CN204721105U - Insert the asymmetric wireless power transmission systems of repeating coil - Google Patents

Abstract

The utility model discloses a kind of asymmetric wireless power transmission systems inserting repeating coil in magnetic coupling resonant radio energy transmission technique field, repeating coil isoplanar coaxial with transmitting coil, mainly solve the wireless power transmission systems problem that efficiency of transmission is lower under medium and long distance that transmitting coil size is greater than receiving coil size, this utility model is by inserting isoplanar repeating coil coaxial with transmitting coil in systems in which, enhance the coefficient of mutual inductance between adjacent windings, improve the degree of coupling between coil, and then improve the efficiency of transmission of system, and repeating coil saves bulk with the coaxial isoplanar structure of transmitting coil, more be conducive to wireless power transmission systems application in practice.

Description

Insert the asymmetric wireless power transmission systems of repeating coil

Technical field

The utility model belongs to magnetic coupling resonant radio energy transmission technique field, relate to a kind of asymmetric wireless power transmission systems inserting repeating coil, particularly relate to a kind of new design structure being greater than repeating coil in the asymmetric radio energy transmission system of receiving coil size in transmitting coil size, repeating coil isoplanar coaxial with transmitting coil, save bulk with this, improve the efficiency of transmission of radio energy transmission system.

Background technology

Along with the development of science and technology, wireless power transmission technology has obtained the concern of increasing people, especially in November, 2006, the Marin Soliacic of Massachusetts Institute Technology and research group thereof are in industry physics forum of AIP, utilize magnetic coupling resonance principle, successfully lighted a distance power supply and be about 2m 60W bulb far away, this technology was called as WiTricity afterwards, and it has evoked the research boom of people to wireless power transmission systems.Along with going deep into of studying magnetic coupling harmonic technology, various countries experts and scholars develop powerful wireless electric energy transmission device in succession, the aspects such as such as magnetic suspension train, anury household electrical appliances, implantable medical device, electric automobile and mobile device.

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

1. radio waves wireless power transmission (Radio-wave Wireless Power Transmission, RWPT)---its general principle utilizes radio wave (as microwave) to replace wire, realizes the transmission of electric energy.Can realize high-power and remote delivery of electrical energy, be the radio wave energy transmission means that research is many at present, but its transmission attenuation is comparatively serious, the efficiency of transmitting energy is not high, and larger on bioenvironmental impact.

2. induction wireless power transmission (Electromagnetic Induction Wireless Power Transmission, EI-WPT)---its general principle utilizes electromagnetic induction principle that electric energy is transferred to secondary winding from primary and secondary winding, 2 winding close-coupled, efficiency of transmission is very high, but the distance of transmission is shorter, can only be limited in millimeter or centimetre scope, meanwhile, 2 coil winding arrangement dimensional requirements are accurate.

3. magnet coupled resonant type wireless delivery of electrical energy (magnetically-coupled resonant wireless power transmission, MCR-WPT)---its principle is by transmitting coil and receiving coil furnishing resonator system, when the frequency of oscillation of transmitting coil will produce resonance with receiving coil natural frequency phase simultaneity factor, energy is only vibrated alternately having between the transmitting coil of identical resonance frequency and receiving coil, thus carry out the transmission of energy, and do not have the mutual of energy with other non-resonant objects.It compensate for induction wireless power transmission technical transmission apart from short defect, transmission range is brought up to meter level scope, also overcomes the deficiency that microwave type wireless power transmission mode efficiency of transmission is low, substantially increases the efficiency of transmission of system.

Efficiency of transmission is one of main performance index of magnetic coupling resonant radio energy transmission system, the efficiency of transmission of the coefficient of mutual inductance meeting influential system between coil.

Research finds that efficiency of transmission that transmitting coil size is greater than the wireless power transmission systems of receiving coil size is less than the wireless power transmission systems of transmitting and receiving device full symmetric under kindred circumstances, its transmission range also can be affected, but in the radio energy transmission system of reality, transmitting coil and receiving coil are difficult to reach symmetrical completely, increasing repeating coil can resolution system efficiency of transmission is low effectively problem, which increase the coefficient of mutual inductance between coil, degree of coupling between coil is strengthened, and then system is transmitted with higher efficiency.

