US 2014/0191819 A1Published application

Impedance matching device and control method

AssigneePioneer Corporation

InventorMasami Suzuki

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Abstract

In an impedance matching device, a storage unit stores a control value representing a load value and a value equivalent to input impedance in advance. The control value identifies inductance and capacitance values matching a predetermined impedance value by use of either a first or second matching circuit. An impedance estimation unit estimates input impedance of the power transmission antenna. The load value estimation unit estimates load value of a circuit connected to a power reception antenna and consuming transmitted electric power. A circuit selection unit electrically connects the first matching circuit, the second matching circuit, or a through circuit per the load value and the input impedance equivalent value. A control value output unit reads out the control value stored in the storage unit based on the load value and the input impedance equivalent value, and outputs the control value to the circuit selected by the circuit selection unit.

Claims20

Dependent claims

An impedance matching device included in a wireless electric power transmission system transmitting electric power by coupling a power transmission antenna with a power reception antenna through an electromagnetic field, the impedance matching device being provided between a power transmission circuit and the power transmission antenna, the impedance matching device comprising:

an input impedance estimation unit configured to estimate an input impedance equivalent value corresponding to input impedance of the power transmission antenna or a value equivalent thereto;
a first matching circuit configured to include a variable inductor element and a variable capacitor element, the variable inductor element being connected in series between the power transmission circuit and the power transmission antenna, the variable capacitor element being connected in parallel closer to the power transmission antenna than the variable inductor element;
a second matching circuit configured to include a variable inductor element and a variable capacitor element, the variable inductor element being connected in series between the power transmission circuit and the power transmission antenna, the variable capacitor element being connected in parallel closer to the power transmission circuit than the variable inductor element;
a through circuit connected in series between the power transmission circuit and the power transmission antenna;
a load value estimation unit configured to estimate a value of a load of a circuit in which the transmitted electric power is consumed, the circuit being connected to the power reception antenna;
a storage unit configured to previously store control values each associated with the value of the load and the input impedance equivalent value, each of the control values corresponding to an inductance value and a capacitance value each needed for matching to a predetermined impedance value by use of the first matching circuit or the second matching circuit;
a circuit selection unit configured to electrically connect one of the first matching circuit, the second matching circuit and the through circuit based on the estimated value of the load and the estimated input impedance equivalent value;
and
a control value output unit configured to read out one of the control values stored in the storage unit based on the estimated value of the load and the estimated input impedance equivalent value, and to output the control value to the circuit selected by the circuit selection unit.

6 more elements

an input impedance estimation unit configured to estimate an input impedance equivalent value corresponding to input impedance of the power transmission antenna or a value equivalent thereto;
a first matching circuit configured to include a variable inductor element and a variable capacitor element, the variable inductor element being connected in series between the power transmission circuit and the power transmission antenna, the variable capacitor element being connected in parallel closer to the power transmission antenna than the variable inductor element;
a second matching circuit configured to include a variable inductor element and a variable capacitor element, the variable inductor element being connected in series between the power transmission circuit and the power transmission antenna, the variable capacitor element being connected in parallel closer to the power transmission circuit than the variable inductor element;
a through circuit connected in series between the power transmission circuit and the power transmission antenna;
a coupling coefficient estimation unit configured to estimate a coupling coefficient between the power transmission antenna and the power reception antenna;
a storage unit configured to previously store control values each associated with the coupling coefficient and the input impedance equivalent value, each of the control values corresponding to an inductance value and a capacitance value each needed for matching to a predetermined impedance value by use of the first matching circuit or the second matching circuit;
a circuit selection unit configured to electrically connect one of the first matching circuit, the second matching circuit and the through circuit based on the estimated coupling coefficient and the estimated input impedance equivalent value;
and
a control value output unit configured to read out one of the control values stored in the storage unit based on the estimated coupling coefficient and the estimated input impedance equivalent value, and to output the control value to the circuit selected by the circuit selection unit.

