Wireless power transmitter and method of error detection during use thereof

• US 10,361,566 B2
• Filed: 10/01/2015
• Issued: 07/23/2019
• Est. Priority Date: 10/02/2014
• Status: Active Grant

• Current Assignee: Powermat Technologies, Ltd.
• Original Assignee: Powermat Technologies, Ltd.
• Inventors: Gluzman, Ilya, Greenwald, Oola, Mach, Elieser, Moshkovich, Oz, Raveh, Guy
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Pham, Duc M
• Application Number:
  US15/517,358
• Publication Number:
  US 20170294783A1
• Time in Patent Office: 1,391 Days
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 7/00036 Charger exchanging data with battery
• CPC Class Codes: H02J 7/00047 with provisions for charging different types of batteries
• CPC Class Codes: H04B 5/24 Inductive coupling
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A wireless power transmitter is provided for power transmission to a wireless power receiver. The transmitter comprises a primary coil to transfer power to a secondary coil of the wireless power receiver, a power supply, a driver to provide an electric potential from the power supply to the primary coil, a monitoring system to measure electrical flow parameters of the primary coil, and to filter the measured electrical flow parameters thereby producing a response signal, and a controller to direct operation of the wireless power transmitter. The controller is configured to perform error checking by directing the driver to provide the electric potential as a superposition of a transmission signal and a sensing signal, the filter characteristics comprising electrical flow parameters of the and sensing signal, and detecting, based a difference between the response and sensing signals, an error condition indicative of a foreign object.

Claims

1. A wireless power transmitter for power transmission to a wireless power receiver, the wireless power transmitter comprising:

a primary coil to transfer power to a secondary coil of said wireless power receiver;

a power supply;

a driver to provide an electric potential from said power supply to said primary coil;

a monitoring system to measure electrical flow parameters of said primary coil, and to filter the measured electrical flow parameters based on one or more filter characteristics, thereby producing a response signal; and

a controller to direct operation of the wireless power transmitter,

wherein the controller is configured to perform error checking by;

directing said driver to provide said electric potential as a superposition of a transmission signal and a sensing signal, said filter characteristics comprising electrical flow parameters of one of said transmission and sensing signals; and

detecting, based a difference between one or more electrical flow parameters of said response signal and of the other of said transmission and sensing signals, an error condition indicative of a foreign object between said primary and secondary coils.

2. The wireless power transmitter according to claim 1, wherein the frequency of said sensing signal is substantially different from the frequency of said transmission signal.

3. The wireless power transmitter according to claim 1, wherein said filter characteristics comprise electrical flow parameters of said transmission signal.

4. The wireless power transmitter according to claim 1, wherein the frequency of said sensing signal is constant.

5. The wireless power transmitter according to claim 1, wherein said controller is configured to vary the frequency of said transmission signal during the power transmission.

6. The wireless power transmitter according to claim 1, wherein said controller is further configured to facilitate, when said error condition is detected, interrupting said electrical potential to said primary coil.

7. The wireless power transmitter according to claim 6, wherein the facilitating comprises directing said driver to cease providing said electric potential.

8. The wireless power transmitter according to claim 1, wherein said controller is configured to perform said error checking in an ongoing manner during the power transmission.

9. The wireless power transmitter according to claim 1, wherein said controller is configured to perform said error checking at intervals during the power transmission.

10. The wireless power transmitter according to claim 1, wherein said controller comprises a comparator.

11. A method of detecting an error condition, indicative of a foreign object between a wireless power transmitter and a wireless power receiver, said wireless power transmitter comprising a primary coil for transferring power wirelessly to a secondary coil of said wireless power receiver, the method comprising:

providing an electric potential, being a superposition of a transmission signal and a sensing signal, to said primary coil;

measuring electrical flow parameters of said primary coil;

filtering the measured electrical flow parameters based on one or more filter characteristics, thereby producing a response signal;

comparing one or more electrical flow parameters of the response signal with corresponding electrical flow parameters of one of said transmission and sensing signals; and

determining, based on said comparing, whether or not said error condition exists.

12. The method according to claim 11, wherein the frequency of said sensing signal is substantially different from the frequency of said transmission signal.

13. The method according to claims 11, wherein said filter characteristics comprise electrical flow parameters of said transmission signal.

14. The method according to claim 11, wherein the frequency of said sensing signal is constant.

15. The method according to claim 11, wherein the frequency of said transmission signal varies during the power transmission.

16. The method according to claim 11, further comprising, when said error condition is detected, interrupting said electrical potential to said primary coil.

17. The method according to claim 11, wherein said error checking is performed in an ongoing manner during the power transmission.

18. The method according to claim 11, wherein said error checking is performed continuously during the power transmission.

19. The method according to claim 11, wherein said error checking is performed at intervals during the power transmission.

20. The method according to claim 11, wherein said wireless power transmitter further comprises a comparator.