In sum, radio energy transmission system is in the application of reality, emitter and receiving system are difficult to reach symmetrical completely, such as: when wireless charging is carried out to mobile devices such as mobile phones, the size of transmitting coil is greater than the size of receiving coil, and in this asymmetric radio energy transmission system, efficiency of transmission will decline to some extent, and along with the increase of transmission range, the efficiency of transmission of system can sharply decline, universal and the application of wireless power transmission systems can be restricted, for this reason, we must find a kind of technical pattern to realize such scheme---and the wireless power transmission systems allowing transmitting coil size be greater than receiving coil size realizes higher efficiency transmission under medium and long distance.

Utility model content

When the purpose of this utility model is that the wireless power transmission systems being greater than receiving coil size for transmitting coil size carries out Energy Transfer, coefficient of mutual inductance is less and cause the problem that system transfers efficiency is lower, proposes a kind of asymmetric wireless power transmission systems inserting repeating coil.This system is greater than in the magnetic coupling resonance wireless power transmission systems of receiving coil size at transmitting coil, insert isoplanar repeating coil coaxial with transmitting coil, the coefficient of mutual inductance of transmitting terminal and receiving terminal is strengthened, and then improve the efficiency of transmission of system, simultaneously, the utility model can also save bulk, and the volume reducing system is more conducive to wireless power transmission application in practice.

For realizing above-mentioned target, the technical solution adopted in the utility model is: the asymmetric wireless power transmission systems inserting repeating coil, and described wireless power transmission systems comprises an emitter, a relay and a receiving system; Described emitter comprises high frequency signal generator, impedance matching network, power amplifier and transmitting coil, the side of described transmitting coil is connected to high frequency signal generator by impedance matching network, opposite side and receiving coil produce resonance, and energy is vibrated in the form of an electromagnetic wave between two coils; Described relay comprises a repeating coil, and described repeating coil is arranged with the coaxial isoplanar of transmitting coil, has the identical number of turn and pitch of turn, and described repeating coil is different from transmitting coil radius; Described receiving system comprises receiving coil, load equipment and power meter, the radius of the radius ratio transmitting coil of described receiving coil is little, its number of turn is identical with transmitting coil with pitch of turn, and described receiving coil side is connected to load equipment, and opposite side and transmitting coil produce resonance; Described transmitting coil, repeating coil, receiving coil are on same level axle, and the distance of transmitting coil and receiving coil is 1m.

According to transmission system described in the utility model, described impedance matching network is active matching network, and the source follower be made up of active, passive device, emitter follower and buffer are formed;

According to transmission system described in the utility model, described impedance matching network is passive matching network, is made up of inductance and electric capacity.

According to transmission system described in the utility model, described repeating coil is wound on transmitting coil skin.

According to transmission system described in the utility model, described receiving coil is multiturn helical coil, a matching capacitance of connecting, and directly connects AC load equipment; Or described receiving coil is by a rectification circuit supply DC load equipment or circuit; Described rectification circuit comprises halfwave rectifier, full-wave rectification and bridge rectifier.

According to transmission system described in the utility model, described transmitting coil, repeating coil and receiving coil utilize himself in high frequency equivalent resistance, parasitic capacitance, matching capacitance and own inductance composition oscillating circuit, transmitting coil, repeating coil and receiving coil have identical resonance frequency.

According to transmission system described in the utility model, described transmitting coil, repeating coil and receiving coil are multiturn coil.

The beneficial effects of the utility model are:

1. the asymmetric wireless power transmission systems of the insertion repeating coil that the utility model proposes, between the magnetic coupling resonance wireless power transmission systems that transmitting coil can be made to be greater than receiving coil size, the coefficient of mutual inductance of adjacent windings strengthens, thus system is transmitted with higher efficiency.

