Fanon
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Old text as well: A slow motion caption of an electrical arc that burns between two electrodes as they move apart. The AC current crosses zero and the arc re-ignites. The light channel is air heated into plasma by the current that flows between the contact members. In my master thesis I am going to analyze the plasma channel's path during current interruption to see how effective air cooling is to quench an arc.
theboatsong
So is this a "Taser" trailer for your thesis?
YuffieK
MoreCatsThanSense
"current interruption to see how effective air cooling is to quench an arc." <<== Look up 'Air Blast Circuit Breakers' They've been in use for years, the technology is well established.
Fanon
Well yeah. We of course know that. But they technology is expensive both to build and maintain and quite ineffective so they where mainly replaced by SF6 based circuit breakers. And you often needed several air blast circuit breakers in series to break high short circuit currents at higher voltages like 420kV.
This project was a part of a new generation of switches replacing SF6 with air but way more efficient than the old air blast ones. Using the same "form factor"
MoreCatsThanSense
A fresh look at old technology is always good, will be interesting to see what you come up with. I know of several 1960's era 400kV ABCB's still in service (Retired Electrical Engineer).
Fanon
Since I delivered my thesis 10 years ago I can give an update already. The technology developed by the research team I was a part of have been implemented in products from both ABB and Siemens. In general we optimized a lot of details wich was not engineered properly on the old circuit breakers like air flow, pressure, nozzle design and contact points making it possible to move from a high pressure system to a puffer based one.
Fanon
I am not sure about the highest current ratings and voltage ratings but it's pretty common on medium voltage lvl replacing expensive vacuum designs or environmental harmful SF6 solutions. At least for some applications.