LPV Control of a DFIG-Based Small Vertical Axis Wind Turbine: A Comparison Study with H∞ and PID Control

This paper presents the active power control of a doubly fed induction generator (DFIG) –based vertical axis wind turbine. The most important task of a wind turbine is to maximize the capture of available wind energy at a given time. The flexible and variable speed operation nature of DFIGs gives small vertical axis wind turbines the advantage of maximum energy capture during operation in urban areas where we expect fluctuating wind speeds and turbulent flows. We conduct a comparative study of linear parameter varying (LPV) control, classical PID control and H ∞ control using mu-synthesis of a DFIG. The outer hierarchical loop of the control structure employs PID control which is effective for the slow turbine dynamics and the three proposed controllers are compared for the inner fast current loop. The study shows that the LPV controller results in the best performance for the used wind speed while PID control results in the worst performance.