Wireless Power Supply Phase Matching Circuit

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Solution Overview

Problem

Existing wireless power supply devices face efficiency reductions due to changes in resonant frequency caused by temporal changes and environmental factors, leading to increased size and complexity of the resonance circuit when adjusting for these changes.

Innovation Solution

A wireless power supply system with a switch controller that adjusts the direction of current flow in the power supply coil to match the phase of the drive signal with the resonance capacitor voltage, using a microcomputer to control semiconductor switches and prevent short circuits, allowing for efficient power transmission without the need for multiple capacitors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple capacitors are connected to the power transmission coil to adjust resonant frequency changes, then the resonant frequency can be maintained, but the circuit size and structural complexity increase

Engineering Contradiction:
Improvepower transmission efficiencyVSAvoidresonance circuit structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the capacitor connection configuration adjustable rather than fixed. The switch element dynamically connects or disconnects the second end of the capacitor from the first end of the power transmission coil based on detected phase differences, allowing the resonance circuit to adapt to frequency changes without adding multiple permanent capacitors.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the electrical parameters of the existing resonance circuit by controlling the switch element to alter the connection state of the capacitor. By changing the connection configuration dynamically, the resonant frequency can be adjusted to compensate for environmental changes without modifying the physical composition of the circuit with additional capacitors.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the resonant frequency is adjusted to match environmental changes, then power transmission efficiency is maintained, but additional capacitors and switches are required

Engineering Contradiction:
Improvepower transmission efficiencyVSAvoidnumber of capacitors
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent makes the capacitor connection dynamic through a switch element controlled by phase difference detection. Instead of providing multiple fixed capacitors, the system dynamically adjusts the connection state of the existing capacitor to achieve frequency matching, thereby maintaining efficiency without increasing the quantity of capacitors.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The resonance circuit performs self-adjustment through the control unit that detects phase differences and automatically controls the switch element to maintain optimal resonant frequency. The system serves itself by using its own existing components (the single capacitor and switch) to compensate for environmental changes without requiring external additions.

Inventive Principle:
Principle #25Self-service

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 solution maintains efficient power transmission by matching the resonant frequency of the power supply device with the receiver, reducing the need for additional capacitors and simplifying the circuit structure, thereby preventing efficiency losses and size/complexity increases.

Implementation Method 1

a power supply coil 12a and a resonance capacitor 12b that are connected in series to each other through a switch element 14b

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a wireless power supply system 100 that wirelessly supplies and receives power by a magnetic field resonance method

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP2999080B1Wireless power supply device
Publication Date: 2019.11.20 FUNAI ELECTRIC CO LTD
  • EP2999080B1 patent drawingFigure 1
  • EP2999080B1 patent drawingFigure 2
  • EP2999080B1 patent drawingFigure 3

AI summary

A wireless power supply device (100) includes a resonance circuit (12) including a coil (12a) and a capacitor (12b), a power supply portion (11) that supplies AC power to the resonance circuit based on a drive signal (S1) having a prescribed drive frequency, and a controller (15) that matches the phase of the drive signal and the phase of oscillation of the resonance circuit by switching the direction of a current that flows into the coil.