On cup anemometers signal processing for better measurements and maintenance

Alvaro RAMOS-CENZANO, Mikel OGUETA-GUTIERREZ, Santiago PINDADO
2019
The aerodynamics of rotatory elements is an extremely interesting topic that has brought attention of many researchers since the early works by Ludwig Prandtl. A clear example of rotational aerodynamics is the classic cup anemometer. In this research, anemometers equipped with optoelectronic output signal generators based on slotted wheels have been tested, their output signals being studied. The analysis of the output signal of the classic cup anemometer has a great relevance in the correct
more » ... e in the correct measurement of the wind speed. This correct analysis can help understand non-steady phenomena of the wind such as turbulence, optimize their maintenance, and also improve the study of the appropriate manufacture of the anemometers. Slight deviations on cup anemometer wind speed measurements may lead to non-optimal policies in wind turbine\'s control, decreasing the economic revenue of the corresponding wind power plant. These deviations may be caused by two main different problems, among others. On the one hand, the processing method used to extract the rotation/output frequency if the sensor and, on the other hand, turbulence of the flow and measurement errors present in the slotted wheel of the opto-electronic output signal generator of the anemometer. Two different processing methods to extract the aforementioned output frequency have been tested, namely the Fast Fourier Transform (FFT) and the counting pulses method (CP). These methods have been tested for different sampling frequencies and sampling time. The influence of the frequency is significant for both methods, but CP has been observed to have smaller residuals, especially at high sampling frequencies. The residuals have been observed to reach a constant value for both processing methods after a certain in value of the sampling frequency has been researched. Regarding sampling times, both methods decrease the residuals when the sampling time is increased, but the trend is more significant for CP. Turbulence and other errors affect the signature (the train of pulses [...]
doi:10.13009/eucass2019-879 fatcat:7ehsoinauvdkjnlvgyhylbzl44