WO2013128518A1

WO2013128518A1 - Power transmitting device, power receiving device, power supply system, and electronic device

Info

Publication number: WO2013128518A1
Application number: PCT/JP2012/007312
Authority: WO
Inventors: 小林　直樹; 塚越　常雄; 福田　浩司; 博鳥屋尾
Original assignee: 日本電気株式会社
Priority date: 2012-02-29
Filing date: 2012-11-14
Publication date: 2013-09-06
Also published as: JPWO2013128518A1

Abstract

The invention addresses the problem of providing, in wireless power supply, a power supply system capable of maintaining a relatively high power transmission efficiency even when a power transmission distance is long. A power transmitting coil unit (210) has a plurality of resonance coils (221) arranged so as to form a periodical structure. The resonance coils (221) form a transmission line for an electromagnetic wave, and a standing wave of an electromagnetic propagating wave occurs in the power transmitting coil unit (210). Similarly, a power receiving coil unit (310) has a plurality of resonance coils (321) arranged so as to form a periodical structure. The power transmission efficiency is maintained relatively high even if the distance between a power transmitting device (200) and a power receiving device (300) exceeds twice.

Description

Power transmission device, power reception device, power supply system, and electronic device

The present invention relates to a power transmission / reception system, and more specifically, to a system for supplying power to a power receiving device in a contactless manner without going through a power transmission line.

A method of supplying power wirelessly to a separated power receiving apparatus is known.
For example, Japanese Patent Laid-Open No. 2008-66841 (Patent Document 1) discloses a configuration in which an electromagnetic wave propagates in an electromagnetic wave transmission sheet and an electromagnetic field leaking from the sheet is supplied to a power receiving device (in addition, JP 2007-281678 (Patent Document 2)).

Alternatively, Japanese Patent Laid-Open No. 2008-259392 (Patent Document 3) discloses a power transmission method using a microwave beam. For example, solar power generation is performed on a sanitary orbit, and the energy is transmitted to the ground with a microwave beam. Then, the microwave is reconverted into electric power by the ground power receiving system.

Further, for example, as disclosed in Japanese Patent Application Laid-Open No. 7-322534 (Patent Document 4), there is a method of transmitting electric power from a power source side primary coil to a load side secondary coil by electromagnetic induction. This is often used to charge small household electronic devices such as shavers and electric toothbrushes.

Further, in electromagnetic induction, the power supply source and the power supply destination (power receiving side) must be very close to each other, but power transmission using an electromagnetic resonance phenomenon has also been proposed in order to eliminate this drawback (Japanese Patent Laid-Open No. 2011-2011). No. 147271 (Patent Document 5), US7825543B2 (Patent Document 6)).

JP 2008-66841 A JP 2007-281678 A JP 2008-259392 A JP-A-7-322534 JP 2011-147271 A US Pat. No. 7,825,543

The methods using electromagnetic resonance as in

Patent Documents

5 and 6 have an advantage that the power transmission distance can be extended as compared with the electromagnetic induction method.
However, even the method of Patent Document 5 has a problem that the power transmission efficiency is extremely lowered when the power transmission distance exceeds about twice or three times the diameter of the power transmission coil.

Therefore, an object of the present invention is to provide a power transmission device, a power reception device, and a power supply system that can maintain a relatively high power transmission efficiency even when a power transmission distance is long in wireless power feeding.

The power transmission device of the present invention is
A power transmission coil unit that has a plurality of resonance coils arranged so as to form a one-dimensional periodic structure, and transmits power to the power reception device by magnetic field resonance with the power reception device;
A power supply unit that supplies power to the power transmission coil unit,
The power transmission coil section is used as a transmission path for electromagnetic propagation waves, and a standing wave of electromagnetic propagation waves is generated in the power transmission coil section.

