High-Frequency Isolated AC-DC-AC Interleaved Converter for Power Quality Applications

This paper presents a single-phase ac-dc-ac converter with high-frequency isolation, which employs the interleaved technique. The proposed converter is suitable for power quality applications, such as dynamic voltage restorers, uninterruptable power supplies, and voltage regulators. The modeling of power flow is presented, focusing on the minimization of the transformer current. This analysis is improved by the introduction of the actuators type concept, which ensures reduced current through the transformer. Moreover, the effective longitudinal inductance of the series association of the boost inductor and two interphase transformers is determined. The soft-switching regions are also obtained as well as their dependency on the phase-shift angle. The proposed converter is compared with one indirect ac-dc-ac topology, which uses the dual active bridge converter as the isolation stage. Experimental results are obtained to show that the proposed converter is able to provide power factor correction, mitigate voltage sags, and regulate the output voltage.