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Chenjie Shi

Bio: Chenjie Shi is an academic researcher from North China Electric Power University. The author has contributed to research in topics: Electrical conductor & Thermoelectric effect. The author has an hindex of 6, co-authored 8 publications receiving 81 citations.

Papers
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Journal ArticleDOI
TL;DR: In this paper, a quasi-isotropic strand made from coated conductors is simulated by the finite element method and tested in liquid nitrogen, which indicates that this strand has high current-carrying capacity.
Abstract: The high-temperature superconducting (HTS) strand, with high current capacity and a round or square cross section, is expected to have widely potential applications in current leads and superconducting power devices since it is easily insulated to avoid point charging. This paper describes a quasi-isotropic strand made from coated conductors. The magnetic field distribution and critical current characteristic of the strand in self-field are simulated by the finite-element method and tested in liquid nitrogen. The result indicates that this strand has high current-carrying capacity. The critical currents in different external magnetic fields and various orientations were measured. It is verified by the experiments that the strand has isotropic characteristics in low magnetic field and weak anisotropy in higher field. The potential of the strands with high engineering current density makes them also suitable for high-field magnets and high-voltage power applications, while maintaining flexibility.

40 citations

Journal ArticleDOI
TL;DR: In this article, the twisting properties and tensile properties of a quasi-isotropic (QI) strand made from 2G tapes were investigated for high-temperature superconducting (HTS) tapes.
Abstract: With the development of second generation (2G) high-temperature superconducting (HTS) tapes, several cabling configurations, such as twisting stacked-tapes cable and conductor on round core cables, have been proposed, and some prototypes were developed. Alternating current (ac) losses arise in HTS tapes in ac operations, and those losses are an important consideration for applications since they influence the stability and operating cost. Conventionally, a twisting technique is used to effectively reduce the ac losses. This paper presents the twisting properties and tensile properties of a quasi-isotropic (QI) strand made from 2G tapes. The strand consists of 2G tapes, aluminum foil, and a metal sheath. A twisting apparatus was designed and demonstrated to research the characteristics of the strands in twisting situations. The critical currents and strain of a single CC were tested for different twist pitches in self-field and at 77 K. The results show that the critical twist pitch of the QI strand is higher than that of a single tape. The critical current of the QI strand was also measured at 77 K after the application of different tensile stresses at room temperature.

11 citations

Journal ArticleDOI
TL;DR: In this paper, the authors presented the thermal stability of a quasi-isotropic strand composed of stacked 2G wires, which was fabricated by mature welding metal sheath, which is outside of the symmetrically arranged wires.
Abstract: This paper mainly presents the thermal stability of a quasi-isotropic strand composed of stacked 2G wires. The strand is fabricated by mature welding metal sheath, which is outside of the symmetrically arranged 2G wires. The sheaths may be made from different kinds of metals, such as copper and aluminum. The stability characteristics of the strands, including the calculation of the minimum quench energy (MQE) and the quench propagation velocity (QPV), are simulated by Comsol 5.0 software and tested by fabricating sample strands. The simulated results are in agreement with the experimental ones.

11 citations

Journal ArticleDOI
TL;DR: In this article, the quench behavior of isotropic strands made from second-generation (2G) coated conductors (CCs) subjected to overcurrent at power frequency and liquid nitrogen, in order to evaluate their prospects for power applications.
Abstract: This paper presents the quench behavior of isotropic strands made from second-generation (2G) coated conductors (CCs) subjected to overcurrent at power frequency and liquid nitrogen, in order to evaluate their prospects for power applications. The isotropic strands with high current capacity, consisting of CCs in parallel, were prepared by putting them into different metal sheaths using industrial soldering techniques and drawing as well as extrusion processes. Current over the critical current was supplied to the sample strands, with a duration of 700 ms, at 77 K. Profiles of the voltage, current, and temperature in the sample strand were recorded during the pulsing overcurrent test. Based on the U(t) and I(t) curves, the resistance of sample strands and phase angle between voltage and current were also obtained. After each pulsing current, the critical current and n-values of the sample strands were retested. The results show that quench characteristics of the sample strands with different sheaths are very different from each other. Additionally, the sample strand fabricated by stainless-steel sheath has stronger current-limited ability than the copper or aluminum sheaths.

10 citations

Journal ArticleDOI
TL;DR: In this paper, a design of quasi-isotropic high-temperature superconducting (HTS) strand made from REBCO coated conductors (REBCO CCs) with geometrical symmetric configuration was put forward and a sample of the strand was fabricated.
Abstract: High-current high-temperature superconducting (HTS) cables made from HTS CCs have widely potential applications in high magnetic field and superconducting power devices. In this paper, a design of quasi-isotropic HTS strand made from REBCO coated conductors (REBCO CCs) with geometrical symmetric configuration was put forward and a sample of the strand was fabricated. It mainly consists of 72 REBCO CCs, metal filler, and sheath. In order to study the anisotropy of critical current, the magnetic field distribution on the cross-section of the strand was simulated and the critical current of the strand in the self-field and in an external magnetic field were calculated by finite element method. The experimental results show the validity of the simulation model and the calculation method.

