CAJ | 학술논문

针对快速傅里叶变换(FFT)在非同步采样下存在检测精度低的问题，根据Nuttall窗的旁瓣特性以及FFT后信号的谱线特点，提出一种基于Nuttall窗三峰插值的电力系统谐波检测算法。用曲线拟合得到修正公式，并基于修正公式进行了Matlab仿真。仿真结果表明，在同等条件下，该算法处理信号的幅值修正相对误差小于2.44×10-5%，相位修正相对误差小于0.004%。该算法相对于单峰及双峰插值精度更高，相比于五点、九点算法，所提算法可以提前得到修正公式无需对离散序列重新组合。
침대쾌속부리협변환(FFT)재비동보채양하존재검측정도저적문제，근거Nuttall창적방판특성이급FFT후신호적보선특점，제출일충기우Nuttall창삼봉삽치적전력계통해파검측산법。용곡선의합득도수정공식，병기우수정공식진행료Matlab방진。방진결과표명，재동등조건하，해산법처리신호적폭치수정상대오차소우2.44×10-5%，상위수정상대오차소우0.004%。해산법상대우단봉급쌍봉삽치정도경고，상비우오점、구점산법，소제산법가이제전득도수정공식무수대리산서렬중신조합。
It is difficult to perform accurate harmonic analysis with Fast Fourier Transform (FFT) under the unsynchronized sampling conditions. According to the components of the sidelobe characteristic of the Nuttall window and signal discrete spectrum characteristic by FFT, an approach for power harmonic analysis based on Nuttall window and the triple-spectral-line Nuttall window interpolation is proposed. The modified formula is obtained by using polynomial fitting method and Matlab simulation of the power harmonics is made based on it. The simulation results indicate that under the same condition, the amplitude correction errors are less than 2.44×10-5%, as well as that of the calculation phases no more than 0.004%. It has higher analysis accuracy comparing with single-spectral-line interpolation and double-spectral-line interpolation. Compared to the five points' and the nine points' algorithm, the application rectification formulas is obtained without the need to get the spectral sequence.