Contactless power transfer system, contactless power transfer device, contactless power transfer program and contactless power transfer method

• US 9,640,316 B2
• Filed: 06/07/2012
• Issued: 05/02/2017
• Est. Priority Date: 06/07/2011
• Status: Active Grant

• Current Assignee: Sekisui Chemical Company Limited (Sekisui)
• Original Assignee: Sekisui Chemical Company Limited (Sekisui)
• Inventors: Iwasa, Koichiro, Nakamura, Masanori, Ishi, Tetsuya, Shokaku, Akio
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Warmflash, Michael
• Application Number:
  US14/123,867
• Publication Number:
  US 20140175895A1
• Time in Patent Office: 1,790 Days
• Field of Search: 307104
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 7/00304 Overcurrent protection

Abstract

A parent device power transmission unit determines a power to be supplied to a plurality of coils such that the power is proportional to an eigenvector of a real part of an impedance matrix which is based on a mutual inductance of the plurality of coils.

Claims

1. A contactless power transfer system comprising:

N parent device power transmission units (N is an integer equal to or more than

     2);

at least one child device power reception unit; and

a distribution determination unit configured to determine an electrical signal to be supplied to the N parent device power transmission units, wherein

the electrical signal has a current, a voltage or a linear combination amount of the current and the voltage as a component,

in case that an N-dimensional vector having the electrical signal to be supplied to each parent device power transmission unit as a component is X, the distribution determination unit is configured to set a matrix A as a regularized Hermitian matrix of N rows×

N columns, and

{tilde over (X)}*AX 

 

(1)

in case that a scalar of Equation (1) (˜

denotes a transposed matrix and * denotes a complex conjugate) is non-negative, a quadratic form matrix of the electrical signal in case that the child device power reception unit functions is a matrix B which expresses dissipation of energy and which is Hermite of N rows×

N columns having a coefficient thereof as a component, a scalar of Equation (2) expresses energy consumption,

{tilde over (X)}*BX 

 

(2)

and the matrix A is expressed as shown in Equation (3),

A={tilde over (C)}*C 

 

(3)

the distribution determination unit is configured to determine the electrical signal to be proportional to a component of a vector C<sup>−

1</sup>Y obtained by multiplying a linear combination of an eigenvector Y for a non-zero eigenvalue of a matrix D expressed by Equation (4) by the matrix C<sup>−

1</sup> from the left

D={tilde over (C)}*<sup>−

1</sup>BC<sup>−

1</sup> 

 

(4).

2. The contactless power transfer system according to claim 1, wherein

the matrix B is a matrix of a real part of an impedance matrix or a real part of an admittance matrix for a terminal of each parent device power transmission unit in case that the child device power reception unit functions, and

the distribution determination unit is configured to determine the electrical signal to be supplied to the N parent device power transmission units based on a reference matrix which is a Hermitian matrix with definite positive values indicating a quadratic form of the electrical signal and the matrix B.

3. The contactless power transfer system according to claim 2, wherein

the distribution determination unit is configured to determine the electrical signal to be supplied to the N parent device power transmission units to be proportional to a component of the vector C⁻

1Y calculated based on the eigenvector Y for a maximum eigenvalue of the matrix D or to be proportional to the component of the vector C<sup>−

1</sup>Y calculated based on the eigenvector Y for a minimum eigenvalue of the matrix D.

4. The contactless power transfer system according to claim 1, wherein

the matrix A is a unit matrix.

5. The contactless power transfer system according to claim 1, wherein

the matrix A is a real part of the impedance matrix or a real part of the admittance matrix in case that there is no child device power reception unit.

6. The contactless power transfer system according to claim 1, wherein

the matrix A is one of an imaginary part of the impedance matrix, a real part of the capacitance matrix, and a real part of the inductance matrix of each parent device power transmission unit.

7. The contactless power transfer system according to claim 1, wherein

the scalar of Equation (1) of the quadratic form is a sum of energies of a field accumulated in a space of a specific area.

8. The contactless power transfer system according to claim 1, wherein

the distribution determination unit is configured to determine the electrical signal to be supplied to the N parent device power transmission units so that a current corresponding to a component having a maximum absolute value among components of the eigenvector is a current rating or so that a voltage corresponding to a component having a maximum absolute value among components of the eigenvector is a voltage rating.

9. The contactless power transfer system according to claim 2, wherein

the reference matrix is a real part of the impedance matrix or a real part of the admittance matrix in case that there is no child device power reception unit or a real part of the inductance matrix between the N parent device power transmission units, or an imaginary part of the impedance matrix between the parent device power transmission units or an imaginary part of the admittance matrix between the parent device power transmission units is a Hermitian coefficient matrix in case that energy induced to a specific area in a space is expressed in a quadratic form of the electrical signal.

10. The contactless power transfer system according to claim 1, wherein

the vector Y in the distribution determination unit determines the electrical signal to be supplied to the N parent device power transmission units to converge on the eigenvector of the matrix D.

