Self-protection mechanisms in no-insulation (RE)Ba2Cu3Oxhigh temperature superconductor pancake coils

Wang, Y; Chan, Wan Kan; Schwartz, J.

doi:10.1088/0953-2048/29/4/045007

Cited by 211 publications

(140 citation statements)

References 17 publications

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“…For the REBCO tape in this test, k=0.05869, b=0.7636, B c =101.7 mT. 40 Only half-section of the coil is solved in this model due to the symmetry along axial direction. The model is solved by a commercial FEM software Comsol Multiphysics TM .…”

Section: B Numerical Modelmentioning

confidence: 99%

Magnetization of the joint-free high temperature superconductor (RE)Ba2Cu3Ox coil by field cooling

Zheng

Wang

et al. 2017

AIP Advances

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Joint-free (RE)Ba2Cu3Ox (REBCO) coil based on ‘wind-and-flip’ technique has been developed to generate a persistent magnetic field without power supply. This paper is to study the magnetization characteristics of the joint-free REBCO coil by field cooling, in order to trap higher field. A joint-free pancake coil is wound by REBCO tapes and the field cooling magnetization test is performed on it. An approximate numerical model based on H-formulation is built for this coil to analyze its magnetization behavior, which is validated by the experimental results Analysis show that a persistent direct current is induced in the coil during the field cooling operation, which generates the trapped field. The induced current of the joint-free coil shows an intrinsic non-uniform distribution among turns. Increasing the magnetization field and critical current of REBCO conductors can considerably increase the trapped field. But the trapping factor (the rate of trapped field to background magnetization field) reaches a maximum value (60 % for the test coil). This maximum value is an intrinsic characteristics for a fabricated coil, which only depends on the coil’s geometry structure. With a same usage of REBCO tapes, the trapping factor can be improved significantly by optimizing the coil structure to multiple pancakes, and it can approach 100 %.

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Section: B Numerical Modelmentioning

confidence: 99%

Magnetization of the joint-free high temperature superconductor (RE)Ba2Cu3Ox coil by field cooling

Zheng

Wang

et al. 2017

AIP Advances

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“…Therefore, in order to apply superconducting coils wound with HTS wiring to electrical machines, it is very important to protect the HTS coils from the quenching phenomenon. The approach known as the no-insulation (NI) winding technique is a viable quench-protection method for HTS coils [16][17][18][19][20][21][22][23][24][25]. The NI winding technique involves the fabrication of coils without insulation materials between the turns.…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, the current flows through the stabilizer layer constituting the superconducting wire, and it is thus bypassed. As a result, NI coils can be protected from quenching without complicated quench detection schemes and/or protection devices, simplifying these HTS coil systems [16][17][18][19][20][21][22][23][24][25]. However, the NI HTS coil is associated with an intrinsic charging/discharging delay phenomenon.…”

Section: Introductionmentioning

confidence: 99%

A Flux-Controllable NI HTS Flux-Switching Machine for Electric Vehicle Applications

2020

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This paper deals with a flux-controllable NI HTS flux-switching machine (FSM) for electric vehicle (EV) applications. In a variable-speed rotating machine for EVs, such as electric buses, electric aircraft and electric ships, an electric motor capable of regulating the flux offers the advantage of constant output operation. In general, conventional HTS rotating machines have excellent flux-regulation performance, because they excite an HTS field coil. However, it is difficult to ensure any flux-regulation capabilities in HTS rotating machines using HTS field coils that apply the no-insulation (NI) winding technique, due to the inherent charge and discharge delays in these machines. Nevertheless, the NI winding technique is being actively researched as a key technology for the successful development of HTS rotating machines, because it can dramatically improve the operational stability of HTS field coils. Therefore, research to implement an HTS rotating machine with flux-regulation capabilities, while improving the operating stability of the HTS field coil using the NI winding technique, is required for EV applications. In this paper, we propose an HTS rotating machine with a flux switching structure, a type of topology of a rotating machine that is being actively studied for application to the electric motors used in EVs. The proposed HTS flux-switching machine (FSM) uses NI field coils, but additional field windings are applied for flux regulation, which enables flux control. In this study, an NI HTS field coil was also fabricated and tested because the characteristic resistance value should be used for the design and characteristic analyses of machines which utilize an NI coil. The simulation model used to analyze the flux-regulation performance capabilities of the NI HTS FSM were devised based on the characteristic resistance values obtained from a charging test of the fabricated NI HTS field coil. This study can provide a good reference for further research, including work on the manufacturing of a prototype NI HTS FSM for EV applications, and it can be used as a reference for the development of other HTS rotating machines, such as those used in large-scale wind power generation, where flux-regulation capabilities are required.

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“…The SMES is characterised by an outstanding power density and is able to response to the power requirements very quickly [2,[15][16][17][18]. However, the energy density of the SMES is much lower than that of the battery [19]. The concept of the SMES/battery hybrid energy storage is, therefore, proposed by combining two kinds of complementary energy storages.…”

Section: Introductionmentioning

confidence: 99%

Design and real-time test of a hybrid energy storage system in the microgrid with the benefit of improving the battery lifetime

Xiong

et al. 2018

Applied Energy

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• A new control method of the hybrid energy storage system is introduced.• The battery lifetime has been proved to be extended in the real-time experiment.• A new experiment method is proposed using the RTDS&HIL to give real-time verification.• A battery lifetime prediction method is introduced.• The RTDS&HIL scheme highlights a flexible real-time experimental approach. This study proposes a hybrid energy storage system (HESS) composed of the superconducting energy storage system (SMES) and the battery. The system is designed to compensate power fluctuations within a microgrid. A novel control method is developed to share the instantaneous power between the SMES and the battery. The new control scheme takes into account the characteristics of the components of the HESS, and the battery charges and discharges as a function of the SMES current rather than directly to the power disturbances. In this way, the battery is protected from the abrupt power changes and works as an energy buffer to the SMES. An new hardware-in-loop experiment approach is introduced by integrating a real-time digital simulator (RTDS) with a control circuit to verify the proposed hybrid scheme and the new control method. This paper also presents a battery lifetime prediction method to quantify the benefits of the HESS in the microgrid. A much better power sharing between the SMES and the battery can be observed from the experimental results with the new control method. Moreover, compared to the battery only system the battery lifetime is quantifiably increased from 6.38 years to 9.21 years.

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Self-protection mechanisms in no-insulation (RE)Ba₂Cu₃O_xhigh temperature superconductor pancake coils

Cited by 211 publications

References 17 publications

Magnetization of the joint-free high temperature superconductor (RE)Ba2Cu3Ox coil by field cooling

Magnetization of the joint-free high temperature superconductor (RE)Ba2Cu3Ox coil by field cooling

A Flux-Controllable NI HTS Flux-Switching Machine for Electric Vehicle Applications

Design and real-time test of a hybrid energy storage system in the microgrid with the benefit of improving the battery lifetime

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