Diverging Electrode Layer Structure Arc Mobility

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Solution Overview

Problem

Existing lightning protection spark routes with divergent electrodes face challenges in managing high impulse power loads and electromagnetic forces, leading to undesirable thermal overload and destruction of the spark route due to the high power forces acting on the arc.

Innovation Solution

The use of divergent electrodes with a layer structure of different conductive layers, where the conductive layers consist of materials with significantly different electrical conductivity (factor > 4 or > 10), with the higher conductivity layer in the running area of the electrodes, enhances the arc mobility and reduces forces at high impulse current loads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If homogeneous conductive material is used for electrodes, then manufacturing is simple, but arc mobility is insufficient and thermal overload occurs

Engineering Contradiction:
Improvearc mobilityVSAvoidelectrode structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The electrode is constructed as a composite structure with a base material (e.g., stainless steel) and an applied conductive layer (e.g., copper or silver). This composite structure combines the mechanical strength of the base material with the high electrical conductivity of the conductive layer, enabling improved arc mobility while maintaining structural integrity under impulse current loads.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The conductive layer is applied selectively to specific regions of the electrode, particularly to the running area where arc movement occurs. This localized application optimizes arc mobility in the critical region while maintaining the overall structural properties of the electrode, avoiding unnecessary complexity in non-critical areas.

Inventive Principle:
Principle #3Local quality

2Speed

If conductive layer is applied to increase arc mobility, then arc enters quenching chamber faster, but forces on arc increase quadratically with current height

Engineering Contradiction:
Improvearc propagation speedVSAvoidelectromagnetic force on arc
Core Design Contradiction:
SpeedVSForce

Solution Approach 1:

The electrode design changes the electrical conductivity parameter through the applied conductive layer, which modifies the current distribution and reduces the intrinsic magnetic field strength. This parameter change allows for faster arc propagation while limiting the electromagnetic forces acting on the arc, preventing quadratic force increase with current height.

Inventive Principle:
Principle #35Parameter changes

3Power

If high conductivity material is used, then arc voltage is minimized during pulse current, but thermal overload destroys the spark gap

Engineering Contradiction:
Improvearc power outputVSAvoidspark gap durability
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The composite electrode structure with base material and conductive layer provides both low arc voltage during pulse current (through high conductivity) and thermal resistance to protect against thermal overload. The base material acts as a thermal barrier while the conductive layer minimizes arc power, creating a protective effect against destruction.

Inventive Principle:
Principle #40Composite materials

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 increases the running speed of the arc during network successive flow, reduces thermal overload, and minimizes performance turnover, thereby protecting the materials and assembly from damage.

Implementation Method 1

the conductive layer with higher electrical conductivity is provided at least in the running area of one of the diverging electrodes... increases the running speed of the arc during network successive flow... reduces the forces acting on the arc under high pulse current loads

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Data Source

PatentEP3931921B1Lightning-protection spark gap
Publication Date: 2025.04.30 DEHN SOHNE GMBH CO KG
  • EP3931921B1 patent drawingFigure 1~2
  • EP3931921B1 patent drawingFigure 3~4
  • EP3931921B1 patent drawingFigure 5

AI summary

The present invention provides a lightning-protection spark gap with a first diverging electrode (3a), which has a first outer side (Aa) and a first inner side (Ia), and a second diverging electrode (3b), which has a second outer side (Ab) and a second inner side (Ib), wherein the first and the second diverging electrodes (3a, 3b) are formed from a conductive basic material which has a first electrical conductivity, wherein an ignition region (Z) and an adjoining propagation region (L) for an arc are formed between the first inner side (Ia) of the first diverging electrode (3a) and the second inner side (Ib) of the second diverging electrode (3b), wherein a conductive layer (6a, 6b) composed of a conductive material with a second electrical conductivity is applied to the basic material at least in regions at least in the propagation region (L) of one of the first and the second diverging electrodes (3a, 3b), and wherein the second electrical conductivity is higher than the first electrical conductivity.