An Analytical Study of a Grid Connected Direct Drive Permanent Magnet Generator Wind Turbine: Modeling and Simulation

Abstract

Wind is clean, free and a readily available energy source. Around the world, every day, wind turbines are capturing the wind’s power and converting it to electricity. There is considerable interest in wind power as a contributor to reducing our dependence on fossil fuel power. The number of wind turbines is growing rapidly at a rate of 29% per year. Off-shore wind turbines produce large amounts of power because of powerful ocean winds. Within the last few years, several wind turbine manufacturers have offered off-shore wind turbines with direct drive permanent magnet generators (PMG) and electronic power converters to tie-in to the electric power grid. As opposed to previous designs, the direct drive PMG eliminates the high speed gearbox. The focus of this paper is to provide an analytical study of a grid connected off-shore direct drive PMG wind turbine. The topics to be studied include the mathematical model from the moving air cylinder to the grid, the power as a function of wind speed and temperature, converter power electronics for optimal performance and wind turbine controls. Matlab is used to implement the mathematical model for analysis and simulation models using Simulink yield dynamic analyses of the wind turbine with varying wind speeds, operation of the converter and other real situations.