Analysis on circulating current frequency of chain-link modular multilevel DC-DC converters for low step-ratio high-power MVDC applications
Author(s)
Type
Conference Paper
Abstract
The direct chain-link modular multilevel dc
converter has raised great interest recently in medium/high-
voltage dc-dc conversion due to the high power device utilization
and lower power losses than the front-to-front configurations of
modular multilevel converter. This paper introduces a single-
phase chain-link modular multilevel buck-boost converter for
medium voltage dc applications and presents an analysis
methodology on its internal circulating current frequency. Its
connection and comparison with the classic dc-ac modular
multilevel converter are given first, and its dc and ac components
are analyzed in the respective equivalent circuits. Then, the
derivation methodology for the proper circulating current
frequency with lowest internal reactive power is provided, which
could minimize the current stress and decrease the power losses.
Also, this method can be directly applied in the derivative
topologies and further configurations to satisfy various conversion
requirements. The theoretical analysis is verified by a set of full-
scaled simulations and further verified against experimental tests
on a down-scaled prototype.
converter has raised great interest recently in medium/high-
voltage dc-dc conversion due to the high power device utilization
and lower power losses than the front-to-front configurations of
modular multilevel converter. This paper introduces a single-
phase chain-link modular multilevel buck-boost converter for
medium voltage dc applications and presents an analysis
methodology on its internal circulating current frequency. Its
connection and comparison with the classic dc-ac modular
multilevel converter are given first, and its dc and ac components
are analyzed in the respective equivalent circuits. Then, the
derivation methodology for the proper circulating current
frequency with lowest internal reactive power is provided, which
could minimize the current stress and decrease the power losses.
Also, this method can be directly applied in the derivative
topologies and further configurations to satisfy various conversion
requirements. The theoretical analysis is verified by a set of full-
scaled simulations and further verified against experimental tests
on a down-scaled prototype.
Date Issued
2018-12-06
Date Acceptance
2018-06-28
Citation
2018
Publisher
IEEE
Copyright Statement
© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
Identifier
https://ieeexplore.ieee.org/document/8558030
Source
IEEE ECCE 2018
Subjects
Science & Technology
Technology
Energy & Fuels
Engineering, Electrical & Electronic
Engineering
modular multilevel converter
dc-dc conversion
multi-terminal networks
MVDC
DC/DC CONVERTER
Publication Status
Published
Start Date
2018-09-23
Finish Date
2018-09-27
Coverage Spatial
Portland, Oregon, USA
Date Publish Online
2018-12-06