SENSING DEVICE, POWER RECEPTION DEVICE, POWER TRANSMISSION DEVICE, NON-CONTACT POWER TRANSMISSION SYSTEM, AND SENSING METHOD

• US 20130063160A1
• Filed: 08/31/2012
• Published: 03/14/2013
• Est. Priority Date: 09/09/2011
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Nakano, Hiroaki, Kozakai, Osamu, Fujimaki, Kenichi, Murakami, Tomomichi
• Granted Patent: US 9,057,753 B2
• Time in Patent Office: Days
• US Class Current: 324/653
• CPC Class Codes: G01R 27/28 Measuring attenuation, gain, phase shift or derived characteristics of electric four pole networks, i.e. two-port networks; Measuring transient response in line transmission systems H04B3/46
• CPC Class Codes: G01R 31/346 Testing of armature or field windings
• CPC Class Codes: G01R 31/42 AC power supplies
• CPC Class Codes: G01R 31/72 Testing of electric windings testing of transformers G01R31/62
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings

Abstract

There is provided a sensing device including a circuit including at least a coil electromagnetically coupled to an outside; a temperature detection unit for detecting a temperature of the coil; a sensing unit for measuring a Q value of the circuit; and a correction unit for correcting the Q value measured by the sensing unit based on temperature information detected by the temperature detection unit.

Claims

1. A sensing device comprising:

a circuit including at least a coil electromagnetically coupled to an outside;

a temperature detection unit for detecting a temperature of the coil;

a sensing unit for measuring a Q value of the circuit; and

a correction unit for correcting the Q value measured by the sensing unit based on temperature information detected by the temperature detection unit.

2. The sensing device according to claim 1, further comprising:

a determination unit for comparing the corrected Q value to a threshold value and determining that there is a metallic foreign material between the coil and the outside when the corrected Q value exceeds the threshold value.

3. The sensing device according to claim 2,

wherein the correction unit corrects the threshold value based on the temperature information, and

wherein the determination unit determines that there is a metallic foreign material between the coil and the outside when the corrected Q value exceeds the corrected threshold value.

4. The sensing device according to claim 1, wherein the corrected Q value is obtained as follows:

Corrected Q Value=(Q Value at Steady Temperature)×

{1−

(Measured Temperature−

Steady Temperature)×

(Metal Temperature Coefficient)}.

5. The sensing device according to claim 3, wherein the corrected threshold value is obtained as follows:

Corrected Threshold Value=(Threshold Value at Steady Temperature)×

{1−

(Measured Temperature−

Steady Temperature)×

(Metal Temperature Coefficient)}.

6. The sensing device according to claim 1, wherein efficiency between the coils after the correction is obtained using the corrected Q value as follows:

Corrected Efficiency between Coils=(Corrected Primary-Side Q Value×

Corrected Secondary-Side Q Value×

k)²/{1+√

(1+Corrected Primary-Side Q Value×

Corrected Secondary-Side Q Value×

k)}², where k denotes a coupling coefficient.

7. The sensing device according to claim 6, wherein, when the coupling coefficient is small, the efficiency between the coils after the correction is approximated as follows:

Corrected Efficiency between Coils=Value of Efficiency between Coils at Steady Temperature−

{0.2×

((Temperature Measured at Primary Side×

Temperature Measured at Secondary Side)−

Steady Temperature}.

8. The sensing device according to claim 2, comprising:

a memory for storing the threshold value,

wherein the determination unit reads the threshold value stored in the memory, and compares the read threshold value to the corrected Q value.

9. The sensing device according to claim 1, further comprising:

a control unit for stopping electromagnetic coupling between the coil and the outside when the temperature of the coil detected by the temperature detection unit exceeds a predetermined value.

10. The sensing device according to claim 1,

wherein the temperature detection unit is configured using a thermistor, and

wherein the sensing unit acquires a voltage value corresponding to the temperature of the coil from the temperature detection unit and detects the temperature of the coil using the voltage value.

11. A power reception device comprising:

a coil to be used for power reception from an outside;

a circuit including at least the coil;

a temperature detection unit for detecting a temperature of the coil;

a sensing unit for measuring a Q value of the circuit; and

a correction unit for correcting the Q value measured by the sensing unit based on temperature information detected by the temperature detection unit.

12. A power transmission device comprising:

a coil to be used for power transmission to an outside;

a circuit including at least the coil;

a temperature detection unit for detecting a temperature of the coil;

a sensing unit for measuring a Q value of the circuit; and

a correction unit for correcting the Q value measured by the sensing unit based on temperature information detected by the temperature detection unit.

13. A non-contact power transmission system comprising:

a power transmission device for wirelessly transmitting power; and

a power reception device for receiving the power from the power transmission device,

wherein at least one of the power transmission device and the power reception device includes

a coil electromagnetically coupled to an outside,

a circuit including at least the coil,

a temperature detection unit for detecting a temperature of the coil,

a sensing unit for measuring a Q value of the circuit, and

a correction unit for correcting the Q value measured by the sensing unit based on temperature information detected by the temperature detection unit.

14. A sensing method comprising:

detecting, with a temperature detection unit, a temperature of a coil to be used for power transmission or power reception;

measuring, with a sensing unit, a Q value of a circuit including the coil; and

correcting the Q value measured by the sensing unit based on temperature information detected by the temperature detection unit.