CN108461264B - Wireless power transmission loose magnetic coupling transformer device with large offset fault tolerance range and circuit thereof - Google Patents
Wireless power transmission loose magnetic coupling transformer device with large offset fault tolerance range and circuit thereof Download PDFInfo
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- H01F38/00—Adaptations of transformers or inductances for specific applications or functions
- H01F38/14—Inductive couplings
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- H—ELECTRICITY
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- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/24—Magnetic cores
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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
- H01F27/24—Magnetic cores
- H01F27/255—Magnetic cores made from particles
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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
- H01F27/28—Coils; Windings; Conductive connections
- H01F27/32—Insulating of coils, windings, or parts thereof
- H01F27/324—Insulation between coil and core, between different winding sections, around the coil; Other insulation structures
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/34—Special means for preventing or reducing unwanted electric or magnetic effects, e.g. no-load losses, reactive currents, harmonics, oscillations, leakage fields
- H01F27/36—Electric or magnetic shields or screens
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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
- H02J50/70—Circuit arrangements or systems for wireless supply or distribution of electric power involving the reduction of electric, magnetic or electromagnetic leakage fields
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Abstract
The invention discloses a wireless power transmission loose magnetic coupling transformer device with large offset fault-tolerant range and a circuit thereof, wherein the device comprises a transmitting module, a receiving module and a shielding mechanism, the transmitting module and the receiving module comprise an insulating plate made of insulating materials, a strip-shaped magnetic core fixed by the insulating plate and a transformer coil made by winding a plurality of litz wires in parallel, and the coil is wound on the upper surface and the lower surface of the insulating plate to form a spiral structure or wound on one side to form a single-sided staggered structure; the shielding mechanism plays a role in magnetic flux leakage shielding by the metal plate at the back of the coil. The double-sided spiral coil structure and the double-path staggered coil structure are respectively used on the primary side and the secondary side of the transformer, and the double-path staggered coils are connected in parallel through the external circuit, so that the primary side and the secondary side can realize relatively high coupling coefficient and high overall efficiency under the conditions of dead alignment and large deviation, and have small electromagnetic interference, so that the double-sided staggered coil structure can be widely applied to wireless charging systems of electric vehicles with different power levels.
Description
Technical Field
The invention belongs to the technical field of wireless power transmission, and particularly relates to a wireless power transmission loose magnetic coupling transformer device and a circuit thereof, wherein the wireless power transmission loose magnetic coupling transformer device is applied to an electric vehicle and has a large wireless charging offset fault tolerance range.
Background
The non-contact electric energy transmission mainly utilizes the principle of magnetic field coupling to realize power transmission and further realize wireless charging of the electric automobile, namely, a transformer with completely separated primary and secondary sides and loose magnetic coupling is adopted to transmit power from one side of a transmitting device to one side of a receiving device through space induction through high-frequency magnetic field coupling. The wireless charging mode does not need the connection of physical lines, can effectively avoid short circuit, the open circuit danger that environmental factor caused, also is applicable to some severe charging environment more, like mine field operation, sleet weather etc. consequently has higher factor of safety. Under the global environment of energy saving and environmental protection, the wireless charging technology can overcome a plurality of problems existing in the existing contact charging, and can reduce the volume of the vehicle-mounted battery, so that the vehicle-mounted battery is cleaner, more efficient and safer, and has good development prospect.
Compared with contact charging, the biggest defect of wireless power transmission is that a transformer with loose magnetic coupling has larger leakage inductance, the coupling coefficient is not high under the condition that the primary side and the secondary side are opposite, and particularly, the coupling coefficient of the transformer is rapidly reduced under the condition that a coil on the vehicle-mounted secondary side deviates, so that the overall efficiency of a system is not high, and the popularization and application of wireless power transmission are greatly restricted. The main factor limiting the efficiency of the wireless power transmission system is the loss of the loose magnetic coupling transformer, and the improvement of the coupling coefficient of the primary side and the secondary side of the transformer has a critical influence on the reduction of the loss of the transformer. In addition, different from application occasions such as a mobile phone charging platform and the like, for a wireless power transmission system of an electric automobile, the distance between the primary side and the secondary side of the transformer is generally 100 mm-250 mm, and the primary side and the secondary side of the transformer usually have a certain distance offset, and the typical value is 0-300 mm. Therefore, under the condition that the primary side and the secondary side are opposite and have larger deviation, how to improve the coupling coefficient of the loose magnetic coupling transformer and minimize the volume and electromagnetic radiation of the whole system becomes a core problem of research.
