Wireless Power Transfer Control Using kQ Evaluation Index

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Solution Overview

Problem

Wireless power transfer systems face challenges in efficiently transferring power to multiple receivers without proper evaluation indices, leading to difficulties in determining whether to use time-division or simultaneous power transfer methods, resulting in inappropriate power distribution among receivers.

Innovation Solution

A wireless power transfer control method and system that utilize a kQ value as an evaluation index to determine whether to perform simultaneous or time-division power transfer based on the degree of coupling and loss of electromagnetic fields, allowing for optimal power distribution among multiple receivers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If simultaneous power transfer is performed to multiple power receivers, then power distribution efficiency is improved, but it becomes difficult to determine appropriate power allocation without evaluation indices

Engineering Contradiction:

Improvepower distribution efficiencyVSAvoidcontrol complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent introduces a kQ value as a quantitative evaluation parameter to characterize the coupling strength between power transmission and reception devices. By calculating and comparing kQ values, the system can objectively determine power allocation strategies, transforming the complex control problem into a parameter-based decision process that balances efficiency and manageability

Inventive Principle:

Principle #35Parameter changes

2Ease of operation

If time-division power transfer is used for multiple power receivers, then control simplicity is improved, but overall power transfer efficiency deteriorates due to sequential transmission

Engineering Contradiction:

Improvecontrol simplicityVSAvoidpower transfer efficiency

Core Design Contradiction:

Ease of operationVSProductivity

Solution Approach 1:

The patent enables dynamic switching between time-division and simultaneous power transfer modes based on real-time kQ value evaluations. The system adapts its operational mode according to the coupling characteristics of different receiver pairs, optimizing efficiency without requiring complex manual control configurations

Inventive Principle:

Principle #15Dynamics

3Adaptability or versatility

If wireless power transfer is performed to multiple power receivers, then system versatility is improved, but determining appropriate power distribution becomes difficult without evaluation indices

Engineering Contradiction:

Improvesystem versatilityVSAvoidlack of evaluation criteria

Core Design Contradiction:

Adaptability or versatilityVSLoss of information

Solution Approach 1:

The patent implements a feedback mechanism where the master power transmission device calculates kQ values based on communication information from power receivers, evaluates coupling strengths, and adjusts power distribution accordingly. This closed-loop approach provides the missing evaluation criteria, enabling versatile multi-receiver operation with intelligent power allocation

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

Enables appropriate wireless power transfer by switching between time-division and simultaneous power transfer methods, ensuring efficient power distribution and maintaining system efficiency across various power requirements and receiver configurations.

Implementation Method 1

CA2868101 discloses a wireless power transmission system comprising a plurality of power transmission devices and at least one power receiving device and performs wireless power transmission from the power transmission device to the power receiving device by using magnetic field resonance or electric field resonance

Methodology Applied

Scientific EffectMagnetic field resonance: Resonance

Implementation Method 2

Methodology Applied

Scientific EffectElectric field resonance: Resonance

Implementation Method 3

Conventionally, techniques using electromagnetic induction, and techniques using radio waves are generally known as wireless power transfer techniques

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3151377B1Wireless power transmission control method and wireless power transmission system

Publication Date: 2019.07.31 FUJITSU LTD

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Figure 2A~2B
Figure 3

AI summary

A wireless power transfer control method for a system including at least one power source and at least two power receivers, wirelessly transfers power from the power source to each of the power receivers using one of magnetic field resonance and electric field resonance, including a simultaneous power transfer mode in which power is simultaneously transferred to the power receivers; and a time-division power transfer mode in which power is sequentially transferred to the power receivers by time-division switching. The wireless power transfer control method includes setting an evaluation index for each of the power receivers; and performing wireless power transfer by switching between the simultaneous power transfer mode and the time-division power transfer mode, on the basis of the evaluation index.