Estimation of frequency, amplitude and phase of sinusoidal signals

An algorithm for the fundamental frequency, amplitude and phase of sinusoidal signals with a wide range using numerical differentiation and central Lagrange interpolation is presented in this paper. The sample consequences and its multi-order differentiation is employed for estimation computation. The proposed algorithm is adaptive to any sinusoidal signals with its frequency varying from 1 Hz to 2 kHz, its amplitude varying from 0 V to 20 V, and its phase varying from 0 to 360. The proposed algorithm for frequency estimation needs in at most 1 cycle, with an accuracy of more than 0.001%. An example for test study is simulated in Matlab software with satisfactory results for estimation of fundamental frequency, amplitude and phase.