JP2018113765A - Power transmission system and power transmission sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power transmission system in simple geometric configuration capable of suppressing reduction of power transmission efficiency resulting from relative positional deviation between coils.SOLUTION: A power transmission system is provided with: a rectangular power transmission coil 11 arranged on a first plane; and a rectangular power reception coil 21 arranged on a second plane facing the first plane in parallel, and having long sides orthogonal to long sides of the power transmission coil 11 and longer than short sides of the transmission coil 11, and short sides shorter than the long sides of the power transmission coil 11. The power reception coil 21 receives power with no-contact from the power transmission coil 11.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a contactless power transmission system and a power transmission sheet to which a power transmission device of the power transmission system is applied.

  In the non-contact type power transmission method, a magnetic field generated by a current flowing in a coil on the power transmission side is electromagnetically coupled to a current flowing in a coil on the power receiving side, and a current flows in the coil on the power receiving side. In such a non-contact type power transmission system, a “magnetic field resonance coupling system” is known in which a capacitor is connected to each of the power transmission and reception coils to form a resonance circuit and power is transmitted at the resonance frequency. The magnetic resonance coupling method is capable of high-efficiency power transmission if the distance between the power transmission side coil and the power reception side coil is about several tens of centimeters to several meters, and is expected to be applied to various applications. Yes. However, in general, in the magnetic field resonance coupling method, when the positions of the axes of the coils on the power transmission side and the power reception side are shifted from each other in the direction perpendicular to the axis, the power transmission efficiency is deteriorated.

  On the other hand, a technique has been proposed in which a plurality of unit coils formed on one plane so as to exhibit a plurality of regions that generate magnetic fields in the same direction are used to suppress a reduction in power transmission efficiency due to misalignment. (See Patent Document 1). However, in the coil described in Patent Document 1, the geometrical shape and the coil design are complicated, and the length of the winding per coil increases.

JP 2012-178417 A

  The present invention relates to a power transmission system capable of suppressing a reduction in power transmission efficiency due to a relative displacement between coils with a simple geometric configuration, and power transmission using the power transmission device of the power transmission system The purpose is to provide a sheet for use.

  To achieve the above object, according to a first aspect of the present invention, there is provided a rectangular power transmission coil disposed on a first plane and a second power transmission coil disposed on a second plane facing the first plane in parallel. A rectangular power receiving coil having a long side perpendicular to the long side and having a long side longer than the short side of the power transmission coil and a short side shorter than the long side of the power transmission coil. The main point is that the power transmission system receives power by contact.

  According to a second aspect of the present invention, a plurality of rectangular power transmission coils periodically arranged with a constant pitch, the same orientation, and the same dimension along one direction on the first plane are opposed in parallel to the first plane. A rectangular power receiving coil that is disposed on the second plane and has a long side that is perpendicular to the long side of the power transmission coil and has a long side that is longer than the short side of the power transmission coil and a short side that is shorter than the long side of the power transmission coil The power transmission coil is a power transmission system that sequentially receives power from each of the plurality of power transmission coils by moving in parallel on the first plane.

  A third aspect of the present invention is an electric power transmission sheet for transmitting electric power to a moving body traveling in parallel above the first plane with electric power transmitted in a non-contact manner from the first plane, A plurality of rectangular power transmission coils periodically arranged with a constant pitch, the same orientation, and the same dimension along at least one direction on the first plane, and the second plane facing the first plane in parallel is movable A rectangular shape having a long side orthogonal to the long side of the power transmission coil, the long side being longer than the short side of the power transmission coil, and the short side shorter than the long side of the power transmission coil. The gist of the invention is a power transmission sheet in which power is sequentially transmitted from each of the plurality of power transmission coils to the power reception coil.

  According to the present invention, a power transmission system capable of suppressing a reduction in power transmission efficiency due to a relative displacement between coils with a simple geometric configuration and a power transmission device of the power transmission system are applied. A power transmission sheet can be provided.

FIG. 1 is a schematic block diagram illustrating the basic configuration of the power transmission system according to the first embodiment of the present invention. FIG. 2 is a plan view illustrating two coil units of the power transmission system according to the first embodiment. 3 is a cross-sectional view as seen from the direction II-II in FIG. FIG. 4 is a plan view illustrating a rectangular coil that is a simulation model of the power transmission coil and the power reception coil according to the first embodiment. FIG. 5 is a plan view illustrating a square coil which is a simulation model of a comparative example of the rectangular coil of FIG. FIG. 6 is a table showing parameters of the rectangular and square simulation models. FIG. 7A is a plan view illustrating a pair of square coils and a pair of rectangular coils facing each other. FIG. 7B is a plan view illustrating a pair of square coils and a pair of rectangular coils when the displacement is 33%. FIG. 7C is a plan view illustrating a pair of square coils and a pair of rectangular coils when the positional deviation is 66%. FIG. 8 is a graph showing the relationship between the displacement and the coupling coefficient for each of the pair of rectangular coils and the pair of square coils. FIG. 9 is a graph showing the relationship between the displacement and the power transmission efficiency (matching efficiency) of each of the pair of rectangular coils and the pair of square coils. FIG. 10 is a plan view for explaining the positional deviation in the planar direction of a pair of rectangular coils. FIG. 11 is a table showing actual measurement values of parameters of the actual measurement coil corresponding to the parameters of the simulation model of the rectangular coil. FIG. 12 is a graph showing measured values of transmission efficiency of a pair of rectangular coils and approximate curves thereof together with the simulation results of FIG. FIG. 13 is a plan view illustrating a coil having an area ratio of ½. FIG. 14 is a plan view for explaining a coil having an area ratio of 1/4. FIG. 15 is a schematic block diagram illustrating a power transmission device provided in a power transmission system according to the second embodiment of the present invention. FIG. 16 is a plan view illustrating a state in which the power transmission system according to the second embodiment is applied to a contactless power transmission system of a moving body. FIG. 17 is a plan view for explaining an overlapping region when the power receiving coil moves with respect to the power transmitting coil. FIG. 18 is a graph showing the relationship between the positional deviation and the power transmission efficiency of each of the pair of rectangular coils and the pair of square coils. FIG. 19 is a graph showing the relationship between the positional deviation and the output voltage for each of the pair of rectangular coils and the pair of square coils. FIG. 20 is a plan view illustrating a power transmission coil unit included in a power transmission system according to another embodiment of the present invention. FIG. 21 is a schematic block diagram illustrating a power transmission device included in a power transmission system according to another embodiment of the present invention. FIG. 22 is a plan view for explaining a power transmission coil and a power reception coil of a power transmission system according to another embodiment of the present invention. FIG. 23 is a perspective view illustrating a power transmission coil of a power transmission system according to another embodiment of the present invention. FIG. 24 is a graph showing the relationship between the displacement in the X-axis direction between coils and the power transmission efficiency of a power transmission system according to another embodiment of the present invention. FIG. 25 is a graph showing the relationship between the positional deviation in the Y-axis direction between coils and the power transmission efficiency in a power transmission system according to another embodiment of the present invention.

  Hereinafter, first and second embodiments of the present invention will be described with reference to the drawings. In the description of the drawings, the same or similar parts are denoted by the same or similar reference numerals, and redundant description is omitted. However, the drawings are schematic, and the relationships and ratios of dimensions may differ from actual ones. Moreover, the part from which the relationship and ratio of a mutual dimension differ also in between drawings may be contained. Further, the following embodiments exemplify systems and apparatuses for embodying the technical idea of the present invention, and the technical idea of the present invention is the material, shape, structure, and arrangement of component parts. Etc. are not specified below.

 In addition, the upper and lower definitions such as “upper” and “lower” in the following description are merely definitions for convenience of description, and do not limit the technical idea of the present invention. For example, if the object is observed by being rotated by 90 °, the upper and lower sides and the left and right are read interchangeably, and if the object is observed after being rotated by 180 °, the upper and lower sides are reversed and read.

(First embodiment)
As shown in FIG. 1, the power transmission system according to the first embodiment of the present invention includes a power transmission device 10 having a power transmission coil 11 and a power reception device 20 having a power reception coil 21 that receives power from the power transmission coil 11 in a contactless manner. With. The planar shape of the power transmission coil 11 and the power reception coil 21 is a rectangle as shown in FIG. In the power transmission system according to the first embodiment, a resonance circuit is configured by connecting a capacitor to each of the power transmission and reception coils. A magnetic field generated when a current having a frequency near the resonance frequency of the resonance circuit flows through the rectangular power transmission coil 11 vibrates in the vicinity of the resonance frequency of the power reception-side resonance circuit having the rectangular power reception coil 21. 11 is a magnetic power resonance type wireless power transmission system in which power is transmitted from 11 to a receiving coil 21 opposed to each other by magnetic resonance.

