CN114050660A - Multi-strand wireless charging coil and capacitance balance compensation device thereof - Google Patents
Multi-strand wireless charging coil and capacitance balance compensation device thereof Download PDFInfo
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- 238000005859 coupling reaction Methods 0.000 claims description 23
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 5
- 239000000126 substance Substances 0.000 claims description 2
- 230000001965 increasing effect Effects 0.000 abstract description 7
- 238000010586 diagram Methods 0.000 description 9
- 230000017525 heat dissipation Effects 0.000 description 8
- 238000000034 method Methods 0.000 description 5
- 230000005540 biological transmission Effects 0.000 description 4
- 229910052802 copper Inorganic materials 0.000 description 4
- 239000010949 copper Substances 0.000 description 4
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- 239000002356 single layer Substances 0.000 description 3
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J50/00—Circuit arrangements or systems for wireless supply or distribution of electric power
- H02J50/005—Mechanical details of housing or structure aiming to accommodate the power transfer means, e.g. mechanical integration of coils, antennas or transducers into emitting or receiving devices
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/28—Coils; Windings; Conductive connections
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/28—Coils; Windings; Conductive connections
- H01F27/2823—Wires
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/42—Circuits specially adapted for the purpose of modifying, or compensating for, electric characteristics of transformers, reactors, or choke coils
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F38/00—Adaptations of transformers or inductances for specific applications or functions
- H01F38/14—Inductive couplings
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J50/00—Circuit arrangements or systems for wireless supply or distribution of electric power
- H02J50/10—Circuit arrangements or systems for wireless supply or distribution of electric power using inductive coupling
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J50/00—Circuit arrangements or systems for wireless supply or distribution of electric power
- H02J50/10—Circuit arrangements or systems for wireless supply or distribution of electric power using inductive coupling
- H02J50/12—Circuit arrangements or systems for wireless supply or distribution of electric power using inductive coupling of the resonant type
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/0042—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries characterised by the mechanical construction
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Computer Networks & Wireless Communication (AREA)
- Charge And Discharge Circuits For Batteries Or The Like (AREA)
- Coils Of Transformers For General Uses (AREA)
Abstract
The invention relates to a multi-strand wireless charging coil and a capacitance balance compensation device thereof, wherein the sectional area of a litz wire in the wireless charging coil is increased by adopting a mode of winding the multi-strand litz wire in parallel; in addition, aiming at the problem of uneven current caused by the difference of parameters such as inductance values and the like among the stranded parallel winding coil strands, an improved coil capacitance balance compensation scheme is provided, the configuration of a compensation capacitor is researched, and a corresponding design scheme is made, so that the current sharing among the stranded litz wires can be realized on the premise of not changing the resonant cavity characteristic of an IPT system and the cost and the volume of the system.
Description
Technical Field
The invention relates to the technical field of wireless charging, in particular to a multi-strand wireless charging coil and a capacitance balance compensation device thereof.
Background
An Inductive Power Transfer (IPT) system is often applied to a high-Power occasion, and the Power modules of the IPT system can be expanded only by electrically connecting the Power modules in series and parallel. However, it is considered that the magnetic field distribution in space affects the system performance in addition to the electrical series-parallel connection due to the specific mechanism of action of the coil. Thus, in a modular IPT system, power boosting of the coil sections can be achieved with a coil having a larger litz wire cross-sectional area.
At present, the mode of increasing the cross-sectional area of the litz wire is usually a single-stranded litz wire with a larger cross-sectional area, the method is simple to implement, but the thickness of the single-stranded litz wire with a larger cross-sectional area in a high-power system is higher, the heat dissipation capacity of a coil wound by single strands is limited, and the method is not beneficial to the integrated design of the coil.
Disclosure of Invention
Based on the above situation in the prior art, an object of the present invention is to provide a multi-stranded wireless charging coil and a capacitance balance compensation device thereof, wherein a parallel winding manner of multi-stranded litz wires is adopted to increase a cross-sectional area of the litz wires in the wireless charging coil, so that the wireless charging coil is suitable for an integrated design and a high-power application of the coil, and the problem of non-uniform current caused by a difference of parameters such as inductance values among the litz wires is solved.
