JP2014117049A - Non-contact power feeding system, power transmission system, power incoming system, power transmission method, power incoming method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve energy transmission efficiency during non-contact power transmission to a power incoming apparatus from one or more power transmission apparatuses to one or more power incoming apparatuses.SOLUTION: The non-contact power feeding system includes one or more power transmission apparatuses, and one or more power incoming apparatuses that contactlessly receives electric energy with magnetic fields from the power transmission apparatus. Each of the power transmission apparatuses and each of the power incoming apparatuses include power supplies for supplying electric power determined on the basis of impedance information on impedance between antennas of each of the power transmission apparatuses and each of the power incoming apparatuses to the antennas.

Description

  The present invention relates to a contactless power supply system, a power transmission system, a power reception system, a power transmission method, a power reception method, and a program.

  For wireless power feeding, a non-contact power feeding system using magnetic field resonance is known. For example, Patent Literature 1 describes a one-to-one power feeding method between a power transmission device and a power reception device. Further, Patent Document 2 discloses that power is transmitted to a slave unit by laying a coil resonant element on a floor and providing a power transmission path of the coil resonant element to the position of the slave unit. Further, in Patent Document 3, a current is passed from a plurality of master units to the main coil, and a reverse current is supplied to at least one of the other coils to reduce the stray magnetic field, thereby coupling the master unit and the slave unit. It is disclosed to strengthen.

US Patent Application Publication No. 2011/0018361 JP 2012-75304 A Special table 2011-517265 gazette

  By the way, in a room such as a house provided with a plurality of master units, a plurality of wireless home appliances may be used as slave units. In this case, power transmission efficiency from the parent device to the child device may be reduced due to interference between a plurality of parent devices or between the parent device and the child device. However, in Patent Document 2, since a current flows through the coil resonance element on the power transmission path, the ohmic loss is large, and thus high-efficiency energy cannot be transmitted. Further, in Patent Document 3, since the 1-bit on state and off state are controlled, there is a limit to the improvement in efficiency. As described above, there is a problem that the energy transmission efficiency is not sufficient.

  Thus, one embodiment of the present invention has been made in view of the above-described problem, and improves energy transmission efficiency when transmitting power in a non-contact manner from one or more power transmission apparatuses to one or more power reception apparatuses. It is an object of the present invention to provide a non-contact power supply system, a power transmission system, a power reception system, a power transmission method, a power reception method, and a program that enable this.

  (1) One embodiment of the present invention includes one or more power transmission devices and one or more power reception devices that receive energy from the power transmission devices in a contactless manner using a magnetic field, and the sum of the power transmission devices and the power reception devices. Each of the power transmission devices and the power receiving devices has a current or voltage determined based on impedance information related to impedance between the antennas of the power transmission devices and the power reception devices. It is a non-contact electric power feeding system provided with the power supply supplied to an antenna.

  (2) One embodiment of the present invention is the above-described contactless power supply system, in which the current or voltage is determined based on an eigenvector calculated with reference to the impedance information.

(3) One embodiment of the present invention is the contactless power feeding system described above, in which an impedance matrix between antennas or an admittance matrix A having n rows and m columns (n and m are integers) is represented by A [n, m] (A [n, m] is a real number and A [n, m] = A [m, n]), the matrix B is a (Np + Nc) × (Np + Nc) -dimensional Hermitian matrix (provided that Np is the number of power transmission devices, Nc is the number of power reception devices), and when n is a power transmission device and m is a power reception device, the component B [n, m] = A [n, m] / n in n rows and m columns of the matrix B 2 where n represents a power transmitting device and m represents a power receiving device, component B [n, m] = A ^* [n, m] / 2 = A ^* [m, n] / 2 ( ^* represents a complex conjugate) ), When n and m represent a power receiving device, component B [n, m] = Re [A [n, m]], and when n and m represent a power transmitting device When B [n, m] = 0, the square C ² of the matrix C is a Hermitian matrix, and the eigenvector of the matrix D = (C ⁻¹ ) ^to BC ⁻¹ (where − represents transposition) is X The power supplies included in the power transmission devices and the power reception devices supply currents or voltages determined based on the eigenvectors X to the antenna.

  (4) One embodiment of the present invention is the contactless power supply system described above, wherein a current or voltage supplied by the power source is determined in advance with a normalized eigenvector obtained by standardizing the eigenvector X as a reference. It is proportional to the corresponding component of the matrix obtained by multiplying the range vector by the matrix C from the left.

  (5) According to another aspect of the present invention, there is provided the above-described contactless power supply system, wherein a square of a magnitude of a difference between a vector in a predetermined range based on the normalized eigenvector and the normalized eigenvector Is 2-√2 or less.

  (6) One embodiment of the present invention is the contactless power supply system described above, in which the power supplies included in the power transmission devices and the power reception devices are proportional to the components corresponding to the power supply among the components of the matrix CX. A current or voltage is supplied to the antenna.

  (7) One embodiment of the present invention is the above-described contactless power feeding system, wherein a current or voltage proportional to an eigenvector corresponding to a maximum eigenvalue among eigenvalues of the matrix D is supplied to the antenna.

(8) Further, an embodiment of the present invention, there is provided a contactless power supply system described above, the square C ² of the matrix C is the identity matrix.

(9) One embodiment of the present invention is the contactless power feeding system described above, wherein the square C ² of the matrix C is a real part of an impedance matrix or a real part of an admittance matrix.

(10) One embodiment of the present invention is the above-described contactless power feeding system, in which the square C ² of the matrix C is an inductance matrix.

    (11) According to one embodiment of the present invention, a first antenna that supplies energy in a contactless manner with a magnetic field, and a first antenna that discharges electric power by supplying a first amount of electricity to the first antenna. A power transmission system including a plurality of power transmission devices including a power source; a second antenna that receives energy in a non-contact manner by a magnetic field; and a second antenna that absorbs power by supplying a first amount of electricity to the second antenna. A non-contact power feeding system including a power receiving system including a plurality of power receiving devices, wherein the power transmission system is a second electric quantity component in phase with the first electric quantity generated in the first antenna. A first normalization unit that normalizes a value based on the second electrical quantity component extracted by the first extraction unit among a plurality of the power transmission devices, and the first After standardization part 1 standardizes A first power control unit that causes the first power source to generate a second electricity quantity, and the power receiving system extracts a second electricity quantity component in phase with the first electricity quantity generated in the antenna. A second extraction unit, a second normalization unit that normalizes a value based on the second electric quantity component extracted by the second extraction unit among the plurality of power receiving devices, and the second A second power supply control unit that causes the second power source to generate a second electric quantity after the normalization unit normalizes, wherein the first electric quantity is a voltage and the second electric quantity is It is a non-contact electric power feeding system which is an electric current or the said 2nd electric quantity is an electric current, and the said 2nd electric quantity is a voltage.

  (12) One embodiment of the present invention includes a plurality of power transmission devices including an antenna that supplies energy in a contactless manner with a magnetic field, and a power source that discharges power by supplying a first amount of electricity to the antenna. In the power transmission system, an extraction unit that extracts a second electric quantity component in phase with the first electric quantity generated in the antenna, and a plurality of values based on the second electric quantity component extracted by the extraction unit A normalization unit that normalizes between the power transmission devices, and a power supply control unit that causes the power source to generate a second electric quantity after the normalization unit has standardized, wherein the first electric quantity is In the power transmission system, the voltage and the second quantity of electricity are current, or the first quantity of electricity is current and the second quantity of electricity is voltage.

    (13) Further, one embodiment of the present invention includes a plurality of power reception devices including an antenna that receives energy in a non-contact manner by a magnetic field and a power source that absorbs power by supplying a first amount of electricity to the antenna. In the power receiving system, an extraction unit that extracts a second electric quantity component in phase with the first electric quantity generated in the antenna, and a plurality of values based on the second electric quantity component extracted by the extraction unit A normalization unit that normalizes between the power receiving devices, and a power supply control unit that causes the power supply to generate a second electric quantity after the normalization unit normalizes, wherein the first electric quantity is In the power receiving system, the voltage and the second quantity of electricity are current, or the first quantity of electricity is current and the second quantity of electricity is voltage.

  (14) Further, one embodiment of the present invention includes a plurality of power transmission devices including an antenna that supplies energy in a contactless manner with a magnetic field and a power source that discharges power by supplying a first amount of electricity to the antenna. A power transmission method executed by a power transmission system, wherein an extraction unit extracts a second electric quantity component in phase with a first electric quantity generated in the antenna, and a normalization unit extracts the second electric quantity component A procedure for normalizing a value based on the second electric quantity component between the plurality of power transmission devices, and a power supply control unit generates a second electric quantity after the normalization unit normalizes the power supply And the first electric quantity is a voltage and the second electric quantity is a current, or the first electric quantity is a current and the second electric quantity is a voltage. Is the method.

