JP6667163B2 - Power transmission device, vehicle equipped with power transmission device, and wireless power transmission system - Google Patents

Description

  The present disclosure relates to a power transmission device that transmits AC power in a non-contact manner by electromagnetic induction between a power transmission coil and a power reception coil, a vehicle equipped with the power transmission device, and a wireless power transmission system.

  Various mobile devices such as mobile phones have become widespread. The power consumption of mobile devices continues to increase due to improvements in functions and performance and diversification of contents. When the power consumption of a mobile device that operates on a battery having a predetermined capacity increases, the operation time of the mobile device decreases. As a technique for compensating for the limitation of the capacity of the battery, a wireless power transmission system has attracted attention. The wireless power transmission system wirelessly transmits AC power from a power transmission device to a power reception device by electromagnetic induction between a power transmission coil in the power transmission device and a power reception coil in the power reception device. In particular, a wireless power transmission system using a resonance type power transmission coil and power reception coil can maintain high transmission efficiency even when the positions of the power transmission coil and the power reception coil are shifted from each other. For this reason, the resonance type wireless power transmission system is applied to various fields.

  2. Description of the Related Art In recent years, a system in which a power transmitting device for charging a mobile device (power receiving device) such as a mobile phone in a non-contact manner is mounted on a vehicle has begun to spread. In such a system, a mobile device can be charged in a car in a contactless manner. It is desirable that the power transmission device be as thin as possible so as not to occupy a lot of space.

JP 2008-205215 A

  However, in the related art, since the power transmission device is reduced in thickness, the loss of the power transmission coil increases, and the transmission efficiency is reduced. Therefore, a power transmission device that transmits AC power with high efficiency has been demanded.

  A power transmission device according to an aspect of the present disclosure is a power transmission device that transmits AC power in a non-contact manner to a power reception device including a power reception coil, and the power transmission device includes a power transmission surface that transmits power to the power reception device. A power transmission circuit that converts DC power input from a DC power supply into AC power, and 2N units (N is 2 or more) provided on the power transmission surface side inside the power transmission device and vertically stacked on the power transmission surface. At least one power transmission coil that includes a (natural number) planar coil and transmits the AC power output from the power transmission circuit to the power reception coil, and a side opposite to the power transmission surface side of the power transmission coil inside the power transmission device. And a magnetic body provided in the first section. When i = 1 to N, the 2N planar coils are, among the 2N planar coils, a planar coil closest to the i-th power transmitting surface and a planar coil closest to the i-th magnetic coil. Are connected in series to form a coil group, and each of the coil groups is connected in parallel.

  A power transmission device according to another aspect of the present disclosure is a power transmission device that transmits AC power in a non-contact manner to a power reception device including a power reception coil, and includes a power transmission surface that transmits power to the power reception device, and a DC power supply. A power transmission circuit for converting input DC power into AC power; and M (M is a natural number of 3 or more) planes provided on the power transmission surface side inside the power transmission device and vertically stacked on the power transmission surface. At least one power transmission coil that includes a coil and transmits the AC power output from the power transmission circuit to the power reception coil, and is provided inside the power transmission device on a side opposite to the power transmission surface side of the power transmission coil. A magnetic material. The M planar coils are two or more planes selected from the planar coil closest to the power transmission surface to the Mth planar coil from the power transmission surface in an order different from the order of 1 to M. The coils have two or more coil groups including a coil group connected in series as one set, and each of the two or more coil groups is connected in parallel.

  A power receiving device according to still another aspect of the present disclosure is a power receiving device that receives AC power from a power transmitting device including a power transmitting coil in a non-contact manner, the power receiving surface receiving power from the power transmitting device, and the received AC power. The power receiving circuit includes a power receiving circuit that converts the power into DC power, and 2N (N is a natural number of 2 or more) planar coils provided on the power receiving surface side inside the power receiving device and vertically stacked on the power receiving surface. At least one power receiving coil that outputs the AC power input from a surface to the power receiving circuit; and a magnetic body provided inside the power receiving device on a side opposite to the power receiving surface side of the power receiving coil. . When i = 1 to N, the 2N planar coils are, among the 2N planar coils, a planar coil closest to the i-th power receiving surface and a planar coil closest to the i-th magnetic coil. Are connected in series to form a coil group, and each of the coil groups is connected in parallel.

  A power receiving device according to still another aspect of the present disclosure is a power receiving device that receives AC power from a power transmitting device including a power transmitting coil in a non-contact manner, the power receiving surface receiving power from the power transmitting device, and the received AC power. A power receiving circuit configured to convert the power into DC power, and M (M is a natural number of 3 or more) planar coils provided on the power receiving surface side inside the power receiving device and vertically stacked on the power receiving surface; At least one power receiving coil that outputs the AC power output from the surface to the power receiving circuit; and a magnetic body provided inside the power receiving device on a side opposite to the power receiving surface of the power receiving coil. . The M planar coils are two or more planes selected from the planar coil closest to the power receiving surface to the M-th planar coil from the power receiving surface in an order different from the order from 1 to M. The coils have two or more coil groups including a coil group connected in series as one set, and each of the two or more coil groups is connected in parallel.

  These general or specific aspects may be implemented in a system, a method, an integrated circuit, a computer program, or a recording medium, and any combination of the system, the apparatus, the method, the integrated circuit, the computer program, and the recording medium. It may be realized by.

  According to the above aspect, it is possible to provide a thin power transmission device that transmits AC power with high efficiency.

It is a figure showing an example of the wireless power transmission system carried in vehicles. FIG. 11 is an exploded perspective view showing a plurality of planar coils having the same configuration as the laminated coil disclosed in Patent Document 1. FIG. 3 is an equivalent circuit diagram of the laminated coil shown in FIG. 2. FIG. 1 is a diagram schematically illustrating a wireless power transmission system including a power transmission device having a magnetic body and a power reception device. It is a perspective view showing the example of composition which arranged a magnetic body at one side of plane coils L1 to L4. It is an equivalent circuit diagram of the power transmission coil shown in FIG. It is a block diagram showing an example of a wireless power transmission system. It is a block diagram showing an example of a power transmission circuit. FIG. 2 is a cross-sectional view of the power transmission coil according to the first embodiment. FIG. 2 is an exploded perspective view of the power transmission coil according to the first embodiment. FIG. 2 is an equivalent circuit diagram of a power transmission coil according to the first embodiment. It is a disassembled perspective view of the power transmission coil in a comparative example. FIG. 9 is an exploded perspective view of a power transmission coil according to the second embodiment. It is an equivalent circuit diagram of the power transmission coil in Embodiment 2. FIG. 11 is an exploded perspective view of a power transmission coil according to a third embodiment. It is an equivalent circuit diagram of the power transmission coil in Embodiment 3. 9 is a graph illustrating characteristics of a power transmission coil according to the first and third embodiments. FIG. 11 is an exploded perspective view of a power transmission coil according to a fourth embodiment. It is an equivalent circuit diagram of the power transmission coil in Embodiment 4. FIG. 9 is an equivalent circuit diagram showing a modification of the first embodiment. FIG. 11 is an equivalent circuit diagram illustrating another modification of the first embodiment. FIG. 14 is a perspective view illustrating a power transmission device according to a fifth embodiment. FIG. 15 is a perspective view illustrating a state where a power receiving device is placed on a power transmitting device according to a fifth embodiment. FIG. 17 is a perspective view illustrating another state in which the power receiving device is placed on the power transmitting device in the fifth embodiment. FIG. 14 is a diagram illustrating a schematic configuration of a power transmission device according to a fifth embodiment. It is a figure showing an example of a wireless power transmission system. It is a figure showing an example of a vehicle provided with a power transmission device. FIG. 4 is a cross-sectional view illustrating a configuration example of a power receiving device including a magnetic body and a plurality of stacked planar coils.

