3D modeling of a Superconducting Dynamo-Type Flux Pump

TL;DR

This paper introduces the first 3D model of a high-temperature superconducting flux pump, providing insights into its mechanism, electric field distribution, and measurement accuracy, which advances understanding of superconducting dynamo operation.

Contribution

The paper presents a novel 3D model of an HTS flux pump that aligns well with experiments and reveals detailed characteristics of flux pumping mechanisms.

Findings

Good agreement between model and experiments

Identified the role of overcritical screening current in flux pumping

Analyzed electric field and screening current effects on voltage generation

Abstract

High temperature superconducting (HTS) dynamos are promising devices that can inject large DC currents into the winding of superconducting machines or magnets in a contactless way. Thanks to this, troublesome brushes in HTS machines or bulky currents leads with high thermal losses will be no longer required. The working mechanism of HTS dynamo has been controversial during the recent years and several explanations and models have been proposed to elucidate its performance. In this paper, we present the first three-dimensional (3D) model of an HTS flux pump, which has good agreement with experiments. This model can be beneficial to clarify the mechanism of the dynamo and pinpoint its unnoticed characteristics. Employing this model, we delved into the screening current and electric field distribution across the tape surface in several crucial time steps. This is important, since the overcritical screening current has been shown to be the reason for flux pumping. In addition, we analyzed the impact of both components of electric field and screening current on voltage generation, which was not possible in previous 2D modeling. We also explored the necessary distance of voltage tab at different airgaps for precise measurement of the voltage across the tape in the dynamo.