CAJ | 학술논문

分析了初始相位敏感性产生的根源及影响初始相位敏感性大小的因素，并提出减小初始相位敏感性的方法以提高加窗离散傅里叶变换(DFT)算法的稳定性。理论分析和数值结果表明：初始相位的随机性会引入谐波幅值计算误差，但并不是所有的加窗DFT算法谐波分析都需要考虑相位敏感性；频率偏差一定条件下，初始相位敏感性大小由窗函数的旁瓣峰值电平决定，旁瓣峰值电平越低，初始相位敏感性越小，旁瓣峰值电平-58 dB可以作为衡量窗函数是否需要考虑初始相位敏感性的参考值。实际工程中，可以通过增加采样长度的方法减小初始相位敏感性的影响。
분석료초시상위민감성산생적근원급영향초시상위민감성대소적인소，병제출감소초시상위민감성적방법이제고가창리산부리협변환(DFT)산법적은정성。이론분석화수치결과표명：초시상위적수궤성회인입해파폭치계산오차，단병불시소유적가창DFT산법해파분석도수요고필상위민감성；빈솔편차일정조건하，초시상위민감성대소유창함수적방판봉치전평결정，방판봉치전평월저，초시상위민감성월소，방판봉치전평-58 dB가이작위형량창함수시부수요고필초시상위민감성적삼고치。실제공정중，가이통과증가채양장도적방법감소초시상위민감성적영향。
The origin of initial-phase sensitivity and the main factors influencing the level of initial-phase sensitivity are analyzed,then the method of reducing initial-phase sensitivity is proposed to increase the stability of the windowed discrete Fourier transform (DFT) algorithm.Theoretical analysis and numerical results indicate that randomness of initial-phase will bring about harmonic amplitude calculation errors.However,not every windowed DFT algorithm needs consideration of the initial-phase sensitivity.Under a definite frequency deviation,the level of initial-phase sensitivity is determined by the sidelobe peak level of window functions.The lower the sidelobe peak level is,the smaller the initial-phase sensitivity will be.The sidelobe peak level -58 dB can be a reference to determining whether the initial-phase sensitivity needs to be considered in the window functions.In practical engineering,the method of increasing the length of time record can be used to reduce the influence of initial-phase sensitivity.