Wireless power transmission device and method for controlling power supply for wireless power transmission device

• US 9,343,909 B2
• Filed: 06/06/2014
• Issued: 05/17/2016
• Est. Priority Date: 07/29/2013
• Status: Expired due to Fees

• Current Assignee: Nitto Denko Corporation
• Original Assignee: Nitto Denko Corporation
• Inventors: Tsuda, Hisashi, Hatanaka, Takezo
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Kessie, Daniel
• Application Number:
  US14/424,636
• Publication Number:
  US 20150263530A1
• Time in Patent Office: 711 Days
• Field of Search: 307/104
• US Class Current: 1/1
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 7/00712 the cycle being controlled or terminated in response to electric parameters

Abstract

A wireless power transmission apparatus 1 includes a power-supplying module 2, a power-receiving module 3, a phase detector 4, and a control device 5, and is set so that its transmission characteristic with respect to the power-source frequency has a double-hump characteristic. The control device 5 determines whether to supply power to the power-supplying module 2, based on variation in the phase of the input impedance Z_in in the power-supplying state and that in the standby state, which is detected by a phase detector 4.

Claims

1. A wireless power transmission apparatus configured to supply power from a power-supplying module connected to a power source to a power-receiving module by means of resonance phenomenon, wherein:

the power-supplying module includes

a phase detector configured to detect the phase of an input impedance, and

a control device configured to control power to be supplied to the power-supplying module;

wherein the power-supplying module and the power-receiving module are each set so that a transmission characteristic with respect to a power-source frequency of the power supplied to the power-supplying module has a double-hump characteristic such that a peak occurs in a power-source frequency band lower than a resonance frequency of the power-supplying module and the power-receiving module, and in a power-source frequency band higher than the resonance frequency; and

wherein the control device determines whether to supply power to the power-supplying module, based on a difference between phases of the input impedances in a standby state and in a power-supplying state, the standby state being a state in which power is not supplied from the power-supplying module to the power-receiving module, the power-supplying state being a state in which power is supplied from the power-supplying module to the power-receiving module, and the phases being detected by the phase detector.

2. The wireless power transmission apparatus, according to claim 1, wherein

the power-supplying module and the power-power-receiving module comprise a power-supplying coil, a power-supplying resonator, a power-receiving resonator, and a power-power-receiving coil, respectively,

the power-supplying coil is constituted by an RL circuit including a resistor R₁ and a coil L₁,

the power-supplying resonator is constituted by an RLC circuit whose elements include a resistor R₂, a coil L₂, and a capacitor C₂,

the power-receiving resonator is constituted by an RLC circuit whose elements include a resistor R₃, a coil L₃, and a capacitor C₃, and

the power-receiving coil is constituted by an RL circuit including a resistor R₄ and a coil L₄.

4. The wireless power transmission apparatus according to claim 1, wherein

the power-supplying module and the power-power-receiving module comprise a power-supplying coil, a power-supplying resonator, a power-receiving resonator, and a power-power-receiving coil, respectively,

the power-supplying coil is constituted by an RLC circuit including a resistor R₁, a coil L₁, and a capacitor C₁,

the power-supplying resonator is constituted by an RLC circuit whose elements include a resistor R₂, a coil L₂, and a capacitor C₂,

the power-receiving resonator is constituted by an RLC circuit whose elements include a resistor R₃, a coil L₃, and a capacitor C₃, and

the power-receiving coil is constituted by an RLC circuit whose elements include a resistor R₄, a coil L₄, and a capacitor C₄ wherein the power-supplying coil is an RLC serial circuit, at least one of relations K₁₂ ≠

K₂₃ and f1 ≠

f0 is satisfied, where K₁₂ is a coupling coefficient between the coil L₁ and the coil L₂, K₂₃ is a coupling coefficient between the coil L₂ and the coil L₃, a f1 is a resonance frequency of the power-supplying coil, and f0 is a resonance frequency of the power-supplying resonator and the power-receiving resonator.

3. A supply power control method of a wireless power transmission apparatus configured to supply power from a power-supplying module connected to a power source to a power-receiving module by means of resonance phenomenon, wherein the power-supplying module includes a phase detector configured to detect the phase of an input impedance, and a control device configured to control power to be supplied to the power-supplying module;

wherein the power-supplying module and the power-receiving module are each set so that a transmission characteristic with respect to a power-source frequency of the power supplied to the power-supplying module has a double-hump characteristic such that a peak occurs in a drive frequency band lower than a resonance frequency of the power-supplying module and the power-receiving module, and in a drive frequency band higher than the resonance frequency, the method comprising the step of the control device determining whether to supply power to the power-supplying module, based on a difference between phases of the input impedances in a standby state and in a power-supplying state, the standby state being a state in which power is not supplied from the power-supplying module to the power-receiving module, the power-supplying state being a state in which power is supplied from the power-supplying module to the power-receiving module, and the phases being detected by the phase detector.