CN204012949U - Radio energy transmission system based on double-layer double-direction helical coil - Google Patents

Abstract

The utility model discloses a kind of radio energy transmission system based on double-layer double-direction helical coil in wireless power transmission technical field, mainly solved radio energy transmission system closely during Energy Transfer, because the impact of frequency splitting causes the problem that system efficiency of transmission is low, on the basis of this system Shi Massachusetts Institute of Technology magnetic coupling resonance radio energy transmission system, designed a kind of transmitting coil of double-layer double-direction coiling, in the coiling in the opposite direction of the unidirectional coiling transmitting coil of original individual layer inner space, there is the inner coil of the identical number of turn and pitch of turn, coiling opposite direction due to inner coil and original coil, thereby weaken the intensity of coupling coefficient, the impact that while reducing Energy Transfer closely, frequency splitting produces system efficiency of transmission, allow radio energy transmission system in shorter distance, depart from frequency splitting region, reach Critical Coupling state, and improve the energy transmission efficiency of radio energy transmission system when frequency splitting regional work closely.

Description

Radio energy transmission system based on double-layer double-direction helical coil

Technical field

The utility model belongs to wireless power transmission technical field, relate to a kind of radio energy transmission system based on double-layer double-direction helical coil, relate in particular to a kind of by changing the project organization of transmitting coil in radio energy transmission system, with this, reduce closely Energy Transfer frequency splitting and, on the impact that efficiency of transmission was produced, improve the closely energy transmission efficiency of radio energy transmission system.

Background technology

After Ni Gula tesla proposed wireless power transmission theory before a century, wireless power transmission is just the focus that people study always.Expert is carrying out the research of wireless power transmission always both at home and abroad for many years, but development of scientific research is slow all the time, in November, 2006, the Marin Soljacic scientific research group of Massachusetts Institute Technology (MIT) proposed the theory of magnet coupled resonant type wireless electric flux transmission technology first in industry physics forum of AIP.Its principle is to utilize two magnetic coupling resonance principles with identical resonance frequency (9.9MHz), diameter 60cm, the unidirectional copper wire winding coil of individual layer successfully to light a 60W bulb from the about 2m of power supply, this technology was called as WiTricity afterwards, so far, opened up wireless power transmission technology new era at medium and long distance (transmission range is greater than coil geometries) Energy Transfer.Increasingly mature along with magnetic coupling harmonic technology, the application of wireless transmission of electricity in recent years also in being gradually penetrated into our daily life, aspects such as magnetic suspension train, implantable medical device, electric automobile and mobile device.On September 1st, 2010, standardization body--(the Wireless Power Consortium of wireless charging alliance of the first promotion wireless charging technology in the whole world, WPC) in Beijing, announce Qi wireless charging international standard to take the lead in introducing China, the compatible quality monitoring of Ministry of Information Industry's communication electromagnetism center also adds this tissue.Although in recent years wireless charging technology be in always flourish in the middle of, this technology does not really spread in smart machine, a large reason is wherein the disunity of wireless charging standard.Main San great wireless charging alliance divides the standard of taking to be separately the gesture of making rival claims as an equal on the market, but also the large man who has drawn electron trade over to one's side lends impetus and strength, Zhe Sanjia alliance is respectively the WPC of wireless charging alliance (Wireless Power Consortium), the power affairs PMA of alliance (Power Matters Alliance) and the A4WP of wireless charging alliance (Alliance for Wireless Power).

The realization of wireless power transmission has three kinds of modes both at home and abroad at present:

1. induction wireless power transmission (Electromagnetic Induction Wireless Power Transmission, EI-WPT)---be similar to separable transformer, its principle is Faradic electricity magnetic induction: when electric current flows through conductor coils, at coil, produce magnetic field around, adjacent coil produces induced electromotive force in the magnetic field changing, and then generation induced current, supply load, reaches the wireless transmission of electric energy.Because air gap in separable transformer has replaced original iron core, so the efficiency that electric energy is transferred to receiving terminal from transmitting terminal is lower, and along with the increase of primary and secondary coil distance, it is lower that efficiency can become, and is applicable to closely infinite energy transmission.

2. radio wave formula wireless power transmission (Radio-wave Wireless Power Transmission, RWPT)---its basic principle is electric energy to be converted to high frequency radio wave (as microwave) in space, transmit, receiving terminal is collected and is dispersed in the electromagnetic wave in environment, after detection and rectification, supply with DC load and use, by far field, carry out the transmission of energy.Be applicable to remote, large-scale wireless power transmission, especially suitable at energy receiving terminal than comparatively dense, be not subject to transmit under the condition of surrounding environment restriction, be to study at present many radio wave energy transmission meanss, but this kind of wireless power transmission mode is on biotic environment impact is large and efficiency is very low.

