JP6293363B2 - Resonant power transmission system and resonator - Google Patents

Description

  The present invention relates to a resonant power transmission system and a resonator that perform power transmission at a specific resonance frequency between a transmission-side resonator having a transmission coil and a reception-side resonator having a reception coil.

  As a conventional resonance type power transmission system, one in which a coil of a resonator is supported by a support member containing a dielectric ceramic material as a main component is known (see, for example, Patent Document 1). This support member increases the parasitic capacitance of the resonator, makes it easy to ensure the resonance characteristics, and allows the resonator to be downsized. In addition, since the coil wire length can be shortened, the conductor loss is reduced. Therefore, the heat generation of the resonator due to the conductor loss can be suppressed.

  In addition, an antenna (coil) embedded in a dielectric to increase the dielectric constant is also known (see Non-Patent Document 1, for example). Thereby, the electrostatic capacitance of the antenna can be increased, and the resonance frequency of the antenna can be lowered.

JP 2014-138509 A

2013 IEICE General Conference BCS-1-15 “Study on Spiral Antenna for Wireless Power Transmission Using Dielectric Loaded Tape Structure” Nagoya Institute of Technology

  As described above, in the conventional configuration disclosed in Patent Document 1 and Non-Patent Document 1, the resonance frequency of the resonator is reduced using a dielectric. However, in these conventional configurations, no measures are taken against fluctuations in the distance between the transmission-side resonator and the reception-side resonator and fluctuations in the load connected to the reception-side resonator. That is, when the resonance condition is deviated due to the above fluctuation, in the conventional configuration, it is necessary to keep the resonance characteristic constant by using an external circuit composed of an element such as a resonance capacitor. However, this external circuit has a problem that it cannot be used under the conditions of high voltage and high current due to the restriction due to the rating (voltage, current) of the element.

  The present invention has been made in order to solve the above-described problems, and is capable of adjusting the resonance condition of the power transmission antenna and capable of transmitting power even at a higher voltage and higher current than the conventional technology. An object of the present invention is to provide a power transmission system and a resonator.

A resonance type power transmission system according to the present invention is a resonance type power transmission system that performs power transmission at a specific resonance frequency between a transmission side resonator having a transmission coil and a reception side resonator having a reception coil. And a dielectric that is disposed opposite to a surface perpendicular to the axial direction of at least one of the receiving coils, and at least one of an area facing the coil and a distance between the coil and the coil is variable. The dielectric is composed of a plurality of members that are separable and have different dielectric constants .

  According to the present invention, since it is configured as described above, the resonance condition of the power transmission antenna can be adjusted, and power transmission can be performed even at a higher voltage and higher current than those of the prior art.

It is a block diagram which shows the structural example of the resonance type electric power transmission system which concerns on Embodiment 1 of this invention. It is a figure which shows the structural example of the resonator which concerns on Embodiment 1 of this invention, (a) It is a perspective view, (b) It is a top view. It is a perspective view which shows the operation example in the case of changing the opposing area with the coil of the dielectric material in Embodiment 1 of this invention. It is a perspective view which shows the operation example in the case of changing the distance with the coil of the dielectric material in Embodiment 1 of this invention. It is a figure which shows the example of adjustment of the resonance conditions in the resonator which concerns on Embodiment 1 of this invention. It is a figure which shows the example of adjustment of the resonance conditions in the resonator which concerns on Embodiment 1 of this invention. FIG. 10 is a top view showing another operation example in the case of changing the facing area between the dielectric and the coil in the resonator according to the first embodiment of the present invention. It is a top view which shows another structural example of the resonator which concerns on Embodiment 1 of this invention. It is a top view which shows another structural example of the resonator which concerns on Embodiment 1 of this invention. In the resonator which concerns on Embodiment 1 of this invention, it is a schematic diagram which shows the example which automated the operation | movement when changing the opposing area of a dielectric material and a coil. It is a perspective view which shows the structural example of the resonator which concerns on Embodiment 2 of this invention. It is a perspective view which shows the structural example of the resonator which concerns on Embodiment 3 of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a block diagram showing a configuration example of a resonant power transmission system according to Embodiment 1 of the present invention.
As shown in FIG. 1, the resonant power transmission system includes a transmission device 1 having a transmission-side resonator 13 and a reception device 2 having a reception-side resonator 21. In this resonant power transmission system, power is transmitted from the transmission device 1 to the reception device 2 when the reception-side resonator 21 approaches the transmission-side resonator 13.

