JP6164720B2 - Coupled resonator type wireless power transmission system - Google Patents

Description

The present invention relates to a wireless power transmission system of the resonator type which performs power transmission by radio using a coupling between the resonators with non radiation field.

  2. Description of the Related Art In recent years, a coupled resonator type wireless power transmission system has attracted a great deal of attention because highly efficient power transmission is possible even if there is a certain distance from a power transmission side resonator to a power reception side resonator.

  Various proposals have been made so far for the coupled resonator type wireless power transmission system. For example, Patent Document 1 describes a basic configuration of a wireless power transmission system that performs power transmission by causing resonance in a resonator such as a loop conductor provided on both the transmission side and the reception side. ing. In Patent Literature 2, in a wireless power transmission system that performs power transmission by causing resonance between a coil of a power transmission side resonator and a coil of a power reception side resonator, a distance between the power transmission side resonator and the power reception side resonator is set. What detects and changes the resonance frequency based on it is described.

Special table 2009-501510 JP 2010-239769 A

  By the way, there is usually an object or a person between the power transmission side resonator and the power reception side resonator. Objects and people behave almost as dielectrics, and the characteristics (electromagnetic characteristics) of the space between the power transmission resonator and the power reception resonator are affected by the dielectric. When the dielectric or the power-receiving-side resonator moves, the space between the power-transmission-side resonator and the power-receiving-side resonator due to the presence or absence of the dielectric or a change in the position, or due to a change in the position of the power-receiving-side resonator. The characteristics of change with time. Due to the change, the resonance frequencies of the power transmission side resonator and the power reception side resonator are changed, and the transmission efficiency is easily lowered.

  However, the coupled resonator type wireless power transmission system conventionally proposed including Patent Documents 1 and 2 does not consider the influence of the dielectric between the power transmission side resonator and the power reception side resonator. Many.

The present invention has been made in view of the above-described reason, and the purpose thereof is a coupled resonance that is less affected by a dielectric between the power transmission side resonator and the power reception side resonator and can suppress a decrease in power transmission efficiency. and to provide a vessel-type wireless power transmission system of.

In order to achieve the above object, a coupled resonator type wireless power transmission system according to claim 1 is configured to include a first coil, a second coil, and a capacitor. The coil and the second coil are spiral coils and are arranged close to each other so that the electric field strength between them is large due to capacitive coupling, and the electric field strength outside them is small. One of both ends of the coil and one of both ends of the second coil are connected to the other one of both ends of the first coil and both ends of the second coil via the capacitor. not through other one of the capacitors, respectively connected, however, the inner end of the inner end and the second coil of the first coil was divided to be connected without passing through the condenser, at least one Power transmission resonator and at least one power transmission A controller that controls excitation of one power transmission side resonator of the resonators, and is disposed outside the two coils of the one power transmission side resonator and is transmitted from the one power transmission side resonator. A power-receiving-side resonator that receives power.

According to the wireless power transmission system of the resonator type according to the present invention, it is possible to reduce the electric field strength outside of the coils of the power transmission resonator, the power transmitting side resonator and the power receiving side resonator The influence of the dielectric between them is small, and it is possible to suppress the reduction of the power transmission efficiency.

1 is a block diagram of a configuration of a coupled resonator type wireless power transmission system according to an embodiment of the present invention. FIG. 1 shows one power transmission side resonator of the above-described coupled resonator type wireless power transmission system, wherein (a) is a wiring diagram of one power transmission side resonator and a controller, and (b) is one power transmission side resonator. (C) is a schematic side view of two coils. It is a wiring diagram which shows two cases of the modification of the wiring of the power transmission side resonator of one of the same coupling resonator type wireless power transmission systems. The other power transmission side resonator of a coupling resonator type radio | wireless power transmission system same as the above is shown, (a) is a wiring diagram of another power transmission side resonator, (b) comprises another power transmission side resonator. The schematic front view of a coil and (c) are schematic side views of two coils. It is a wiring diagram which shows the modification of the wiring of the power transmission side resonator of one coupling | bonding resonator type wireless power transmission system same as the above, and a controller. FIG. 2 is an enlarged view of a power receiving side resonator of the above-described coupled resonator type wireless power transmission system, where (a) is a wiring diagram of a power receiving side resonator and a load circuit, and (b) is a power receiving side resonator. The schematic front view of a coil and (c) are schematic side views of two coils. It is a wiring diagram which shows the modification of the wiring of a receiving side resonator and load circuit of a coupling resonator type wireless power transmission system same as the above. The odd-mode electric field distribution and magnetic field distribution of the coupling resonator type wireless power transmission system are shown, wherein (a) is a simplified waveform diagram of the electric field distribution and (b) is the magnetic field distribution. It is a characteristic view which shows the change of the inductance value and the capacitance value with respect to the number of coil turns of the power transmission side resonator of the wireless power transmission system of the coupled resonator type same as the above. 2 shows the electric field strength and magnetic field strength between one power transmission side resonator and another power transmission side resonator of the coupled resonator type wireless power transmission system of the above, where (a) shows the electric field strength and (b) shows the magnetic field. It is a characteristic view of strength. It is another characteristic figure which shows the electric field strength between one power transmission side resonator of the coupling resonator type wireless power transmission system same as the above, and another power transmission side resonator. It is a schematic diagram which shows the structure of the simulation and experiment of the resonant frequency shift amount of a coupling resonator type wireless power transmission system same as the above. It is a characteristic view which shows the result of the simulation using the structure of FIG. It is a characteristic view which shows the result of the experiment by the actual sample using the structure of FIG. It is another characteristic view which shows the result of the experiment by the actual sample using the structure of FIG. It is a schematic diagram which shows the structure of the experiment of the receiving side resonator of a coupling resonator type wireless power transmission system same as the above. It is a characteristic view which shows the result of the experiment by the actual sample using the structure of FIG. It is another characteristic view which shows the result of the experiment by the actual sample using the structure of FIG. It is a schematic diagram which shows the structure of the experiment of the whole coupling resonator type wireless power transmission system same as the above. It is a characteristic view which shows the result of the experiment by the actual sample using the structure of FIG. It is a block diagram which shows the modification of a coupling resonator type wireless power transmission system same as the above.

    Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. As shown in FIG. 1, a coupled resonator type wireless power transmission system 1 according to an embodiment of the present invention includes two power transmission side resonators, that is, one power transmission side resonator 2 and another power transmission side resonator 3. And a controller 4, one power-receiving-side resonator 5, and a load circuit 6.

  As shown in FIG. 2A, one power transmission side resonator 2 includes two coils (first coil 21 and second coil 22) and a capacitor 23 that are arranged close to each other. It is configured. Both coils 21 and 22 are arranged such that a magnetic field in the same direction is generated. The coils 21 and 22 may have substantially the same number of turns and the same size, but the number of turns or the sizes may be different. Moreover, as shown in FIG.2 (b), both the coils 21 and 22 can be made into the coil formed by winding an electrical conductor planarly and spirally, ie, a spiral coil. In this case, as shown in FIG. 2 (c), the coils 21 and 22 are arranged substantially parallel to each other with a predetermined distance A, and are arranged so that the central axes (z-axis) of the spirals are substantially coincident with each other. .

  Regarding the connection of the first coil 21 and the second coil 22, one of both ends of the first coil 21 and one of both ends of the second coil 22 are connected via the capacitor 23 to the first coil. The other one of the two ends of 21 and the other one of the two ends of the second coil 22 are electrically connected without a capacitor. More specifically, as shown in FIG. 2 (a), the first coil 21 and the second coil 22 are wound in the same direction in which the electric conducting wires are wound, and the one end 21a of the first coil 21 and the second coil The other end 22b of the coil 22 is connected via a capacitor 23, and the other end 21b of the first coil 21 and one end 22a of the second coil 22 are connected via no capacitor. Alternatively, as shown in FIG. 3A, the one end 21a of the first coil 21 and the other end 22b of the second coil 22 are not connected to the other end 21b of the first coil 21 and the second It is also possible to connect the one ends 22a of the coils 22 via the capacitors 23, respectively. Alternatively, as shown in FIG. 3 (b), one end 21a of the first coil 21 and the second coil are reversed by reversing the direction in which the electric conductors of the first coil 21 and the second coil 22 are wound. It is also possible to connect one end 22a of 22 via the capacitor 23 and the other end 21b of the first coil 21 and the other end 22b of the second coil 22 without passing through the capacitor. Alternatively, although not shown, other connection methods of the first coil 21 and the second coil 22 are possible.

  Other power transmission side resonators 3 have the same configuration as that of one power transmission side resonator 2. That is, as shown in FIG. 4A, the other power transmission side resonator 3 has two coils (first coil 31 and second coil 32) arranged close to each other and a capacitor 33. Configured. Both coils 31 and 32 are arranged so that a magnetic field in the same direction is generated. The coils 31 and 32 may have substantially the same number of turns and the same size. Moreover, both the coils 31 and 32 can be made into a spiral coil as shown in FIG.4 (b). In this case, as shown in FIG. 4C, the coils 31 and 32 are arranged substantially parallel to each other with a predetermined distance A ′, and are arranged so that the center axis (z axis) of the spiral substantially coincides. The Regarding the connection of the first coil 31 and the second coil 32, one of both ends of the first coil 31 and one of both ends of the second coil 32 are connected via the capacitor 33 to the first coil 31. The other one of both ends of 31 and the other one of both ends of the second coil 32 are electrically connected without a capacitor. About the specific connection method of the 1st coil 31 and the 2nd coil 32, the several connection method similar to the case of the 1st coil 21 and the 2nd coil 22 of said one power transmission side resonator 2 is mentioned. Is possible.

  One power transmission side resonator 2 and the other power transmission side resonator 3 are arranged to face each other with a predetermined distance B so that their central axes substantially coincide.