(Knowledge underlying the present disclosure)
The present inventors have found that the following problems occur with respect to the power transmission device described in the section of “Background Art”.

  FIG. 1 is a perspective view illustrating an example of a wireless power transmission system mounted on a vehicle. This system includes a power transmitting device 100 mounted in a console box 400 mounted on a vehicle and a power receiving device 200. The power transmission device 100 includes at least one power transmission coil having a plurality of planar coils stacked vertically on a power transmission surface that transmits power to the power reception device.

  Patent Literature 1 discloses a laminated coil unit used for a wireless power transmission system. This laminated coil unit has a plurality of planar air-core coils. Each coil is formed of a spiral conductive pattern formed on the insulating substrate, and is stacked in the thickness direction of the insulating substrate.

  FIG. 2 is an exploded perspective view showing a plurality of planar coils having the same configuration as the laminated coil disclosed in Patent Document 1. FIG. 3 is a diagram illustrating an equivalent circuit of the plurality of planar coils illustrated in FIG. In this laminated coil, a thin substrate such as a flexible substrate is used as an insulating substrate. One planar coil in which a conductor pattern (0.035 mm) is spirally formed on a flexible substrate is manufactured. Four planar coils are produced in a similar manner. With these four planar coils stacked, each planar coil is electrically connected as shown in FIGS. Two of the four planar coils are connected in series, and the other two are also connected in series. These two pairs of planar coils are connected in parallel. Patent Literature 1 describes that such a configuration can provide a power transmission device that is thin and has an improved Q factor (Quality Factor).

  Generally, if the number of turns and the size of the conductor pattern in each of the plurality of planar coils stacked in this manner are substantially the same, their inductance values will be substantially the same. However, in an actual wireless power transmission system, the inductance values of these planar coils are not constant due to the influence of the magnetic material loaded on the power transmission device 100.

  FIG. 4 is a cross-sectional view schematically illustrating an example of a wireless power transmission system including the power transmission device 100 loaded with the magnetic body 120 and the power reception device 200. The power transmission device 100 in this example includes a power transmission antenna 110, a power transmission circuit 140, and a magnetic body 120. The power receiving device 200 includes a power receiving antenna 210, a power receiving circuit 220, and a secondary battery 230. The power transmission antenna 110 has a power transmission coil including a plurality of planar coils as shown in FIG. 2 and a resonance capacitor (not shown). As shown in FIG. 4, in an actual wireless power transmission system, in order to reduce eddy current loss of the power transmitting antenna 110, a magnetic body 120 may be loaded on the power transmitting antenna 110 on a side opposite to the power transmitting surface 130. Almost. However, when a power transmission device loaded with such a magnetic body 120 in the configuration shown in Patent Document 1 was actually manufactured and evaluated, it was found that a large amount of heat was generated and transmission efficiency was reduced. The present inventors analyzed the cause as follows.

  FIG. 5 is a perspective view showing a configuration example in which a magnetic body 120 is arranged on one side of a group of planar coils L1 to L4 (these are collectively referred to as “power transmission coils”). Although not disclosed in Patent Document 1, the present inventors actually produced a configuration as shown in FIG. 5 and determined the characteristics of the inductance L and the AC resistance R of each of the planar coils L1 to L4 in this state. Analyzed. Table 1 shows the analysis results.

As shown in Table 1, it can be seen that each inductance value changes from a large value to a small value in the order of the planar coil far from the magnetic body 120 and far from the planar coil, that is, in the order of L4 to L1. Here, a general-purpose electromagnetic field analysis simulator was used for the analysis. The analysis conditions were as follows. Each planar coil was formed by a copper pattern on a glass epoxy resin (FR4) substrate. The outer diameter of each planar coil was Φ45 mm, the line width was 0.5 mm, the pitch between the lines was 1 mm, the number of turns was 10 turns, the copper thickness was 70 μm, and the distance between the copper pattern surfaces of each layer was 0.2 mm. The magnetic material had a relative magnetic permeability of 200 and a size of 50 × 50 × 1 mm ³ . The analysis frequency was 150 kHz. An aluminum plate (50 × 50 × 0.5 mm ³ ) (not shown) simulating a heat radiating plate was disposed immediately below the magnetic body.

  FIG. 6 is an equivalent circuit diagram showing the electrical connection of the planar coils L1 to L4. As shown in FIG. 6, the planar coils L1 and L2 are connected in series, and the planar coils L3 and L4 are connected in series. These two sets of planar coil pairs are connected in parallel. The planar coils L1 to L4 are connected to each other. When the inductance values of the planar coils L1 to L4 are represented by L1 to L4, respectively, L1 <L2 <L3 <L4.

  Here, a plurality of coils connected in series will be referred to as a “coil group”. For example, in the example shown in FIG. 6, the planar coils L1 and L2 are a first coil group, and the planar coils L3 and L4 are a second coil group. The combined inductance value of the first coil group is obtained by combining the smallest inductance value L1 and the second smallest inductance value L2 among the four inductance values. The combined inductance value of the second coil group is obtained by combining the largest inductance value L4 and the second largest inductance value L3 among the four inductance values. Therefore, the combined inductance value of the first coil group is smaller than the combined inductance value of the second coil group.

  Thus, in the configuration of the planar coil disclosed in Patent Document 1, a difference occurs between the combined inductance value of the first coil group and the combined inductance value of the second coil group connected in parallel. . Due to this difference, when AC power is transmitted, the balance between the impedance of the first coil group and the impedance of the second coil group is broken. When the impedance balance is lost, the loss due to the current flowing through the stacked planar coils increases. As a result, it was found that heat was generated in the first coil group having a lower impedance, and the transmission efficiency was reduced.

  Note that, in the above example, by disposing the magnetic material, a difference was generated between the inductance value of the first coil group connected in parallel and the inductance value of the second coil group. discovered. However, irrespective of whether a magnetic body is arranged or not, under the condition that a difference occurs between the inductance value of the first coil group and the inductance value of the second coil group connected in parallel, the same applies. Problem may occur.

  The present inventors have intensively studied a technique for suppressing the amount of heat generation and improving transmission efficiency by focusing on the inductance of the planar coil based on the above technical knowledge. The present inventors have conceived the following aspects of the present invention in order to reduce the loss due to current flowing through the stacked planar coils and improve transmission efficiency while reducing the thickness of the power transmission device. .

The power transmission device according to an aspect of the present disclosure includes:
A power transmitting device that transmits AC power in a non-contact manner to a power receiving device including a power receiving coil,
A power transmission surface for transmitting power to the power receiving device,
A power transmission circuit that converts DC power input from a DC power supply into AC power,
The power transmission device includes 2N (N is a natural number of 2 or more) planar coils that are provided on the power transmission surface side inside the power transmission device and that are vertically stacked on the power transmission surface, and the AC power output from the power transmission circuit is included in the power transmission device. At least one power transmission coil for transmitting power to the power reception coil;
A magnetic body provided on the side opposite to the power transmission surface side of the power transmission coil inside the power transmission device,
The 2N planar coils are:
When i = 1 to N, a coil group in which, out of the 2N planar coils, a planar coil closest to the i-th power transmitting surface and a planar coil closest to the i-th magnetic coil are connected in series. Constitute
Each of the coil groups is connected in parallel.

  According to the above aspect, in the 2N planar coils stacked inside the power transmission device, the combined inductance value of each of the coil groups connected in parallel (the plurality of planar coils connected in series) becomes close. Averaged.

  Specifically, when i = 1 to N, among the 2N planar coils, a planar coil closest to the i-th power transmitting surface and a planar coil closest to the i-th magnetic coil are connected in series. Are averaged so that the combined inductance values of the coil groups are close to each other.