3. magnet coupled resonant type wireless delivery of electrical energy (magnetically-coupled resonant wireless power transmission, MCR-WPT)--the brand-new scheme that the Marin Soliacic of the Massachusetts Institute of Technology and group member thereof propose, its principle is to utilize two non-radiative near field magnetic between the resonance coil with identical resonance frequency to be coupled transferring energy, energy is vibration exchange back and forth between two resonance coils, reduced to a great extent the injury to human body, extended the distance of wireless power transmission, this mode efficiency of transmission is high, distance, power is large, it is the main flow direction of following wireless power transmission development.

Frequency splitting is ubiquitous phenomenon in magnetic coupling resonance and induction type wireless power transmission, and especially, when Energy Transfer closely, frequency splitting has a strong impact on the efficiency of transmission of system.According to the mode of operation of coupling coefficient size and system, the working region of radio energy transmission system can be divided into three kinds: close coupling, Critical Coupling, weak coupling region.

Research is found when radio energy transmission system is during in close coupling region, the efficiency of transmission of system obtains maximum in resonance frequency both sides, it is frequency of occurrences division, increase along with transmission range, coupling coefficient reduces, frequency splitting phenomenon fades away, when coupling coefficient reaches Critical Coupling, the efficiency of transmission of system obtains maximum at resonance frequency place, while further reducing to reach weak coupling region along with coupling coefficient, the efficiency of transmission of system reduces and sharply declines with coupling coefficient, but the transmission state of system the best is at resonance frequency place all the time, be that frequency splitting only appears at close coupling region.

In sum, the optimum Working of radio energy transmission system is Critical Coupling state, system just can obtain at resonance frequency place maximum efficiency of transmission like this, but the corresponding transmission range of Critical Coupling state is determined, especially closely during Energy Transfer, the impact of frequency splitting is more obvious, the efficiency of transmission of system not obtains maximum under resonance frequency, but obtain maximum in resonance frequency both sides, this just makes the system can not be in Critical Coupling state, for making system depart from the close coupling region that there will be frequency splitting phenomenon in shorter distance, reach Critical Coupling state, and improve system in the efficiency of transmission in close coupling region, the impact of frequency splitting while reducing Energy Transfer closely, therefore, we must find a kind of technical method to realize such scheme---and allow the wireless power transmission systems beginning in shorter distance, depart from close coupling frequency splitting region, reach Critical Coupling state, the impact of frequency splitting while reducing Energy Transfer closely, energy transmission efficiency while improving radio energy transmission system near work.

Utility model content

The purpose of this utility model is: for solving radio energy transmission system closely during Energy Transfer, because the reason of frequency splitting causes the problem that efficiency of transmission is low, propose a kind of radio energy transmission system based on double-layer double-direction helical coil.

On the basis that in this system Shi Massachusetts Institute of Technology magnetic coupling resonance radio energy transmission system, resonance coil (transmitting coil and receiving coil) individual layer check configuration designs, designed a kind of double-layer double-direction coiling helical coil as transmitting coil, be on the basis of the unidirectional coiling spiral of original individual layer transmitting coil, portion space coiling in the opposite direction within it has the inner coil of the identical number of turn and pitch of turn, then be connected to form the spiral transmitting coil of a double-layer double-direction coiling with original outer coil, coiling opposite direction due to inner coil and outer coil, thereby intensity is counted in the coupling weakening between transmitting coil and receiving coil accurately, the close coupling region of reduction system, reduce the impact that frequency splitting produces system, allow the wireless power transmission systems beginning in shorter distance, depart from close coupling frequency splitting region, reach Critical Coupling state, energy transmission efficiency while improving radio energy transmission system near work.The utility model can significantly improve the closely efficiency of Energy Transfer of radio energy transmission system simultaneously, both can meet well equipment to radio energy transmission system efficiency and in-plant requirement, can improve utilization rate of electrical again.

For realizing above-mentioned target, the technical solution adopted in the utility model is: a kind of radio energy transmission system based on double-layer double-direction helical coil, comprise a transmitter and a receiver, described transmitter comprises high frequency signal generator, impedance matching network, source coil and transmitting coil, the high-frequency signal of described high frequency signal generator output rated power; Described source coil one side is connected to high frequency signal generator by power amplifier, impedance matching network, and opposite side and described transmitting coil utilize electromagnetic induction to form a step-up transformer network; Described receiver comprises receiving coil and loading coil, and described receiving coil and loading coil utilize electromagnetic induction to form a step-down transformer network,

Described transmitting coil is the helical coil of a double-layer double-direction coiling, the helical coil of this double-layer double-direction coiling is comprised of coiling opposite direction connected inner coil and outer coil, described inner coil and outer coil have the identical number of turn and pitch of turn, and only coil radius is different.

According to radio energy transmission system of the present utility model, further, the clockwise unidirectional coiling of described outer coil, unidirectional coiling that described inner coil is counterclockwise.

According to radio energy transmission system of the present utility model, further, unidirectional coiling that described outer coil is counterclockwise, the clockwise unidirectional coiling of described inner coil.