  (15) Further, one embodiment of the present invention includes a plurality of power receiving devices including an antenna that receives energy in a non-contact manner by a magnetic field and a power source that absorbs power by supplying a first amount of electricity to the antenna. A power receiving method executed by the power receiving system, wherein the extraction unit extracts a second electric quantity component in phase with the first electric quantity generated in the antenna, and a normalization unit extracts the second electric quantity component. A procedure for normalizing a value based on the second electric quantity component between the plurality of power receiving devices, and a power source drive unit generates a second electric quantity after the normalization unit normalizes the power source And the first electric quantity is a voltage and the second electric quantity is a current, or the first electric quantity is a current and the second electric quantity is a voltage. Is the method.

  (16) Further, according to one embodiment of the present invention, an extraction step of extracting a second electric quantity component in phase with the first electric quantity generated in the antenna in the computer, and the second step extracted in the extraction step A normalization step for normalizing a value based on an electrical quantity component between a plurality of power transmission devices or between a plurality of power reception devices, and a power source that causes the power source to generate a second electrical quantity after standardization in the normalization step A program for executing the control step, wherein the first electric quantity is a voltage and the second electric quantity is a current, or the first electric quantity is a current and the second electric quantity. A program whose quantity is voltage.

  According to one embodiment of the present invention, energy transmission efficiency can be improved when power is transmitted in a non-contact manner from one or more power transmission devices to one or more power reception devices.

It is a schematic block diagram which shows the structure of the non-contact electric power feeding system in 1st Embodiment. It is a schematic block diagram which shows the structure of the non-contact electric power feeding system in 2nd Embodiment. It is a schematic block diagram which shows the structure of the 1st control part in 2nd Embodiment. It is a schematic block diagram which shows the structure of the 2nd control part in 2nd Embodiment. It is a flowchart which shows an example of the flow of a process of the 1st control part and 2nd control part in 2nd Embodiment. It is a table showing an example of a set of the number of iterations and the vector I _p and the vector I _c.

<First Embodiment>
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic block diagram illustrating a configuration of a non-contact power feeding system 1 in the first embodiment. The non-contact power supply system 1 includes a power transmission system 10 and a power reception system 20. The non-contact power supply system 1 transmits energy from the power transmission system 10 to the power reception system 20.

The power transmission system 10 includes a first power transmission device 11, a second power transmission device 12, and a synchronization signal generation unit 13. Hereinafter, each of the first power transmission device 11 and the second power transmission device 12 is also referred to as a parent device. The first power transmission device 11 includes a power source 111 and an antenna 112. The first power transmission device 11 is a circuit in which a power source 111 and an antenna 112 are connected. The power supply 111 is a current source as an example, generates a current I [1], and supplies the generated current to the antenna 112. The antenna 112 generates a magnetic field around the current supplied from the power source 111. The antenna 112 is an inductor, for example, and its inductance is L.

  The second power transmission device 12 includes a power source 121 and an antenna 122. The second power transmission device 12 is a circuit in which a power source 121 and an antenna 122 are connected. The power supply 121 is a current source as an example, generates a current I [2], and supplies the generated current to the antenna 122. The antenna 122 generates a magnetic field around the current supplied from the power source 121. The antenna 122 is an inductor, for example, and its inductance is L.

The synchronization signal generation unit 13 generates, for example, a first synchronization signal and a second synchronization signal that is delayed by 90 degrees from the first synchronization signal. Then, the synchronization signal generation unit 13 outputs the generated first synchronization signal to the power supply 111 and a power supply 121 described later. In addition, the synchronization signal generation unit 13 outputs the generated second synchronization signal to the power source 211 and a power source 221 described later. In the figure, the signal line from the synchronization signal generator 13 to each power source is indicated by a solid line, but the transmission of the first synchronization signal and the second synchronization signal may be wired or wireless.
The power supply 111 and the power supply 121 of the power transmission system 10 generate a current synchronized with the first synchronization signal input from the synchronization signal generator 13. The power supply 211 and the power supply 221 of the power receiving system 20 generate a current synchronized with the second synchronization signal input from the synchronization signal generation unit 13. Thereby, the phases of the currents of the power supply 211 and the power supply 221 of the power receiving system 20 are delayed by 90 degrees from the phases of the currents of the power supply 111 and the power supply 121 of the power transmission system 10.

The power receiving system 20 includes a first power receiving device 21 and a second power receiving device 22. Hereinafter, each of the first power receiving device 21 and the second power receiving device 22 is also referred to as a slave unit. The first power receiving device 21 includes a power source 211 and an antenna 212. The first power receiving device 21 is a circuit in which a power source 211 and an antenna 212 are connected. The antenna 212 supplies a current induced by a magnetic field generated by the antenna 112 included in the first power transmission device 11 to the power source 211. The antenna 212 supplies a current induced by a magnetic field generated by the antenna 122 included in the second power transmission device 12 to the power supply 211. The antenna 212 is an inductor, for example, and its inductance is L.
The power source 211 receives the current supplied from the antenna 212. The power source 211 is a current source as an example, and generates a current I [3] using a current supplied from the antenna 212. For example, the power supply 211 supplies the generated current I [3] to a load (not shown).

The second power receiving device 22 includes a power source 221 and an antenna 222. The first power receiving device 21 is a circuit in which a power source 221 and an antenna 222 are connected. The antenna 222 causes the current to flow in a direction in which work is performed on the voltage under a voltage induced by the magnetic field generated by the antenna 112 included in the first power transmission device 11, so that the power supply 211 absorbs the power. The antenna 222 is an inductor, for example, and its inductance is L.
The power source 221 is a current source as an example, and generates a current I [4] from a voltage applied to both ends of the antenna 222.

Here, the frequency of all the power supplies is 50 kHz as an example. The inductance L of all the antennas is 157 μH as an example, the winding is 480 mm in diameter on the xy plane, and the number of windings is 10. Here, the y-axis is an axis perpendicular to the drawing, and the plane including the drawing is a plane where y = 0. The y-coordinate of the center of all antenna windings is 0 as an example. All the antennas are wound around the left as an example, and the outer end of the winding is a plus terminal and the inner end of the winding is a minus terminal. Thereby, when the currents of all the current sources become positive, the currents flow in the same direction in all the antennas.
In addition, the mutual inductance can be expressed by a 4 × 4 real symmetric matrix M as an example in all antenna sets. It is. Specifically, the mutual inductance between the antenna 112 and the antenna 122 is M [1,2]. The mutual inductance of the antenna 112 and the antenna 212 is M [1,3]. The mutual inductance between the antenna 112 and the antenna 222 is M [1,4]. The mutual inductance between the antenna 122 and the antenna 212 is M [2, 4]. The mutual inductance of the antenna 122 and the antenna 222 is M [3,4].

The positional relationship between the parent device and the child device is as follows as an example. The distance in the z direction between the main unit antenna and the sub unit antenna is 0.5 m. The distance in the x direction between the antennas of the parent devices and the distance in the x direction between the antennas of the child devices are 0.5 m. The difference in the position in the x direction between the antenna of the master unit and the antenna of the slave unit is x ₁ [m].

Next, a description will be given of a condition in which the maximum energy is supplied to the power receiving apparatus when the transmission energy of the power transmitting apparatus is constant, that is, a condition in which the transmission efficiency is maximized. Here, it is assumed that there are N power transmission devices (N is a positive integer) and M power reception devices (M is a positive integer).
The energy Power [k] released by the power source of the k-th power transmission device (k is a positive integer) is expressed by the following equation (1).

Here, I [k] is a current generated by the power source of the kth power transmission device. The current I ^* [k] is a complex conjugate of the current I [k]. E [k] is a voltage generated by the power source of the kth power transmission device. Let P [k] be a matrix for extracting the k-th component from the vector. Here, the matrix P [k] is a matrix in which only the components of k rows and k columns are 1 and the other components are 0. Here, the expression (1) is expressed by the following expression (2) using the matrix P [k].

Here, the superscript sign represents transposition. P [k] with a symbol “˜” attached above is a matrix obtained by transposing the matrix P [k] ^and is expressed as P [k] ^˜ . Hereinafter, the transposition is represented by a superscript sign. Similarly, I ^* is that attached to the upper code-is a matrix (column vector) I ^* a transposed matrix (row vector) I ^* represents a ^~. I with a symbol ~ is a matrix (row vector) obtained by transposing the matrix (column vector) I. The admittance matrix Y is a matrix whose diagonal component represents the self-admittance of the antenna and whose non-diagonal component represents the mutual admittance between the antennas. The n-row, n-column component of the admittance matrix Y is the self-admittance of the nth antenna. Further, the n-th row and m-th column component of the admittance matrix Y is a mutual admittance between the n-th antenna and the m-th antenna.
The matrix Y with the sign “˜” attached thereto is a matrix obtained by transposing the matrix Y. Code ~ is attached to the upper matrix Y ^* is a transposed matrix matrix Y ^*. Here, the matrix Y ^* is a complex conjugate of the matrix Y. The matrix (column vector) E ^* is a complex conjugate of the matrix (column vector) E.
Since the second term in parentheses on the rightmost side of Equation (2) is a scalar, the value is unchanged even if it is transposed. Therefore, when transposing the second term in parentheses on the rightmost side of equation (2), equation (2) is expressed by the following equation (3).

