The brushless doubly fed reluctance generator (BDFRG) can be an attractive choice for wind power application
where mostly located at remote areas with unbalanced grid voltages, however there is not any
study on the BDFRG under this condition up to now. In this paper, a mathematical model for the
BDFRG under unbalanced grid voltage condition has been developed. Its equivalent circuit in dq reference
frames has been extracted, and the torque and power equations have been derived, all based on the positive
and negative sequence components. Also, a real-time separation method has been proposed to separate
the BDFRG positive and negative sequences. The developed model and equations express the basis
of the BDFRG operation under unbalanced grid voltage condition. The proposed model is simulated in
MATLAB/Simulink software and the accuracy of the proposed model and equations has been validated
by comparison with simulation results of an existing BDFRG model under balanced condition, which
has already been experimentally verified in the literature.