  As illustrated in FIG. 1, the transmission device 1 includes a primary power supply 11, a transmission power supply 12, and a transmission-side resonator 13.

The primary power supply 11 outputs DC or AC power.
The transmission power supply 12 converts the DC or AC power (input power) from the primary power supply 11 into power (high frequency power) that matches the resonance frequency of the transmission-side resonator 13 and outputs it. Further, the transmission power supply 12 has a function (parameter detection unit) that detects a parameter related to the transmission power supply 12 that changes when the reception-side resonator 21 approaches the transmission-side resonator 13 by its own protection function. As illustrated in FIG. 1, the transmission power supply 12 includes an inverter circuit 121, an input detection unit 122, a power supply parameter detection unit 123, and an output detection unit 124.

The inverter circuit 121 converts input power from the primary power supply 11 into high-frequency power for output to the transmission-side resonator 13.
The input detection unit 122 detects a parameter related to power input from the primary power supply 11 to the transmission power supply 12. At this time, the input detection unit 122 detects at least one of the input current and the input voltage of the transmission power supply 12.

  The power supply parameter detection unit 123 detects a parameter related to the inverter circuit 121 in the transmission power supply 12. At this time, the power supply parameter detection unit 123, for example, the resonance voltage of the inverter circuit 121, the resonance current, the phase of the resonance voltage and the resonance current, the reflected power, the voltage Vds or the current between the drain and the source of the switching element in the inverter circuit 121. At least one or more of Ids and heat generation of an element (FET (Field Effect Transistor), capacitor, inductor, etc.) in the inverter circuit 121 is detected.

  The output detection unit 124 detects a parameter related to power output from the transmission power supply 12 (high-frequency power converted by the inverter circuit 121). At this time, the output detection unit 124 detects at least one of the output voltage or output current (phase, amplitude, effective value, frequency) from the inverter circuit 121, transmitted power, reflected power, and the like.

  The input detection unit 122, the power supply parameter detection unit 123, and the output detection unit 124 constitute a parameter detection unit that detects a parameter related to the transmission power supply 12 that changes as the reception-side resonator 21 approaches the transmission-side resonator 13. . And the function of this parameter detection part is realizable by combining the protection function (function for preventing destruction of a power supply) which transmission power supply 12 has normally, and a dedicated circuit is unnecessary. Further, FIG. 1 shows a case where the input detection unit 122, the power supply parameter detection unit 123, and the output detection unit 124 are all included as the parameter detection unit, but at least one of these detection units 122 to 124 is shown. What is necessary is just to have more. Note that the detection accuracy of the resonance condition can be improved by detecting a plurality of parameters.

  The transmission-side resonator 13 resonates at the same frequency as the frequency of the high-frequency power from the transmission power supply 12 and transmits power to the reception-side resonator 21 of the reception device 2.

As illustrated in FIG. 1, the reception device 2 includes a reception-side resonator 21 and a reception circuit 22.
The reception-side resonator 21 receives power by resonating at the same frequency as the resonance frequency of the transmission-side resonator 13 and outputs AC power.

The reception circuit 22 includes a rectifier circuit 221, a DC / DC converter 222, and a load 223.
The rectifier circuit 221 converts AC power from the reception-side resonator 21 into DC power.
The DC / DC converter 222 converts the DC power input from the rectifier circuit 221 into an arbitrary voltage and supplies it to the load 223.
In the receiving circuit 22 shown in FIG. 1, the load 223 may be a battery.

  In addition, the power transmission method based on the resonance coupling between the transmission side resonator 13 and the reception side resonator 21 is not particularly limited, and the magnetic field resonance method, the electric field resonance method, the electromagnetic induction method, and the contact type resonance coupling. Any of the methods may be used.