  Here, the component S [k] of the matrix S included in the rightmost side is defined by the following equation (4).

Here, when representing a matrix code ~ is attached to the top of the matrix E ^* E ^* a ^{~, E * ~ S [n} ] E , since represents the energy power of the n-th power transmitting device to release the child The energy received by the machine is expressed by the following formula (5).

Here, assuming that the portion between E ^{* ˜} and E on the right side of the equation (5) is a matrix B, the matrix B is represented by the following equation (6).

Next, assuming that the n-row m-column component of the matrix B is B [n, m], B [n, m] takes the following values.
(1) When both n and m represent a slave unit, B [n, m] = Re [Y [n, m]].
(2) When both n and m represent a master unit, B [n, m] = 0.
(3) When n represents a parent device and m represents a child device, B [n, m] = Y [n, m] / 2. Here, Y [n, m] is a component of n rows and m columns of the admittance matrix Y.
(4) When n represents a child device and m represents a parent device, B [n, m] = Y [n, m] ^* / 2. Here, Y [n, ^{m] *} is n rows and m columns of a matrix of complex conjugate ^{Y *} of the admittance matrix Y.

In the above example, B [n, m] is determined with reference to the admittance matrix Y, but is not limited thereto, and may be determined with reference to the impedance matrix. Here, the impedance matrix is an inverse matrix of the admittance matrix Y. The impedance matrix is a matrix in which the diagonal component represents the antenna self-impedance and the non-diagonal component represents the mutual impedance between the antennas.
The same applies to the impedance matrix. Since Y [n, m] = Y [m, n], B [m, n] = B [n, m] ^* . Therefore, the matrix B becomes a Hermitian matrix and has a real eigenvalue. As will be described later, if λ is an eigenvalue, -λ is also an eigenvalue.

eigenvectors _{^{[I p ~, I c ~}} ] for eigenvalues lambda ^- (where the sign ~ superscript denotes the transpose) if the eigenvectors for the eigenvalue of -λ is _{^{[I p ~, -I c ~}} ] ^Is . Since these two vectors are eigenvectors having different eigenvalues, they are orthogonal to each other. Therefore, I _p ^{to *} I _p −I _c ^{to *} I _c = 0 holds. _{^{Thus, I p ~ * I p =}} I c ~ * I c holds. Therefore, the following equation (7) is established.

  For this reason, if the following equation (8) holds, equation (9) holds.

From the above, the components of n rows and m columns of the admittance matrix Y between antennas (n and m are integers) are represented by Y [n, m] (Y [n, m] is a real number and Y [n, m] = Y [M, n]). In addition, as described above, the matrix B is a Hermitian matrix of (Np + Nc) × (Np + Nc) dimensions (where Np is the number of power transmission devices, Nc is the number of power reception devices), n is the power transmission device, and m is the power reception device. When representing, the component B [n, m] = Y [n, m] / 2 of the n rows and m columns of the matrix B, and the component B [n, m] = Y ^* when n represents the power transmitting device and m represents the power receiving device ^. [N, m] / 2 = Y ^* [m, n] / 2 (* represents a complex conjugate), and when n and m represent a power receiving device, the component B [n, m] = Re [Y [n, m]], and when n and m represent a power transmission device, component B [n, m] = 0.
In this case, in order to supply the maximum energy to the power receiving apparatus when the transmission energy of the power transmitting apparatus is constant, each power supply operates as follows. Each power supply, a square ^{C 2} of matrix C and Hermitian matrix, the matrix ^{D D = (C -1) ~} BC -1 ( where ~ denotes the transpose) is defined as. In this case, the eigenvalues λ of the matrix D, the sum of the squares of the absolute value of the current flowing through the antenna, since an energy in the case of the square A ² of the matrix A the impedance matrix or an admittance matrix and the matrix A, the maximum eigenvalue Becomes the maximum value of the sum of the squares of the absolute values of the current flowing through the antenna. When the resistance r of each antenna is sufficiently smaller than the maximum eigenvalue, the loss is r times the sum of squares of current. Therefore, each power source can obtain the maximum energy transmission efficiency by generating a current proportional to the normalized eigenvector of the maximum eigenvalue. Therefore, each power supply supplies a current or voltage that is a component included in CX and proportional to the component corresponding to each power supply to the antenna, where X is an eigenvector corresponding to the maximum eigenvalue of matrix D.

  Although the admittance matrix Y has been described in the present embodiment, the matrix B can be determined in the same manner as in the case of the admittance matrix Y using an impedance matrix.

Subsequently, in the first embodiment, the inductance matrix when the difference _{x 1} is 0,0.3,0.5,0.8m position in the x direction between the antennas of the base unit of the antenna and the handset, the matrix B, matrix D, eigenvalue λ of matrix D, and eigenvector of matrix D will be described. Incidentally, the square C ² of matrix C is a unit matrix as an example, C is also an identity matrix. Here, the antenna 112 of the first power transmission device 11 is the first antenna, the antenna 122 of the second power transmission device 12 is the second antenna, the antenna 212 of the third power reception device 21 is the third antenna, and the fourth antenna. The antenna 222 of the power receiving device 22 is referred to as a fourth antenna.

Incidentally, the square C ² of matrix C may be a real part of the real part or the admittance matrix of the impedance matrix. Also, the square C ² of matrix C may be inductance matrix.

<X ₁ = 0 [m]>
First, the differences x ₁ position in the x direction between the antenna of the master unit antenna and the slave unit will be described when the 0 m. In that case, the inductance matrix L is expressed by the following equation (10).

Here, the diagonal component of the inductance matrix L is self-inductance. For example, n rows and n columns of the inductance matrix L are self-inductances of the n-th antenna (where n is an integer from 1 to 4). The off-diagonal component of the inductance matrix L is the mutual inductance between the corresponding inductors. For example, n rows and m columns of the inductance matrix L are mutual inductances of the nth antenna and the mth antenna (here, n and m are integers from 1 to 4).
The matrix D is expressed by the following equation (11).

  A vector U having components of four eigenvalues λ of the matrix D is expressed by the following equation (12).

  A matrix V having each of the four eigenvectors X of the size D of the matrix D as column vectors and the four column vectors as components is expressed by the following equation (13).

  There are four eigenvalues λ of the matrix D, but when the eigenvalue λ of the matrix D takes the maximum value 0.669554, the energy received by the power receiving apparatus is maximized under a constant energy supplied from the power transmitting apparatus. . Since the maximum value of the eigenvalue λ of the matrix D is the second column, the corresponding eigenvector X of the matrix D is the column vector of the second column of the matrix V in Expression (13). The component in the nth row of the matrix V in Expression (13) corresponds to the nth antenna. Each row of the column vector of the second column of the matrix V represents a ratio of currents flowing through the corresponding antenna. Therefore, when I [1]: I [2]: I [3]: I [4] = 0.5j: 0.5j: 0.5: 0.5, the energy supplied from the power transmission device is Under certain conditions, the energy received by the power receiving device is maximized. Here, the current of the power source of each power receiving device is delayed by 90 degrees from the current of each power transmitting device. In addition, the current amplitude is the same for all power supplies and is 0.5.

  In this example, the power source 111 of the first power transmission device 11 passes a current having a value obtained by multiplying 0.5j in 1 row and 2 columns of the matrix V of Expression (13) by a predetermined coefficient K, for example. The power supply 121 of the second power transmission apparatus 12 supplies a current having a value obtained by multiplying 0.5j in 2 rows and 2 columns of the matrix V of the formula (13) by a coefficient K, for example. The power source 211 of the third power receiving device 21 passes a current having a value obtained by multiplying 0.5 in 3 rows and 2 columns of the matrix V of the equation (13) by a coefficient K, for example. For example, the power supply 211 of the fourth power receiving device 21 supplies a current having a value obtained by multiplying 0.5 in 4 rows and 2 columns of the matrix V of Expression (13) by a coefficient K.

<X ₁ = 0.3 [m]>
Subsequently, the difference x ₁ position in the x direction between the antenna of the master unit antenna and the slave unit will be described for the case of 0.3 m. The inductance matrix L is expressed by the following equation (14).