  The power transmission device 10 includes a power transmission coil unit 30 having a rectangular power transmission coil 11, a power transmission side resonance capacitor 12 that forms a power transmission side resonance circuit (11, 12) together with the power transmission coil 11, and a power transmission side resonance circuit (11, 12). A power transmission side matching circuit 13 that performs impedance matching, a power supply circuit 14 that supplies an alternating current to the power transmission side resonance circuits (11, 12) via the power transmission side matching circuit 13, and a first that controls driving of the power supply circuit 14 The control circuit 15 is provided.

  As shown in FIGS. 2 and 3, the physical configuration of the power transmission coil unit 30 includes a rectangular flat plate-like first shielding plate 31 made of a metal material such as aluminum, and a first above the first shielding plate 31. A rectangular flat first magnetic sheet 32 made of a ferromagnetic material, such as ferrite, and a rectangular flat plate extending along the first magnetic sheet 32 above the first magnetic sheet 32. It is a sheet-like structure provided with the 1st cover 33 which covers the shape-like power transmission coil 11, the 1st shielding board 31, the 1st magnetic sheet 32, and the power transmission coil 11. FIG.

  As shown in FIG. 1, the power receiving device 20 includes a power receiving coil unit 40 having a rectangular power receiving coil 21, a power receiving side resonance capacitor 22 that forms a power receiving side resonance circuit (21, 22) together with the power receiving coil 21, and a power receiving side resonance. A power receiving side matching circuit 23 that performs impedance matching of the circuits (21, 22) and a load that is a load side circuit that consumes power supplied from the power receiving side resonance circuit (21, 22) via the power receiving side matching circuit 23 A circuit 24 and a second control circuit 25 that controls driving of the load circuit 24 are provided.

  Similar to the power transmission coil unit 30, the physical configuration of the power reception coil unit 40 includes a rectangular flat plate-like second shielding plate 41 made of a metal material such as aluminum, and a second shielding as shown in FIGS. 2 and 3. A rectangular flat plate-like second magnetic sheet 42 made of a ferromagnetic material such as ferrite is disposed below the plate 41 along the second shielding plate 41, and a second magnetic sheet 42 below the second magnetic sheet 42. A rectangular flat power receiving coil 21 extending along the magnetic sheet 42 and a second cover 43 covering the second shielding plate 41, the second magnetic sheet 42 and the power receiving coil 21 are provided.

  The first shielding plate 31 constituting the power transmission coil unit 30 supports the first magnetic sheet 32 with a predetermined interval by a spacer or the like not shown in FIG. The first shielding plate 31 can function as a heat radiating plate that radiates heat generated by the power transmission coil 11 and the first magnetic sheet 32 in addition to shielding the magnetic flux generated on the power transmission coil 11 side. The first magnetic sheet 32 prevents an eddy current generated in the shielding plate 31 due to a change in magnetic flux generated below the power transmission coil 11 and reduces heat loss. The first magnetic sheet 32 is electrically insulated from the power transmission coil 11 by a spacer or a coating made of an insulating material such as a resin, and supports the power transmission coil 11 with a predetermined interval.

  As shown in FIG. 2, the power transmission coil 11 is wound in a rectangular shape on a first plane along the first shielding plate 31 and the first magnetic sheet 32. Specifically, the power transmission coil 11 includes a winding such as a litz wire wound along four sides of a rectangle having a long side having a length a1 and a short side having a width b1 on the first plane. The power transmission coil 11 is a spiral type (circular type) coil formed in a generally rectangular flat plate shape. 2 and 3, the number of turns of the power transmission coil 11 is illustrated as two. However, the number of turns of the power transmission coil 11 may be singular or may be three or more.

  The second shielding plate 41 of the power receiving coil unit 40 supports the second magnetic sheet 42 with a predetermined interval, for example, by a spacer or the like (not shown). The second shielding plate 41 can function as a heat radiating plate that dissipates heat generated by the receiving coil 21 and the second magnetic sheet 42 in addition to shielding the magnetic flux generated on the receiving coil 21 side. The second magnetic sheet 42 prevents an eddy current generated in the shielding plate 41 due to a change in magnetic flux generated above the power receiving coil 21 and reduces heat loss. The second magnetic sheet 42 is electrically insulated from the power receiving coil 21 by a spacer or a coating made of an insulating material such as a resin, and supports the power receiving coil 21 with a predetermined interval.

  As shown in FIG. 2, the power receiving coil 21 is wound in a rectangular shape on a second plane along the second shielding plate 41 and the second magnetic sheet 42. Specifically, the power receiving coil 21 includes a winding such as a litz wire wound along four sides of a rectangle having a long side having a length a2 and a short side having a width b2 on the second plane. The power receiving coil 21 is a spiral (circular) coil formed in a generally rectangular plate shape. 2 and 3, the number of turns of the power transmission coil 11 is illustrated as two. However, the number of turns of the power transmission coil 11 may be singular or may be three or more. Is the same as that of the power transmission coil 11.

  Here, the axis of the power transmission coil 11 is defined so as to coincide with the normal line of the first plane passing through the rectangular centroid, and the axis of the power reception coil 21 coincides with the normal line of the second plane passing through the centroid of the rectangle. Is defined as Since the second plane formed by the power receiving coil 21 and the first plane formed by the power transmission coil 11 are parallel to each other, the normal line of the first plane and the normal line of the second plane are defined in the same direction. As shown in FIG. 2, the power transmission system according to the first embodiment is characterized in that the long side of the power transmission coil 11 is orthogonal to the long side of the power reception coil 21 in a plane pattern as viewed from the axial direction.

  In the power transmission system according to the first embodiment, the relative positions of the power transmission coil 11 and the power reception coil 21 change within a certain range by making the long side of the power transmission coil 11 and the long side of the power reception coil 21 orthogonal to each other. Even so, the area of the transmission region R defined by the portion where the planar pattern of the power transmission coil 11 and the planar pattern of the power reception coil 21 overlap can be made constant. That is, by making the long side of the power transmission coil 11 and the long side of the power reception coil 21 orthogonal to each other, the magnetic flux received by the power reception coil 21 from the power transmission coil 11 becomes constant, so that the change in the power transmission efficiency η is suppressed.

  In the example shown in FIGS. 2 and 3, the long side of the power transmission coil 11 is 45 with respect to each of the two sides along one direction (Y-axis direction) of the first shielding plate 31 and the first magnetic sheet 32. It is arranged so as to be inclined, and the long side of the power receiving coil 21 is inclined by 45 ° with respect to each of two sides along one direction (X-axis direction) of the second shielding plate 41 and the second magnetic sheet 42. Although it is a case where the long side of the power transmission coil 11 is arranged and orthogonal to the long side of the power reception coil 21, the power transmission system according to the first embodiment is not limited to the orientation relationship shown in FIG.

  For example, it is also possible to arrange the power transmission coil 11 so that the long side is inclined by 40 ° with respect to each of the two sides along one direction (Y-axis direction) of the first shielding plate 31 and the first magnetic sheet 32. In this case, if the long side of the power receiving coil 21 is disposed so as to be inclined by 50 ° with respect to each of the two sides along one direction (X-axis direction) of the second shielding plate 41 and the second magnetic sheet 42. The orientation in which the long side of the power transmission coil 11 is orthogonal to the long side of the power reception coil 21 can be selected. As described above, even if an orientation other than 45 ° inclination is adopted in the absolute coordinate system, if the long side of the power transmission coil 11 and the long side of the power reception coil 21 are orthogonal, the power transmission coil 11 and the power reception coil 21 Even when the relative position changes within a certain range, the area of the transmission region R defined by the portion where the planar pattern of the power transmission coil 11 and the planar pattern of the power reception coil 21 overlap can be maintained constant. That is, even if an orientation other than 45 ° inclination is adopted with respect to a specific coordinate system, the power receiving coil 21 is separated from the power transmitting coil 11 as long as the long side of the power transmitting coil 11 and the long side of the power receiving coil 21 are orthogonal to each other. Since the received magnetic flux is constant, a change in the power transmission efficiency η due to a change in the relative position between the power transmission coil 11 and the power reception coil 21 is suppressed.

  Similarly, for example, the long side of the power transmission coil 11 is disposed so as to be inclined by 30 ° with respect to each of the two sides along one direction (Y-axis direction) of the first shielding plate 31 and the first magnetic sheet 32, Even if the long side of the power receiving coil 21 is disposed so as to be inclined by 60 ° with respect to each of the two sides along one direction (X-axis direction) of the second shielding plate 41 and the second magnetic sheet 42, the power transmitting coil 11 Can be selected, and the area of the transmission region R defined by the portion where the planar pattern of the power transmission coil 11 and the planar pattern of the power reception coil 21 overlap can be maintained constant.

