AbstractsEngineering

Parametry nahradniho obvodu synchronniho stroje znance ovlivnuji jeho chovani jak pri statickem provozu, tak predevsim pri nahlych dynamickych jevech a poruchovych stavech. Prace je zamerena na zhodnoceni dostupnych metod pro vypocet techto parametru pomoci Metody konecnych prvku. Prvni cast je venovana teoretickemu popisu zakladnich principu Metody Konecnych Prvku a jejich aplikaci na reseni problemu elektromagnetickeho pole v elektrickych strojich. Zaroven take shrnuje zakladni usporadani nahradniho obvodu synchroniho stroje, principi jeho konstrukce a zakladni funkci. Druha cast je venovana praktickemu vypoctu reaktanci nahradniho obvodu synchronniho stroje. S pomoci MKP jsou vypocteny synchronni reactance s uvazovanim vzajmeneho magnetickeho pusobeni proudu v d a q ose. Pro vypocet transientnich a subtransientnich reaktanci jsou navrzeny ctyri odlisne metody a jsou zhodnoceny z hlediska pozadovane presnosti vypoctu a narocnosti na vypocetni cas. Zaverecna cast popisuje zakladni merici metody pro urceni parametru nahrandniho obvodu na skutecnem stroji. Kapitola take obsahuje srovnani simulace trifazoveho zkratu synchronniho stroje s realnou zkouskou provedenou laboratorne. Zaver obsahuje srovnani jednotlivych metod a navrh optimalniho postupu pro vypocet zkoumanych parametru.; Equivalent circuit parameters of synchronous machine greatly affects it’s performance during steady state operation and also during faults and transients. This thesis is focused on investigation and evaluation of different methods, for calculation of equivalent circuit parameters, based on the Finite Element Method. First section gives theoretical overview of basic Finite Element Method principles and application on the magnetic field problems in electric machinery and fundamental concepts of synchronous machine operation and equivalent circuits, for different operation stages are discussed. Second section is focused on identification of equivalent circuit parameters of four pole synchronous generator. Magneto-static FE simulation is used for calculation of synchronous reactances with cross coupling taken into account. For calculation of transient and subtransient parameters, four different methods are proposed and they are evaluated with respect to the accuracy and computation time. Final section describes basic test procedures for synchronous machine equivalent circuit parameters estimation. Chapter also covers comparison of FE based simulation of dead short circuit at machine terminals and real test carried out in the laboratory. Summary gives a review of proposed methods and comparison of different approaches.