  The controller 4 controls excitation of one power transmission side resonator 2. Specifically, the controller 4 includes a high-frequency power supply 41 and a coupling loop 42 as shown in FIGS. 1 and 2A. The high frequency power supply 41 excites one power transmission side resonator 2 through a coupling loop 42 that performs impedance matching. That is, the high frequency power supply 41 outputs the output signal to the coupling loop 42, and the coupling loop 42 is electromagnetically coupled to one power transmission side resonator 2. The coupling loop 42 can be replaced by other known impedance matching means. In addition, as shown in FIG. 5, the output terminal of the high frequency power supply 41 is electrically connected directly to the circuit of one power transmission side resonator 2, and the number of turns of both the coils 21, 22 and the capacitance value of the capacitor 23 are adjusted. In some cases, impedance matching means such as the coupling loop 42 can be omitted by performing impedance matching.

  The other power transmission side resonator 3 is not excited by the controller 4 or another controller, but is excited by receiving an electromagnetic field generated by one power transmission side resonator 2 as described later.

  The power receiving side resonator 5 is usually smaller than the two power transmitting side resonators 2 and 3, but has the same configuration as the two power transmitting side resonators 2 and 3. That is, the power-receiving-side resonator 5 includes two coils (a first coil 51 and a second coil 52) and a capacitor 53 that are arranged close to each other as shown in FIG. It is configured. Both coils 51 and 52 are arranged so that a magnetic field in the same direction is generated. The coils 51 and 52 may have substantially the same number of turns and the same size. Moreover, both the coils 51 and 52 can be made into a spiral coil as shown in FIG.6 (b). In this case, as shown in FIG. 6C, the two coils 51 and 52 are arranged so as to be separated from each other by a predetermined distance A ″ and substantially parallel to each other, and are arranged so that the central axes of the spirals are substantially coincident with each other. Regarding the connection between the first coil 51 and the second coil 52, one of both ends of the first coil 51 and one of both ends of the second coil 52 are connected via the capacitor 23 to the first coil. The other one of both ends of 51 and the other one of both ends of the second coil 52 are electrically connected without a capacitor. About the specific connection method of the 1st coil 51 and the 2nd coil 52, several connection methods similar to the case of the 1st coil 21 and the 2nd coil 22 of said one power transmission side resonator 2 are mentioned. Is possible.

  The power receiving side resonator 5 includes the power transmitting side resonator 2 and the power transmitting side outside the two coils 21 and 22 of one power transmitting side resonator 2 and the outside of both coils 31 and 32 of the other power transmitting side resonator 3. It is arrange | positioned between the resonators 3 and receives the electric power transmitted from the power transmission side resonator 2 and the power transmission side resonator 3. FIG. The distance between the power receiving side resonator 5 and the one power transmitting side resonator 2 and the distance between the power receiving side resonator 5 and the other power transmitting side resonator 3 are the two coils 21 and 22 of the one power transmitting side resonator 2. Than the distance A ′ between the coils 31 and 32 of the other power transmission side resonator 3 and the distance A ″) between the coils 51 and 52 of the power reception side resonator 5. Big. The power receiving resonator 5 can be moved.

  A load circuit 6 is coupled to the power receiving side resonator 5. Specifically, the load circuit 6 includes a coupling loop 61 and a load 62. The coupling loop 61 is electromagnetically coupled to the power receiving resonator 3 and performs impedance matching. As will be described later, the power transmitted from one power transmission side resonator 2 and another power transmission side resonator 3 to the power reception side resonator 5 is supplied to the load 62 via the coupling loop 61. The load 62 is a circuit for a required function of the device such as a charging circuit of a portable device in the communication field and a power supply circuit of a self-propelled microcapsule in the body in the medical field. The coupling loop 61 can be replaced with other known impedance matching means. Further, as shown in FIG. 7, the input terminal of the load 62 is electrically connected directly to the circuit of the power receiving resonator 2, and the impedance matching is performed by adjusting the number of turns of the coils 51 and 52 and the capacitance value of the capacitor 53. In some cases, impedance matching means such as the coupling loop 61 can be omitted.

  In the coupled resonator type wireless power transmission system 1 having such a configuration, one power transmission side resonator 2 excited by the controller 4 has an electromagnetic field (non-radiated electromagnetic wave) in a surrounding region (particularly in the direction of the central axis). ). Then, the other power transmission side resonator 3 is excited by being coupled to the electromagnetic field generated by one power transmission side resonator 2. The other power transmission side resonators 3 also generate an electromagnetic field in the surrounding area (particularly in the direction of the central axis). Thereby, the electromagnetic field distributed between one power transmission side resonator 2 and another power transmission side resonator 3 is generated by the electromagnetic field generated by one power transmission side resonator 2 and the other power transmission side resonator 3. An electromagnetic field is synthesized.

