Wireless Power Control via Harmonic Feedback

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Solution Overview

Problem

Existing wireless power transfer systems face challenges in efficiently and safely charging devices, particularly medical implants, due to the need for physical connections and varying power requirements, which can be inconvenient and aesthetically displeasing, and lack effective feedback mechanisms for ensuring correct power delivery.

Innovation Solution

A wireless power transfer system that includes a transmitter and receiver configured for mutual resonant relationships, using harmonics detection to adjust the power level of the wireless field based on detected second and third harmonics, allowing for closed-loop power control and ensuring the correct voltage is delivered to the device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If wireless power transfer is used to eliminate physical connections, then convenience and aesthetics are improved, but power delivery control and safety become more difficult

Engineering Contradiction:
ImproveconvenienceVSAvoidpower delivery control
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system employs a feedback mechanism where the receiver detects harmonics in the transmitted power signal and communicates power level information back to the transmitter. The transmitter monitors this feedback and adjusts its power output accordingly, enabling closed-loop control that ensures safe and accurate power delivery without physical connections.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system changes the parameter being monitored from direct power measurement to harmonic detection. By detecting the presence and strength of harmonics in the power signal, the system indirectly measures power delivery status and uses this information to control transmitter output, solving the control problem in wireless power transfer.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If harmonic detection is used to control power levels, then power delivery accuracy is improved, but system complexity increases

Engineering Contradiction:
Improvepower delivery accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system introduces harmonics as an intermediary signal that carries power level information. Instead of directly measuring complex power parameters, the system uses harmonic detection as a simplified intermediary mechanism. The harmonics serve as a natural byproduct of the power transfer process that encodes useful control information, reducing measurement complexity while maintaining accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If incremental power increase is used to detect receiver presence, then safety is improved, but charging time increases

Engineering Contradiction:
ImprovesafetyVSAvoidcharging time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary detection of the receiver's presence and proper coupling before initiating full power transfer. By using incremental power increases with harmonic detection at each stage, the system ensures the receiver is correctly positioned and ready to receive power, preventing unsafe operation while minimizing overall charging time through efficient staged power delivery.

Inventive Principle:
Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This system enables efficient and safe wireless power transfer over varying distances and through different materials, ensuring devices receive the correct power supply without the need for physical connections, and allows for effective feedback mechanisms to adjust power levels, enhancing convenience and safety.

Implementation Method 1

generating a wireless field for wireless power transfer

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

detecting levels of second harmonics and third harmonics of the generated wireless field

Methodology Applied
Scientific EffectHarmonics detection:

Data Source

PatentEP3501081B1Wirless power transfer control
Publication Date: 2020.09.23 QUALCOMM INC
  • EP3501081B1 patent drawingFigure 1~3
  • EP3501081B1 patent drawingFigure 4
  • EP3501081B1 patent drawingFigure 5

AI summary

Certain aspects of the present disclosure relate to methods and apparatus for controlling a power level of wireless power transfer. Certain aspects provide a wireless power receiver. The wireless power receiver includes an antenna and a rectifier. The rectifier includes a first diode and a second diode. The wireless power receiver further includes a resistor in parallel with the first diode. A first terminal of the resistor is coupled to a first terminal of the first diode. A second terminal of the resistor is coupled to a second terminal of the first diode.