first outlet end of the first winding and the first outlet end of the second winding have the same outlet length from the first side of the magnetic core; The second outgoing wire end of the first winding and the second outgoing wire end of the second winding have the same outgoing wire length from the second side of the magnetic core.

8. The common mode inductor according to claim 7, characterized in that: The first outgoing wire end of the first winding and the first outgoing wire end of the second winding are 6-7 cm away from the first side of the magnetic core.

9. A resonant circuit, characterized in that: include: A bridge circuit and a resonant cavity coupled to the bridge circuit, wherein the resonant cavity comprises the common-mode inductor according to any one of claims 1 to 8.

10. The resonant circuit according to claim 9, characterized in that: The first main coil and the second main coil of the common mode inductor are equivalent to an equivalent common mode inductor, and the first fine tuning coil and the second fine tuning coil are equivalent to a first parasitic inductor and a second parasitic inductor, respectively.

11. The resonant circuit according to claim 9, characterized in that: The second output end of the first winding and the second output end of the second winding are twisted in parallel.

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