Here, the diagonal component of the inductance matrix L is self-inductance. For example, n rows and n columns of the inductance matrix L are self-inductances of the n-th antenna (where n is an integer from 1 to 4). The off-diagonal component of the inductance matrix L is the mutual inductance between the corresponding inductors. For example, n rows and m columns of the inductance matrix L are mutual inductances of the nth antenna and the mth antenna (here, n and m are integers from 1 to 4).
The matrix D is expressed by the following equation (15).

  A vector U whose components are the four eigenvalues λ of the matrix D is expressed by the following equation (16).

  A matrix V having four magnitude 1 eigenvectors X of the matrix D as column vectors and the four column vectors as components is expressed by the following equation (17).

  When the eigenvalue λ of the matrix D takes the maximum value 0.600802, the energy received by the power receiving apparatus is maximized under a constant energy supplied from the power transmitting apparatus. Since the maximum value of the eigenvalue λ of the matrix D is the second column, the corresponding eigenvector X of the matrix D is the column vector of the second column of the matrix V in Expression (17). The component in the nth row of the matrix V in Expression (17) corresponds to the nth antenna. Each row of the column vector of the second column represents a ratio of currents flowing through the corresponding antenna. Therefore, when I [1]: I [2]: I [3]: I [4] = 0.330: 0.625: −0.625j: −0.330j, the power is supplied from the power transmission apparatus. Under the constant energy, the energy received by the power receiving device is maximized. Here, the current of the power source of each power receiving device is delayed by 90 degrees from the current of each power transmitting device. Further, the amplitude of the power source 111 of the first power transmission device 11 and the amplitude of the power source 221 of the second power reception device 22 are the same. The amplitude of the power source 121 of the second power transmission device 12 and the amplitude of the power source 211 of the first power receiving device 21 are the same.

  In this example, the power supply 111 of the first power transmission apparatus 11 passes a current having a value obtained by multiplying 0.330 of 1 row and 2 columns of the matrix V of Expression (17) by a predetermined coefficient K, for example. The power supply 121 of the second power transmission apparatus 12 supplies a current having a value obtained by multiplying the coefficient K by 2 rows and 2 columns of 0.625 of the matrix V in Expression (17), for example. The power supply 211 of the third power receiving apparatus 21 supplies a current having a value obtained by multiplying −0.625j of 3 rows × 2 columns of the matrix V of Expression (17) by a coefficient K, for example. The power supply 211 of the fourth power receiving device 21 supplies a current having a value obtained by multiplying −0.330j of 4 rows × 2 columns of the matrix V of Expression (17) by a coefficient K, for example.

<X ₁ = 0.5 [m]>
Subsequently, the difference x ₁ position in the x direction between the antenna of the master unit antenna and the slave unit will be described for the case of 0.5 m. The inductance matrix L is expressed by the following equation (18).

Here, the diagonal component of the inductance matrix L is self-inductance. For example, n rows and n columns of the inductance matrix L are self-inductances of the n-th antenna (where n is an integer from 1 to 4). The off-diagonal component of the inductance matrix L is the mutual inductance between the corresponding inductors. For example, n rows and m columns of the inductance matrix L are mutual inductances of the nth antenna and the mth antenna (here, n and m are integers from 1 to 4).
The matrix D is expressed by the following equation (19).

  A vector U whose components are the four eigenvalues λ of the matrix D is expressed by the following equation (20).

  A matrix V having each of the four eigenvectors X having a magnitude of 1 of the matrix D as column vectors and having the four column vectors as components is expressed by the following equation (21).

  When the eigenvalue λ of the matrix D takes the maximum value 0.576371, the energy received by the power receiving apparatus is maximized under a constant energy supplied from the power transmitting apparatus. Since the maximum value of the eigenvalue λ of the matrix D is the second column, the column vector of the second column that is the same as the column number of the maximum value of the eigenvalue λ in the matrix V of Equation (21) corresponds to the maximum value of the eigenvalue λ. This is the eigenvector X of D. The component in the nth row of the matrix V in Expression (21) corresponds to the nth antenna. Each row of the column vector of the second column represents a ratio of currents flowing through the corresponding antenna. Therefore, when I [1]: I [2]: I [3]: I [4] = 0.136j: 0.693j: 0.693: 0.136, the energy supplied from the power transmission apparatus is Under certain conditions, the energy received by the power receiving device is maximized. Here, the current of the power source of each power receiving device is delayed by 90 degrees from the current of each power transmitting device. Further, the amplitude of the power source 111 of the first power transmission device 11 and the amplitude of the power source 221 of the second power reception device 22 are the same. The amplitude of the power source 121 of the second power transmission device 12 and the amplitude of the power source 211 of the first power receiving device 21 are the same.

  In this example, the power source 111 of the first power transmission device 11 passes a current having a value obtained by multiplying a predetermined coefficient K by 0.136j in the first row and the second column of the matrix V in Expression (21), for example. The power supply 121 of the second power transmission apparatus 12 passes a current having a value obtained by multiplying the coefficient K by 2 rows and 2 columns 0.693j of the matrix V of the formula (21), for example. The power source 211 of the third power receiving apparatus 21 passes a current having a value obtained by multiplying the coefficient K by 3 rows and 2 columns of 0.693 in the matrix V of Expression (21), for example. The power source 211 of the fourth power receiving device 21 supplies a current having a value obtained by multiplying the coefficient K by 0.136 of 4 rows and 2 columns of the matrix V of the formula (21), for example.

<X ₁ = 0.8 [m]>
Subsequently, the difference x ₁ position in the x direction between the antenna of the master unit antenna and the slave unit will be described for the case of 0.8 m. The inductance matrix L is expressed by the following equation (22).

Here, the diagonal component of the inductance matrix L is self-inductance. For example, n rows and n columns of the inductance matrix L are self-inductances of the n-th antenna (where n is an integer from 1 to 4). The off-diagonal component of the inductance matrix L is the mutual inductance between the corresponding antennas. For example, n rows and m columns of the inductance matrix L are mutual inductances of the nth antenna and the mth antenna (here, n and m are integers from 1 to 4).
The matrix D is represented by the following equation (23).

  A vector U having the four eigenvalues λ of the matrix D as components is expressed by the following equation (24).

  A matrix V having each of the four eigenvectors X having the size 1 of the matrix D as column vectors and having the four column vectors as components is expressed by the following equation (25).

  When the maximum value of the eigenvalue λ of the matrix D is 0.317939, the energy received by the power receiving apparatus is maximized while the energy supplied from the power transmitting apparatus is constant. Since the maximum value of the eigenvalue λ of the matrix D is the second column, the corresponding eigenvector X of the matrix D is the column vector of the second column of the matrix V in Expression (25). The component in the nth row of the matrix V in Expression (25) corresponds to the nth antenna. Each row of the column vector of the second column represents a ratio of currents flowing through the corresponding antenna. Therefore, when I [1]: I [2]: I [3]: I [4] = − 0.00185j: 0.707104j: 0.707104: −0.00185, the power is supplied from the power transmission apparatus. Under the constant energy, the energy received by the power receiving device is maximized. Further, the amplitude of the power source 111 of the first power transmission device 11 and the amplitude of the power source 221 of the second power reception device 22 are the same. The amplitude of the power source 121 of the second power transmission device 12 and the amplitude of the power source 211 of the first power receiving device 21 are the same.

  In this example, the power source 111 of the first power transmission apparatus 11 passes a current having a value obtained by multiplying −0.00185j in the first row and the second column of the matrix V of Expression (25) by a predetermined coefficient K, for example. The power supply 121 of the second power transmission apparatus 12 supplies a current having a value obtained by multiplying 0.707104j of 2 rows and 2 columns of the matrix V of the formula (25) by a coefficient K, for example. The power supply 211 of the third power receiving apparatus 21 supplies a current having a value obtained by multiplying 0.707104 in 3 rows and 2 columns of the matrix V of Expression (25) by a coefficient K, for example. The power source 211 of the fourth power receiving device 21 passes a current having a value obtained by multiplying −0.00185 of 4 rows × 2 columns of the matrix V of Expression (25) by a coefficient K, for example.

<X ₁ = 1.0 [m]>
Subsequently, the difference x ₁ position in the x direction between the antenna of the master unit antenna and the slave unit will be described for the case of 1.0 m. The inductance matrix L is expressed by the following equation (26).

Here, the diagonal component of the inductance matrix L is self-inductance. For example, n rows and n columns of the inductance matrix L are self-inductances of the n-th antenna (where n is an integer from 1 to 4). The off-diagonal component of the inductance matrix L is the mutual inductance between the corresponding inductors. For example, n rows and m columns of the inductance matrix L are mutual inductances of the nth antenna and the mth antenna (here, n and m are integers from 1 to 4).
The matrix D is expressed by the following equation (27).

