This paper presents a new simple control strategy for direct driven PMSG wind turbines, using no wind speed sensor. It is shown that the fluctuation in output power, not only exists at below the rated wind speed, but also appears in above the rated speed region. Therefore, it employs power smoothing strategies within a wide range of wind speed and provides soft performance of pitch angle system for above the rated speed range. In previous studies, power smoothing is mainly limited to the wind speeds below the rated value, whereas, in this paper all operating speed range of the turbine, including wind speeds above the rated value, is considered. Fluctuation in the output power for above the rated speed is analysed and it is shown that there is a significant level of fluctuation in the output power. Soa new strategy is proposed to have more power smoothing as well as having soft performance of pitch angle system for above the rated speed region. Performance of the proposed strategy is evaluated by MATLAB/ Simulink simulations and its validity and effectiveness are verified.
