Insulating Screen for Compact Medium-Voltage Switchboard Contact System

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Solution Overview

Problem

Medium-voltage switchboards face challenges in maintaining compactness while preventing early arc formation between high-voltage contact pieces and encapsulation, which can lead to increased pressure and potential explosion during arcing faults.

Innovation Solution

The implementation of a screen of insulating material between fixed and moving contact pieces, which can be penetrated by the moving contact, designed to prevent early arc formation and allow for a more compact switchboard design, with options for the insulating material to be soft or hinged, and potentially surrounded by a tubular cylinder filled with insulating fluid.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If fixed contact pieces are exposed within the switchboard to enable contact operation, then the switchboard can function properly, but the distance between contact pieces and encapsulation must be increased to prevent arcing, resulting in larger space requirements

Engineering Contradiction:

Improvecontact operation reliabilityVSAvoidswitchboard volume

Core Design Contradiction:

ReliabilityVSVolume of stationary object

Solution Approach 1:

An insulating screen is introduced as an intermediary element between the fixed contact piece and the moving contact piece. This screen prevents early arc formation while allowing the moving contact piece to penetrate it during normal operation. The screen acts as a mediator that enables compact spacing without compromising safety or reliability.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The insulating screen is positioned specifically in the critical region where early arc formation could occur between contact pieces and encapsulation. By providing localized insulation only where needed, the design maintains compact overall dimensions while preventing arcing in the specific high-risk zone.

Inventive Principle:

Principle #3Local quality

2Volume of stationary object

If the distance between contact pieces and encapsulation is reduced to make the switchboard more compact, then space requirements are minimized, but the risk of early arc formation increases

Engineering Contradiction:

Improveswitchboard volumeVSAvoidarc formation risk

Core Design Contradiction:

Volume of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The insulating screen serves as a protective intermediary that allows reduced spacing between contact pieces and encapsulation. It mediates between the need for compact design and the need to prevent arcing, enabling the moving contact piece to approach the fixed contact piece closely without creating harmful early arcs.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The insulating screen provides preliminary protection against arc formation by being positioned in advance in the path where arcs could prematurely form. It prevents the harmful effect of early arcing before it can occur, allowing safer reduced spacing.

Inventive Principle:

Principle #9Preliminary anti-action

3Ease of operation

If the insulating material is made soft to allow easy penetration by the moving contact piece, then ease of operation is improved, but the material may deform or fail to provide sufficient insulation

Engineering Contradiction:

Improvecontact piece penetrationVSAvoidinsulation reliability

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The insulating screen exhibits different mechanical properties in different regions: the portion in the movement path of the moving contact piece is made soft for easy penetration, while other portions maintain greater rigidity to provide sufficient insulation. This local differentiation of material properties resolves the contradiction between ease of operation and insulation reliability.

Inventive Principle:

Principle #3Local quality

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 enables a more compact switchboard with reduced space requirements while effectively suppressing arc formation during arcing faults, ensuring safety by minimizing the risk of explosion and allowing controlled gas release.

Implementation Method 1

at least one fixed contact piece being assigned a screen of insulating material, which can be penetrated by the moving contact piece to make contact with the fixed contact piece

Methodology Applied

Scientific EffectElectrical insulation: Dielectric

Implementation Method 2

the screen being arranged between the fixed and moving contact piece... the moving contact piece can penetrate the material

Methodology Applied

Scientific EffectMechanical penetration: Impact Force

Data Source

PatentUS7935907B2Contact system for a short-circuiting device in a medium-voltage or high-voltage switchboard plant

Publication Date: 2011.05.03 ABB (SCHWEIZ) AG

AI summary

A contact system for a short-circuiting device for a switchboard, the contact system including at least one fixed contact piece connected to a main voltage source. The contact system also includes at least one moving contact piece and an insulating screen penetrable using the at least one moving contact piece so as to make contact between the at least one moving contact piece and the at least one fixed contact piece. The screen is disposed between the at least one fixed contact piece and the at least one moving contact piece.