by Dennis Feucht, Innovatia Laboratories, Cayo, Belize, How2Power Today, Oct 16 2017
Focus:
In part 1, the influence of various winding design parameters on eddy current effects
was analyzed and expressed as Fr, the constant-frequency resistance ratio for wire
strands. However, for actual design purposes, what’s needed is a version of this
resistance ratio that applies to the bundles of strands that comprise the winding
turns. This parameter is known as fr and this part 2 presents two methods for achieving
minimum fr in winding designs. The first method is a graphical approach in which
Dowell’s equation is expressed as fr and plotted under different design constraints
such as constant number of layers, constant number of strands, and constant area. The
graph is then used to identify ξr operating point (op-pt) values. The second method
derives design formulas that can be used to calculate the ξr op-pt values. Finally, a
winding design procedure is described that makes use of the op-pt formulas.
What you’ll learn:
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