  An electromagnetic field distributed by a plurality of resonators such as one power transmission side resonator 2 and another power transmission side resonator 3 has a plurality of resonance modes, and the frequency corresponding to each of these resonance modes is a little. A plurality of resonance frequencies different from each other are generated. The electromagnetic field distributed by one power transmission resonator 2 and another power transmission resonator 3 is in phase with an odd mode in which the electric fields of one power transmission resonator 2 and other power transmission resonator 3 resonate in opposite phases. It has an even mode that resonates. The odd-mode resonance frequency is lower than the even-mode resonance frequency.

  The odd-mode electric field distribution E1 is approximately the sum of the electric field distribution E2 from one power transmission side resonator 2 and the electric field distribution E3 from another power transmission resonator 3 alone, and one power transmission side Since the electric fields of the resonator 2 and the other power transmission side resonator 3 are in opposite phases, as shown in FIG. 8A, the electric field is zero at the center of one power transmission side resonator 2 and the other power transmission side resonator 3. Half of the area has a positive value, and the other half has a negative value. The odd-mode magnetic field distribution H1 is approximately the sum of the magnetic field distribution H2 from one power transmission side resonator 2 and the magnetic field distribution H3 from another power transmission side resonator 3, and one power transmission side resonance. Since the magnetic fields of the power transmitter 2 and the other power transmission side resonator 3 are in phase, as shown in FIG. 8B, the strength slightly decreases at the center of one power transmission side resonator 2 and the other power transmission side resonator 3. However, there is little change from one power transmission side resonator 2 to another power transmission side resonator 3.

  The power receiving resonator 5 disposed between one power transmitting resonator 2 and another power transmitting resonator 3 is an electromagnetic field distributed by the one power transmitting resonator 2 and the other power transmitting resonator 3. Are coupled and resonated, whereby electric power transmission is performed from one power transmission side resonator 2 and another power transmission side resonator 3. It is the magnetic field that mainly affects the coupling between the resonators by this electromagnetic field.

  Therefore, when the coupled resonator type wireless power transmission system 1 is configured using the odd mode, there is less dependence on the location between the one power transmission side resonator 2 and the other power transmission side resonator 3, and at a low frequency. Power transmission becomes possible.

  Next, the two coils 21 and 22 are arranged close to each other to form one power transmission side resonator 2, and the two coils 31 and 32 are arranged close to each other to form another power transmission side resonator 3. The effect of electric field confinement will be described.

  If a dielectric exists at any location between one power transmission resonator 2 and another power transmission resonator 3, the electric field is more susceptible than the magnetic field. When the electric field is affected, the resonance frequency of one power transmission side resonator 2 and the other power transmission side resonator 3 is shifted, and the power reception side resonator 5 is shifted from the one power transmission side resonator 2 and the other power transmission side resonator 3. The transmission efficiency of power to the power source will be reduced.

  Between the first coil 21 and the second coil 22 arranged close to each other on the one power transmission side resonator 2, the electric field strength is large due to capacitive coupling, and therefore, the electric field strength is small outside the two coils 21 and 22. . The magnetic field intensity outside the two coils 21 and 22 is not much different from the case of a single coil having the total number of turns of the two coils 21 and 22. The same applies to the other power transmission side resonators 3. In this way, electric field confinement occurs inside one power transmission resonator 2 and another power transmission resonator 3.

  Accordingly, since the electric field strength between the outer side of the coils 21 and 22 and the outer side of the coils 31 and 32 and the other transmitting side resonator 3 is small, the receiving side resonance is reduced. Even if there is a dielectric between the power transmitter 5 and the one power transmission side resonator 2 or between the power reception side resonator 5 and the other power transmission side resonator 3, the influence is small. It is possible to suppress a decrease in transmission efficiency of power from one power transmission side resonator 2 and another power transmission side resonator 3 to the power reception side resonator 5 due to a shift in the resonance frequency of the power transmission side resonator 3. it can.

  Next, the effect of electric field confinement by configuring the power receiving resonator 5 by arranging the first coil 51 and the second coil 52 close to each other will be described.

  In the power receiving side resonator 5, when a dielectric is present around the power receiving side resonator 5, the electric field is more susceptible than the magnetic field. When the electric field is affected, the resonance frequency of the power receiving resonator 5 is shifted, and the power transmission efficiency from one power transmitting resonator 2 and another power transmitting resonator 3 to the power receiving resonator 5 is reduced. become.

  When the power receiving resonator 5 resonates, the electric field strength between the first coil 51 and the second coil 52 arranged close to the power receiving resonator 5 is large due to capacitive coupling. Outside, the strength of the electric field generated by the power receiving resonator 5 is reduced. The strength of the magnetic field generated by the power-receiving-side resonator 5 outside the two coils 51 and 52 is not much different from that of the single coil having the total number of turns of the two coils 21 and 22. Thus, the electric field is confined inside the power receiving resonator 5.