2. compared with prior art, the asymmetric wireless power transmission systems of the insertion repeating coil that the utility model proposes is when medium and long distance is transmitted, can make to keep higher mutual inductance between adjacent windings, and then efficiency of transmission is had improve very significantly, solve the problem that system transfers efficiency is subject to transmitting coil and receiving coil size constrained further, improve the utilization ratio of electric energy in system.

Accompanying drawing explanation

Fig. 1 is the structure chart of asymmetric magnet coupled resonant type wireless transmission system.

Fig. 2 is repeating coil of the present utility model isoplanar schematic diagram coaxial with transmitting coil.

Fig. 3 is the equivalent-circuit model figure of the asymmetric wireless power transmission systems of insertion repeating coil of the present utility model.

Fig. 4 is the Changing Pattern analogous diagram of asymmetric wireless power transmission systems efficiency of transmission with frequency of insertion repeating coil of the present utility model.

Fig. 5 is the Changing Pattern lab diagram of asymmetric wireless power transmission systems efficiency of transmission with frequency of insertion repeating coil of the present utility model.

Fig. 6 is the simulation and experiment comparison diagram of asymmetric wireless power transmission systems efficiency of transmission with the Changing Pattern of frequency of insertion repeating coil of the present utility model.

Embodiment

In order to the content and advantage that make technical solutions of the utility model clearly understand, below in conjunction with the drawings and specific embodiments, asymmetric wireless power transmission systems the utility model being inserted to repeating coil is described in further detail.It is emphasized that following explanation is only exemplary, instead of in order to limit scope of the present utility model and application thereof.

Wireless power transmission systems described in the utility model comprises an emitter, a relay and a receiving system.Described emitter comprises high frequency signal generator, impedance matching network, power amplifier and transmitting coil, the side of described transmitting coil is connected to high frequency signal generator by impedance matching network, opposite side and receiving coil produce resonance, and energy is vibrated in the form of an electromagnetic wave between two coils; Described relay comprises a repeating coil, and described repeating coil is arranged with the coaxial isoplanar of transmitting coil, has the identical number of turn and pitch of turn, and radius is different; Described receiving system comprises receiving coil, load equipment and power meter, the radius of the radius ratio transmitting coil of described receiving coil is little, its number of turn is identical with transmitting coil with parameters such as pitchs of turn, and described receiving coil side is connected to load equipment, and opposite side and transmitting coil produce resonance; Described transmitting coil, repeating coil, receiving coil are on same level axle.

Described transmitting coil, repeating coil and receiving coil utilize himself in high frequency equivalent resistance, parasitic capacitance, matching capacitance and own inductance composition oscillating circuit, transmitting coil, repeating coil and receiving coil have identical resonance frequency.The center of described transmitting coil, receiving coil and repeating coil is on same level axle, when distance when between transmitting coil and receiving coil and transmission range change, due to transmitting coil and repeating coil, have stronger mutual inductance between repeating coil and receiving coil, described system still can be transmitted with higher efficiency.

As shown in Figure 1, the left side is transmitting coil, and the right is receiving coil, and the size of transmitting coil is greater than the size of receiving coil, and namely emitter and receiving system are not symmetrical completely, and its efficiency of transmission can reduce than during same size.In the life and application of reality, people propose larger requirement to the dexterity of electronic product and convenience, and the application of wireless power transmission is also like this, and the size of receiving terminal is often less than the size of transmitting terminal.

As shown in Figure 2, repeating coil of the present utility model greatly enhances the mutual inductance of repeating coil and transmitting coil with the coaxial isoplanar structure of transmitting coil, achieve the amplification to source class electric current, improve the efficiency of transmission of system, and save bulk, reduce the volume of system, be more conducive to application in practice.