  Thus, the impedance balance between the coil groups connected in parallel is prevented from being lost, so that the loss due to the current flowing through the stacked planar coils can be reduced. As a result, unnecessary heat generation can be reduced, and transmission efficiency can be improved.

A power transmission device according to another aspect of the present disclosure,
A power transmitting device that transmits AC power in a non-contact manner to a power receiving device including a power receiving coil,
A power transmission surface for transmitting power to the power receiving device,
A power transmission circuit that converts DC power input from a DC power supply into AC power,
The power transmission device includes M planar coils (M is a natural number of 3 or more) that are provided on the power transmission surface side inside the power transmission device and that are vertically stacked on the power transmission surface, and the AC power output from the power transmission circuit is included in the power transmission device. At least one power transmission coil for transmitting power to the power reception coil;
A magnetic body provided on the side opposite to the power transmission surface side of the power transmission coil inside the power transmission device,
The M planar coils are two or more planes selected from the planar coil closest to the power transmission surface to the Mth planar coil from the power transmission surface in an order different from the order of 1 to M. The coil has two or more coil groups including a coil group connected in series as one set,
Each of the two or more coil groups is connected in parallel.

  According to the above aspect, in the M planar coils stacked inside the power transmitting device, from the planar coil closest to the power transmitting surface to the M-th planar coil from the power transmitting surface, the 1 to M Two or more planar coils selected in an order different from the order have two or more coil groups including a coil group connected in series as one set.

  This makes it possible to average the combined inductance values of the respective coil groups so as to be as close as possible. Since the impedance balance between the coil groups connected in parallel is prevented from being lost, it is possible to reduce the loss due to the current flowing through the stacked planar coils. As a result, unnecessary heat generation can be reduced, and transmission efficiency can be improved.

  Hereinafter, embodiments of the present disclosure will be described. In the following embodiments, the same components are denoted by the same reference numerals. In the following description, description of overlapping items may be omitted.

(Embodiment 1)
[1. overall structure]
FIG. 7 is a block diagram illustrating a schematic configuration of the wireless power transmission system according to the first embodiment of the present disclosure. This wireless power transmission system includes a power transmitting device 100 and a power receiving device 200. Power is transmitted from the power transmitting antenna 110 of the power transmitting device 100 to the power receiving antenna 210 of the power receiving device 200 in a non-contact manner.

  The power receiving device 200 includes a power receiving coil 212, a power receiving antenna 210 having resonance capacitors 214a and 214b, a power receiving circuit 220, and a secondary battery 230. The power receiving coil 212 and the resonance capacitors 214a and 214b form a series and parallel resonance circuit. The power receiving circuit 220 rectifies and outputs the AC power received by the power receiving coil 212. The secondary battery 230 is charged by the DC power output from the power receiving circuit 220. The energy stored in the secondary battery 230 is consumed by a load (not shown).

  The power receiving circuit 220 may include various circuits such as a rectifier circuit, a frequency conversion circuit, a constant voltage / constant current control circuit, and a modulation / demodulation circuit for communication. The received AC energy is configured to be converted to DC energy or low frequency AC energy available to the load. Various sensors that measure the voltage and current output from the power receiving coil 212 may be included in the power receiving circuit 220.

  The power transmission device 100 includes a power transmission antenna 110 including a power transmission coil 112, a resonance capacitor 114, and a power transmission circuit 140. Further, as shown in FIG. 4, inside the power transmission device 100, a magnetic body 120 provided on the side opposite to the power transmission surface 130 with respect to the power transmission antenna 110 is provided. Here, the power transmission surface 130 refers to a surface of the power transmission device 100 that faces the power reception device 200 during a power transmission operation. The power transmission coil 112 is connected in series with the resonance capacitor 114. The resonance capacitor 114 is connected to the power transmission circuit 140.

  The power transmission coil 112 may have, for example, a configuration in which a plurality of one thin planar coils formed of a substrate pattern are stacked. In addition, a winding coil using a copper wire, a litz wire, a twist wire, or the like can be used. The resonance capacitors 114, 214a, and 214b may be provided as needed. The self-resonant characteristics of each coil may be used instead of these capacitors.

  The power transmission circuit 140 includes, for example, a full-bridge type inverter, or an oscillation circuit of class D or class E. FIG. 8 illustrates an example in which the power transmission circuit 140 includes a full-bridge inverter and a control circuit 150 that controls the inverter. The power transmission circuit 140 may include a communication modulation / demodulation circuit and various sensors that measure voltage, current, and the like. The power transmission circuit 140 is connected to an external direct current (DC) power supply 300. DC power input from DC power supply 300 is converted into AC power and output. This AC power is transmitted to the space by the power transmission coil 112.

  The frequency at the time of power transmission is set to, for example, the same value as the resonance frequency of the power transmission resonator formed by the power transmission coil 112 and the resonance capacitor 114. However, it is not limited to this. For example, it may be set to a value within a range of about 85 to 115% of the resonance frequency. The frequency band of the power transmission may be set to a value within a range of, for example, 100 kHz to 200 kHz, but may be set to a value outside this range.

  The DC power supply 300 is a commercial power supply, a primary battery, a secondary battery, a solar cell, a fuel cell, a USB (Universal Serial Bus) power supply, a high-capacity capacitor (for example, an electric double layer capacitor), and a voltage converter connected to the commercial power supply. Or a combination thereof.

  The power transmission circuit 140 includes a control circuit 150 that is a processor that controls the operation of the entire power transmission device 100. The control circuit 150 can be realized by, for example, a combination of a CPU and a memory storing a computer program. The control circuit 150 may be a dedicated integrated circuit configured to implement the operation of the present embodiment. The control circuit 150 performs power transmission control (adjustment of power transmission state) by the power transmission circuit 140.

  The control circuit 150 may include a communication circuit that performs communication with the power receiving device 200. With the communication circuit, for example, information indicating a change in the impedance of the load of the power receiving device 200 can be obtained. The control circuit 150 can instruct the power transmission circuit 140 to change the power transmission parameters based on the information, for example, to supply a constant voltage to the load. Such a transmission parameter may be, for example, the frequency, the phase difference between the switching element pairs of the inverter, or the input voltage of the inverter. When adjusting the input voltage, the power transmission circuit 140 may include a DC / DC converter between the DC power supply 300 and the inverter. By changing these power transmission parameters, the voltage supplied to the load can be changed.

  The power transmission device 100 may include components other than the above components. For example, a display element for displaying the result of detection of the power receiving coil 212 or foreign matter by the control circuit 150 may be provided. Such a display element can be, for example, a light source such as an LED. Further, an oscillation circuit and a detection coil for detecting foreign matter may be provided.

  The configuration of the power receiving device 200 is not limited to the configuration illustrated in FIG. The configuration may be arbitrarily designed as long as the power receiving coil 212 receives at least a part of the energy transmitted from the power transmitting coil 112.

[2. Configuration of power transmission coil]
Next, the configuration of the power transmission coil 112 in the present embodiment will be described. As illustrated in FIG. 4, the power transmission coil 112 is provided on the power transmission surface 130 side inside the power transmission device 100. The power transmission coil 112 includes 2N (N is a natural number equal to or greater than 2) planar coils stacked vertically on the power transmission surface 130. Here, “laminated perpendicular to the power transmission surface 130” means that when viewing 2N planar coils from a direction perpendicular to the power transmission surface 130, at least a part of each planar coil is positioned so as to overlap each other. Means that The centers of the 2N planar coils need not necessarily be located on a straight line perpendicular to the power transmission surface 130. The size and shape of the 2N planar coils need not necessarily be the same. The power transmission coil 112 transmits the AC power output from the power transmission circuit 140 to the power reception coil 212.