The power receiving device of the present invention is
A plurality of resonance coils arranged so as to form a one-dimensional periodic structure, and a power receiving coil unit that receives power from the power transmission device by magnetic field resonance with the power transmission device;
A power receiving unit that receives power from the power receiving coil unit,
The power receiving coil portion serves as an electromagnetic propagation wave transmission path, and a standing wave of the electromagnetic propagation wave is generated in the power receiving coil portion due to magnetic field resonance with the power transmission device.

A power supply system according to the present invention includes the power transmission device and the power reception device.

According to such a configuration, there is an effect that the power transmission efficiency can be kept high even if the power transmission distance is relatively long.

The lineblock diagram of the electric power supply system concerning a 1st embodiment. The block diagram of the electric power supply system as background art. The figure which shows the result of having measured distance and changing power transmission efficiency by 1st Embodiment and background art. The figure which shows the example of the structure which arranged the some resonance coil. The figure which shows a dispersion | distribution curve. The figure which shows the equivalent circuit of the coil periodic structure in which the some resonance coil was located in a line. The figure which shows the equivalent circuit of the circuit of FIG. The figure which shows the equivalent circuit of the circuit of FIG. The equivalent circuit diagram of one unit of a periodic structure. The figure which shows the state in which the standing wave has arisen in three resonance coils. The figure which shows the state in which the standing wave has arisen in three resonance coils. The figure which shows the state in which the standing wave has arisen in three resonance coils. The figure which shows the magnetic field loop which arises in a power transmission coil part and a receiving coil part. The figure which shows the magnetic field loop which arises in a power transmission coil part and a receiving coil part. The figure which shows the modification 1. FIG. The figure of the experimental result which shows the difference in the power transmission efficiency at the time of changing the distance from a floor surface. The figure which shows the modification of the position which arrange | positions a feed coil. The figure which shows a mode that a dispersion | distribution curve is shifted. The figure which shows the modification 4. The figure which shows an example of a planar spiral coil. The figure which shows an example of the coil mounted in the back surface of a printed circuit board. The figure which shows the example of the structure which arranged the power transmission coil part two-dimensionally.

(First embodiment)
FIG. 1 is a configuration diagram of a power supply system according to the first embodiment of the present invention.
The power supply system 100 includes a power transmission device 200 and a power reception device 300.
Here, for easy understanding, the front-rear direction is determined for each of the power transmission device 200 and the power reception device 300.
In this specification, the power transmission device 200 and the power reception device 300 are arranged at a distance, and the power reception device 300 side of the power transmission device 200 is the front side. The side farther from the power receiving device 300 in the power transmitting device 200 is the rear side.
Similarly, in the power receiving device 300, the power transmission device 200 side is defined as the front side. The side farther from the power transmission device 200 in the power reception device 300 is the rear side.

The power transmission device 200 includes a power transmission coil unit 210 and a power feeding unit 280.
The power transmission coil unit 210 includes a front coil unit 220, a rear coil unit 230, and a power feeding coil 240.
The pre-stage coil unit 220 is composed of one resonance coil. This resonance coil is referred to as a front coil 221. The front coil 221 is a spring-type coil, and is disposed on the front side (that is, the power reception device 300 side) of the power supply coil 240.
The rear coil unit 230 has two spring type coils, and is arranged behind the power supply coil 240 (that is, on the side far from the power receiving device 300).
Here, it is assumed that the first rear coil 231 and the second rear coil 232 are from the side closer to the feeding coil 240. That is, the feeding coil 240 is disposed so as to be sandwiched between the front coil 221 and the first rear coil 231.

The front coil 221, the first rear coil 231 and the second rear coil 232 are arranged at a constant pitch.
In this specification, a structure configured by periodically arranging a plurality of resonance coils is referred to as a “coil periodic structure”.