To achieve the above objects, according to one aspect of the present invention, there is provided a multi-strand wireless charging coil comprising at least two strands of litz wire; the litz wires are arranged in parallel, and the winding modes are the same;
the self-inductance values of the litz wires are equal, and the coupling coefficients of the litz wires are close to 1.
Furthermore, the plurality of litz wires are arranged in parallel in a single layer or in a plurality of layers.
Furthermore, the multiple litz wires are closely attached to each other and arranged in parallel, arranged in parallel at equal intervals or arranged in parallel at unequal intervals.
Furthermore, each strand of the multiple strands of litz wires is formed by winding N strands of copper conductors, wherein N is more than or equal to 100.
Further, the wireless charging coil comprises a primary coil and/or a secondary coil.
According to a second aspect of the present invention, there is provided a wireless charging coil, comprising a primary coil and a secondary coil, wherein the primary coil and the secondary coil are the multi-strand wireless charging coil according to the first aspect of the present invention;
and the primary side coil and the secondary side coil are wound in the same way.
According to a third aspect of the present invention, there is provided a current balancing compensation apparatus for a wireless charging coil, comprising a wireless charging coil and an internal connection compensation capacitor; wherein the content of the first and second substances,
the wireless charging coil comprises the wireless charging coil of the second aspect of the invention; the internal connection compensation capacitors comprise a plurality of primary side internal connection compensation capacitors and a plurality of secondary side internal connection compensation capacitors, the number of the primary side internal connection compensation capacitors is the same as the number of strands of litz wires of a primary side coil in the wireless charging coil, and the number of the secondary side internal connection compensation capacitors is the same as the number of strands of litz wires of a secondary side coil in the wireless charging coil.
Furthermore, the plurality of primary side internal connection compensation capacitors are respectively connected with the plurality of strands of litz wires of the primary side coil in the wireless charging coil in series; and the plurality of secondary side internal connection compensation capacitors are respectively connected with the stranded litz wires of the secondary side coil in the wireless charging coil in series.
Furthermore, the sum of the capacitance values of the plurality of primary side internal connection compensation capacitors is the capacitance value of the primary side external connection compensation capacitor.
Furthermore, the sum of the capacitance values of the plurality of secondary side internal connection compensation capacitors is the capacitance value of the secondary side external connection compensation capacitor.
In summary, the invention provides a multi-strand wireless charging coil and a capacitance balance compensation device thereof, wherein the cross-sectional area of litz wires in the wireless charging coil is increased by adopting a parallel winding mode of the multi-strand litz wires, and because the thickness of each litz wire is not high, the height of the coil is reduced, the space utilization rate in the coil is increased, the heat dissipation area is larger, and the heat dissipation of the coil is facilitated; in addition, aiming at the problem of uneven current caused by the difference of parameters such as inductance values and the like among the stranded parallel winding coil strands, an improved coil capacitance balance compensation scheme is provided, the configuration of a compensation capacitor is researched, and a corresponding design scheme is made, so that the current sharing among the stranded litz wires can be realized on the premise of not changing the resonant cavity characteristic of an IPT system and the cost and the volume of the system.
Compared with the prior art, the invention has the following beneficial technical effects:
(1) the coupling structure adopts stranded duplex winding coil, and resonant cavity connecting wire and coil wire all adopt litz wire, and each litz wire is formed by the intertwine of hundreds of thousands of copper conductors of less diameter, effectively avoids the skin effect, and then improves system efficiency.
(2) The current-carrying area of the coil can be improved by adopting a multi-strand parallel winding mode for the wireless charging coil, the mounting height of the coil is reduced, and the integrated design of the coil is facilitated.
(3) The multi-strand parallel winding coil structure enables the heat dissipation area to be larger, and is beneficial to heat dissipation of the coil.
(4) By adopting the improved coil capacitance balance compensation scheme, the current sharing among the multiple strands of litz wires is realized in a wide power range and a wide coupling coefficient range, and the consistency of the transmission power of the system is further ensured.
