An efficient maximum power point tracking algorithm and control for variable speed wind energy conversion system

Abstract

Variable speed wind energy conversion systems (WECS) have become very popular in newlinerenewable energy world for last few decades. Variable speed operation allows wind turbine to newlinemove with a speed proportional to the wind speed to achieve optimal aerodynamic newlineperformance. A number of techniques have been developed to achieve optimal performance newlinefrom WECS. The most popular techniques are power signal feedback (PSF), tip speed ratio newline(TSR) and perturb and observe (PO) method. PSF and TSR are model dependent techniques. newlineThe drawback of model dependent techniques is that it requires system restructuring for each newlineWECS. Although PO is a non-model based technique but due to slow convergence rate, newlinesystem efficiency is compromised. In this work, an attempt has been made to overcome the newlinedrawbacks of existing techniques. newlineThis work presents a variable speed wind energy conversion system based on squirrel cage newlineinduction generator connected to electrical grid via power electronic interface, which is matrix newlineconverter in this case. In this work the matrix converter is the power electronic converter, newlinewhich is an interface between the squirrel cage induction generator and electrical grid. The newlinematrix converter actuates the control parameters and controls the wind turbine shaft speed. The newlinemechanical power captured by the wind turbine is directly proportional to the angular speed of newlinethe wind turbine shaft, for a particular wind speed. The terminal voltage and frequency of the newlinesquirrel cage induction generator are controlled by means of matrix converter based on fieldoriented control, to steer the turbine shaft angular speed and accordingly, control power output newlineat the wind turbine for all wind speeds. newlineThe thesis addresses dynamic models of each particular module of wind energy conversion newlinesystem: aerodynamic model, mechanical model, gearbox model, squirrel cage induction newlinegenerator model and matrix converter model and an overall dynamical model for the proposed newlinewind energy conversion system. newlineThe dynamic model of the matrix converter is applicab