  When i = 1 to N, the 2N planar coils in the present embodiment are, among the 2N planar coils, the planar coil closest to the i-th power transmitting surface 130 and the i-th planar coil close to the magnetic body 120. A plurality of coil groups are formed by connecting the planar coils in series. Each of these coil groups is connected in parallel. The 2N planar coils can be realized by, for example, a multilayer substrate in which 2N substrates in which a conductor pattern is wound on an insulating substrate or a dielectric substrate are stacked. Hereinafter, a detailed configuration of the power transmission coil 112 will be described with an example of N = 2.

  FIG. 9 is a diagram illustrating a cross section of a part of the power transmission coil 112 in the present embodiment. This example is an example in which four plane coils in the case of N = 2 are configured by a four-layer substrate. The power transmission coil 112 is realized by a multilayer substrate in which a planar coil formed by winding a copper pattern 160 on a glass epoxy resin 170 as an insulating substrate is laminated. The magnetic body 120 is loaded on the power transmission coil 112 on the side opposite to the power transmission surface 130.

  FIG. 10 is an exploded perspective view of the power transmission coil 112 in the present embodiment. The planar coils in each layer are connected by through holes. Both ends of the power transmission coil 112 are connected to terminals 180. Here, the layer of the planar coil L1 closest to the power transmission surface 130 is defined as a first layer. A through-hole connecting the inner end of the first-layer planar coil L1 to the inner end of the fourth-layer planar coil L4; the inner end of the second-layer planar coil L2 and the inner end of the third-layer planar coil L3 And the through-hole connecting them are arranged so as to be shifted from each other so as not to conduct with each other.

  FIG. 11 is an equivalent circuit diagram of the power transmission coil 112 in the present embodiment. Although not shown, each of the planar coils L1 to L4 is coupled to each other. As shown in FIG. 10 and FIG. 11, the planar coils L1 and L4 connected in series constitute a first coil group, and the planar coils L2 and L3 connected in series constitute a second coil group. I have. The first coil group and the second coil group are connected in parallel.

  Here, due to the influence of the magnetic body 120, the order of the magnitude of the inductance value of each of the planar coils L1 to L4 is the same as the order of the distance from the power transmission surface 130 (L1 <L2 <L3 <L4). Therefore, the inductance value of the first coil group constituted by the planar coil L1 closest to the power transmitting surface 130 and the planar coil L4 closest to the magnetic material, the planar coil L2 closest to the power transmitting surface 130 and The inductance value of the second coil group formed by the second planar coil L3 closest to the magnetic body 120 is substantially the same. Therefore, it is possible to suppress the impedance balance between the first coil group and the second coil group from being lost. As a result, the effect of reducing the loss of the power transmission coil 112 in the parallel connection is improved.

  The present inventors connected the four plane coils L1 to L4 as shown in FIG. 10 under the same conditions as the analysis described with reference to FIG. The characteristics of the power transmission coil according to Example 1 were analyzed. On the other hand, the characteristics of the power transmission coil were also analyzed for a comparative example in which four plane coils L1 to L4 were connected as shown in FIG. Table 2 shows the analysis results of the combined inductance L and the AC resistance R of the power transmission coil in Example 1 and Comparative Example.

  As shown in Table 2, the value of the inductance L is almost unchanged, but the value of the AC resistance R is reduced by 17.4% in Example 1 as compared with the comparative example. From this, it is understood that the configuration of the present embodiment can suppress unnecessary heat generation and improve transmission efficiency.

(Embodiment 2)
FIG. 13 is an exploded perspective view illustrating a configuration of the power transmission coil 112 according to the second embodiment of the present disclosure. FIG. 14 is an equivalent circuit diagram of the power transmission coil 112 in the present embodiment. The power transmission coil 112 according to the present embodiment is different from the first embodiment in that N = 3, that is, has six planar coils. Hereinafter, components common or corresponding to the first embodiment are denoted by the same reference numerals, and description of common items will not be repeated.

  The power transmission coil 112 in the present embodiment employs a six-layer, three-parallel configuration in order to further reduce the loss from the first embodiment. As shown in FIGS. 13 and 14, the power transmission coil 112 in the present embodiment has six planar coils L1 to L6. The planar coils L1 and L6 are connected in series to form a first coil group. The planar coils L2 and L5 are connected in series to form a second coil group. The planar coils L3 and L4 are connected in series to form a third coil group. The first to third coil groups are connected in parallel. As described above, the first coil group includes the planar coil L1 closest to the power transmission surface 130 and the planar coil L6 closest to the magnetic body 120. The second coil group includes a planar coil L <b> 2 closest to the power transmission surface 130 and a planar coil L <b> 5 second closest to the magnetic body 120. The third coil group includes a planar coil L3 closest to the power transmission surface 130 and a planar coil L4 third closest to the magnetic body 120. With such a configuration, the inductance value of the first coil group, the inductance value of the second coil group, and the inductance value of the third coil group are substantially the same.

  Also in the present embodiment, it is possible to suppress the impedance balance of each of the first to third coil groups from being lost. As a result, the effect of reducing the loss of the power transmission coil 112 in the parallel connection is improved.

  In the present embodiment, N = 3, but N = 4 or N> 4. By increasing the number of layers and the number of layers in a range where the thickness of the power transmission coil 112 is allowed, a further loss reduction effect can be expected.

(Embodiment 3)
Next, a third embodiment of the present disclosure will be described. The power transmission coil 112 in the present embodiment includes M (M is a natural number of 3 or more) planar coils stacked perpendicularly to the power transmission surface 130. The M planar coils include two or more planar coils selected in an order different from the order of 1 to M from the planar coil closest to the power transmitting surface 130 to the M-th planar coil from the power transmitting surface 130. One set includes two or more coil groups including a coil group connected in series. Each of the two or more coil groups is connected in parallel. Here, “an order different from the order of 1 to M” means an order in which at least a part of the order different from the order of 1 to M is included. As an example, it is assumed that M ≧ 4 and a plane coil closest to the power transmission surface 130, a plane coil closest to the second, and a plane coil closest to the fourth form one coil group. In this case, the arrangement of the second closest planar coil and the fourth closest planar coil is different from the arrangement of 1 to M. For this reason, this order corresponds to “an order different from the order of 1 to M”. Hereinafter, the present embodiment will be described with an example of M = 4.

  FIG. 15 is an exploded perspective view showing the configuration of the power transmission coil 112 when M = 4. FIG. 16 is an equivalent circuit diagram of FIG. As shown in FIGS. 15 and 16, the power transmission coil 112 in the present embodiment has four planar coils L1 to L4. The planar coils L1 and L3 are connected in series to form a first coil group. The planar coils L2 and L4 are connected in series to form a second coil group. The first and second coil groups are connected in parallel. As described above, the first coil group includes the planar coil L1 closest to the power transmission surface 130 and the planar coil L3 closest to the power transmission surface 130. The second coil group includes a planar coil L2 closest to the power transmission surface 130 and a planar coil L4 closest to the power transmission surface 130.

  Here, due to the influence of the magnetic body 120, the order of the magnitude of the inductance value of each of the planar coils L1 to L4 is the same as the order of the distance from the power transmission surface 130 (L1 <L2 <L3 <L4). Therefore, the inductance value of the first coil group formed by the plane coils L1 and L3 and the inductance value of the second coil group formed by the plane coils L2 and L4 are averaged. That is, by connecting the planar coils in an order different from the order of the magnitudes of the inductance values in series, the inductance values of the first and second coil groups are averaged. Therefore, it is possible to suppress the impedance balance between the first coil group and the second coil group from being lost. As a result, the effect of reducing the loss of the power transmission coil 112 in the parallel connection is improved.

  The present inventors connected the four plane coils L1 to L4 as shown in FIG. 15 under the same conditions as the analysis described with reference to FIG. 5 in order to verify the effect of the present embodiment. The characteristics of the power transmission coil of Example 2 were analyzed. Table 3 shows the analysis results of the combined inductance L and the AC resistance R of the power transmission coil in Example 2 and the comparative example described above.

