Harmonic Analysis of Type-3 Wind Turbines Subject to Grid Unbalance

The objective of this paper is to adequately model a doubly-fed induction generator (DFIG)-based type-3 wind turbine under grid unbalance by considering not only positive and negative-sequence circuits but also the 3rd harmonic circuit. This sequence component caused frequency coupling with 60-Hz component. It zero-sequence cannot be got rid delta-connected transformers. Hence, accurate modeling necessary capture In addition modeling, we design an efficient algorithm for steady-state analysis formulating problem as optimization problem. A set equality constraints has been formed reflect relationship voltage, current, power in ac circuits, dc circuit, different frames. formulation defined YALMIP, MATLAB interface problems. then solved nonlinear solver. results are phasors components at steady state. They have validated obtained from Fourier transforms electromagnetic transient (EMT) simulation results. contributes both sophisticated phasor DFIG consideration computing procedure use advanced solvers.