  A vector U having four eigenvalues λ of the matrix D as components is expressed by the following equation (28).

  A matrix V having each of the four eigenvectors X of the size D of the matrix D as column vectors and having the four column vectors as components is expressed by the following equation (29).

  When the maximum value of the eigenvalue λ of the matrix D is 0.317939, the energy received by the power receiving apparatus is maximized while the energy supplied from the power transmitting apparatus is constant. Since the maximum value of the eigenvalue λ of the matrix D is the second column, the corresponding eigenvector X of the matrix D is the column vector of the second column of the matrix V in Expression (29). The component in the nth row of the matrix V in Expression (29) corresponds to the nth antenna. Each row of the column vector of the second column represents a ratio of currents flowing through the corresponding antenna. Therefore, when I [1]: I [2]: I [3]: I [4] = − 0.0753j: 0.703j: 0.703: −0.0753, the power is supplied from the power transmission apparatus. Under the constant energy, the energy received by the power receiving device is maximized. The amplitude of the power supply 111 of the first power transmission device 11 and the amplitude of the power supply 221 of the second power reception device 22 are the same. The amplitude of the power source 121 of the second power transmission device 12 and the amplitude of the power source 211 of the first power receiving device 21 are the same.

  In this example, the power source 111 of the first power transmission apparatus 11 passes a current having a value obtained by multiplying −0.07553j in the first row and the second column of the matrix V in Expression (29) by a predetermined coefficient K, for example. The power supply 121 of the second power transmission apparatus 12 supplies a current having a value obtained by multiplying, for example, 0.703j of 2 rows and 2 columns of the matrix V of Expression (29) by a coefficient K. The power source 211 of the third power receiving apparatus 21 passes a current having a value obtained by multiplying 0.703 in 3 rows and 2 columns of the matrix V of the formula (29) by a coefficient K, for example. The power source 211 of the fourth power receiving device 21 passes a current having a value obtained by multiplying −0.0753 of 4 rows × 2 columns of the matrix V of Expression (29) by a coefficient K, for example.

As described above, the contactless power supply system 1 according to the first embodiment includes two power transmission devices and two power reception devices that receive energy from the two power transmission devices in a contactless manner using a magnetic field. Each power transmission device and each power reception device includes an antenna and a power source that supplies the antenna with power determined based on impedance information that is information related to impedance between the antennas. Here, the impedance information includes impedance and admittance. More specifically, the power is determined based on an eigenvector calculated with reference to impedance information.
Thereby, each power supply can supply an appropriate electric current or voltage to the antenna according to the positional relationship between the antennas, so that transmission efficiency can be improved.

More specifically, an impedance matrix or admittance matrix between antennas is defined as a matrix A, and an n-by-m component (n and m are integers) of the matrix A is represented by A [n, m] (A [n, m] is a real number. Yes, when A [n, m] = A [m, n]), the matrix B is a Hermitian matrix of (Np + Nc) × (Np + Nc) dimensions (where Np is the number of power transmission devices and Nc is the number of power reception devices) Number), when n represents a power transmitting device and m represents a power receiving device, the component B [n, m] = A [n, m] / 2 of n rows and m columns of the matrix B is set, where n is the power transmitting device and m is the power receiving device. Component B [n, m] = A × [n, m] / 2 = A × [m, n] / 2, and component B [n, m] = Re when n and m represent a power receiving device [A [n, m]], where n and m represent power transmission devices, the component B [n, m] = 0, and the square C ² of the matrix C is Hermitian matrix When the eigenvector of the matrix D = (C ⁻¹ ) ^to BC ⁻¹ (where “−” represents transposition) is X, the power sources included in each power transmission device and each power reception device are components of the matrix CX, respectively. The power supply supplies a current or voltage proportional to the corresponding component to the antenna to which the power supply is connected.
Thereby, each power supply can supply an appropriate electric current or voltage to the antenna according to the positional relationship between the antennas, so that transmission efficiency can be improved.

  At this time, each power supply supplies, as an example, a current or voltage proportional to a normalized eigenvector corresponding to the maximum eigenvalue among eigenvalues of the matrix D to the antenna to which the power supply is connected. Thereby, according to the positional relationship between the antennas, the current supplied to the antenna of the power receiving device can be maximized under a constant energy supplied from the power transmitting device, so that the transmission efficiency can be maximized. .

  In the first embodiment, as an example, the non-contact power feeding system 1 includes two power transmission devices and two power receiving devices, but the present invention is not limited to this. The non-contact power supply system 1 may include one power transmission device or three or more power transmission devices. The non-contact power feeding system 1 may include one or three or more power receiving devices. That is, the non-contact power feeding system 1 may include one or more power transmission devices and one or more power reception devices.

In this embodiment, the power supply generates a current proportional to the eigenvector corresponding to the maximum eigenvalue of the matrix D. However, the power supply is not limited to this, and the power supply is derived from the normalized eigenvector corresponding to the maximum eigenvalue of the matrix D. A current proportional to a vector shifted by a predetermined shift amount Δ may be generated. Hereinafter, the maximum allowable deviation amount Δmax will be described.
_{f = [f 1, ...,} f Np + Nc] ~ a size 1 _{vector, F = [F 1, ...} , F Np + Nc] ~ a size 1 eigenvector (hereinafter, also referred to as the normalized eigenvectors) When to eigenvectors Is defined by the following equation (30).

  Here, n is an index, Np is the number of power transmission devices, and Nc is the number of power reception devices. Since | f | = 1 and | F | = 1, these two vectors f and F are on the spherical surface of an Np + Nc-dimensional sphere having a radius of 1. When the eigenvector F is the eigenvector of the maximum eigenvalue λ, when the eigenvector F ′ having the eigenvalue −λ is mixed into the vector f, the secondary form of the matrix defined by the following equation (31) is the smallest.

  At this time, when the mixing amount of the eigenvector F ′ into the vector f exceeds half, that is, the vector f is expressed by f = (1 / √2) F + aF ′ (where | a |> 1 / √2). , The quadratic form of the matrix represented by equation (31) is smaller than zero. The deviation amount Δ when the mixing amount of the eigenvector F ′ into the vector f is half is set as the maximum allowable deviation amount Δmax. In this case, since f = (√2) / 2 (F + F ′), the maximum deviation amount Δmax is | f−F | = | (1 / √2) F + (1 / √2) F′−F | = √ (2−√2) = √0.586 = 0.766. From this, the current value or voltage value generated by each power supply is proportional to each component of the matrix obtained by multiplying the vector in a predetermined range with the normalized eigenvector F as a reference by the matrix C from the left. The magnitude of the difference vector between the vector in a predetermined range with respect to the normalized eigenvector F and the normalized eigenvector F is 0.766 (= √ (2−√2) = the corresponding component of the normalized eigenvector F. √ (0.586)) times or less. In other words, the square of the magnitude of the vector of the difference between the vector in a predetermined range based on the normalized eigenvector and the normalized eigenvector is 2-√2 or less.

<Second Embodiment>
Next, the second embodiment will be described. FIG. 2 is a schematic block diagram showing the configuration of the non-contact power feeding system 2 in the second embodiment. The same elements as those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted. The non-contact power supply system 2 includes a power transmission system 30 and a power reception system 40. Moreover, since the positional relationship of each antenna with which the power transmission system 30 and the power receiving system 40 are provided is the same as that of the first embodiment, the description thereof is omitted. Further, since the inductance and mutual inductance of each antenna are the same as those in the first embodiment, description thereof is omitted.

  The power transmission system 30 includes a first power transmission device 31, a second power transmission device 32, a first control unit 33, and a synchronization signal generation unit 13. Hereinafter, each of the first power transmission device 31 and the second power transmission device 32 is also referred to as a parent device. The first power transmission device 31 has a voltmeter 113 added as compared to the first power transmission device 11 of the first embodiment shown in FIG. The voltmeter 113 measures the voltage across the antenna 112, and outputs first voltage information indicating the voltage obtained by the measurement to the first control unit 33.

The second power transmission device 32 has a voltmeter 123 added as compared to the second power transmission device 12 of the first embodiment shown in FIG. The voltmeter 123 measures the voltage across the antenna 122 and outputs second voltage information indicating the voltage obtained by the measurement to the first control unit 33.
For example, the first control unit 33 refers to the voltage indicated by the first voltage information input from the voltmeter 113 and the voltage indicated by the second voltage information input from the voltmeter 123, and the current of the power supply 111 and the power supply 121 current is controlled. Details of the processing of the first control unit 33 will be described later.

