14MV would be capable of sustaining an arc 1400 feet long in normal atmosphere. I struggle to imagine how you'd build such a thing. You could maybe have a high volume sf6 pump system that would cool and quench the arc on breaker trip with a constantly replenished sf6 supply.
Isn't sf6 on the way out due to it being an extremely potent GHG?
Not sure what the alternative would be for really high voltages? Vacuum insulated switchgear seems to be a hot topic at the moment, but not sure how it'd work with such extreme voltages?
Even 1.1GV systems use semiconductor breakers. Basically, stacks and stacks of transistors. The actual physical breakers are only operated when the voltage is safely off.
I considered that. Considering the cheap cost of the cable, the best solution appears to simply be 'dont have a breaker'. In either over current or over voltage conditions, simply sacrifice the cable.
Obviously you engineer the convertor stations to minimize the chances of that happening - stopping the convertors automatically if anything looks abnormal. The cable has sufficient capacitance that you have multiple milliseconds to respond, so automated systems should have no difficulty.
14MV would be capable of sustaining an arc 1400 feet long in normal atmosphere. I struggle to imagine how you'd build such a thing. You could maybe have a high volume sf6 pump system that would cool and quench the arc on breaker trip with a constantly replenished sf6 supply.
Isn't sf6 on the way out due to it being an extremely potent GHG?
Not sure what the alternative would be for really high voltages? Vacuum insulated switchgear seems to be a hot topic at the moment, but not sure how it'd work with such extreme voltages?
GE has some replacement gas, I'm not sure of the composition, but it isn't as good as SF6 unfortunately.
Even 1.1GV systems use semiconductor breakers. Basically, stacks and stacks of transistors. The actual physical breakers are only operated when the voltage is safely off.
1.1MV?
D'Oh. Of course.
I considered that. Considering the cheap cost of the cable, the best solution appears to simply be 'dont have a breaker'. In either over current or over voltage conditions, simply sacrifice the cable.
Obviously you engineer the convertor stations to minimize the chances of that happening - stopping the convertors automatically if anything looks abnormal. The cable has sufficient capacitance that you have multiple milliseconds to respond, so automated systems should have no difficulty.
> simply sacrifice the cable
How is that different from a fuse?
If I said to build a 3000 kilometer fuse and quench it with the entire Atlantic ocean, people would tell me I was being silly.
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