  Accordingly, since the electric field strength generated by the power receiving resonator 5 outside the coils 51 and 52 of the power receiving resonator 5 is small, the power receiving resonator 5 and one power transmitting resonator 2 or the power receiving Even if there is a dielectric between the side resonator 5 and the other power transmission side resonator 3, the influence of the dielectric around the power reception side resonator 5 is small, and the resonance frequency of the power reception side resonator 5 is shifted to one. The power transmission efficiency from the power transmission side resonator 2 and the other power transmission side resonator 3 to the power reception side resonator 5 can be reduced.

  Next, simulations of one power transmission side resonator 2 and another power transmission side resonator 3 conducted by the inventors of the present application and experiments using actual samples will be described.

  Excitation of one power transmission side resonator 2 inputs 1 W of power, and does not depend on the number of turns of the first coil 21 and the second coil 22 so that the reflection coefficient S11 is always −1 dB. The arrangement and the like are adjusted so that the same amount of power is transmitted to one power transmission resonator 2. The coils 21 and 22 of one power transmission side resonator and the coils 31 and 32 of the other power transmission side resonator 3 have a diameter of 30 cm. The distance B between one power transmission resonator 2 and another power transmission resonator 3 was 20 cm. The central axis of one power transmission side resonator 2 and the other power transmission side resonator 3 is taken as the Z axis, and the position of the center is set as the coordinate value 0. The resonance uses the odd mode described above, and the resonance frequency is 1 MHz. Further, when the number of turns of both the coils 21 and 22 of one power transmission side resonator 2 and the coils 31 and 32 of the other power transmission side resonator 3 is changed, their inductance values are changed to a curve a in FIG. Therefore, in order to match the resonance frequency, the capacitance values of the capacitor 23 and the capacitor 33 were changed as shown by a curve b in FIG.

  FIG. 10A shows the electric field strength on the central axis (z-axis) between one power transmission resonator 2 and another power transmission resonator 3 by simulation, and FIG. 10B shows the magnetic field strength. WIPL-D was used as the simulation software. The electric field intensity shown in FIG. 10A is an absolute value display, and the negative value is changed to a positive value. The same display is performed also in all the figures showing the electric field strength described later. A curve c1 in FIG. 10A and a curve e1 in FIG. 10B indicate the total number of turns of both coils 21 and 22 of one power transmission side resonator 2 and both coils 31 and 32 of the other power transmission side resonator 3. The characteristic of the total number of turns of 15 is shown. A curve c2 in FIG. 10A and a curve e2 in FIG. 10B indicate the total number of turns of both coils 21 and 22 of one power transmission side resonator 2 and both coils 31 and 32 of the other power transmission side resonator 3. The characteristic of the total number of turns of 25 is shown. At this time, the distance A between the two coils 21 and 22 of one power transmission side resonator 2 and the distance A 'between the coils 31 and 32 of the other power transmission side resonator 3 are 2 mm. Curves d1 and d2 in FIG. 10 (a) and curves f1 and f2 in FIG. 10 (b) are comparative examples, and one power transmission side resonator 2 and the other power transmission side resonator 3 are each composed of a single coil. It shows the characteristics of what was constructed. Curves d1 and f1 show the characteristics of a single power transmission side resonator 2 having a single coil winding number and another power transmission side resonator 3 having a single coil winding number of 15. Curves d2 and f2 show the characteristics of a single power transmission side resonator 2 having a single coil winding number and another power transmission side resonator 3 having a single coil winding number of 25.

  When the curve c1 and the curve d1 and the curve c2 and the curve d2 in FIG. 10A are compared, one power transmission side resonator 2 is configured by both the coils 21, 22, and the other power transmission side resonator 3 is configured by the two coils 31, The electric field strength is smaller in the configuration of 32 than in the case where one power transmission side resonator 2 and the other power transmission side resonator 3 are each configured by a single coil. On the other hand, when the curve e1 and the curve f1 and the curve e2 and the curve f2 in FIG. 10B are compared, one power transmission side resonator 2 is composed of both coils 21 and 22, and the other power transmission side resonator 3 is composed of both coils. The magnetic field strength is larger in the configuration of 31 and 32 than in the case where one power transmission side resonator 2 and the other power transmission side resonator 3 are each configured by a single coil. Thus, when one power transmission side resonator 2 is constituted by both coils 21 and 22 and another power transmission side resonator 3 is constituted by both coils 31 and 32, one power transmission side resonator 2 and another power transmission side resonance are formed. It can be seen that the electric field is confined inside the device 3, and the electric field strength between one power transmission side resonator 2 and the other power transmission side resonator 3 is reduced, while the magnetic field strength is not reduced.

  Further, when the curve c1 and the curve c2 in FIG. 10A are compared and the curve e1 and the curve e2 in FIG. 10B are compared, the smaller the total number of turns, the smaller the electric field strength and the smaller the magnetic field strength. .

