关于电力系统FFT谐波检测存在问题的研究

Study on problems about detecting harmonic based on FFT in power system

快速傅立叶变换FFT(Fast fourier transform)是应用最广泛的一种谐波检测方法,但利用FFT进行谐波测量时存在较大的误差,影响谐波分析结果准确性,无法直接应用于电力系统谐波分析中。对使用FFT进行电力系统谐波检测时存在的问题从产生原因和改进方法两个方面进行了详细分析和总结。分析了目前已有的改善这些问题的新途径和新方法的优缺点,表明这些方法在不同方面提高了信号的分析精度和谐波测量参数的可信度。最后对预防、补偿电力系统FFT谐波检测存在问题的措施进行了总结并提出了看法。

FFT is the most comprehensive method in harmonic measurement fields, but there are obvious errors in harmonic analysis using FFT algorithm, which affects the accuracy of measurement results. So it cant be directly applied to harmonic analysis in power system. The paper analyses and summarizes problems brought by using FFT method to analyze harmonic of power system with cause and improved methods. It analyses the advantages and disadvantages of different measures used as ways and means for compensating those problems, which demonstrates that the analysis accuracy of the signal and the credible degree of the measurement parameters are further improved in different aspects. In the end, the paper summarizes precautionary and improved measurements.