This paper presents a detailed dynamic model, by which the dynamic behaviour of Brushless
Doubly-Fed Induction Machine (BDFIM) can be successfully predicted. The investigated douhly‌fed machine has two sets of three-phase stator windings with different pole numbers. The rotor is
a squirrel-cage type with a simple modification in order to support the two air-gap rotating fields
that are produced by the stator windings and have different pole numbers. The machine model is
derived in both natural-machine variables abc-axis and qdo variables axis. The qdo- nxis is
attached to rotor and hence, it mtates at the rotor speed (a, ). The electromagnetic torque
expression is also obtained based on the two presented models. The winding function method is
presented as a convenient approach that can be used for machine-winding inductances
calculations. Sample case studies are introduced to examine the performance of the proposed
model.