Design for a Persistent Current Switch Controlled by Alternating Current Magnetic Field

IEEE Trans. Appl. Supercond.

Bumby

et al. 2022

Self Cite

High-temperature superconducting (HTS) magnets offer a novel pathway to magnetically confined fusion energy generation. Reactor-scale fusion devices require tens of kA of current to generate large toroidal fields for magnetic confinement.Operating HTS magnets at kA-current levels is difficult due to unavoidable joint resistances that require active driving of current. The large footprint and energy demand of a solidstate power supply and multi-kA current leads present significant constraints on the size, cost and efficiency of a fusion tokamak. An alternative approach is to use an HTS flux pump, which can generate and sustain persistent currents in HTS coils at the kAlevels required by fusion magnet systems. Here, we outline the design of a 60 kA transformer-rectifier flux pump for energizing and sustaining an 80 mH HTS fusion magnet. The flux pump is driven by an iron-core transformer with copper primary and HTS secondary windings. This is rectified by switching elements in the superconducting circuit into a uni-directional dc voltage output which charges the inductive load. To charge the load coil to 60 kA in 24 hours, an output dc voltage of 55 mV is needed. However, only 6 mV is required to maintain a long-term steady current of 60 kA. Such a device can significantly reduce the cost and footprint of future fusion reactor designs.

Section: Design Parameters Of a 60 Ka Flux Pumpmentioning

confidence: 99%

Design of a 60 kA Flux Pump for Fusion Toroidal Field Coils

Rice

IEEE Trans. Appl. Supercond.

Bumby

et al. 2022

Self Cite

“…The superconducting tape, wound around the inner iron core, is connected to the superconducting magnet it energizes. To avoid the induced voltage from the copper coil, the superconducting tape should be wound in the bifilar manner [8]. Two superconducting tapes are soldered together at one end by the same soldering technique used in [1,9,10].…”

Section: A Structure Design Of Pcsmentioning

confidence: 99%

Persistent Current Switch for HTS Superconducting Magnets: Design, Control Strategy, and Test Results

IEEE Trans. Appl. Supercond.

Shen

et al. 2019

Self Cite

High temperature superconductor (HTS) is becoming more and more attractive for the application in high field magnets which can be utilized in the magnetic resonance imaging (MRI) and rotating machines. To charge the HTS magnets and operate them in persistent current mode, a persistent current switch (PCS) is very necessary. This paper will focus on how to build a fast persistent current switch controlled by AC magnetic field. The PCS can present a large resistance rapidly compared with conventional PCS and recover to zero-resistance in a short recovery time. Impacting factors and strategy to control the proposed PCS are discussed. An experimental system is built and tests are carried out to verify the practicality of the proposed PCS.

“…The bridge design is different from our previous work. We used a bifilar structure [26] in the bridge, as shown in Fig. 3(a)and Fig.…”

Section: The Transformer-rectifier Flux Pumpmentioning

confidence: 99%

Flux pumping for non-insulated and metal-insulated HTS coils

Supercond. Sci. Technol.

Coombs

2017

Self Cite

：High-Temperature Superconducting (HTS) coils wound from coated conductors without turn-to-turn insulation (NI coils) have been proven with excellent electrical and thermal performances. However, the slow charging of NI coils has been a long lasting problem. In this work, we explore using a transformer-rectifier HTS flux pump to charge an NI coil and a Metal-Insulated (MI) coil. The charging performance comparison is made between different coils. Comprehensive study is done to thoroughly understand the electrical-magnetic transience in charging these coils. We will show that the low-voltage high-current flux pump is especially suitable for charging NI coils with very low characteristic resistance.