Simulation of AC Loss in Small HTS Coils With Iron Core

Lai, Lingfeng; Gu, Chen; Qu, Timing; Zhang, Min; Li, Yanqing; Li, Rui; Coombs, Tim; Han, Z.

doi:10.1109/tasc.2014.2375375

Cited by 24 publications

(9 citation statements)

References 18 publications

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“…Experimental work has shown that the transport loss of the stacked tapes positioned in the iron core was greater than that without the iron core [12]. A similar result was obtained for the case of HTS coils with an iron core: an iron core can double the AC loss and this can be explained by magnetic mirror images and a fringe magnetic field [13]. However, the flux diverter can also influence AC losses of HTS tapes and coils in a positive way.…”

Section: Introductionsupporting

confidence: 57%

Numerical study on AC loss reduction of stacked HTS tapes by optimal design of flux diverter

Liu

Zhang

Jing

et al. 2017

Supercond. Sci. Technol.

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High temperature superconducting (HTS) coils are key parts of many AC applications, such as generators, superconducting magnetic energy storage and transformers. AC loss reduction in HTS coils is essential for the commercialization of these HTS devices. Magnetic material is generally used as the flux diverter in an effort to reduce the AC loss in HTS coils. To achieve the greatest reduction in the AC loss of the coils, the flux diverter should be made of a material with low loss and high saturated magnetic density, and the optimization of the geometric size and location of the flux diverter is required. In this paper, we chose Ni-alloy as the flux diverter, which can be processed into a specific shape and size. The influence of the shape and location of the flux diverter on the AC loss characteristics of stacked (RE)BCO tapes is investigated by use of a finite element method. Taking both the AC loss of the (RE)BCO coils and the ferromagnetic loss of the flux diverter into account, the optimal geometry of the flux diverter is obtained. It is found that when the applied current is at half the value of the critical current, the total loss of the HTS stack with the optimal flux diverter is only 18% of the original loss of the HTS stack without the flux diverter. Besides, the effect of the flux diverter on the critical current of the (RE) BCO stack is investigated.

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Section: Introductionsupporting

confidence: 57%

Numerical study on AC loss reduction of stacked HTS tapes by optimal design of flux diverter

Liu

Zhang

Jing

et al. 2017

Supercond. Sci. Technol.

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“…The real AC loss of an assembled coil should exceed the estimated value. Both the iron coupling [34] and the leakage alternating flux generated by the rotor increase AC losses.…”

Section: Temperature Increment Caused By Ac Lossmentioning

confidence: 99%

Thermal analysis for the HTS stator consisting of HTS armature windings and an iron core for a 2.5 kW HTS generator

Song

Lai

et al. 2016

Supercond. Sci. Technol.

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Most present demonstrations of high-temperature superconducting (HTS) synchronous motors/generators are partially superconducting, only installing HTS coils on the rotor as excitation windings. The possible applicability of HTS armature windings is an interesting research topic because these windings can certainly increase the power density attributed to a potentially high armature loading capacity. In this study, we analysed the thermal behaviours of a developed 2.5 kW–300 rpm synchronous generator prototype that consists of an HTS stator with Bi-2223–Ag armature windings on an iron core and a permanent magnet (PM) rotor. The entire HTS stator, including the iron core, is cooled with liquid nitrogen through conduction cooling. The rated frequency is set at 10 Hz to reduce AC loss. The properties of the HTS windings and the iron core are characterized, and the temperatures in the HTS stator under different operation conditions are measured. The estimated iron loss is 11.5 W under operation in 10 Hz at liquid nitrogen temperature. Conduction cooling through the silicon iron core is sufficient to cool the iron core and to compensate for the temperature increment caused by iron loss. The stable running capacity is limited to 1.6 kW when the armature current is 12.6 A (effective values) due to the increasing temperature in the slots as a result of the AC loss in the HTS coils. The thermal contact between the HTS coils and the cooling media should be improved in the future to take away the heat generated by AC loss.

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“…The proposed superferric magnets are based on HTS coil windings coupled with iron cores [2]- [4]. Due to the presence of iron cores, a significant AC loss increase in HTS coil windings was observed, and hence AC loss becomes one of the main concerns of superferric magnets and new generation RCS application [5]- [9].…”

Section: Introductionmentioning

confidence: 99%

AC Loss Reduction in HTS Coil Windings Coupled With an Iron Core

Fang

Amemiya

et al. 2023

IEEE Trans. Appl. Supercond.

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Rapid-cycling synchrotron (RCS) magnets based on a superferric design consist of high temperature superconducting (HTS) coil windings coupled with iron cores. However, the presence of iron cores significantly increases AC loss in HTS coil windings, making AC loss reduction a critical issue for applying HTS technology in RCSs. Enlarging the distance between iron cores and coil windings may reduce AC loss. In addition, magnetic materials with different saturation magnetic fields also may influence AC loss in HTS coil windings coupled with iron cores. To investigate the distance dependence, AC losses of 1DPC (double pancake coil)-, 2DPC-, 4DPC-, and 8DPC assemblies with various distances are simulated using the 3D T-A homogenization method with/without an iron core. Two magnetic materials with different saturation magnetic fields are chosen as the iron core to evaluate AC loss in HTS coil assemblies. The results show that the AC loss values in HTS coil assemblies coupled with the iron core decrease significantly with growing distance. For a given distance and current, when the iron core has a lower saturation field, the AC loss values of the 4DPC assembly are smaller than those with a higher saturation field.

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Simulation of AC Loss in Small HTS Coils With Iron Core

Cited by 24 publications

References 18 publications

Numerical study on AC loss reduction of stacked HTS tapes by optimal design of flux diverter

Numerical study on AC loss reduction of stacked HTS tapes by optimal design of flux diverter

Thermal analysis for the HTS stator consisting of HTS armature windings and an iron core for a 2.5 kW HTS generator

AC Loss Reduction in HTS Coil Windings Coupled With an Iron Core

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