Due to volume and space limitations, in order to obtain a higher coupling coefficient, a loose magnetic coupling transformer generally adopts a planar structure, and a magnetic core material with high magnetic permeability is used for controlling a circulation path of a magnetic field. The larger the primary and secondary windings and the larger the core size compared to the spacing between the primary and secondary sides of the transformer, the better the coupling, but at the same time the system size, weight and cost are increased. When the primary and secondary windings and the magnetic core are fixed in size, how to reasonably arrange the shapes and the numbers of the windings and the magnetic core to achieve a higher coupling situation becomes a research hotspot. Based on the above research ideas, related documents provide various design schemes of loose magnetic coupling transformer structures, which can be roughly divided into optimization of a magnetic core and optimization of a coil: as shown in fig. 1, the optimization of the magnetic core is included, and fig. 1 only shows a corresponding magnetic core structure, which adopts more magnetic cores as a magnetic conduction path, so as to enhance the coupling condition between the primary side and the secondary side of the transformer; as shown in fig. 2 and 3, the coil is optimized, the solenoid structure in fig. 2 is a double-sided coil transformer structure suitable for wireless power transmission, and this structure has the advantages that the coupling characteristics of the primary and secondary sides of the transformer are good, the coupling drop is small under certain deviation condition, but the magnetic leakage at the back is large, which causes serious electromagnetic radiation problem, and usually requires to add a metal plate for shielding; the DD-type coil structure in fig. 3 belongs to a single-sided coil transformer structure, and has no back magnetic leakage problem, and the magnetic field direction has directivity, but because there is a "zero coupling point" along the long axis direction, the coupling performance of the structure under a certain offset condition is poor, and in fig. 3, an insulating plate for supporting, two adjacent D-type coils and a magnetic core formed by splicing strips are sequentially arranged from outside to inside.
In summary, for the application occasions in the field of wireless power transmission nowadays, the main problems of the current technologies are: on the premise of not increasing the primary and secondary side volumes of the transformer, the coupling coefficient between the transmitting coil and the receiving coil is lower, and the electric energy transmission efficiency is also lower; especially when the original secondary side is shifted, the coupling coefficient is rapidly reduced, and usually when the shift distance of the original secondary side exceeds 1/3 of the size of the original secondary side, the coupling coefficient is reduced to a level which cannot normally transmit power. Therefore, how to realize that the primary side and the secondary side of the transformer can keep relatively high coupling coefficient under the conditions of positive alignment and deviation is a key problem solved by the invention.
Disclosure of Invention
In view of the above, the present invention provides a wireless power transmission loose magnetic coupling transformer device with a large offset fault tolerance range and a circuit thereof, which can maintain a relatively high coupling coefficient and a high system transmission efficiency under the conditions of primary and secondary sides of the transformer facing each other and a large offset (including lateral and longitudinal), and simultaneously maintain a low electromagnetic radiation intensity.
A wireless power transmission loose magnetic coupling transformer device with a large offset fault tolerance range comprises a transmitting module, a receiving module and two shielding metal plates, wherein the transmitting module and the receiving module are mutually coupled; the transmitting module is arranged on the ground surface, and the receiving module is arranged on a chassis of the vehicle body; the transmitting module and the receiving module are nested in the corresponding shielding metal plates;
the transmitting module and the receiving module respectively comprise two insulation plates, a magnetic core and a coil, the magnetic core is fixedly bonded between the two insulation plates, the coil is in a spiral structure by being bundled and wound along the two insulation plates or is in a single-face staggered structure by being wound on one side of the two insulation plates for two groups respectively, the two groups of coils in the single-face staggered structure realize decoupling by adjusting relative positions, and the two groups of coils realize parallel connection through an external circuit.
