Exact Harmonics/Interharmonics Calculation Using Adaptive Window Width

An accurate, simple, and practical numerical method for exact calculation of harmonics/interharmonics using adaptive window width is presented in this paper. The proposed method adaptively adjusts the window width based on correlation calculation, thus completely eliminating or significantly reducing the unacceptable spectral leakage errors in the frequency domain caused by truncation of the time-domain signal. The iterative algorithm does not require any knowledge about the system frequency and the interharmonic constituents; the only parameter needed is the signal sequence obtained by sampling the analog signal at equidistant sampling interval. Various case studies using simulation data, experimental data and the real world data show that the adaptive algorithm provides an ideal numerical solution to the problem of spectral leakage encountered in harmonics and interharmonics detection and analysis.