New Spectrum Leakage Correction Algorithm for Frequency Estimation of Power System Signals

A new algorithm for the estimation of the frequency of single-tone signals is presented in this paper. The algorithm works in the frequency domain and is based on best fitting a theoretical spectrum of a single-tone signal that is windowed using a rectangular window on the spectrum of the sampled signal. Using this iterative process, the algorithm compensates the spectrum leakage caused by incoherent sampling and a finite number of samples. Due to leakage compensation, the algorithm provides accurate estimates of the signal´s frequency, amplitude, and phase. The influence of noise and harmonic and interharmonic distortions on the proposed algorithm was investigated and is reported here. The algorithm´s performance was compared with several other frequency-estimation algorithms (mostly those working in the frequency domain). Since the algorithm is intended for power quality measurements (although it is not limited to this application), it was also tested on signals measured in a single-phase power system.