Harmonic component estimation through DFSWT for active power filter applications

Nowadays, power quality monitoring is a very important subject. The growing utilization of nonlinear loads such as rectifiers considerably distorts the shape of current and voltage signals affecting the power quality of the grid. Therefore, harmonic estimation and compensation are important tasks for improving power quality indexes in electric systems. In this work, the feasibility of using the discrete Fourier square-wave transform (DFSWT) as a fast processing engine, with low power consumption, for online harmonic component estimation is assessed. From obtained results, the current harmonic components demanded by the nonlinear loads were properly identified through DFSWT and compensated utilizing a shunt active power filter (S-APF) in all treated cases, obtaining a well-shaped sinusoidal current signal in the grid front-end.