Performance Evaluation of Doubly Fed Induction Generator Based Wind Turbine

Abstract

This paper is an analysis of a MATLAB/Simulink model of the Doubly-fed Induction Generation (DFIG)-based wind turbine and its evaluation. It covers the aero dynamic model, rotor and grid side control models and the model of the DFIG. Many authors have presented similar models but this paper develops a Simulink model of the DFIG by using the analytical equations of the DFIG instead of the single DFIG block contained in the Simscape library of the Simulink software. An adequate description of the solution of this analytical model is provided. The control strategy was also implemented using appropriate function blocks in the Simulink environment and some MATLAB scripts. This work evaluates the performances of rotor speed, DC link voltage, rotor active and reactive power and the grid current. The response of rotor speed after wind speed changed from 8 m/s to 10 m/s is provided. The DC link voltage is controlled to a constant value of 1150 V to keep rotor power constant while the reactive power of the rotor is regulated at 0 VAR thereby ensuring that no reactive power is exchanged with the grid. A rise in rotor active power with less torque was observed with the step change in speed. The grid current waveform was observed to be a 50Hz, 3-phase sinusoidal current with amplitude of 500 A Peak to Peak (pk-pk).