五项最小旁瓣窗插值方法电力谐波参数估计

摘要

为解决快速傅里叶变换方法在实际应用中遇到的频谱泄漏和栅栏效应问题,并提高其测量的准确度,提出了一种加窗插值快速傅里叶变换方法.选用五项最小旁瓣窗对采样数据加权,以抑制由于非同步采样导致的频谱泄漏;采用基于多项式拟合的插值方法消除栅栏效应.通过Matlab仿真软件,在基波频率波动和噪声条件下,比较了五项最小旁瓣窗插值方法与既有电力谐波参数估计方法,有效验证了五项最小旁瓣窗插值方法的准确性.通过试验环境下的电力谐波测量,进一步验证了五项最小旁瓣窗插值方法的有效性.仿真分析和试验研究结果表明,五项最小旁瓣窗插值方法有效解决了频谱泄漏和栅栏效应问题,能够准确提取包括弱谐波分量在内的各次谐波.%To overcome the problems of spectral leakage and fence effect in application of the fast Fourier transform (FFT)method and to improve the accuracy of the harmonic measurement,a windowed interpolation FFT method is proposed.The 5-term minimize sidelobe window is adopted for weighting the sampling data to suppress spectral leakage caused by asynchronous sampling;then,the interpolation algorithm based on polynomial fitting is employed to eliminate fence effect.Through Matlab simulation software,under the conditions of fundamental frequency fluctuation and noises,the 5-term minimum sidelobe window interpolation method and existed power harmonic parameter estimation method are compared;the accuracy of the method proposed is effectively verified.Through the electric power harmonic measurement under test environment,the effectiveness of the method proposed is verified in further.The results of simulation analysis and experimental research indicate that the interpolation method proposed effectively overcome the problems of spectral leakage and fence effect,it precisely extracts all the harmonics,including the weak components.