Stability analysis of hybrid active power filter

In the paper the analysis of a three-phase hybrid active power filter stability has been presented. Configuration with a single tuned passive filter was used as an example. However, the analysis can be applied to similar configurations of hybrid filters with closed loop control. The article presents a model of the analyzed system in the frequency domain. The division of the model into two independent systems, for positive and negative components, allowed to apply the Nyquist criterion for the stability analysis in this case. As a part of the analysis, the effect of delays, control signal filter parameters, and passive filter parameters have been examined. Based on the presented stability analysis, system parameters for the experimental model of a hybrid power filter have been selected. Finally, experimental results confirming the validity of the analysis have been shown.