  As shown in FIG. 2, the length a2 of the long side of the power receiving coil 21 is longer than the width b1 of the short side of the power transmission coil 11, and the width b2 of the short side of the power receiving coil 21 is the length of the long side of the power transmission coil 11. Shorter than a1. The power reception coil 21 receives power from the power transmission coil 11 in a non-contact manner in a state where the long side is orthogonal to the long side of the power transmission coil 11 and overlaps the power transmission coil 11 as a planar pattern. Specifically, the transmission region R defined by the portion where the planar pattern of the power receiving coil 21 overlaps the planar pattern of the power transmitting coil 11 has a first side having the same length as the width b1 of the short side of the power transmitting coil 11, and the power receiving Power is received from the power transmission coil 11 in a non-contact manner in a rectangular shape having the same length as the short side width b2 of the coil 21 and the second side adjacent to the first side. When receiving power from the power transmission coil 11, the power reception coil 21 faces the power transmission coil 11 in parallel with each other on a second plane along the first plane formed by the power transmission coil 11.

  The long side length a2 and the short side width b2 of the power receiving coil 21 may be the same as the long side length a1 and the short side width b1 of the power transmission coil 11, respectively. That is, the power receiving coil 21 may have the same dimensions as the power transmitting coil 11.

  Here, since the 1st shielding board 31, the 1st magnetic sheet 32, and the 1st cover 33 should just be arrange | positioned so that the whole area | region of the power transmission coil 11 may be included as a plane pattern, it follows the power transmission coil 11 A rectangular shape may be sufficient and the rectangular shape in which the long side of the power transmission coil 11 is included diagonally may be sufficient. Similarly, since the 2nd shielding board 41, the 2nd magnetic sheet 42, and the 2nd cover 43 should just be arrange | positioned so that the whole area | region of the receiving coil 21 may be included as a plane pattern, it follows the receiving coil 21. The rectangular shape may be sufficient and the rectangular shape which includes the power transmission coil 11 diagonally may be sufficient.

  The transmission-side resonance capacitor 12 is connected in series with the power transmission coil 11. The power transmission side resonance capacitor 12 has a capacitance that determines the resonance frequency of the power transmission side resonance circuit (11, 12). The drive frequency of the power supply circuit 14 is set near the resonance frequency of the power transmission side resonance circuit (11, 12). The power transmission side matching circuit 13 is an impedance matching circuit designed or adjusted so that the power transmission efficiency η from the power transmission device 10 to the power reception device 20 is maximized. In power transmission, matching of an optimal value set in advance is performed. Used as a fixed impedance matching circuit fixed to impedance. As the power supply circuit 14, various circuits that supply AC power having a resonance frequency of the power transmission side resonance circuit (11, 12) can be used. For example, an AC / DC converter that converts AC power from a system power source or the like into DC power, and DC power supplied from the AC / DC converter is converted to AC power having the resonance frequency of the power transmission side resonance circuit (11, 12). A circuit including an inverter may be used. The power supply circuit 14 supplies an alternating current having a frequency near the resonance frequency of the power transmission side resonance circuit (11, 12) to the power transmission side resonance circuit (11, 12) via the power transmission side matching circuit 13.

  The power receiving side resonance capacitor 22 is connected in series with the power receiving coil 21. The power reception side resonance capacitor 22 has a capacitance that determines the resonance frequency of the power reception side resonance circuit (21, 22). The power receiving side matching circuit 23 is an impedance matching circuit designed or adjusted so that the power transmission efficiency η from the power transmitting device 10 to the power receiving device 20 is maximized. In power transmission, a matching of a preset optimum value is performed. Used as a fixed impedance matching circuit fixed to impedance. The load circuit 24 includes, for example, a storage battery that stores power supplied from the rectifier in addition to a rectifier that converts AC power supplied from the power receiving resonance circuit (21, 22) into DC power via the power receiving matching circuit 23. Various loads such as an electric motor can be included. The electric power supplied from the power receiving side resonance circuit (21, 22) through the power receiving side matching circuit 23 is supplied to the storage battery and the load of the load circuit 24. Or you may make it supply the alternating current power transmitted from the power transmission apparatus 10 to various loads, such as an electric motor, directly or via an AC / DC converter.

  For example, the first control circuit 15 may be configured by a computer such as a microcontroller having a processor, a memory, and an input / output interface, or may be realized by a specialized analog circuit or the like. The first control circuit 15 controls the operation of the power transmission device 10 by controlling the operation of the power supply circuit 14. For example, the first control circuit 15 transmits a drive signal to the power supply circuit 14 in response to the power receiving coil unit 40 being disposed at a predetermined position with respect to the power transmitting coil unit 30. The power supply circuit 14 generates AC power of a predetermined frequency supplied to the power transmission side resonance circuit (11, 12) by an inverter in accordance with the drive signal. The first control circuit 15 transmits a signal for notifying the start of power transmission from the power transmission device 10 to the power reception device 20 by wireless communication or a signal for requesting the start of power transmission from the power transmission device 10 from the power reception device 20. You may make it receive.

  For example, the second control circuit 25 may be configured by a computer such as a microcontroller having a processor, a memory, and an input / output interface, or may be realized by a specialized analog circuit or the like. The second control circuit 25 controls the operation of the power receiving device 20 by controlling the operation of the load circuit 24. For example, the second control circuit 25 supplies a drive signal to the load circuit 24 when AC power is supplied to the power transmission side resonance circuits (11, 12), that is, when power transmission from the power transmission coil 11 is started. Send. For example, the load circuit 24 generates predetermined DC power to be supplied to a load such as a storage battery by a converter such as a rectifier according to the drive signal, and closes a relay that opens and closes the wiring between the converter and the storage battery. By setting the state, DC power is supplied to the storage battery and the load. The second control circuit 25 may cause the power transmission device 10 to start power transmission by transmitting a signal requesting the start of power transmission to the power transmission device 10 by wireless communication.

  In the non-contact power transmission using the magnetic field resonance coupling method, the power transmission efficiency η is determined by the product of the coupling coefficient k between the coils and the Q value of the resonance circuit. Since the Q value is determined by the self-inductance and winding resistance of each coil, it is constant if the frequency is constant. On the other hand, the coupling coefficient k changes depending on the magnetic coupling state between the coils. In general, when the positions of the coil axes deviate from each other in the direction perpendicular to the axis, the magnetic flux received by the coil on the power receiving side changes, the coupling coefficient k changes, and as a result, the power transmission efficiency η changes. .

  As already described, since the planar pattern of the power receiving coil 21 is set so as to overlap perpendicularly to the planar pattern of the power transmitting coil 11, the power receiving coil 21 is relatively flat with the power transmitting coil 11 in the planar direction (perpendicular to the axis). The area of the transmission region R does not change as long as it moves in parallel within a predetermined range. Thus, according to the power transmission system according to the first embodiment, the area of the transmission region R is constant even if the relative positional relationship between the power receiving coil 21 and the power transmitting coil 11 varies. For this reason, the magnetic flux that the power receiving coil 21 receives from the power transmission coil 11 is constant, and the change in the power transmission efficiency η due to the change in the relative position between the power receiving coil 21 and the power transmission coil 11 is suppressed.

-Simulation-
Hereinafter, the technical effect of the power transmission system according to the first embodiment will be described using simulation results obtained by the three-dimensional electromagnetic field simulator ANSYS HFSS (registered trademark).

  As shown in FIG. 4, as a simulation model corresponding to the power transmission coil 11 or the power reception coil 21 included in the power transmission system according to the first embodiment, four sides of a rectangle having a long side of length a and a short side of width b. A coil P consisting of windings wound with 2 turns along the line is defined. The length a = 45 cm and the width b = 15 cm. The simulation regarding the power transmission between the power transmission coil 11 and the power reception coil 21 is executed using a pair of coils P (coil P1 and coil P2) facing each other so that the long sides are orthogonal to each other as a planar pattern.

Moreover, as shown in FIG. 5, as a simulation model as a comparative example of the coil P according to the first embodiment, a winding wound with two turns along four sides of a square having one side of a length c. A coil Q consisting of The length c of one side of the square was set to c = a / (2 ^1/2 ) so that the diagonal length of the square was equal to the length a of the long side of the coil P. The simulation regarding the power transmission between the square coils is executed by using a pair of coils Q (coil Q1 and coil Q2) facing each other so that one side is parallel to one side of the other coil as a planar pattern.

  As shown in FIG. 6, for the rectangular coil P according to the first embodiment and the square coil Q according to the comparative example, the winding is a copper wire having a diameter of 3 mm, and the distance between adjacent windings is 10 mm. Set to. The self-inductance of the coil P is calculated as 3.2 μH, and the capacitance of the resonance capacitor that forms a resonance circuit with the coil P is calculated as 43 pF. The self-inductance of the coil Q is 4.0 μH, and the capacitance of the resonance capacitor that forms a resonance circuit with the coil Q is calculated to be 34 pF. The resonance frequency of the resonance circuit having the coil P and the resonance circuit having the coil Q is 13.56 MHz.