According to radio energy transmission system of the present utility model, further, in described radio energy transmission system, between non-conterminous coil, there is no magnetic coupling, described source coil and loading coil are all single-turn circular coils, described receiving coil is the unidirectional coiling helical coil of individual layer, coiling direction is identical with transmitting coil outer coil, and described receiving coil parameters is all identical with the outer coil of transmitting coil.

According to radio energy transmission system of the present utility model, further, described receiving coil parameter and transmitting coil ectomesoderm coil parameter comprise coil radius, coil turn and coil turn distance.

According to radio energy transmission system of the present utility model, further, the electrical quantity of described source coil and loading coil is identical, and described transmitting coil and receiving coil utilize himself equivalent resistance, parasitic capacitance and self inductance composition resonant circuit under high frequency;

It is equal and constant that the spacing of the spacing of described source coil and transmitting coil, receiving coil and loading coil remains, transmitting coil and receiving coil spacing are adjustable.

According to radio energy transmission system of the present utility model, further, described source coil, transmitting coil, receiving coil and loading coil, by the copper wire winding of same size, are aligned in coaxial direction;

According to radio energy transmission system of the present utility model, further, described loading coil is connected with AC load equipment by a matching capacitance of series connection, and described matching capacitance equates with the capacitance size in impedance matching network.

According to radio energy transmission system of the present utility model, further, described loading coil is supplied with DC load equipment by a rectification circuit, or directly to AC load power supply, described rectification circuit comprises half-wave rectifying circuit, full-wave rectifying circuit and bridge rectifier.

According to radio energy transmission system of the present utility model, further, described impedance matching network is passive matching network, electric capacity and inductance, consists of.

According to radio energy transmission system of the present utility model, further, described impedance matching network is active matching network, the source follower active, passive device forms, emitter follower and buffer, consists of.

According to radio energy transmission system of the present utility model, further, described electrical quantity comprises inductance, high frequency parasitic capacitance, equivalent resistance and the internal Q of coil.

The beneficial effects of the utility model are:

1. the radio energy transmission system of the utility model based on double-layer double-direction helical coil, can make full use of the inner space of transmitting coil in radio energy transmission system, in the situation that not increasing radio energy transmission system equipment volume, reduce the closely impact of frequency splitting on system efficiency of transmission during Energy Transfer of radio energy transmission system, the energy transmission efficiency while improving radio energy transmission system near work.

2. compared with prior art, the radio energy transmission system of the utility model based on double-layer double-direction helical coil is when Energy Transfer closely, the impact that in the time of can reducing Energy Transfer closely, frequency splitting produces system efficiency of transmission, the frequency splitting region of reduction system, allow radio energy transmission system in shorter distance, depart from frequency splitting region, reach Critical Coupling state.

3. compared with prior art, the radio energy transmission system of the utility model based on double-layer double-direction helical coil is when Energy Transfer closely, can significantly improve the energy transmission efficiency of radio energy transmission system when frequency splitting regional work closely, further solve system efficiency of transmission and be subject to the closely problem of frequency splitting restriction, improved the utilization ratio of electric energy.

4. the radio energy transmission system of the utility model based on double-layer double-direction helical coil is the same with the shared spatial volume of existing wireless energy transfer system, in the occasion of the higher wireless transmission of electricity of environmental requirement to external world, double-layer double-direction helical coil can be utilized space resources more fully.

Accompanying drawing explanation

Fig. 1 is magnetic coupling resonance radio energy transmission system frequency splitting phenomenon exemplary plot;

Fig. 2 is unidirectional and double-layer double-direction coiling schematic diagram, wherein Fig. 2 (a) of transmitting coil individual layer in radio energy transmission system: the unidirectional coiling schematic diagram of transmitting coil individual layer, Fig. 2 (b): transmitting coil double-layer double-direction coiling schematic diagram;

Fig. 3 is the radio energy transmission system model schematic diagram based on individual layer one-way spiral coil;

Fig. 4 is the equivalent-circuit model figure of the radio energy transmission system based on individual layer one-way spiral coil;

Fig. 5 is the transmitting coil unidirectional coiling of individual layer and double-layer double-direction coiling and receiving coil coupling coefficient comparison diagram respectively;

Fig. 6 is the structure parameter optimizing simulation result figure to inner coil in transmitting coil, wherein Fig. 6 (a): efficiency of transmission η is with internal diameter R _ichange curve, Fig. 6 (b): efficiency of transmission η is with number of turn N change curve, and Fig. 6 (c): efficiency of transmission η is with the pitch of turn p change curve of inner coil;

Fig. 7 is the radio energy transmission system of the utility model based on double-layer double-direction helical coil and the efficiency of transmission simulation comparison figure of existing magnetic coupling harmonic technology, Fig. 7 (a) wherein: existing magnetic coupling harmonic technology radio energy transmission system efficiency analogous diagram, Fig. 7 (b): the radio energy transmission system efficiency analogous diagram based on double-layer double-direction helical coil;

Fig. 8 is the radio energy transmission system example pictorial diagram of the utility model based on double-layer double-direction helical coil;

Fig. 9 is the radio energy transmission system of the utility model based on double-layer double-direction helical coil and the efficiency of transmission experiment comparison diagram of existing magnetic coupling harmonic technology.

