Sieć Badawcza Łukasiewicz - Instytut Napędów i Maszyn Elektrycznych Komel
Abstract
3D finite element method was used in this article to calculate inductance matrix of the autotransformer, divided into eigenvectors [W] and eigenvalues [D]. The autotransformer windings were powered by monoharmonic voltages. This method, as an equivalent of the short circuit tests, is more suitable for calculating small values of leakage inductance. The equivalent are here the methods which are using feeding the autotransformer windings by fixed currents (it is equivalent of the idle running tests). The relationship between autotransformer inductance matrix and ripple was obtained. It appeared, that eigenvectors matrix of the inductance matrix of the autotransformer is almost independent from the ripple, and its elements are real numbers. It was treated as transformation matrix: flux linkages - windings currents flows. Relation from the ripple of the eigenvalues of inductance matrix was synthesized by means of ladder circuits. As a result the exact substitute diagram of the autotransformer was obtained. This article is the third one out of four articles presented at this Seminar
