Enhancement of FFT-based algorithm for voltage flicker measurement

Digital algorithms have been widely used for the measurement of voltage flicker, and the fast Fourier transform (FFT) is the most popular tool to calculate individual and equivalent voltage flicker components. In this paper the effects of system frequency deviation on the performance of FFT-based algorithms are analyzed, and an enhanced indirect demodulation algorithm is proposed to mitigate the effect. The simulation results illustrate that the proposed method can effectively improve the error caused by the system frequency deviation; besides, field test results also validate the feasibility of the virtual instrument used to implement the algorithm.