The LitzOpt Program
program to optimize transformer litz wire strand design by minimizing
costs and power losses.
Litz wire is typically used when operating frequencies are high enough
to degrade the performance of magnetic components
(10 kHz–1 MHz). The main advantage of using litz wire
is that it reduces eddy-current losses. LitzOpt offers an array of
design alternatives, ranging from more expensive, very low loss-designs
to low-cost higher-loss designs. Typically, all of these alternatives
vastly decrease costs or losses relative to standard rule-of-thumb
designs, and many of them offer improvements in both cost and loss. The
algorithm used in LitzOpt is explained in detail in "Optimization of a
flyback transformer winding considering two-dimensional field effects,
cost and loss." This paper and related papers can be downloaded from here.
LitzOpt can be used to minimize winding loss in transformers with
multiple windings, arbitrary waveforms, and two-dimensional or
three-dimensional field geometry. Waveforms are entered into LitzOpt as
piecewise linear. LitzOpt can optimize a transformer stranding design
considering one-dimensional and two-dimensional field effects.
Optimization accounting for three-dimensional field effects requires the
user to perform a numerical field solution with any third-party finite
element or other numerical field solution software. To simulate, the
user is to model the entire region of the windings as regions of uniform
current density to simplify calculations (see 'Obtaining the Squared Field'). The
required magnetostatic field simulation is far more computationally
efficient than a full-blown field simulation and all that is to be
computed is the spatial integral of squared flux density over the
winding cross-sections (considered as regions of uniform current
LitzOpt begins with a fixed number of turns, core geometry, and winding
configuration and optimizes the number and diameter of strands. LitzOpt
assumes that the wire is small compared to a skin depth
(d < δ).
What software do I need? Where do I download?
LitzOpt is for use with Matlab Version 5 or 6, available from MathWorks for a variety of
platforms. Download LitzOpt here.
For Help or Instructions
For comments or questions e-mail: Charles.R.Sullivan@dartmouth.edu.
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