Influences of the anti-aliasing filter damping factor in an active power filtering environment

This paper presents the performance influences of the damping factor of a second order anti-aliasing filter in an active power filtering (APF) environment. For the studied plant, due to the significative changes in the system response, it is shown that is very important the appropriated choice of this parameter. To analyze the differences among responses, when the anti-aliasing filter damping factor is varied, the APF systems are implemented using a proportional integral (PI) controller. The paper shows the low-pass filtering effect for two APF´s topologies: The first topology uses a mono-phase shunt Voltage Source Inverter (VSI) to compensate a non-linear inductive/capacitive load; The second one uses a three-phase/three-legs active power filter, considering a three-phase rectified inductive load. At the end of the text, simulation results are presented in order to compare the performance of using different analog filter damping factors for the two APF systems, verifying their responses under high harmonic content.