基于Prony谱线估计方法的间谐波检测

传统的谐波分析方法都是基于傅立叶变换,认为只有谐波周期均为基波周期的整数倍。然而,实际存在的间谐波周期与基波周期不成整数倍关系,要正确检测出间谐波,必须以间谐波与基波周期的最小公倍数作为检测周期,因此,FFT算法无法在较短的时间内精确检测到信号中的谐波和间谐波成分。将Prony谱线估计方法应用到间谐波检测中,推导出间谐波频率、幅值和相位的计算公式。仿真验证了该算法要优于FFT算法,对间谐波和谐波的幅值、频率和相位的估计具有很高的精度。

Interharmonic Measurement Based on Prony Spectrum Line Assessment Method

All conventional harmonic analysis methods are based on Fourier transform with the assumption of all the harmonics periods being interger multiple to the fundamental wave period.However,the interharmonic periods,which really exist,are not interger multiple to the fundamental wave period.In order to measure the interharmonic correctly,it must use the least common multiple of interharmonic and fundamental wave period as measuring period.Therefore,FFT algorithm cannot accurately detect harmonics and interharmonic components in the signal during short time.Aimed to solve this problem,an interharmonic estimation method based on Prony spectrum line analysis was applied to its detection.The calculation formula of the frequency,amplitude and phase of the interharmonic was derived.The simulation results demonstrated that this method was better than FFT algorithm and high accuracy of estimation of the frequency,amplitude and phase of harmonics as well as interharmonic was achieved.