Dynamic capacitor — VAR and harmonic compensation without inverters

Dynamic Capacitor (D-CAP) is able to provide both dynamic VAR injection and active harmonic filtering in one single integrated unit using a direct AC converter topology interfaced with a power factor correction or a VAR capacitor. Previous papers have shown the effectiveness, higher reliability and lower cost of the D-CAP when compared with commercial inverter-based solutions. However, these papers have focused primarily on the buck D-CAP. This paper will extend the discussions to the boost- and buck-boost topologies as well. Analytical and numerical expressions are derived for these three topologies, and comparisons are made in terms of performance and component ratings.