  The power receiving system 40 includes a first power receiving device 41, a second power receiving device 42, and a second control unit 43. Hereinafter, each of the first power receiving device 41 and the second power receiving device 42 is also referred to as a slave unit. The first power receiving device 41 is obtained by adding a voltmeter 213 as compared to the first power receiving device 21 of the first embodiment shown in FIG. The voltmeter 213 measures the voltage at both ends of the antenna 212 and outputs third voltage information indicating the voltage obtained by the measurement to the second control unit 43.

The second power receiving device 42 is obtained by adding a voltmeter 223 as compared to the second power receiving device 22 of the first embodiment shown in FIG. The voltmeter 223 measures the voltage across the antenna 222 and outputs fourth voltage information indicating the voltage obtained by the measurement to the second control unit 43.
For example, the second control unit 43 refers to the voltage indicated by the third voltage information input from the voltmeter 213 and the voltage indicated by the fourth voltage information input from the voltmeter 223, and the current of the power supply 211 and the power supply The current of 221 is controlled. Details of the processing of the second control unit 43 will be described later.

  FIG. 3 is a schematic block diagram showing the configuration of the first control unit 33 in the second embodiment. The first control unit 33 includes a first extraction unit (extraction unit) 331, a first normalization unit (normalization unit) 332, and a first power supply control unit (power supply control unit) 333. The first extraction unit 331 acquires first voltage information from the voltmeter 113. The first extraction unit 331 extracts a current component in phase with the voltage indicated by the acquired first voltage information. Further, the first extraction unit 331 acquires second voltage information from the voltmeter 123. The first extraction unit 331 extracts a current component in phase with the voltage indicated by the acquired second voltage information. The first extraction unit 331 performs the above processing by the following processing, for example. For example, the first extraction unit 331 acquires a voltage vector whose components are a voltage applied to the antenna 112 and a voltage applied to the antenna 122, and extracts a current component in phase with the voltage vector.

  The first normalization unit 332 adds, to each current component extracted by the first extraction unit 331, a value obtained by multiplying the current value currently generated by the power supply corresponding to the current component by a positive constant. And the 1st normalization part 332 normalizes the value obtained by adding between power transmission apparatuses. At this time, the first normalization unit 332, for example, the sum of squares of the currents generated by the power supply 111 and the power supply 121 is the same as the sum of squares of the currents generated by the power supply 211 and the power supply 221 of the power receiving system 40 (for example, 0 .5) and standardize.

  The first power supply control unit 333 controls the power supply 111 and the power supply 121 so that the power supply 111 and the power supply 121 generate the current after the first normalization unit 332 normalizes. Thereafter, the first extraction unit 331, the first normalization unit 332, and the first power supply control unit 333 repeat the above-described processing. In this way, the first control unit 33 repeats the above-described processing, thereby corresponding to the current after normalization by the first normalization unit 332 to the maximum eigenvalue of the matrix D described in the first embodiment. It can be gradually converged to the eigenvector. However, first, the first power supply control unit 333 generates initial currents predetermined for the power supply 111 and the power supply 121 before the first extraction unit 331 extracts a current component. The power supply 111 and the power supply 121 are controlled to do so. The initial current of the power supply 111 is 0.25 A, for example, and the initial current of the power supply 121 is −0.5 A, for example.

FIG. 4 is a schematic block diagram illustrating a configuration of the second control unit 43 in the second embodiment. The second control unit 43 includes a second extraction unit (extraction unit) 431, a second normalization unit (normalization unit) 432, and a second power supply control unit (power supply control unit) 433.
The second extraction unit 431 has the same function as the first extraction unit. The second extraction unit 431 acquires third voltage information from the voltmeter 213. The second extraction unit 431 extracts a current component in phase with the voltage indicated by the third voltage information. Further, the second extraction unit 431 acquires the fourth voltage information from the voltmeter 223. The second extraction unit 431 extracts a current component in phase with the voltage indicated by the acquired fourth voltage information. The second extraction unit 431 performs the above processing by, for example, the following processing. The second extraction unit 431 acquires a voltage vector whose components are a voltage applied to the antenna 212 and a voltage applied to the antenna 222, and extracts a current component in phase with the voltage vector.

  The second normalization unit 432 adds, to each current component extracted by the second extraction unit 431, a value obtained by multiplying the current value currently generated by the power supply corresponding to the current component by a negative constant. And the 2nd normalization part 432 normalizes the value obtained by adding between power transmission apparatuses. At this time, the second normalization unit 432, for example, has the same sum of squares of the currents generated by the power supply 211 and the power supply 221 as the sum of squares of the currents generated by the power supply 111 and the power supply 121 of the power transmission system 30 (for example, 0 .5) and standardize.

  The second power supply control unit 433 controls the power supply 211 and the power supply 221 so that the power supply 211 and the power supply 221 generate the current after the second normalization unit 432 standardizes. Thereafter, the second extraction unit 431, the second normalization unit 432, and the second power supply control unit 433 repeat the above-described processing. In this way, the second control unit 43 repeats the above-described processing, thereby causing the current after the second normalization unit 432 to normalize to correspond to the maximum eigenvalue of the matrix D described in the first embodiment. Can be gradually converged to the eigenvector. However, first, the second power supply control unit 433 generates initial currents that are predetermined for the power supply 211 and the power supply 221 before the second extraction unit 431 extracts the current component. The power supply 211 and the power supply 221 are controlled. The initial current of the power supply 211 is, for example, a current delayed by 90 degrees from the power supply 111 with an execution value of −1A. The initial current of the power source 221 is, for example, a current that is -0.5 A and delayed by 90 degrees from the power source 121, for example.

<Principle of processing of first control unit 33 and second control unit 43>
Subsequently, the principle that the updated current can be gradually converged to the eigenvector corresponding to the maximum eigenvalue of the matrix D by repeatedly updating the current value in the first control unit 33 and the second control unit 43. explain.

  When the resistance component of the circuit of the power transmission device and the power reception device is sufficiently small, the resistance component that is the real part of the impedance can be ignored, and thus the impedance matrix A is expressed by the following equation (32). Here, the subscript p represents the parent device and c represents the child device.

Here, Z _pp in mutual impedance between the master unit, Z _pc is the mutual impedance between the master unit and the slave unit. Symbol _{Z pc} ^~ sign ~ is attached to the top of the Z _{pc is} the transpose of _{Z pc.} Z _cc is the mutual impedance between the slave units. _Xpp is the mutual reactance between the parent devices. X _cc is the mutual reactance between the slave units. X _pc is a mutual reactance between the parent device and the child device. Here, X _pp , X _pc , and X _cc are execution columns.
At this time, the matrix B is expressed by the following equation (33).

As in the case C ² is represented by the following formula (34), the slave unit, if the component between the master unit 0, the master unit to each other as the matrix D can be expressed by the following equation (35) And the component between the slave units become zero.

  When the matrix C is a unit matrix, the matrix D is represented by the following formula (36).

  When the eigenvalue of the matrix D is λ, the following equation (37) is established.

Here, [I _p , I _c ] ^˜ are eigenvectors of the matrix D. I _p is a vector whose component is the current flowing through each parent unit among the eigenvectors of the matrix D. I _c is a vector whose component is a current flowing through each slave unit among the eigenvectors of column D. Further, when this equation (37) is decomposed, it is expressed by the following equation (38).

  When each expression of Expression (37) is multiplied by a vector obtained by transposing the expression and taking a complex conjugate, it is expressed by the following Expression (39).

The vector I _c is calculated from the left equation toward the equation (38), and the calculated vector I _c is substituted into the right equation. The vector I _p is calculated from the right equation toward the equation (38), and the calculated vector I _p is substituted into the left equation. Then, the following equation (40) is established.

When the formula (40) is multiplied by I _c ^{* ˜} and I _p ^{* ˜} from the left, the following formula (41) is established. _{Here, I} ^{c * ~} intended to code-is attached on the _I ^{c *,} is a vector obtained by transposing the complex conjugate _I ^{c *} of _{I c.} I _p ^{* ~} intended to code-is attached on the _I ^{p *,} is a vector obtained by transposing the complex conjugate _I ^{p *} of _{I p.}

  From the equations (40) and (41), the following equation (42) is established.

  This indicates that the sum of squares of the current components of the parent device included in the eigenvector of the matrix D is equal to the sum of squares of the current components of the child devices included in the eigenvector of the matrix D. Therefore, it is shown that the current normalization processing by the first normalization unit 332 can be performed between the parent device components. Similarly, it is shown that the current normalization processing by the second normalization unit 432 can be performed between the child device components. This indicates that it is not necessary to exchange information between the master unit and the slave unit for standardization.

  When equation (37) is established, the following equation (43) is established.

Therefore, if λ is an eigenvalue, −λ is also an eigenvalue. That is, there are two eigenvalues having the maximum absolute value of ± λ. When [I _p , I _c ] ^˜ is an arbitrary vector other than 0 (where “ ^˜” represents transposition), the following equation (44) converges to the eigenspace in which the eigenvalue having the maximum absolute value appears.

