Wireless energy transfer device

• US 8,664,802 B2
• Filed: 04/14/2009
• Issued: 03/04/2014
• Est. Priority Date: 04/15/2008
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Fukada, Yoshiki
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Pham, Duc M
• Application Number:
  US12/933,264
• Publication Number:
  US 20110121658A1
• Time in Patent Office: 1,785 Days
• Field of Search: 307/104
• US Class Current: 307/104
• 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
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices

Abstract

A wireless energy transfer device (1) includes: a power transmission unit (2) that generates an oscillating magnetic field or oscillating electric field; a power reception unit (3), which is provided with a receiving antenna (31), and which converts the oscillating magnetic field or the oscillating electric field of the power transmission unit (2) to electric power by the receiving antenna (31); and an electric power theft suppression unit that suppresses the theft of energy with the oscillating magnetic field or the oscillating electric field of the power transmission unit (2).

Claims

1. A wireless energy transfer device, comprising:

a power transmission unit that generates an oscillating magnetic field or an oscillating electric field;

a power reception unit, which is provided with a receiving antenna, and which converts the oscillating magnetic field or the oscillating electric field of the power transmission unit to electric power with the receiving antenna; and

an electric power theft suppression unit that suppresses a theft of energy with the oscillating magnetic field or the oscillating electric field generated by the power transmission unit, wherein

the electric power theft suppression unit comprises;

a frequency changing unit that changes a frequency of the oscillating magnetic field or the oscillating electric field generated by the power transmission unit,

a first resonance frequency changing unit that changes a resonance frequency of the receiving antenna according to the change in the frequency of the oscillating magnetic field or the oscillating electric field,

a detection unit that detects a second oscillating magnetic field or a second oscillating electric field formed in a vicinity of the power transmission unit, and

an electric power theft determination unit that determines whether the electric power is stolen based on a status of the second oscillating magnetic field or a status of the second oscillating electric field detected by the detection unit during transmission of the electric power from the power transmission unit to the power reception unit.

2. The wireless energy transfer device according to claim 1, further comprising a communication unit that transmits information on the frequency of the oscillating magnetic field or the oscillating electric field generated by the power transmission unit to the first resonance frequency changing unit.

3. The wireless energy transfer device according to claim 2, wherein the communication unit transmits, to the first resonance frequency changing unit, the information on the frequency of the oscillating magnetic field or the oscillating electric field generated by the power transmission unit after encrypting the information.

4. The wireless energy transfer device according to claim 1, wherein the frequency changing unit makes a rate of increase in the frequency larger than a rate of decrease in the frequency when changing the frequency of the oscillating magnetic field or the oscillating electric field.

5. The wireless energy transfer device according to claim 1, wherein the power transmission unit comprises:

a power transmission antenna that generates the oscillating magnetic field or the oscillating electric field; and

a second resonance frequency changing unit that changes a resonance frequency of the power transmission antenna according to a change in the frequency of the oscillating magnetic field or the oscillating electric field.

6. The wireless energy transfer device according to claim 1, further comprising an output changing unit that changes an amplitude of the oscillating magnetic field or the oscillating electric field emitted by the power transmission unit.

7. The wireless energy transfer device according to claim 1, further comprising a notification unit that issues a notification when a theft of electric power is determined by the electric power theft determination unit.

8. The wireless energy transfer device according to claim 1, further comprising an interruption unit that interrupts electric power transfer when theft of electric power is determined by the electric power theft determination unit.

9. The wireless energy transfer device according to claim 8, wherein the interruption unit interrupts generation of the oscillating magnetic field or the oscillating electric field in the power transmission unit.