When the coil in the transmitting module adopts a single-side staggered structure and the coil in the receiving module adopts a spiral structure, the transformer device adopts primary-side two-path power input and secondary-side one-path power output; on the contrary, the transformer device is a primary side single-path power input, and a secondary side two-path power output.
The coils of the spiral structure are distributed on two sides of the magnetic core in a spiral shape and are evenly distributed along the direction of the magnetic circuit.
The two groups of coils with the single-face staggered structure are distributed on the same side of the magnetic core, and the two groups of coils are arranged in a way that physical decoupling is realized between the two groups of coils, namely mutual inductance between the two groups of coils is approximately zero, and the arrangement modes of the two groups of coils are mutually overlapped.
Furthermore, the insulating plate is realized by adopting a bakelite plate (phenolic resin material), an epoxy plate (epoxy resin material), an organic glass plate (polymethyl methacrylate polymer material), a glass fiber reinforced plastic plate (glass fiber reinforced plastic material) or other insulating materials with higher hardness, and is used for enhancing the strength of the device and fixing the magnetic core.
Further, the magnetic core is the monoblock magnetic core or adopts the thin form bar magnetic core of platyzization to be array arrangement concatenation to form.
Further, the magnetic core is made of ferrite, amorphous, microcrystalline, permalloy, magnetic powder core or at least 2 of the materials.
Furthermore, the coil is formed by winding two or more strands of litz wires, copper strips or copper tubes in parallel, and the number of parallel turns is determined by the current and power grade of the primary side and the secondary side.
Further, the shielding metal plate is made of copper, aluminum, silver or other metal materials with good conductive performance but no magnetic conductivity, and the shielding metal plate can be in a grid shape to achieve a good shielding effect.
A circuit matched with the transformer device comprises a direct current power supply, an inversion module and a rectification module, wherein the direct current side of the inversion module is connected with the output side of the direct current power supply or a preceding stage rectifier, and the alternating current side of the inversion module is connected with a coil in a transmitting module through an impedance matching network; the alternating current side of the rectification module is connected with a coil in the receiving module through an impedance matching network, and the direct current side of the rectification module is connected to a load through a direct current conversion circuit;
if the coils in the transmitting module are in a single-side staggered structure, two groups of coils are respectively connected with two inversion modules through respective impedance matching networks, and the direct current sides of the two inversion modules are connected in parallel and then connected to a direct current power supply or the output side of a preceding stage rectifier to realize power input; if the coil in the receiving module is in a spiral structure, the coil is connected with the rectifying module through the impedance matching network, and the direct current side of the rectifying module is connected to a load through the direct current conversion circuit;
if the coils in the receiving module are in a single-side staggered structure, two groups of coils are respectively connected with two rectifying modules through respective impedance matching networks, and the direct current sides of the two rectifying modules are connected in parallel and then connected to a load through a direct current conversion circuit to realize power output; if the coil in the transmitting module is of a spiral structure, the coil is connected with the inverter module through the impedance matching network, and the direct current side of the inverter module is connected to the direct current power supply or the output side of the pre-stage rectifier.
The circuit realizes the offset fault tolerance of coil coupling through matching with a transformer device, and further realizes that the primary side and the secondary side of the transformer can keep higher coupling coefficient under the conditions of offset and direct alignment.