  One power transmission side resonator 2 when the distance A between the coils 21 and 22 of one power transmission side resonator 2 and the distance A ′ between the coils 31 and 32 of the other power transmission side resonator 3 are changed. FIG. 11 shows the electric field strength on the central axis (z-axis) between the power transmission side resonator 3 and other power transmission side resonators 3. Curves g1, g2, g3, and g4 indicate that the distance A ′ between the coils 21 and 22 of one power transmission side resonator 2 and the distance A ′ between the coils 31 and 32 of the other power transmission side resonator 3, respectively. The characteristics when 1 mm, 2 mm, 5 mm, and 10 mm are shown. At this time, the total number of turns of both coils 21 and 22 of one power transmission side resonator and the total number of turns of both coils 31 and 32 of the other power transmission side resonator 3 are set to 15 times. According to FIG. 11, the shorter the distance A ′ between the coils 21 and 22 of one power transmission resonator 2 and the distance A ′ between the coils 31 and 32 of the other power transmission resonator 3, the shorter the electric field strength. There is a tendency to become smaller. From this, it is more effective to shorten the distance A ′ between the coils 21 and 22 of one power transmission resonator 2 and the distance A ′ between the coils 31 and 32 of the other power transmission resonator 3. It can be seen that the confinement can be increased. In addition, although illustration is abbreviate | omitted regarding a magnetic field, the mutual distance A of both the coils 21 and 22 of the one power transmission side resonator 2 and the mutual distance A 'of both the coils 31 and 32 of the other power transmission side resonator 3 are shown. There was almost no difference even when changing.

  Next, another simulation performed by the inventors of the present invention regarding one power transmission resonator 2 and another power transmission resonator 3 will be described. As shown in FIG. 12, between the one power transmission side resonator 2 and the other power transmission side resonator 3, the one power transmission side resonator 2 and the other when the dielectric 7 is not disposed are disposed. The shift amount of the resonance frequency of the power transmission side resonator 3 was calculated. The dielectric 7 has a size of 18 cm in the central axis direction and 10 cm in the direction perpendicular to the central axis direction. A curve h in FIG. 13 indicates that the total number of turns of both the coils 21 and 22 of one power transmission side resonator 2 and the total number of turns of both the coils 31 and 32 of the other power transmission side resonator 3 is 15 times. The distance A ′ between the coils 21 and 22 of the side resonator 2 and the distance A ′ between the coils 31 and 32 of the other power transmission side resonator 3 are set to 2 mm. The characteristic of quantity dependence is shown. A curve i is a comparative example, and one power transmission side resonator 2 and another power transmission side resonator 3 are each configured by a single coil, and the dependency of the resonance frequency shift amount on the dielectric constant of the dielectric 7 is shown. The characteristics are shown.

  Comparing curve h and curve i, one power transmission side resonator 2 is composed of both coils 21 and 22, and the other power transmission side resonator 3 is composed of both coils 31 and 32. The amount of shift of the resonance frequency is smaller than that in which the resonator 2 and the other power transmission side resonator 3 are each constituted by a single coil. From this, one power transmission side resonator 2 is comprised by both the coils 21 and 22, and the other power transmission side resonator 3 is comprised by both the coils 31 and 32, Therefore One power transmission side resonator 2 and other power transmission are comprised. Even if the dielectric constant of the dielectric changes between the side resonators 3, that is, the state of the presence or position of the dielectric changes, the resonance frequency of one power transmission side resonator 2 and the other power transmission side resonator 3 It can be seen that the shift is suppressed.

  Next, an experiment of one power transmission side resonator 2 and another power transmission side resonator 3 using an actual sample performed by the present inventor will be described. When a plastic container containing water is disposed as the dielectric 7 between the one power transmission resonator 2 and the other power transmission resonator 3 as shown in FIG. The shift amount of the resonance frequency of one power transmission side resonator 2 and the other power transmission side resonator 3 was measured. Curves j1, j2, and j3 in FIG. 14 each have a total number of turns of both coils 21 and 22 of one power transmission side resonator 2 and a total number of turns of both coils 31 and 32 of another power transmission side resonator 3. For the five times, the 15 times, and the 22 times, the distance A between the coils 21 and 22 of one power transmission side resonator 2 and the mutual coils 31 and 32 of the other power transmission side resonator 3 The dependence characteristic of the shift amount of the resonance frequency with respect to the distance A ′ is shown. In each of the curves j1, j2, and j3, the distance A ′ between the coils 21 and 22 of one power transmission side resonator 2 and the distance A ′ between the coils 31 and 32 of the other power transmission side resonator 3 are 0. The value at this time indicates the case where one power transmission side resonator 2 and the other power transmission side resonator 3 are each configured by a single coil.

  According to FIG. 14, one power transmission side resonator 2 is composed of both coils 21 and 22, and the other power transmission side resonator 3 is composed of both coils 31 and 32. The amount of shift of the resonance frequency is smaller than that in the case where each of the power transmission side resonators 3 is composed of a single coil. From this, one power transmission side resonator 2 is comprised by both the coils 21 and 22, and the other power transmission side resonator 3 is comprised by both the coils 31 and 32, Therefore One power transmission side resonator 2 and other power transmission are comprised. It can be seen that the shift of the resonance frequency of one power transmission side resonator 2 and the other power transmission side resonator 3 due to the presence or absence of a dielectric between the side resonators 3 is suppressed.

