Analysis, Design and Simulation of Single-Phase Isolated Improved Trans-ZS AC-AC Converter

In the following study a single-phase isolated improved trans-ZS AC-AC converter is analyzed, designed and simulated. This converter is from Z-source family and contains their specific advantages such as inclusive variety of buck-boost output voltage in in-phase or out-of-phase manner. Also, a high frequency transformer (HFT) is utilized in its structure in order to electrical insulation. Therefore, in some applications, for example dynamic voltage restorers (DVRs), there are no need for bulky and lossy grid-coupling transformers. Furthermore, a safe commutation method has been utilized which eliminates the voltage spikes upon power switches. One of the distinct tasks of this paper is to bring all three-winding transformer's conversion ratios into computation as well as extracting all the governing relations of the structure in in-phase and out-of-phase operational states. Finally, the simulation using power systems computer-aided design (PSCAD) software is conducted to confirm the analysis.