The staggered coil structure in the transformer device is composed of two mutually decoupled coils, so that two corresponding paths of power input or two corresponding paths of power output can be respectively controlled without being influenced by mutual inductance; on the basis, the coil size, the magnetic core size and the corresponding arrangement mode of the spiral coil structure and the staggered coil structure are optimized, so that the primary and secondary side coils of the transformer have higher coupling coefficients under the condition of dead against; meanwhile, when certain transverse deviation or longitudinal deviation occurs, the coupling between one path of coil and the coil of the spiral structure in the staggered coil structure is weakened while the coupling between the other path of coil is strengthened, and the parallel connection structure is carried out on the direct current side through the corresponding input or output circuit, so that the deviation fault tolerance of the coil coupling is realized, the overall coupling condition of the primary coil and the secondary coil is greatly improved, and a relatively high coupling coefficient can be realized in the deviation range of 1/2 self size.
Therefore, the transformer device can realize relatively high coupling coefficient and high overall efficiency under the conditions that the primary side and the secondary side of the transformer are opposite and have large offset, has small electromagnetic interference due to the electromagnetic shielding device, and can be widely applied to electric automobile wireless charging systems with different power levels.
Drawings
Fig. 1 is a schematic diagram of a loose magnetic coupling transformer structure (core portion) optimized for a core.
Fig. 2 is a schematic diagram of a solenoid-type loose magnetic coupling transformer structure with optimized coils.
Fig. 3 is a schematic structural diagram of a DD type loose magnetic coupling transformer for optimizing a coil.
Fig. 4 is a schematic diagram of an implementation structure of the loose magnetic coupling transformer device for wireless power transmission of an electric vehicle according to the present invention.
Fig. 5 is a schematic circuit diagram of the transformer apparatus shown in fig. 4.
Fig. 6 is a schematic view showing the structure of the magnetic core and the insulating plate inside the transmitting and receiving unit in the loose magnetic coupling transformer of the present invention.
Fig. 7 is a schematic structural diagram of another embodiment of the invention applied to a wireless power transmission loose magnetic coupling transformer device of an electric vehicle.
Fig. 8 is a schematic circuit diagram of the transformer apparatus shown in fig. 7.
Detailed Description
In order to more specifically describe the present invention, the following detailed description is provided for the technical solution of the present invention with reference to the accompanying drawings and the specific embodiments.
The first embodiment is as follows:
in this embodiment, the loose magnetic coupling transformer is composed of a primary side as a transmitting side and a secondary side as a receiving side, and both the primary side and the secondary side include a loose magnetic coupling transformer portion and a corresponding circuit portion.
Fig. 4 is a structure of a loose magnetic coupling transformer for wireless power transmission, which includes a transmitting end metal plate 130, a transmitting end insulating plate 140, a transmitting end magnetic core 120, a transmitting end coil 110, a receiving end metal plate 230, receiving end coils 210 and 211, a receiving end magnetic core 220, and a receiving end insulating plate 240. The transmitting and receiving device of the loose magnetic coupling transformer is formed by winding a plurality of strands of litz wires in parallel, and particularly, in the embodiment, a transmitting end coil 110 is uniformly wound on the upper surface and the lower surface of an insulating plate; the receiving end coils 210 and 211 are wound on one side of the insulating plate in a staggered manner, and the coil positions are arranged in a manner that the two coils realize physical decoupling, that is, the mutual inductance between the two coils is approximately zero. In addition, the transmitting end metal plate 130 and the receiving end metal plate 230 are made of aluminum materials to shield electromagnetic radiation; the transmitting end insulating plate 140 and the receiving end insulating plate 240 are made of plastic, wood or epoxy plate materials to perform insulating and fixing functions; the ferrite material selected by the transmitting end magnetic core 120 and the receiving end magnetic core 220 plays a role in guiding a magnetic circuit, enhances the coupling coefficient between the primary side and the secondary side of the transformer, and can play a certain shielding role.
For the circuit part of this embodiment, as shown in fig. 5, since the transmitting side of the loose magnetic coupling transformer adopts a spiral coil structure wound on both sides, the primary coil is connected to one inverter circuit module after passing through the transmitting side impedance matching network, and the input of the inverter circuit module is connected to the dc power supply to realize power input; because the receiving side of the loose magnetic coupling transformer adopts a staggered coil structure wound on a single side, two secondary side coils are respectively connected to two rectifier circuit modules 1 and 2 after passing through the receiving side impedance matching networks 1 and 2, and the outputs of the two rectifier circuit modules are connected in parallel and then connected with a load through a direct current conversion circuit, so that power output is realized. The coupling compensation of the coil can be realized through the matching of the circuit structure and a loose magnetic coupling transformer, and then the high coupling coefficient can be kept under the conditions that the primary side and the secondary side of the transformer are opposite and offset.
