TY - JOUR
T1 - Modelling the Frequency Dependence of the Open-Circuit Voltage of a High-Tc Superconducting Dynamo
AU - Ainslie, Mark D.
AU - Quéval, Loïc
AU - Mataira, Ratu C.
AU - Bumby, Chris W.
N1 - Funding Information:
Manuscript received December 14, 2020; revised December 22, 2020 and January 19, 2021; accepted February 3, 2021. Date of publication February 8, 2021; date of current version March 26, 2021. The work of Mark D. Ainslie was supported by the Engineering and Physical Sciences Research Council (EPSRC) Early Career Fellowship under Grant EP/P020313/1. This work was supported by the Royal Society of New Zealand Marsden Fund under Grant MFP-VUW1806 and EolSupra20 Project ANR-10-LABX-0040-LaSIPS. (Corresponding author: Mark D. Ainslie.) Mark D. Ainslie is with the Bulk Superconductivity Group, Department of Engineering, University of Cambridge, Cambridge CB2 1PZ, U.K. (e-mail: [email protected]).
Publisher Copyright:
© 2002-2011 IEEE.
PY - 2021/2/8
Y1 - 2021/2/8
N2 - A high-Tc superconducting (HTS) dynamo enables the injection of large DC currents into a superconducting circuit, without the requirement for current leads. In this work, we attempt to explain the frequency dependence of such dynamos/flux pumps reported in the literature, where it is observed that the rate at which the open-circuit DC voltage increases reduces with increasing frequency, in contrast to the expected linear behaviour. Heat generated in the HTS wire has been the common explanation given to date for this phenomenon. Here we offer an alternative explanation: the interaction between and current flow in the different layers of the HTS wire as the frequency of the dynamo increases. Our claim is based on numerical analysis using a segregated H-formulation finite-element model of the HTS dynamo benchmark problem that is extended to include the full HTS wire architecture and coupled with a thermal model. This framework enables us to efficiently model the relative movement between the rotating roomerature permanent magnet and the stationary HTS wire and to study the impact of the frequency of rotation and temperature on the open-circuit DC voltage of the dynamo.
AB - A high-Tc superconducting (HTS) dynamo enables the injection of large DC currents into a superconducting circuit, without the requirement for current leads. In this work, we attempt to explain the frequency dependence of such dynamos/flux pumps reported in the literature, where it is observed that the rate at which the open-circuit DC voltage increases reduces with increasing frequency, in contrast to the expected linear behaviour. Heat generated in the HTS wire has been the common explanation given to date for this phenomenon. Here we offer an alternative explanation: the interaction between and current flow in the different layers of the HTS wire as the frequency of the dynamo increases. Our claim is based on numerical analysis using a segregated H-formulation finite-element model of the HTS dynamo benchmark problem that is extended to include the full HTS wire architecture and coupled with a thermal model. This framework enables us to efficiently model the relative movement between the rotating roomerature permanent magnet and the stationary HTS wire and to study the impact of the frequency of rotation and temperature on the open-circuit DC voltage of the dynamo.
KW - finite-element modelling
KW - flux pump
KW - H-formulation
KW - HTS dynamo
KW - HTS modelling
UR - http://www.scopus.com/inward/record.url?scp=85101455262&partnerID=8YFLogxK
U2 - 10.1109/TASC.2021.3057842
DO - 10.1109/TASC.2021.3057842
M3 - Article
AN - SCOPUS:85101455262
SN - 1051-8223
VL - 31
JO - IEEE Transactions on Applied Superconductivity
JF - IEEE Transactions on Applied Superconductivity
IS - 5
M1 - 9350153
ER -