Title :
Iron loss and saturation in brushless doubly-fed machines
Author :
Ferreira, Antonio C. ; Williamson, Sheldon
Author_Institution :
COPPE, Univ. Federal do Rio de Janeiro, Brazil
Abstract :
The stator of a brushless doubly-fed machine (BDFM) is furnished with two sets of three-phase windings. These windings always have different pole numbers and are generally supplied at different frequencies. Investigation of the field distribution in a BDFM indicates that no polar symmetry can be associated to it. In addition the motion of the field is not a simple rotation as in a induction motor. Therefore it is not expected that the representation of saturation by means of traditional saturation factors will yield useful results. In this paper, the authors describe a time-stepping finite-element model for the BDFM which can readily represent the effect of saturation. In addition, it is shown that iron losses can be calculated as the time-stepping solution proceeds. The model is verified using measurements made on a test machine. The use of saturation factors in conjunction with an analytical model is also investigated
Keywords :
brushless machines; finite element analysis; losses; machine theory; magnetic fields; stators; brushless doubly-fed machines; field distribution; iron losses; pole numbers; saturation representation; stator; three-phase windings; time-stepping finite-element model; Coupling circuits; Finite element methods; Frequency; Induction motors; Iron; Machine windings; Power system modeling; Stator windings; Testing; Voltage;
Conference_Titel :
Industry Applications Conference, 1997. Thirty-Second IAS Annual Meeting, IAS '97., Conference Record of the 1997 IEEE
Conference_Location :
New Orleans, LA
Print_ISBN :
0-7803-4067-1
DOI :
10.1109/IAS.1997.643014