For the application of wireless power transmission of electric vehicles, the primary side of the loose magnetic coupling transformer is generally placed at a relatively fixed position, such as buried under the ground of a road or below a parking space, while the secondary side, i.e., the receiving side, is generally placed at the ground of the electric vehicle, and is used as an energy interface for injecting the vehicle-mounted battery and external power. For the design of a loose magnetic coupling transformer, the working frequency of the loose magnetic coupling transformer is generally selected from a frequency range of 20kHz to 100kHz, the typical value is 85kHz, the working frequency is the working frequency of a transformer primary side inverter (in practical application, the working frequency is usually finely adjusted to optimize the resonance state of a system), under the excitation of alternating current at the frequency, an alternating magnetic field is induced near a coil of a transformer primary side, according to the electromagnetic induction principle, the alternating magnetic field induces a voltage signal on a secondary side of the loose magnetic coupling transformer, the specific action rule is determined by faraday electromagnetic induction law, the voltage signal acts on the secondary side of the transformer to generate a high-frequency current signal, and the conversion process of the whole wireless power transmission 'electric energy-magnetic field-electric energy' is realized through a secondary side rectifier.
In the process of energy conversion, the coil on the primary side and the secondary side of the transformer plays a role of an energy carrier, but in order to improve the coupling condition between the primary side and the secondary side of the transformer, a magnetic core with high magnetic permeability is generally required to be added on the primary side and the secondary side as a magnetic conductive medium, a typical magnetic core material is a ferrite material with high magnetic permeability, at the moment, a magnetic field generated by the coil is mainly diffused to the external environment through the magnetic core, and the receiving end of the transformer also reduces the magnetic resistance through the magnetic core, so that a magnetic flux path is shortened, and the coupling coefficient is improved.
In the above embodiment, as to the placement of the magnetic core material, as shown in fig. 6, the insulating plate 140 including the transmitting end and the magnetic core 120 including the transmitting end, in order to reduce the weight and cost of the transformer, a strip-shaped magnetic core structure is adopted instead of a whole-block magnetic core structure, and the strip-shaped magnetic cores are spliced to form the transformer. In fig. 6, the transmitting-end magnetic core 120 is composed of four magnetic cores, each of which is composed of five strip-shaped magnetic cores. In practical applications, the number of the magnetic cores and the corresponding placement positions thereof are generally determined according to the size of the selected strip-shaped magnetic core and the size of the transmitting and receiving device, and the magnetic cores at the receiving end can also be placed in the same way. For fixing, the magnetic core position can be fixed by hot melt adhesive at the boundary of the emitting end and the ground of the magnetic core 120, which is in contact with the emitting end insulating plate 140, and the contact section can be fixed by double-sided adhesive material with higher strength. In addition, in order to increase the structural strength of the device, the insulating plate can be fixed by selecting a wood plate or an epoxy plate with certain strength.
When a high-frequency current passes through a conductor, the high-frequency current tends to flow through the surface of the conductor due to the skin effect and the proximity effect, which increases the ac resistance of the line, increases the loss on the wire, and affects the system efficiency. One of the methods for reducing the skin effect is to use a plurality of strands of litz wire connected in parallel as a coil material of a transformer, the litz wire is a type of wire wound with a plurality of strands of fine wires and wrapped with wires, and the influence of the skin effect can be reduced because the diameter of the wire inside the litz wire is small. In the above embodiment, in order to further reduce the loss of the transmitting end coil 110 and the receiving end coil 210, a typical implementation method is to use a parallel connection of multiple litz wires, and the number of parallel connection turns of the litz wires is determined by the current and power level of the primary side and the secondary side of the transformer.