  As shown in Table 3, the value of the inductance L is almost the same, but the value of the AC resistance R is reduced by 11.8% in Example 2 as compared with the comparative example. From this, it is understood that the configuration of the present embodiment can suppress unnecessary heat generation and improve transmission efficiency.

  FIG. 17 is a graph showing the result of comparing the characteristics of the power transmission coil in the present embodiment and the first embodiment with the characteristics of the power transmission coil in the comparative example. It can be seen that the AC resistance R is particularly reduced by changing the connection of each of the planar coils L1 to L4 from the connection in the comparative example.

(Embodiment 4)
FIG. 18 is an exploded perspective view illustrating a configuration of the power transmission coil 112 according to the fourth embodiment of the present disclosure. FIG. 19 is an equivalent circuit diagram of the power transmission coil 112 in the present embodiment. The power transmission coil 112 in the present embodiment is different from the third embodiment in that M = 6, that is, has six planar coils. Hereinafter, description of matters common to the third embodiment will not be repeated.

  As shown in FIGS. 18 and 19, the power transmission coil 112 in the present embodiment has six planar coils L1 to L6. The planar coils L1, L3, L6 are connected in series to form a first coil group. The planar coils L2, L4, L5 are connected in series to form a second coil group. The first and second coil groups are connected in parallel. As described above, the first coil group includes the planar coil L1 closest to the power transmission surface 130, the planar coil L3 closest to the third, and the planar coil L6 closest to the sixth. The second coil group includes a planar coil L2 closest to the power transmission surface 130, a planar coil L4 closest to the fourth, and a planar coil L5 closest to the fifth. Since each of the first coil group and the second coil group is selected in a different order from the order of 1 to M (= 6), the inductance values of the first and second coil groups are averaged. You. Therefore, it is possible to suppress the impedance balance between the first coil group and the second coil group from being lost. As a result, the effect of reducing the loss of the power transmission coil 112 in the parallel connection is improved.

  In the present embodiment and the third embodiment, at least one set of plane coils is selected in a different order from the order of the inductance values, among the plurality of series-connected plane coils constituting each of the plurality of coil groups. I have. Thereby, the inductance values of the coil group are averaged. For example, in the configuration shown in FIG. 19, the planar coil L4 and the planar coil L5 constituting the second coil group are connected in the order of the inductance value, but the planar coil L2 and the planar coil L4 are connected in the order of the inductance value. They are connected in an order different from the order. For this reason, the inductance values of the first and second coil groups are averaged, and the loss reduction effect is improved.

In the present embodiment, M = 6, but M ≧ 7 may be satisfied. By increasing the number of layers and the number of layers in a range where the thickness of the power transmission coil 112 is allowed, a further loss reduction effect can be expected.

  In addition, a plane coil may be newly laminated on the power transmission coil in which a plurality of plane coils are laminated in each of the above-described embodiments, and may be connected in series or in parallel.

  FIG. 20A is an equivalent circuit diagram illustrating a modification in which a planar coil La is newly connected in series to the power transmission coil 112 according to the first embodiment. FIG. 20B is an equivalent circuit diagram illustrating a modification in which a planar coil Lb is newly connected in parallel to the power transmission coil 112 according to the first embodiment. 20A and 20B are effective when the inductance needs to be finely adjusted in the circuit design of the wireless power transmission system. Not limited to the configuration of the first embodiment, a new planar coil may be added to the configurations of the second to fourth embodiments. Although not shown, the plane coil to be newly added may not be one. For example, one may be added in series and in parallel, two in series, or two in parallel.

(Embodiment 5)
Next, a fifth embodiment according to the power transmission device 100 including the plurality of power transmission coils 112 will be described.

  21A to 21C are diagrams illustrating the appearance and operation of the power transmission device 100 according to the fifth embodiment. The power transmission device 100 is a wireless charger and has a flat plate structure. As shown in FIG. 21A, the power transmission device 100 includes a plurality of power transmission coils 112 (seven power transmission coils 112a to 112g in this example) arranged in a line. Each power transmission coil has a configuration in which a plurality of planar coils according to any of the above-described embodiments are stacked. Each power transmission coil has a shape that is short in the arrangement direction (horizontal direction in the drawing) and long in the direction perpendicular to the arrangement direction. Although not shown, the power transmission device 100 also includes a power transmission circuit that supplies AC power to each power transmission coil, and a control circuit that controls a connection state between the power transmission circuit and each power transmission coil.

  When the power receiving device 200 including the power receiving coil 212 approaches the power transmitting device 100, the control circuit electrically connects the two power transmitting coils closest to the power receiving coil 212 to the power transmitting circuit. For example, in the state shown in FIG. 21B, only two power transmission coils 112c and 112d are connected to the power transmission circuit. In the state shown in FIG. 21C, only two power transmission coils 112f and 112g are connected to the power transmission circuit. In this example, power is always supplied to two power transmission coils, but the number of power transmission coils that are simultaneously supplied with power may be a number other than two. The number of power transmission coils that are simultaneously supplied with power may be smaller than the total number of power transmission coils.

  FIG. 22 is a block diagram illustrating a schematic configuration of the power transmission device 100 according to the present embodiment. Components common or corresponding to those in FIG. 7 are denoted by the same reference numerals, and description of common items will not be repeated.

  The power transmission device 100 includes a plurality of power transmission coils 112, a plurality of switches 190, a resonance capacitor 114, and a power transmission circuit 140. Power transmission circuit 140 includes control circuit 150. The plurality of switches 190 are connected to the plurality of power transmission coils 112, respectively. Here, “connected” means connected so as to be electrically conductive. The plurality of power transmission coils 112 are connected to the power transmission circuit 140 in parallel with each other via the plurality of switches 190. One end of each power transmission coil is connected to one electrode of the capacitor 114. The other electrode of the capacitor 114 is connected to the power transmission circuit 140. Each of the plurality of switches 190 is connected to a terminal of the plurality of power transmission coils 112 to which the capacitor 114 is not connected. This is because the voltage fluctuates greatly between the capacitor 114 and the plurality of power transmission coils 112.

  The control circuit 150 detects a relative position of the power receiving coil 212 with respect to the plurality of power transmitting coils 112. In addition, foreign matter, such as metal, which is close to the power transmission coil 112 may be detected. The detection of the position of the power receiving coil 212 and the detection of foreign matter can be performed based on measured values of parameters that vary with changes in impedance such as voltage, current, frequency, and inductance on the circuit. More specifically, the control circuit 150 sequentially turns on the plurality of switches 190 by a fixed number (for example, two), and measures one of the above parameters each time. When a value that deviates from the prescribed range is measured, it can be determined that the power receiving coil 212 or a foreign object exists near the power transmitting coil that is supplying power at that time. To enable such detection, the control circuit 150 may include a detection circuit (not shown). In the present disclosure, the detection of the power receiving coil 212 and the detection of the foreign matter are not limited to a specific method, and can be performed by any known method.

  The control circuit 150 in the present embodiment selects two power transmission coils used for power transmission according to the relative positions of the power reception coils 212 with respect to the plurality of power transmission coils 112. Then, the conduction state of the plurality of switches 190 is switched such that AC power is supplied from the power transmission circuit 140 to only the two selected power transmission coils. As a result, AC energy is transmitted to the space from the two selected power transmission coils.

  In the present embodiment, the power transmission device 100 has a plurality of power transmission coils. Thereby, the range in which power can be transmitted is expanded as compared with a configuration having a single power transmission coil. Therefore, the positioning of the power receiving device 200 can be easily performed.

(Other embodiments)
The technology of the present disclosure is not limited to the embodiments described above, and various modifications are possible. Hereinafter, examples of other embodiments will be described.

