Plasma Generator Edge Ignition Prevention via Load Detection

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Solution Overview

Problem

Existing plasma generators using piezoelectric transformers for non-thermal atmospheric pressure plasma generation face issues with undesired plasma ignitions at longitudinal edges, which can lead to component damage, and existing solutions like edge rounding or insulation reduce efficiency and lifespan.

Innovation Solution

A plasma generator design where power is only applied to the input region of the piezoelectric transformer when a load is detected in front of the output-side end face, using control electronics to measure operating parameters and apply AC voltage, concentrating the electric field on the load to prevent edge ignitions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If insulation is added to surround the exit area or edges are rounded off to prevent plasma ignition, then reliability is improved, but device complexity increases and productivity decreases

Engineering Contradiction:
Improveprevention of plasma ignitionVSAvoidadditional insulation components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the operating parameters by implementing control electronics that monitor the piezoelectric transformer's operating state (impedance, resonant frequency, phase) and dynamically adjust the power supply to the input area. This allows the system to prevent plasma ignition through parameter control rather than adding physical insulation structures, thereby improving reliability without increasing device complexity

Inventive Principle:
Principle #35Parameter changes

2Reliability

If insulation is added to prevent plasma ignition, then reliability is improved, but manufacturing effort increases

Engineering Contradiction:
Improveprevention of plasma ignitionVSAvoidmanufacturing effort
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces the mechanical/physical approach of adding insulation structures with an electronic control system. The control electronics monitor operating parameters and regulate power delivery to prevent plasma ignition, eliminating the need for additional manufacturing steps such as insulating the exit area or rounding edges, thereby improving reliability while maintaining ease of manufacture

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If power is continuously applied to the input region, then productivity is improved, but harmful factors increase due to plasma ignition at edges

Engineering Contradiction:
Improveplasma generation efficiencyVSAvoidplasma ignition at edges
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent implements a feedback control system where control electronics continuously monitor operating parameters (impedance, resonant frequency, phase between input current and voltage) of the piezoelectric transformer. Based on this feedback, the system dynamically adjusts the power supplied to the input area, enabling continuous operation at high productivity while preventing harmful plasma ignition at edges through real-time parameter regulation

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

This approach effectively prevents plasma ignitions along the longitudinal edges, maintaining efficiency and extending the lifespan of the transformer by ensuring plasma generation only occurs when a load is present, thus eliminating the need for additional insulation or edge modifications.

Implementation Method 1

a piezoelectric transformer, which is a type of resonance transformer which is based on piezoelectricity

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

The at least one operating parameter can be a phase between the input current and the input voltage, an impedance of the transformer, or a resonant frequency of the transformer

Methodology Applied
Scientific EffectImpedance measurement: Electrical Impedance Tomography

Data Source

PatentEP3597015B1Plasma generator
Publication Date: 2021.05.05 TDK ELECTRONICS AG
  • EP3597015B1 patent drawingFigure 1
  • EP3597015B1 patent drawingFigure 2~3
  • EP3597015B1 patent drawingFigure 4~5

AI summary

The present invention relates to a plasma generator for generating non-thermal atmospheric-pressure plasma, comprising a piezoelectric transformer (1), which is divided in the longitudinal direction (L) into an input region (2) and an output region (3), wherein an alternating voltage can be applied to the input region (2), wherein: the output region (3) comprises a piezoelectric material (9) that causes the establishment of an electric field when alternating voltage is applied to the input region (2), the piezoelectric transformer (1) comprises an output-side end face (10) that faces away from the input region (2), and the plasma generator is designed in such a way that a power sufficient to ignite a non-thermal atmospheric-pressure plasma can be applied to the input region (2) of the piezoelectric transformer (1) only when a load (18, 19, 22) is arranged in front of the output-side end face (10).