In the above embodiment, in order to achieve decoupling between the two coils on the secondary side of the transformer, so that the two outputs can be independently controlled to achieve coupling compensation under the condition of offset, the two coils should be placed in an overlapping manner, so that the mutual inductance of the two coils is approximately zero.
When the wireless charging device of the electric automobile works, due to the fact that the coupling coefficient between the transmitting device and the receiving device is low, a large part of a magnetic field generated by the transmitting device can be diffused into the surrounding environment, electromagnetic interference can be caused to other circuits and electronic equipment by the part of the magnetic field, and electromagnetic radiation can be generated to pedestrians passing through the automobile and people in the automobile. Therefore, a shielding device should be added to the loose magnetically coupled transformer. In the above embodiments, the shielding devices 130 and 230 are made of high conductivity aluminum plate material, and the aluminum plate is placed on the back of the device, so that the electromagnetic radiation interference of the transformer device can be effectively reduced by the counteracting magnetic field generated by the eddy current inside the aluminum plate.
Example two:
fig. 7 is a structure of a loose magnetic coupling transformer for wireless power transmission, which includes a transmitting end metal plate 130, a transmitting end insulating plate 140, a transmitting end magnetic core 120, transmitting end coils 110 and 111, a receiving end metal plate 230, a receiving end coil 210, a receiving end magnetic core 220, and a receiving end insulating plate 240. The transmitting and receiving device of the loose magnetic coupling transformer is formed by winding a plurality of litz wires in parallel. Especially, in the present embodiment, the receiving end coil 210 is uniformly wound on the upper and lower surfaces of the insulating plate, the transmitting end coils 110 and 111 are wound on one side of the insulating plate in a staggered manner, and the arrangement of the coil positions should make the two coils physically decoupled, i.e. the mutual inductance between the two coils is approximately zero. In addition, the transmitting end metal plate 130 and the receiving end metal plate 230 are made of aluminum materials to shield electromagnetic radiation; the transmitting end insulating plate 140 and the receiving end insulating plate 240 are made of plastic, wood or epoxy plate materials to perform insulating and fixing functions; the ferrite material selected by the transmitting end magnetic core 120 and the receiving end magnetic core 220 plays a role in guiding a magnetic circuit, enhances the coupling coefficient between the primary side and the secondary side of the transformer, and can play a certain shielding role.
For the circuit part of this embodiment, as shown in fig. 8, since the receiving side of the loose magnetic coupling transformer adopts a single-side wound staggered coil structure, the secondary coil is connected to one path of rectifier circuit module after passing through the receiving side impedance matching network, and the output of the rectifier circuit module is connected to the load, so as to realize power output; because the transmitting side of the loose magnetic coupling transformer adopts a spiral coil structure wound on two sides, two primary side coils are respectively connected to two inverter circuit modules 1 and 2 after passing through the transmitting side impedance matching networks 1 and 2, and the outputs of the two inverter circuit modules are connected in parallel and then connected with a power supply, so that power input is realized. The coupling compensation of the coil can be realized through the matching of the circuit structure and a loose magnetic coupling transformer, and then the high coupling coefficient can be kept under the conditions that the primary side and the secondary side of the transformer are opposite and offset.
Taking the structure of the loose magnetic coupling transformer shown in fig. 4 as an example, simulation analysis is performed by using commercial finite element simulation software ansofmaxwell 3D, and the improvement effect of the structure on the coupling coefficient under the conditions that the primary side and the secondary side are opposite and offset is specifically described.
The simulated test conditions were: the external dimension of the original secondary side transformer is 600mm x 600mm, the distance between the original secondary sides is 200mm, the coil adopts a single-turn thick lead and is provided with a Stranded winding, namely a Stranded wire winding, the coil is made of copper, the magnetic core material is ferrite material with the magnetic conductivity of 2500, an aluminum plate with the thickness of 15mm is added on the back of the primary side spiral coil to serve as a shielding material, and 100A current is applied to each coil by selecting excitation current. When the coupling coefficient of the primary side and the secondary side is researched, the current excitation value has little influence on the primary side and the secondary side, and the current excitation value is mainly related to the physical structures such as the size and the position of the coil of the primary side and the secondary side and the magnetic core.