  As shown in FIG. 7A, with reference to the position where the square coil Q1 and the coil Q2 according to the comparative example face each other (coincide as a plane pattern), as shown in FIGS. 7B and 7C, the square coil Q1 Further, the value of the positional deviation in the case where the pair of coils are translated in the plane direction from the directly facing (coincidence in a plan view) is defined using the ratio of the shifted region of the coil Q2 as a parameter. As described above, the length a of each long side of the coil P1 and the coil P2 is equal to the length of each diagonal line of the coil Q1 and the coil Q2. Therefore, the coil P1 and the coil P2 are inclined at 45 ° × n (n is an integer) with respect to the sides of the coils Q1 and Q2, and the centers of gravity coincide with the centers of gravity of the coils Q1 and Q2, respectively. Assuming a state in which the coil P1 and the coil P2 are arranged, values of positional deviations of the coils P1 and P2 are defined.

  As shown in FIG. 7A, when the positional deviation is 0%, the pair of coils Q1 and Q2 according to the comparative example and the pair of coils P1 and P2 according to the first embodiment face each other. Here, as shown in FIG. 7B, when the coil Q2 is translated by c / 3 in one direction (the positive direction of the X axis) along one side of the coil Q1 or the coil Q2 according to the comparative example, 1/3 Since ≈33%, the positional deviation in the X-axis direction between the coil Q1 and the coil Q2 is defined as 33%. Therefore, even when the coil P2 according to the first embodiment is translated by c / 3 in the positive direction of the X axis from the state shown in FIG. 7A, the coils P1 and P2 according to the first embodiment are also included. A positional deviation of 33% in the X-axis direction is applied.

  Similarly, as shown in FIG. 7C, when the coil Q2 according to the comparative example is translated by 2c / 3 in the positive direction of the X axis from the state shown in FIG. 7A, the X axis direction between the coil Q1 and the coil Q2 Is 2 / 3≈66%. 7A, when the coil P2 according to the first embodiment is translated by 2c / 3 in the positive direction of the X axis, the positional deviation in the X axis direction between the coils P1 and P2 is 66%. Applied. As shown in FIGS. 7A to 7C, the area of the transmission region R where the coil P1 and the coil P2 according to the first embodiment overlap is constant = 100% when the positional deviation in the X-axis direction is at least 0% to 66%. It is. On the other hand, the area of the overlapping portion of the coil Q1 and the coil Q2 according to the comparative example is reduced to 66% when the positional deviation is 33% and 33% when the positional deviation is 66%.

  Next, the design of simulation models corresponding to the power transmission side matching circuit 13 and the power receiving side matching circuit 23 will be described. First, Z parameters of a two-terminal pair circuit corresponding to each of the pair of coils P according to the first embodiment and the pair of coils Q according to the comparative example are acquired by analysis using ANSYS HFSS (registered trademark). As shown in FIGS. 7A to 7C, the Z parameter is calculated for each of cases where the positional deviation in the X-axis direction is 0%, 33%, and 66%.

  Then, by a circuit analysis using MATLAB (registered trademark), a matching efficiency (power transmission efficiency η) is calculated when a resonant capacitor and a matching circuit are added to the two-terminal pair circuit having each Z parameter. The shape of the matching circuit and the value of each element are determined by pattern search so that the average value of each power transmission efficiency η in the three types of arrangements is maximized. Moreover, the coupling coefficient k was calculated using each Z parameter acquired by ANSYS HFSS (registered trademark). In calculating the coupling coefficient k, the frequency was 13.56 MHz, and the distance between the coils was 10 cm.

  Using the simulation model designed as described above, the coupling coefficient k of each of the rectangular coil P and the square coil Q when the positional deviation in the X-axis direction is 0% to 66% is calculated, and the calculation result is shown in FIG. This is shown in FIG. Similarly, the matching efficiency (power transmission efficiency η) of each of the rectangular coil P and the square coil Q when the positional deviation in the X-axis direction is 0% to 66% is calculated, and the calculation result is shown in FIG. It was.

  As shown in FIG. 8, the coupling coefficient k of the square coil Q according to the comparative example greatly changes in the range of 0% to 66% in the positional deviation in the X-axis direction, while the rectangular shape according to the first embodiment. The coupling coefficient k of the coil P is substantially constant when the positional deviation in the X-axis direction is in the range of 0% to 66%. Thereby, if the area of the region where the opposing coils overlap is constant, the change of the coupling coefficient k is substantially constant, and the coupling coefficient k of the rectangular coil P according to the first embodiment is related to the comparative example. Compared to the square coil Q, it was confirmed that it is less likely to change due to a positional shift.

  As shown in FIG. 9, the power transmission efficiency η of the square coil Q according to the comparative example maintains a high value of approximately 90% or more in the range where the positional deviation in the X-axis direction is 0% to 35%. As the positional deviation in the X-axis direction changes from 35% to 66%, it significantly decreases. On the other hand, the power transmission efficiency η of the rectangular coil P according to the first embodiment is substantially constant while maintaining a high value of approximately 90% or more in a range where the positional deviation in the X-axis direction is 0% to 66%. is there. When the positional deviation in the X-axis direction is 0%, 33%, and 66%, the average value of the power transmission efficiency η of the coil Q is 77.8%, and the average value of the power transmission efficiency η of the coil P is It was 93.1%. Accordingly, it was confirmed that the power transmission efficiency η of the rectangular coil P is less likely to change due to the positional deviation in the X-axis direction than the square coil Q and can be maintained at a high value.

  Similarly, using the simulation model described above, a pair of rectangular coils P facing each other so that their long sides are orthogonal to each other as a planar pattern are not only in the positive direction of the X axis but also in the X axis direction and the Y axis direction. A simulation was performed in the case where the position was shifted. Specifically, as shown in FIG. 10, the coil P2 is changed to the coil P1 so that the center of gravity of one coil P1 is the point G0 and the center of gravity of the other coil P2 is coincident with the points G1 to G8 as a plane pattern. On the other hand, the power transmission efficiency η in the case of relative movement was calculated by simulation. The X axis and the Y axis were defined such that the angle formed by the X axis direction and the long side of the coil P1 was 45 ° with the point G0 as the origin.

  When the center of gravity of the coil P2 is the point G0, the positional deviation of the coil P in the XY plane is 0% in the X-axis direction and 0% in the Y-axis direction. In this case, the power transmission efficiency η between the coils P is 94. 3%. When the center of gravity of the coil P2 is the point G1, the positional deviation in the XY plane is 66% in the X-axis direction and 0% in the Y-axis direction. In this case, the power transmission efficiency η is 91.6%. Similarly, the positional deviation at the point G2 is 33% in the X-axis direction and −33% in the Y-axis direction, and the power transmission efficiency η in this case is 95.0%. In the case of the point G3, the positional deviation was 0% in the X-axis direction and −66% in the Y-axis direction, and the power transmission efficiency η in this case was 89.4%. In the case of the point G4, the positional deviation was −33% in the X-axis direction and −33% in the Y-axis direction, and the power transmission efficiency η in this case was 94.9%. In the case of the point G5, the positional deviation is −66% in the X-axis direction and 0% in the Y-axis direction, and the power transmission efficiency η in this case is 91.6%. In the case of the point G6, the positional deviation was −33% in the X-axis direction and 33% in the Y-axis direction, and the power transmission efficiency η in this case was 94.8%. In the case of the point G7, the positional deviation was 0% in the X-axis direction and 66% in the Y-axis direction, and the power transmission efficiency η in this case was 91.6%. In the case of the point G8, the positional deviation was 33% in the X-axis direction and 33% in the Y-axis direction, and the power transmission efficiency η in this case was 94.9%.

  As described above, the power transmission efficiency η of the pair of rectangular coils P is 89% or more when the center of gravity of the coil P2 moves to all positions G0 to G8, and the average value of the power transmission efficiency η. Was 93.0%. Therefore, when the center of gravity of the coil P2 is located in a square region S with one side formed by the points G1 to G8 being 30 cm (= 2b), the power transmission efficiency η of the coil P hardly changes and maintains a high value. It is understood that it is possible.

  From the above, since the power transmission system according to the first embodiment includes the pair of rectangular power transmission coils 11 and power reception coils 21 that face each other so that the long sides are orthogonal to each other as a planar pattern, like the coil P, It will be understood that it is possible to suppress a reduction in power transmission efficiency η due to a change in relative position in the planar direction.

-Actual measurement-
Hereinafter, in order to confirm the effectiveness of the above-described simulation result, an actual measurement of the power transmission efficiency η of the power transmission system produced so as to correspond to the simulation model will be described.

