Power receiving device, power transmitting device and control device

• US 9,343,225 B2
• Filed: 12/17/2012
• Issued: 05/17/2016
• Est. Priority Date: 01/13/2012
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Moritsuka, Fumi, Onizuka, Kohei, Otaka, Shoji, Ishihara, Hiroaki
• Primary Examiner(s): Leja, Ronald W
• Application Number:
  US13/717,477
• Publication Number:
  US 20130181537A1
• Time in Patent Office: 1,247 Days
• Field of Search: 307/104
• US Class Current: 1/1
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• 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

There provided a power receiving device connectable with a first load circuit operating according to AC power from a power transmitting device in which the power receiver receives the AC power from the power transmitting device via magnetic coupling, the impedance adjuster is capable of converting at least one of voltage and current of the AC power received at the power receiver, the controller controls increase in output voltage of the power transmitting device, the AC power is supplied to the first load circuit via the impedance adjuster when the first load circuit is connected to the power receiving device, and the controller controls the impedance adjuster such that an input impedance of the impedance adjuster is lower than an input impedance of the first load circuit during at least a part of a time period where the output voltage of the power transmitting device is increased.

Claims

1. A power receiving device connectable with a first load circuit operating according to AC power from a power transmitting device, the power receiving device comprising:

a power receiver to receive the AC power from the power transmitting device via magnetic coupling;

an impedance adjuster capable of converting at least one of voltage and current of the AC power received at the power receiver; and

a controller to control an increase in output voltage of the power transmitting device,

wherein the AC power is supplied to the first load circuit via the impedance adjuster when the first load circuit is connected to the power receiving device, and

wherein the controller controls the impedance adjuster such that an input impedance of the impedance adjuster is lower than an input impedance of the first load circuit during at least a part of a time period in which the output voltage of the power transmitting device is increased.

2. The power receiving device according to claim 1, the power receiving device being connectable with a second load circuit operating according to the AC power received from the power transmitting device, and the power receiving device further comprising:

a switch to switch connection between the impedance adjuster and the second load circuit,

wherein the controller turns on the switch during at least a part of a time period in which the output voltage of the power transmitting device is increased.

3. The power receiving device according to claim 1, wherein the impedance adjuster comprises a switching converter, the switching converter including a plurality of switches and a plurality of capacitive elements, and

wherein the controller adjusts the input impedance of the impedance adjuster by controlling duty cycles of switching of the switches and charge and discharge of the capacitive elements.

4. The power receiving device according to claim 1, wherein the controller increases the input impedance of the impedance adjuster toward a first target value and increases the output voltage of the power transmitting device toward a second target value, and

wherein an increasing rate of the input impedance with respect to the first target value is lower than an increasing rate of the output voltage of the power transmitting device with respect to the second target value.

5. The power receiving device according to claim 1, wherein the power receiving device further comprises the first load circuit, and the first load circuit is a secondary battery.

9. The power receiving device according to claim 1, wherein the controller controls the output voltage of the power transmitting device and controls the impedance adjuster such that the input impedance of the impedance adjuster remains lower than the input impedance of the first load circuit during a time period over which the output voltage of the power transmitting device is increased to a target value, and the input impedance of the impedance adjuster gradually increases over the time period to its target value.

6. A power transmitting device transmitting power to a power receiving device connectable to a load circuit, the power receiving device including a power receiver receiving AC power and an impedance adjuster transmitting the AC power received at the power receiver to the load circuit, the load circuit operating according to the AC power received via the impedance adjuster, and the power transmitting device comprising:

an AC power generator to generate the AC power;

a power transmitter to transmit the AC power to the power receiving device via magnetic coupling with the power receiver; and

a controller to control an increase in output voltage of the AC power generator,

wherein the controller controls the impedance adjuster such that an input impedance of the impedance adjuster is lower than an input impedance of the load circuit during at least a part of a time period in which the output voltage of the AC power generator is increased.

7. The power transmitting device according to claim 6, wherein the controller increases the input impedance of the impedance adjuster toward a first target value and increases the output voltage of the AC power generator toward a second target value, and an increasing rate of the input impedance with respect to the first target value is lower than an increasing rate of the output voltage of the AC power generator with respect to the second target value.

10. The power transmitting device according to claim 6, wherein the controller controls the output voltage of the AC power generator and controls the impedance adjuster such that the input impedance of the impedance adjuster remains lower than the input impedance of the load circuit during a time period over which the output voltage of the AC power generator is increased to a target value, and the input impedance of the impedance adjuster gradually increases over the time period to its target value.

8. A control device controlling a power transmitting device and a power receiving device capable of supplying AC power received from the power transmitting device to a load circuit via an impedance adjuster in the power receiving device,

wherein the control device controls an increase in output voltage of the power transmitting device, and controls the impedance adjuster such that an input impedance of the impedance adjuster is lower than an input impedance of the load circuit during at least a part of a time period in which the output voltage of the power transmitting device is increased.

11. The control device according to claim 8, wherein the control device controls the output voltage of the power transmitting device and controls the impedance adjuster such that the input impedance of the impedance adjuster remains lower than the input impedance of the load circuit during a time period over which the output voltage of the power transmitting device is increased to a target value, and the input impedance of the impedance adjuster gradually increases over the time period to its target value.