Drawings
FIG. 1 is a schematic diagram of a multi-strand wireless charging coil according to the present invention;
figure 2 is a schematic circuit diagram of an IPT system employing a multi-strand wireless charging coil;
FIG. 3 is a schematic diagram of a topology structure of a primary and secondary double-strand parallel-wound wireless charging coil current balance compensation device;
fig. 4 is a diagram showing the connection of compensation capacitors before and after current equalization.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings in conjunction with the following detailed description. It should be understood that the description is intended to be exemplary only, and is not intended to limit the scope of the present invention. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present invention.
In order to meet the requirement of partial power lifting of a coil in a wireless charging system of an electric automobile and solve the problem of unbalanced current of a plurality of parallel wound coils, the invention provides a device for expanding the capacity of the multi-strand parallel wound coils and equalizing the current of the multi-strand parallel wound coils in the wireless charging system of the electric automobile, which can realize the requirement of the power lifting of the coil and the current equalization among the plurality of strands of litz wires in a high-power wireless charging occasion, thereby ensuring that the litz wires of a primary coil and a secondary coil have higher current consistency in a wide power range and a wide coupling coefficient range, and enabling the winding scheme of the multi-strand parallel wound coils to be more suitable for a high-power IPT system.
The technical solution of the present invention will be described in detail below with reference to the accompanying drawings. According to one embodiment of the invention, a multi-strand wireless charging coil is provided, comprising at least two strands of litz wire; the litz wires are arranged in parallel, and the winding modes are the same; the self-inductance values of the litz wires are equal, and the coupling coefficients of the litz wires are close to 1. The wireless charging coil can be used for the primary coil and/or the secondary coil. A schematic diagram of a multi-strand wireless charging coil is shown in fig. 1. As shown in fig. 1, taking a coil formed by bifilar litz wires as an example, the bottom coil (on the left side) is a primary coil bifilar litz wire, the top coil (on the right side) is a secondary coil bifilar wire, and the inside of each strand of the primary and secondary coils is formed by winding hundreds of copper wires with smaller diameter, so as to avoid the skin effect. Multiple strands of litz wires can also be adopted to form the wireless charging coil, and the arrangement among the litz wires can adopt single-layer mutual parallel arrangement or multilayer mutual parallel arrangement; can be closely attached to each other and arranged in parallel, arranged in parallel at equal intervals or arranged in parallel at unequal intervals. The distance d between the multi-strand litz wire and the multi-strand litz wire usually satisfies d ≦ min (the cross-sectional width of the multi-strand litz wire, the cross-sectional height of the multi-strand litz wire)/2. The distance is small relative to the whole coil, the influence on the coupling coefficient is negligible, and the distance is always equal in practical application. And aiming at each strand of the multiple strands of litz wires, N strands of copper wires are wound, wherein N is more than or equal to 100.
Also taking the structure in FIG. 1 as an example, lP2S2、hP2S2And SP2S2The circumference, the height and the area of the cross-sectional area of the secondary side double-strand litz wire are respectively, and the transmission distance of the primary and secondary side coils is d. The self-inductance of the double-stranded litz wire of the primary coil is Lp1And Lp2The self-inductance of the whole double-strand primary side presented to the outside is Lp. The self-inductance of the double-stranded litz wire of the secondary coil is Ls1And Ls2The self-inductance presented by the secondary side double-strand whole body is Ls. The coupling coefficient between the two strands of the primary side is kpThe coefficient of coupling between the secondary side pair is ksThe coupling coefficient between the primary side bifilar and the secondary side bifilar is kps. The coupling coefficient of the primary side single strand 1 and the secondary side single strand 1 is kp1s1The coupling coefficient of the primary side single strand 1 and the secondary side single strand 2 is kp1s2The coupling coefficient of the primary side single strand 2 and the secondary side single strand 1 is kp2s1The coupling coefficient of the primary side single strand 2 and the secondary side single strand 2 is kp2s2. For a primary coil, two litz wires are arranged in parallel and wound side by side, so that the coupling coefficient between the two litz wires is close to 1; the two litz wires are tightly attached, so that the positions of the two litz wires relative to the coil on the other side are very close, and the coupling coefficients of the two litz wires and the coil on the other side are also very close; the two litz wires have the same quality and the same winding mode, so that the self-inductance values of the two litz wires are approximately equal. The characteristics and the winding method of the two litz wires of the secondary side coil are the same as those of the primary side