  First, a pair of rectangular coils for measurement corresponding to the power transmission coil 11 and the power reception coil, respectively, manufactured so as to have the same configuration as the coil P of the simulation model described above will be described. The actual measurement coil was made of a copper pipe having a diameter of 3 mm in order to prevent an increase in winding resistance due to the skin effect or the like. As shown in FIG. 11, it was confirmed that the measured values of the parameters of the measurement coil are close to the parameters of the simulation model by ANSYS HFSS (registered trademark).

  Next, a description will be given of actual measurement matching circuits respectively corresponding to the power transmission side matching circuit 13 and the power receiving side matching circuit 23, which are manufactured to have the same configuration as the above-described simulation model matching circuit. Here, as in the example shown in FIGS. 7A to 7C, a pair of actual measurement coils whose positional deviations in the X-axis direction are 0%, 33%, and 66%, respectively, are used as a two-terminal pair circuit. The S parameter of the circuit was acquired. The S parameter is converted to Z parameter by MATLAB (registered trademark), and the average value of the power transmission efficiency η when the positional deviation in the X-axis direction is 0%, 33%, and 66%, as in the above simulation model design. The shape of the matching circuit and the value of each element that maximizes the value are determined. A matching circuit for actual measurement was manufactured by soldering chip capacitors and air-core capacitors close to the values determined as described above to the printed circuit board so as to form the determined circuit shape.

The actual measurement of the power transmission efficiency η was performed by acquiring S parameters of a two-terminal pair circuit including a pair of coils and a matching circuit. Specifically, each S parameter when the positional deviation in the X-axis direction of a pair of coils for actual measurement opposed so that the long sides are orthogonal to each other as a planar pattern is 0%, 33%, 66%, The power transmission efficiency η was obtained by obtaining with an analyzer and calculating | S ₂₁ | ² respectively.

  As shown in FIG. 12, the measured value of the power transmission efficiency η of the power transmission system using the rectangular coil according to the first embodiment is as high as approximately 85% or more in the range where the positional deviation is 0% to 66%. The value was maintained. Moreover, the actual measurement value substantially coincided with the simulation result of FIG. As a result, it was confirmed that the rectangular coils that face each other so that the long sides are orthogonal to each other as a planar pattern are less likely to change due to misalignment and realize a power transmission efficiency η that can maintain a high value.

  In addition, the average value of the measured value of the power transmission efficiency η when the positional deviation in the X-axis direction is 0%, 33%, and 66% is 89.6%, which is about 3.5% lower than the simulation result. Met. The reason why the actually measured value is slightly lower than the simulation result may be an error in the shape of the actually measuring coil, a loss in the matching circuit, or the like.

-Coil design-
In the above simulation and actual measurement, the length a of the long side of the coil was 45 cm, and the width b of the short side was 15 cm. At this time, the area ratio of the transmission region R to the entire area of one coil coincides with the aspect ratio 1/3 of the long side and the short side, and the area of the transmission region R is 225 cm ² (= b ² ). Here, a square region S having a side length of 2b as shown by a broken line in FIG. 10 and a side parallel to the long side of the coil is defined. In FIG. 10, when the center of gravity of the other coil that becomes a left-upward rectangle moves on a plane in the square area S of the broken line that has the center of gravity of the right-upward rectangular coil P <b> 1 indicated by a solid line as a center. The area of the transmission region R becomes constant, and high power transmission efficiency η is maintained. If the center of gravity of the coil P1 rising to the right is used as the origin, when there is no position shift in the Y-axis direction, the allowable range of the position shift in the X-axis direction is the maximum, 21.2 cm (= 2 ^1/2 b) in both the positive and negative directions. It becomes the range. Similarly, when there is no positional deviation in the X-axis direction, the allowable range of positional deviation in the Y-axis direction is the maximum, and the range is 21.2 cm (= 2 ^1/2 b) in both the positive and negative directions.

On the other hand, as shown in FIG. 13, if the length of the long side of the coil is a = 40 cm and the width of the short side is b = 20 cm, the area ratio of the transmission region R to the total area of one coil is 1/2. And the area of the transmission region R is 400 cm ² (= b ² ). At this time, the length of one side of the square indicating the range in which the area of the transmission region R is constant is 20 cm (= b). Further, when there is no positional deviation in the Y-axis direction, the allowable range of positional deviation in the X-axis direction is maximized, and the range is 14.1 cm (= b / (2 ^1/2 )) in both positive and negative directions. Similarly, when there is no positional deviation in the X-axis direction, the allowable range of positional deviation in the Y-axis direction is maximized, and the range is 14.1 cm (= b / (2 ^1/2 )) in both positive and negative directions. Thus, when the area ratio is large, the area of the transmission region R defined by the overlapping portions of the coils on the power transmission side and the power reception side is increased and the magnetic coupling is strengthened, so that the coupling coefficient k can be increased. However, a trade-off relationship occurs in which the allowable range of misalignment in the X-axis and Y-axis directions is reduced.

Moreover, as shown in FIG. 14, when the length of the long side of the coil is a = 40 cm and the width of the short side is b = 10 cm, the area ratio of the transmission region R to the total area of one coil is 1/4, The area of the transmission region R is 100 cm ² (= b ² ). At this time, the length of one side of the square indicating the range in which the area of the transmission region R is constant is 30 cm (= 3b). Further, when there is no positional deviation in the Y-axis direction, the allowable range of positional deviation in the X-axis direction is the maximum, and the range is 21.4 cm (= 3b / (2 ^1/2 )) in both positive and negative directions. Similarly, when there is no positional deviation in the X-axis direction, the allowable range of positional deviation in the Y-axis direction is the maximum, and the range is 21.4 cm (= 3b / (2 ^1/2 )) in both the positive and negative directions. When the area ratio is small, the area of the transmission region R becomes small and the coupling coefficient k becomes small, but the allowable range of positional deviation in the X-axis and Y-axis directions can be increased.

  As described above, there is a trade-off relationship between the coupling coefficient k between the coils and the allowable range of positional deviation. Therefore, the area ratio of the coil may be adjusted as appropriate by determining the shape of the coil in consideration of the coupling coefficient k and the design value of the allowable range of displacement.

  As described above, according to the power transmission system according to the first embodiment, the power is transmitted in a state where the rectangular power transmission coil 11 and power reception coil 21 face each other so that the long sides are orthogonal to each other as a planar pattern. Since the data is transmitted, it is possible to suppress a change in the area of the transmission region R defined by the portion where the planar patterns of the coils overlap with each other due to the displacement. Therefore, the power transmission system according to the first embodiment can stabilize the coupling coefficient k between the power transmission coil 11 and the power reception coil 21, and reduce the power transmission efficiency η due to the relative displacement between the coils. Can be suppressed.

  If non-contact power transmission is performed by a magnetic resonance coupling method between rectangular coils arranged to face each other so as to coincide with each other as a plane pattern, the power transmission efficiency is reduced if a positional deviation occurs in the plane direction between the coils. Will drop significantly. For this problem, in addition to adopting a circular or square coil, there are cases in which a coil on the power transmission side larger than the coil on the power reception side or a pattern of a plurality of unit coils arranged in an array is used. However, in this case, there is a possibility that the ground contact area becomes large or the design becomes complicated.

  According to the power transmission system according to the first embodiment, a pair of rectangular coils facing each other are arranged in a simple configuration such that each long side is orthogonal to each other as a planar pattern, and the relative relationship between the coils It is possible to suppress a reduction in power transmission efficiency due to a slight misalignment. Therefore, according to the power transmission system according to the first embodiment, it is possible to easily reduce the size, and in addition to the technical advantage that a complicated design and a large amount of material are unnecessary, a variable impedance matching circuit is not necessary. Therefore, a remarkable technical effect that the manufacturing cost can be reduced can be obtained.

(Second Embodiment)
As shown in FIG. 15, the power transmission system according to the second embodiment of the present invention is a sheet-like power transmission in which a plurality of power transmission coils 11_1, 11_2,..., 11_n (n: an integer of 2 or more) are two-dimensionally arranged. For the sake of convenience, it differs from the power transmission system according to the first embodiment including the power transmission device 10 described as an example with a single power transmission coil 11 in that the device 10A is provided as a power transmission sheet. Since configurations, operations, and effects that are not described in the second embodiment are the same as those in the first embodiment, descriptions thereof are omitted.

  The power transmission device 10A includes, for example, a plurality of power transmission devices 10_1, 10_2,. The plurality of power transmission devices 10_1 to 10_n include a plurality of power transmission coils 11_1 to 11_n, a plurality of power transmission side resonance capacitors 12_1 to 12_n respectively corresponding to the plurality of power transmission coils 11_1 to 11_n, and a plurality of power transmission side matching circuits 13_1 to 13_n. And a plurality of power supply circuits 14_1 to 14_n and a plurality of first control circuits 15_1 to 15_n, respectively. The plurality of power transmission side matching circuits 13_1 to 13_n respectively perform impedance matching of a plurality of resonance circuits each including a plurality of power transmission coils 11_1 to 11_n and a plurality of power transmission side resonance capacitors 12_1 to 12_n. The impedance of each of the plurality of power transmission side matching circuits 13_1 to 13_n is designed so that the power transmission efficiency η from each of the power transmission coils 11_1 to 11_n to the power reception coil 21 is maximized. .