11. The contactless power transfer system according to claim 1, wherein

the child device power reception unit has a power reception refusal mode to limit power transfer from the N parent device power transmission units.

12. The contactless power transfer system according to claim 1, wherein

the contactless power transfer system comprises a control unit configured to limit the supplied electrical signal and output a resultant electrical signal to the parent device power transmission unit.

13. The contactless power transfer system according to claim 12, wherein

the control unit is configured to limit the electrical signal using an element whose energy dissipation is negligible in comparison with the energy of the electrical signal.

14. The contactless power transfer system according to claim 1, wherein

the parent device power transmission unit comprises a power transmission unit,

the child device power reception unit comprises a power reception unit,

each of the power transmission unit and the power reception unit comprises an inductor, and

magnetic field coupling is made by resonance based on the inductor of the power transmission unit and the inductor of the power reception unit.

15. The contactless power transfer system according to claim 1, wherein

the parent device power transmission unit comprises a power transmission unit,

the child device power reception unit comprises a power reception unit,

each of the power transmission unit and the power reception unit comprises a capacitor, and

capacitive coupling is made by resonance based on the capacitor of the power transmission unit and the capacitor of the power reception unit.

16. The contactless power transfer system according to claim 12, wherein

the control unit comprises a plurality of capacitors and a plurality of switching units,

the plurality of capacitors comprises one terminals connected to one another, and other terminals connected to input terminals of the respective switching units,

output terminals of the plurality of switching units are connected to one another, and a connection point thereof is connected to a coil, and

the distribution determination unit is configured to determine distribution of the electrical signal to be supplied to the N parent device power transmission units, based on information indicating a voltage applied to the coil in case that the switching units are sequentially switched and information indicating a current flowing through the capacitor.

17. The contactless power transfer system according to claim 12, wherein

the control unit comprises:

a plurality of capacitors; and

a plurality of switching units each comprising first to third ports and comprising a port switching switch configured to switch a connection between the first or second port with the third port among first to third ports,

in the plurality of switching units, the first ports are connected to one another, a first connection point thereof is connected to a power supply unit, the second ports are connected to one another, each second port is grounded, and the third port is connected to one terminal of one of the plurality of capacitors,

in the plurality of capacitors, the other terminals are connected to one another, and a second connection point thereof is connected to a coil, and

the switching unit is configured to determine distribution of the electrical signal to be supplied to the N parent device power transmission units based on information indicating a current flowing through the second connection point in case that the switching units are sequentially switched and information indicating a voltage applied to a coil.

18. The contactless power transfer system according to claim 1, wherein

the electrical signal is supplied from a smaller number of power supplies than the number of parent device power transmission units.

19. A contactless power transfer system comprising:

N parent device power transmission units (N is an integer equal to or more than

     2);

at least one child device power reception unit; and

a distribution determination unit configured to determine an electrical signal to be supplied to the N parent device power transmission units, wherein

the electrical signal has a current, a voltage or a linear combination amount of the current and the voltage as a component, and

the distribution determination unit is configured to determine the electrical signal to be supplied to the N parent device power transmission units to be proportional to a component of an eigenvalue vector for a non-zero eigenvalue of a matrix B of a real part of an impedance matrix or a real part of an admittance matrix in case that there is a child device power reception unit.

20. A contactless power transfer device comprising:

N parent device power transmission units (N is an integer equal to or more than

     2);

at least one child device power reception unit; and

a distribution determination unit configured to determine an electrical signal to be supplied to the N parent device power transmission units, wherein

the electrical signal has a current, a voltage or a linear combination amount of the current and the voltage as a component,

in case that an N-dimensional vector of N rows×

1 column having the electrical signal to be supplied to each parent device power transmission unit as a component is X, the distribution determination unit is configured to set a matrix A as a regularized Hermitian matrix of N rows×

N columns, and

{tilde over (X)}*AX 

 

(5)

in case that a scalar of Equation (5) (˜

denotes a transposed matrix and * denotes a complex conjugate) is non-negative, a quadratic form matrix of the electrical signal in case that the child device power reception unit functions is a matrix B which expresses dissipation of energy and which is Hermite of N rows×

N columns having a coefficient thereof as a component, a scalar of Equation (6) expresses energy consumption,

{tilde over (X)}*BX 

 

(6)

and the matrix A is expressed as shown in Equation (7),

A={tilde over (C)}*C 

 

(7)

the distribution determination unit is configured to determine the electrical signal to be proportional to a component of a vector C<sup>−

1</sup>Y obtained by multiplying a linear combination of an eigenvector Y for a non-zero eigenvalue of a matrix D expressed by Equation (8) by the matrix C<sup>−

1</sup> from the left

D={tilde over (C)}*<sup>−

1</sup>BC<sup>−

1</sup> 

 

(8).

