Real Time Simulation of Brushless Doubly Fed Reluctance Generator Driven Wind Turbine Considering Iron Saturation

Abstract

Brushless doubly fed reluctance generator (BDFRG) provides a good substitute for the doubly fed induction generator for the wind energy applications due to the nonexistence of the slip rings. Real time modelling of the BDFRG is a challenge due to the high leakage inductance of the stator windings. While the magnetic saturation of the iron parts affects the inductances values, therefore studying the effect of magnetic saturation on the BDFRG performance is important. In this paper, a BDFRG model including iron saturation is built. The finite element (FE) analysis using FEMM software is used to generate the relationship between the generator currents and the inductances, the generated data are recorded in a lookup table. A Simulink model of the BDFRG driven wind turbine, with two cases of constant and variable inductances, are developed and verified with FE analyses at range of wind speeds above and below the synchronous speed. The lookup table proposes is verified using finite element analysis at different modes of operation of wind speed and compared with the constant inductance model to show the importance of saturation inclusion in the generator model for accurate generator modelling representation.