Wireless Power Transfer Layout With Local DC/AC Converters

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Solution Overview

Problem

As the number of power transmission units increases in a wireless power transfer system, the difference in wire lengths between units closer and farther from the high-frequency power source increases, leading to variations in parasitic components and power transfer efficiency.

Innovation Solution

A wireless power transfer apparatus is configured with a DC power supply unit and multiple DC/AC converters, where the rated power of the DC power supply is greater than that of the DC/AC converters, allowing for separate wiring regions for DC and AC connections, minimizing the distance between converters and power transmission devices, and reducing variations in power transfer efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If multiple power transmission units are connected in parallel to a high-frequency power source through switches, then the power supply capacity is increased, but the difference in wire lengths between units closer and farther from the power source increases, leading to variations in parasitic inductances and power transfer efficiency

Engineering Contradiction:
Improvepower supply capacityVSAvoidpower transfer efficiency consistency
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The system segments the power distribution into two stages: first, DC power is distributed to multiple DC/AC converters through DC wirings; second, each DC/AC converter generates AC power locally and supplies it to power transmission devices through short AC wirings. This segmentation ensures that each power transmission device has its own dedicated AC power source, eliminating the wire length difference problem that would occur if all devices were connected directly to a single high-frequency power source.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If all power transmission devices are connected to a single DC/AC converter through AC wirings, then the device complexity is reduced, but the AC wiring length increases, leading to greater AC losses and impedance variations

Engineering Contradiction:
Improvewiring structure simplicityVSAvoidAC losses
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The system divides the power conversion function across multiple DC/AC converters, each serving a local group of power transmission devices. This creates shorter AC wiring paths from each converter to its associated devices, reducing AC losses and impedance variations compared to a single centralized converter that would require long AC wirings to reach all devices.

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 configuration reduces installation costs and AC losses while maintaining consistent power transfer efficiency across multiple power transmission devices by keeping AC wiring lengths short and minimizing impedance differences.

Implementation Method 1

at least one DC/AC converter connected to the at least one DC wiring

Methodology Applied
Scientific EffectPower conversion (DC to AC):

Data Source

PatentEP4704305A1Non-contact power supply device
Publication Date: 2026.03.04 DENSO CORP
  • EP4704305A1 patent drawingFigure 1
  • EP4704305A1 patent drawingFigure 2
  • EP4704305A1 patent drawingFigure 3

AI summary

A wireless power transfer system (10) for wireless power transfer to a power reception device (80) includes a DC power supply unit (20), at least one DC wiring (51) through which output power of the DC power supply unit is transferred, at least one DC/AC converter (30) connected to the at least one DC wiring, at least one AC wiring (52) through which output power of the at least one DC/AC converter is transferred, and at least one power transmission device (40) connected to the at least one AC wiring. A rated power of the DC power supply is greater than that of the at least one DC/AC converter.