By optimizing the width of the coil, the distance between the magnetic cores, the length of the magnetic cores and the interleaving amount of the interleaved coils in software, the approximate peak value of the primary and secondary side coupling coefficients under the existing size can be obtained. When the primary and secondary sides are aligned, the two interleaved coils of the secondary side are taken as a whole (the Group function is used in software), so that the coupling coefficient between the primary and secondary side coils can be obtained to be 0.241 by a method that the secondary side output end is connected in parallel on the direct current side under the optimized condition, and a higher coupling coefficient value under the corresponding size can be achieved.
When the primary side and the secondary side of the loose magnetic coupling transformer are relatively deviated, for a traditional circular coil, a spiral coil or a DD-type coil, when the deviation amount reaches 150 mm-200 mm, the coupling coefficient between the primary side and the secondary side is reduced to a level close to 0, and at the moment, the transformer almost loses the capacity of transmitting power because the coupling coefficient is too low.
For a traditional biplane coil, two coils are usually formed by one coil through a series connection structure, and the corresponding circuit structure is still that the primary side is an inverter module and the secondary side is a rectifier module. For the loosely magnetically coupled transformer structure and the corresponding circuit structure proposed by the present invention, taking the loosely magnetically coupled transformer structure shown in fig. 4 and the circuit structure shown in fig. 5 as examples, the two windings on the secondary side of the transformer realize decoupling between each other, i.e. the coupling coefficient k23The output of the two paths of the three-phase motor is approximate to zero, so that the two paths of the three-phase motor can realize the decoupling of control; meanwhile, under the circuit structure, by a method that the secondary output end is connected in parallel at the direct current side, the coupling coefficient of the two secondary coils as a whole and the primary coil can be expressed as follows:
therefore, the values of the corresponding coupling coefficients can be obtained as shown in the following table (wherein the X direction is along the magnetic path newly guided by the magnet, and the Y direction is perpendicular to the magnetic path) under the condition that the primary side and the secondary side have certain offset:
when the X direction is 0mm offset:
| in the X direction | Coefficient of integral coupling |
| 0mm | 0.241 |
| 100mm | 0.184 |
| 200mm | 0.161 |
| 300mm | 0.146 |
When the Y direction is 0mm offset:
| y direction | Coefficient of integral coupling |
| 0mm | 0.241 |
| 100mm | 0.226 |
| 200mm | 0.190 |
| 300mm | 0.144 |
According to the simulation model, when the X direction and the Y direction reach 300mm of offset, the coupling coefficient of the whole primary side and the secondary side can still be kept to be 0.09, and the offset of the coil reaches 1/2 of the size of the coil. It can be seen from the above table that when the primary and secondary sides of the transformer deviate from a large value, the transformer still can maintain a relatively high coupling condition, and thus has a good application prospect for a wireless power transmission system of an electric vehicle.
The embodiments described above are presented to enable a person having ordinary skill in the art to make and use the invention. It will be readily apparent to those skilled in the art that various modifications to the above-described embodiments may be made, and the generic principles defined herein may be applied to other embodiments without the use of inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications to the present invention based on the disclosure of the present invention within the protection scope of the present invention.