Next, the configuration of the resonator of the present invention will be described with reference to FIG. In the following description, the transmission-side resonator 13 is taken as an example.
As shown in FIG. 2, the transmission-side resonator 13 includes a transmission coil (power transmission antenna) 131 and a dielectric 132.

  The transmission coil 131 is a coil of a spiral type or a helical type, and the shape thereof may be an arbitrary shape such as a circle, an ellipse, or a rectangle. In the example of FIG. 2, the transmission coil 131 is configured in an elliptical spiral shape.

  The dielectric 132 is disposed so as to face a surface perpendicular to the axial direction of the transmission coil 131, and at least one of the area facing the transmission coil 131 and the distance from the transmission coil 131 is variable. The dielectric 132 is made of ceramic or acrylic. In the example of FIG. 2, a case is shown in which the dielectrics 132 are arranged to face both surfaces of the transmission coil 131. In the example of FIG. 2, a case is shown in which the dielectric 132 is configured to be divided into a plurality of pieces radially about the axis and separable for each piece 1321. In FIG. 2, the dielectric 132 may be composed of a single member or a plurality of members having different dielectric constants.

  In the configuration illustrated in FIG. 2, when the dielectric 132 is configured to have a variable area facing the transmission coil 131, for example, as illustrated in FIG. 3, an arbitrary piece 1321 of the dielectric 132 is parallel to the surface. Move in any direction. Thereby, the parasitic capacitance of the transmission-side resonator 13 can be changed, and the resonance condition can be adjusted.

In the configuration shown in FIG. 2, when the distance between the dielectric 132 and the transmission coil 131 is variable, for example, as shown in FIG. 4, an arbitrary piece 1321 of the dielectric 132 is placed in the plane. Move in a direction perpendicular to. Thereby, the parasitic capacitance of the transmission-side resonator 13 can be changed, and the resonance condition can be adjusted.
Here, the movement of the dielectric 132 as shown in FIGS. 3 and 4 is performed manually. The moving method of the dielectric 132 is appropriately selected according to the installation space of the resonator.

  2 shows the case where the transmission side resonator 13 is provided with the dielectric 132, it is sufficient that at least one of the transmission side resonator 13 and the reception side resonator 21 is provided with the dielectric 132. . The case where the dielectric 132 is provided in the reception-side resonator 21 is configured in the same manner as the case where the dielectric 132 is provided in the transmission-side resonator 13.

Next, an example of adjusting the resonance condition will be described with reference to FIGS. In the following, an example in which the resonance condition is adjusted by moving the dielectric 132 of the transmission-side resonator 13 using the configuration of FIG. 2 will be described.
In FIG. 5, an example of adjusting the resonance condition when the load 223 connected to the reception-side resonator 21 fluctuates or when a foreign object exists between the transmission-side resonator 13 and the reception-side resonator 21. Show. The resonance frequency f ₀ of the resonator in the normal state is expressed by the following expression (1) (solid line in FIG. 5, f ₀ ).
f ₀ = 1 / 2π√ (LC ₀ ) (1)
Here, L is the inductance of the resonator, and C ₀ is the parasitic capacitance of the resonator.

Then, as shown in FIG. 5, when the load 223 connected to the reception-side resonator 21 fluctuates, or when a foreign object exists between the transmission-side resonator 13 and the reception-side resonator 21, the resonator The resonance condition fluctuates (broken line in FIG. 5, f ₁ ). The variation in the resonance condition is obtained from the detection result by the parameter detection unit of the transmission power supply 12.
In this case, the arbitrary piece 1321 of the dielectric 132 of the transmission side resonator 13 shown in FIG. 2 is moved and changed so that the parasitic capacitance of the transmission side resonator 13 is reduced (C0> C1). Thereby, the resonance frequency can be adjusted from f ₁ to f ₀ ′, and the resonance condition can be returned to the initial state (solid line in FIG. 5, f ₀ ′). The resonance frequency f ₀ ′ after adjusting the resonance condition is expressed by the following equation (2).
f ₀ '= 1 / 2π√ (LC ₁ )> f ₁ (2)