6 more elements

A control method executed by an impedance matching device included in a wireless electric power transmission system transmitting electric power by coupling a power transmission antenna with a power reception antenna through an electromagnetic field, the impedance matching device being provided between a power transmission circuit and the power transmission antenna, the impedance matching device comprising:

a first matching circuit configured to include a variable inductor element and a variable capacitor element, the variable inductor element being connected in series between the power transmission circuit and the power transmission antenna, the variable capacitor element being connected in parallel closer to the power transmission antenna than the variable inductor element;
a second matching circuit configured to include a variable inductor element and a variable capacitor element, the variable inductor element being connected in series between the power transmission circuit and the power transmission antenna, the variable capacitor element being connected in parallel closer to the power transmission circuit than the variable inductor element;
a through circuit connected in series between the power transmission circuit and the power transmission antenna;
and
a storage unit configured to previously store control values each associated with a value of a load of a circuit in which the transmitted electric power is consumed and an input impedance equivalent value, each of the control values corresponding to an inductance value and a capacitance value each needed for matching to a predetermined impedance value by use of the first matching circuit or the second matching circuit, the input impedance equivalent value corresponding to input impedance of the power transmission antenna or a value equivalent thereto, the circuit being connected to the power reception antenna,
the control method comprising:
an input impedance estimation process for estimating the input impedance equivalent value;
a load value estimation process for estimating the value of the load;
a circuit selection process for electrically connecting one of the first matching circuit, the second matching circuit and the through circuit based on the estimated value of the load and the estimated input impedance equivalent value;
and
a control value output process for reading out one of the control values stored in the storage unit based on the estimated value of the load and the estimated input impedance equivalent value, and for outputting the control value to the circuit selected in the circuit selection process.

8 more elements

a first matching circuit configured to include a variable inductor element and a variable capacitor element, the variable inductor element being connected in series between the power transmission circuit and the power transmission antenna, the variable capacitor element being connected in parallel closer to the power transmission antenna than the variable inductor element;
a second matching circuit configured to include a variable inductor element and a variable capacitor element, the variable inductor element being connected in series between the power transmission circuit and the power transmission antenna, the variable capacitor element being connected in parallel closer to the power transmission circuit than the variable inductor element;
a through circuit connected in series between the power transmission circuit and the power transmission antenna;
and
a storage unit configured to previously store control values each associated with a coupling coefficient between the power transmission antenna and the power reception antenna and an input impedance equivalent value, each of the control values corresponding to an inductance value and a capacitance value each needed for matching to a predetermined impedance value by use of the first matching circuit or the second matching circuit, the input impedance equivalent value corresponding to input impedance of the power transmission antenna or a value equivalent thereto,
the control method comprising:
an input impedance estimation process for estimating the input impedance equivalent value;
a coupling state estimation process for estimating the coupling coefficient;
a circuit selection process for electrically connecting one of the first matching circuit, the second matching circuit and the through circuit based on the estimated coupling coefficient and the estimated input impedance equivalent value;
and
a control value output process for reading out one of the control values stored in the storage unit based on the estimated coupling coefficient and the estimated input impedance equivalent value, and for outputting the control value to the circuit selected in the circuit selection process.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/124,359Filed 7 Jun 2011
Published: 10 Jul 2014
Term ends: Not estimatedThe source records don’t support an estimate.

Classification11 codes

H03H 7/40
Impedance-matching networks: automatic matching of load impedance to source impedance
H01F 38/14
Adaptations of transformers or inductances for specific applications or functions: inductive couplings
H02J 50/10
Circuit arrangements or systems for wireless supply or distribution of electric power: using inductive coupling
H02J 50/12
Using inductive coupling: of the resonant type

Family

US 9,331,663 B2Related patent
US 2014/0191819 A1This patent

From the US filing history. Foreign family members aren’t listed.

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