146 research outputs found
Robust Causality Check for Sampled Scattering Parameters via a Filtered Fourier Transform
We introduce a robust numerical technique to verify the causality of sampled
scattering parameters given on a finite bandwidth. The method is based on a
filtered Fourier transform and includes a rigorous estimation of the errors
caused by missing out-of-band samples. Compared to existing techniques, the
method is simpler to implement and provides a useful insight on the time-domain
characteristics of the detected violation. Through an applicative example, we
shows its usefulness to improve the accuracy and reliability of macromodeling
techniques used to convert sampled scattering parameters into models for
transient analysis
MoM-SO: a Complete Method for Computing the Impedance of Cable Systems Including Skin, Proximity, and Ground Return Effects
The availability of accurate and broadband models for underground and
submarine cable systems is of paramount importance for the correct prediction
of electromagnetic transients in power grids. Recently, we proposed the MoM-SO
method for extracting the series impedance of power cables while accounting for
skin and proximity effect in the conductors. In this paper, we extend the
method to include ground return effects and to handle cables placed inside a
tunnel. Numerical tests show that the proposed method is more accurate than
widely-used analytic formulas, and is much faster than existing proximity-aware
approaches like finite elements. For a three-phase cable system in a tunnel,
the proposed method requires only 0.3 seconds of CPU time per frequency point,
against the 8.3 minutes taken by finite elements, for a speed up beyond 1000 X.Comment: This paper has now been published in the IEEE Trans. on Power
Delivery in Oct. 2015, vol. 30, no. 5, pp. 2110-2118. DOI:
10.1109/TPWRD.2014.237859
An improved fitting algorithm for parametric macromodeling from tabulated data
This paper introduces a new scheme for the identification of multivariate behavioral maeromodels from tabulated frequencydomain data. The method produces closed-form parametric expressions that reproduce with excellent accuracy the external port behavior of the structure, both as function of frequency and one or more external parmeters. The numerical robustness of the main algorithm is demonstrated on two significant examples
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