FIG. 6 shows an example of adjusting the resonance condition when the distance between the transmission-side resonator 13 and the reception-side resonator 21 is short.
As shown in FIG. 6, when the distance between the transmission-side resonator 13 and the reception-side resonator 21 approaches, the transmission efficiency η on the frequency axis of the resonance condition becomes a bimodal characteristic, and the transmission efficiency η at the resonance frequency f _0. Decreases (broken line in FIG. 6). The variation in the resonance condition is obtained from the detection result by the parameter detection unit of the transmission power supply 12.
In this case, an arbitrary piece 1321 of the dielectric 132 of the transmission side resonator 13 shown in FIG. 2 is moved to change the parasitic capacitance of the transmission side resonator 13. Thereby, the resonance condition can be adjusted so that the transmission efficiency η is high at the resonance frequency f ₁ (solid line in FIG. 6).

  In the present invention, as shown in FIGS. 5 and 6, since the resonance condition can be adjusted by shifting the dielectric 132, it is possible to widen the frequency used in the resonance type power transmission system. .

As described above, according to the first embodiment, at least one of the transmission coil 131 and a reception coil (not shown) (power transmission antenna) is disposed to face the surface perpendicular to the axial direction of the coil. Since the dielectric 132 in which at least one of its own area and the distance between the coil and the coil is variable is provided, the resonance condition of the power transmission antenna can be adjusted and is higher than that of the prior art. It is possible to transmit power even with a voltage and a high current. That is, since the resonance condition can be varied without using an external circuit as in the conventional configuration, there is no restriction due to the rating (voltage, current, etc.) of the elements of the external circuit, and it is easy to increase the power.
In addition, since the resonance condition is adjusted by moving the dielectric 132, the resonance characteristics can be changed continuously instead of discretely. As a result, fine adjustment is possible, and the resonance characteristic can be matched with the target value.

  Although FIG. 2 shows the case where the dielectrics 132 are disposed opposite to both surfaces of the transmission coil 131, they may be provided only on one surface. However, if the dielectric 132 is provided on both sides of the transmission coil 131, the parasitic capacitance can be increased as compared with the case where the dielectric 132 is provided only on one side.

  FIG. 2 shows a case where the area facing the transmission coil 131 is changed by dividing the dielectric 132 into a plurality of pieces and moving the piece 1321 in a direction parallel to the surface. However, the present invention is not limited to this. For example, as shown in FIG. 7, the area facing the transmission coil 131 may be changed by rotating the entire dielectric 132 in the plane. In this case, the transmitting coil 131 and the dielectric 132 are each configured to have a shape in which the facing area changes when the dielectric 132 is rotated.

  FIG. 2 shows the case where the division shape of the dielectric 132 is a radial shape. However, the present invention is not limited to this. For example, a concentric circular shape as shown in FIG. 8 or a quadrangular shape as shown in FIG. 9 may be used.

In FIG. 2, a second dielectric that embeds the transmission coil 131 may be provided. Thereby, the parasitic capacitance of the transmission coil 131 can be further increased.
In FIG. 2, a gap such as a groove or a small hole is provided in the dielectric 132, and a gas (carbon dioxide, nitrogen, etc.), gel, liquid (water, vinegar, etc.) or powdery third is provided inside the dielectric 132. The dielectric may be inserted.

  In FIG. 2, the dielectric 132 may be configured by stacking a plurality of dielectric layers whose relative dielectric constant changes when a voltage is applied. In this case, the transmission-side resonator 13 is further provided with a voltage applying unit that applies a voltage between the dielectric layers constituting the dielectric 132. Thereby, the change of the parasitic capacitance of the transmission coil 131 can be finely adjusted. Further, depending on the installation space of the resonator, the range in which the dielectric 132 can be moved is limited. In this case, the adjustment range of the resonance condition can be expanded by changing the relative dielectric constant.

