Double-fed wind turbine harmonic analysis based on LabVIEW

BIAN Haowei,ZHANG Jiyong,ZHANG Suxin,GUO xin
(School of Energy and Power Engineering,Yangzhou University,Yangzhou 225127,China)

Abstract: In order to solve the problem of a large number of harmonic current injected into the power grid by the power electronic converters devices when doublefed wind turbine combined to the grid，the LabVIEWbased online harmonic analysis technology was applied to the harmonics monitoring and analysis of the doublyfed wind turbine.After the analysis of the harmonics injected by the doublyfed wind turbine,a method was presented to combine the Fourier transform and wavelet packet transform.The simulation platform was built based on LabVIEW.The simulation test was evaluated on the harmonic current which may exist in doublyfed wind turbine.The experimental results show that, the harmonic analysis for stationary signals and nonstationary signals,the combined use of Fourier transform and wavelet packet transform will improve both performance. The result is better than the separate use of the Fourier transform or wavelet packet transform.The combined use of them can be more accurate access to realtime waveform and frequency domain characteristics of the fundamental and harmonic, more accurate positioning of harmonic. It can provide more reliable and accurate information for harmonic compensation.
Key words: LabVIEW; Fourier transform; wavelet packet transform; doublefed wind turbine; harmonic analysis