Design of an Experimental Test Bench for High-Temperature Superconducting tapes: Magnetic Field Dependence  of Its Critical Density Current

Francisco Alberto Cavaco de Sousa Pereira de Carvalho

Key information

Authors:

Francisco Alberto Cavaco de Sousa Pereira de Carvalho (Francisco Alberto Cavaco de Sousa Pereira de Carvalho)

Supervisors:

Francisco Ferreira da Silva; Paulo José da Costa Branco (Paulo José da Costa Branco)

Published in

November 28, 2022

Abstract

Research has been conducted on the subject of superconducting electrical motors. One research topic is the substitution of conventional windings to HTS tapes windings. For this purpose, test benches with specific characteristics that provide controllable experimental conditions need to be developed. In this work, a test bench is designed and developed to characterize the HTS tape transport current dependency with an external magnetic field. This test bench is used to apply a uniform magnetic field pulse to the HTS tape. To this end, it was designed and developed a Helmholtz coil with a pulsed current supply circuit. The Helmholtz coil behaviour was analyzed analytically and with FEM simulations for validation. The pulse circuit was assembled based on capacitor discharge techniques in the interest of generating the required magnetic field. Instrumentation for measuring the tape’s current and voltage was studied, designed and developed, namely a Rogowski coil, voltage taps, respectively. Additionally, a fluxmeter was designed to measure the Helmholtz coil applied field. Experimental tests were performed to assess the performance of the constructed test bench and to demonstrate the test bench capabilities. From these tests, it was concluded that the test bench has a good level of performance, and it is possible to perform experiments to study the dependence of the transport current with the external applied magnetic field. Some limitations were encountered: large movement of the tape due to Lorentz forces, and insufficient sensitivity in the measurement of the HTS tape voltage.