Embodiment

In order to make content and the advantage of technical solutions of the utility model more cheer and bright, below in conjunction with accompanying drawing, the radio energy transmission system to the utility model based on double-layer double-direction helical coil is described in further detail.Should be emphasized that, following explanation is only exemplary, rather than in order to limit the utility model scope and application thereof.

Below in conjunction with accompanying drawing, describe the implementation procedure of the radio energy transmission system of the utility model based on double-layer double-direction helical coil in detail.

Fig. 1 is magnetic coupling resonance radio energy transmission system frequency splitting phenomenon exemplary plot.

As shown in Figure 1, frequency splitting phenomenon is very common in magnetic coupling resonance and induction type wireless power transmission, frequency splitting is mainly while transmitting electricity due near radio, between the transmitting coil of the unidirectional coiling of individual layer and receiving coil, coupling coefficient is excessive, has occurred that overcoupling situation causes the phenomenon of the optimum resonance point drift of transmission system.Magnetic coupling resonance wireless power transmission systems is the result of overcoupling (coupling coefficient the is excessive) effect between equivalent load and resonance coil (transmitting coil and receiving coil) in the main cause of closely frequency of occurrences division, cause the mode of operation of energy transmission system to change, and frequency splitting phenomenon occur over just overcoupling region.

In four traditional coil radio energy transmission systems, mainly by source coil, transmitting coil, receiving coil and loading coil, formed, wherein transmitting coil and receiving coil are all the unidirectional coiling helical coils of individual layer, this loop construction design has caused radio energy transmission system when Energy Transfer closely, to there will be the phenomenon of frequency splitting, makes system at driving source frequency (f ₀=10.6MHz) locate efficiency of transmission low, and the maximum of going in its both sides, in Fig. 1, d is system transmission range.

Fig. 2 is unidirectional and double-layer double-direction coiling schematic diagram, wherein Fig. 2 (a) of transmitting coil individual layer in radio energy transmission system: the unidirectional coiling schematic diagram of transmitting coil individual layer, Fig. 2 (b): transmitting coil double-layer double-direction coiling schematic diagram;

As shown in Figure 2, in four traditional loop construction radio energy transmission systems, transmitting coil and receiving coil are the unidirectional coilings of individual layer, and coiling schematic diagram is as shown in Fig. 2 (a).For improving the in-plant efficiency of transmission of radio energy transmission system, reduce the impact of frequency splitting, in the radio energy transmission system of the utility model based on double-layer double-direction helical coil, by having designed a kind of double-layer double-direction coiling helical coil as the transmitting coil of radio energy transmission system, by inside and outside two-layer coil, be formed by connecting, described outer coil is according to the suitable unidirectional coiling of (contrary) hour hands, described inner coil is the contrary unidirectional coiling of (suitable) hour hands, it is ectonexine coil winding opposite direction, and there is the identical number of turn and pitch of turn, only the outer R of inner coil radius _iwith outer coil radius R ₀difference, coiling schematic diagram is as shown in Fig. 2 (b), and Fig. 2 (b) is transmitting coil double-layer double-direction coiling schematic diagram.

Fig. 3 is the radio energy transmission system model schematic diagram based on individual layer one-way spiral coil.

As shown in Figure 3, the radio energy transmission system based on individual layer one-way spiral coil comprises high frequency signal generator, impedance matching network, power amplifier, source coil, transmitting coil, receiving coil, loading coil and load equipment.

High frequency signal generator is sent high-frequency signal pulse, after impedance matching network and power amplifier, energy signal is passed to source coil, the energy transmitting coil of described system utilizes electromagnetic induction to obtain from source coil the high-frequency oscillation signal that high frequency signal generator is sent, then sends out with the form of non-radiative near field electromagnetic ripple.The energy receiving coil of described system receives the high-frequency oscillation signal that transmitting coil transmits, then by electromagnetic induction by Power supply loading coil, loading coil is supplied with DC load equipment or circuit by a rectification circuit, or directly to AC load, powers.Source coil and loading coil are all single-turn circular coils, and transmitting coil and receiving coil are the unidirectional coiling helical coils of individual layer, and coiling direction is identical, and its every (as coil radius, the number of turn and pitch of turn etc.) are all identical with transmitting coil.The distance of transmitting coil and receiving coil is the transmission range of described system.

All coils is by copper wire winding, be aligned in coaxial direction, along with transmission range is ascending, increase gradually, the maximum of points of system efficiency of transmission starts to have 2, it is frequency of occurrences separating phenomenon, then merge into gradually 1, working state of system is by being strongly coupled to Critical Coupling, then to the change procedure of weak coupling.

Fig. 4 is the equivalent-circuit model figure of the radio energy transmission system based on individual layer one-way spiral coil.

