Rotating Magnet Inductive Power Transfer Gap Efficiency

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Solution Overview

Problem

Existing inductive power transfer technologies face inefficiencies at low frequencies due to limitations in coupling efficiency between coils, especially when they are not in extreme proximity, and there are concerns about the medical side effects of RF frequencies.

Innovation Solution

The use of a rotating or oscillating permanent magnet to enhance inductive power transfer by increasing the magnitude of the time-varying magnetic field, allowing for efficient power transfer over larger gaps without the need for high permeability materials, which mitigates demagnetization effects and maintains high power transfer efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If coils are placed in extreme proximity to achieve high coupling efficiency, then power transfer efficiency is improved, but device complexity and spatial constraints increase

Engineering Contradiction:

Improvepower transfer efficiencyVSAvoidspatial arrangement complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

A rotating permanent magnet is introduced as an intermediary component between the transmitter and receiver coils. The magnet rotates in response to the transmitter's magnetic field, mechanically coupling the two coils and enabling efficient power transfer over larger gaps without requiring extreme proximity or complex spatial arrangements

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system employs dynamic rotation of the permanent magnet rather than static coil placement. The magnet's rotational motion allows it to continuously interact with both the transmitter and receiver coils, maintaining coupling efficiency while accommodating larger spatial separation and simplifying device geometry

Inventive Principle:

Principle #15Dynamics

2Loss of energy

If RF frequencies are used to achieve high Q resonance, then power transfer efficiency is improved, but potential medical side effects increase

Engineering Contradiction:

Improvepower transfer efficiencyVSAvoidmedical side effects

Core Design Contradiction:

Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The system changes the operating frequency parameter from RF frequencies to lower frequencies (e.g., 60 Hz or other power line frequencies). The rotating magnet mechanism compensates for the lower Q factor at these frequencies by providing mechanical coupling, thus maintaining power transfer efficiency while eliminating the harmful effects associated with RF exposure

Inventive Principle:

Principle #35Parameter changes

3Loss of energy

If high permeability materials are used to enhance magnetic coupling, then power transfer efficiency is improved, but demagnetization effects increase

Engineering Contradiction:

Improvepower transfer efficiencyVSAvoidmagnetic field strength

Core Design Contradiction:

Loss of energyVSStrength

Solution Approach 1:

The rotating permanent magnet serves as an intermediary that transfers magnetic flux between coils without requiring high permeability materials. This approach maintains strong magnetic coupling while avoiding the demagnetization effects that occur when high permeability materials are exposed to strong alternating magnetic fields

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system employs periodic rotation of the permanent magnet synchronized with the transmitter frequency. This periodic action creates consistent magnetic coupling throughout each rotation cycle, maintaining power transfer efficiency without the need for high permeability materials that would be subject to demagnetization

Inventive Principle:

Principle #19Periodic 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 approach significantly increases power transfer efficiency by amplifying the magnetic field in the receiver coil, enabling effective low-frequency power transmission with reduced energy losses and avoiding the potential health risks associated with RF frequencies.

Implementation Method 1

power can be wirelessly conveyed from one place to another using the Faraday effect, whereby a changing magnetic field causes an electrical current to flow in an electrically isolated secondary circuit

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

Methodology Applied

Scientific EffectFaraday effect: Faraday Effect

Data Source

PatentUS9071062B2Systems and methods for dipole enhanced inductive power transfer

Publication Date: 2015.06.30 THE UNIV OF BRITISH COLUMBIA

AI summary

An inductive power transfer apparatus is disclosed. A transmitter generates a first time varying magnetic field. A receiver is separated from the transmitter by a gap, but is located with the first time varying magnetic field. The receiver comprises: a conductor; and a receiver magnet located in the first time varying magnetic field and supported for movement in response to the first time varying magnetic field. The conductor and receiver are positioned relative to one another such that movement of the receiver magnet creates a second time-varying magnetic field in a vicinity of the conductor to thereby induce current in the conductor.