coil. The winding directions of the primary coil and the secondary coil can be determined according to actual conditions, and the primary coil and the secondary coil can be wound clockwise or anticlockwise, and can be wound from inside to outside or from outside to insideHowever, it is necessary to ensure that the winding requirements are met by the multi-stranded litz wire in a single coil. For the coil wound by more than two strands of litz wires, the winding requirement is similar to that of double-strand parallel winding, and the multiple strands of litz wires can be arranged in a single layer or multiple layers; the winding can be tightly wound side by side, and can also be wound at equal intervals and can also be wound at unequal intervals. Under the condition that the sectional areas of the coils are the same, the height of the bifilar parallel-wound coil is smaller than that of a single-turn coil, and the thickness is smaller; the total circumference of the sectional area is larger than that of a single-turn coil, and the heat dissipation area is larger. The multiple parallel winding coils are the same, the more the number of strands, the smaller the height of each strand of coil, the larger the total perimeter of the sectional area, but the difference exists in the coupling coefficients among different strands, and the proper number of strands should be selected according to the actual requirement.
According to a second embodiment of the invention, a wireless charging coil is provided, which comprises a primary coil and a secondary coil, wherein the primary coil and the secondary coil adopt the multi-strand wireless charging coil according to the first embodiment of the invention; and the primary side coil and the secondary side coil are wound in the same way. Fig. 2 is a schematic diagram showing a circuit structure of an IPT system using a plurality of strands of wireless charging coils, where self-inductances of the two strands of litz wires of the primary coil are Lp1And Lp2The self-inductance of the double-stranded litz wire of the secondary coil is Ls1And Ls2. The coupling coefficient between the two strands of the primary side is MpThe coupling coefficient between the secondary side double strands is MsThe coupling coefficient of the primary side single strand 1 and the secondary side single strand 1 is Mp1s1The coupling coefficient of the primary side single strand 1 and the secondary side single strand 2 is Mp1s2The coupling coefficient of the primary side single strand 2 and the secondary side single strand 1 is Mp2s1The coupling coefficient of the primary side single strand 2 and the secondary side single strand 2 is Mp2s2. In the IPT system shown in fig. 2, wireless charging coils are adopted between the full-bridge switch inverter circuit at the input end and the full-bridge rectifier circuit at the output end for power transmission, wherein the multi-strand wireless charging coils provided in the embodiment are adopted for power transmission.
According to a third embodiment of the invention, a current balance compensation device of a wireless charging coil is provided, which comprises a wireless charging coil and an internal connection compensation capacitor; wherein the wireless charging coil comprises the wireless charging coil of the second aspect of the inventionA charging coil; the internal connection compensation capacitors comprise a plurality of primary side internal connection compensation capacitors and a plurality of secondary side internal connection compensation capacitors, the number of the primary side internal connection compensation capacitors is the same as the number of strands of litz wires of a primary side coil in the wireless charging coil, and the number of the secondary side internal connection compensation capacitors is the same as the number of strands of litz wires of a secondary side coil in the wireless charging coil. The plurality of primary side internal connection compensation capacitors are respectively connected with the stranded litz wires of the primary side coil in the wireless charging coil in series; and the plurality of secondary side internal connection compensation capacitors are respectively connected with the stranded litz wires of the secondary side coil in the wireless charging coil in series. The sum of the capacitance values of the plurality of primary side internal connection compensation capacitors is the capacitance value of the primary side external connection compensation capacitor; the sum of the capacitance values of the plurality of secondary side internal connection compensation capacitors is the capacitance value of the secondary side external connection compensation capacitor. For example, the primary coil and the secondary coil are respectively formed by winding m litz wires, and the capacitance value of each primary side internal connection compensation capacitor can be 1/m of the capacitance value of the primary side external connection compensation capacitor; the capacitance value of each secondary side internal connection compensation capacitor can be 1/m of the capacitance value of the secondary side external connection compensation capacitor. The relation between the internal compensation capacitor and the external compensation capacitor is taken as an example, the external series compensation capacitor is CpSeries compensation inductance of LprThe whole primary coil externally presents self-inductance LpThe external series compensation capacitor is Cp＝1/ω2(Lp-Lpr) And omega is the switching angular frequency; the secondary side is treated in the same way.
