Segmented Contact Pin for High-Voltage Switches

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Solution Overview

Problem

Existing contact pins and tubular contacts for high-voltage and medium-voltage switches face challenges in withstanding arcing and erosion, leading to material burn-off and increased costs due to the need for expensive arc-resistant coatings.

Innovation Solution

A contact pin design featuring a refractory metal contact tip and a heat-resistant carrier sleeve, where the carrier sleeve is made of a less expensive material and connected to the contact tip via back casting or other joining techniques, reducing the overall cost and weight while maintaining electrical and thermal conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the entire contact pin is made of arc-resistant refractory metal, then erosion resistance is improved, but material cost and weight increase significantly

Engineering Contradiction:
Improveerosion resistanceVSAvoidcontact pin weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The contact pin is divided into two functional segments: a contact tip made of arc-resistant refractory metal (tungsten, molybdenum, or their alloys) and a carrier sleeve made of less expensive material (copper, aluminum, or their alloys). This segmentation allows each part to be optimized for its specific function while reducing overall cost and weight.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The arc-resistant refractory metal is applied locally only to the contact tip where arcing and erosion occur during switching operations. The carrier sleeve in non-arcing areas uses lighter, less expensive materials, providing local optimization of material properties where needed without unnecessary weight elsewhere.

Inventive Principle:
Principle #3Local quality

2Reliability

If expensive arc-resistant coatings are applied to protect the base body, then erosion resistance is improved, but manufacturing cost increases

Engineering Contradiction:
Improveerosion resistanceVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

Instead of applying protective coatings to an entire base body, the design segments the structure into a refractory metal contact tip and a metal alloy carrier sleeve, eliminating the need for expensive arc-resistant coatings on the base body while maintaining protection where needed.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The carrier sleeve is made of less expensive metal alloys that, while not arc-resistant, are sufficient for the non-arcing portions of the contact pin. This replaces expensive protective coatings with cost-effective material selection for appropriate applications.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Reliability

If heavy refractory metal is used throughout the contact pin, then arc resistance is improved, but drive system cost increases

Engineering Contradiction:
Improvearc resistanceVSAvoidcontact pin weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The contact pin is segmented into a refractory metal contact tip for arc resistance and a lighter metal alloy carrier sleeve for structural support, reducing overall weight while maintaining necessary arc resistance at the contact interface.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Arc-resistant material is concentrated locally at the contact tip where arcs occur, while the carrier sleeve uses lighter materials in non-arcing areas, optimizing the weight-to-performance ratio and reducing drive system requirements.

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

The solution effectively prevents erosion and reduces material costs by utilizing a refractory metal contact tip and a heat-resistant carrier sleeve, enhancing the contact pin's durability and conductivity, and allowing for more cost-effective drive systems due to reduced weight.

Implementation Method 1

The carrier core and carrier sleeve are preferably connected to one another with a material fit (metalurgical bonded) in order to provide a stable connection between the two elements. The carrier core is particularly preferably cast into the carrier sleeve.

Methodology Applied
Scientific EffectBack casting:

Implementation Method 2

The contact pin has a contact tip made of a material that is resistant to erosion or arcing, in order to prevent such a erosion. For example, the contact tip can be made of a refractory metal or an alloy based on a refractory metal, so that it can withstand the arcs and the high temperatures that occur in the process.

Methodology Applied
Scientific EffectArc resistance:

Implementation Method 3

The carrier core is preferably made of a material with good electrical conductivity. The carrier core is preferably made of copper or aluminum or of an alloy based on copper and/or aluminum.

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 4

maintaining electrical and thermal conductivity

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3108489B1Contact pin and pipe contact, and method for production
Publication Date: 2019.01.16 PLANSEE POWERTECH
  • EP3108489B1 patent drawingFigure 1a~4
  • EP3108489B1 patent drawingFigure 2a~3b

AI summary

Contact pin (2) and pipe contact for high- and/or medium-voltage switches and method for producing a contact pin and pipe contact, wherein the contact pin (2) has: a contact tip (4) which is composed of a fire-resistant material, and a tubular carrier sleeve (6) which is connected to the contact tip (4), a carrier core (8) which is moulded into the carrier sleeve (6), wherein the contact tip (4) is arranged in a front region of the contact pin (2), in which front region arcs occur when the contact pin (2) is in use, and wherein the carrier sleeve (8) is arranged in a rear region of the contact pin (2), which rear region adjoins the front region and in which rear region no arcs occur when the contact pin (2) is in use, wherein the pipe contact has: a fire-resistant contact ring, and a carrier pipe which is connected to the contact ring, wherein the contact ring is arranged in a front region of the pipe contact, in which front region arcs occur when the pipe contact is in use, and wherein the carrier pipe is arranged in a rear region of the pipe contact, which rear region adjoins the front region and in which rear region no arcs occur when the pipe contact is in use.