Digital algorithms for parameter estimation of multiple signals using numerical differentiation

A novel algorithm for amplitude and phase estimation of the multi-component signals is presented in this paper. The proposed algorithm is based on numerical differentiation and central Lagrange interpolation, and needs 1 signal sample with 7 points and 1 computation process. With any frequency value of component 1, 2 and 3 of the signal over 1 Hz to 100 kHz, the amplitude and phase angle of the signal are all estimated at an accuracy of higher than 0.1% with the amplitudes of the component 1,2 and 3 varying from 1 V to 200 V and the phase angle of the component 1, 2 and 3 varying from 0 to 360. Spending at most half cycle for parameter estimation of the multi-component, so that the proposed algorithm is adaptive to any intelligent measurement and control. A testing example is given to illustrate the proposed algorithm, with the simulation is carried out in Matlab software.