Improved Analytic Energy Operator and Novel Three-Spectral Line Interpolation DFT Method for Parameter Estimation of Voltage Flicker

An improved analytical energy operator (IAEO) and novel three-spectral line interpolation discrete Fourier method is proposed in this article to estimate voltage flicker parameter. First, the analytic energy operator is improved based on Taylor series to better extract the amplitude and frequency features of voltage flicker envelope signal, and simplify the envelope extraction formula to avoid the square root operation. Then, a novel three-spectral line interpolation discrete Fourier transform (DFT) algorithm is constructed by using Kaiser window and Blackman-Harris mutual convolution, and the amplitude and frequency correction formulas of voltage flicker are derived based on the novel three-spectral line interpolation DFT. Finally, the voltage flicker parameter estimation is realized on the virtual instrument based on the proposed method. The applicability and accuracy of the IAEO and novel three-spectral line interpolation DFT method for parameter estimation of voltage flicker are verified by a series of simulations and experiments.