As shown in Figure 4, the equivalent-circuit model of the radio energy transmission system based on individual layer one-way spiral coil has four wire loops: source coil loop, transmitting coil loop, receiving coil loop, loading coil loop.L ₁, L ₂, L ₃, L ₄be respectively the inductance in source coil, transmitting coil, receiving coil and loading coil loop, R ₁, R ₂, R ₃, R ₄be respectively source coil, transmitting coil, receiving coil and the loading coil loop equivalent resistance under high frequency, C ₁the parasitic capacitance of source coil loop under high frequency and the matching capacitance sum in impedance matching network, C ₂and C ₃respectively transmitting coil and the receiving coil loop parasitic capacitance under high frequency, C ₄the parasitic capacitance of loading coil loop under high frequency and the matching capacitance sum of series connection with it, V _sthe output voltage of high frequency signal generator, V _lload voltage, R _s, R _lrespectively equivalent internal resistance and the load resistance of high frequency signal generator; k ₁₂the coupling coefficient between source coil and transmitting coil, k ₂₃the coupling coefficient between transmitting coil and receiving coil, k ₃₄be the coupling coefficient between receiving coil and loading coil, for simplifying, calculate, can, by adjusting the relative position between coil, ignore the cross-couplings between non-conterminous coil.Situation while considering power-supply system and load circuit real work, conventionally R ₁< < R _s, R ₄< < R _lso, have R ₁+ R _s≈ R _s, R4+R _l≈ R _l.

Equivalent-circuit model analytical procedure to the radio energy transmission system based on individual layer one-way spiral coil is as follows:

1. the equivalent electric circuit of pair described system is analyzed, and obtains equation as described below:

$\left[\begin{array}{c}{V}_S\\ 0\\ 0\\ 0\end{array}\right]=\left[\begin{array}{cccc}{R}_S+R_1+\mathrm{j\&omega;}(L_1-\frac{1}{C_1})& \mathrm{j\&omega;}{k}_{12}\sqrt{L_1{L}_{12}}& 0& 0\\ \mathrm{j\&omega;}{k}_{12}\sqrt{L_1{L}_2}& R_2+\mathrm{j\&omega;}(L_2-\frac{1}{C_2})& \mathrm{j\&omega;}{k}_{23}\sqrt{L_2{L}_3}& \stackrel{\&CenterDot;}{0}\\ 0& \mathrm{j\&omega;}{k}_{23}\sqrt{L_2{L}_3}& R_3+\mathrm{j\&omega;}(L_3-\frac{1}{C_3})& \mathrm{j\&omega;}{k}_{34}\sqrt{L_3{L}_4}\\ 0& 0& \mathrm{j\&omega;}{k}_{34}\sqrt{L_3{L}_4}& R_L+R_4+\mathrm{j\&omega;}(L_4-\frac{1}{C_4})\end{array}\right]\left[\begin{array}{c}{I}_1\\ I_2\\ I_3\\ I_4\end{array}\right]$

I in above-mentioned equation ₁, I ₂, I ₃, I ₄respectively source coil loop current, transmitting coil loop current, receiving coil loop electric current, loading coil loop current.

2. system works is at resonance frequency (ω=ω ₀) time, determinant in described step 1 is solved to I ₁, I ₄, can obtain the input and output voltage ratio of system as described below:

k wherein ₁₂the coupling coefficient between source coil and transmitting coil, k ₃₄the coupling coefficient between receiving coil and loading coil, k ₂₃the coupling coefficient between transmitting coil and receiving coil, Q ₁, Q ₂, Q ₃respectively the quality factor of source coil, transmitting coil and receiving coil.

3. impedance matching, i.e. input impedance Z _im=R _stime, signal source has peak power output, and the efficiency of transmission η expression formula of system is as follows: $\mathrm{\&eta;}=\frac{V_L^2}{R_L}/\frac{V_s^2}{4R_s}={\left|S_{21}\right|}^2={\left\{\frac{2k_{12}^2{k}_{23}{Q}_1{Q}_2{Q}_3}{1+k_{12}^2{Q}_1{Q}_2+k_{23}^2{Q}_2{Q}_3}\right\}}^2,$ Be $S_{21}=\frac{2k_{12}^2{k}_{23}{Q}_1{Q}_2{Q}_3}{1+k_{12}^2{Q}_1{Q}_2+k_{23}^2{Q}_2{Q}_3},$ S ₂₁it is the transformation parameter of described radio energy transmission system.

4. described in, in system, the quality factor of each coil are all the known quantities that can indirectly measure: ω wherein ₀it is the angular frequency of extrinsic motivated source signal that high frequency signal generator produces.For the radio energy transmission system based on individual layer one-way spiral coil, its efficiency of transmission not under resonance frequency always in maximum, but maximum at Critical Coupling place, therefore S in described step 3 ₂₁to k ₂₃ask local derviation, order the Critical Coupling that is easy to get relational expression:

Above formula is described system works when Critical Coupling state is obtained maximum transmitted efficiency, the coupling coefficient k of transmitting coil and receiving coil ₂₃satisfied relational expression.Spacing d due to source coil and transmitting coil ₁₂remain constant, and by coupling coefficient and coil-span relational expression: known, k ₁₂constant.K in formula ₁₂the coupling coefficient between source coil and transmitting coil, r ₁, r ₂respectively the radius of source coil and transmitting coil, d ₁₂it is the spacing of source coil and transmitting coil.

