79 Intelligent Control of PWM Converter for Grid Integration of Variable Speed Wind Turbines

A variable-speed wind turbine has a back-to-back PWM converter consisting of a machine-side converter and a grid-side converter. Traditionally, the grid-side converter is controlled through decoupled PI control mechanisms. In this paper, power control characteristics of the grid-side converter are studied both analytically and through computer simulation. Deficiencies of the conventional control strategies are analyzed. Then, an optimal control approach is developed from a nonlinear programming point of view. An intelligent control system for the grid-side converter is developed by integrating fuzzy, adaptive, and PID control technologies, which is evaluated through a transient simulation approach. Comparisons are made between the newly developed intelligent control method and traditional PI based control mechanisms.