In FIG. 1, the axis of the front coil 221, the axis of the feeding coil 240, the axis of the first rear coil 231, and the axis of the second rear coil 232 are substantially coaxial, but the axes intersect each other. An angle may be attached as follows.
In FIG. 1, the front coil 221, the first rear coil 231, and the second rear coil 232 are arranged at a substantially constant pitch. The arrangement pitch may be slightly deviated within the propagation range.
The pre-stage coil 221, the first post-stage coil 231 and the second post-stage coil 232 have the same coil characteristics and the same resonance (resonance) frequency. That is, the resonance coils having different characteristics are not arranged, but a plurality of resonance coils having the same characteristics are arranged.

However, even if the coil characteristics are the same, the resonance frequency may be shifted within a range in which the electromagnetic wave can propagate. For example, even in a coil having the same characteristics, strictly speaking, the resonance frequency varies due to manufacturing errors.
The smaller the error is, the more desirable electromagnetic propagation characteristics can be obtained. For example, when using a plurality of coils having a resonance frequency in the vicinity of 8.6 MHz, it is preferable that the resonance frequency variation is about 10 kHz or less than the resonance frequency variation is about 100 kHz. Propagation characteristics can be obtained.

In this regard, Japanese Patent Application Laid-Open No. 2011-147271 only includes a plurality of resonance coils having different resonance frequencies so as to be compatible with a plurality of frequencies.
Japanese Unexamined Patent Application Publication No. 2011-147271 discloses that a plurality of resonance coils are arranged as a transmission line as in the present embodiment, and that the transmission efficiency is improved by controlling the near magnetic field distribution. Not disclosed.

The power feeding unit 280 includes a power source 281, a power application unit 282, and a frequency control unit 283.
The power application unit 282 applies power to the feeding coil 240.
Here, the power application unit 282 causes an alternating current having a controlled frequency to flow through the feeding coil 240.
The frequency control unit 283 controls the frequency of the current applied to the power feeding coil 240 by, for example, switching.
Although not explicitly shown, the frequency control unit 283 may be provided with an adjusting unit for the user to manually adjust the frequency.

The configuration of power reception device 300 is basically the same as that of power transmission device 200, and includes power reception coil unit 310 and power reception unit 380.
The power receiving coil unit 310 includes a front coil unit 320, a rear coil unit 330, and a power receiving coil 340.
The pre-stage coil unit 320 is composed of one resonance coil, and this is referred to as a pre-stage coil 321.
The rear coil unit 330 includes a first rear coil 331 and a second rear coil 332.
The power receiving coil 340 is disposed between the front coil 321 and the first rear coil 331.
The power receiving unit 380 supplies the received power to the load 900 after rectifying the power received by the power receiving coil 340 or performing voltage conversion.

In such a configuration, when power is applied from the power application unit 282 to the power supply coil 240, electromagnetic waves are transmitted from the power transmission coil unit 210.
The received electromagnetic wave is received by the receiving coil unit 310 and the electric power is taken out from the receiving coil 340.

The configuration of the present embodiment is compared with the background art.
FIG. 2 is a configuration diagram of a power supply system 10 as a background technique using an electromagnetic resonance phenomenon.
A front coil 30 for power transmission is disposed in front of the power feeding coil 20, but no coil is disposed in the rear stage of the power feeding coil 20.
Similarly, the pre-stage coil 50 is arranged at the front stage of the power receiving coil 40, but the coil is not arranged at the rear stage of the power receiving coil 40.
2 is different from the configuration of the first embodiment in whether the power transmission coil unit 210 and the power reception coil unit 310 have a plurality of resonance coils.

The power transmission efficiency is compared between the present embodiment of FIG. 1 and the background art of FIG.
FIG. 3 is a result of measuring the power transmission efficiency by changing the distance between the first embodiment (FIG. 1) and the background art (FIG. 2).
In the graph of FIG. 3, the horizontal axis is the distance [m], and the vertical axis is the logarithm of the power transmission efficiency [%].
The diameter of each coil was 20 cm, the height was 10 cm, and the number of turns was 19.
The resonance frequency of each coil was adjusted to be around 8.64 MHz by cutting the copper wire at the coil end so that the variation was within 10 kHz.
That is, the frequency of the power supplied to the power supply coils 20 and 240 was adjusted to 8.64 MHz.

