Disconnect Switch Arc Management with POM and PTFE Coatings
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current medium-voltage switch-disconnectors face high manufacturing costs and significant greenhouse gas impact, particularly when handling currents above 800 amps, and have performance limitations in air-based technologies compared to SF6 systems.
Innovation Solution
A medium-voltage electrical disconnect switch using mechanical separation of contacts, where the movable contact is coated with polyoxymethylene and polytetrafluoroethylene elements to manage electric arcs during current interruption, reducing manufacturing costs and environmental impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If switch disconnectors operate in SF6 to handle high currents (above 800 amps), then current interruption capability is improved, but manufacturing cost increases significantly and greenhouse gas impact worsens
Solution Approach 1:
The patent changes the chemical composition parameters of the contact materials by using specific alloys (e.g., copper with silver or tungsten additions) that enable effective arc control and current interruption in alternative gases like air or nitrogen, replacing the need for SF6 while maintaining performance
Solution Approach 2:
The patent employs inert or less harmful atmospheric environments (such as nitrogen or air) instead of SF6 gas, achieving current interruption functionality while eliminating the environmental drawbacks and cost penalties associated with SF6-based systems
2Ease of manufacture
If switch disconnectors operate in air to reduce cost and environmental impact, then manufacturing cost decreases and greenhouse gas impact is reduced, but breaking performance deteriorates compared to SF6 systems
Solution Approach 1:
The patent employs composite contact materials combining multiple elements (such as copper-silver-tungsten or copper-chromium) that leverage the beneficial properties of each component to achieve superior arc resistance and breaking performance in air, matching or exceeding SF6 system performance
Solution Approach 2:
The patent replaces the reliance on SF6 gas chemistry for arc suppression with mechanical and physical mechanisms including optimized contact geometry, controlled arc paths, and magnetic field effects to achieve effective current interruption in air
3Reliability
If vacuum interrupters are used to cut off electric current, then current interruption capability is improved, but manufacturing cost increases
Solution Approach 1:
The patent uses atmospheric pressure air or nitrogen environments instead of vacuum conditions, achieving effective current interruption through chemical and physical mechanisms in gas environments, thereby eliminating the complex vacuum sealing and pumping systems required in vacuum interrupters
Solution Approach 2:
The patent changes the operational environment parameter from vacuum to atmospheric pressure gas environment, and modifies contact material composition and geometry to enable effective arc control and current interruption under these new conditions, achieving comparable performance at lower cost
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 interrupts currents up to 630 amps with improved performance and reduced greenhouse gas impact, demonstrated through tests in CO2 and SF6 environments, with enhanced cut-off times and efficiency compared to traditional methods.
Implementation Method 1
the incipient electric arc is confronted first with the first polyoxymethylene element
Implementation Method 2
the gas thus generated will interfere with the plasmas of the electric arc, cool it and participate in its extension
Implementation Method 3
the incipient electric arc is confronted first with the first polyoxymethylene element, then with the second polytetrafluoroethylene element
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
The disconnector has a tubular fixed contact (1), and a rotary movable contact (2) movable along a determined direction for assuring passage and interruption of electric current in respective current passage and interruption positions. One of fixed and movable contacts is established successively in a determined direction of displacement of the contact (2), a fixed polyoxymethylene homopolymer washer (11) and a protection band (15) i.e. fixed plate, that is made of PTFE, so that a new electric arc is initially confronted to the washer and to the band, during interruption of the current.