Summary of the invention
The present invention has the existing shortcoming that can not pass through intermediate obstacles or transmission range weak point in the wireless energy transmission technology now in order to solve, and a kind of magnet coupled resonant type wireless energy transmission equipment is provided.
The present invention is made up of energy emission source and energy receiver;
Described energy emission source is made up of magnetic field resonant excitation and drive circuit and resonance radiating circuit;
Magnetic field resonant excitation and drive circuit are made up of drive circuit and driving switch pipe, and drive circuit produces identical with the resonance tranmitting frequency of setting or is the drive signal of the 1/n of resonance tranmitting frequency, and the driving switch pipe receives drive signal; The switching frequency of driving switch pipe is identical with the resonance tranmitting frequency or be the 1/n of resonance tranmitting frequency, is used for giving the resonance radiating circuit with the energy supplement of power supply, and n wherein is a positive integer;
The resonance radiating circuit is made up of resonance transmitting coil and resonance emission electric capacity, and resonance transmitting coil and resonance emission electric capacity constitute resonator system, and energy exchanges with magnetic field and electric field form at resonance transmitting coil and resonance emission electric capacity respectively; In the resonance transmitting coil, produce and the identical resonance current of setting of resonance tranmitting frequency; Resonance current in the resonance transmitting coil is formed on the alternating magnetic field in the power transfer scope;
Described energy receiver is made up of resonance receiving circuit and high-frequency rectification circuit;
The resonance receiving circuit is used to receive the magnetic field energy that the resonance radiating circuit transmits; The resonance receiving circuit receives electric capacity by resonance receiving coil and resonance to be formed, and resonance receiving coil and resonance receive electric capacity and is used to set the resonance receive frequency, and the resonance receive frequency of setting is identical with the resonance tranmitting frequency of setting;
The pattern that two resonance coils are formed the field of systems be F (r, t), F (r, t) ≈ a
1(t) F
1(r)+a
2(t) F
2(r), F wherein
1(r) and F
2(r) be respectively the eigenmodes of resonance transmitting coil and resonance receiving coil, a
1(t) and a
2(t) be corresponding field intensity respectively; Work as ω
1=ω
2=ω and a
2(0)=0 o'clock, then
A wherein
1(0) and a
2(0) is respectively the initial value of two resonance conditions; ω
1Be the characteristic frequency of resonance transmitting coil 1-2-1, ω
2Be the characteristic frequency of resonance receiving coil 2-1-1, ω is the characteristic frequency of coil; Set the loss speed that coupling coefficient is far longer than resonant body, then the mutual transmission cycle of energy is π/k between two resonance coils;
High-frequency rectification circuit, the magnetic field energy that the resonance receiving circuit is received is converted into electric energy output;
The resonance receive frequency of setting and the resonance transmit frequency range of setting are between 0.05MHz~50MHz.
The present invention uses two electromagnetic systems with identical particular resonant frequency, at a distance of certain apart from the time because electromagnetic coupled produces resonance, carry out energy delivery.In general, two electromagnetic systems that certain distance is arranged, be weak coupling each other, but if the natural resonance frequency of two systems is identical, then can produce the forceful electric power magnetic resonance, it is exactly a lock that this energy emission source resonance frequency cans be compared to, and the resonance frequency of energy receiver to can be compared to be exactly a key, open different locks with different keys, when the resonance frequency of energy emission source and energy receiver is consistent, promptly opened the gate of energy delivery, constitute an electromagnetic resonance system, if a plurality of resonant bodies are arranged in effective range, then can add this resonator system equally, if a certain end connects power supply constantly for this resonator system provides energy, and the opposing party's consumed energy, then realized the transmission of energy, made the present invention have the advantage (transmission range is times over the length of resonance transmitting coil diameter) of its power transfer distance; And the transmission that has proved energy by experiment is not subjected to the advantage of the influence of barrier in the transmission path.
Another important feature of apparatus of the present invention is that energy transmission efficiency is higher.It has non-radiation type, with the transmitting set of the usefulness of communicating by letter essential distinction is arranged, and it will control the emission that do not generate electromagnetic waves on the contrary, is electromagnetic near field characteristic in order to avoid energy consumption in the space, also can be understood as utilization.Be that when not having receiving system around it, its energy loss mainly is the thermal losses that airborne magnetic resistance loss and emission source internal current produce because emission source produces is high frequency magnetic field, these two losses are all lower under the normal condition.When around it receiving system being arranged, then emission source and receiving system produce resonance, and the energy consumption of emission source mainly is the energy that receiving system consumes, and also comprises above-mentioned two losses simultaneously.Emission source circuit internal loss is low more, and then system effectiveness is high more, and the peak efficiency that can accomplish is 60% at present.
