Nonlinear Predictive Power Controller with Constraint for a Wind Turbine System

The wind turbine models are hardly nonlinear with regards to rotational speed versus wind speed. Thus standard control techniques do not provide acceptable performances for controlling the output power over the operational range. This paper proposes a nonlinear predictive power controller adapted for a variable speed vertical axis wind turbine. This controller needs to minimize a quadratic criterion, which generally requires a high processing time. To overcome this shortcoming, an internal model control (IMC) optimization is introduced. Simulation results using a proven model of a 100 kW wind turbine are presented to demonstrate the effectiveness of the nonlinear predictive power controller for changes in the reference as well as for disturbances like changes in the wind speed