Power transmitting device, power receiving device, power supply system, and power supply method

• US 10,069,347 B2
• Filed: 04/21/2017
• Issued: 09/04/2018
• Est. Priority Date: 03/27/2013
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Nakano, Daiju, Ohba, Nobuyuki, Takano, Kohji
• Primary Examiner(s): Barnie, Rexford
• Assistant Examiner(s): Ly, Xuan
• Application Number:
  US15/493,354
• Publication Number:
  US 20170222487A1
• Time in Patent Office: 501 Days
• Field of Search: 307104
• CPC Class Codes: G01R 29/0878 Sensors; antennas; probes; detectors wave guide measuring sections G01R1/24
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/20 using microwaves or radio frequency waves
• CPC Class Codes: H02J 50/30 using light, e.g. lasers
• 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: H04B 10/07955 Monitoring or measuring power
• CPC Class Codes: H04B 10/807 Optical power feeding, i.e. transmitting power using an optical signal
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

Provided are a power transmitting device, a power receiving device, a power supply system, and a power supply method able to supply electric power by emitting electromagnetic waves. A power transmitting device comprises: a calculating unit for calculating the maximum value for the emitted output of electromagnetic waves meeting exposure standards on the basis of a response delay time measured by the communication link between the power transmitting device and a power receiving device; a power transmitting unit for transmitting power via a power supply link with the power receiving device at an output not exceeding the maximum value; an anomaly detecting unit for detecting an anomaly in the power supply link on the basis of communication with the power receiving device via the communication link; and an output control unit for controlling the output on the basis of the detection of an anomaly in the power supply link.

Claims

1. A power transmitting device able to transmit power to a power receiving device by emitting electromagnetic waves, the power transmitting device comprising:

a calculating unit for calculating a maximum value for an emitted output of electromagnetic waves meeting exposure standards on a basis of a response delay time measured by a wireless communication link between the power transmitting device and the power receiving device;

a power transmitting unit for transmitting power via a power supply link with the power receiving device at an output not exceeding the maximum value;

an anomaly detecting unit for detecting anomalies in the power supply link on the basis of communication with the power receiving device via the wireless communication link, wherein the anomaly detecting unit is configured to compare an amount of received power acquired from a photoelectric converter to the amount of power transmitted by the power transmitting unit, wherein the transmitted power is reported by the power transmitting device, wherein the anomaly detecting unit is further configured to determine a numerical value from the comparison, and wherein a numerical value greater than or equal to a predetermined threshold represents that an anomaly has occurred within the power supply link; and

an output control unit for limiting the output on the basis of a detection of an anomaly in the power supply link.

2. The power transmitting device according to claim 1, wherein the emitted output of electromagnetic waves has directionality, the calculating unit calculates the maximum value for the emitted output of electromagnetic waves on a basis of conditions preventing a predetermined exposure level from being exceeded when electromagnetic waves are emitted at a maximum value over a reaction period at least including the response delay time, and the output control unit stops the emitted output of electromagnetic waves in the power supply link in response to the detection of the anomaly in the power supply link.

3. The power transmitting device according to claim 2, wherein the anomaly detecting unit detects the occurrence of the anomaly in the power supply link by notification received from the power receiving device via the wireless communication link.

4. The power transmitting device according to claim 1, wherein the calculating unit repeatedly evaluates the response delay time in communication via the wireless communication link and calculates the maximum value on the basis of an evaluated response delay time, and the power transmitting unit transmits power via the power supply link on a basis of a latest calculated maximum value.

5. The power transmitting device according to claim 1, wherein the wireless communication link has directionality, and the power transmitting device comprises an initial alignment unit for aligning the power supply link via establishment of the wireless communication link, and a subsequent alignment unit for adjusting an alignment of the power supply link on the basis of an amount of power received by the power receiving device via the power supply link as communicated via the wireless communication link.

6. The power transmitting device according to claim 1, wherein the emitted output of electromagnetic waves is laser emission, and the wireless communication link is a millimeter wave wireless communication link.

7. A power receiving device able to receive electric power supplied from a power transmitting device by emitting electromagnetic waves, the power receiving device comprising:

a communication device able to communicate so as to establish a response delay time in communication via a wireless communication link between the power receiving device and the power transmitting device;

a power receiving device for receiving electric power supplied via a power supply link with the power transmitting device at an emission output of electromagnetic waves not exceeding a maximum value meeting exposure standards, in accordance with the response delay time;

an anomaly detecting unit that is configured to compare an amount of received power acquired from a photoelectric converter to the amount of power transmitted by the power transmitting unit, wherein the transmitted power is reported by the power transmitting device, wherein the anomaly detecting unit is further configured to determine a numerical value from the comparison, and wherein a numerical value greater than or equal to a predetermined threshold represents that an anomaly has occurred within the power supply link; and

a power receiving amount acquiring unit for acquiring the amount of power received by the power receiving device in order to limit the output from the power transmitting device in response to an anomaly occurring in the power supply link.

8. The power receiving device of claim 7, wherein the emission, by the power transmitting device, of electromagnetic waves is laser emission, wherein the power receiving device includes the photoelectric conversion element that receives the emitted laser beam by photoelectrically converting the received laser beam to generate electromotive force, and wherein the power supply link is established between the laser power transmitting device and the laser power receiving device by aligning the laser emission direction so that the laser beam emitted by a laser element is properly incident on the photoelectric conversion element.

