Bus End Arc Interrupter Using Electromagnetic Guidance

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Solution Overview

Problem

Existing methods for controlling arcing in electrical distribution equipment, such as between busbars or a busbar and ground, fail to effectively limit the duration and damage caused by arcs, leading to potential equipment damage and personnel harm due to arc flash and arc blast.

Innovation Solution

An arc interruption device is designed to utilize electromagnetic forces to guide arcs into an enclosure where they are stretched and lengthened through specific geometries, including a phase barrier and C-shaped channels, ultimately extinguishing the arc by increasing voltage and reducing current.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If passive arc control techniques (containment and directed venting) are used, then arc blast energy and gasses are contained and vented, but the duration of the arcing event is not limited

Engineering Contradiction:
Improvearc blast damageVSAvoidarcing duration
Core Design Contradiction:
Object-affected harmful factorsVSDuration of action of moving object

Solution Approach 1:

The patent utilizes the electromagnetic forces generated by the arc itself to push the arc toward the terminal ends of the conductors and into the arc interrupter enclosure. This converts the harmful arc energy into a beneficial self-directed force that guides the arc into the interruption zone without requiring external active control systems.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The arc interrupter enclosure acts as an intermediary structure that receives the arc at its entrance and guides it through a shaped path to the exhaust port. The enclosure provides a controlled environment where the arc can be stretched and lengthened, ultimately extinguishing it before it can cause extensive damage.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If active arc control techniques with sensing and switching mechanisms are used, then arc current can be controlled, but cost increases and nuisance breaker trips may occur

Engineering Contradiction:
Improvearc control effectivenessVSAvoidsensing and switching mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system is designed to be self-actuating, using the inherent electromagnetic forces of the arc to drive it into the interrupter enclosure. No external sensors, controllers, or switching mechanisms are required - the arc's own energy propels it into the extinction zone, eliminating complex control systems.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent extracts only the essential function needed for arc control - the passive enclosure with shaped internal geometry - while removing all unnecessary active control components. This simplifies the system to its core effective elements without sensing or switching mechanisms.

Inventive Principle:
Principle #2Taking out (Extraction)

3Temperature

If the enclosure geometry stretches and lengthens the arc, then arc current and temperature are attenuated, but the enclosure structure becomes more complex

Engineering Contradiction:
Improvearc temperatureVSAvoidenclosure geometry complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The enclosure incorporates curved and shaped internal geometries, including C-shaped channel members and a convergence device resembling a cone, that guide and stretch the arc through a serpentine path. These curved paths lengthen the arc and attenuate its temperature without requiring complex mechanical components.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The arc is forced to travel through a three-dimensional shaped path within the enclosure rather than a straight line. The C-shaped corridors and convergence device create a volumetric extinction zone that stretches the arc in multiple directions, increasing its length and reducing its temperature through spatial manipulation.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 solution effectively limits the duration and energy of arcs, preventing them from causing damage by forcing the arc to be sustained and extinguished within the device, thereby reducing the risk of arc flash and arc blast.

Implementation Method 1

The embodiments disclosed herein are directed to methods and systems for controlling and limiting the damage caused by arcs formed on exposed conductors... The methods and systems take advantage of the tendency for electromagnetic forces to push an arc in a direction away from a current source.

Methodology Applied
Scientific EffectElectromagnetic forces: Lorentz Force

Implementation Method 2

Inside the arc interrupter, the shape of the arc is conformed to geometries designed to stretch and lengthen the arc, and thereby attenuate its current and temperature to the point where it can no longer be sustained and is ultimately extinguished.

Methodology Applied
Scientific EffectArc stretching: Electric Arc

Data Source

PatentEP3041014B1Bus end arc interrupter
Publication Date: 2018.08.01 SCHNEIDER ELECTRIC USA INC
  • EP3041014B1 patent drawingFigure 1
  • EP3041014B1 patent drawingFigure 2
  • EP3041014B1 patent drawingFigure 3A~3B

AI summary

Method and system for controlling and limiting the damage caused by arcs formed on exposed conductors in electrical distribution equipment involve using the tendency of an arc to move in a direction away from a current source and toward the terminal ends of the conductors. An arc interruption device, or arc interrupter, is placed over the terminal ends of the conductor to capture the arc as it travels toward the terminal ends of the conductors. Within the arc interrupter, the shape of the arc is conformed to geometries designed to stretch and extend the arc to the point where it can no longer be sustained and is extinguished.