2 / 2018-11-20 21:35:17

Comparison of DFIG dq and abc Reference Models Under Unbalanced Electrical Grid Conditions

DFIG Equivalent Model, abc Versus dq Comparison, Grid-Unbalance.

This work presents a comparative analysis between
two representative models of the double-fed induction generator
(DFIG). Initially the modeling of the machine in the abc coordinate
system is described without considering simplifications
in order to properly represent all the variables. The second
representation is made in the synchronous reference frame, or
dq, using the Park transform, where by means of the reference
change it is possible to simplify the variables with the equivalent
circuit of the meshes of the direct axis and the quadrature
axis. The analysis presents the main differences between the
equivalent models in abc and dq under unbalanced conditions
of the electrical grid. The representation in abc coordinates
been more adequate because during an unbalance there is
loss of information of the zero sequence component in the
dq model that does not faithfully characterize the behavior of
the electromagnetic torque and currents of the generator for
such conditions. The work approach is based on application
that involve network unbalances, reactive compensation, active
filtering and any non-sinusoidal condition, since they require a
modeling that includes all characteristics and variables of the
machine without simplifications.