Modular Multilevel Series-Parallel Converter with Parallel-Connected Phases and Coupled Inductors for High-Current Applications

Conference paper (2023)

Authors

Esteban Concha Centro de Energia UCSC
Sebastian Rivera DC systems, Energy conversion & Storage - EEMCS
Apparao Dekka Lakehead University
Ricardo Lizana Centro de Energia UCSC
Research Group
DC systems, Energy conversion & Storage (EEMCS) (TU Delft)
Copyright: © 2023 Esteban Concha, Sebastian Rivera, Apparao Dekka, Ricardo Lizana F.
DOI
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https://doi.org/10.1109/CHILECON60335.2023.10418732
MMSPC Cross-circulating current Coupled inductors
More Info
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Published Date

2023

Language

English

Reuse Rights

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Faculty

Electrical Engineering, Mathematics and Computer Science

Department

Electrical Sustainable Energy

Research Group

DC systems, Energy conversion & Storage

Abstract

Modular multilevel series-parallel converters (MM-SPC) have become a suitable solution to provide higher operating voltages, fault tolerance operation, and reliability at a reduced cost, due to their ability to achieve a simpler internal voltage balance. Therefore, MMSPC is a promising solution for applications where the nominal operating conditions are high voltage levels on the DC side and high current ratings on the AC side of the system. To allow this operation, it is necessary to design the system with parallelization in each phase. Therefore, this article proposes a design that incorporates parallelization in each phases and analyzes the internal cross-circulating current generated due to parallelization. This current creates an unbalance and internal losses in the converter. In order to compensate for the cross-circulating current, two cases are compared: the first one with decoupled inductors in their phases, and the second one with coupled inductors. This way, a comparison is made to determine which case provides greater compensation of the circulating current, allowing for the delivery of a high current at the converter's output with the least possible imbalance and internal losses.