Reconfigurable DC Output Filter Circuit for Wireless Power Transfer

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Solution Overview

Problem

Existing DC output filter circuits in wireless power transfer systems face inefficiencies due to mismatched impedance between the load and the filter circuit, leading to suboptimal current waveform shaping and reduced operational efficiency.

Innovation Solution

A reconfigurable DC output filter circuit that dynamically adjusts its configuration based on operating efficiency curves, switching between capacitive and capacitive-inductive filter configurations to match changing load impedance, thereby reshaping the current waveform and optimizing efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a fixed DC output filter circuit configuration is used, then the circuit structure is simple, but the operational efficiency decreases due to impedance mismatch with varying loads

Engineering Contradiction:
Improveoperational efficiencyVSAvoidfilter circuit configuration
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the DC output filter circuit reconfigurable, allowing it to dynamically switch between different configurations (e.g., capacitor-only, inductor-capacitor combinations) based on load conditions. This dynamic adaptation enables the filter to maintain optimal impedance matching with varying loads, thereby improving operational efficiency while managing circuit complexity through controlled reconfiguration

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by varying the filter circuit configuration parameters (inductance values, capacitance values, and their series/parallel arrangements) according to load requirements. By changing these parameters dynamically, the system optimizes the filter's impedance characteristics to match different load conditions, resolving the contradiction between fixed simplicity and variable efficiency

Inventive Principle:
Principle #35Parameter changes

2Loss of energy

If the filter circuit is reconfigured to match varying load impedance, then operational efficiency improves, but the current waveform shaping becomes more complex

Engineering Contradiction:
Improveoperational efficiencyVSAvoidcurrent waveform shaping
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the filter circuit into modular components (multiple capacitors and inductors) that can be independently switched and reconfigured. This segmentation allows the system to create different filter configurations (C-filter, LC-filter, etc.) by connecting specific segments, thereby achieving efficient current waveform shaping across varying loads without requiring a completely complex redesign for each condition

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If a reconfigurable filter circuit is implemented, then adaptability to varying loads improves, but the control system complexity increases

Engineering Contradiction:
Improveload condition adaptationVSAvoidcontrol system
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements feedback by using a controller that monitors load conditions and automatically adjusts the filter circuit configuration accordingly. The controller receives feedback about the current load state and switches between pre-defined filter configurations (capacitor-only, inductor-capacitor series, inductor-capacitor parallel) to maintain optimal performance, thereby achieving high adaptability while managing control complexity through systematic feedback-based switching

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

The reconfigurable filter circuit enhances operational efficiency by adapting to varying load conditions, improving power delivery and reducing losses in wireless power transfer systems, particularly in AC to DC converter circuits and wireless charging applications.

Implementation Method 1

changing a configuration of a DC output filter circuit to reshape a current waveform in a rectifier circuit

Methodology Applied
Scientific EffectElectrical filtering: Filter (electronic)

Data Source

PatentEP3090480B1Methods, circuits and articles of manufacture for configuring DC output filter circuits
Publication Date: 2021.05.12 EATON CAPITAL
  • EP3090480B1 patent drawingFigure 1~2
  • EP3090480B1 patent drawingFigure 3
  • EP3090480B1 patent drawingFigure 4A~4B

AI summary

A method of operating an AC to DC converter circuit can be provided by changing a configuration of a DC output filter circuit to reshape a current waveform in a rectifier circuit, included in the AC to DC converter circuit, based on an operating efficiency of the AC to DC converter circuit. Related circuits and articles of manufacture are also disclosed.