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Abstract
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Brushless Doubly-Fed Induction Generator
(BDFIG) has substantial benefits, which make it an attractive
alternative as a wind generator. However, it suffers from lower
efficiency and larger dimensions in comparison with the Doubly-
Fed Induction Generator. A major part of drawbacks arises from
undesirable spatial harmonics of air-gap magnetic field.
Calculation of core loss is an important issue in optimal design
studies to improve the performance characteristics. The iron loss
is higher and has a more complex nature in BDFIG in contrast
with conventional machines. Furthermore, additional losses
cannot be ignored due to high level of spatial harmonics
distortion. This paper aims to formulate core loss and stray load
loss (SLL) in BDFIG based on the design data and experimental
parameters provided by electrical steel manufacturers. In
addition, an analytical procedure for calculating spatial
harmonic components of the stator and rotor magnetic fields is
presented. The acceptable accuracy of the theoretical equations is
verified by comparing the calculated core loss and SLL of a D-
180 prototype BDFIG with the measured data. The results show
that SLL in BDFIG is higher than the predicted per-unit values
given by standards for induction machines, e.g. IEC 60034~2 and
NEMA MG1.
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