abstract

• Cascaded multilevel converters based on medium-frequency (MF) AC-links have been proposed as alternatives to the traditional low-voltage inverter, which uses a bulky low-frequency transformer step-up voltage to medium voltage (MV) levels. In this paper, a three-phase cascaded DC-AC-AC converter with AC-link for medium-voltage applications is proposed. Three stages integrate each DC-AC-AC converter (cell): a MF square voltage generator; a MF transformer with four windings; and an AC-AC converter. Then, k DC-AC-AC converters are cascaded to generate the multilevel topology. This converter’s topological structure avoids the per-phase imbalance; this simplifies the control and reduces the problem only to solve the per-cell unbalance. Two sets of simulations were performed to verify the converter’s operation (off-grid and grid-connected modes). Finally, the papers present two reduced preliminary laboratory prototypes, one validating the cascaded configuration and the other validating the three-phase configuration. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

authors

• Barrios M.A.
• Cárdenas Galindo Víctor Manuel
• Guerrero J.M.
• Sandoval J.M.

publication date

• 2021-01-01

published in

• Electronics (Switzerland)  Journal

keywords

• AC-AC converter; AC-link; Cascaded converter; Matrix converter; Medium-frequency magnetic link; Multilevel converter; Photovoltaic

Digital Object Identifier (DOI)

• 10.3390/electronics10040409

PubMed ID

start page

• 1

end page

• 21

volume

• 10

issue

• 4