Known in sum, due to k ₁₂constant, therefore by Critical Coupling relational expression known, k ₂₃also be constant, by formula known, k now ₂₃corresponding apart from d ₂₃be Critical Coupling distance.K in formula ₂₃the coupling coefficient between transmitting coil and receiving coil, r ₂, r ₃respectively the radius of transmitting coil and receiving coil, d ₂₃it is the spacing of transmitting coil and receiving coil.

When system short range transmission energy, if transmission range d < is d ₂₃, by known, coupling coefficient k ₂₃to become large, cause immediately Critical Coupling relational expression unbalance, system can enter overcoupling region, frequency of occurrences separating phenomenon, and efficiency of transmission declines.The radio energy transmission system based on double-layer double-direction helical coil the utility model proposes is that the self structure by coil balances out part because of the k that reduces to cause of transmission range ₂₃recruitment, thereby the in-plant energy transmission efficiency of raising system, and the impact of frequency splitting while suppressing short range transmission.

Fig. 5 is the transmitting coil unidirectional coiling of individual layer and double-layer double-direction coiling and receiving coil coupling coefficient comparison diagram respectively.

As shown in Figure 5, compare with the transmitting coil of the unidirectional coiling of individual layer, the double-layer double-direction coiling transmitting coil structure that the radio energy transmission system of the utility model based on double-layer double-direction helical coil adopts, because the inner coil of oppositely coiling can be offset the coupling coefficient of part outer coil and receiving coil, the coupling coefficient intensity of transmitting coil and receiving coil is declined, thereby the overcoupling effect of attenuation systems, the impact of frequency splitting on efficiency of transmission while reducing closely Energy Transfer.

Fig. 6 is the structure parameter optimizing simulation result figure to inner coil in transmitting coil, wherein Fig. 6 (a): efficiency of transmission η is with internal diameter R _ichange curve, Fig. 6 (b): efficiency of transmission η is with number of turn N change curve, and Fig. 6 (c): efficiency of transmission η is with the pitch of turn p change curve of inner coil.

In three-D high frequency Electromagnetic Simulation software HFSS, create the radio energy transmission system model based on double-layer double-direction coil, it is basis, the i.e. radius R of resonance coil (transmitting and receiving coil) that the unidirectional magnetic coupling of individual layer resonance wireless power transmission systems is take in the foundation of coil simulation model ₀=30cm, pitch of turn p ₀=4cm, number of turn n=5.25, source coil and loading coil be single turn and radius r=25cm, all copper cash radius a=3mm, the resonance frequency of resonance coil is 10.6MHz, driving source frequency setting is f ₀=10.6MHz.Due to the symmetry of this wireless power transmission systems, therefore next the Parameters Optimal Design of coil replaces transmitting coil in said system to study with double-layer double-direction helical coil, the structural parameters to inner coil---internal diameter R respectively _i, number of turn N and pitch of turn p be optimized.

As shown in Fig. 6 (a), set transmission range d=200mm, with identical copper cash coiling inner coil in transmitting coil, pitch of turn p=4cm, the number of turn N=5.25 of inner coil, only change the internal diameter R of inner coil _i, simulation result shows that the efficiency of transmission η of described system is with internal diameter R _ireduce and reduce gradually, and there will be the skew of system maximal efficiency transfer point.

As shown in Fig. 6 (b), set transmission range d=200mm, with identical copper cash coiling inner coil in transmitting coil, the internal diameter R of inner coil _i=290mm, pitch of turn p=4cm, only change the number of turn N of inner coil, and simulation result shows as inner coil number of turn N=n=5.25, and when identical with the outer coil number of turn, the efficiency of transmission η of described system is in driving source frequency f ₀maximum during=10.6MHz.

As shown in Fig. 6 (c), set transmission range d=200mm, with identical copper cash coiling inner coil in transmitting coil, the internal diameter R of inner coil _i=290mm, number of turn N=5.25, only change the pitch of turn p of inner coil, and simulation result shows the pitch of turn p=p when inner coil ₀=4cm, when identical with the pitch of turn of outer coil, the efficiency of transmission η of described system is in driving source frequency f ₀maximum during=10.6MHz.

Fig. 7 is the radio energy transmission system of the utility model based on double-layer double-direction helical coil and the efficiency of transmission simulation comparison figure of existing magnetic coupling harmonic technology, Fig. 7 (a) wherein: existing magnetic coupling harmonic technology radio energy transmission system efficiency analogous diagram, Fig. 7 (b): the radio energy transmission system efficiency analogous diagram based on double-layer double-direction helical coil.