Embodiment one: in conjunction with Fig. 1 present embodiment is described, present embodiment is made up of energy emission source 1 and energy receiver 2;
Described energy emission source 1 is made up of magnetic field resonant excitation and drive circuit 1-1 and resonance radiating circuit 1-2;
Magnetic field resonant excitation and drive circuit 1-1 are made up of drive circuit 1-1-1 and driving switch pipe 1-1-2, drive circuit 1-1-1 produces identical with the resonance tranmitting frequency of setting or is the drive signal of the 1/n of resonance tranmitting frequency, and driving switch pipe 1-1-2 receives drive signal; The switching frequency of driving switch pipe 1-1-2 is identical with the resonance tranmitting frequency or be the 1/n of resonance tranmitting frequency, is used for giving resonance radiating circuit 1-2 with the energy supplement of power supply, and n wherein is a positive integer;
Resonance radiating circuit 1-2 is made up of resonance transmitting coil 1-2-1 and resonance emission electric capacity 1-2-2, resonance transmitting coil 1-2-1 and resonance emission electric capacity 1-2-2 constitute resonator system, and energy exchanges with magnetic field and electric field form at resonance transmitting coil 1-2-1 and resonance emission electric capacity 1-2-2 respectively; In resonance transmitting coil 1-2-1, produce and the identical resonance current of setting of resonance tranmitting frequency; Resonance current among the resonance transmitting coil 1-2-1 is formed on the alternating magnetic field in the power transfer scope;
Described energy receiver 2 is made up of resonance receiving circuit 2-1 and high-frequency rectification circuit 2-2;
Resonance receiving circuit 2-1 is used to receive the magnetic field energy that resonance radiating circuit 1-2 transmits; Resonance receiving circuit 2-1 receives electric capacity 2-1-2 by resonance receiving coil 2-1-1 and resonance and forms, and resonance receiving coil 2-1-1 and resonance receive electric capacity 2-1-2 and is used to set the resonance receive frequency, and the resonance receive frequency of setting is identical with the resonance tranmitting frequency of setting;
High-frequency rectification circuit 2-2, the magnetic field energy that resonance receiving circuit 2-1 is received is converted into electric energy output.
Embodiment two: present embodiment is described in conjunction with Fig. 1, present embodiment and embodiment one difference are that energy emission source 1 has increased power converting circuit 1-3, and power converting circuit 1-3 is used for alternating current being converted to direct current and being transferred to the magnetic field resonant excitation and drive circuit 1-1 and resonance radiating circuit 1-2; Other composition is identical with embodiment one with connected mode.
Embodiment three: in conjunction with Fig. 1 present embodiment is described, present embodiment is that with embodiment one difference the resonance transmitting coil 1-2-1 among the resonance radiating circuit 1-2 adopts serial or parallel connection to be connected with resonance emission electric capacity 1-2-2; Other composition is identical with embodiment one with connected mode.
The resonance frequency of resonance radiating circuit 1-2 is determined by following formula:
C wherein
1There are a plurality of electric capacity simultaneously in electric capacity for resonance emission electric capacity 1-2-2 in the ifs circuit, then need according to physical circuit, calculates equivalent capacity according to the series and parallel relation of electric capacity; L
1It is the inductance of resonance transmitting coil 1-2-1.According to the power transfer needs of reality, determine the inductance L of the resonance transmitting coil 1-2-1 of resonance radiating circuit 1-2
1Capacitor C with resonance emission electric capacity 1-2-2
1Then the resonance tranmitting frequency of circuit can be determined by formula (4), can determine the frequency of the drive signal of driving switch pipe 1-1-2 thus, by the control that driving switch pipe 1-1-2 is turned on and off, in resonance transmitting coil 1-2-1, produce and have the electric current that needs frequency, this electric current generation magnetic field.
Embodiment four: in conjunction with Fig. 1 present embodiment is described, present embodiment is that with embodiment one difference the resonance receiving coil 2-1-1 among the resonance receiving circuit 2-1 adopts serial or parallel connection to be connected with resonance reception electric capacity 2-1-2; Other composition is identical with embodiment one with connected mode.
Energy receiver 2 is according to the resonance receive frequency of resonance tranmitting frequency design of setting or adjustment resonance receiving circuit 2-1.Resonance receiving circuit 2-1 determines that by the resonance receive frequency resonance receiving coil 2-1-1 and resonance receive electric capacity 2-1-2, determines size, material and the inductance value of resonance receiving coil 2-1-1 according to the needs of the power consumption equipment of reality, then according to formula
Calculate the electric capacity that resonance receives electric capacity 2-1-2, guarantee to produce resonance, thereby can realize the transmission of energy with the magnetic field of energy emission source 1.The energy that resonance receiving circuit 2-1 is received uses through offering load behind the rectifying and wave-filtering.
Embodiment five: in conjunction with Fig. 1 present embodiment is described, present embodiment and embodiment one difference are that the resonance receive frequency set and the resonance tranmitting frequency of setting are 0.05MHz~50MHz.Other composition is identical with embodiment one with connected mode.
Resonance frequency used in the present invention can be selected different Frequency point or frequency band according to the needs of aspects such as transmission range and through-put power.
Embodiment six: in conjunction with Fig. 1 present embodiment is described, present embodiment and embodiment one difference are to have in the magnet coupled resonant type wireless energy transmission equipment a plurality of energy receiver 2.Other composition is identical with embodiment one with connected mode.
