A Hybrid Multilevel Converter-Based High-Gain Isolated DC/DC Converter for Grid-Tied Energy Storage Applications
A 7 kV/400 V isolated DC-DC converter utilizing 6.5 kV and 3.3 kV SiC MOSFETs is proposed for medium-voltage energy storage systems. The topology integrates a switched capacitor (SC) stage with modular multilevel converter (MMC) structure, achieving 12:1 voltage step-down before transformer isolation. The SC stage operates at 1 kHz with 6.5 kV devices, while MMC submodules switch at 20 kHz using 3.3 kV devices, enabling 40 kHz transformer operation through frequency multiplication. Capacitor voltage self-balancing is achieved through a novel switching scheme, and power flow is regulated through phase-shift control between primary and secondary voltages of transformer. Zero-voltage switching is realized for MMC sub-modules during voltage transitions. Simulation results validate the design, and experimental characterization of SiC devices demonstrates switching performance with dv/dt up to 40 V/ns.
Authors
- Pengyu Fu (ORCID: https://orcid.org/0000-0002-4251-8209)
- Anant Agarwal (ORCID: https://orcid.org/0000-0003-0228-8039)
- Yizhou Cong (ORCID: https://orcid.org/0000-0002-2656-4547)
- Jin Wang (ORCID: https://orcid.org/0000-0002-4559-5242)
- Zhining Zhang (ORCID: https://orcid.org/0000-0002-1202-2333)
Institutions
- The Ohio State University (US)
Publication Details
- Published
- 2025-03-16
- DOI
- https://doi.org/10.1109/apec48143.2025.10977476
- Primary Topic
- HVDC Systems and Fault Protection
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- U.S. Department of Energy