  Further, the shorter the distance A between the coils 21 and 22 of one power transmission resonator 2 and the distance A ′ between the coils 31 and 32 of the other power transmission resonator 3, the more the resonance frequency shift amount becomes. As the number of turns decreases and the number of turns decreases, the shift amount of the resonance frequency tends to decrease.

  FIG. 15 shows the measured value of the no-load Q value. This is to show that the unloaded Q value does not decrease by configuring one power transmission side resonator 2 with both coils 21 and 22 and configuring the other power transmission side resonator 3 with both coils 31 and 32. belongs to. In the curves k1, k2, and k3 in FIG. 15, the total number of turns of both coils 21 and 22 of one power transmission side resonator 2 and the total number of turns of both coils 31 and 32 of the other power transmission side resonator 3 are 7. For the five times, the 15 times, and the 22 times, the distance A between the coils 21 and 22 of one power transmission side resonator 2 and the mutual coils 31 and 32 of the other power transmission side resonator 3 The characteristic of the dependence of the unloaded Q value on the distance A ′ is shown. In each of the curves k1, k2, and k3, the mutual distance A between the coils 21 and 22 of one power transmission side resonator 2 and the mutual distance A ′ of both coils 31 and 32 of the other power transmission side resonator 3 are 0. The value at this time indicates the case where one power transmission side resonator 2 and the other power transmission side resonator 3 are each configured by a single coil. According to FIG. 15, one power transmission side resonator 2 is composed of both coils 21 and 22, and the other power transmission side resonator 3 is composed of both coils 31 and 32. The no-load Q value is better than each of the power transmission side resonators 3 configured by a single coil. When the distance A between the coils 21 and 22 of one power transmission resonator 2 and the distance A ′ between the coils 31 and 32 of the other power transmission resonator 3 are changed, the no-load Q value is slightly changed. The unloaded Q value tends to improve as the number of turns increases.

  Next, an experiment of the power-receiving-side resonator 5 using an actual sample conducted by the present inventor will be described. Both the coils 51 and 52 of the power receiving resonator 5 have a diameter of 3 cm. The resonance frequency was 1 MHz. Further, when the number of turns of both the coils 51 and 52 of the power receiving resonator 5 was changed, the capacitance value of the capacitor 53 was changed in order to match the resonance frequency.

  As shown in FIG. 16, on both sides of the power receiving side resonator 5, when the plastic containers 7A and 7B containing water as a dielectric are arranged, and the resonance frequency of the power receiving side resonator 5 with respect to when the plastic containers 7A and 7B are not arranged, The amount of shift was measured. The plastic containers 7A and 7B containing water have a size of 9 cm in the central axis direction and 10 cm in a direction perpendicular to the central axis direction. Curves m1, m2, and m3 in FIG. 17 respectively indicate that the total number of turns of the coils 51 and 52 of the power receiving side resonator 5 is 4, 8, and 15 times. The characteristic of the dependence of the shift amount of the resonance frequency with respect to the mutual distance A ″ of both the coils 51 and 52 is shown. In each of the curves m1, m2, and m3, when the distance A ″ between the coils 51 and 52 of the power receiving resonator 5 is 0, the power receiving resonator 5 is composed of a single coil. The thing when a thing is used is shown.

  According to FIG. 17, when the power receiving side resonator 5 is configured such that the distance A ″ between the coils 51 and 52 is about 1 mm, the resonance frequency shift amount is larger than that of the power receiving side resonator 5 formed of a single coil. Is decreasing. Thus, by configuring the power receiving side resonator 5 with both the coils 51 and 52, it is possible to suppress a shift in the resonance frequency of the power receiving side resonator 5 due to the presence or absence of a dielectric around the power receiving side resonator 5. I understand.

  In addition, the resonance frequency shift amount decreases as the distance A ″ between the coils 51 and 52 of the power transmission / reception resonator 5 decreases, and the resonance frequency shift amount tends to decrease as the number of turns increases. .

  FIG. 18 shows the measured value of the no-load Q value. This is to show that the unloaded Q value does not decrease by configuring the power receiving side resonator 5 with both the coils 51 and 52. Curves n1, n2, and n3 in FIG. 18 respectively indicate that the total number of windings of both coils 51 and 52 of the power receiving resonator 5 is 4, 8, and 15 times. The characteristic of the dependence of the no-load Q value with respect to the mutual distance A ″ of both the coils 51 and 52 is shown. In each of the curves n1, n2, and n3, when the distance A ″ between the coils 51 and 52 of the power receiving resonator 5 is 0, the power receiving resonator 5 is composed of a single coil. It is a thing when using a thing. According to FIG. 18, the unloaded Q value is better when the power receiving side resonator 5 is composed of both coils 51 and 52 than when the power receiving side resonator 5 is composed of a single coil. Further, even if the distance A ″ between the coils 51 and 52 of the power-receiving-side resonator 5 is changed, the unloaded Q value hardly changes, and the unloaded Q value tends to improve as the number of turns increases. .

