Measurement of asynchronously sampled harmonically distorted waveforms

This paper describes the algorithm for estimating frequency, amplitude and phase of fundamental component in harmonically distorted waveform. The algorithm minimizes phase difference between sine model and sampled waveform by effectively canceling out the influence of harmonic components. It uses three parameter sine fit algorithm for all phase calculations. The resulting estimates show up to two order of magnitude smaller sensitivity to harmonic distortions than four parameter sine fit algorithm.