Referring to FIG. 3, until the distance is around 50 cm, there is almost no difference in power transmission efficiency between the first embodiment and the background technology, or rather, the power transmission efficiency of the background technology is higher. However, the power transmission efficiency of the first embodiment is increased when the distance exceeds 50 cm. In the background art, the power transmission efficiency decreases as the distance increases. However, according to the configuration of the first embodiment, the power transmission efficiency does not decrease even when the distance increases, and is slightly increased depending on the viewpoint. Looks like.
Since the diameter of one coil is 20 cm, it can be said that the present embodiment is more effective when the power transmission distance exceeds 2 to 3 times the coil diameter.
Thus, according to this embodiment, it turns out that there exists an effect which can lengthen power transmission distance, keeping power transmission efficiency high.

(Principle explanation)
The reason why the effects of the present embodiment occur as described above is not necessarily clear, but the idea of the present inventors will be briefly described below.
Even if the current explanation of the principle includes an error, the operation and effect are not denied as well as the configuration of the present invention.
As a result of diligent research, the present inventors have conceived that a plurality of resonance coils are arranged to form a periodic structure, which is regarded as an electromagnetic field transmission line. Furthermore, when this periodic structure was resonated in a specific frequency band, the idea was that this structure itself could be treated as a metamaterial. Therefore, a method for analytically handling the electromagnetic field distribution generated in the periodic structure (transmission line) was pursued, and this could be achieved. In other words, a method has been developed to analytically determine what wave propagation mode occurs in the periodic structure of the resonant coil.

As a result, for example, when a plurality of resonance coils 401 are arranged as shown in FIG. 4, it is possible to determine what mode of electromagnetic wave is generated there.
Hereinafter, this wave is referred to as “electromagnetic propagation wave”.
That is, the present inventors expressed the relationship between the frequency (f) and the wave number (k) of the electromagnetic propagation wave that can occur in the periodic structure of the coil as a dispersion curve as shown in FIG.
d represents one cycle length of the periodic structure, and is, for example, a center-to-center distance between adjacent coils. Therefore, “wave number (k) × one cycle length (d)” which is the horizontal axis of the graph of FIG. 5 means a phase change per cycle length.

In the dispersion curve of FIG. 5, at a frequency f between f _max and f _min , it can be seen that the coil periodic structure can be treated as an electromagnetic wave propagation region, that is, a transmission line when this structure is regarded as a metamaterial. . The inventors have come up with a configuration in which an arbitrary electric field distribution is generated in the periodic structure (transmission line).

(Theory for obtaining the dispersion curve of electromagnetic wave propagation)
A method of obtaining a dispersion curve of electromagnetic propagation waves generated there by treating a resonance coil periodic structure in which resonance coils 401 are periodically arranged as a metamaterial will be described.
Here, as the resonance coil 401, a spring type coil is taken as an example.
An arrangement structure in which a plurality of coils 401 are arranged coaxially as in the power transmission coil unit 210 in FIG. 1 is replaced with the equivalent circuit in FIG. 6.
Here, M is a mutual inductance between adjacent coils 401.
In addition, the capacitance component C is explicitly extracted, and the resistance component is ignored.
Moreover, the black circle in a figure shows the polarity of winding.

Further, the circuit of FIG. 6 can be equivalently converted as shown in FIG.
In FIG. 7, one coil 401 is depicted as being divided into two

coil components

401h and 401h.
Therefore, the inductance of one coil component 401h is L / 2.

Furthermore, the circuit of FIG. 7 can perform equivalent conversion as shown in FIG. 8 while paying attention to the polarity of the coil.

Furthermore, one unit (one unit) of this periodic structure can be redrawn in the equivalent circuit of FIG.

Then, one unit (one unit) of the periodic structure can be expressed by the T matrix as follows.

