A HTS Flux Pump Simulation Methodology Based on the Electrical Circuit

Self Cite

This paper presents experimental and modelling results of an ultra-compact self-rectifier flux pump energizing a superconducting coil. The device fits inside a volume of 65x65x50 mm and generates up to 320 A dc through the coil and a peak output voltage up to 60 mV. We also develop and present a full electromagnetic effective circuit model of the flux pump and compare its predictions to the experimental results. We show that our model can reproduce accurately the charging of the load coil and that it reproduces the systematic dependence of the maximum load coil current on the input current waveform. The experiments and modelling together show also the importance of dc-flux offsets in the transformer core on the final achievable current through the coil. The miniaturization possible for this class of flux pump and their minimal heat-leak into the cryogenic environment from thermal conduction make them attractive for applications with demanding size, weight and power limitations. Our effective circuit model is a useful tool in the understanding, design and optimization of such flux pumps which will accelerate their progression from research devices to their application.

Section: Discussionsupporting

confidence: 71%

Section: Introductionmentioning

confidence: 99%

Effective circuit modelling and experimental realization of an ultra-compact self-rectifier flux pump

Mallett

Venuturumilli

Geng

et al. 2023

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“…This is because the magnetic flux produced by induced current in the HTS ring cancels out the external magnetic flux. The simulation results obey the fluxconservation theorem proposed by Landau and Lifshitz [33], the magnetic flux in the ring-shaped finite-gap superconductor remains constant under the variation of external magnetic field, expressed by (7). where LI is the magnetic flux produced by the induced current in the superconductor ring, Φ e is the externally applied magnetic flux, Φ s is the initial magnetic flux through the superconductor ring, L is the inductance of ring, and I is the current induced in the superconductor ring.…”

Section: Verificationsupporting

confidence: 70%

“…In lots of applications, the HTS devices which require current leads, slip rings or brushes have to face the challenges such as large heat load and complex structure [4]. In order to solve the problem, some methods have been proposed such as flux pumps [5][6][7]. However, flux pumps could achieve wireless * Author to whom any correspondence should be addressed.…”

Section: Introductionmentioning

confidence: 99%

Dynamic modelling methodology for an HTS energy converter using moving mesh

Xin

et al. 2021

Self Cite

Lots of high-temperature superconducting (HTS) devices which require current leads, slip rings or brushes have to face the challenges such as large heat load and complex structure. Recently, an HTS energy converter has been proposed, which can not only induce but also exploit persistent current in a closed HTS ring, realizing the conversion of mechanical energy—electromagnetic energy—mechanical energy wirelessly. In this work, a dynamic modelling method based on the H-formulation and moving mesh has been proposed to accurately simulate the electromagnetic performance of the HTS energy converter. The proposed modelling method can depict the induced current density inside the superconductor and magnetic field distribution, serving as a powerful tool to analyze the complex working principle of the HTS energy converter. The validity of the model has been verified by experimental results. Besides, effects of different parameters of the energy converter have been investigated in detail by our proposed model, to provide further insight into the design and applications of the device.

“…The critical temperature and magnetic field of hightemperature superconducting (HTS) materials are significantly higher than those of low-temperature superconducting materials [1]. Coils made of HTS materials have significant potential for high-field applications because of their extremely high current-carrying capacity under high magnetic fields [2,3]. However, HTS coils cannot operate in persistent current * Author to whom any correspondence should be addressed.…”

Section: Introductionmentioning

confidence: 99%

Miniaturized HTS linear flux pump with a charging capability of 120 A

Chen

et al. 2023

Owing to the presence of joint resistance and flux creep, high-temperature superconducting (HTS) coils without a power supply inevitably suffer from current decay. A flux pump is a voltage supply that requires connections with smaller footprints and a lower heat load than traditional current leads. In this study, we explain the principle of the upper limit for the output current of the traveling wave flux pumps. Based on this principle, a miniaturized linear flux pump device was developed. With narrow and misaligned iron teeth, elaborate 3D geometry of the iron pieces, and optimized driving current waveform, the miniaturized flux pump can support more than 120 A output current with only a 10 mm wide HTS tape and a compact size of 4.6 × 4.6 × 3.4 cm. Our experimental results show that the critical current of the HTS tape has a significant effect on the flux pump output. An HTS tape with a larger critical current supports a higher maximum transport current, whereas an HTS tape with a smaller critical current requires less applied current for positive output. Finally, excitation tests on HTS coils were performed. Charge/active discharge and field supplement experiments were done on a maglev HTS racetrack coil of 0.4 H, where charging/field supplement capbility of the miniaturized flux pump were demonstrated up to 46.8 A (close to the critical current of the coil). It has also been proved that the flux pump can work together with an external power supply with persistent current switch. The miniaturized flux pump can also independently charge an HTS coil of 60 μH to 91.6 A, which is the critical current of the coil at a low voltage criterion.