RESONANT TYPE TRANSMISSION POWER SUPPLY DEVICE AND RESONANT TYPE TRANSMISSION POWER SUPPLY SYSTEM

• US 20170005524A1
• Filed: 12/26/2013
• Published: 01/05/2017
• Est. Priority Date: 12/26/2013
• Status: Abandoned Application

• Current Assignee: Mitsubshi Electric Engineering Company Limited (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubshi Electric Engineering Company Limited (Mitsubishi Electric Corporation)
• Inventors: AKUZAWA, Yoshiyuki, SAKAI, Kiyohide, EZOE, Toshihiro, ITO, Yuki
• Application Number:
  US15/107,330
• Publication Number:
  US 20170005524A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02J 50/05 using capacitive coupling
• 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 50/60 responsive to the presence of foreign objects, e.g. detection of living beings

Abstract

A resonant type transmission power supply device includes a pulse input circuit that inputs a pulse voltage to a transmission antenna at set intervals, a variable resonance frequency circuit that causes the resonance frequency of the transmission antenna to be variable and performs sweep detection of the resonance frequency when a pulse voltage is inputted, a frequency characteristic detecting circuit that detects a frequency characteristic of the transmission antenna when the sweep detection is performed, a foreign object detecting circuit that detects the presence or absence of a foreign object in an electromagnetic field generated from the transmission antenna on the basis of a detection result acquired by the frequency characteristic detecting circuit, and a power control circuit that reduces or stops the supply of electric power to the transmission antenna when a foreign object is detected.

Claims

1. A resonant type transmission power supply device comprising:

a pulse input circuit to input a pulse voltage to a transmission antenna at set intervals;

a variable resonance frequency circuit to cause a resonance frequency of said transmission antenna to be variable and perform sweep detection of the resonance frequency when a pulse voltage is inputted by said pulse input circuit;

a frequency characteristic detecting circuit to detect a frequency characteristic of said transmission antenna when the sweep detection of the resonance frequency is performed by said variable resonance frequency circuit;

a foreign object detecting circuit to detect presence or absence of a foreign object in an electromagnetic field generated from said transmission antenna on a basis of a detection result acquired by said frequency characteristic detecting circuit; and

a power control circuit to reduce or stop supply of electric power to said transmission antenna when a foreign object is detected by said foreign object detecting circuit.

2. The resonant type transmission power supply device according to claim 1, wherein said frequency characteristic detecting circuit detects, as the frequency characteristic, at least one of a frequency of reflection power from said transmission antenna, a frequency of a voltage inputted to said transmission antenna, and a frequency of a current inputted to said transmission antenna.

3. The resonant type transmission power supply device according to claim 2, wherein said frequency characteristic detecting circuit detects at least one of a phase difference between said voltage and said current, and amplitudes of said reflection power, said voltage and said current.

4. The resonant type transmission power supply device according to claim 1, wherein said transmission antenna performs wireless power transmission according to magnetic-field resonance with a reception antenna, and said variable resonance frequency circuit matches a resonance condition of said transmission antenna to that of said reception antenna.

5. The resonant type transmission power supply device according to claim 1, wherein said transmission antenna performs wireless power transmission according to electric-field resonance with a reception antenna, and said variable resonance frequency circuit matches a resonance condition of said transmission antenna to that of said reception antenna.

6. The resonant type transmission power supply device according to claim 1, wherein said transmission antenna performs wireless power transmission according to electromagnetic induction with a reception antenna, and said variable resonance frequency circuit matches a resonance condition of said transmission antenna to that of said reception antenna.

7. A resonant type transmission power supply system provided with a plurality of resonant type transmission power supply devices each of that controls supply of electric power to a corresponding one of transmission antennas, in which said transmission antennas operate at one fixed frequency, each of said resonant type transmission power supply devices comprising:

a pulse input circuit to input a pulse voltage to said corresponding transmission antenna at set intervals;

a variable resonance frequency circuit to cause a resonance frequency of said corresponding transmission antenna to be variable and perform sweep detection of the resonance frequency when a pulse voltage is inputted by said pulse input circuit;

a frequency characteristic detecting circuit to detect a frequency characteristic of said corresponding transmission antenna when the sweep detection of the resonance frequency is performed by said variable resonance frequency circuit;

a foreign object detecting circuit to detect presence or absence of a foreign object in an electromagnetic field generated from said corresponding transmission antenna on a basis of a detection result acquired by said frequency characteristic detecting circuit;

a position detecting circuit to, when a foreign object is detected by said foreign object detecting circuit, detect a position of said foreign object on a basis of a detection result acquired by each of said frequency characteristic detecting circuits; and

a plurality of power control circuits each to reduce or stop supply of electric power to said corresponding transmission antenna on a basis of the position of the foreign object detected by said position detecting circuit.