Talk by William Johns (Mathematical Sciences, MSU)

10/17/2019  Wilson Hall 1-144  3:10-4:00pm

Abstract:  Rational approximations are commonly used in frequency dependent modeling of electromagnetic transients in transmission lines. The most commonly used rational approximation algorithm in this industry is Vector Fitting. A key feature of Vector Fitting is the approximation of multiple inputs over a common set of poles. The common set of poles is important for reducing computation time in the models. However, Vector Fitting is known to have some shortcomings. We propose a new multi-input algorithm based on the AAA algorithm for use in these models. We demonstrate that this approach yields an accurate and robust algorithm and leads to some additional interesting problems.