  As shown in FIG. 16, the power transmission system according to the second embodiment is a non-contact power transmission that charges a storage battery that is a power source (secondary power source) that drives a moving body 50 such as an automatic guided vehicle (AGV) for a factory. Applicable to systems and the like. For this reason, in the power transmission system according to the second embodiment, the plurality of power transmission coils 11_1 to 11_n periodically arranged at a constant pitch are provided on the surface of the traveling path on which the moving body 50 is scheduled to travel. A power transmission device 10A including the power transmission coil unit 30A is prepared as a power transmission sheet on the floor of a factory. Then, electric power is sequentially supplied wirelessly from each of the power transmission coils 11_1 to 11_n of the power transmission sheet constituting the power transmission device 10A to the power reception device 20 fixed to the bottom surface (lower surface) of the moving body 50. The power receiving coil unit 40 included in the power receiving device 20 includes a single power receiving coil 21 that is relatively fixed to the bottom surface of the moving body 50 that faces the first plane formed by the plurality of power transmitting coils 11_1 to 11_n in parallel.

  Each of the plurality of first control circuits 15_1 to 15_n has, for example, a plane pattern of the power reception coil 21 corresponding to the power transmission coil corresponding to the moving body 50 traveling on a traveling path in which the plurality of power transmission coils 11_1 to 11_n are arranged. Drive signals are transmitted to the corresponding power supply circuits 14_1 to 14_n in response to being arranged at positions overlapping the planar patterns 11_1 to 11_n. The power supply circuits 14_1 to 14_n are respectively configured from a plurality of corresponding power transmission coils 11_1 to 11_n and a plurality of power transmission side resonance capacitors 12_1 to 12_n according to drive signals transmitted from the corresponding first control circuits 15_1 to 15_n. AC power having a predetermined frequency to be supplied to the power transmission side resonance circuit is generated.

  The plurality of power transmission coils 11_1 to 11_n are wound in the same rectangular shape on the first plane along the first shielding plate 31 and the first magnetic sheet 32 (see FIG. 3), as shown in FIG. Arranged to constitute a power transmission sheet. The plurality of power transmission coils 11_1 to 11_n are arranged in one direction (Y-axis direction) on the first plane to define the travel route of the moving body 50 in a belt shape. Specifically, the power transmission coils 11_1 to 11_n are arranged at equal intervals so as to coincide with the mapping when any pattern of the other power transmission coils 11_1 to 11_n moves in one direction. For this reason, the 1st shielding board 31, the 1st magnetic sheet 32, and the 1st cover 33 with which power transmission coil unit 30A is provided are each extended in the arrangement direction (Y-axis direction) of a plurality of power transmission coils 11_1-11_n. It becomes a belt-like configuration. In addition, the plurality of power transmission coils 11_1 to 11_n are periodically arranged as a planar pattern with a constant pitch, the same orientation, and the same dimensions so that each long side is inclined by 45 ° with respect to the strip-shaped arrangement direction. It constitutes a power transmission sheet.

  As already described, in the power transmission system according to the second embodiment, the power receiving coil unit 40 having the single power receiving coil 21 is fixed to the bottom surface of the moving body 50. The moving body 50 moves in parallel above the first plane along the first plane in which the plurality of power transmission coils 11_1 to 11_n are arranged in the band-shaped region. The power receiving coil 21 is generally a rectangular flat plate, but is located on a second plane parallel to the first plane. The power receiving coil 21 sequentially moves in parallel on the power transmission sheet on which the plurality of power transmission coils 11_1 to 11_n are arranged as the moving body 50 moves on the belt-shaped travel route.

  Similarly to the power transmission system according to the first embodiment, the power receiving coil 21 has a long side longer than the short sides of the power transmission coils 11_1 to 11_n and a short side shorter than the long sides of the power transmission coils 11_1 to 11_n on the second plane. It is wound into a rectangular shape with sides. The power receiving coil 21 has a planar pattern in which the long side is orthogonal to the long side of each of the power transmission coils 11_1 to 11_n and overlaps with the planar pattern of each of the power transmission coils 11_1 to 11_n. Then move. Specifically, the transmission region R defined by the portion where the planar pattern of the power receiving coil 21 sequentially overlaps with the planar pattern of each of the power transmission coils 11_1 to 11_n is the same as the width b1 of the short side of each of the power transmission coils 11_1 to 11_n. From each of the power transmission coils 11_1 to 11_n in a rectangular shape having a first side of the length and a second side adjacent to the first side having the same length as the width b2 of the short side of the power receiving coil 21. Move in parallel while receiving power sequentially without contact.

  Specifically, the orientation of the planar pattern of the power reception coil 21 is selected so that the long side is orthogonal to the long sides of the plurality of power transmission coils 11_1 to 11_n. The selected power receiving coil 21 oriented in this way has a plurality of power transmission coils 11_1 to 11_n in the front-rear direction of the moving body 50 at the bottom of the moving body 50 in which the front-rear direction moving along the second plane is defined. Fixed in a state along the arrangement direction. With such selection of the geometric orientation, as shown in FIG. 16, while the moving body 50 travels above the plurality of power transmission coils 11_1 to 11_n arranged on the travel path, the long side of the power reception coil 21 is always set. Since it is orthogonal to each long side of the plurality of power transmission coils 11_1 to 11_n, even if the position of the moving body 50 is displaced in a direction orthogonal to the traveling path, the state of overlapping with the planar pattern of each power transmission coil 11_1 to 11_n is maintained. Is done.

  FIG. 17 is a diagram focusing on one power transmission coil 11_n among the plurality of power transmission coils 11_1 to 11_n constituting the power transmission sheet. Similarly to the power receiving coil 21 shown in FIG. 3, the power receiving coil 21 moves in parallel while being positioned above the power transmitting coil 11_n. That is, the power receiving coil 21 translates in the direction of the arrow along the arrangement direction (Y-axis direction) shown in FIG. 17, but the plane pattern of the power transmitting coil 11_n and the power receiving coil 21 while the moving body 50 travels. It is possible to increase the time during which the area of the transmission region R defined by the portion where the planar patterns overlap is constant. Furthermore, the power receiving coil 21 is a portion that overlaps with the planar pattern of each of the power transmitting coils 11_1 to 11_n as long as the power receiving coil 21 is displaced within a predetermined range in the width direction of the traveling path, that is, the left-right direction (X-axis direction) of the moving body 50. The area of the defined transmission region R does not change. Therefore, even when the mobile body 50 travels, the change in the area of the transmission region R can be reduced even if the position of the plurality of power transmission coils 11_1 to 11_n is shifted in the left-right direction. The range can be improved.

  As the moving body 50 travels on the travel route on which the plurality of power transmission coils 11_1 to 11_n are arranged, the power reception coil 21 sequentially receives power sequentially from each of the plurality of power transmission coils 11_1 to 11_n. . The power receiving coil 21 charges a storage battery serving as a secondary power source mounted on the moving body 50 with the power sequentially received from each of the plurality of power transmitting coils 11_1 to 11_n. Specifically, when power transmission is started from each of the plurality of power transmission coils 11_1 to 11_n of the sheet-shaped power transmission device 10A on the floor side, the power reception device 20 on the mobile object 50 side receives the power reception side resonance circuit (21, 22), AC power is received and supplied to the load circuit 24 via the power receiving side matching circuit 23. In the load circuit 24, the AC power received by the power receiving coil 21 is converted into a predetermined DC current supplied to the storage battery according to the control of the second control circuit 25, and the DC current is supplied to the storage battery of the moving body 50. As a result, the storage battery is charged.

-Coil design-
Hereinafter, the example of the coil design applicable to the electric power transmission system which concerns on 2nd Embodiment, and its technical effect are demonstrated using the simulation by ANSYS HFSS (trademark) similarly to 1st Embodiment. In the first embodiment, 13.56 MHz is adopted as the resonance frequency, but here, 85 kHz is adopted as an example of the drive frequency of the power feeding device used for an electric vehicle (EV) or the like.

As defined in FIG. 4, a pair of coils P corresponding to each of the power transmission coils 11_1 to 11_n and the power reception coil 21 are wound in a rectangular shape having a long side length a and a short side width b. Define Here, the length a is 52.5 cm, the width b is 22.5 cm, and the distance between the pair of coils is 10 cm. The area of the transmission region R defined by the portion where the pattern of the pair of coils P overlaps is 506.25 cm ² (= b ² ), and the area of the region S increases due to a decrease in frequency compared to the first embodiment. doing.

