MATLAB Implementation of an HTS Transformer-Rectifier Flux Pump Using HTS Dynamic Voltage Switches

Abstract

Thispaper proposes a novel approach to the modelling of HTS transformer-rectifier flux pumps that can charge HTS magnetic loads without the need for bulky current leads or expensive cryogenic requirements. The model was built in MATLAB/Simulink for a flux pump with 2 HTS switches, an HTS transformer with a primary inductance of 15 mH, secondary inductance of 50 µH and an HTS magnetic load with an inductance of 2 mH. With a 5 A pk-pk triangular current waveform at 2 Hz the system can load the HTS load to 34.63 A in 5 s. This incremental addition of flux to the load demonstrates the advantage of flux pumps as they can charge high-field magnets without the need for large power sources. The speed of flux pumping is improved by increasing the system frequency, the magnitude of the dynamic voltage developed in the HTS switches and by increasing the primary inductance of the transformer. This has widespread industrial applicability in fields such as the charging of high-field magnets for MRI systems.