WIDE RANGE PARAMETER MEASUREMENT OF SINUSOIDAL SIGNALS

Wu Jiekang

   A high-accuracy, wide-range parameter measurement method basing on a numerical differentiation and central Lagrange interpolation is proposed in this paper. The 2^nd order differentiation is used in frequency estimation, and the 3^rd and 4^th order differentiation is employed in amplitude and phase measurement. The proposed algorithm needs at most half a cycle for parameter measurement, which is much less than other algorithms due to the application of numerical differentiation. With unknown parameters, the frequency is measured with an error of 0.001 % over 2 Hz to 3500 Hz, and amplitude is estimated with 0.01 % over 3 V to 160 V and at 2 % over 160 V to 220 V. The phase is measured with an error error of 0.001 % over 10 to 360, and at most 3 % when the frequency is less than 5 Hz and the amplitude is less than 3 V. A study example is given to illustrate its parameter measurement, and Matlab software is applied to validate the proposed algorithm.

Keywords: parameter measurement, sinusoidal signal, numerical differentiation, Lagrange interpolation

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