Since the global warming is a very serious issue, renewal energy sources is now intensively under research and development to substitute fossil fuel energy. Wind power generation is one of the promising options to contribute to this purpose. In 2009, Port and Airport Research Institute built a small wind power generation demonstration plant to monitor its long term performance. In the plant, wind has been measured and recorded with two different tools of an ultrasonic anemometer and a cup anemometer as well as wind power generation.
　Wind data are fundamental and indispensable information for the design of wind power facilities. Cup anemometers are classical tools, but still now widely used practically for measuring wind. However, it should be noted that the cup anemometer has a mechanical rotation system which may cause its poor response behavior in the fluctuating wind.
　In this report, frequency response performance of cup anemometer is studied. A linearized model for the cup anemometer is proposed for describing its power attenuation in the high frequency dynamics. The model is verified by numerical simulation and compared with real field wind data using spectrum analysis. A simple compensation method of cup anemometer is also proposed to improve its dynamic performance.