As shown in Figure 3, the left side is transmitting coil, and centre is repeating coil, and the right is receiving coil, and transmitting terminal and the receiving terminal of system all adopt cascaded structure, M ₁₂for the coefficient of mutual inductance of transmitting coil and repeating coil, M ₂₃for the coefficient of mutual inductance of repeating coil and receiving coil, Vs is high frequency voltage source, and Rs is the internal resistance of voltage source, R ₁, R ₂, R ₃be respectively the equivalent internal resistance of transmitting coil, repeating coil and receiving coil, C ₁, C ₂, C ₃be respectively the external capacitor of three coils, L ₁, L ₂, L ₃be respectively the self-induction of three coils, R _lit is the load resistance of system.

As follows to the equivalent-circuit model analytical procedure of the asymmetric wireless power transmission systems of insertion repeating coil of the present utility model:

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

$\left[\begin{array}{c}{V}_S\\ 0\\ 0\end{array}\right]=\left[\begin{array}{ccc}{Z}_{11}& \mathrm{j\ω}{M}_{12}& 0\\ \mathrm{j\ω}{M}_{12}& Z_{22}& \mathrm{j\ω}{M}_{23}\\ 0& 0& Z_{33}+\mathrm{j\ω}{M}_{23}\end{array}\right]\left[\begin{array}{c}{i}_1\\ i_2\\ i_3\end{array}\right]$

Wherein, V _sthe output voltage of high frequency signal generator, Z ₁₁, Z ₂₂, Z ₃₃be respectively the impedance loop of transmitting coil loop, repeating coil loop and receiving coil loop, its expression formula is respectively: $Z_{22}=R_2+\mathrm{j\ω}{L}_2+\frac{1}{\mathrm{j\ω}{C}_2},Z_{33}=R_3+\mathrm{j\ω}{L}_3+\frac{1}{\mathrm{j\ω}{C}_3}+R_L;$ M ₁₂for the coefficient of mutual inductance of transmitting coil and repeating coil, M ₂₃for the coefficient of mutual inductance of repeating coil and receiving coil, i ₁, i ₂, i ₃the loop current of transmitting coil loop, repeating coil loop and receiving coil loop respectively.When system works under resonance condition time meet: $\mathrm{\ω}{L}_2=\frac{1}{\mathrm{\ω}{C}_2},\mathrm{\ω}{L}_3=\frac{1}{\mathrm{\ω}{C}_3}.$

2. in pair described step 1, determinant solves, and can obtain i ₁, i ₂, i ₃as described below:

$i_1=\frac{\mathrm{Vs}({\mathrm{\ω}}^2{M}_{23}^2+R_2(R_3+R_L))}{{\mathrm{\ω}}^2{M}_{23}^2(R_1+R_s)+{\mathrm{\ω}}^2{M}_{12}^2(R_3+R_L)+(R_1+R_s)R_2(R_3+R_L)}$

$i_2=\frac{\mathrm{\ω}{M}_{12}(R_3+R_L)R_s}{{\mathrm{\ω}}^2{M}_{23}^2(R_1+R_s)+{\mathrm{\ω}}^2{M}_{12}^2(R_3+R_L)+(R_1+R_s)R_2(R_3+R_L)}$

$i_3=\frac{{\mathrm{\ω}}^2{M}_{12}{M}_{23}\mathrm{Vs}}{{\mathrm{\ω}}^2{M}_{23}^2(R_1+R_s)+{\mathrm{\ω}}^2{M}_{12}^2(R_3+R_L)+(R_1+R_s)R_2(R_3+R_L)}$

3. in pair described step 2, loop current carries out computing, can obtain input power, power output and efficiency of transmission respectively:

$P_{\mathrm{in}}=i_1\mathrm{Vs}=\frac{V_S^2({\mathrm{\ω}}^2{M}_{23}^2+R_2(R_3+R_L))}{{\mathrm{\ω}}^2{M}_{23}^2(R_1+R_S)+{\mathrm{\ω}}^2{M}_{12}^2(R_3+R_L)+(R_1+R_S)R_2(R_3+R_L)}$

