APPARATUSES, SYSTEMS, AND METHODS FOR POWER TRANSFER ADJUSTMENT IN WIRELESS POWER TRANSFER SYSTEMS

• US 20130257167A1
• Filed: 03/29/2012
• Published: 10/03/2013
• Est. Priority Date: 03/29/2012
• Status: Abandoned Application

• Current Assignee: Integrated Device Technology Incorporated (Renesas Electronics Corporation)
• Original Assignee: Integrated Device Technology Incorporated (Renesas Electronics Corporation)
• Inventors: Singh, Manjit
• Application Number:
  US13/434,641
• Publication Number:
  US 20130257167A1
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries

Abstract

A wireless power-transfer system includes a power-transmitting device and a power-receiving device. The power-transmitting device includes, a frequency generator for generating a power-transmit frequency and a transmit coil for generating a near-field electromagnetic radiation responsive to the power-transmit frequency. The power-receiving device, includes a receive resonance circuit that generates a receive resonance frequency and includes a receive coil for receiving the near-field electromagnetic radiation when within a coupling region of the transmit coil and a receive capacitor in combination with the receive coil. The rectifier converts the receive resonance signal to a rectified signal. The signal sensor senses at least one of a voltage or a current on the rectified signal to generate a power indicator signal. The receive impedance adjuster modifies a resonant frequency of the receive resonance circuit responsive to the power indicator signal by selectively modifying an impedance of the receive impedance adjuster.

Claims

1. A power-receiving device, comprising:

a receive resonance circuit configured to generate a receive resonance frequency, comprising;

a receive coil for receiving near-field electromagnetic radiation at a coupling frequency when within a coupling region of a transmit coil; and

a receive capacitor operably coupled to the receive coil and configured to operate in combination with the receive coil to generate a receive resonance signal at the receive resonance frequency when the receive coil is stimulated by the near-field electromagnetic radiation;

a rectifier operably coupled to the receive resonance signal and configured to convert the receive resonance signal to a rectified signal at a substantially Direct Current (DC) level;

a signal sensor operably coupled to the rectified signal and configured to sense at least one of a voltage or a current on the rectified signal to generate a power indicator signal; and

a receive impedance adjuster operably and selectively coupled to the receive resonance circuit and configured to adjust a resonant frequency of the receive resonance circuit responsive to the power indicator signal by selectively modifying an impedance of the receive impedance adjuster.

2. The power-receiving device of claim 1, wherein the receive impedance adjuster comprises a variable capacitance and the variable capacitance is configured to be selectively adjusted responsive to the power indicator signal.

3. The power-receiving device of claim 1, wherein the receive impedance adjuster comprises a variable inductance and the variable inductance is configured to be selectively adjusted responsive to the power indicator signal.

4. The power-receiving device of claim 1, wherein the receive impedance adjuster comprises:

a variable capacitance; and

a variable inductance;

wherein the resonant frequency is configured to be selectively adjusted by adjusting at least one of the variable capacitance and the variable inductance.

5. The power-receiving device of claim 1, wherein the receive impedance adjuster comprises a network comprising first components to generate at least a capacitive portion of the receive impedance adjuster.

6. The power-receiving device of claim 5, wherein the first components comprise at least one first active component configured as a switch operably coupled to include at least one corresponding capacitor.

7. The power-receiving device of claim 5, wherein the network further comprises second components including at least one second active component configured as a switch operably coupled to include at least one corresponding inductor.

8. The power-receiving device of claim 1, further comprising a receive controller configured to control the power indicator signal responsive to an analysis of at least one of a sampled voltage on the rectified signal and a sampled current on the rectified signal.

9. A method of receiving power, comprising:

stimulating a receive resonance circuit including a receive coil and a receive capacitor to generate a receive resonance signal at a receive resonance frequency by positioning the receive coil in a coupling region of a transmit coil generating a near-field electromagnetic radiation at a coupling frequency;

rectifying the receive resonance signal to a rectified signal at substantially a DC level;

sensing at least one of a voltage or a current on the rectified signal to generate a power indicator signal; and

adjusting a resonant frequency of the receive resonance circuit responsive to the power indicator signal by selectively modifying an impedance of a receive impedance adjuster operably coupled to the receive resonance circuit.

10. The method of claim 9, further comprising adjusting at least a capacitive portion of the receive impedance adjuster to adjust the receive resonance frequency.

11. The method of claim 10, wherein adjusting at least the capacitive portion comprises selectively and operably coupling one or more capacitors to the receive resonance circuit.

12. The method of claim 9, further comprising adjusting at least an inductive portion of the receive impedance adjuster to adjust the receive resonance frequency.

13. The method of claim 12, wherein adjusting at least the inductive portion comprises selectively and operably coupling one or more inductors to the receive resonance circuit.

14. The method of claim 9, further comprising:

sampling at least one of a voltage and a current on the rectified signal; and

performing an analysis to determine the power indicator signal responsive to the sampled voltage, the sampled current, or a combination thereof.

15. A wireless power-transfer system, comprising:

a power-transmitting device, comprising;

a frequency generator for generating a power-transmit frequency; and

a transmit coil for generating a near-field electromagnetic radiation at a transmit resonance frequency responsive to the power-transmit frequency; and

a power-receiving device, comprising;

a receive resonance circuit configured to generate a receive resonance frequency, comprising;

a receive coil for receiving the near-field electromagnetic radiation at a coupling frequency when within a coupling region of the transmit coil; and

a receive capacitor operably coupled to the receive coil and configured to operate in combination with the receive coil to generate a receive resonance signal at the receive resonance frequency when the receive coil is stimulated by the near-field electromagnetic radiation;

a rectifier operably coupled to the receive resonance signal and configured to convert the receive resonance signal to a rectified signal at substantially a DC level;

a signal sensor operably coupled to the rectified signal and configured to sense at least one of a voltage or a current on the rectified signal to generate a power indicator signal; and

a receive impedance adjuster operably and selectively coupled to the receive resonance circuit and configured to adjust a resonant frequency of the receive resonance circuit responsive to the power indicator signal by selectively modifying an impedance of the receive impedance adjuster.

16. The wireless power-transfer system of claim 15, wherein the receive impedance adjuster comprises a variable capacitance and the variable capacitance is configured to be selectively adjusted responsive to the power indicator signal.

17. The wireless power-transfer system of claim 15, wherein the receive impedance adjuster comprises a variable inductance and the variable inductance is configured to be selectively adjusted responsive to the power indicator signal.

18. The wireless power-transfer system of claim 15, wherein the receive impedance adjuster comprises:

a variable capacitance; and

a variable inductance;

wherein the resonant frequency is configured to be selectively adjusted by adjusting at least one of the variable capacitance and the variable inductance.

19. The wireless power-transfer system of claim 15, wherein the receive impedance adjuster comprises a network comprising first components to generate at least a capacitive portion of the receive impedance adjuster.

20. The wireless power-transfer system of claim 19, wherein the first components comprise at least one first active component configured as a switch operably coupled to include at least one corresponding capacitor.

21. The wireless power-transfer system of claim 19, wherein the network further comprises second components including at least one second active component configured as a switch operably coupled to include at least one corresponding inductor.

22. The wireless power-transfer system of claim 15, further comprising a receive controller configured to control the power indicator signal responsive to an analysis of at least one of a sampled voltage on the rectified signal and a sampled current on the rectified signal.