Non-Contact Power Transmission Frequency Tuning

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Solution Overview

Problem

Existing power transmission systems face challenges in rapidly tuning frequencies due to interference between control processes for tuning transmission power frequency and resonance frequency, leading to inefficiencies in non-contact power transmission.

Innovation Solution

A power transmitting device and system that utilize two tuners and a controller to discretely tune transmission power frequency and resonance frequency, with the controller optimizing the number of tunings to minimize interference and enable rapid frequency adjustment, employing an inverter for transmission power frequency tuning and a capacitor for resonance frequency tuning, and incorporating a position detector for initial capacitance setting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single high-frequency power driver is used to tune both transmission power frequency and resonance frequency, then device complexity is reduced, but frequency tuning speed deteriorates due to control interference

Engineering Contradiction:
Improvenumber of tunersVSAvoidfrequency tuning speed
Core Design Contradiction:
Device complexityVSSpeed

Solution Approach 1:

The patent divides the frequency tuning function into two separate tuners: a first tuner for transmission power frequency and a second tuner for resonance frequency. This segmentation eliminates control interference between the two tuning processes, allowing each tuner to operate independently and rapidly without conflicting with the other, thereby solving the contradiction between device simplicity and tuning speed.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If discrete tuning steps are used for frequency adjustment, then control precision is improved, but tuning time increases due to multiple adjustment steps

Engineering Contradiction:
Improvefrequency tuning precisionVSAvoidfrequency tuning time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent implements a two-stage tuning process where the second tuner (resonance frequency) performs preliminary coarse adjustment first, establishing a foundation frequency. Then the first tuner (transmission power frequency) performs fine discrete adjustments based on the pre-established resonance frequency. This preliminary action reduces the total number of discrete steps needed, thereby reducing tuning time while maintaining precision.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent employs periodic alternating tuning between the two tuners, where the second tuner adjusts resonance frequency in periodic coarse steps, and the first tuner adjusts transmission power frequency in periodic fine steps. This periodic action pattern allows the system to efficiently progress through frequency adjustments without unnecessary waiting time, balancing precision requirements with time efficiency.

Inventive Principle:
Principle #19Periodic action

3Productivity

If both transmission power frequency and resonance frequency are tuned simultaneously, then overall frequency optimization is achieved, but control stability deteriorates due to mutual interference

Engineering Contradiction:
Improvefrequency optimization efficiencyVSAvoidcontrol stability
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The patent segments the simultaneous tuning process into two independent sequential processes: one for transmission power frequency and another for resonance frequency. By controlling the first tuner and second tuner separately with independent control loops, the system achieves frequency optimization without the control instability that would result from simultaneous adjustment attempts. Each tuner operates with its own stable control parameters.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary resonance frequency tuning using the second tuner before executing transmission power frequency tuning with the first tuner. This preliminary action establishes a stable foundation frequency that reduces the complexity and improves stability of the subsequent transmission power frequency tuning process, allowing both frequencies to be optimized without mutual interference.

Inventive Principle:
Principle #10Preliminary 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 configuration suppresses frequency control interference, allowing for rapid and accurate tuning of transmission power frequency, enhancing power transmission efficiency and reducing the time required for frequency tuning.

Implementation Method 1

a first tuner configured to discretely tune a transmission power frequency

Methodology Applied
Scientific EffectFrequency conversion:

Implementation Method 2

a second tuner configured to discretely tune a resonance frequency of the power transmitting unit

Methodology Applied
Scientific EffectResonance: Resonance

Implementation Method 3

a power transmitting unit configured to transmit AC transmission power to a power receiving device in a non-contact manner

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3351423B1Power transmitting device and power transmission system
Publication Date: 2021.09.22 TOYOTA JIDOSHA KK
  • EP3351423B1 patent drawingFigure 1
  • EP3351423B1 patent drawingFigure 2
  • EP3351423B1 patent drawingFigure 3

AI summary

A power transmitting unit (240) transmits AC transmission power to a power receiving unit (310) in a non-contact manner. An inverter (220) is configured to tune a transmission power frequency at a first frequency interval. A filter circuit (230) includes a capacitor and is configured to tune a resonance frequency of the power transmitting unit (240) at a second frequency interval which is larger than the first frequency interval. A power supply ECU (250) controls the inverter (220) and the capacitor such that the number of tunings of the transmission power frequency using the inverter (220) is larger than the number of tunings of the resonance frequency using the capacitor.