Dynamic Modeling, Simulation and Control of the Power Conditioning System for a Variable-Speed Wind-Turbine

This work presents the modeling, simulation and control of the power conditioning system of a grid-connected variable-speed wind-turbine. The power conditioning system is composed by two sinusoidal-pulse-with-modulated (SPWM) voltage source converters (VSC) interconnected by a dc-link. The generator-side converter is controlled to extract the maximum power for a given wind speed. The grid-side converter is controlled so that the energy is exchanged with unity displacement factor. A discrete control structure based in three control loops has been use for the grid-side converter: a first control loop is used for the correction of the displacement factor in order to obtain a current in counter-phase with the grid (for grid injection); the control of the peak current that is injected to the grid, and the control that regulates the dc-link voltage in order to allow that all the current extracted from the wind turbine is to be injected to the grid, The dynamic model of three-phase VSC is developed at synchronous reference frame with grid voltage, which permits the analisys of the performance of the proposed control with long simulation periods. Finally, the simulated results are compared with a prototype of 1.5 kW, where the wind turbine is modeled by two squirrel-cage induction motors mechanically coupled. Copyright (C) 2008 Praise Worthy Prize S.r.l - All rights reserved.