Monday, September 18, 2006

More Evidence Alta Link plan is one of Export not domestic.

Electrical engineeer comes out against the published reasons:

Mr. Rolf,

If ALTALink were to adopt your idea we'd be into worse problems than we have had with deregulation because your idea simply would not work!

Firstly the doubling of alternating current in the same or even doubling the crossectional area of conductors in alternating current circuits would not make the voltage drop significantly less. This is because most of the voltage drop in transmission lines is not due to resistance: at heavy currents: it's largely due to "inductive reactance". That is caused by the fact that there is a "flywheel effect": perhaps you have experienced the shock you receive when you touch an electric fence on a farm? Once a current starts to flow it requires an effort to stop it and reverse its direction and that is what electrical engineers refer to as "inductive reactance". While increasing the crossectional area of the conductors will reduce this "inductive reactance" the amount of decrease is really not as significant as you seem to believe.

Secondly, doubling the crossectional area of the conductor, assuming that the percentage of the crossectional area that is steel remains constant, would increase the mass of the conductor by a factor of two. In order to maintain the same ground clearance the tension in the larger conductor would need to be approximately twice as great. That would mean that terminal supporting structures would need to be replaced...that is "guaranteed" and it is quite likely that many of the structures that are in a straight line (we call them tangent structures) would need to be strengthened as well.

While the various supporting structures are being strengthened and the terminal structures are being replaced, the transmission line would need to be out of service i.e. some people would find that they were without electric power.

While I do not have much experience in rebuilding transmission lines, I do have some but it was all a result of force majeure.

By formal education, I am a graduate electrical engineer. By experience, I am an electric conductor engineer which is a specialty in that discipline. I have helped to design transmission lines in many States of the USA, in Quebec, In Iran, in Turkey, and in Saudi Arabia.
You could find my name in the Acknowledgements near the front of "Wind Induced Conductor Motion" which is a textbook published by the Electric Power Research Institute, a corporation established by act of the Congress of the USA to do research for electric utilities. I have seen copies of that textbook in TransAlta and in IREQ, the research arm of Hydro Quebec. Frankly, I don't know why my name appears there. It could have been any one or all of the three authors who suggested that I be acknowledged along with my late friend and co-worker, Ed. Doocy. Yes, I have an American patent and am awaiting a Canadian patent for the same device.

K. Allan Dane, M.Sc.(EE)
adane@telusplanet.net.
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