基于Prony算法的电压闪变检测方法研究

A novel method based on Prony analysis for voltage flicker assessment

基于常用电压闪变测量方法的调查研究,在电压闪变的在线检测和分析中引入了Prony算法。首先由输入信号序列构造了一个样本矩阵,再利用SVD算法对样本矩阵进行奇异值分解,得到了样本矩阵的有效秩,然后根据最小二乘法估算出信号各频率分量的特征参数,最后利用解调制原理准确地得到了信号的包络。针对有谐波源的电压闪变问题,对包络解调进行了修正,从而保证在有谐波源情况下也能有效获取电压闪变信号的包络。仿真实验结果表明,该方法具有高分辨率、高精度等优点,并验证了其准确性和有效性。

An efficient method, based on a modified Prony technique to track the voltage flicker was presented. Firstly, the Prony technique was used to extract the magnitudes, frequencies, and phase angles of all frequency components of the voltage flicker signal. Then voltage flicker signal was reconstructed as linear combination of sinusoids. Finally, the envelope of the voltage flicker signal was obtained by the principle of envelop detection. Considering the effect of harmonics on voltage flicker measurements, modification was introduced to avoid the effect and improve the precision, by means of removing the harmonic components from the reconstructed signal, and adding the magnitudes of harmonic components to the envelope of the reconstructed signal without harmonic components. Simulation results show that, the method has many advantages such as high identification, high precision. Thereby effectiveness of the modified Prony technique for flicker analysis is verified.