  As a comparative example of the coil P, a square coil Q having one side having a length c is defined. The length c is 32 cm as in the first embodiment, and the displacements in the X-axis direction are 106 mm and 212 mm, which are the movement distances at 33% and 66% in the first embodiment. It was defined as the distance that the other coil moved parallel to the X axis direction with respect to the coil. The self-inductance of the coil Q is 195 μH which is the same as that of the coil P.

  As shown in FIG. 18, the power transmission efficiency η of the square coil Q according to the comparative example maintains a high value of approximately 90% or more in the range where the positional deviation in the X-axis direction is 0 to 130 mm. As the value changes from 130 mm to 212 mm, it decreases to about 75%. On the other hand, the power transmission efficiency η of the rectangular coil P according to the second embodiment is substantially constant in a state where a high value of approximately 80% or more is maintained in the range where the positional deviation is 0 to 212 mm. In particular, when the positional deviation in the X-axis direction defined in FIG. 16 is 212 mm, the power transmission efficiency η of the coil P according to the second embodiment is about 10% higher than that of the coil Q according to the comparative example. Therefore, it is confirmed that the power transmission efficiency η of the rectangular coil P according to the second embodiment is less likely to change due to misalignment than the square coil Q according to the comparative example, and can maintain a high value. It was done.

  Further, as shown in FIG. 19, output voltages on the power receiving side of the square coil Q according to the comparative example and the rectangular coil P according to the second embodiment were obtained. The output voltage of the coil Q fluctuated about 25V while the positional deviation in the X-axis direction changed from 0 to 212 mm, whereas the output voltage of the coil P fluctuated only about 14V. Thus, it was confirmed that the output voltage of the rectangular coil P is less likely to fluctuate due to misalignment than the square coil Q.

  In addition, when the coil P according to the second embodiment is mounted on an electric vehicle, the power transmission efficiency η due to the displacement of the stop position can be achieved even when performing non-contact power transmission with the electric vehicle stopped. Variations can be prevented.

  As described above, according to the power transmission system according to the second embodiment, each of the planar patterns of the plurality of rectangular power transmission coils 11_1 to 11_n constituting the power transmission sheet and the single power reception coil 21 are provided. Since the plane pattern uses an orientation in which the long sides are opposed to each other so as to be orthogonal to each other, it is possible to suppress a change due to the positional deviation of the area of the transmission region R. Therefore, the power transmission system according to the second embodiment can stabilize the coupling coefficient k between each of the plurality of power transmission coils 11_1 to 11_n and the power reception coil 21 fixed to the moving body 50. For this reason, in the non-contact electric power transmission to AGV for factories etc., reduction of electric power transmission efficiency (eta) resulting from the relative position shift between coils can be suppressed with a simple system configuration. That is, it is possible to continuously transmit power in a stable state from each of the plurality of power transmission coils 11_1 to 11_n to the single power reception coil 21 fixed to the moving body 50 such as AGV.

  In particular, according to the power transmission system according to the second embodiment, the plurality of power transmission coils 11_1 to 11_n constituting the power transmission sheet are periodically arranged at a constant pitch along one direction. The planar pattern of the power receiving coil 21 overlaps the planar pattern of each power transmitting coil 11_1 to 11_n when the power receiving coil 21 mounted on the body 50 is displaced in the left-right direction (direction orthogonal to the traveling direction) of the moving body 50. A change in the transmission region R defined by the portion can be reduced. Therefore, according to the electric power transmission system which concerns on 2nd Embodiment, the tolerance | permissible_range of the position shift of the left-right direction accompanying the driving | running | working of the mobile body 50 of the receiving coil 21 with respect to each power transmission coil 11_1-11_n can be improved.

(Other embodiments)
While embodiments of the present invention have been described as described above, it should not be understood that the description and drawings that form part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, in the first embodiment already described, the power transmission system can be applied to communication devices such as mobile phones and smartphones and other various electronic devices. In this case, for example, by providing a sign defining one direction at a position where the power transmission side device and the power reception side device can be visually recognized, and placing the power reception side device on the power transmission side device so that each sign corresponds, What is necessary is just to make it the coil 11 and the receiving coil 21 oppose orthogonally.

  In the second embodiment, as shown in FIG. 20, the power transmission device 10A includes a plurality of power transmissions periodically arranged along two mutually orthogonal directions of a first plane corresponding to a floor surface of a factory or the like. It may be a power transmission device 10B including a power transmission coil unit 30B having a strip-shaped first traveling path including the coils 11a_1 to 11a_n and a strip-shaped second traveling path including the coils 11b_1 to 11b_n. In the power transmission coil unit 30B, for example, a two-dimensional traveling path of a moving body such as an AGV in a factory can be configured by a first traveling path and a second traveling path that intersects the first traveling path in a T shape. . That is, a plurality of power transmission coils 11a_1 to 11a_n periodically arranged on the first travel route along the first direction Da, and a plurality of coils arranged periodically on the second travel route along the second direction Db. If the electric power transmission sheet | seat provided with power transmission coil 11b_1-11b_m is comprised, the free and stable driving | running | working of the mobile body in a factory can be maintained.

  The plurality of power transmission coils 11a_1 to 11a_n and 11b_1 to 11b_n are respectively installed on the first traveling path along the first direction Da and the second traveling path extending in the second direction Db orthogonal to the first direction Da. As a result, while the moving body 50 on which the power receiving coil 21 is mounted travels straight on the traveling path, the allowable range for the lateral displacement in the straight traveling direction is improved while maintaining high power transmission efficiency η. In particular, even when the moving body 50 changes its traveling direction at a right angle on a T-shaped path as shown in FIG. 20, the change in the area of the transmission region R is suppressed, and the power transmission efficiency from the power transmission sheet is reduced. Reduction of η can be suppressed.

  Further, in the power transmission device 10A according to the second embodiment, as illustrated in FIG. 21, the power supply circuit 14 includes a plurality of power transmission coils 11_1 to 11_n and a plurality of power transmission coils 11_1 to 13_n via the plurality of power transmission side matching circuits 13_1 to 13_, respectively. Wiring between the power supply circuit 14 and the plurality of power transmission side resonance circuits so as to selectively supply an alternating current to any one of the plurality of power transmission side resonance circuits respectively composed of the power transmission side resonance capacitors 12_1 to 12_n. The power transmission device 10 </ b> C including the selector 16 to be switched may be used. The selector 16 includes, for example, a switch connected between the power supply circuit 14 and the plurality of power transmission side matching circuits 13_1 to 13_n, and selectively selects AC power output from the power supply circuit 14 as a plurality of power transmission side matching circuits 13_1. Input to ~ 13_n. The operation of the selector 16 may be controlled by the first control circuit 15.

  Also in this case, as in the second embodiment, in the power transmission coil unit 30C, the plurality of power transmission coils 11_1 to 11_n have a constant pitch such that each long side is inclined by 45 ° with respect to the strip-shaped arrangement direction as a planar pattern. By continuously arranging power transmission sheets with the same orientation and the same dimensions, power can be continuously transmitted to a single power receiving coil 21 fixed to the moving body 50 in a stable state. It is possible to improve the allowable range of the positional deviation in the left-right direction accompanying the traveling of the moving body 50.

  Moreover, in 2nd Embodiment, the mobile body 50 is automatic so that the receiving coil 21 may be arrange | positioned in an appropriate position with respect to several power transmission coil 11_1-11_n according to the beacon signal transmitted from the power transmission apparatus 10 side. You may make it control driving | running | working.

  Furthermore, in the first and second embodiments already described, the power transmission coil 11 and the power reception coil 21 include a power transmission coil 11A including a plurality of unit coil patterns and a plurality of unit coil patterns, as shown in FIG. It may be the power receiving coil 21A. 11 A of power transmission coils are arrange | positioned on a 1st plane, and are included in the inside of the 1st main coil 111 which defines a rectangular-shaped external shape, and the external line which the 1st main coil 111 defines on a 1st plane. In addition, the first main coil 111 has two first subcoils, the first subcoils 112 and 113, which are arranged on both ends in the longitudinal direction.

  The first sub-coils 112 and 113 each have a side that is 1/3 to 1/6 of the length of the long side of the first main coil 111 parallel to the long side of the first main coil 111. It is square. The sides of the first subcoils 112 and 113 in the direction orthogonal to the long side of the first main coil 111 are parallel to the short side of the first main coil 111. For example, the first sub-coils 112 and 113 can be configured as two squares sharing the short side of the first main coil 111 as one side, but are not limited to squares. Further, the first subcoils 112 and 113 may be quadrangular with one side shorter than the short side of the first main coil 111.

  The outline of the first main coil 111 has the same shape as the outline of the power transmission coil 11 in the first and second embodiments, and has four sides of a rectangle having a long side of length a1 and a short side of width b1. And a winding such as a litz wire wound with two turns. The number of turns of the first main coil 111 may be 1 or 3 or more. The first sub-coils 112 and 113 may be wound with a number of turns 1, or may be two or more.