  Next, an experiment of the coupled resonator type wireless power transmission system 1 as a whole using an actual sample performed by the present inventor will be described. Here, the total number of turns of both coils 21 and 22 of one power transmission side resonator 2 and the total number of turns of both coils 31 and 32 of another power transmission side resonator 3 are set to 15 times, and one power transmission side resonator 2 is obtained. The distance A between the coils 21 and 22 and the distance A ′ between the coils 31 and 32 of the other power transmission resonator 3 are 2 mm, and the total number of turns of the coils 51 and 52 of the power reception resonator 5 is 2 mm. The distance A ″ between the coils 51 and 52 of the power receiving resonator 5 was set to 1 mm. The measurement was performed at the center between one power transmission side resonator 2 and another power transmission side resonator 3, that is, at a location where the coordinate value of the central axis (z axis) is zero.

  Between one power transmission resonator 2 and another power transmission resonator 3, plastic containers 7A and 7B containing water as dielectrics 7 are arranged on both sides of the power reception resonator 5 as shown in FIG. The frequency dependence of the transmission efficiency S21 at this time is shown by a curve o in FIG. A curve p shows the frequency dependence of the transmission efficiency S21 when the plastic containers 7A and 7B are not arranged. The curve o and the curve p almost overlap, and it can be seen that the dielectric 7 has little influence on the transmission efficiency S21.

  As described above, according to the coupled resonator type wireless power transmission system 1 based on the simulation performed by the inventors of the present application and the experiment using the actual sample, the power receiving side resonator 5 and the power transmitting side resonance are one. Even if a dielectric exists between the power receivers 2 or between the power receiving resonator 5 and the other power transmitting resonator 3, it can be seen that the influence of the dielectric is small and the reduction in transmission efficiency can be suppressed. .

  The wireless power transmission system according to the embodiment of the present invention has been described above. However, the present invention is not limited to that described in the above-described embodiment, and various modifications within the scope of the matters described in the claims. Design changes are possible. For example, when the configuration of the coupled resonator type wireless power transmission system 1 is simplified, as illustrated in FIG. 21, the coupled resonator type wireless power transmission system 1 ′ in which the other power transmission side resonator 3 is omitted is illustrated. It is also possible to deform it. In this case, the magnetic field changes relatively as shown in the magnetic field distribution H2 shown in FIG. 8B, but the electric field strength outside the coils 21 and 22 of one power transmission resonator 2 is small. Therefore, when power is transmitted to the power receiving resonator 5 disposed outside the two coils 21 and 22 of the one power transmitting resonator 2, the power receiving resonator 5 and the one power transmitting resonator 2 are connected. Even if a dielectric is present in the dielectric, its influence is small, the resonance frequency of one power transmission resonator 2 is shifted, and the power transmission efficiency from one power transmission resonator 2 to the power reception resonator 5 is reduced. Can be suppressed.

  In addition, the above-described coupled resonator type wireless power transmission system 1 uses various power receiving side resonators (for example, solenoid type coil resonators) having other configurations in addition to or instead of the power receiving side resonator 5. Is also possible.

  The power-receiving-side resonator 5 can also be used for other coupled resonator type wireless power transmission systems. In this case, even if there is a dielectric around the power receiving resonator 5, the same effect as described above can be expected.

DESCRIPTION OF SYMBOLS 1 Coupling resonator type radio | wireless power transmission system 2 One power transmission side resonator 21 The 1st coils 21a and 21b which comprise the power transmission side resonator 2 Both ends of the 1st coil 22 The 2nd which comprises the power transmission side resonator 2 Coils 22a and 22b of the first coil 23 Capacitors constituting the power transmission side resonator 2 3 Other power transmission side resonators 31 First coil constituting the power transmission side resonator 3 32 Power transmission side resonator 3 Second coil 33 Capacitor constituting power transmission side resonator 3 4 Controller 5 Power receiving side resonator 51 First coil constituting power receiving side resonator 5 52 Second coil constituting power receiving side resonator 5 53 Power receiving Capacitor constituting the side resonator 5 6 Load circuit

Claims (1)

The first coil and the second coil are configured to have a capacitor, and the first coil and the second coil are spiral coils, and the electric field strength is between them by capacitive coupling. Are arranged close to each other so that their electric field strength is small, and one of both ends of the first coil and one of both ends of the second coil are connected via the capacitor. The other end of the first coil and the other end of the second coil are connected to each other without a capacitor , provided that the inner end of the first coil is connected to the other end of the first coil. the inner end of the second coil was divided to be connected without passing through the condenser, and at least one of the power transmission resonator,
A controller for controlling excitation of one power transmission resonator of the at least one power transmission resonator;
A power receiving resonator disposed outside the two coils of the one power transmitting resonator and receiving power transmitted from the one power transmitting resonator;
A coupled resonator type wireless power transmission system comprising:

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