Fig. 3 shows a schematic topology of the primary and secondary double-strand parallel-wound wireless charging coil current equalization compensation device, and still taking the double-strand parallel-wound wireless charging coil as an example, as shown in fig. 3, MpIs the mutual inductance value, M, between the two litz wires of the primary coilsThe mutual inductance value between the two litz wires of the secondary coil is shown. (L)p1-Mp) Is a litz line Lp1Equivalent inductance value of the branch (L)p2-Mp) Is a litz line Lp2The equivalent inductance value of the branch in which the inductor is arranged; (L)s1-Ms) Is a litz line Ls1Equivalent inductance value of the branch (L)s2-Ms) Is a litz line Ls2The equivalent inductance value of the branch. The primary side is externally connected by adopting the design of a split capacitorThe series compensation capacitor is replaced by two internal connection compensation capacitors Cp1、Cp2Capacitor Cp1And litz line Lp1Series connection, capacitor Cp2And litz line Lp2Are connected in series; the secondary side external series compensation capacitor is changed into two internal connection compensation capacitors Cs1、Cs2Capacitor Cs1And litz line Ls1Series connection, capacitor Cs2And litz line Ls2Are connected in series.
The primary side two litz wires have similar inductance, and in order to ensure the resonance state of the resonant cavity to be unchanged, the capacitors C are respectively connected with the two litz wires in seriesp1、Cp2The capacitance value is similar to that of 1/2 of the capacitance value of the compensation capacitor externally connected to the primary side before splitting, and the capacitance values resonate with equivalent inductance values of single-strand coils of the series branch respectively; capacitor C with secondary side respectively connected with two strands of litz wires in seriess1、Cs2The capacitance value is designed in the same way, and can be approximate to 1/2 of the capacitance value of the compensation capacitor externally connected to the split front secondary side and resonates with the equivalent inductance value of the single-strand coil of the series branch.
For the coil wound by m litz wires in parallel, the design method of the compensation capacitor connected in series with each litz wire is the same as that of the double litz wires, if the inductance of the m litz wires is the same, the capacitance value of each capacitor is 1/m of the capacitance value of the external compensation capacitor, and the capacitance value can resonate with the equivalent inductance value of the litz wire of the corresponding branch; if the m litz wire inductances are different, the compensation capacitor is designed according to the value of each litz wire inductance, and the capacitance value of the compensation capacitor is required to generate resonance with the inductance value of the single litz wire connected in series with the compensation capacitor. Taking a primary coil composed of 2 litz wires as an example, the capacitance value of the series compensation capacitor should be designed to satisfy the following formula:
Cp1//Cp2＝Cp
Lp1//Lp2＝Lp
Cp＝1/ω2(Lp-Lpr)
fig. 4 shows a diagram of the connection of the compensation capacitors before and after current equalization. The left side is a capacitance configuration diagram under a conventional coil external series capacitance compensation scheme, and the right side is a capacitance configuration diagram under a bifilar and winding coil current balance compensation scheme. In a high-power IPT system, in order to reduce the voltage stress of a capacitor, a compensation capacitor is composed of a series of small capacitors connected in series and in parallel. The compensation capacitor of the current balance compensation scheme can be obtained only by halving the capacitor in the left scheme, the capacitance value and the connection mode of each small capacitor in the compensation capacitor are unchanged, the total number of the small capacitors is unchanged, and the current sharing among the multiple litz wires of the coil can be realized on the premise of not increasing the cost and the volume of an IPT system.