9. The power receiving device of claim 8, wherein the photoelectric conversion element is a photodiode having high conversion efficiency with respect to a wavelength of the laser emitted by a laser emitter for power transmission.

10. The power receiving device of claim 8, wherein the photoelectric conversion element is a solar cell having high conversion efficiency with respect to a wavelength of the laser emitted by a laser emitter for power transmission.

11. A power supply system including a power transmitting device able to transmit power by emitting electromagnetic waves, and a power receiving device able to receive power supplied by the power transmitting device, the power supply system comprising:

a calculating unit for calculating a maximum value for an emitted output of electromagnetic waves meeting exposure standards on the basis of a response delay time measured by a wireless communication link between the power transmitting device and the power receiving device;

a power transmitting unit in the power transmitting device for transmitting power via a power supply link with the power receiving device at an output not exceeding the maximum value;

an anomaly detecting unit for detecting anomalies in the power supply link on the basis of communication with the power receiving device via the wireless communication link, wherein the anomaly detecting unit is further for comparing an amount of received power acquired from a photoelectric converter to the amount of power transmitted by the power transmitting unit, wherein the transmitted power is reported by the power transmitting device, wherein the anomaly detecting unit is further configured to determine a numerical value from the comparison, and wherein a numerical value greater than or equal to a predetermined threshold represents that an anomaly has occurred within the power supply link; and

an output control unit in the power transmitting device for limiting the output on a basis of a detection of an anomaly in the power supply link.

12. The power supply system of claim 11, wherein the emission, by the power transmitting device, of electromagnetic waves is laser emission, and wherein the power receiving device includes the photoelectric conversion element and receives a laser beam emitted by the laser power transmitting device via the photoelectric conversion element, further comprising:

a first antenna attached to the power receiving device; and

a second antenna attached to the power transmitting device, wherein the first antenna and the second antenna are configured to establish wireless data communication via the wireless communication link.

13. A power supply method executed between a power transmitting device able to transmit power by emitting electromagnetic waves, and a power receiving device able to receive power supplied by the power transmitting device, the power supply method comprising the steps of:

evaluating a response delay time for communication via a wireless communication link between the power transmitting device and the power receiving device;

calculating a maximum value for an emitted output of electromagnetic waves meeting exposure standards on the basis of the response delay time; and

causing, by an output control unit, the power transmitting unit to transmit power via a power supply link with the power receiving device at an output not exceeding the maximum value;

the power supply method further comprising the steps of;

detecting, by an anomaly detecting unit, the anomaly in the power supply link on the basis of communication with the power receiving device via the wireless communication link,

comparing, by the anomaly detecting unit, an amount of received power acquired from a photoelectric converter for power reception to the amount of power transmitted by the power transmitting unit, wherein the transmitted power is reported by the power transmitting device;

determining, by the anomaly detecting unit, a numerical value from the comparison, wherein a numerical value greater than or equal to a predetermined threshold represents that an anomaly has occurred within the power supply link; and

causing the power supply device to limit the output of the power supply link on the basis of the detection of the anomaly in the power supply link.

14. The power supply method according to claim 13, wherein the emission of electromagnetic waves has directionality, the calculating step includes calculating the maximum value for the emission output of electromagnetic waves on the basis of conditions preventing a predetermined exposure level from being exceeded when electromagnetic waves are emitted at a maximum value over a reaction period at least including the response delay time, and the output limiting step includes causing the power transmitting device to stop the emission output of electromagnetic waves in the power supply link in response to the detection of the anomaly in the power supply link.

15. The power supply method according to claim 14, wherein the anomaly detecting step further comprises the steps of causing the power transmitting device to transmit the amount of power transmitted by the power transmitting device to the power receiving device via a communication device, causing the power receiving device to detect any anomaly occurring in the power supply link on the basis of a comparison of the amount of power transmitted to the amount of power received by the power receiving device, and causing the power receiving device to notify the power transmitting device of any detected anomaly.

16. The power supply method according to claim 13, wherein the wireless communication link has directionality, and the power supply method, prior to the power transmitting step, further comprises the steps of:

initially aligning the power supply link via establishment of the wireless communication link, and adjusting an alignment of the power supply link on the basis of an amount of power received by the power receiving device via the power supply link as communicated via the wireless communication link.

17. The power supply method of claim 13, wherein the emission, by the power transmitting device, of electromagnetic waves is laser emission, and wherein the power receiving device includes the photoelectric conversion element and receives a laser beam emitted by the laser power transmitting device via the photoelectric conversion element, further comprising:

receiving, by a load attached externally to the power receiving device, the emitted laser beam, wherein the load is a secondary battery.

18. The power supply method of claim 13, wherein the emission, by the power transmitting device, of electromagnetic waves is laser emission, and wherein the power receiving device includes the photoelectric conversion element and receives a laser beam emitted by the laser power transmitting device via the photoelectric conversion element, further comprising:

receiving, by a load attached internally to the power receiving device, the emitted laser beam, wherein the load is a monitoring camera.