On the basis of above-mentioned double-layer double-direction coiling helical coil analysis of optimizing design, in the radio energy transmission system of the utility model based on double-layer double-direction helical coil, the outer coil of transmitting coil and the radius of inner coil are respectively R ₀=30cm, R _i=250mm, pitch of turn p=p ₀=2cm, number of turn N=n=8, set transmission range d=200mm.

As shown in Fig. 7 (a), when radio energy transmission system transmitting coil is the unidirectional coiling of individual layer, be that its structure is as shown in Fig. 2 (a), described radio energy transmission system is carried out to emulation, simulation result is as shown in Fig. 7 (a), variation simulation curve from system efficiency of transmission with transmission range: when the transmission range of described system is less than 400mm, have frequency splitting phenomenon to occur; From transmission range is more than or equal to 400mm, frequency splitting phenomenon fades away, and hence one can see that, and the Critical Coupling distance of the described radio energy transmission system being comprised of the unidirectional coiling transmitting coil of individual layer is 400mm.

As shown in Fig. 7 (b), in radio energy transmission system at the utility model based on double-layer double-direction helical coil, be that its transmitting coil adopts method coiling as shown in Fig. 2 (b), described radio energy transmission system is carried out to emulation, simulation result is as shown in Fig. 7 (b), variation simulation curve from system efficiency of transmission with transmission range, frequency splitting phenomenon is that 250mm place starts to disappear in transmission range, be that the unidirectional coiling of individual layer is compared with radio energy transmission system transmitting coil, frequency splitting region dwindles nearly 40%, near radio energy transmission efficiency significantly improves, as at a distance of 300mm, in frequency f ₀during=10.6MHz, efficiency of transmission η brings up to 90% by 70%.

Fig. 8 is the radio energy transmission system example pictorial diagram of the utility model based on double-layer double-direction helical coil.

As shown in Figure 8, the present embodiment is that operating frequency is at f ₀the radio energy transmission system implementation based on double-layer double-direction helical coil of=10.6MHz, the copper conductor coiling that all coils is is all 3mm by section radius forms, and is aligned in coaxial direction.What in experiment, use is that model is the high frequency signal generator of HPE4431B, peak power output 10W, frequency range 250KHz--2.0GHz, its internal resistance R _s=50 ohm, output signal accesses source coil after impedance matching, power amplifier.Spectrum analyzer is used for resolving transmitting terminal and receiving end signal, electric capacity and the inductance of capacitor and inductor tester measuring coil, and loading coil is connected to the standard termination resistance of 50 Ω, by oscilloscope, observes by voltage waveform on standard termination resistance.In described system, transmitting coil is the helical coil of a double-layer double-direction coiling, by inside and outside two-layer coil, is formed by connecting; Described outer coil is according to the suitable unidirectional coiling of (contrary) hour hands, and described inner coil is the contrary unidirectional coiling of (suitable) hour hands, and ectonexine coil winding-direction is contrary, and has the identical number of turn and pitch of turn, and only inner-outer coil radius is different.Receiving coil is the unidirectional coiling of individual layer, and coiling direction is identical with the outer coil of transmitting coil, and its parameters (as coil radius, the number of turn and pitch of turn etc.) is all identical with the outer coil of transmitting coil.The distance of transmitting coil and receiving coil is the transmission range of described system.

The choosing of the present embodiment coil parameter considered the feasibility that coil is made, and tested respectively the efficiency of transmission of the magnet coupled resonant type wireless transmission system of double-layer double-direction helical coil radio energy transmission system and individual layer one-way spiral coil when transmission range d=200mm, 300mm.Because the outer coil parameter of transmitting coil in this system is identical with receiving coil, therefore the inner coil in transmitting coil in the radio energy transmission system based on double-layer double-direction helical coil is as mentioned above removed, transmitting coil after dismounting inner coil is identical with the resonance frequency of receiving coil, be the existing magnet coupled resonant type wireless electric energy transmission system device based on individual layer one-way spiral coil, keep other parameters of original system constant, carry out the magnet coupled resonant type wireless electric energy transmission system experimental verification based on individual layer one-way spiral coil.

The Major Systems parameter configuration of the radio energy transmission system of the present embodiment based on double-layer double-direction helical coil is as follows: system works frequency f ₀=10.6MHz, load resistance R _l=50; Source coil radius r ₁=25cm, number of turn N ₁=1; Transmitting coil external diameter R _o=30cm, internal diameter R _i=25cm, outer coil pitch of turn p ₀=2cm, inner coil pitch of turn p=2cm, ectonexine turn number N=n=8; Receiving coil radius R _o=30cm, pitch of turn p ₀=2cm, number of turn N=8; Loading coil radius r ₂=25cm, number of turn N ₂=1.

Fig. 9 is the radio energy transmission system of the utility model based on double-layer double-direction helical coil and the efficiency of transmission experiment comparison diagram of existing magnetic coupling harmonic technology.

