Controle escalar sensorless para sistemas de conversão de energia eólica com gerador síncrono de ímãs permanentes

Abstract

This master thesis proposes a control method of scalar direct torque control and a technique of current control to maximize the aerodynamic efficiency of wind energy conversion systems (WECS) using permanent magnets synchronous generators (PMSG) with non-salient poles. The maximum power point tracking (MPPT) is possible to apply optimum torque to the generator by just controlling the static converter. Two topologies are addressed: The first one is a boost converter, widely used in WECS, where the MPPT method is implemented by the controlling the boost inductor current; and the second is a three phase AC boost converter where the scalar direct torque control is proposed. Aims to reduce the mechanic speed sensor a work with sensorless algorithms, is proposed. First an observer in the continuous time domain in coordinates αβ is developed containing two observers: a current sliding mode whose function is to determine the electromotive force (EMF) and EMF observer which aims to determine the rotor speed based on the direct method of Lyapunov. After, in the discrete time domain, sliding mode observers of speed and rotor position are described. Simulation and experimental results are presented to validate the theoretical analysis and demonstrate the good performance of the techniques to drive PMSG.