Dynamic Behaviour of a Wind Energy Conversion System including Doubly-Fed Induction Generator in Fault Conditions

Abstract

In this paper, the behaviour of a wind energy conversion system that uses the structure of Doubly-Fed Induction Generator (DFIG) under faulty conditions is presented. DFIG consists of an asynchronous machine, in which the stator is connected directly to the grid and its rotor is connected to the grid via two electronic power converters (back-to-back converter). In the three-phase rectifier and the inverter with IGBTs the Pulse Width Modulation (PWM) technique is used. DFIG is analysed and simulated under faulty conditions in the environment of Matlab/Simulink. The faults that are investigated in this work take place in the part of the back-to-back converter (either in the rectifier or in the inverter). More specifically, it is investigated how DFIG reacts when an open circuit happens in two IGBTs of the rectifier or of the inverter. Also, the results of Fourier analysis of some important system variables in these faulty conditions are presented and an identification of these faults is done.