Does AAC and 4/0 CU hard drawn change reactance with temperature?
Yes. All metals do. Don’t they teach this in school anymore?
Read about Temperature Coefficient of Resistance (Physics Of Conductors And Insulators) in our free Electronics Textbook
www.allaboutcircuits.com
DC resistance changes by quite a bit. But since you mentioned AAC, sag changes a lot, which affects the GMR term. Plus length changes a lot too.
Most utilities at some point just calculate some kind of average and somebody comes up with tables of standard pole designs and they never look back. In mountains they do a lot more cad work but the structures are once again relatively fixed. They might have just measured it or use whatever designs don’t fall down (too much). In coastal hurricane prone areas or mountains you get a little different approach because you can’t just take RUS at face value for instance.
It’s only when you run into situations that cannot be answered by “the book” that you might go back and do the basic engineering. The impedance calculations are easy but the geometrical data isn’t because sagging power lines are hyperbolic functions and all the math is very nonlinear.
So either empirical equations or finite element software drives everything. That’s why you will run into a brick wall trying to find data. Back “in the day” Alcoa did all the experimental work and created a book of monographs of every kind of AAC, ACSR, some copper stuff, and so on called the Sag book. You can approximate sag in roughly horizontal terrain with a Taylor series expansion with only a couple terms. The book still exists (updated) and the monographs have been converted to software. South wire sells the software (SAG10) and the book. Better engineering models have been developed, way beyond SAG10, but if all you want is impedance data and you are doing just roughly horizontal terrain, the book has tables that get you within 5-10% error cheaply.