Let d be the periodic interval (distance between the centers of the coils) of this periodic structure.
Further, when the periodic structure is a metamaterial, the wave number in the traveling direction of the electromagnetic propagation wave traveling through the metamaterial is k _x .
Then, k _x × d represents the phase of the wave for each period, and the following equation is established.

Using the above equation, the dispersion relationship can be obtained by plotting the relationship between the phase (k _x × d) and the frequency f (= ω / 2π).
Thereby, the frequency band (f _min <f <f _max ) of the wave (electromagnetic field) generated in the metamaterial is obtained. That is, the dispersion curve of FIG. 3 can be drawn in the frequency band (f _min <f <f _max ).

So far, the dispersion curve when the coil periodic structure is a metamaterial has been obtained.
When any power is supplied to this coil periodic structure, an electromagnetic field is transmitted to the adjacent resonance coil, and the coil periodic structure becomes a transmission line for electromagnetic propagation waves. Furthermore, if the transmission line loss is small, the electromagnetic field distribution on the transmission line is a so-called standing wave distribution.

It turned out that a standing wave can be generated in a transmission line with a coil periodic structure. Furthermore, if a wave that satisfies the resonance condition of the coil periodic structure is generated, the number of antinodes of the standing wave (electromagnetic propagation wave) can be controlled.
The number of coils is n, the coil interval is d, and the phase between adjacent coils (phase with respect to a certain frequency f in the dispersion curve) is X (= kx × d) [radian].
If the resonance condition is satisfied, the following equation is established.

(N-1) X = mπ (m is an integer)

Here, since the phase X is 0 ≦ X ≦ π, m satisfying the above equation is n, m = 0, 1,... N−1.
For example, when the number of coils is nine (n = 9), there are phases X that satisfy nine resonance states of m = 0, 1,.
By controlling the frequency of the feed power (for example, the frequency of the alternating current) to achieve a resonance state, a standing wave of electromagnetic propagation waves can be generated in the coil periodic structure (see, for example, FIG. 4).

Note that m = 0 means that all coils are in phase as shown in FIG. 10, and that the magnetic field vector is in phase with all coils.
In this case, the number of nodes is 0 and the number of bellies is 1.

For example, m = 1 means that the number of nodes is 1 and the number of antinodes is 2.
In the case of n = 3, as shown in FIG. 11, the magnetic field vectors are opposite to each other in the coils at both ends, and the center is a node.

For example, m = 2 means that the number of nodes is 2 and the number of bellies is 3.
In the case of n = 3, as shown in FIG. 12, the magnetic field vector is shifted by 180 ° for each period.

It is considered that magnetic resonance generated in the power transmission coil unit 210 and the power reception coil unit 310 can be controlled using such a phenomenon.
As shown in FIG. 13, it is assumed that the power transmission coil unit 210 and the power reception coil unit 310 are configured by three coils.
Then, it is assumed that the frequency of the current applied to the feeding coil 240 is selected so as to select the resonance mode of m = 1. Then, stable standing waves are generated in the three coils (221, 231, 232) of the power transmission coil unit 210, and when a magnetic field loop is illustrated, the front coil 221 and the power receiving coil of the power transmission coil unit 210 as illustrated in FIG. It is possible to share (resonate) one magnetic field loop with the pre-stage coil 321 of the part 310 and to make the respective magnetic field loops with the respective

post-stage coil parts

230 and 330.
This can be regarded as controlling a nearby magnetic field by arranging a plurality of resonance coils.
As a result, the power transmission efficiency from the power transmission coil unit 210 to the power reception coil unit 310 can be increased as compared with the background art.

On the other hand, both the power transmission coil unit 210 and the power reception coil unit 310 are configured by three resonance coils. If the power transmission coil unit 210 and the power reception coil unit 310 are simply brought too close to each other, standing waves are generated by the six resonance coils. As a result, six resonance states occur.
Therefore, the above-described resonance mode of m = 1 in the three resonance coils does not occur neatly.
In this case, it is not necessarily the structure which improves power transmission efficiency.
When the power transmission coil unit 210 and the power reception coil unit 310 are separated from each other and each coil unit reaches a distance that can be regarded as an independent electromagnetic propagation structure, a resonance mode of m = 1 in the three resonance coils is apparently generated. Efficiency is improved.