$P_{\mathrm{out}}=i_3^2{R}_L=\frac{{\left({\mathrm{\ω}}^2{M}_{12}{M}_{23}\mathrm{Vs}\right)}^2{R}_L}{{({\mathrm{\ω}}^2{M}_{23}^2(R_1+R_S)+{\mathrm{\ω}}^2{M}_{12}^2(R_3+R_L)+(R_1+R_S)R_2(R_3+R_L))}^2}$

$\mathrm{\η}=\frac{P_{\mathrm{out}}}{P_{\mathrm{in}}}=\frac{{\left({\mathrm{\ω}}^2{M}_{12}{M}_{23}\right)}^2{R}_L}{({\mathrm{\ω}}^2{M}_{23}^2(R_1+R_S)+{\mathrm{\ω}}^2{M}_{12}^2(R_3+R_L)+(R_1+R_S)R_2(R_3+R_L))({\mathrm{\ω}}^2{M}_{23}^2+R_2(R_3+R_L))}$

4. in system described in, the radius of transmitting coil, repeating coil, receiving coil is respectively a, b, c, distance between transmitting coil and receiving coil is D, distance between transmitting coil and repeating coil is d, distance then between repeating coil and receiving coil is D-d, then the mutual inductance between transmitting coil and repeating coil is: $M_{12}={\mathrm{\μ}}_0{\left(\mathrm{ab}\right)}^{\frac{1}{2}}\stackrel{\mathrm{\π}}{\sqrt{0^2}}\frac{(2{\sin }^2\mathrm{\θ}-1)\mathrm{d\θ}}{{\left({1-{k_1}^2\sin }^2\mathrm{\θ}\right)}^{\frac{1}{2}}},$ Wherein $k_1^2=\frac{4\mathrm{ab}}{d^2+{(a+b)}^2};$ The mutual inductance of repeating coil and receiving coil is: $M_{23}={\mathrm{\μ}}_0{\left(\mathrm{bc}\right)}^{\frac{1}{2}}\stackrel{\mathrm{\π}}{\sqrt{0^2}}\frac{(2{\sin }^2\mathrm{\θ}-1)\mathrm{d\θ}}{{(1-{k_2}^2{\sin }^2\mathrm{\θ})}^{\frac{1}{2}}},$ Wherein $k_2^2=\frac{4\mathrm{bc}}{{(D-d)}^2+{(b+c)}^2}.$

In the asymmetric wireless power transmission systems of insertion repeating coil of the present utility model, due to the coaxial isoplanar of transmitting coil and repeating coil, so d=0, then the mutual inductance M between transmitting coil and repeating coil ₁₂strengthen, from system transfers efficiency expression formula in described step 3, efficiency and M ₁₂, M ₂₃relevant, and M ₁₂, M ₂₃relevant with d and D-d respectively again, when the distance d when between transmitting coil and repeating coil reduces, the distance D-d between repeating coil and receiving coil increases, then M ₁₂strengthen, M ₂₃weaken, when other parameter constant of system, efficiency of transmission changes with the change of d, from the expression formula of efficiency, when d increases, efficiency eta is almost constant before this, then along with the increase of d, efficiency sharply reduces, it can thus be appreciated that, when distance d when between transmitting coil and repeating coil is very near, efficiency of transmission can reach higher value, consider size and the volume restriction of real system, repeating coil and transmitting coil are remained on coaxial isoplanar by the utility model, the efficiency of transmission of system is not only made to reach high value, and save the volume of system, more be conducive to system application in practice.

The utility model transmitting coil and receiving coil radius are respectively a=30cm, c=10cm, and repeating coil radius is b=50cm, pitch of turn P ₀=2cm, the number of turn is all N=8 circle, and all copper cash radius r=3mm, driving source frequency setting is f ₀=10.6MHz, transmitting coil and receiving coil distance and system transfers distance D=1m, the center of all coils is all on same level axle.Transmitting coil and receiving coil and electric capacity form LC series resonant circuit, and coil resonance is occurred near 10.6MHz.

As shown in Figure 4, near resonant frequency point, the efficiency of transmission of system reaches peak, and its value, close to 1, greatly increases the efficiency of transmission that transmitting coil is greater than this asymmetric magnetic coupling resonance wireless power transmission systems of receiving coil size.