Claims (7)
1. A wireless power transmission loose magnetic coupling transformer device with a large offset fault tolerance range is characterized in that: the device comprises a transmitting module, a receiving module and two shielding metal plates, wherein the transmitting module and the receiving module are mutually coupled; the transmitting module is arranged on the ground surface, and the receiving module is arranged on a chassis of the vehicle body; the transmitting module and the receiving module are nested in the corresponding shielding metal plates;
the transmitting module and the receiving module respectively comprise two insulating plates, a magnetic core and a coil, the magnetic core is fixedly bonded between the two insulating plates, the coil of the receiving module is in a spiral structure by being wound along the two insulating plates in a binding manner, the coils of the transmitting module are in a single-face staggered structure by being wound on one sides of the two insulating plates respectively, the two groups of coils in the single-face staggered structure realize decoupling by adjusting relative positions, and the two groups of coils are connected in parallel by an external circuit; the coupling coefficient k of the two groups of coils of the transmitting module and the coil of the receiving module as a whole and the coupling coefficient k of the two groups of coils of the transmitting module and the coil of the receiving module respectively12、k13The following relation is satisfied:
the coils of the spiral structure are spirally distributed on two sides of the magnetic core and are uniformly distributed along the direction of the magnetic circuit;
the two groups of coils with the single-face staggered structure are distributed on the same side of the magnetic core, and the two groups of coils are arranged in a way that physical decoupling is realized between the two groups of coils, namely mutual inductance between the two groups of coils is approximately zero, and the arrangement modes of the two groups of coils are mutually overlapped.
2. The wireless power transfer loose magnetically-coupled transformer device of claim 1, wherein: the insulation board is made of bakelite boards, epoxy boards, organic glass boards or glass fiber reinforced plastic boards.
3. The wireless power transfer loose magnetically-coupled transformer device of claim 1, wherein: the magnetic core is the array concatenation of arranging for monoblock magnetic core or the thin form bar magnetic core that adopts the platyzization to form.
4. The wireless power transfer loose magnetically-coupled transformer device of claim 1, wherein: the magnetic core is made of ferrite, amorphous, microcrystal, permalloy, magnetic powder core or at least 2 of the materials.
5. The wireless power transfer loose magnetically-coupled transformer device of claim 1, wherein: the coil is formed by winding two or more strands of litz wires, copper strips or copper tubes in parallel, and the number of parallel turns is determined by the current and power grade of the primary side and the secondary side.
6. The wireless power transfer loose magnetically-coupled transformer device of claim 1, wherein: the shielding metal plate is made of copper, aluminum, silver or other metal materials with good conductive performance but no magnetic conductivity.
7. A circuit matched with the transformer device of any one of claims 1 to 6, comprising a direct current power supply, an inversion module and a rectification module, wherein the direct current side of the inversion module is connected with the direct current power supply or the output side of a preceding stage rectifier, and the alternating current side of the inversion module is connected with a coil in a transmitting module through an impedance matching network; the alternating current side of the rectification module is connected with a coil in the receiving module through an impedance matching network, and the direct current side of the rectification module is connected to a load through a direct current conversion circuit;
if the coils in the transmitting module are in a single-side staggered structure, two groups of coils are respectively connected with two inversion modules through respective impedance matching networks, and the direct current sides of the two inversion modules are connected in parallel and then connected to a direct current power supply or the output side of a preceding stage rectifier to realize power input; if the coil in the receiving module is in a spiral structure, the coil is connected with the rectifying module through the impedance matching network, and the direct current side of the rectifying module is connected to a load through the direct current conversion circuit;
if the coils in the receiving module are in a single-side staggered structure, two groups of coils are respectively connected with two rectifying modules through respective impedance matching networks, and the direct current sides of the two rectifying modules are connected in parallel and then connected to a load through a direct current conversion circuit to realize power output; if the coil in the transmitting module is of a spiral structure, the coil is connected with the inverter module through the impedance matching network, and the direct current side of the inverter module is connected to the direct current power supply or the output side of the pre-stage rectifier.
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| CN113852206A (en) * | 2021-09-26 | 2021-12-28 | 浙江大学 | Loose coupling transformer device and circuit for wireless charging of electric automobile |
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| TWI479766B (en) * | 2011-08-04 | 2015-04-01 | Fu Da Tong Technology Co Ltd | Electronic charging structure of electronic device |
| JP5885837B2 (en) * | 2012-05-21 | 2016-03-16 | 株式会社テクノバ | Contactless power transformer for moving objects |
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