Maximum power tracking control scheme for wind generator systems

Abstract

The purpose of this work is to develop a maximum power tracking control strategy for variable speed wind turbine systems. Modern wind turbine control systems are slow, and they depend on the design parameters of the turbine and use wind and/or rotor speed measurements as control variable inputs. The dependence on the accuracy of the measurement devices makes the controller less reliable. The proposed control scheme is based on the stiff system concept and provides a fast response and a dynamic solution to the complicated aerodynamic system. This control scheme provides a response to the wind changes without the knowledge of wind speed and turbine parameters. The system consists of a permanent magnet synchronous machine (PMSM), a passive rectifier, a dc/dc boost converter, a current controlled voltage source inverter, and a microcontroller that commands the dc/dc converter to control the generator for maximum power extraction. The microcontroller will also be able to control the current output of the three-phase inverter. In this work, the aerodynamic characteristics of wind turbines and the power conversion system topology are explained. The maximum power tracking control algorithm with a variable step estimator is introduced and the modeling and simulation of the wind turbine generator system using the MATLAB/SIMULINK® software is presented and its results show, at least in principle, that the maximum power tracking algorithm developed is suitable for wind turbine generation systems.