Power transmitting device and wireless power transmission system

• US 10,305,327 B2
• Filed: 08/07/2017
• Issued: 05/28/2019
• Est. Priority Date: 05/26/2014
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Inventors: Oosumi, Hideo, Kanno, Hiroshi, Yamamoto, Hiroshi, Sakata, Tsutomu
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Pham, Duc M
• Application Number:
  US15/670,371
• Publication Number:
  US 20170338694A1
• Time in Patent Office: 659 Days
• CPC Class Codes: H02J 50/10 using inductive coupling
• 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
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge

Abstract

A control method for a power transmitting device is provided, the power transmitting device including a power transmitting antenna, which transmits AC power wirelessly to the power receiving antenna of a power receiving device, and an oscillator. The method includes supplying pulse signals that control first and second switching element groups to the oscillator, and changing a phase shift amount between a first pulse signal and a second pulse signal. The method also includes causing the oscillator to change the voltage of the AC power output and to set an initial value of the phase shift amount. The method further includes causing the oscillator to output preliminary AC power of a voltage to reduce the phase shift amount from the initial value, fixing the phase shift amount, and causing the oscillator to output the AC power while maintaining the voltage corresponding to the fixed phase shift amount.

Claims

1. A control method of a power transmitting device, the power transmitting device including a power transmitting antenna that transmits AC power wirelessly to the power receiving antenna of a power receiving device;

an oscillator that includes (i) a first switching element group connected to a high potential terminal of DC power supply, (ii) a second switching element group connected to a low potential terminal of the DC power supply, (iii) a first terminal connected to the first switching element group, and (iv) a second terminal connected to the second switching element groups, wherein the oscillator converts DC power of the DC power supply into the AC power, by using the first and second switching element groups, and outputs the AC power to the power transmitting antenna via the first terminal and the second terminal; and

a communication circuit that receives signals from the power receiving device, the method comprising;

supplying pulse signals that control the first and second switching element groups to the oscillator;

changing a phase shift amount between a first pulse signal and a second pulse signal, the first pulse signal supplied to one of the first and second switching element groups, and the second pulse signal supplied to the other one of the first and second switching element groups;

causing the oscillator to change the voltage of the AC power output;

setting an initial value of the phase shift amount when a current flowing through the power transmitting antenna exceeds a predetermined value after the power transmitting antenna transmits the AC power to the power receiving antenna;

causing the oscillator to output preliminary AC power of a voltage corresponding to the initial value of the phase shift amount, to reduce the phase shift amount from the initial value, and to output preliminary AC power of each voltage corresponding to each of the reduced phase shift amounts;

fixing the phase shift amount when the communication circuit receives a first response signal indicating an activation of a control circuitry in the power receiving device in order to wait for reception of a second response signal indicating a maximum power set in the power receiving device; and

causing the oscillator to output the AC power while maintaining the voltage corresponding to the fixed phase shift amount.

2. The control method of the power transmitting device according to claim 1,

wherein the first response signal includes a signal strength packet specified by the Qi standard of WPC (wireless power consortium).

3. The control method of the power transmitting device according to claim 2,

wherein the signal strength packet includes a signal strength value indicating a voltage corresponding to a phase shift amount upon activation of the control circuitry in the power receiving device.

4. The control method of the power transmitting device according to claim 1,

wherein the second response signal includes a configuration packet specified by the Qi standard of WPC (wireless power consortium).

5. The control method of the power transmitting device according to claim 1, further comprising:

waiting for a third response signal indicating a manufacturer ID of the power receiving device to be transmitted from the power receiving device after the second response signal.

6. The control method of the power transmitting device according to claim 5,

wherein the third response signal includes an identification packet specified by the Qi standard of WPC (wireless power consortium).

7. The control method of the power transmitting device according to claim 5, further comprising:

waiting for a fourth response signal to be transmitted from the power receiving device after the third response signal, the fourth response signal including a control error value indicating a difference value between a required voltage value of the power receiving device and a voltage value of the AC power from the power transmitting antenna.

8. The control method of the power transmitting device according to claim 7,

wherein the fourth response signal includes a control error packet specified by the Qi standard of WPC (wireless power consortium).

9. The control method of the power transmitting device according to claim 7, further comprising:

upon receipt of the fourth response signal, reducing the difference value, which is indicated by the control error signal included in the fourth response signal, close to zero by changing the voltage of the AC power based on a change in the phase shift amount.