As shown in FIG. 14, when the power transmitting / receiving

coil sections

210 and 310 are each constituted by three resonance coils, resonance states of m = 0 in the three resonance coils are generated in both the power transmission / reception coils, and all the coils have the same phase. There is also a frequency at which magnetic field resonance in which power is transmitted occurs.
However, according to the experiment, the effect as the resonance mode of m = 1 mentioned above is not obtained.

If the number of resonance coils and the characteristics of the resonance coils are changed or the distance between the power transmission coil unit 210 and the power reception coil unit 310 is changed, the optimum magnetic field resonance state differs from the example of FIG. Of course.
However, a stable standing wave can be created by creating a resonance state in the power transmission coil unit 210 (or the power reception coil unit 310) constituted by a plurality of resonance coils, and the power transmission coil unit 210 can thereby generate a power reception coil unit 310. There will be no change in the efficiency of power transmission.

(Modification 1)
By appropriately adjusting the distance between the configuration of the first embodiment and the floor surface, it is possible to further improve the power transmission efficiency.
FIGS. 15 and 16 are a measurement system explanatory diagram and measurement results showing this.
As shown in FIG. 15, the distance between the coil periodic structure (the power transmission coil unit 210 and the power reception coil unit 310) and the floor surface 800 is set to 20 cm or 60 cm.
FIG. 16 shows the results of measuring the power transmission efficiency in the above two cases.
From FIG. 16, it can be seen that when the distance from the floor 800 is set to 20 cm, the power transmission efficiency is improved at a certain distance from the floor 800, rather than from 60 cm.
That is, it is possible to further improve power transmission efficiency by skillfully utilizing the distance between the floor surface 800 and the coil periodic structure (the power transmission coil unit 210 and the power reception coil unit 310).
Furthermore, not only the floor surface but also a material that reflects or shields electromagnetic waves, such as a metal plate, may be skillfully used to improve power transmission efficiency.

(Modification 2)
In the said 1st Embodiment, the case where the power transmission coil part 210 and the receiving coil part 310 were each comprised by the three resonance coils was illustrated.
On the other hand, you may increase the number of the resonance coils which comprise the power transmission coil part 210, such as four and five, for example.
Similarly, you may increase the number of resonance coils which comprise a receiving coil part, such as four and five.

(Modification 3)
In the above embodiment, in both the power transmission coil unit 210 and the power reception coil unit 310, the power supply coil 240 (power reception coil 340) is disposed immediately behind the front coil 221 (321).
On the other hand, the power feeding coil 240 (power receiving coil 340) may be disposed anywhere between the plurality of resonance coils arranged.
For example, as shown in FIG. 17, a feeding coil (or a receiving coil) may be arranged between the second and third from the front (right) while seven or more coils are arranged.
In this case, it may be interpreted that the front coil part (220) is composed of two

resonance coils

221 and 222, and the rear coil part is composed of the third and subsequent coils.

(Modification 4)
The impedance of the resonance coil may be variable.
By making the impedance of the resonance coil variable, the dispersion curve can be shifted as shown in FIG.
In controlling the impedance of the resonance coil, the dielectric constant or magnetic permeability of the coil core may be controlled, or a variable capacitance may be added to the resonance coil to change the capacitance value of the variable capacitance.
As shown in FIG. 19, an impedance control unit 284 is provided in the power feeding unit.
As described above, if the coil impedance is variable on the power transmission coil unit 210 side, a desired resonance state can be created in the power transmission coil unit 210 with respect to the fixed frequency.
Although not shown, if the coil impedance is variable on the power receiving coil unit 310 side, a desired resonance state can be created in the power receiving coil unit 310 with respect to the received frequency.
When changing the coil impedance, the impedances of all the coils constituting the power transmission coil unit may be changed at the same time, or the impedances of the individual coils may be individually changed and adjusted. Good.
Similarly, with respect to the power receiving apparatus, the impedances of all the coils may be changed at the same time, or the impedances of the individual coils may be individually changed and adjusted.