  FIG. 23 is a diagram illustrating a configuration example of a wireless power transmission system that transmits power from a wall to a robot 500 used in a hospital or the like in a non-contact manner. In this example, the power transmission device 100 is embedded in a wall. The robot 500 includes the same components as the power receiving device 200 illustrated in FIG. 4 or FIG. Further, it includes a driving electric motor 240 and a plurality of wheels 270 for movement. According to such a system, for example, electric power can be transmitted from a wall to a robot 500 in a hospital in a non-contact manner, and charging can be performed automatically without human assistance. Note that, instead of the robot 500, a similar configuration may be applied to an electric vehicle such as an electric vehicle.

  FIG. 24 is a block diagram schematically illustrating a vehicle 600 equipped with the power transmission device 100 according to the present disclosure. Vehicle 600 includes power transmission device 100 inside console box 400 shown in FIG. 1, for example. Thus, the user can charge an electronic device such as a mobile phone in the vehicle 600.

  In the above embodiments, the power transmission coil has a plurality of stacked planar coils, but the power receiving coil may have a similar plurality of planar coils. Since the above-described problem may occur in a device in which a magnetic body is arranged near a power receiving coil, it is effective to apply the configuration of the coil of the present disclosure to such a device.

  FIG. 25 is a cross-sectional view illustrating an example of a wireless power transmission system including such a power receiving device 200. In this example, the power receiving device 200 includes a power receiving surface 260 that receives power from the power transmitting device 100, a power receiving circuit 220 that converts received AC power into DC power, and at least a power receiving surface 260 provided inside the power receiving device 200. The power receiving device includes one power receiving coil (a part of the power receiving antenna 210) and a magnetic body 250 provided inside the power receiving device 200 on the side opposite to the power receiving surface 260 with respect to the power receiving coil. The at least one power receiving coil includes 2N (N is a natural number of 2 or more) planar coils vertically stacked on the power receiving surface 260, and outputs AC power input from the power receiving surface 260 to the power receiving circuit 220. Assuming that i = 1 to N, the 2N plane coils include, among the 2N plane coils, a plane coil closest to the power receiving surface 260 and a plane coil closest to the i-th magnetic body 250. A coil group connected in series is configured. Each of these coil groups is connected in parallel. Here, the “power receiving surface” means a surface of the power receiving device 200 facing the power transmitting surface 130 of the power transmitting device 100 when receiving power.

  The at least one power receiving coil includes M (M is a natural number of 3 or more) planar coils stacked vertically on the power receiving surface 260 instead of the above configuration. From the planar coil closest to the first to the Mth planar coil from the power receiving surface 260, a coil group in which two or more planar coils selected in an order different from the order of 1 to M are connected in series as a set. And two or more coil groups. Also in this case, each of the two or more coil groups is connected in parallel.

  In the example illustrated in FIG. 25, the power transmission device 100 includes the magnetic body 120, and the power transmission coil in the power transmission antenna 110 includes a plurality of stacked planar coils according to the present disclosure. However, without being limited to this example, when the power receiving device 200 is provided with the magnetic body 250 and the stacked planar coils, the power transmitting device 100 may not be provided with the magnetic body 120 and the stacked planar coils. .

  As described above, the present inventors have conceived the following aspects of the invention in order to reduce the loss due to the current flowing through the stacked planar coils and improve the transmission efficiency.

(1) The power transmission device according to the first aspect of the present disclosure includes:
A power transmitting device that transmits AC power in a non-contact manner to a power receiving device including a power receiving coil,
A power transmission surface for transmitting power to the power receiving device,
A power transmission circuit that converts DC power input from a DC power supply into AC power,
The power transmission device includes 2N (N is a natural number of 2 or more) planar coils that are provided on the power transmission surface side inside the power transmission device and that are vertically stacked on the power transmission surface, and the AC power output from the power transmission circuit is included in the power transmission device. At least one power transmission coil for transmitting power to the power reception coil;
A magnetic body provided on the side opposite to the power transmission surface side of the power transmission coil inside the power transmission device,
The 2N planar coils are:
When i = 1 to N, a coil group in which, out of the 2N planar coils, a planar coil closest to the i-th power transmitting surface and a planar coil closest to the i-th magnetic coil are connected in series. Constitute
Each of the coil groups is connected in parallel.

  According to the above aspect, in the 2N planar coils stacked inside the power transmission device, the combined inductance value of each of the coil groups connected in parallel (the plurality of planar coils connected in series) becomes close. Averaged.

  Specifically, when i = 1 to N, among the 2N planar coils, a planar coil closest to the i-th power transmitting surface and a planar coil closest to the i-th magnetic coil are connected in series. Are averaged so that the combined inductance values of the coil groups are close to each other.

  Thus, the impedance balance between the coil groups connected in parallel is prevented from being lost, so that the loss due to the current flowing through the stacked planar coils can be reduced. As a result, unnecessary heat generation can be reduced, and transmission efficiency can be improved.

(2) The power transmitting device according to the second aspect of the present disclosure is the power transmitting device according to the first aspect of the present disclosure,
When N is 2, a planar coil closest to the power transmitting surface and a planar coil closest to the magnetic material are connected in series, and the planar coil closest to the power transmitting surface is And the second closest planar coil is connected in series.

  According to the above aspect, in the four planar coils stacked inside the power transmission device, the combined inductance value of each of the coil group connected in parallel (the plurality of planar coils connected in series) becomes close. Averaged.

(3) The power transmitting device according to the third aspect of the present disclosure is the power transmitting device according to the first aspect of the present disclosure,
When N is 3, a planar coil closest to the power transmission surface and a planar coil closest to the magnetic material are connected in series, and the planar coil closest to the power transmission surface is a second coil. A second planar coil is connected in series to the power transmission surface, and a third planar coil connected to the magnetic body is connected in series to the power transmitting surface.

  According to the above aspect, in the six planar coils stacked inside the power transmitting device, the combined inductance value of each of the coil group connected in parallel (the plurality of planar coils connected in series) becomes close. Averaged.

(4) The power transmitting device according to the fourth aspect of the present disclosure is the power transmitting device according to any one of the first to third aspects of the present disclosure,
The planar coil closest to the power transmission surface has the smallest inductance value, and the planar coil closest to the magnetic material has the largest inductance value.

  According to the above aspect, the planar coil having the smallest inductance value and the planar coil having the largest inductance value belong to one and the same coil group, so that the effect of averaging the combined inductance value of each coil group is high. Become.

(5) The power transmitting device according to a fifth aspect of the present disclosure is the power transmitting device according to any one of the first to fourth aspects of the present disclosure,
The 2N planar coils are a multilayer substrate obtained by laminating 2N substrates each having a conductor pattern wound on an insulating substrate or a dielectric substrate.

  According to the above aspect, the thickness of the power transmission device can be reduced.

(6) The power transmission device according to the sixth aspect of the present disclosure is the power transmission device according to any one of the first to fifth aspects of the present disclosure,
The at least one power transmission coil includes a plurality of power transmission coils.

  According to the above aspect, when a plurality of power transmission coils are arranged in a direction parallel to the power transmission surface, the area in which power can be transmitted can be increased.

(7) The power transmitting device according to a seventh aspect of the present disclosure is the power transmitting device according to any one of the first to sixth aspects of the present disclosure,
The power transmission coil includes a first additional planar coil connected in series with the 2N planar coils, or a second additional planar coil connected in parallel with the 2N planar coils.

  According to the above aspect, when it is necessary to finely adjust the inductance in circuit design, the inductance can be easily adjusted.

  (8) A vehicle according to an eighth aspect of the present disclosure is a vehicle equipped with the power transmission device according to any one of the first to seventh aspects of the present disclosure.

