A study of the variation of synchronous machine parameters due to saturation: a numerical approach

• Published in: Electric power systems research 2004-11, Vol.72 (1), p.1-11
• Main Authors: Escarela-Perez, Rafael, Niewierowicz, Tadeusz, Campero-Littlewood, Eduardo
• Format: Article
• Language: English
• Subjects: Applied sciences; Electrical engineering. Electrical power engineering; Electrical machines; Exact sciences and technology; Finite-element modeling; Hybrid genetic algorithm; Standstill frequency response; Synchronous machines
• ISSN: 0378-7796; 1873-2046
• DOI: 10.1016/j.epsr.2004.03.001

This paper shows the variation of the fundamental parameters of synchronous machine two-axis equivalent circuits due to magnetic saturation. The different magnetic states of the machine are obtained using finite-element magnetostatic solutions. This way the permeability patterns of the saturable parts of the machine can be stored and used in a specially designed finite-element program that outputs the standstill frequency response (SSFR) of the machine. A hybrid genetic algorithm, capable of finding global extrema is then applied to obtain the parameters of two equivalent circuit structures for the d-axis. The process is repeated for each magnetic state, so that the variation of parameters can be seen. The magnetic states of the machine are validated by comparing the measured open-circuit characteristic with the one calculated from the finite-element model. In order to validate the d-axis equivalent circuit parameters identified, they have been adopted in the simulation of a synchronous machine short-circuit and the results obtained have been compared to those calculated by a transient finite-element program.