(Modification 5)
In the above embodiment, a spring type coil is exemplified as the resonance coil.
As the resonance coil, for example, a planar spiral coil shown in FIG. 20A may be used.
The planar spiral coil 501 has an advantage that it can be mounted on a printed circuit board.
That is, one spiral coil 501 may be mounted on the front surface or the back surface of the printed board.
Alternatively, planar spiral coils may be mounted on both sides of the printed board.
For example, the planar spiral coil 501 of FIG. 20A is mounted on the front side of the printed board.
Then, the coil 502 of FIG. 20B is mounted on the back surface of the printed board.
FIG. 20B is a perspective view of the coil 501 mounted on the back surface of the printed circuit board from the front surface side.
At this time, a continuous spiral shape can be formed as double-sided mounting by conducting conductor connection between the front side coil 501 and the back side coil 502 at the junction point 503.
Although the case of surface mounting and double-sided mounting has been described here, various types of spiral conductors can be mounted on the multilayer substrate by using the spiral conductors of the respective layers and the conductors connecting the layers.
20A and 20B exemplify a spiral coil having a rectangular shape and each side of the rectangle having a linear shape, it goes without saying that it may be a curved spiral.

Moreover, the spiral coil may be mounted on the high dielectric substrate.
Alternatively, a spiral coil may be mounted on the magnetic material.
Thereby, magnetic flux density can be raised and size reduction of a resonance body (coil) can be achieved.

The space between the power transmission device and the power reception device is generally air, but water, seawater, soil, or a wall may be provided between the power transmission device and the power reception device.

A plurality of power transmission coil units (or power reception coil units) may be two-dimensionally arranged.
Further, for example, as shown in FIG. 21, a plurality of power transmission coil sections (or power reception coil sections) arranged two-dimensionally are sandwiched between two

rigid boards

611 and 612, and the power transmission coil section (or power reception coil section) ) May be rigid so that it does not bend.
Alternatively, the power transmission coil unit or the power reception coil unit may be flexibly bent by sandwiching the resonance coil between two sheets having flexibility.

In this specification, the term “periodic structure” is used to express that the power transmission coil unit (or the power receiving coil unit) is composed of a periodic structure including a plurality of resonance coils.
Here, the periodic structure should not be construed to be limited to an array structure with a strictly constant pitch.
The period may not be strictly constant, and it is allowed that the arrangement pitch of the resonance coils is deviated within a range in which the power transmission coil unit (or power reception coil unit) can be handled as a metamaterial in view of the whole purpose of the present invention.
Further, in the case of an actual product, the arrangement pitch of the resonance coils is designed in consideration of manufacturing restrictions, so that the arrangement period is allowed to deviate depending on the manufacturing conditions.

Examples of the load that receives power supply from the power receiving device include various applied products such as various sensors, household appliances, portable terminals, and electric vehicles.

In the said embodiment, one power transmission coil part was equipped with one coil periodic structure.
Similarly, one power receiving coil portion has one coil periodic structure.
This is because the frequency of magnetic field resonance between the power transmission coil unit and the power reception coil unit is one, but both the power transmission coil unit and the power reception coil unit may have a plurality of coil periodic structures.
For example, when a plurality of coil periodic structures are provided in one power transmission coil unit (or power receiving coil unit), a second coil periodic structure may be provided inside the first coil periodic structure.
According to such a configuration, power can be transmitted at one frequency, and a signal can be transmitted at another frequency.

Note that the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit of the present invention.

The present invention has been described above with reference to the embodiment, but the present invention is not limited to the above. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the invention.

This application claims priority based on Japanese Patent Application No. 2012-043772 filed on February 29, 2012, the entire disclosure of which is incorporated herein.