21. A contactless power transfer device comprising:

N parent device power transmission units (N is an integer equal to or more than

     2);

at least one child device power reception unit; and

a distribution determination unit which configured to determine an electrical signal to be supplied to the N parent device power transmission units, wherein

the electrical signal has a current, a voltage or a linear combination amount of the current and the voltage as a component, and

the distribution determination unit is configured to determine the electrical signal to be supplied to the N parent device power transmission units to be proportional to a component of an eigenvalue vector for a non-zero eigenvalue of a matrix B of a real part of an impedance matrix or a real part of an admittance matrix in case that there is a child device power reception unit.

22. A non-transitory computer-readable recording medium storing a contactless power transfer program for causing a computer of a contactless power transfer device of a contactless power transfer system in which an electrical signal has a current, a voltage or a linear combination amount of the current and the voltage as a component and which comprises N parent device power transmission units (N is an integer equal to or more than 2), at least one child device power reception unit, and a distribution determination unit which determines the electrical signal to be supplied to the N parent device power transmission units to execute a procedure in which:

in case that an N-dimensional vector of N rows×

1 column having the electrical signal to be supplied to each parent device power transmission unit as a component is X, the distribution determination unit sets a matrix A as a regularized Hermitian matrix of N rows×

N columns, and

{tilde over (X)}*AX 

 

(9)

in case that a scalar of Equation (9) (˜

denotes a transposed matrix and * denotes a complex conjugate) is non-negative, a quadratic form matrix of the electrical signal in case that the child device power reception unit functions is a matrix B which expresses dissipation of energy and which is Hermite of N rows×

N columns having a coefficient thereof as a component, a scalar of Equation (10) expresses energy consumption,

{tilde over (X)}*BX 

 

(10)

and the matrix A is expressed as shown in Equation (11),

A={tilde over (C)}*C 

 

(11)

the distribution determination unit determines the electrical signal to be proportional to a component of a vector C<sup>−

1</sup>Y obtained by multiplying a linear combination of an eigenvector Y for a non-zero eigenvalue of a matrix D expressed by Equation (12) by the matrix C<sup>−

1</sup> from the left

D={tilde over (C)}*<sup>−

1</sup>BC<sup>−

1</sup> 

 

(12).

23. A non-transitory computer-readable recording medium storing a contactless power transfer program for causing a computer of a contactless power transfer device of a contactless power transfer system in which an electrical signal has a current, a voltage or a linear combination amount of the current and the voltage as a component, and which comprises N parent device power transmission units (N is an integer equal to or more than 2), at least one child device power reception unit, and a distribution determination unit which determines an electrical signal to be supplied to the N parent device power transmission units to execute a procedure in which:

the distribution determination unit determines the electrical signal to be supplied to the N parent device power transmission units to be proportional to a component of an eigenvalue vector for a non-zero eigenvalue of a matrix B of a real part of an impedance matrix or a real part of an admittance matrix in case that there is a child device power reception unit.

24. A contactless power transfer method in a contactless power transfer device of a contactless power transfer system in which an electrical signal has a current, a voltage or a linear combination amount of the current and the voltage as a component and which comprises N parent device power transmission units (N is an integer equal to or more than 2), at least one child device power reception unit, and a distribution determination unit which determines an electrical signal to be supplied to the N parent device power transmission units, the contactless power transfer method comprising:

a procedure in which, in case that an N-dimensional vector of N rows×

1 column having the electrical signal to be supplied to each parent device power transmission unit as a component is X, the distribution determination unit sets a matrix A as a regularized Hermitian matrix of N rows×

N columns, and

{tilde over (X)}*AX 

 

(13)

in case that a scalar of Equation (13) (˜

denotes a transposed matrix and * denotes a complex conjugate) is non-negative, a quadratic form matrix of the electrical signal in case that the child device power reception unit functions is a matrix B which expresses dissipation of energy and which is Hermite of N rows×

N columns having a coefficient thereof as a component, a scalar of Equation (14) expresses energy consumption,

{tilde over (X)}*BX 

 

(14)

and the matrix A is expressed as shown in Equation (15),

A={tilde over (C)}*C 

 

(15)

the distribution determination unit determines the electrical signal to be proportional to a component of a vector C<sup>−

1</sup>Y obtained by multiplying a linear combination of an eigenvector Y for a non-zero eigenvalue of a matrix D expressed by Equation (16) by the matrix C<sup>−

1</sup> from the left.

D={tilde over (C)}*<sup>−

1</sup>BC<sup>−

1</sup> 

 

(16).

25. A contactless power transfer method in a contactless power transfer device of a contactless power transfer system in which an electrical signal has a current, a voltage or a linear combination amount of the current and the voltage as a component and which comprises N parent device power transmission units (N is an integer equal to or more than 2), at least one child device power reception unit, and a distribution determination unit which determines the electrical signal to be supplied to the N parent device power transmission units, the contactless power transfer method comprising:

a procedure in which the distribution determination unit determines the electrical signal to be supplied to the N parent device power transmission units to be proportional to a component of an eigenvalue vector for a non-zero eigenvalue of a matrix B of a real part of an impedance matrix or a real part of an admittance matrix in case that there is a child device power reception unit.