Picture of athlete cycling

Open Access research with a real impact on health...

The Strathprints institutional repository is a digital archive of University of Strathclyde's Open Access research outputs. Strathprints provides access to thousands of Open Access research papers by Strathclyde researchers, including by researchers from the Physical Activity for Health Group based within the School of Psychological Sciences & Health. Research here seeks to better understand how and why physical activity improves health, gain a better understanding of the amount, intensity, and type of physical activity needed for health benefits, and evaluate the effect of interventions to promote physical activity.

Explore open research content by Physical Activity for Health...

Analysis and design of a modular multilevel converter with trapezoidal modulation for medium and high voltage dc-dc transformers

Gowaid, I. A. and Adam, Grain P. and Ahmed, Shehab and Holliday, Derrick and Williams, Barry W. (2015) Analysis and design of a modular multilevel converter with trapezoidal modulation for medium and high voltage dc-dc transformers. IEEE Transactions on Power Electronics, 30 (10). pp. 5439-5457. ISSN 0885-8993

[img]
Preview
Text (Gowaid-etal-IEEETPE-2015-Analysis-and-design-of-a-modular-lutlilevel-converter-with-trapezoidal-modulation)
06977967.pdf - Final Published Version
License: Creative Commons Attribution 4.0 logo

Download (2MB) | Preview

Abstract

Conventional dual active bridge topologies provide galvanic isolation and soft-switching over a reasonable operating range without dedicated resonant circuits. However, scaling the two-level dual active bridge to higher dc voltage levels is impeded by several challenges among which the high dv/dt stress on the coupling transformer insulation. Gating and thermal characteristics of series switch arrays add to the limitations. To avoid the use of standard bulky modular multilevel bridges, this paper analyzes an alternative modulation technique where staircase approximated trapezoidal voltage waveforms are produced; thus alleviating developed dv/dt stresses. Modular design is realized by the utilization of half-bridge chopper cells. Therefore, the analyzed converter is a modular multi-level converter operated in a new mode with no common-mode dc arm currents as well as reduced capacitor size, hence reduced cell footprint. Suitable switching patterns are developed and various design and operation aspects are studied. Soft switching characteristics will be shown to be comparable to those of the two-level dual active bridge. Experimental results from a scaled test rig validate the presented concept.