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Problems that HVDC( high-voltage di rect current) engineers encountered and maneuvers in the futur e constructing electricity superhighways.
By Curry conducted by Ms.Alannah
With the development of the entire world, the need of the electricity consumption can not be alleviated, instead, it is aggravating. The problem in the reality is that we have to convey the electrical energy from a certain place to another, while we are actually facing different conditions all around the globe such as high-rising mountains and the deepest sea, and thanks to those physical and geographical engineers for their contribution to establishing electricity superhighways.
The history of HVDC can date back to 1882, by Oskar Von Miller and fellow engineers. ( HYPERLINK "http://www.edisontechcenter.org/OskarVonMiller.html" Oskar Von Miller, engineering pioneer and founder of the Deutsches Museum ) It was the first successful HVDC experimental long distance line 37 miles made at Munich. Their important early DC work laid the foundation for future developments.
The fact that scientist found is with the distance going on and on, the energy proves to be less and less in a particular voltage. (Direct current) A apparatus called thyristor can change DC into AC. And then scientist used alternating current(AC) to build superhighways to convey the energy cause AC could go further than DC. Unfortunately, every thing has its limitations, the problem that hinders the energy convey the most is the landform of the place where superhighways needed. At present, I regard China as an example. The gross landform of China tends to be high in its west part of the territory. Especially in Tibet, its average elevation altitude is over 4000 meters. How can we transform the electricity to that high?
In these kind of condition, the superhighways seems to be more significant. They are built in the mountain with many of wirecables connected with each other. And lately there has been a new theory that radio electricity transmission can be applied in long-distance electricity convey. Instead of using wirecables, scientists developed wireless way that transforms the electricity energy. However, its efficiency is not seemed well after the test, and with the distance going further and further, its efficiency seemed getting less and less. While it is worthwhile to develop this kind of system to achieve long-distance electricity transmission without wires and high-rising towers that carry a lot of equipment.
If we can not transform the electricity from low to high, we can produce electricity from high to generate electrical appliances there. Since the west part of China has the highest elevation altitude, it can fit with the solar energetic infrastructures. For instance, installing solar panel to provide them electricity itself which is also a good scheme that solves the problem that wire-superhighways are tough to be built in the mountains.
In a way, those schemes above are just fit to deal with one of the aspects from those limitations. Let us have a look on the long-distance electricity transmission system in Asia. The one that connects China, Vietnam and Philippines goes through under the sea level. This is called subsea-transmission. The only problem is that the wire will be decayed gradually by the sea, and some times the marines will also bite the wires under the sea. It has always been annoying that it is hard to check and fix the broken wire. Besides, broken wires will lead to environmental pollution if they are not taken out appropriately.
At present, there is no any useful solution or improvement for subsea-electrical transmission. And we got a long way to go and explore the advanced technology to settle those to make a difference.
http://www.edisontechcenter.org/HVDC.html Paragraph 2
g electricity superhighways.