Auxiliary Circuits for Multi-Frequency Wireless Power Transfer

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Solution Overview

Problem

Current multi-frequency wireless power transfer systems face limitations in controlling power transfer rates at different frequencies, leading to cross interference and reduced efficiency due to high quality factors and the need for widely separated frequencies, which increases costs and technical constraints.

Innovation Solution

Incorporating auxiliary circuits with band-pass and/or band-stop filters into receiver and relay circuits to selectively enhance power transfer to targeted loads while minimizing cross interference, allowing non-targeted receivers to act as relay resonators and utilize indirect power paths.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multi-frequency wireless power transfer is implemented without auxiliary filtering circuits, then power transfer rate is enhanced, but cross interference between non-targeted receivers increases

Engineering Contradiction:
Improvepower transfer rateVSAvoidcross interference
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

Band-pass and band-stop filtering circuits are introduced as intermediary elements in the receiver circuits to selectively pass or block specific frequency components. These filtering circuits act as mediators that allow the multi-frequency power transfer to proceed while preventing cross interference between differently tuned receivers, thus resolving the contradiction between enhanced power transfer and reduced interference.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If widely separated frequencies are used for multi-frequency power transfer, then cross interference is reduced, but technical and cost constraints on transmitter and coil resonator design increase

Engineering Contradiction:
Improvecross interferenceVSAvoidtransmitter and coil resonator design constraints
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

Filtering circuits are introduced as intermediary elements that enable the use of closely spaced frequencies by selectively passing or blocking specific frequency components. This eliminates the need for widely separated frequencies, thereby reducing technical and cost constraints on transmitter and resonator design while still preventing cross interference.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the frequency selection parameters by allowing closely spaced frequencies to be used instead of widely separated ones. The filtering circuits enable this parameter change by providing frequency selectivity, thus allowing the system to operate with more flexible and less constrained frequency choices.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If high quality factors are used in resonators to reduce cross interference, then power transfer efficiency improves, but system cost increases

Engineering Contradiction:
Improvecross interferenceVSAvoidsystem cost
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

Filtering circuits are introduced as cost-effective intermediary elements that provide frequency selectivity without requiring extremely high quality factor resonators. These filtering circuits achieve cross interference reduction through selective frequency passing and blocking, thereby reducing system cost while maintaining power transfer efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of operation

If independent control of power transfer rates at different frequencies is required, then selective power transfer to targeted receivers is achieved, but system complexity increases

Engineering Contradiction:
Improveindependent power transfer controlVSAvoidsystem complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The power transfer control is segmented into frequency-specific channels with dedicated filtering circuits for each receiver. Each receiver circuit includes filtering elements that are tuned to specific frequencies, enabling independent control of power transfer rates at different frequencies. This segmentation approach achieves selective control while keeping each control channel relatively simple.

Inventive Principle:
Principle #1Segmentation

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 simultaneous multi-frequency power transfer to multiple targeted loads with reduced cross interference and improved efficiency, allowing for the use of closer operating frequencies and optimizing power transfer paths, thereby enhancing overall system performance.

Implementation Method 1

wireless power transfer technology has re-emerged as a viable technology for domestic and industrial applications

Methodology Applied
Scientific EffectElectromagnetic Induction: Electromagnetic Induction

Implementation Method 2

multi-resonant tanks are used at the transmitter and receiver to amplify and extract power at multiple frequencies

Methodology Applied
Scientific EffectResonance: Resonance

Implementation Method 3

Incorporating auxiliary circuits with band-pass and/or band-stop filters into receiver and relay circuits to selectively enhance power transfer

Methodology Applied
Scientific EffectFilter (electronic): Filter (electronic)

Data Source

PatentEP3105835B1Auxiliary circuits for selection and enhancement of multi-frequency wireless power transfer to multiple loads
Publication Date: 2019.09.11 THE UNIVERSITY OF HONG KONG
  • EP3105835B1 patent drawingFigure 1~2
  • EP3105835B1 patent drawingFigure 3~4
  • EP3105835B1 patent drawingFigure 5~6D

AI summary

This invention is related to a novel method and apparatus that provides selective and enhanced power flow in wireless power transfer systems with multiple receivers. Auxiliary circuits are introduced in the receiver circuits (and relay circuits if applicable) so as to ensure proper frequency-selective wireless power flow to the appropriate targeted receivers, with the pickup power by the non-targeted receivers substantially reduced even if the chosen tuned frequencies for different receivers are not widely apart.