Moving average-based mitigation of exponentially decaying DC components

Exponentially decaying DC components are normally found in current signals during a fault in an electric power system. As these components generally decrease the precision of phasor estimation techniques, they must be filtered out. Thus, this paper proposes an alternative approach to mitigate exponentially decaying DC components. Firstly, the damping factor of the input signal is estimated using its moving average. Then, based on the symmetry of the sinusoidal signal, the value of the exponentially decaying DC component is calculated and subtracted. Tests were conducted with simulated signals, comparing the proposed approach with the state-of-the-art literature. Additionally, all the techniques were embedded in a microcontroller to validate their performances in hardware. Overall, the proposed approach presented the best software performance, compatible with hardware embedded applications in a low-cost microcontroller, proving to be an effective methodology to mitigate the DC offset.