Contribution à la commande d’une génératrice asynchrone à double alimentation en présence d’asymétries d’excitations statoriques

Abstract

The development technologies relating to the wind energy conversion into electrical energy in order to satisfy the growing demands on the existing electrical networks represents a very important issue among other the other renewable energy existing resources. This trend is justified by its ability to be implemented on large scales with respect to environmental requirements. The doubly-fed induction machine (DFIM) equipped with two static converters and driven by a wind turbine is the simplest and most efficient ways for converting the stored energy in the wind into electrical energy sent directly to the distribution network in the form of active and reactive powers. By the use of different field oriented control strategies, each of these two kinds of power could be controlled separately. The design of control laws that governing the operation of the DFIM based wind energy system conversion is conventionally based on the vector control technique application which consists in controlling the electromagnetic torque and the flux of this machine in a similar way of that of the separated DC machines under the assumption that network to which the stator of the DFIM is connected must be perfectly balanced. Nevertheless, as a real network voltage is usually affected by a given asymmetry, the above assumption can never be realized. The aim of this work is to find a way to make the classical vector control still applicable in the case of an unbalanced utility.