9 citations


Cited by
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Journal ArticleDOI
TL;DR: In this article, an optimization of round TSTC strand was introduced for simple fabrication in long lengths for versatile use either for the production of cables to be used at high fields or for power transmission.
Abstract: Second-generation high-temperature superconductors (HTS) REBCO are promising for high-field application due to the excellent $j_{c}(B)$ performance at low temperatures and for power transmission at liquid nitrogen temperature. For power transmission with HTS, the formation of high-current HTS cables from single HTS tapes is desirable for cable currents of several 10 kA up to more than 100 kA. On the other hand, to avoid high inductances, which would cause high-voltage problems in case of quench or fast shutdown, high-current HTS cables are needed for larger high-field magnets, too, typically operated at 4.5 K or lower. In the last years, several HTS cable designs have been proposed, such as twisted stacked cable, CORC cable, and Roebel cable. This talk will give an overview of such proposals and highlight actual developments in HTS cable design and REBCO tape optimization, e.g., for highest field. In addition, an optimization of round TSTC strand will be introduced, which is designed for simple fabrication in long lengths for versatile use either for the production of cables to be used at high fields or for power transmission.

72 citations

Journal ArticleDOI
TL;DR: In this article , the authors provide a review of the fault analysis of high-temperature superconductors (HTSs) and discuss the current challenges of HTS cables, and after that current developments of fault behaviour of superconducting cables are presented.
Abstract: Along with advancements in superconducting technology, especially in high-temperature superconductors (HTSs), the use of these materials in power system applications is gaining outstanding attention. Due to the lower weight, capability of carrying higher currents, and the lower loss characteristic of HTS cables, compared to conventional counterparts, they are among the most focused large-scale applications of superconductors in power systems and transportation units. In near future, these cables will be installed as key elements not only in power systems but also in cryo-electrified transportation units, that take advantage of both cryogenics and superconducting technology simultaneously, e.g., hydrogen-powered aircraft. Given the sensitivity of the reliable and continuous performance of HTS cables, any failures, caused by faults, could be catastrophic, if they are not designed appropriately. Thus, fault analysis of superconducting cables is crucial for ensuring their safety, reliability, and stability, and also for characterising the behaviour of HTS cables under fault currents at the design stage. Many investigations have been conducted on the fault characterisation and analysis of HTS cables in the last few years. This paper aims to provide a topical review on all of these conducted studies, and will discuss the current challenges of HTS cables and after that current developments of fault behaviour of HTS cables will be presented, and then we will discuss the future trends and future challenges of superconducting cables regarding their fault performance.

37 citations

Journal ArticleDOI
01 Mar 2022-Energy
TL;DR: Considering the limitation of current-carrying capacity and huge ohmic loss of the conventional copper busbars, the authors presents a novel solution using high-temperature superconductor (HTS) DC busbars for data centers with the ultra-high current carrying capacity and compact size.

20 citations

Journal ArticleDOI
TL;DR: In this article, the authors presented an ac loss numerical study of quasi-isotropic strands fabricated by second generation wires in cryogenic temperatures of 4.2 and 77 K. In order to estimate the ac losses accurately, a scaling relation of critical current density depending on the magnetic field and magnetic field angle with wire is adopted in the model.
Abstract: This paper mainly presents an ac loss numerical study of quasi-isotropic strands fabricated by second generation wires in cryogenic temperatures of 4.2 and 77 K. In order to estimate the ac losses accurately, a scaling relation of critical current density depending on the magnetic field and magnetic field angle with wire is adopted in the model. AC loss contributions, including hysteresis and eddy current losses, are estimated in detail at 5-Hz magnetic field with amplitude range from 0.1 to 7 T. At low fields and 4.2 K temperature, hysteresis losses of quasi-isotropic strands are less than the eddy current losses (which mainly comes from the copper sheath), this situation is very different from the 77 K. Effects of the magnetic field frequency and orientation with a strand on ac losses are also particularly analyzed under different magnetic fields. The numerical results are helpful for overall understanding on ac loss characteristics of quasi-isotropic strands and are also useful for their applications in high magnetic field at low temperatures.

17 citations

Journal ArticleDOI
TL;DR: In this article, a quasi-isotropic superconducting strand (Q-IS) stacked by 2 mm wide REBCO tapes and Cu tapes with geometrical symmetric configuration was developed, and a three dimensional numerical model considering the anisotropic thermal conductivity was built to study the thermal stability of the strand, including minimum quench energy (MQE) and quench propagation velocity (QPV).
Abstract: In order to improve the thermal stability of high-temperature superconducting (HTS) strand, a quasi-isotropic superconducting strand (Q-IS) stacked by 2 mm wide REBCO tapes and Cu tapes with geometrical symmetric configuration were developed, in this paper. A three dimensional (3D) numerical model considering the anisotropic thermal conductivity was built to study the thermal stability of the strand, including minimum quench energy (MQE) and quench propagation velocity (QPV). The temperature distribution in the cross section at different positions along the longitudinal direction of the strand during the quench was obtained as well. Then, a strand was prepared to investigate the thermal stability experimentally. Results show that the Q-IS stacked by REBCO tapes and copper tapes has higher MQE than Q-IS without copper tapes. The results can provide a fundamental analysis for further developing device of high-current electric power transmission with high thermal stability.

16 citations