Fast Current Regulation and Persistent Current Maintenance of High-Temperature Superconducting Magnets with Contact Power Supply and Flux Pump

TL;DR

This paper introduces a method combining contact DC power supply and flux pump with a persistent current switch to rapidly regulate and maintain high-temperature superconducting magnet currents, enhancing their industrial applicability.

Contribution

It presents a novel power strategy that enables fast current regulation and stable persistent current maintenance in large inductance HTS magnets using flux pumps.

Findings

Achieved rapid current regulation in large inductance HTS magnets.

Demonstrated stable persistent current operation with flux pump control.

Enabled potential industrial applications of flux pumps for HTS magnets.

Abstract

Due to the properties of high temperature superconducting (HTS) materials, current attenuation is inevitable during the closed-loop operation of HTS magnets. When a contact DC power supply is used to supplement this attenuation, it inevitably creates a huge thermal burden on the cryogenic system. The flux pump is a revolutionary new power source that can charge closed-loop HTS magnet wirelessly. However, for HTS magnets with a large inductance, such as particle accelerator magnets and magnetic confinement magnet in Tokamak devices, the flux pump cannot fast adjust the DC current of the magnet, due to its small DC output voltage. Here, we present a method to fast regulate the current in a closed-loop HTS magnet using a contact DC power supply and persistent current switch (PCS). After current regulation, the HTS magnet is operated in the persistent current mode (PCM) with a flux pump. By applying the "four-quadrant" control theory of the flux pump allows, the current in HTS magnet is controlled with high stability. This study provide a power strategy for the fast current regulation and maintenance of persistent current in the HTS magnet, enabling the industrial applications of flux pumps for HTS magnets with large inductance.