In summary, the invention provides a multi-strand wireless charging coil and a capacitance balance compensation device thereof, wherein the cross-sectional area of litz wires in the wireless charging coil is increased by adopting a parallel winding mode of the multi-strand litz wires, and because the thickness of each litz wire is not high, the height of the coil is reduced, the space utilization rate in the coil is increased, the heat dissipation area is larger, and the heat dissipation of the coil is facilitated; in addition, aiming at the problem of uneven current caused by the difference of parameters such as inductance values and the like among the stranded parallel winding coil strands, an improved coil capacitance balance compensation scheme is provided, the configuration of a compensation capacitor is researched, and a corresponding design scheme is made, so that the current sharing among the stranded litz wires can be realized on the premise of not changing the resonant cavity characteristic of an IPT system and the cost and the volume of the system.
It is to be understood that the above-described embodiments of the present invention are merely illustrative of or explaining the principles of the invention and are not to be construed as limiting the invention. Therefore, any modification, equivalent replacement, improvement and the like made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention. Further, it is intended that the appended claims cover all such variations and modifications as fall within the scope and boundaries of the appended claims or the equivalents of such scope and boundaries.
Claims (10)
1. A multi-strand wireless charging coil is characterized by comprising at least two strands of litz wires; the litz wires are arranged in parallel, and the winding modes are the same;
the self-inductance values of the litz wires are equal, and the coupling coefficients of the litz wires are close to 1.
2. The wireless charging coil of claim 1, wherein a plurality of litz wire layers are arranged parallel to each other or a plurality of layers are arranged parallel to each other.
3. The wireless charging coil according to claim 1, wherein the plurality of litz wires are closely arranged in parallel, in parallel at equal intervals, or in parallel at unequal intervals.
4. The wireless charging coil of claim 1, wherein each of the plurality of litz wire strands is formed by winding N copper wire strands, N ≧ 100.
5. The wireless charging coil of claim 1, wherein the wireless charging coil comprises a primary coil and/or a secondary coil.
6. A wireless charging coil, which is characterized by comprising a primary coil and a secondary coil, wherein the primary coil and the secondary coil adopt the multi-strand wireless charging coil as claimed in any one of claims 1 to 5;
and the primary side coil and the secondary side coil are wound in the same way.
7. The current balance compensation device of the wireless charging coil is characterized by comprising the wireless charging coil and an internal connection compensation capacitor; wherein the content of the first and second substances,
the wireless charging coil comprising the wireless charging coil of claim 6;
the internal connection compensation capacitors comprise a plurality of primary side internal connection compensation capacitors and a plurality of secondary side internal connection compensation capacitors, the number of the primary side internal connection compensation capacitors is the same as the number of strands of litz wires of a primary side coil in the wireless charging coil, and the number of the secondary side internal connection compensation capacitors is the same as the number of strands of litz wires of a secondary side coil in the wireless charging coil.
8. The current balancing compensation device of claim 7, wherein the plurality of compensation capacitors connected to the primary side are respectively connected to the plurality of litz wires of the primary side coil of the wireless charging coil in series; and the plurality of secondary side internal connection compensation capacitors are respectively connected with the stranded litz wires of the secondary side coil in the wireless charging coil in series.
9. The current balance compensation device according to claim 8, wherein the sum of the capacitance values of the plurality of primary internal compensation capacitors is the capacitance value of the primary external compensation capacitor.
10. The current balance compensation device according to claim 9, wherein the sum of the capacitance values of the plurality of secondary side internal connection compensation capacitors is the capacitance value of the secondary side external connection compensation capacitor.
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| CN112491159A (en) * | 2020-11-17 | 2021-03-12 | 哈尔滨工业大学 | Circuit for balancing current among three parallel-wound wireless power transmission coil strands and parameter design method thereof |
| CN212907355U (en) * | 2020-07-09 | 2021-04-06 | 纵目科技（上海）股份有限公司 | Wireless charging transceiver coil winding structure |
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- 2021-10-13 CN CN202111192920.4A patent/CN114050660A/en active Pending
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| CN112491159A (en) * | 2020-11-17 | 2021-03-12 | 哈尔滨工业大学 | Circuit for balancing current among three parallel-wound wireless power transmission coil strands and parameter design method thereof |
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