On the other hand, if α is a positive number, the eigenvalue of the following equation (45) asymptotically approaches the maximum (α + λ) ⁿ , and [I _p , I _c ] ^˜ converges to the eigenvector corresponding to the positive maximum eigenvalue.

Therefore, [I _p , I _c ] ^˜ can be converged to the eigenvector corresponding to the maximum positive eigenvalue of the matrix represented by the following equation (46) by the processing of the flowchart of FIG.

Next, FIG. 5 is a flowchart illustrating an example of a processing flow of the first control unit 33 and the second control unit 43 in the second embodiment.
(Step S101) The first control unit 33 passes a current indicated by the vector _Ip through the circuit. At this time, all the currents included in the vector _Ip are in phase.
(Step S102) in parallel with the step S101, the second control unit 43 flows in the circuit current indicated by the vector _{I c.} At this time, current included in the vector I _c are all the same phase. Further, the phase of the current included in the vector I _c is delayed by 90 ° from the current included in the vector I _p .
(Step S103) The first control unit 33 acquires the voltage vector V _p consisting of a voltage component according to the antenna, to extract a current component of the voltage vector V _p in phase.
(Step S104) in parallel with the step S103, the second control unit 43 acquires the voltage vector V _c comprising a voltage component according to the antenna, to extract a current component of the voltage vector V _c and phase.
(Step S105) The first control unit 33 adds the value obtained by multiplying a positive constant to the components of the vector I _p to the components of the vector I _p. And the 1st control part 33 standardizes the value obtained by adding in a subunit | mobile_unit.
(Step S106) in parallel with the step S105, the second control unit 43 is a component of the vector _{I c,} adds the value obtained by multiplying a positive constant to the components of the vector _{I c.} And the 2nd control part 43 normalizes the value obtained by adding in a subunit | mobile_unit.
(Step S107) The first control unit 33 sets the vector component obtained by the normalization as the next vector _Ip , returns to the process of step S101, and repeats the processes after step S101.
(Step S108) in parallel with the step S107, the second control unit 43 is a component of the vector obtained by the normalized and the next vector _{I c,} the process returns to step S102, step S102 and repeats the subsequent processing. Above, description of this flowchart is complete | finished.

  In this way, the non-contact power supply system 2 repeats the process after step S101 and the process after step S102 while supplying power, thereby corresponding each current value generated by each power source to the maximum eigenvalue of the matrix D. It can be approximated to each component of the eigenvector. As a result, even if the positional relationship between the power transmission devices, the positional relationship between the power reception devices, or the positional relationship between the power transmission device and the power reception device is changed over time, each power source is generated following the change. Update each current value. As a result, the non-contact power feeding system 2 can bring each current value generated by each power source closer to each component of the eigenvector corresponding to the maximum eigenvalue of the matrix D in the changed positional relationship, so that the positional relationship is the time Even if it is changed over time, the energy transmission efficiency can be improved.

  In the non-contact power supply system 2, the first control unit 33 and the second control unit 43 are configured so that each current value generated by each power source is an eigenvector corresponding to the maximum eigenvalue of the matrix D by the update process described above. When each component falls within a range (for example, each component ± ΔI of the eigenvector, where ΔI is a predetermined value), the current value may be caused to flow to each power source.

Then, when the difference x ₁ in the x-direction position between the antennas of the base unit of the antenna and the handset is 0.3, an example of a result obtained by repeating the eigenvectors in the process described above with reference to FIG. 6 explain. Figure 6 is a table showing an example of a set of the number of iterations and the vector I _p and the vector I _c. In the figure, in the example of the figure, the vector I _p is composed of a component corresponding to the current of the power source 111 and a component corresponding to the current of the power source 121. In the example shown in the figure, the vector I _c is composed of a component corresponding to the current of the power source 211 and a component corresponding to the current of the power source 221.

Here, as shown in the first embodiment, when the difference x ₁ in x-direction position between the antennas of the base unit of the antenna and the handset is 0.3, the maximum eigenvalue of the matrix D of 0.60 and the corresponding eigenvectors [0.330365,0.625187, -0.625187j, ^-0.330365j] is ^~. Each component of the vector _Ip gradually approaches the first and second column components of the eigenvector as the number of iterations increases. Each component of the vector I _c are respectively approached gradually every component and the number of iterations to a component of the fourth column of the third column of the eigenvector is increased. Therefore, the vector I _p and the vector I _c converge to the eigenvector corresponding to the maximum eigenvalue of the matrix D by the above-described iterative processing. Here, the initial value is [0.2,0.4, -0.8j, ^-0.4j] a ^~, the absolute value of the vector of the difference between this vector and eigenvectors is 0.79. This value is out of the range of the above-described maximum deviation amount Δmax (= 0.766) or less.

  As described above, the power transmission system 30 in the second embodiment includes the first power transmission device 31 and the second power transmission device 32. The first power transmission device 31 includes an antenna 112 that supplies energy in a non-contact manner by a magnetic field, and a power source 111 that supplies power to the antenna 112. The second power transmission device 32 includes an antenna 122 that supplies energy in a contactless manner with a magnetic field, and a power source 121 that supplies power to the antenna 122.

  In the power transmission system 30, the first extraction unit 331 extracts a current component having the same phase as the voltage applied to the antenna 112 and the antenna 122. The first normalization unit 332 normalizes the value based on the current component extracted by the first extraction unit 331 between the first power transmission device 31 and the second power transmission device 32. The first power supply control unit 333 causes the power supply 111 and the power supply 121 to generate currents after the first normalization unit 332 normalizes. The power transmission system 30 repeats the processes of the first extraction unit 331, the first normalization unit 332, and the first power supply control unit 333 described above. Accordingly, the first control unit 33 can make the current after normalization approach the corresponding component included in the eigenvector corresponding to the maximum eigenvalue of the matrix D.

  The power receiving system 40 includes a first power receiving device 41 and a second power receiving device 42. The first power receiving device 41 includes an antenna 212 that receives energy in a non-contact manner by a magnetic field, and a power source 211 that supplies power to a load (not shown) based on the energy received by the antenna 212. The power receiving system 40 includes a first power receiving device 41 and a second power receiving device 42. The second power receiving device 42 includes an antenna 222 that receives energy in a non-contact manner by a magnetic field, and a power source 221 that supplies power to a load (not shown) based on the energy received by the antenna 222.

  Further, in the power receiving system 40, the second extraction unit 431 extracts a current component in phase with the voltage applied to the antenna 212 and the antenna 222. The second normalization unit 432 normalizes the value based on the current component extracted by the second extraction unit 431 between the first power receiving device 41 and the second power receiving device 42. The second power supply control unit 433 causes the power supply to generate a current after the second normalization unit 432 normalizes. The power receiving system 40 repeats the processes of the second extraction unit 431, the second normalization unit 432, and the second power supply control unit 433 described above. Accordingly, the second control unit 43 can make the current after normalization approach the corresponding component included in the eigenvector corresponding to the maximum eigenvalue of the matrix D.

  The power transmission system 30 and the power reception system 40 can make the currents of the power sources 111, 121, 212, and 222 approach each component of the eigenvector corresponding to the maximum eigenvalue of the matrix D by performing the above-described repeated processing in the same cycle. . From another viewpoint, the power transmission system 30 and the power reception system 40 can make the ratio of the currents of the power sources 111, 121, 212, and 222 approach the ratio of the component of the eigenvector corresponding to the maximum eigenvalue of the matrix D. As the current ratio of each power source approaches the ratio of the eigenvector component corresponding to the maximum eigenvalue of the matrix D, the energy transmission efficiency improves. Therefore, the power transmission system 30 and the power reception system 40 perform the above-described repetitive processing in the same cycle. Thus, energy transmission efficiency can be gradually improved.

  In the first embodiment, as an example, the non-contact power supply system 2 includes two power transmission devices and two power reception devices, but is not limited thereto. The non-contact power supply system 1 may include one power transmission device or three or more power transmission devices. Further, the non-contact power feeding system 2 may include one power receiving device or three or more power receiving devices. That is, the non-contact power supply system 2 may include one or more power transmission devices and one or more power reception devices.

In each embodiment, the power transmission system 10 or 30 includes the synchronization signal generation unit 13. However, the configuration is not limited thereto, and the power reception system 20 or 40 may include the synchronization signal generation unit 13.
Also, a program for executing each process of the first control unit 33 or the second control unit 43 of the second embodiment is recorded on a computer-readable recording medium, and the program recorded on the recording medium The above-described various processes related to the first control unit 33 or the second control unit 43 may be performed by causing the computer system to read and execute the program.

