基于LabVIEW的双馈风力发电机组在线谐波分析研究

Double-fed wind turbine harmonic analysis based on LabVIEW

针对双馈风力发电机组在并网运行时,其电力电子变流装置将向电网注入大量谐波电流的问题,将基于LabVIEW的在线谐波分析技术应用到双馈风力发电机组的谐波监测分析中。开展了针对双馈风力发电机组注入电网谐波的傅里叶分析和小波包分析,提出了将傅里叶变换与小波包变换联合使用的方法;在LabVIEW上搭建了仿真平台,对双馈风力发电机组可能存在的谐波进行了仿真分析试验。试验及研究结果表明,对于平稳信号与非平稳信号进行谐波分析时,将傅里叶变换与小波包变换联合使用,两者的效能得到明显的提高,优于单独使用傅里叶变换或小波包变换,且可更准确地获取基波和谐波的实时波形与频域特性,谐波定位更准确,为谐波补偿提供了更可靠、准确的信息。

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.