Analysis and control of a variable speed wind turbine drive system dynamics

Wind turbulence causes abrupt variation in the power generation and delivery to the grid in the wind energy conversion systems. Most of the system parameters like tip-speed ratio, shaft dampness and dc-link voltage vary during the operation of the variable speed wind turbine drive system at different values of wind velocity. The wind speed turbulence excites the low frequency spectrum of the system. This paper presents analysis on the plant dynamics aspects at low frequencies and control of a wind turbine system operating in variable speed mode using back-to-back converter. The non-minimum phase dynamics of the system is discussed. The dc-link voltage tracking is analyzed.