A novel technique to eliminate the effect of decaying DC component on DFT based phasor estimation

This paper describes a novel technique to eliminate the effect of decaying direct current (DC) component on DFT based phasor estimation. This technique is based on estimating the phasor of a sinusoidal wave corrupted by a DC component at an instant of time. Another phasor is estimated after half cycle from the instant of estimating the first one. The two phasors are added and a mathematical expression for the decaying DC component is derived. A phasor corresponding to the decaying DC component is calculated from this mathematical expression. The decaying DC component can be eliminated by subtracting this phasor from the phasor corresponding to a sinusoidal component corrupted by a DC component. The simulation results show the accuracy of the algorithm in calculating the fundamental phasor value regardless of the DC content in the input signal. This technique is compared to the most recent techniques for eliminating the effect of DC component on the DFT based phasor estimation methods.