Steady-state Initialization of Doubly Fed Induction Generator Based Wind Turbine Considering Grid Side Filter

Abstract

In this paper, a steady-state initialization method for a doubly fed induction generator (DFIG) based wind turbines including grid side (GS) filter equations is discussed. The approach employed considers factors like non-zero grid side converter (GSC) reactive power and GS filter losses. As per the recent grid code requirements, DFIG should be able to participate in reactive power support to maintain voltage stability during faults. Also GSC acts as STATCOM by its structure and supports in damping inter-area oscillations. Above conditions mandates to consider the non-unity power factor operation of GSC. The approach employed also considers GS filter losses, by which an accurate initial values can be obtained. Dynamic evaluation of the steady-state values obtained are performed using eigenvalues and time-domain simulations. The studies are performed on a single-machine-infinite-bus (SMIB) system and the results are compared with dynamic results with a case wherein GS currents are considered as dummy states.