US-20260128621-A1 - COMMUNICATION PROTOCOL IN A WIRELESS POWER SYSTEM

Abstract

This disclosure provides systems, methods and apparatuses for communication protocol enhancements in a wireless power system. Various implementations relate generally to messages for a communication protocol in a wireless power system. The communication protocol and related aspects address unexpected conditions of a Power Transmitter or a Power Receiver in a wireless power system.

Inventors

• Jayanti Ganesh
• Viswanathan Kanakasabai
• Subbarao Tatikonda
• Suma Memana Narayana Bhat

Assignees

• DOLBY INTELLECTUAL PROPERTY LICENSING, LLC

Dates

Publication Date

20260507

Application Date

20231012

Priority Date

20221012

Claims (20)

1. 1 . A method of a Power Transmitter (PTx) in a wireless power system, the method comprising: performing a first power negotiation with a Power Receiver before a power transfer phase; communicating a suggested negotiation value to the Power Receiver as part of the first power negotiation; receiving a Requested Power negotiation value from the Power Receiver, wherein the Requested Power negotiation value is based on the suggested negotiation value; and indicating that the Power Transmitter accepts the Requested Power negotiation value; and establishing a first Guaranteed Power based on acceptance of the Requested Power negotiation value.
2. 2 . The method of claim 1 , wherein the suggested negotiation value is based on a highest Guaranteed Power that the Power Transmitter can negotiate with the Power Receiver based on prevailing operating conditions of the Power Transmitter.
3. 3 . The method of claim 1 , further comprising: receiving a negotiation value request message from the Power Receiver; and communicating the suggested negotiation value to the Power Receiver in response to the negotiation value request message.
4. 4 . The method of claim 1 , further comprising: transferring power from the Power Transmitter to the Power Receiver during a power transfer phase after the first power negotiation; receiving a power control message from the Power Receiver, the power control message indicating a requested power level; determining that the requested power level would cause the Power Transmitter to exceed a current or power limit of the Power Transmitter or that the Power Transmitter cannot satisfy the first Guaranteed Power established in the first power negotiation; and initiating a second power negotiation to establish a second Guaranteed Power to replace the first Guaranteed Power.
5. 5 . The method of claim 4 , wherein initiating the second power negotiation includes: ending power transfer to the Power Receiver; and communicating a message to cause the Power Receiver to transition from the power transfer phase to a connected phase.
6. 6 . The method of claim 4 , further comprising: communicating a new suggested power negotiation value during the second power negotiation, wherein the new suggested power negotiation value indicates the second Guaranteed Power that the Power Transmitter can support based on current operating conditions of the Power Transmitter.
7. 7 . The method of claim 1 , further comprising: transferring power to the Power Receiver during the power transfer phase; detecting, based on measurements at the Power Transmitter, that a misalignment condition is causing the Power Transmitter to operate above a PTx limit or preventing the Power Transmitter from satisfying the first Guaranteed Power at the PTx limit; and communicating a warning message to indicate the misalignment condition.
8. 8 . The method of claim 7 , wherein detecting the misalignment condition includes: measuring a coupling factor (k-factor) between the Power Transmitter and the Power Receiver; and determining that the k-factor is not within a threshold range.
9. 9 . The method of claim 7 , further comprising: ending power transfer to the Power Receiver; and transitioning to a connected phase in response to detecting the misalignment condition or after the misalignment condition persists for a threshold time.
10. 10 . The method of claim 7 , wherein detecting the misalignment condition includes: verifying that no power transmission faults have been indicated or identified by the Power Receiver or Power Receiver that would cause the Power Transmitter to operate above the PTx limit or prevent the Power Transmitter from satisfying the Guaranteed Power at the PTx limit; and detecting the misalignment condition when a coupling factor (k-factor) is outside a threshold range and no power transmission faults have been indicated or identified.
11. 11 . The method of claim 1 , further comprising: receiving a communication message from the Power Receiver, the communication message including a status field indicating status of the Power Receiver, wherein the status field includes at least one indicator selected from a group consisting of: an indication whether the Power Receiver has wired power available or not; an indication of whether a protective switch is open or closed; and an indication of fault status.
12. 12 . The method of claim 11 , wherein the communication message is a measurement (MEAS) message or a request (RQST) message, and wherein the status field is included in the MEAS or the RQST message.
13. 13 . The method of claim 1 , further comprising: adjusting, during the power transfer phase, a communication carrier level of a communication signal.
14. 14 . The method of claim 13 , further comprising, during the power transfer phase: obtaining a value from the Power Receiver, the value indicating a measured voltage level of the communication signal received by the Power Receiver; and adjusting the communication carrier level based on the value.
15. 15 . The method of claim 13 , further comprising: detecting a change in alignment between a first communication unit of the Power Transmitter and a second communication unit of the Power Receiver; and adjusting the communication carrier level based on the change in alignment.
16. 16 . (canceled)
17. 17 . A method of a Power Receiver (PRx) in a wireless power system, comprising: performing a first power negotiation with a Power Transmitter before a power transfer phase; receiving a suggested negotiation value from the Power Transmitter as part of the first power negotiation, wherein the suggested negotiation value is based on a first Guaranteed Power that the Power Transmitter can guarantee to transfer to the Power Receiver or based on an Available Power of the Power Transmitter; communicating a Requested Power negotiation value to the Power Transmitter, wherein the Requested Power negotiation value is based on the suggested negotiation value; and receiving an indication that the Power Transmitter accepts the Requested Power negotiation value.
18. 18 . (canceled)
19. 19 . The method of claim 17 , further comprising: communicating a negotiation value request message to the Power Transmitter; and receiving the suggested negotiation value from the Power Transmitter in response to the negotiation value request message, wherein the suggested negotiation value is based on a Guaranteed Power that the Power Transmitter can guarantee to transfer to the Power Receiver or based on an Available Power of the Power Transmitter.
20. 20 . The method of claim 17 , further comprising: receiving power from the Power Transmitter during the power transfer phase after the first power negotiation; communicating a power control message to the Power Transmitter, the power control message indicating a requested power level; receiving a message from the Power Transmitter initiating a second power negotiation to establish a second Guaranteed Power to replace the first Guaranteed Power; and receiving a new suggested power negotiation value from the Power Transmitter as part of the second power negotiation.