  Here, the “computer system” may include an OS and hardware such as peripheral devices. Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used. The “computer-readable recording medium” means a flexible disk, a magneto-optical disk, a ROM, a writable nonvolatile memory such as a flash memory, a portable medium such as a CD-ROM, a hard disk built in a computer system, etc. This is a storage device.

  Further, the “computer-readable recording medium” refers to a volatile memory (for example, DRAM (Dynamic) in a computer system serving as a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. Random Access Memory)) that holds a program for a certain period of time is also included. The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, a specific structure is not restricted to this embodiment. Each configuration in each embodiment, a combination thereof, and the like are examples, and the addition, omission, replacement, and other changes of the configuration can be made without departing from the spirit of the present invention. Further, the present invention is not limited by the embodiments, and is limited only by the scope of the claims.

DESCRIPTION OF SYMBOLS 1, 2 Non-contact electric power feeding system 10, 30 Power transmission system 11, 31 1st power transmission apparatus 12, 32 2nd power transmission apparatus 13 Synchronization signal generation part 20, 40 Power receiving system 21 1st power receiving apparatus 22 2nd power receiving apparatus 33 first control unit 43 second control unit 111 power source 112 antenna 113, 123, 213, 223 voltmeter 121 power source 122 antenna 211 power source 212 antenna 221 power source 222 antenna 331 first extraction unit (extraction unit)
332 First standardization unit (standardization unit)
333 1st power supply control part (power supply control part)
431 Second extraction unit (extraction unit)
432 Second standardization unit (standardization unit)
433 Second power supply control unit (power supply control unit)

Claims (16)

A non-contact power feeding system including one or more power transmission devices and one or more power reception devices that receive energy from the power transmission device in a contactless manner by a magnetic field, and a total of the power transmission devices and the power reception devices is three or more Because
Each power transmission device and each power receiving device
A non-contact power feeding system including a power source that supplies current or voltage determined based on impedance information related to impedance between antennas of each power transmitting device and each power receiving device to the antenna.   The contactless power feeding system according to claim 1, wherein the current or voltage is determined based on an eigenvector calculated with reference to the impedance information. The impedance information is an impedance matrix or an admittance matrix between the antennas,
The impedance matrix between the antennas or the admittance matrix is a matrix A, and n rows and m columns of the matrix A (n and m are integers) are A [n, m] (A [n, m] is a real number and A [ n, m] = A [m, n]), the matrix B is a (Np + Nc) × (Np + Nc) -dimensional Hermitian matrix (where Np is the number of power transmission devices and Nc is the number of power reception devices), n Component B [n, m] = A [n, m] / 2 of matrix B when n represents a power transmission device and m represents a power reception device, and component when n represents a power transmission device and m represents a power reception device B [n, m] = A ^* [n, m] / 2 = A ^* [m, n] / 2 (* represents a complex conjugate), and when n and m represent a power receiving device, component B [n, m] = Re [A [n, m]], and when n and m represent a power transmission device, the component B [n, m] = 0 and the square C ^{2 of the} matrix C is When the eigenvectors of the matrix D = (C ⁻¹ ) ^to BC ⁻¹ (˜ represents transposition) are X, the power sources included in each power transmission device and each power reception device are determined based on the eigenvector X. The non-contact electric power feeding system as described in any one of Claim 1 or 2 which supplies the said electric current or voltage to the said antenna.   The current or voltage supplied by the power source is proportional to a corresponding component of a matrix obtained by multiplying a vector in a predetermined range based on a normalized eigenvector obtained by standardizing the eigenvector X by the matrix C from the left. The contactless power feeding system according to claim 3.   5. The wireless power feeding system according to claim 4, wherein a square of the magnitude of a vector of a difference between a vector in a predetermined range based on the normalized eigenvector and the normalized eigenvector is 2−√2 or less.   6. The power source included in each power transmission device and each power reception device supplies a current or a voltage proportional to a component corresponding to the power source among components of the matrix CX to the antenna. Contactless power supply system.   The contactless power feeding system according to claim 6, wherein a current or voltage proportional to an eigenvector corresponding to a maximum eigenvalue among eigenvalues of the matrix D is supplied to the antenna. Non-contact power supply system according to the square C ² is any one of claims 3 to 7 which is a unit matrix of the matrix C. Non-contact power supply system according to the square C ² is any one of claims 3 to 7 is a real part of the real part or the admittance matrix of the impedance matrix of the matrix C. Non-contact power supply system according to the square C ² is any one of claims 3 to 7 is the inductance matrix of the matrix C. A power transmission system including a plurality of power transmission devices including a first antenna that supplies energy in a non-contact manner by a magnetic field, and a first power source that discharges power by supplying a first amount of electricity to the first antenna; A power receiving system including a plurality of power receiving devices including a second antenna that receives energy in a non-contact manner by a magnetic field, and a second power source that absorbs power by supplying a first amount of electricity to the second antenna A contactless power supply system comprising:
The power transmission system includes:
A first extraction unit that extracts a second electric quantity component in phase with the first electric quantity generated in the first antenna;
A first normalization unit that normalizes a value based on the second electric quantity component extracted by the first extraction unit among the plurality of power transmission devices;
A first power control unit that causes the first power source to generate a second electric quantity after the first normalization unit has standardized;
With
The power receiving system includes a second extraction unit that extracts a second electric quantity component in phase with the first electric quantity generated in the second antenna;
A second normalization unit that normalizes a value based on the second electric quantity component extracted by the second extraction unit among the plurality of power receiving devices;
A second power control unit that causes the second power source to generate a second quantity of electricity after the second normalization unit has standardized;
With
The contactless power feeding system in which the first electric quantity is a voltage and the second electric quantity is a current, or the first electric quantity is a current and the second electric quantity is a voltage. A power transmission system including a plurality of power transmission devices including an antenna that supplies energy in a non-contact manner by a magnetic field, and a power source that discharges power by supplying a first amount of electricity to the antenna,
An extraction unit for extracting a second electric quantity component in phase with the first electric quantity generated in the antenna;
A normalization unit that normalizes a value based on the second electric quantity component extracted by the extraction unit among the plurality of power transmission devices;
A power supply control unit that causes the power supply to generate a second electric quantity after the normalization unit has standardized;
With
The power transmission system wherein the first electric quantity is a voltage and the second electric quantity is a current, or the first electric quantity is a current and the second electric quantity is a voltage. A power receiving system including a plurality of power receiving devices including an antenna that receives energy in a non-contact manner by a magnetic field and a power source that absorbs power by supplying a first amount of electricity to the antenna,
An extraction unit for extracting a second electric quantity component in phase with the first electric quantity generated in the antenna;
A normalization unit that normalizes a value based on the second electric quantity component extracted by the extraction unit among the plurality of power receiving devices;
A power supply control unit that causes the power supply to generate a second electric quantity after the normalization unit has standardized;
With
The power receiving system, wherein the first electric quantity is a voltage and the second electric quantity is a current, or the first electric quantity is a current and the second electric quantity is a voltage. A power transmission method executed by a power transmission system including a plurality of power transmission devices each including an antenna that supplies energy in a non-contact manner by a magnetic field and a power source that discharges power by supplying a first amount of electricity to the antenna,
A procedure for the extraction unit to extract a second electric quantity component in phase with the first electric quantity generated in the antenna;
A procedure for normalizing a value based on the second electric quantity component extracted by the extraction unit between the plurality of power transmission devices;
A procedure for causing the power supply control unit to generate the second electric quantity after the normalization unit normalizes the power supply;
Have
The power transmission method wherein the first electric quantity is a voltage and the second electric quantity is a current, or the first electric quantity is a current and the second electric quantity is a voltage. A power receiving method executed by a power receiving system including a plurality of power receiving devices including an antenna that receives energy in a non-contact manner by a magnetic field and a power source that absorbs power by supplying a first amount of electricity to the antenna,
A procedure for the extraction unit to extract a second electric quantity component in phase with the first electric quantity generated in the antenna;
A procedure for normalizing a value based on the second electric quantity component extracted by the extracting unit between the plurality of power receiving devices;
A procedure for causing the power source to generate a second electric quantity after the power normalization unit has been standardized by the standardization unit;
Have
The power receiving method wherein the first electric quantity is a voltage and the second electric quantity is a current, or the first electric quantity is a current and the second electric quantity is a voltage. On the computer,
An extraction step of extracting a second electric quantity component in phase with the first electric quantity generated in the antenna;
A normalization step of normalizing a value based on the second electrical quantity component extracted in the extraction step between a plurality of power transmission devices or a plurality of power reception devices;
A power supply control step for causing the power supply to generate the second electric quantity after being normalized in the normalization step;
The first electric quantity is a voltage and the second electric quantity is a current, or the first electric quantity is a current and the second electric quantity is a voltage. A program.

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