Analysis of CHB Capacitor Voltage Ripple in Multiport LLC-Based Solid-State Transformers
Year: 2026
Type: conference-paper
Abstract: Three-stage solid-state transformers (SSTs) have emerged as a promising solution for future grids. Among SST architectures, the cascaded H-bridge (CHB)-based configuration is widely adopted due to its inherent modularity. To achieve high efficiency in the isolated dc-dc stage, LLC resonant converters operating as dc transformers (DCX) are commonly employed. However, modular implementations increase component count, system cost, and complexity. Multiport LLC (MLLC) converters have been proposed as an attractive alternative to reduce the number of components in the dc-dc stage. Due to the instantaneous power behavior of the CHB stage, a second-order harmonic voltage ripple appears in the dc-link capacitors, affecting the dc-dc converter currents and increasing current stress and losses. This work analytically models the ripple propagation mechanism in the MLLC converter and discusses the design impacts. The proposed analysis is validated through simulation and experimental results.
Institution: Eindhoven University of Technology
Language: English
Topic: Advanced DC-DC Converters
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
OpenAlex ID: W7224863576