  In addition, each of the above-described modifications can be similarly applied when the dielectric 132 is provided in the reception-side resonator 21.

  In the above description, the movement of the dielectric 132 has been described on the assumption that it is performed manually, but it may be automated. In this case, for example, as shown in FIG. 10A, a cylinder 5 may be attached to each piece 1321 of the dielectric 132, and the piece 1321 may be moved in a direction parallel to the surface by the cylinder 5. Further, for example, as shown in FIG. 10B, a notched dielectric 132 is used, and the motor 6 is attached to the center of the dielectric 132. Then, the motor 6 may be opened and closed so as to turn the dielectric 132.

  In the above description, the case where the deviation of the resonance condition is detected from the detection result by the parameter detection unit of the transmission power supply 12 is shown. However, the present invention is not limited to this, and any method that can detect the deviation of the resonance condition may be used, and an external circuit that can detect the deviation of the resonance condition may be added to the resonance type power transmission system.

Embodiment 2. FIG.
FIG. 11 is a diagram showing a configuration of a resonator according to the second embodiment of the present invention. The resonator according to the second embodiment shown in FIG. 11 is obtained by adding a magnetic body 133 to the resonator according to the second embodiment shown in FIG. Other configurations are the same, and the same reference numerals are given and description thereof is omitted. In FIG. 11, the transmission side resonator 13 is described as an example.

The magnetic body 133 is disposed opposite to the surface of the transmitting coil 131 opposite to the surface facing the receiving coil. The magnetic body 133 is composed of a member having magnetic permeability such as ferrite or amorphous. The magnetic body 133 may be in the form of a sheet as shown in FIG. 11 or a magnetic paint. Thus, by arranging the magnetic body 133 in the vicinity of the transmission coil 131, the inductance of the transmission-side resonator 13 (L in Expression (1)) is increased, and the resonance condition can be adjusted. Further, by providing the magnetic body 133, an effect of shielding the radiated electromagnetic field from the resonator can be obtained.
As with the dielectric 132, the magnetic body 133 may be divided into a plurality of pieces so as to be separable for each piece.

  In FIG. 11, the case where the dielectric 132 is provided in the transmission-side resonator 13 is shown. However, when the dielectric 132 is provided in the reception-side resonator 21, the magnetic material 133 is provided in the reception-side resonator 21. It may be provided. Note that, when the magnetic body 133 is provided in the reception-side resonator 21, the configuration is the same as in the case where the transmission-side resonator 13 is provided with the magnetic body 133.

  In addition, a temperature control unit that controls the temperature in order to adjust the magnetic permeability by changing the temperature of the magnetic body 133 may be provided in the configuration shown in FIG. Examples of the temperature control unit include a heating wire or a sheet heater. By controlling the temperature of the magnetic body 133 by this temperature control unit, the relative permeability of the magnetic body 133 can be varied and the resonance condition can be adjusted.

Embodiment 3 FIG.
FIG. 11 shows the case where the transmission-side resonator 13 is provided with the magnetic body 133. On the other hand, as shown in FIG. 12, the magnetic body 133 may be configured such that the distance from the opposing transmission coil 131 is variable. Thus, the resonance condition can also be adjusted by making the distance between the magnetic body 133 and the transmission coil 131 variable. In FIG. 12, the transmission-side resonator 13 is described as an example, but the same applies to the case where the reception-side resonator 21 is provided with the magnetic body 133.

  In the first to third embodiments, the case where the resonator of the present invention is applied to a resonant power transmission system as shown in FIG. 1 has been described. However, the present invention is not limited to this, and the resonator of the present invention can be similarly applied to other power transmission systems.

  Further, within the scope of the present invention, the invention of the present application can be freely combined with each embodiment, modified with any component in each embodiment, or omitted with any component in each embodiment. .

  The resonance type power transmission system according to the present invention is capable of adjusting the resonance condition and can transmit power even under a high voltage and high current condition, and includes a transmission side resonator having a transmission coil and a reception coil. This is suitable for use in a resonance type power transmission system that performs power transmission at a specific resonance frequency with a receiving-side resonator having the above.

