162560 20251017144608.0 doi 10.1109/ACCESS.2025.3601207 sideral 145094 ART-2025-145094 eng Cervero, David A Modular Solid-State Transformer for 3 kV DC Grids: Design, Topology, and Performance Evaluation 2025 Access copy available to the general public Unrestricted The growing emergence of Distributed Energy Resources (DER) that operate natively in dc challenges the traditional logic of unidirectional power flow and the exclusive use of ac in distribution systems due to inefficiency and control problems. dc microgrids are seen as a promising alternative to address these challenges, and Solid-State Transformers (SSTs) could be a feasible solution to enable the development of such controllable hybrid dc/ac grids. This paper presents the design, modular topology, and experimental validation of a 150 kVA SiC-based SST. This SST follows a four-module input-parallel, output-series configuration, enabling the creation of a 3 kV MV dc microgrid from the LV ac electrical grid, allowing intrinsic voltage balancing among modules, straightforward scalability in both voltage and power, and easier maintenance. Each two-stage module, in turn, consists of an active front-end and an isolated dc/dc, which is composed of a dual full-bridge driving a series CLLC resonant tank at 88-90 kHz. Laboratory and field tests demonstrate continuous dc voltage regulation in a range from 1.2 kV to 3 kV, black-start capability and support of the ac grid through reactive power. The prototype achieves a power conversion efficiency of 96.4 % under nominal conditions while transferring 151.6 kW, with line current THD remaining below 1.8 %. The SST, along with the constructed MV dc microgrids, addresses the lack of real demonstrators that can validate the benefits of dc integration. info:eu-repo/grantAgreement/EC/H2020/957769/EU/Towards Intelligent DC-based hybrid Grids Optimizing the network performance/TIGON This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No H2020 957769-TIGON info:eu-repo/semantics/openAccess by https://creativecommons.org/licenses/by/4.0/deed.es info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion García-Martínez, Eduardo Abad, J. Ignacio Pinilla-Torremocha, Jorge Sanz-Osorio, José F. Universidad de Zaragoza (orcid)0000-0001-7407-0608 Melero, Julio J. Universidad de Zaragoza (orcid)0000-0003-2360-0845 5009 535 Universidad de Zaragoza Dpto. Ingeniería Eléctrica Área Ingeniería Eléctrica 13 (2025), 148047-148059 IEEE Access IEEE Access 2169-3536 9262651 http://zaguan.unizar.es/record/162560/files/texto_completo.pdf Versión publicada 2208957 http://zaguan.unizar.es/record/162560/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:162560 articulos driver 2025-10-17-14:16:09 ARTICLE