Considerations on signal processing for power systems in the context of Smart Grids

The trend towards the implementation of Smart Grids results in a higher complexity of power signals and their voltage quality implication. As a consequence, for this kind of environment, the traditional harmonic distortion analysis that assumes a balanced and steady-state condition is no longer sufficient to provide accurate information on the state of the system. For this reason, more advanced signal processing techniques are of vital importance. These should be able to track time-varying harmonics both in time and frequency domain. This paper uses Filter Banks and Sliding-Window Recursive-DFT (SWR-DFT) to track time-varying harmonics when a converter is connected to the grid. The experiment shows methods to extract time-varying harmonics, and lead to a better understanding of its time-varying nature.