  DESCRIPTION OF SYMBOLS 1 Transmitter, 2 Receiver, 5 Cylinder, 6 Motor, 11 Primary power supply, 12 Transmission power supply, 13 Transmission side resonator, 21 Reception side resonator, 22 Reception circuit, 121 Inverter circuit, 122 Input detection part, 123 Power supply parameter Detection unit, 124 output detection unit, 131 transmission coil, 132 dielectric, 133 magnetic body, 221 rectifier circuit, 222 DC / DC converter, 223 load, 1321 pieces.

Claims (13)

In a resonant power transmission system that performs power transmission at a specific resonance frequency between a transmission-side resonator having a transmission coil and a reception-side resonator having a reception coil,
At least one of the area of the transmitting coil and the receiving coil that is perpendicular to the axial direction of at least one of the coils and the distance between the coil and the coil is variable. With a dielectric,
The resonant power transmission system, wherein each of the dielectrics is composed of a plurality of members that are separable and have different dielectric constants. In a resonant power transmission system that performs power transmission at a specific resonance frequency between a transmission-side resonator having a transmission coil and a reception-side resonator having a reception coil,
At least one of the area of the transmitting coil and the receiving coil that is perpendicular to the axial direction of at least one of the coils and the distance between the coil and the coil is variable. And a dielectric formed by stacking a plurality of dielectric layers whose relative dielectric constant changes when a voltage is applied;
A resonance type power transmission system, comprising: a voltage application unit that applies a voltage between dielectric layers of the dielectric. In a resonant power transmission system that performs power transmission at a specific resonance frequency between a transmission-side resonator having a transmission coil and a reception-side resonator having a reception coil,
At least one of the area of the transmitting coil and the receiving coil that is perpendicular to the axial direction of at least one of the coils and the distance between the coil and the coil is variable. A dielectric,
A magnetic body disposed opposite to the surface opposite to the surface facing the other coil of the coil;
And a temperature control unit that controls the temperature of the magnetic body. The resonance type power transmission system according to claim 2 or 3 , wherein the dielectric is divided into a plurality of parts so as to be separable. The resonance type power transmission system according to any one of claims 1 to 3 , further comprising a second dielectric body in which the coil is embedded. Other coil in claim 1 or claim 2 resonant power transmission system according to comprising the oppositely disposed magnetic material surface opposite to the facing surface of said coil. The resonant power transmission system according to claim 3 or 6 , wherein the distance between the magnetic body and the coil is variable. The resonant power transmission system according to any one of claims 1 to 3 , wherein the transmission-side resonator and the reception-side resonator perform power transmission by magnetic field resonance. The resonance-type power transmission system according to any one of claims 1 to 3 , wherein the transmission-side resonator and the reception-side resonator perform power transmission by electric field resonance. The resonant power transmission system according to any one of claims 1 to 3 , wherein the transmission-side resonator and the reception-side resonator perform power transmission by electromagnetic induction. In a resonator having a coil that transmits power at a specific resonance frequency with another coil,
A dielectric that is disposed opposite to a surface perpendicular to the axial direction of the coil, and at least one of an area facing the coil and a distance from the coil is variable,
The resonator is composed of a plurality of members that are separable and have different dielectric constants. In a resonator having a coil that transmits power at a specific resonance frequency with another coil,
A dielectric that is disposed opposite to a surface perpendicular to the axial direction of the coil, and at least one of an area facing the coil and a distance from the coil is variable, and a dielectric constant changes when a voltage is applied. A dielectric composed of a plurality of body layers,
And a voltage applying unit that applies a voltage between the dielectric layers of the dielectric. In a resonator having a coil that transmits power at a specific resonance frequency with another coil,
A dielectric disposed opposite to a surface perpendicular to the axial direction of the coil, wherein at least one of an area facing the coil and a distance from the coil is variable;
A magnetic body disposed opposite to the surface opposite to the surface facing the other coil of the coil;
And a temperature control unit for controlling the temperature of the magnetic body.

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