A Direct Method for Calculation of Steady-state Operating Conditions of a Doubly Fed Induction Generator

Abstract

Sharing reactive power burden between the rotor side converter (RSC) and grid side converter (GSC) under normal conditions reduces the burden on RSC and improves its lifetime expectancy. In this paper, a non-iterative or direct method for calculation of steady-state operating points of a doubly fed induction generator (DFIG), considering non-zero reactive power flow through grid side of DFIG, is developed. The approach also considers grid side filter losses. The direct initialization method is applied on both subsynchronous and supersynchronous steadystate models of DFIG. A comparison of initial values obtained at various modes of operation of DFIG is conducted. The approach helps in accurate initialization of DFIG in both subsynchronous and supersynchronous modes. The non-iterative approach also prevents non-convergence issues and significantly reduces the calculation time of DFIG internal variables.