In existing magnetic coupling resonance wireless power transmission technology, transmitting coil adopts the coiling of individual layer one-way spiral, in the radio energy transmission system of the utility model based on double-layer double-direction helical coil, transmitting coil adopts double-layer double-direction helically coiling, reverse coiling connected inner coil and outer coil, consists of.

As shown in Figure 9, when radio energy transmission system is during at Energy Transfer closely, transmission range d=200mm, at operating frequency f ₀=10.6MHz place, the system efficiency of transmission that existing magnetic coupling harmonic technology is corresponding is only 48%, as shown in smooth dotted line in Fig. 9.And the corresponding efficiency of transmission of the radio energy transmission system of the utility model based on double-layer double-direction helical coil is 88%, as shown in smooth solid line in Fig. 9.Compare with existing magnetic coupling harmonic technology, the utility model efficiency of transmission improves 40%.

Transmission range d=300mm, at operating frequency f ₀=10.6MHz place, the system efficiency of transmission that existing magnetic coupling harmonic technology is corresponding is 68%, as added in Fig. 9 as shown in star dotted line.And the corresponding efficiency of transmission of the radio energy transmission system of the utility model based on double-layer double-direction helical coil is 92%, as added in Fig. 9 as shown in star solid line.Compare with existing magnetic coupling harmonic technology, the utility model efficiency of transmission improves 24%.

The foregoing is only preferably execution mode of the utility model; but protection range of the present utility model is not limited to this; in every case in the technical scope that those of ordinary skill in the art disclose at the utility model; the equivalence of doing is modified or conversion, within all should being encompassed in protection range of the present utility model.

Claims (10)

1. the radio energy transmission system based on double-layer double-direction helical coil, comprise a transmitter and a receiver, described transmitter comprises high frequency signal generator, impedance matching network, power amplifier, source coil and transmitting coil, the high-frequency signal of described high frequency signal generator output rated power; One side of described source coil is connected to high frequency signal generator by impedance matching network, and opposite side and described transmitting coil utilize electromagnetic induction to form a step-up transformer network; Described receiver comprises receiving coil and loading coil, and described receiving coil and loading coil utilize electromagnetic induction to form a step-down transformer network, it is characterized in that:

Described transmitting coil is the helical coil of a double-layer double-direction coiling, the helical coil of this double-layer double-direction coiling is comprised of coiling opposite direction connected inner coil and outer coil, described inner coil and outer coil have the identical number of turn and pitch of turn, and only coil radius is different.

2. a kind of radio energy transmission system based on double-layer double-direction helical coil according to claim 1, is characterized in that the clockwise unidirectional coiling of described outer coil, unidirectional coiling that described inner coil is counterclockwise.

3. a kind of radio energy transmission system based on double-layer double-direction helical coil according to claim 1, is characterized in that unidirectional coiling that described outer coil is counterclockwise, the clockwise unidirectional coiling of described inner coil.

4. the radio energy transmission system based on double-layer double-direction helical coil according to claim 1, it is characterized in that, in described radio energy transmission system, between non-conterminous coil, there is no magnetic coupling, described source coil and loading coil are all single-turn circular coils, described receiving coil is unidirectional coiling helical coil, coiling direction is identical with transmitting coil ectomesoderm coil, and described receiving coil parameter is all identical with transmitting coil ectomesoderm coil parameter.

5. the radio energy transmission system based on double-layer double-direction helical coil according to claim 4, is characterized in that, described receiving coil parameter and transmitting coil ectomesoderm coil parameter comprise coil radius, coil turn and coil turn distance.

6. a kind of radio energy transmission system based on double-layer double-direction helical coil according to claim 1, it is characterized in that, the electrical quantity of described source coil and loading coil is identical, and described transmitting coil and receiving coil utilize himself equivalent resistance, parasitic capacitance and self inductance composition oscillating circuit under high frequency;

It is equal and constant that the spacing of the spacing of described source coil and transmitting coil, receiving coil and loading coil remains, transmitting coil and receiving coil spacing are adjustable.

7. a kind of radio energy transmission system based on double-layer double-direction helical coil according to claim 6, is characterized in that, described electrical quantity comprises inductance, high frequency parasitic capacitance, equivalent resistance and the internal Q of coil.

8. a kind of radio energy transmission system based on double-layer double-direction helical coil according to claim 1, is characterized in that, described source coil, transmitting coil, receiving coil and loading coil, by the copper wire winding of same size, are aligned in coaxial direction.

9. a kind of radio energy transmission system based on double-layer double-direction helical coil according to claim 1, it is characterized in that, described loading coil is connected with AC load equipment by a matching capacitance of series connection, and described matching capacitance equates with the capacitance size in impedance matching network.

10. a kind of radio energy transmission system based on double-layer double-direction helical coil according to claim 1, it is characterized in that, described loading coil is supplied with DC load equipment by a rectification circuit, or directly to AC load power supply, described rectification circuit comprises half-wave rectifying circuit, full-wave rectifying circuit and bridge rectifier.