Embodiment seven: in conjunction with Fig. 1 present embodiment is described, the experiment condition of present embodiment is that the voltage of power supply is the 25v direct current, and power is 120W; The resonance tranmitting frequency of setting and the resonance receive frequency of setting are 310kHz, resonance radiating circuit 1-2 is identical with the parameter of resonance receiving circuit 2-1, wherein the diameter of resonance transmitting coil 1-2-1 and resonance receiving coil 2-1-1 is 500mm, and that winding wire adopts is 0.75mm
2Multi cord, the number of turn is 2 circles, resonance emission electric capacity 1-2-2 and resonance receive electric capacity 2-1-2 and adopt the 4.4nF thin-film capacitor, withstand voltage is 630v.Experimental result is maximum transmission power 100w, and maximal efficiency is 60%, and ultimate range can reach 1 meter.
Principle of the present invention:
The magnet coupled resonant type energy transmission technology is to utilize two electromagnetic systems with identical particular resonant frequency, at a distance of certain apart from the time, produce resonance owing to vibration frequency is identical, carry out energy delivery.As shown in Figure 1,1-3 produces non-radiative magnetic field by the resonance transmitting coil, when resonance receiving coil 2-1 enters this action of a magnetic field zone, owing to having identical frequency of oscillation with this magnetic field, resonance receiving coil 2-1 produces magnetic resonance, energy among the resonance receiving coil 2-1 is constantly assembled, voltage constantly raises, and after follow-up energy reception and change-over circuit 2-2, energy can be offered load and use.In general, electromagnetic system at a distance of certain distance, be weak coupling each other, but, then can produce the forceful electric power magnetic resonance if the natural resonance frequency of two systems is identical, constitute an electromagnetic resonance system, if a plurality of resonant bodies are arranged in effective range, then can add this resonator system equally, if connecting power supply, a certain end constantly provides energy for this resonator system, and the opposing party's consumed energy has then been realized the transmission of energy.Why being called " magnet coupled resonant type ", be because it is alternating magnetic field that the media of energy exchange is carried out in the space, and the object in our surroundings comprises that organism is subjected to the influence in magnetic field very little (electric field then can be caused danger).
A significant advantage in this invention is exactly efficiency of transmission height, quality factor height, and well-known, quality factor are high more, and the loss of energy is more little, helps improving energy transmission efficiency more.The eigenmodes of resonance transmitting coil 1-2-1 and resonance receiving coil 2-1-1 is respectively F
1(r) and F
2(r), the pattern of the field of these two resonance coils composition systems is that (r, t), the application mode coupled wave theory obtains F (r, t) ≈ a to F
1(t) F
1(r)+a
2(t) F
2(r), a wherein
1(t) and a
2(t) be corresponding field intensity respectively, can determine by following equation group:
ω wherein
1,2Be the characteristic frequency of resonance transmitting coil 1-2-1 and resonance receiving coil 2-1-1, Γ
1,2Represented the inherent loss size of resonance transmitting coil 1-2-1 and resonance receiving coil 2-1-1, Γ
1,2Be the inverse (damping) of the damping time constant in the circuit, Γ
1,2Big more resonant body energy loss is fast more; κ is the coupling coefficient of field between two resonant bodies, and κ is big more, and coupling is strong more.
Under the weak coupling situation, has only the ω of working as
1, ω
2In the time of very approaching, coupling just can have influence on a
1And a
2Be far longer than damping at coupling coefficient, just k 〉=Γ
1,2The time, equation solution is obtained following result:
Wherein
a
1(0) and a
2(0) is respectively the initial value (having represented the energy of resonance coil) of two resonance conditions.
Work as ω
1=ω
2=ω and a
2(0)=0 o'clock, can get energy expression formula over time in following two resonance coils of this resonance state by formula (2).
Can be got by formula (3), the energy among the resonance transmitting coil 1-2-1 is
Energy among the resonance receiving coil 2-1-1 is
Concrete variation relation in time is by shown in Figure 2.
This shows that under the weak coupling situation, when coupling coefficient was far longer than the loss speed of resonant body, the mutual transmission of energy was that perfectly the transmission cycle is π/k between two resonance coils.The quality factor of whole energy transmission system are defined as
Quality factor high pass effect more are good more.For realizing energy delivery, need the quality factor of resonant body very high, Γ therefore need reduce the wastage
1,2
Another significant advantage hinders little exactly, the present invention tests the situation that wireless energy transfer penetrates various different barriers, resonance transmitting coil and resonance receiving coil are placed various barriers both sides, test power transfer situation, the result shows, this technology can penetrate various on-metallic articles such as brick wall, books, woodwork, bakelite plate, poly (methyl methacrylate) plate, leather, fabric or the like, and to not influences of index such as the energy transmission efficiency of system, power.Metallic article depends on the circumstances to the influence of this system, less than coil diameter or can't constitute than the metallic conductor in maelstrom or loop near this system the time, influence very little.