Title
Cryogenic H-Bridge Converter for HTS Degaussing Application
Author
Wikkerink, D.P. (TU Delft High Voltage Technology Group)
Gagic, Mladen (TU Delft ESP LAB; TU Delft DC systems, Energy conversion & Storage) 
Mor, A. R. (Universitat Politécnica de Valencia)
Polinder, H. (TU Delft Transport Engineering and Logistics)
Ross, Robert (TU Delft Ship Hydromechanics and Structures; Institute for Science and Development)
Date
2024
Abstract
A degaussing system can be used to reduce the detectability of the magnetic signature of a ship. Commonly, a degaussing system consists of a set of onboard copper coils that produce a magnetic field to compensate for the magnetic signature. High-temperature superconductive degaussing coils are considered an alternative to copper degaussing coils because of a reduction in energy losses, weight, volume, and costs. The losses of a high-temperature superconductor (HTS) degaussing system can be reduced even further by powering it with a cryocooled converter with parallel mosfets. A low-duty cycle and smaller current leads can be used. These solutions eliminate most of the power source losses. This article investigates such a cryocooled converter. The effect of the low switching frequency on the converter performance is tested. A prototype that can operate at cryogenic temperatures was built. The converter powers an HTS coil. It was found that a load current of 50 A can be achieved with a duty cycle of just 0.025 at an input voltage of 3.5 V while still meeting the requirement of a maximum current ripple of 0.5%. At a switching frequency higher than 100 Hz, the converter's performance deteriorates. Also, oscillations were observed in the circuit. This is a problem due to the low blocking voltage of the mosfets. The parasitic inductances in the circuit have a high impact on the performance because the resistance in the circuit is very low.
Subject
Converter
cryocooled electronics
cryostat
degaussing
high temperature superconductors
magnetic signature
parallel MOSFETs
ReBCO
To reference this document use:
http://resolver.tudelft.nl/uuid:cecaa425-5484-40fa-8c27-a130fa014fe2
DOI
https://doi.org/10.1109/tasc.2023.3337767
Embargo date
2024-05-30
ISSN
1051-8223
Source
IEEE Transactions on Applied Superconductivity, 34 (1)
Bibliographical note
Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.
Part of collection
Institutional Repository
Document type
journal article
Rights
© 2024 D.P. Wikkerink, Mladen Gagic, A. R. Mor, H. Polinder, Robert Ross