一种基于综合DFT和Prony算法的谐波与间谐波分析方法

A harmonic and interharmonic analysis method based on integrated DFT and Prony algorithm

针对传统频域谐波测量方法存在的时域分析局限性,提出了一种综合频域(FFT)和时域(Prony)的谐波与间谐波分析方法。首先对谐波与间谐波信号进行离散傅里叶变换(DFT),获取信号的频谱范围,据此选择Prony算法的采样率,并依据信噪比选取Prony算法的模型阶数。然后基于Prony算法得到信号中各谐波与间谐波分量的频率、幅值、相位和衰减因子。最后基于能量系数筛选得到主导次谐波与间谐波分量,通过基于Prony的数据重构得到主导次分量的时域变化趋势。实测数据分析表明,所提分析方法可以准确得到主导次谐波与间谐波分量的时域指标和变化趋势,实用性较强,为事故准确溯源分析提供了有效手段。

Aiming at the limitation of traditional frequency domain harmonic detection method in time domain analysis,a harmonic and interharmonic analysis method based on frequency domain and time domain is proposed.First,the Discrete Fourier Transform(DFT)is applied to the harmonic and interharmonic signals to obtain the spectrum range of the signal.Thus,the sampling rate of Prony algorithm is selected according to the spectrum range,and the model order of Prony algorithm is selected according to the signal-to-noise ratio.Then,the frequency,amplitude,phase and attenuation factor of each harmonic and interharmonic component in the signal are obtained based on Prony algorithm.Finally,the dominant harmonics and interharmonics components are selected based on the energy coefficient,and the temporal variation trend of the dominant harmonics and interharmonics components is obtained through the data reconstruction based on Prony algorithm.The analysis of measured data shows that the proposed analysis method can accurately obtain the time-domain index and change trend of dominant harmonics and interharmonics components,and has strong practicability,which provides an effective means for accurate accident traceability analysis.