电能质量监测中频谱泄露检测方法研究

Research on Detection Method of Spectrum Leakage in Power Quality Monitoring

为了提高电能质量算法的精确度,需要检测傅里叶变换(FFT)时的频谱泄露程度,尽可能地抑制频谱泄露现象。详细分析了频谱泄露的机理,在此基础上提出了一种基于调制波的频谱泄露检测方法,在源信号上叠加调制波,根据连续十周波电压测量值,计算出波动频率下的频谱泄露系数,从而判断信号的频谱泄露情况。使用该方法对比分析了通过两种不同加窗方式进行FFT的结果,实验结果验证了频谱泄露系数及其约束条件的可行性,该检测方法简单易操作,能够有效地检测频谱泄露现象,为检测电能质量监测终端的电压计算方法提供了新思路。

In order to improve the accuracy of the power quality algorithm,it needs to detect the degree of spectrum leakage of the Fourier transform(FFT)and suppress the spectrum leakage.The mechanism of spectrum leakage is analyzed in detail and a detection method of spectrum leakage based on modulated wave is proposed.The modulated wave is superimposed on the source signal,and the spectrum leakage coefficient of the fluctuating frequency is calculated according to the continuous ten-cycle voltage measurement value,thereby judging the spectrum leakage of the signal.By comparing and analyzing two different windowing methods,the experimental results verify the feasibility of the spectrum leakage coefficient and its constraints.This detection method is easy to operate and can effectively detect the spectrum leakage,and it provides a new idea for testing the voltage calculation method of power quality monitoring terminal.