Description

TECHNICAL FIELD This disclosure relates generally to wireless power. Some aspects of this application relate communication for power negotiation, power control, and fault handling in a wireless power system. DESCRIPTION OF RELATED TECHNOLOGY A wireless power system may include a Power Transmitter and a Power Receiver. For example, the Power Transmitter may be installed on or included in a countertop or other flat surface. The Power Receiver may be included in a cordless appliance, such as a blender, a kettle, an air fryer, a mixer, or a toaster, among other examples. The Power Transmitter may include a primary coil that produces an electromagnetic field that may induce a voltage in a secondary coil of the Power Receiver when the secondary coil is placed in proximity to the primary coil. In this configuration, the electromagnetic field may wirelessly transfer power to the secondary coil. The power may be transferred using inductive coupling or resonant coupling between the primary coil and the secondary coil. The Power Receiver may provide the received power to operate the cordless appliance. SUMMARY The systems, methods, and apparatuses of this disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein. In one innovative aspect, a method may include setting a PTx minimum supported power level of the Power Transmitter, where the PTx minimum supported power level is based on a measurement and processing capability of the Power Transmitter. In one innovative aspect, the subject matter described in this disclosure can be implemented as a method. The method may include transferring power from the Power Transmitter to a Power Receiver during a power transfer phase after a first power negotiation. Method may also include receiving a power control message from the Power Receiver. Method may furthermore include determining that the power control message indicates a requested power level that would cause the Power Transmitter to exceed a current or power limit of the Power Transmitter or that the Power Transmitter cannot satisfy a Guaranteed Power established in the first power negotiation. Method may in addition include transitioning from the power transfer phase to a connected phase. In one innovative aspect, the subject matter described in this disclosure can be implemented as a method. The method may include performing a power negotiation with a Power Receiver during a connected phase. Method may also include receiving a negotiation value request message from the Power Receiver. Method may furthermore include communicating a suggested negotiation value to the Power Receiver in response to the negotiation value request message. In one innovative aspect, the subject matter described in this disclosure can be implemented as a method. The method may include obtaining a communication message from a Power Receiver, where the communication message includes a status field indicating status of the Power Receiver. In one innovative aspect, the subject matter described in this disclosure can be implemented as a method. The method may include transferring power to a Power Receiver during a power transfer phase. Method may also include detecting a misalignment condition causing the Power Transmitter to operate above a PTx limit or preventing the Power Transmitter from satisfying a Guaranteed Power at the PTx limit. In one innovative aspect, the subject matter described in this disclosure can be implemented as a method. The method may include adjusting, during a power transfer phase with a Power Receiver, a communication carrier level of a communication signal. In one innovative aspect, the subject matter described in this disclosure can be implemented as a method. The method may include communicating a power control message to a Power Transmitter during a power transfer phase, where the power control message indicates a requested power level. Method may also include determining that the Power Transmitter has transitioned from the power transfer phase to a connected phase due to the requested power level being less than the PTx minimum supported power level. In one innovative aspect, the subject matter described in this disclosure can be implemented as a method. The method may include receiving power from a Power Transmitter during a power transfer phase after a first power negotiation. Method may also include communicating a power control message to the Power Transmitter. Method may furthermore include receiving a phase transition message from the Power Transmitter indicative that a requested power level that would cause the Power Transmitter to exceed a current or power limit of the Power Transmitter or that the Power Transmitter cannot satisfy a Guaranteed Power established in the first power negotiation. Method may in addition include transitioning from the power transfer phase to a connected phase. In one innovative aspect, the subject matter