Accuracy of a DFT phasor estimator at off-nominal frequency in either steady state or transient conditions

The paper analyzes the effect of harmonics and wideband noise on the accuracy of the phasor estimator provided by the Discrete Fourier Transform (DFT) at off-nominal frequency when a decaying dc offset component is either absent or present in the acquired signal. The analysis, performed through both computer simulations and experimental results, shows the high sensitivity to transient conditions of the DFT-based phasor estimator algorithm.