  According to the above aspect, the electronic device can be charged in the vehicle with high power transmission efficiency.

  (9) A wireless power transmission system according to a ninth aspect of the present disclosure includes the power transmitting device according to any one of the first to seventh aspects of the present disclosure, and the power receiving device.

  According to the above aspect, a wireless power transmission system including a thin power transmission device with high power transmission efficiency can be realized. Such a wireless power transmission system can be, for example, a medical robot or a transport robot system.

(10) A power transmission device according to a tenth aspect of the present disclosure is provided
A power transmission coil used for a power transmission device that transmits AC power in a non-contact manner to a power reception device including a power reception coil,
In the power transmission device,
A power transmission surface for transmitting power to the power receiving device,
A power transmission circuit that converts DC power input from a DC power supply into AC power,
At least one power transmission coil for transmitting the AC power output from the power transmission circuit to the power reception coil,
A magnetic body provided on the side opposite to the power transmission surface side of the power transmission coil inside the power transmission device,
The power transmission coil,
The power transmission device includes 2N (N is a natural number of 2 or more) planar coils provided on the power transmission surface side inside the power transmission device and vertically stacked on the power transmission surface,
The 2N planar coils are:
When i = 1 to N, a coil group in which, out of the 2N planar coils, a planar coil closest to the i-th power transmitting surface and a planar coil closest to the i-th magnetic coil are connected in series. Constitute
Each of the coil groups are connected in parallel,
Power transmission coil.

  According to the above aspect, the same effect as in the first aspect can be obtained.

  (11) A power transmitting antenna according to an eleventh aspect of the present disclosure includes the power transmitting coil according to the tenth aspect of the present disclosure and a resonance capacitor.

  According to the above aspect, the same effect as in the first aspect can be obtained.

(12) A power transmission device according to a twelfth aspect of the present disclosure includes:
A power transmitting device that transmits AC power in a non-contact manner to a power receiving device including a power receiving coil,
A power transmission surface for transmitting power to the power receiving device,
A power transmission circuit that converts DC power input from a DC power supply into AC power,
The power transmission device includes M planar coils (M is a natural number of 3 or more) that are provided on the power transmission surface side inside the power transmission device and that are vertically stacked on the power transmission surface, and the AC power output from the power transmission circuit is included in the power transmission device. At least one power transmission coil for transmitting power to the power reception coil;
A magnetic body provided on the side opposite to the power transmission surface side of the power transmission coil inside the power transmission device,
The M planar coils are two or more planes selected from the planar coil closest to the power transmission surface to the Mth planar coil from the power transmission surface in an order different from the order of 1 to M. The coil has two or more coil groups including a coil group connected in series as one set,
Each of the two or more coil groups is connected in parallel.

  According to the above aspect, in the M planar coils stacked inside the power transmitting device, from the planar coil closest to the power transmitting surface to the M-th planar coil from the power transmitting surface, the 1 to M Two or more planar coils selected in an order different from the order have two or more coil groups including a coil group connected in series as one set.

  This makes it possible to average the combined inductance values of the respective coil groups so as to be as close as possible. Since the impedance balance between the coil groups connected in parallel is prevented from being lost, it is possible to reduce the loss due to the current flowing through the stacked planar coils. As a result, unnecessary heat generation can be reduced, and transmission efficiency can be improved.

(13) The power transmitting device according to a thirteenth aspect of the present disclosure is the power transmitting device according to the twelfth aspect of the present disclosure,
The planar coil closest to the power transmitting surface has the smallest inductance value, and the planar coil closest to the M-th transmitting coil has the largest inductance value.

  According to the above aspect, a coil group in which two or more planar coils selected in an order different from the order of magnitude of the inductance value are connected in series as one set. Therefore, the combined inductance values of the coil groups can be averaged so as to be as close as possible.

(14) The power transmitting device according to a fourteenth aspect of the present disclosure is the power transmitting device according to the twelfth or thirteenth aspect of the present disclosure,
The M planar coils are a multilayer substrate obtained by laminating M substrates each having a conductor pattern wound on an insulating substrate or a dielectric substrate.

  According to the above aspect, the thickness of the power transmission device can be reduced.

(15) The power transmitting device according to a fifteenth aspect of the present disclosure is the power transmitting device according to any one of the twelfth to fourteenth aspects of the present disclosure,
The at least one power transmission coil includes a plurality of power transmission coils.

  According to the above aspect, when a plurality of power transmission coils are arranged in a direction parallel to the power transmission surface, the area in which power can be transmitted can be increased.

(16) The power transmitting device according to a sixteenth aspect of the present disclosure is the power transmitting device according to any one of the twelfth to fifteenth aspects of the present disclosure,
The power transmission coil includes a third additional planar coil connected in series with the M planar coils, or a fourth additional planar coil connected in parallel with the M planar coils.

  According to the above aspect, when it is necessary to finely adjust the inductance in circuit design, the inductance can be easily adjusted.

  (17) A vehicle according to a seventeenth aspect of the present disclosure is a vehicle equipped with the power transmission device according to any one of the twelfth to sixteenth aspects of the present disclosure.

  According to the above aspect, the electronic device can be charged in the vehicle with high power transmission efficiency.

  (18) A wireless power transmission system according to an eighteenth aspect of the present disclosure includes the power transmitting device according to any one of the twelfth to sixteenth aspects of the present disclosure, and the power receiving device.

  According to the above aspect, a wireless power transmission system including a thin power transmission device with high power transmission efficiency can be realized. Such a wireless power transmission system can be, for example, a medical robot or a transport robot system.

(19) The power transmission coil according to a nineteenth aspect of the present disclosure includes:
A power transmission coil used for a power transmission device that transmits AC power in a non-contact manner to a power reception device including a power reception coil,
In the power transmission device,
A power transmission surface for transmitting power to the power receiving device,
A power transmission circuit that converts DC power input from a DC power supply into AC power,
At least one power transmission coil for transmitting the AC power output from the power transmission circuit to the power reception coil,
A magnetic body provided on the side opposite to the power transmission surface side of the power transmission coil inside the power transmission device,
The power transmission coil,
M (M is a natural number of 3 or more) planar coils provided on the power transmission surface side inside the power transmission device and vertically stacked on the power transmission surface,
The M planar coils are two or more planes selected from the planar coil closest to the power transmission surface to the Mth planar coil from the power transmission surface in an order different from the order of 1 to M. The coil has two or more coil groups including a coil group connected in series as one set,
Each of the two or more coil groups is connected in parallel,
Power transmission coil.

  According to the above aspect, the same effect as in the twelfth aspect can be obtained.

  (20) A power transmitting antenna according to a twentieth aspect of the present disclosure includes the power transmitting coil according to the nineteenth aspect of the present disclosure and a resonance capacitor.

  According to the above aspect, the same effect as in the twelfth aspect can be obtained.

(21) The power receiving device according to a twenty-first aspect of the present disclosure includes:
A power receiving device that receives AC power from a power transmitting device including a power transmitting coil in a non-contact manner,
A power receiving surface for receiving power from the power transmitting device,
A power receiving circuit that converts the received AC power to DC power,
The power receiving apparatus includes 2N (N is a natural number of 2 or more) planar coils that are provided on the power receiving surface side of the power receiving device and that are vertically stacked on the power receiving surface, and that the AC power input from the power receiving surface is included in the power receiving device. At least one power receiving coil that outputs to the power receiving circuit;
A magnetic body provided on the opposite side to the power receiving surface side of the power receiving coil inside the power receiving device,
The 2N planar coils are:
When i = 1 to N, a coil group in which, of the 2N planar coils, a planar coil closest to the i-th power receiving surface and a planar coil closest to the i-th magnetic coil are connected in series. Constitute
Each of the coil groups are connected in parallel,
Power receiving device.

