Experimental study on the impact of turbulent motions on the output of small wind turbines

Recent studies on high-Reynolds-number turbulence in the atmospheric surface layer, with shear Reynolds numbers above 106, indicate that turbulent motions contribute significantly to the transport of momentum and scalars. This implies that turbulent motions must be accounted for in wind turbine power output prediction models. Based on the field experiments, the influence of turbulent motions on the output of small-scale wind turbine was analyzed. The results show that the stream-wise wind speed is strongly and positively correlated with output voltage, with a correlation coefficient of 0.65–0.9, whereas vertical wind speed exhibits a weak negative correlation of −0.09 to 0 and suppresses power generation. Furthermore, the mean and standard deviation of output voltage increase approximately linearly with those of the stream-wise wind speed. This paper presents the parameter models for predicting the mean and standard deviation of output voltage. In the low-frequency band, the voltage power spectrum slopes −1.3 to −1.5, flatter than the wind speed spectrum's −1.67. As the mean wind speed increases, the coherence between the wind speed and the output voltage in the frequency domain is significantly enhanced.