  As shown in FIG. 23, each of the first main coil 111 and the first subcoils 112 and 113 is composed of the same windings wound in the same winding direction. Therefore, the first main coil 111 and the first subcoils 112 and 113 have the same rotation direction of the flowing current. That is, the first main coil 111 and the first subcoils 112 and 113 are connected so as to form magnetic fields in the same direction on the inner sides.

  The power reception coil 21A may have the same geometric structure as the power transmission coil 11A. In other words, the power receiving coil 21A is arranged on the second plane, and is included in the second main coil 211 that defines a rectangular outer shape and the outer line that the second main coil 211 defines on the second plane. As shown in the figure, the second main coil 211 has two second subcoils, the second subcoils 212 and 213, which are arranged at both ends in the longitudinal direction.

  The second subcoils 212 and 213 each have a side that is 1/3 to 1/6 of the length of the long side of the second main coil 211 parallel to the long side of the second main coil 211, respectively. It is square. The sides of the second subcoils 212 and 213 in the direction orthogonal to the long side of the second main coil 211 are parallel to the short side of the second main coil 211. For example, the second subcoils 212 and 213 can be configured by two squares sharing the short side of the second main coil 211 as one side, but are not limited to squares. The second subcoils 212 and 213 may be quadrangular with one side shorter than the short side of the second main coil 211.

  The outline of the second main coil 211 has the same shape as the outline of the power receiving coil 21 in the first and second embodiments, and has four sides of a rectangle having a long side of length a2 and a short side of width b2. And a winding such as a litz wire wound with two turns. The number of turns of the second main coil 211 may be 1 or 3 or more. The second subcoils 212 and 213 may each be a winding wound with a number of turns 1, or may be a winding with two or more turns.

  Similarly to the power transmission coil 11A, each of the second main coil 211 and the second subcoils 212 and 213 includes the same winding wound in the same winding direction. Therefore, the second main coil 211 and the second subcoils 212 and 213 have the same rotation direction of the flowing current. That is, the second main coil 211 and the second subcoils 212 and 213 are connected so as to form magnetic fields in the same direction on the inner sides.

  Similarly to the simulation in the first embodiment, the power transmission efficiency η with respect to the positional deviation between the power transmission coil 11A having the subcoil and the power receiving coil 21A having the subcoil was calculated as shown in FIGS. As in the first embodiment, the long side of the rectangle has a length a1 = a2 = 45 cm, a width b1 = b2 = 15 cm, and a displacement of the XY plane with the center of gravity of the power transmission coil 11A as the origin (in the X-axis direction) The power transmission efficiency η with respect to the positional deviation −100 to 100 and the positional deviation −100 to 100 in the Y axis direction was calculated.

  24 and 25, the power transmission efficiency η between the power transmission coil 11A having the subcoil and the power receiving coil 21A having the subcoil indicated by the hatched square and the data point (“rectangle_change” in FIG. 24 and FIG. 25) It was confirmed that this was improved compared to the coil P according to the first embodiment (indicated as “rectangular” in FIGS. 24 and 25) in which the data points are indicated by white circles. Specifically, the coil P according to the first embodiment exceeds the allowable range in which the area of the transmission region R is maintained when the positional deviation exceeds approximately 66% in both the positive and negative directions in both the X-axis direction and the Y-axis direction. In contrast, the power transmission coil 11A having a secondary coil and the power receiving coil 21A having a secondary coil achieve a high power transmission efficiency η up to about 80% in both the X-axis direction and the Y-axis direction in both positive and negative directions. It was confirmed that it was possible. Therefore, the power transmission coil 11 </ b> A having the sub-coil and the power receiving coil 21 </ b> A having the sub-coil can improve the allowable range of displacement in the XY plane direction.

  In addition to the above, the present invention includes various embodiments and the like that are not described here, such as a configuration in which each configuration described in the above embodiment is arbitrarily applied. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

10, 10A, 10B, 10C Power transmission device 11, 11_1 to 11_n, 11a_1 to 11a_n, 11b_1 to 11b_m, 11A Power transmission coil 12, 12_1 to 12_n Power transmission side resonance capacitor 13, 13_1 to 13_n Power transmission side matching circuit 14, 14_1 to 14_n Power source Circuits 15, 15_1 to 15_n First control circuit 16 Selector 20 Power receiving device 21, 21A Power receiving coil 22 Power receiving side resonance capacitor 23 Power receiving side matching circuit 24 Load circuit 25 Second control circuit 30, 30A, 30B Power transmission coil unit 31 First 1 shielding plate 32 first magnetic sheet 33 first cover 40 power receiving coil unit 41 second shielding plate 42 second magnetic sheet 43 second cover 50 moving body 111 first main coil (main coil)
112, 113 First subcoil (subcoil)
211 Second main coil 212, 213 Second subcoil

Claims (13)

A rectangular power transmission coil disposed on the first plane;
A long side that is arranged on a second plane that is parallel to the first plane and that is perpendicular to the long side of the power transmission coil, and is longer than the short side of the power transmission coil and the long side of the power transmission coil And a rectangular power receiving coil having a short short side, wherein the power receiving coil receives power from the power transmitting coil in a contactless manner. The power transmission coil is:
A main coil defining the rectangular outer shape;
Sides of 1/3 or less of the length of the long side of the outer shape, which are respectively disposed on both ends in the longitudinal direction of the main coil so as to be included in the outer shape on the first plane And the two secondary coils each having a quadrangular shape parallel to each other, wherein the main coil and the two secondary coils are in the same winding direction forming a magnetic field in the same direction. Item 4. The power transmission system according to Item 1. A plurality of rectangular power transmission coils periodically arranged with a constant pitch, the same orientation, and the same dimension along one direction on the first plane;
A long side that is disposed on a second plane that is parallel to the first plane and that is perpendicular to the long side of the power transmission coil and that is longer than the short side of the power transmission coil, and the long side of the power transmission coil A rectangular receiving coil having a shorter short side, wherein the receiving coil sequentially receives power from each of the plurality of transmitting coils by moving in parallel on the first plane. A characteristic power transmission system. Each of the plurality of power transmission coils is
A main coil defining the rectangular outer shape;
Sides of 1/3 or less of the length of the long side of the outer shape, which are respectively disposed on both ends in the longitudinal direction of the main coil so as to be included in the outer shape on the first plane And the two secondary coils each having a quadrangular shape parallel to each other, wherein the main coil and the two secondary coils are in the same winding direction forming a magnetic field in the same direction. Item 4. The power transmission system according to Item 3.   5. The power transmission system according to claim 3, wherein the plurality of power transmission coils are arranged such that each long side is inclined at the same inclination angle with respect to the one direction. 6.   5. The power transmission system according to claim 3, wherein the plurality of power transmission coils are arranged such that each long side is inclined by 45 ° with respect to the one direction.   5. The power transmission system according to claim 3, wherein the power reception coil is fixed to a bottom surface of a moving body that moves in a direction parallel to the second plane so that a front-rear direction is along the one direction. .   The power transmission system according to claim 1, wherein the power reception coil has the same structure as the power transmission coil.   The power transmission system according to claim 1, wherein the power reception coil has the same dimensions as the power transmission coil. A power transmission sheet for transmitting the power to a moving body that travels in parallel above the first plane with power transmitted in a non-contact manner from the first plane,
A set of a plurality of rectangular transmission coils periodically arranged at a constant pitch, the same orientation, and the same dimension along at least one direction on the first plane;
A second plane that is parallel to the first plane is a bottom surface of the moving body, and is a long side that is fixed to the bottom surface and is orthogonal to the long side of the power transmission coil, and is longer than the short side of the power transmission coil The power transmission sheet, wherein the power is sequentially transmitted from each of the plurality of power transmission coils to a rectangular power receiving coil having a long side and a short side shorter than the long side of the power transmission coil. Each of the plurality of power transmission coils is
A main coil defining the rectangular outer shape;
Sides of 1/3 or less of the length of the long side of the outer shape, which are respectively disposed on both ends in the longitudinal direction of the main coil so as to be included in the outer shape on the first plane And the two secondary coils each having a quadrangular shape parallel to each other, wherein the main coil and the two secondary coils are in the same winding direction forming a magnetic field in the same direction. Item 11. The power transmission sheet according to Item 10.   The sheet for power transmission according to claim 10 or 11, wherein the plurality of power transmission coils are arranged such that each long side is inclined at the same inclination angle with respect to the one direction.   Further comprising another set of a plurality of rectangular power transmission coils periodically arranged with a constant pitch, the same orientation, and the same size along another direction orthogonal to the one direction on the first plane. The sheet for electric power transmission according to any one of claims 10 to 12.

Images