Wireless Power Transmit Characteristic Detection via Series Element Voltage

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Solution Overview

Problem

Existing wireless power transfer systems face inefficiencies in detecting and adjusting transmit characteristics, which can lead to suboptimal power transfer and potential safety issues due to the presence of unintended objects or variations in receiver devices.

Innovation Solution

A method and apparatus that determine real and imaginary components of voltages and currents at series elements in a wireless power transmission device, allowing for the calculation of transmit characteristics and adjustment of power transmission based on these determinations, using a series element coupled to a transmit coil and quadrature clock signals for precise control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If wireless power transmission is performed without detecting transmit characteristics, then power transfer can occur, but efficiency is reduced and safety issues arise due to unintended objects or receiver variations

Engineering Contradiction:
Improvesafety and efficiency of power transferVSAvoidcomplexity of detection system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system measures voltages and currents at the transmit coil terminals, calculates transmit characteristics (impedance, power, efficiency), and uses this feedback to dynamically adjust transmission parameters. This closed-loop feedback mechanism ensures safe and efficient power transfer by detecting the presence and state of receiver devices, resolving the contradiction between safety and system complexity.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces complex physical sensing mechanisms with electrical measurements. By measuring voltages and currents at the transmit coil terminals and calculating transmit characteristics from these electrical parameters, the system achieves detection functionality without requiring additional mechanical or physical sensors, thus improving reliability while minimizing the increase in device complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If transmit characteristics are continuously monitored and adjusted, then power transfer efficiency is optimized, but system complexity and computational requirements increase

Engineering Contradiction:
Improvepower transfer efficiencyVSAvoidcomplexity of control system
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system continuously monitors transmit characteristics by measuring voltages and currents, calculates efficiency metrics, and adjusts transmission parameters in real-time. This feedback-driven optimization maximizes power transfer efficiency while maintaining manageable system complexity through algorithmic control rather than hardware complexity.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system optimizes power transfer efficiency by dynamically changing transmission parameters (such as frequency, power level, or impedance matching) based on calculated transmit characteristics. This approach enables efficient power transfer without requiring complex hardware modifications, as optimization is achieved through parameter adjustment controlled by software or firmware.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If simple voltage and current measurements are used to detect transmit characteristics, then detection is straightforward, but precision and accuracy of characterization are insufficient

Engineering Contradiction:
Improveaccuracy of transmit characteristic detectionVSAvoidcomplexity of measurement process
Core Design Contradiction:
Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent replaces complex physical measurement systems with electrical measurements and computational analysis. By measuring voltages and currents at the transmit coil terminals and using calculations to derive transmit characteristics (impedance, power, efficiency), the system achieves high measurement precision without increasing the physical complexity of the measurement process. The complexity is shifted from hardware to software/algorithms.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 approach enables efficient and safe wireless power transfer by accurately detecting and adapting to the presence of intended receivers and avoiding unintended objects, optimizing power delivery and ensuring compliance with safety regulations.

Implementation Method 1

a transmit coil configured to transmit wireless power to a receiver

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2901564B1Systems and methods for detecting wireless charging transmit characteristics
Publication Date: 2018.09.12 QUALCOMM INC
  • EP2901564B1 patent drawingFigure 1~3
  • EP2901564B1 patent drawingFigure 4~5
  • EP2901564B1 patent drawingFigure 6

AI summary

This disclosure provides systems, methods and apparatus for detecting wireless charging transmit characteristics. One aspect of the disclosure provides a method of detecting a transmit characteristic in a wireless power transmission device. The device includes a series element electrically coupled to a transmit coil. The method includes determining real and imaginary components of a first voltage at a first terminal of the series element. The method further includes determining real and imaginary components of a second voltage at a second terminal of the series element. The method further includes determining real and imaginary components of a current through the series element, based on the determined first and second voltages. The method further includes determining transmit characteristics such as nodal voltages, currents, power and impedances based on determined voltages and currents. The method further includes adjusting a characteristic of a wireless power transmission based on the determined transmit characteristics.