DESCRIPTION OF SYMBOLS 100 ... Electric power supply system, 200 ... Power transmission apparatus, 210 ... Power transmission coil part, 220 ... Pre-stage coil part, 221 ... Pre-stage coil part, 230 ... Rear stage coil part, 231 ... 1st latter stage coil, 232 ... 2nd latter stage coil, 240 ... feeding coil, 280 ... feeding part, 281 ... power supply, 282 ... power application part, 283 ... frequency control part, 284: Impedance control unit, 300 ... Power receiving device, 310 ... Power receiving coil unit, 320 ... Pre-coil unit, 321 ... Pre-coil, 330 ... Post-coil unit, 331 ... First rear coil, 332 ... Second rear coil, 340 ... Power receiving coil, 380 ... Power receiving unit, 401 ... Resonance coil, 401 ... Coil, 401h ... Coil component, 501 ··coil 502 ... coil, 503 ... junction, 611 ... substrate, 900 ... load.

Claims

A power transmission coil unit that has a plurality of resonance coils arranged so as to form a one-dimensional periodic structure, and transmits power to the power reception device by magnetic field resonance with the power reception device;
Power supply means for supplying power to the power transmission coil unit,
The power transmission coil unit is used as a transmission path for electromagnetic propagation waves, and a standing wave of electromagnetic propagation waves is generated in the power transmission coil means.
The power transmission device according to claim 1,
The power transmission coil unit further includes a power supply loop coil that receives power from the power feeding means,
The power feeding device, wherein the power feeding loop coil is disposed in a gap between the resonance coils.
The power transmission device according to claim 2,
The power feeding device, wherein the power feeding loop coil is disposed between a resonance coil located closest to the power receiving device and a resonance coil located second closest to the power receiving device.
The power transmission device according to any one of claims 1 to 3,
The number of the resonance coils is three.
In the power transmission device according to any one of claims 1 to 4,
The plurality of resonance coils are arranged so as to be coaxial.
In the power transmission device according to any one of claims 1 to 5,
An electromagnetic wave shielding material is disposed in the vicinity of the power transmission coil unit.
In the power transmission device according to any one of claims 1 to 6,
One or more of the plurality of resonance coils have variable impedance.
A plurality of resonance coils arranged so as to form a one-dimensional periodic structure, and a power receiving coil unit that receives power from the power transmission device by magnetic field resonance with the power transmission device;
Power receiving means for receiving power from the power receiving coil unit,
The power receiving device, wherein the power receiving coil portion serves as an electromagnetic propagation wave transmission path, and a standing wave of the electromagnetic propagating wave is generated in the power receiving coil portion by magnetic field resonance with the power transmitting device.
The power receiving device according to claim 8, wherein
The power receiving coil portion further includes a power receiving loop coil,
The power receiving loop coil, wherein the power receiving loop coil is disposed in a gap between the resonance coils.
The power receiving device according to claim 9,
The power receiving loop coil is disposed between a resonance coil located closest to the power transmission device and a resonance coil located second closest to the power transmission device.
The power receiving device according to any one of claims 8 to 10,
The number of the resonance coils is three.
The power receiving device according to any one of claims 8 to 11,
The plurality of resonance coils are arranged so as to be coaxial with each other.
The power receiving device according to any one of claims 8 to 12,
A power receiving device, wherein an electromagnetic shielding material is disposed in the vicinity of the power receiving coil section.
The power receiving device according to any one of claims 8 to 13,
One or more of the plurality of resonance coils have variable impedance.
A power transmission device according to any one of claims 1 to 7,
A power supply system comprising: the power receiving device according to any one of claims 8 to 14.
The power supply system according to claim 15, wherein
A distance between the power transmission device and the power reception device is at least twice the diameter of the resonance coil.
An electronic device comprising the power transmission device according to any one of claims 1 to 7.
An electronic device comprising the power receiving device according to any one of claims 8 to 14.