Control Performance Analysis of Feedforward and Maximum Peak Power Tracking for Small-and Medium-Sized Fixed Pitch Wind Turbines

As the wind has become one of the fastest growing renewable energy sources, the key issue of wind energy conversion systems is how to efficiently operate the wind turbines in a wide range of wind speeds. In this paper where small- and medium-sized fixed pitch wind turbines are focused, a control performance analysis of the feedforward and maximum peak power tracking (MPPT) to maximize the power of the turbines while operating in their below rated power and to limit the power while operating in their above rated power is presented. The algorithms were implemented on a low cost digital signal controller (DSC) board and tested with a developed real-time wind turbine simulator, consisting of an induction motor driven by a torque control inverter, and computer interface for data acquisition. The experimental results show that the feedforward performs more satisfactorily when compared to the MPPT and has better performance indices in overall operating conditions. However, the feedforward causes power oscillation in the above rated power and needs wind turbine parameters as a control reference, but those parameters are not necessary in the MPPT, which exhibits an attractive feature