风电汇集地区次/超同步谐波分析方法研究

STUDY ON SUB/SUPER-SYNCHRONOUS HARMONIC DETECTION METHOD IN DENSE WIND POWER AREAS

对频域特性良好的Blackman窗和4项3阶Nuttall窗做卷积运算得到混合卷积窗函数,并推导出三谱线插值修正公式。基于全相傅里叶变换(apFFT)的相位不变性,利用峰值频点附近最大与次大幅度谱比值,提出Hanning双窗apFFT双谱线插值参数分析算法。因加混合截断窗插值FFT的频率与幅值参数分析误差较低,apFFT可以精准获得相位谱信息,由此提出一种组合型次/超同步谐波参数分析算法。仿真对比实验证明,所提算法在稳态与非稳态下均能有效且精准地实现谐波参数分析。最后,将该算法应用于风电并网模型风电场电流频谱分析及新疆哈密地区次/超同步谐波分析,验证其有效性。

A convolution operation is performed on the Blackman window and the 4 terms 3 order Nuttall window with good frequency domain characteristics to obtain a hybrid-convolution window function,the rectification formula of the triple-spectrum-line is proposed based on that window function. According to the phase invariance of apFFT,the double-spectral-line correction harmonic analysis algorithm based on Hanning double window apFFT is deduced by using the ratio of the main spectral line and side spectral line amplitudes near the theory frequency point. A combinatorial optimization algorithm is proposed,which uses the first method to detect amplitude and frequency parameters,and uses the second method to detect phase parameter. The simulation results indicated that the algorithm can accurately achieve harmonic parameters estimation,and suppress the interference between the spectrums. Finally,the combinatorial optimization algorithm is applied to the current spectrum analysis of wind farms of the wind power generation interconnected model and sub/super-synchronous harmonic detection in Hami,and the effectiveness of the algorithm is verified.