WIRELESS POWER TRANSFER METERING

• US 20190011523A1
• Filed: 07/09/2018
• Published: 01/10/2019
• Est. Priority Date: 07/07/2017
• Status: Active Grant

• Current Assignee: University of Michigan
• Original Assignee: The Regents of The University of Michigan Univers ITY of Michigan Office of Technology Transfer
• Inventors: Avestruz, Al-Thaddeus, Haney, Spencer, Chu, Sung Yul
• Granted Patent: US 10,732,251 B2
• Time in Patent Office: Days
• CPC Class Codes: G01R 15/142 Arrangements for simultaneous measurements of several parameters employing techniques covered by groups G01R15/14 - G01R15/26
• CPC Class Codes: G01R 15/16 using capacitive devices
• CPC Class Codes: G01R 15/18 using inductive devices, e.g. transformers
• CPC Class Codes: G01R 21/002 Measuring real component
• CPC Class Codes: G01R 21/133 by using digital technique
• CPC Class Codes: G01R 35/005 Calibrating; Standards or reference devices, e.g. voltage or resistance standards, "golden" references G01R33/0035, G01R35/002 take precedence
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices

Abstract

A system measures wireless power transfer between a transmitter and a receiver. The system includes a sensor circuit including a sensor. The sensor is configured and positioned to generate sensor data indicative of a field. The field is generated in connection with the wireless power transfer. The system further includes a processor coupled to the sensor circuit and configured to determine a power measurement based on the sensor data. The processor is further configured to determine misalignment of the transmitter or the receiver. The processor is also configured to correct an estimate of the power measurement based on the misalignment.

Claims

1. A system for measuring wireless power transfer between a transmitter and a receiver, the system comprising:

a sensor circuit comprising a sensor, the sensor being configured and positioned to generate sensor data indicative of a field, the field generated in connection with the wireless power transfer; and

a processor coupled to the sensor circuit and configured to determine a power measurement based on the sensor data.

2. The system of claim 1, wherein the sensor is positioned between the transmitter and the receiver.

3. The system of claim 1, wherein the sensor circuit comprises a plurality of sensors configured and positioned to generate sensor data indicative of the field, the plurality of sensors comprising the sensor.

4. The system of claim 3, wherein the processor is configured to determine the power measurement using pair-wise products of the plurality of sensors.

5. The system of claim 3, wherein each sensor of the plurality of sensors includes a respective capacitive sense plate such that the field is an electric field.

6. The system of claim 1, wherein the sensor comprises a sense coil.

7. The system of claim 1, wherein the field comprises a magnetic field.

8. The system of claim 1, wherein the processor is further configured to determine a misalignment of the transmitter or the receiver, and to correct an estimate of the power measurement based on the misalignment.

9. The system of claim 1, wherein the power measurement is indicative of real power.

10. The system of claim 1, wherein the processor is configured to determine the power measurement via frequency domain computations.

11. The system of claim 1, wherein the processor is configured to determine the power measurement via binning in the frequency domain.

12. The system of claim 1, wherein the processor is configured to determine the power measurement via time domain computations.

13. A method of measuring wireless power transfer between a transmitter and a receiver, the method comprising:

capturing field data with a sensor configured and positioned to generate sensor data indicative of a field, the field generated in connection with the wireless power transfer; and

determining a power measurement based on the field data.

14. The method of claim 13, further comprising positioning the sensor between the transmitter and the receiver.

15. The method of claim 13, wherein determining the power measurement comprises determining a misalignment of the transmitter or the receiver.

16. The method of claim 15, wherein determining the power measurement further comprises correcting the power measurement based on the misalignment.

17. The method of claim 13, wherein determining the power measurement comprises binning in the frequency domain.

18. A method of calibrating a wireless power transfer measurement device, the method comprising:

positioning a test receiver relative to a transmitter and the wireless power transfer measurement device;

capturing field data for a load impedance with the wireless power transfer measurement device;

determining a power measurement based on the field data; and

determining a plurality of calibration factors for the wireless power transfer measurement device based on the power measurement.

19. The method of claim 18, wherein capturing the field data comprises varying a load impedance of the test receiver.

20. The method of claim 18, wherein capturing the field data comprises varying a load resistance of the test receiver.

21. The method of claim 18, wherein determining the plurality of calibration factors comprises performing an optimization to minimize measurement error.

22. The method of claim 18, wherein determining the plurality of calibration factors comprises performing a least squares approximation.

23. The method of claim 18, wherein capturing the field data comprises positioning multiple sense coils relative to a transmitter and the wireless power transfer measurement device.

24. The method of claim 23, wherein capturing the field data comprises approximating a misalignment over multiple positions of the multiple sense coils.

25. The method of claim 23, wherein determining the power measurement comprises using pair-wise products of the multiple sense coils.