An Analytical Model and the Comparative Simulation for Stand-Alone Operated DFIG

A stand-alone operated doubly-fed induction generator (DFIG) exhibits different characteristics than those connected to grids. Therefore, this study proposes a realistic analytical model to investigate the behavior of the stand-alone DFIG, through simulations. The study examines the validity of several existing analytical models of DFIG and focuses on one in particular, which is derived from the stator and rotor voltage equations in the separate (natural) reference frame. This model is built using Matlab/Simulink conventional building blocks and simulated to explore the behaviors of a stand-alone DFIG in transient and steady-state, under no-load and linear/non-linear load conditions. To verify the accuracy of the proposed model, it is compared with two different pre-built DFIG models in Simulink and in Plecs. The comparative simulations, carried out simultaneously under the same conditions, verify the validity of the proposed analytical model. As the advantages, the proposed model is easy to build, runs faster compared to pre-built Simulink model and is also convenient for analyses of stand-alone DFIGs for real operational conditions.