Methods for steering a magnetic field for smart wireless power transmission

• US 10,320,201 B2
• Filed: 02/08/2018
• Issued: 06/11/2019
• Est. Priority Date: 11/07/2014
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Tillotson, Brian J., Zeng, Peng
• Primary Examiner(s): Kim, Jung
• Application Number:
  US15/891,446
• Publication Number:
  US 20180175632A1
• Time in Patent Office: 488 Days
• CPC Class Codes: G01B 7/30 for measuring angles or tapers; for testing the alignment of axes
• CPC Class Codes: G01R 19/04 Measuring peak values or amplitude or envelope of ac or of pulses
• CPC Class Codes: H01F 2005/027 wound on formers for receiving several coils with perpendicular winding axes, e.g. for antennae or inductive power transfer
• 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 50/005 Mechanical details of housing or structure aiming to accommodate the power transfer means, e.g. mechanical integration of coils, antennas or transducers into emitting or receiving devices
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• 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 5/263 Multiple coils at either side
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

Systems and methods for mitigating constraints associated with wireless power transmission in applications where the position and orientation of the desired magnetic field changes over time, for example, because the position and orientation of the receiver being powered changes over time or because different receivers having different positions and orientations are being powered at different times. In accordance with some embodiments, the system employs a plurality of wireless power transmitters in a defined space, each transmitter consisting of individual coils oriented orthogonally relative to each other. Using field interference amongst these individual coils as well as amongst the transmitters they form, one can actively control the wireless power field intensity and orientation at any given point in the defined space. This allows for methods to steer the power transmission towards a specific target at a specific angle.

Claims

1. A system for wireless power transmission comprising:

a receiver coil having an axis;

a gimbal arrangement;

a transmitter coil having an axis and mounted to the gimbal arrangement;

a first actuator coupled to the gimbal arrangement for changing an azimuth angle of the axis of the transmitter coil;

a second actuator coupled to the gimbal arrangement for changing an elevation angle of the axis of the transmitter coil;

read-only memory storing unit vectors of each magnetic field at any given position in a defined space;

a computer system programmed to control the first and second actuators and an amplitude of current to be supplied to the transmitter coil to generate a resultant magnetic field having a magnetic field line which is located along the axis of the receiver coil; and

a current source for supplying current having the respective amplitude to the transmitter coil,

wherein the computer system is further programmed to receive location data representing the position and orientation of the receiver coil, retrieve unit vectors from the read-only memory look-up table, and determine the amplitude required to multiply each unit vector in order to achieve a desired orientation and intensity of the resultant magnetic field.

2. The system as recited in claim 1, wherein the receiver coil is a winding of an electric motor.

3. The system as recited in claim 2, wherein the computer system is programmed to generate amplitude and frequency commands representing an amplitude and a frequency of an alternating electric current to be supplied to the transmitter coil.

4. The system as recited in claim 3, wherein the computer system is programmed to determine a location of the electric motor relative to a frame of reference and then generate control signals to control the first and second actuators in dependence on the position of the receiver coil and the orientation of the axis of the receiver coil.

5. The system as recited in claim 3, wherein the current source comprises:

a power regulator that receives the amplitude command from the computer system and outputs a direct electric current having the amplitude; and

a variable frequency drive circuit that receives the frequency command from the computer system and receives the direct electric current from the power regulator, converts the direct electric current into an alternating electric current with the frequency, and supplies the alternating electrical current having the amplitude and frequency to the transmitter coil.

6. The system as recited in claim 3, wherein the position and orientation of the electric motor are fixed in the frame of reference, and the computer system is programmed to retrieve the amplitude and frequency from a look-up table.

7. A system for wireless power transmission comprising:

a receiver coil having an axis, wherein the receiver coil is a winding of an electric motor;

a gimbal arrangement;

a transmitter coil having an axis and mounted to the gimbal arrangement;

a first actuator coupled to the gimbal arrangement for changing an azimuth angle of the axis of the transmitter coil;

a second actuator coupled to the gimbal arrangement for changing an elevation angle of the axis of the transmitter coil;

a computer system programmed to control the first and second actuators and an amplitude of current to be supplied to the transmitter coil to generate a resultant magnetic field having a magnetic field line which is located along the axis of the receiver coil by generating amplitude and frequency commands representing an amplitude and a frequency of an alternating electric current to be supplied to the transmitter coil; and

a current source for supplying current having the respective amplitude to the transmitter coil, wherein the current source comprises;

a power regulator that receives the amplitude command from the computer system and outputs a direct electric current having the amplitude; and

a variable frequency drive circuit that receives the frequency command from the computer system and receives the direct electric current from the power regulator, converts the direct electric current into an alternating electric current with the frequency, and supplies the alternating electrical current having the amplitude and frequency to the transmitter coil.

8. The system as recited in claim 7, wherein the computer system is programmed to determine a location of the electric motor relative to a frame of reference and then generate control signals to control the first and second actuators in dependence on the position of the receiver coil and the orientation of the axis of the receiver coil.

9. The system as recited in claim 7, wherein the position and orientation of the electric motor are fixed in the frame of reference, and the computer system is programmed to retrieve the amplitude and frequency from a look-up table.

10. A system for wireless power transmission comprising:

a receiver coil having an axis;

a gimbal arrangement;

a transmitter coil having an axis and mounted to the gimbal arrangement;

a first actuator coupled to the gimbal arrangement for changing an azimuth angle of the axis of the transmitter coil;

a second actuator coupled to the gimbal arrangement for changing an elevation angle of the axis of the transmitter coil;

a computer system programmed to control the first and second actuators and an amplitude of current to be supplied to the transmitter coil to generate a resultant magnetic field having a magnetic field line which is located along the axis of the receiver coil; and

a current source for supplying current having the respective amplitude to the transmitter coil,

wherein the computer system is further programmed to use location data representing the position and orientation of the receiver coil and unit vectors of each magnetic field at any given position in a defined space to determine the amplitude required to multiply each unit vector in order to achieve a desired orientation and intensity of the resultant magnetic field.

11. The system as recited in claim 10, wherein the receiver coil is a winding of an electric motor.

12. The system as recited in claim 11, wherein the computer system is programmed to generate amplitude and frequency commands representing an amplitude and a frequency of an alternating electric current to be supplied to the transmitter coil.

13. The system as recited in claim 12, wherein the computer system is programmed to determine a location of the electric motor relative to a frame of reference and then generate control signals to control the first and second actuators in dependence on the position of the receiver coil and the orientation of the axis of the receiver coil.

14. The system as recited in claim 12, wherein the current source comprises:

a power regulator that receives the amplitude command from the computer system and outputs a direct electric current having the amplitude; and

a variable frequency drive circuit that receives the frequency command from the computer system and receives the direct electric current from the power regulator, converts the direct electric current into an alternating electric current with the frequency, and supplies the alternating electrical current having the amplitude and frequency to the transmitter coil.