In the utility model experimental model, signal generator is utilized to produce the sine wave signal of 10.6MHz, transmitting coil is loaded into after power amplifier amplifies, just input power can be obtained accordingly, receiving coil connects power meter, measure power output by power meter, the ratio of the two calculates the efficiency of transmission of system.

As shown in Figure 5, the efficiency of transmission of the utility model experimental model reaches peak near resonant frequency point, and its value is close to 0.9, and namely system can be transmitted with higher efficiency.

As shown in Figure 6, the simulation and experiment data of the asymmetric wireless power transmission systems of insertion repeating coil of the present utility model are substantially identical, and consistent with theoretical analysis result.Illustrate in asymmetric system, insert the efficiency of transmission that improve system with the structure of the coaxial isoplanar repeating coil of transmitting coil significantly.

The utility model devises a kind of being greater than at transmitting coil in the magnetic coupling resonance wireless power transmission systems of receiving coil size and inserts and the structure of the coaxial isoplanar repeating coil of transmitting coil, coefficient of mutual inductance between intensifier coil, and then strengthen coupling coefficient and the efficiency of transmission of system, and save bulk, be more conducive to wireless power transmission systems application in practice.

The foregoing is only the utility model preferably execution mode; but protection range of the present utility model is not limited thereto; in every case those of ordinary skill in the art are in the technical scope that the utility model discloses; the equivalence done is modified or conversion, all should be encompassed within protection range of the present utility model.

Claims (7)

1. insert an asymmetric wireless power transmission systems for repeating coil, it is characterized in that, described wireless power transmission systems comprises an emitter, a relay and a receiving system;

Described emitter comprises high frequency signal generator, impedance matching network, power amplifier and transmitting coil, the side of described transmitting coil is connected to high frequency signal generator by impedance matching network, opposite side and receiving coil produce resonance, and energy is vibrated in the form of an electromagnetic wave between two coils;

Described relay comprises a repeating coil, and described repeating coil is arranged with the coaxial isoplanar of transmitting coil, has the identical number of turn and pitch of turn, and described repeating coil is different from transmitting coil radius;

Described receiving system comprises receiving coil, load equipment and power meter, the radius of the radius ratio transmitting coil of described receiving coil is little, its number of turn is identical with transmitting coil with pitch of turn, and described receiving coil side is connected to load equipment and power meter, and opposite side and transmitting coil produce resonance;

Described transmitting coil, repeating coil, receiving coil are on same level axle, and the distance of transmitting coil and receiving coil is 1m.

2. a kind of asymmetric wireless power transmission systems inserting repeating coil according to claim 1, it is characterized in that, described impedance matching network is passive matching network, is made up of electric capacity and inductance.

3. a kind of asymmetric wireless power transmission systems inserting repeating coil according to claim 1, it is characterized in that, described impedance matching network is active matching network, and the source follower be made up of active, passive device, emitter follower and buffer are formed.

4. a kind of asymmetric wireless power transmission systems inserting repeating coil according to claim 1, is characterized in that, described repeating coil is in the outer coiling of transmitting coil.

5. a kind of asymmetric wireless power transmission systems inserting repeating coil according to claim 1, it is characterized in that, described receiving coil is multiturn helical coil, a matching capacitance of connecting, and directly connects AC load equipment.

6. a kind of asymmetric wireless power transmission systems inserting repeating coil according to claim 1, it is characterized in that, described receiving coil is by a rectification circuit supply DC load equipment, and described rectification circuit comprises halfwave rectifier, full-wave rectification and bridge rectifier.

7. a kind of asymmetric wireless power transmission systems inserting repeating coil according to claim 1, it is characterized in that, described transmitting coil, repeating coil and receiving coil utilize himself in high frequency equivalent resistance, parasitic capacitance, matching capacitance and own inductance composition oscillating circuit; Transmitting coil, repeating coil and receiving coil have identical resonance frequency.