D30.3 - A High-Performance Flying Capacitor Multilevel Dual Active Bridge DC-DC Converter for Isolated Automotive Systems

Thursday, March 26, 2026

12:00 PM - 1:45 PM CT

Location: Poster 8

Technical Dialogue Presenter(s)

SK

Sahana Krishnan (she/her/hers)

University of California Berkeley

Co-Author(s)

Francesca Giardine

University of California, Berkeley
Syed Tahmid Mahbub

University of California, Berkeley
Logan Horowitz

CU Boulder
RP

Robert C.N. Pilawa-Podgurski

UC Berkeley

Legacy power architectures in automotive systems are being replaced by higher voltage rails to reduce conduction losses. High-step-down power conversion is therefore necessary to derive auxiliary voltage rails, such as 48 V from the main supply. Isolation is also critical for power converters within these systems to meet safety requirements. This work presents an isolated dc-dc converter for an 800 V automotive application. The converter topology is derived from the dual active bridge converter and the flying capacitor multilevel converter. The primary side of the proposed converter comprises a 6-level flying capacitor multilevel stage. This is connected to the secondary-side full-bridge rectifier via a transformer. The proposed topology is validated in hardware using a planar magnetic implementation of the galvanically isolated transformer. The converter demonstrates greater than 95% efficiency across the full load range at a high conversion ratio making it a compelling alternative to a conventional dual active bridge converter.