Wireless Power Transmitter Magnetic Field Uniformity Testing

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Solution Overview

Problem

There is a need for improved methods and apparatus to test wireless power transmitters and systems effectively, as existing methods are impractical for testing with multiple wireless power receivers and measuring magnetic field uniformity across large areas.

Innovation Solution

A method and system for testing wireless power transmitters involve generating a magnetic field and measuring its uniformity at multiple locations on a charging surface, using a measurement device and processor to determine if the magnetic field values are within a predetermined range, ensuring uniformity and efficient power transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If magnetic field measurements are taken at multiple locations to ensure uniformity, then measurement precision is improved, but testing time and complexity increase

Engineering Contradiction:
Improvemagnetic field uniformity measurementVSAvoidtesting time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The charging surface is divided into multiple discrete measurement locations, allowing systematic coverage of the entire area. By segmenting the measurement task into specific points (e.g., center, corners, edges), the system achieves comprehensive uniformity assessment without requiring continuous scanning, thus balancing precision with testing efficiency

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent establishes predetermined range values for magnetic field measurements at various locations before actual testing. These pre-defined acceptance criteria allow for rapid comparison against measured values, eliminating the need for complex real-time analysis and significantly reducing testing time while maintaining measurement precision

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If magnetic field uniformity is measured across large charging surfaces, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvemagnetic field uniformity measurementVSAvoidtesting system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

A measurement device serves as an intermediary between the wireless power transmitter and the analysis system. This intermediary captures magnetic field data at multiple locations and transmits it to a processor, simplifying the overall system architecture by centralizing the measurement function and reducing the complexity burden on both the transmitter and analysis components

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces complex mechanical scanning systems with a stationary measurement device that takes discrete readings at predetermined locations. This substitution eliminates the need for mechanical movement and positioning systems, significantly reducing device complexity while maintaining the ability to measure magnetic field uniformity across large surfaces

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

3Reliability

If multiple measurements are taken to determine magnetic field uniformity, then reliability is improved, but productivity decreases

Engineering Contradiction:
Improvetesting reliabilityVSAvoidtesting efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent measures magnetic field values at a sufficient number of locations to ensure reliability without requiring exhaustive measurement of every possible point. By selecting key representative locations (center, corners, edges) and comparing against predetermined ranges, the system achieves reliable uniformity assessment with minimal measurements, thus maintaining productivity

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The system incorporates feedback by comparing measured magnetic field values against predetermined range values at each location. This immediate feedback mechanism allows for rapid determination of uniformity compliance without requiring complex post-processing or additional measurements, thereby maintaining high testing efficiency while ensuring reliable results

Inventive Principle:
Principle #23Feedback

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 allows for efficient testing of wireless power transmitters, ensuring uniform magnetic field distribution and effective power transfer to various receivers, simplifying the process and improving testing efficiency.

Implementation Method 1

a transmit antenna configured to generate a magnetic field

Methodology Applied
Scientific EffectElectromagnetic Induction: Electromagnetic Induction

Data Source

PatentEP3204780B1Methods and apparatus for testing of wireless power transmitters and systems
Publication Date: 2018.05.23 QUALCOMM INC
  • EP3204780B1 patent drawingFigure 1~2
  • EP3204780B1 patent drawingFigure 3
  • EP3204780B1 patent drawingFigure 4

AI summary

This disclosure provides methods and apparatus for wireless power field testing. A method for generating testing the interoperability of a wireless power transmitter with one or more wireless power receivers is provided. The method includes generating a magnetic field via a transmit antenna. The method further includes measuring a first uniformity of the magnetic field at all the locations within the magnetic field on a charging surface of the wireless power transmitter. The method also includes determining that the measure first uniformity of the magnetic field is within a range of values at all locations on the charging surface of the wireless power transmitter. In some implementations, the method further includes applying a load to the magnetic field, measuring a second uniformity of the magnetic field while the load is applied, and determining if the first uniformity of the magnetic field is substantially similar to the second uniformity.