Electrical, magnetic and thermal circuit modelling of a superconducting half-wave transformer rectifier flux pump using Simulink

Abstract

Superconducting flux pumps (FP) are capable of supplying superconducting circuits with high currents by additively supplying current over a number of cycles without introducing large amounts of heat into the cryogenic environment. Superconducting FPs can be broadly classified into two types: dynamo and transformer rectifier. Modelling the behaviour of these systems is an emerging field. In this work a model of a half wave magnetically switched transformer rectifier FP created in MATLAB/Simulink/Simscape is presented. Unlike existing models, the characteristics of all circuit elements are fully integrated allowing all superconducting elements to be accurately incorporated. The presented method uses pre-calculated look-up tables, populated with experimentally derived material qualities to simulate these superconducting elements. The thermal evolution of the switches, calculated simultaneously to the magnetic field switching interaction has also been included. This model is compared to the performance of a real world FP during the pumping of a load coil and is found to be accurate. Furthermore, the presented model illustrates how small amounts of heating at a magnetic switch can profoundly affect a FPs performance over many cycles.