Modelagem e controle de conversores de interface de sistemas eletromecânicos de conversão de energia eólica baseados em geradores síncronos de ímãs permanentes

Abstract

This work presents the modeling and control of a variable speed wind energy conversion system connected to the mains. Two topologies full capacity power electronic converters are investigated as interface circuit. The grid-side converter of both circuits is composed of a voltage source inverter with an LCL filter connected to its output terminals. On the generator-side, the performance of an uncontrolled three-phase rectifier, with a boost converter connected to the DC terminals, and a two-level voltage source rectifier, with PWM modulation and L filter, are investigated as rectifier. The mathematical models of the two converter arrangement topologies and the permanent magnet synchronous generator are developed in the synchronous (dq0) coordinates systems. The control of the converters is done in the state space and the gains of the feedback loops are calculated using a linear quadratic regulator method. The algorithm for tracking the maximum power point of the permanent magnet generator determines the reference mechanical angular speed value based on the optimal tip speed ratio of the blade. In addition, a control of the angle of attack of the wind turbine blade is carried out. A method to design the DC bus capacitor is proposed for the two-level back-to-back converter. Simulation results obtained in the electromagnetic transient program PSCAD/EMTDC are used to verify the modeling and the controllers designed for two of the investigated converter topologies