Time-frequency Analysis of Output Power of Wind Turbine Based on Wavelet Transform

Instability is one of shortcomings for wind power. Along with the increasing of the number of wind farms, power instability also increased. The fluctuation of wind power will cause the variation of voltage in access point .The impact of this fluctuation to power grid is more and more bigger. To reduce this impact, we should smooth and filter the output power. Therefore, a detailed analysis of the characteristics of output power is very necessary. This paper starts with the study of stationary principle. Then study second-time-scale output power. We find the power is non-stationary random signal sequence. This sequence does not have the concept of spectrum, so we choose wavelet analysis, which is commonly used in non-stationary random signal analysis, to do the time-frequency analysis of the output power. Keywords-output power of wind turbine, stationary test, wavelet analysis