  According to the above aspect, a power receiving device having the same effect as that of the first aspect can be realized.

(22) The power receiving coil according to a twenty-second aspect of the present disclosure,
A power receiving coil used for a power receiving device that receives AC power in a non-contact manner from a power transmitting device including a power transmitting coil,
In the power receiving device,
A power receiving surface for receiving power from the power transmitting device,
A power receiving circuit that converts the received AC power to DC power,
The power receiving apparatus includes 2N (N is a natural number of 2 or more) planar coils that are provided on the power receiving surface side of the power receiving device and that are vertically stacked on the power receiving surface, and that the AC power input from the power receiving surface is included in the power receiving device. At least one power receiving coil that outputs to the power receiving circuit;
A magnetic body provided on the opposite side to the power receiving surface side of the power receiving coil inside the power receiving device,
The receiving coil,
The 2N planar coils are:
When i = 1 to N, a coil group in which, of the 2N planar coils, a planar coil closest to the i-th power receiving surface and a planar coil closest to the i-th magnetic coil are connected in series. Constitute
Each of the coil groups are connected in parallel,
Receiving coil.

  According to the above aspect, the same effect as in the twenty-first aspect can be obtained.

  (23) A power receiving antenna according to a twenty-third aspect of the present disclosure includes the power receiving coil according to the twenty-second aspect of the present disclosure, and a resonance capacitor.

  According to the above aspect, the same effect as in the twenty-first aspect can be obtained.

(24) The power receiving device according to a twenty-fourth aspect of the present disclosure includes:
A power receiving device that receives AC power from a power transmitting device including a power transmitting coil in a non-contact manner,
A power receiving surface for receiving power from the power transmitting device,
A power receiving circuit that converts the received AC power to DC power,
The power receiving device includes M planar coils (M is a natural number of 3 or more) that are provided on the power receiving surface side of the power receiving device and that are vertically stacked on the power receiving surface, and the AC power output from the power receiving surface is included in the power receiving device. At least one power receiving coil that outputs to the power receiving circuit;
A magnetic body provided on the opposite side to the power receiving surface side of the power receiving coil inside the power receiving device,
The M planar coils are two or more planes selected from the planar coil closest to the power receiving surface to the M-th planar coil from the power receiving surface in an order different from the order from 1 to M. The coil has two or more coil groups including a coil group connected in series as one set,
Each of the two or more coil groups is connected in parallel.

  According to the above aspect, a power receiving device having the same effects as the twelfth aspect can be realized.

(25) The power receiving coil according to the twenty-fifth aspect of the present disclosure,
A power receiving coil used for a power receiving device that receives AC power in a non-contact manner from a power transmitting device including a power transmitting coil,
In the power receiving device,
A power receiving surface for receiving power from the power transmitting device,
A power receiving circuit that converts the received AC power to DC power,
The power receiving device includes M planar coils (M is a natural number of 3 or more) that are provided on the power receiving surface side of the power receiving device and that are vertically stacked on the power receiving surface, and the AC power output from the power receiving surface is included in the power receiving device. At least one power receiving coil that outputs to the power receiving circuit;
A magnetic body provided on the opposite side to the power receiving surface side of the power receiving coil inside the power receiving device,
The M planar coils are:
From the planar coil closest to the power receiving surface to the M-th planar coil from the power receiving surface, two or more planar coils selected in a different order from the order of 1 to M are connected in series as a set. Having two or more coil groups including the coil group
Each of the two or more coil groups is connected in parallel.

  According to the above aspect, the same effect as in the twenty-fourth aspect can be obtained.

  (26) A power receiving antenna according to a twenty-sixth aspect of the present disclosure includes the power receiving coil according to the twenty-fifth aspect of the present disclosure, and a resonance capacitor.

  According to the above aspect, the same effect as in the twenty-fourth aspect can be obtained.

  The power transmission device and the wireless power transmission system of the present disclosure are widely applicable to, for example, charging or power supply to an electric vehicle, an AV device, a battery, a medical device, and the like.

REFERENCE SIGNS LIST 100 power transmission device 110 power transmission antenna 112 power transmission coil 114 resonance capacitor 120 magnetic body 130 power transmission surface 140 power transmission circuit 150 control circuit 160 copper pattern 170 glass epoxy resin 180 terminal 190 switch 200 power reception device 210 power reception antenna 212 power reception coil 214a, 214b resonance capacitor 220 Power receiving circuit 230 Secondary battery 240 Driving electric motor 250 Magnetic body 260 Power receiving surface 270 Wheel 300 DC power supply 400 Console box 500 Hospital robot 600 Vehicle

Claims (8)

A power transmitting device that transmits AC power in a non-contact manner to a power receiving device including a power receiving coil,
A power transmission surface for transmitting power to the power receiving device,
A power transmission circuit that converts DC power input from a DC power supply into AC power,
M (M is an even number equal to or greater than 6) planar coils provided on the power transmission surface side inside the power transmission device and vertically stacked on the power transmission surface and having the same material, number of turns, and size, At least one power transmission coil for transmitting the AC power output from the power transmission circuit to the power reception coil,
A magnetic body provided on the side opposite to the power transmission surface side of the power transmission coil inside the power transmission device,
The M planar coils include two or more coil groups, each coil group includes two or more planar coils connected in series as one set, and in at least one of the two or more coil groups, From the planar coil closest to the power transmission surface to the M-th planar coil from the power transmission surface, two or more planar coils selected in an order different from the order from 1 to M are connected in series as a set. And
The planar coil closest to the power transmission surface has the smallest inductance value, the planar coil closest to the Mth power transmission surface has the largest inductance value,
The planar coil closest to the power transmission surface and the planar coil closest to the Mth power transmission surface belong to one and the same coil group among the two or more coil groups,
Each of the two or more coil groups is connected in parallel,
Power transmission equipment. The M planar coils are a multilayer substrate obtained by laminating M substrates each having a conductive pattern wound on an insulating substrate or a dielectric substrate.
The power transmission device according to claim 1 . The at least one power transmission coil includes a plurality of power transmission coils;
Transmitting device according to claim 1 or 2. The power transmission coil includes a third additional planar coil connected in series with the M planar coils, or a fourth additional planar coil connected in parallel with the M planar coils.
Power transmission device according to any one of claims 1 to 3. Vehicle equipped with a power transmission device according to any one of claims 1 to 4. A power transmission device according to any one of claims 1 to 4 , and the power reception device,
Wireless power transmission system. A power transmission coil used for a power transmission device that transmits AC power in a non-contact manner to a power reception device including a power reception coil,
In the power transmission device,
A power transmission surface for transmitting power to the power receiving device,
A power transmission circuit that converts DC power input from a DC power supply into AC power,
At least one power transmission coil for transmitting the AC power output from the power transmission circuit to the power reception coil,
A magnetic body provided on the side opposite to the power transmission surface side of the power transmission coil inside the power transmission device,
The power transmission coil,
M (M is an even number equal to or greater than 6) planar coils provided on the power transmission surface side inside the power transmission device and vertically stacked on the power transmission surface and having the same material, number of turns, and size,
The M planar coils include two or more coil groups, each coil group includes two or more planar coils connected in series as one set, and in at least one of the two or more coil groups, From the planar coil closest to the power transmission surface to the M-th planar coil from the power transmission surface, two or more planar coils selected in an order different from the order from 1 to M are connected in series as a set. And
The planar coil closest to the power transmission surface has the smallest inductance value, the planar coil closest to the Mth power transmission surface has the largest inductance value,
The planar coil closest to the power transmission surface and the planar coil closest to the Mth power transmission surface belong to one and the same coil group among the two or more coil groups,
Each of the two or more coil groups is connected in parallel,
Power transmission coil. A power transmission antenna comprising the power transmission coil according to claim 7 and a resonance capacitor.

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