Properties of High Temperature Superconducting Magnet With Optimized Air Gap Between Pancake Windings

Large-scale complex needs high performance SMES system with 5 kA-level current carrying and kA/s current ramping rate (such as particle accelerator complex), the inductance of which should be as small as possible (<<1H) to reduce the terminal voltage and realize ideal energy evacuation. This paper introduces the world’s first application of double pancake (DP) coil with CORC cable, which can be a unit of MJ-level SMES system with a total inductance of 125 mH and 4 kA current carrying (@30 K, 4 T). The combination of low inductance and high current capacity guarantee the safety during kA/s operating condition. The CORC wound with highly anisotropic YBCO tape can realize quasi-isotropy with critical properties. The performance of the CORC with 11 layers and 3 tapes in each layer has been fully validated with excitation test at 77 K and the critical current can reach 2906 A@ 77 K, self-field. The skeleton of the DP coil is specially designed with semi-circular spiral groove and the climbing-layer area is supported by two symmetrical blocks, which can provide reasonable support to the CORC cable. The measured critical current of DP coil can realize 1750 A at 77 K (theoretical value is 1800 A). It means that the the coil winding method is feasible to avoid performance degradation during winding. The DP coil based on CORC cable is fully suitable for the SMES system which needs to realize ~4 kA current carrying and fast energy conversion. It also provides a good practice for the engineering application of CORC cable.

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Research on a novel HTS double pancake coil based on CORC: used for kA-level SMES of accelerator

Li¹,

Zheng²,

Sheng³

et al. 2022

“…The literature presents many optimization studies of the superconducting electrical transformer, electrical machines, and magnets [28][29][30][31][32][33][34]. In [28], the authors proposed an optimal BSCCO superconducting winding geometry for the HTS electrical transformer.…”

Section: Introductionmentioning

confidence: 99%

“…The material used to make the superconducting winding was Bi-2223. In [30], Kim et al proposed an optimal distance between the gaps of an HTS-Magnet. This research objective was to maximize the central magnetic field created by the BSCCO-2223 superconducting winding.…”

Section: Introductionmentioning

confidence: 99%

Multi-objective optimization for the superconducting bias coil of a saturated iron core fault current limiter using the T-A formulation

Santos

Sass

Sotelo

et al. 2021

The short-circuit levels have increased considerably in transmission and distribution systems in the last years. Fault current limiter (FCL) devices are a potential solution to this problem. Among several FCL topologies, this group has good experience in the use of superconducting fault current limiters (SFCL) to reduce the electrical current during short-circuits. The literature also presents studies of the saturated iron core superconducting fault current limiter (SIC-SFCL) topology employing mathematical modeling and prototypes design. Some of them have shown promising results, including the construction of pilot prototypes in medium and high voltage substations. The SIC-SFCL simulation studies presented optimal topologies that reduce the amount of ferromagnetic material used in the core and represent well the behavior of this limiter. The finite element method and the finite element analysis are suitable to model the SIC-SFCL. However, a more detailed study focusing on the optimization of the DC bias superconducting coil of the SIC-SFCL has not been presented in the literature yet. In this context, this work proposes a multi-objective optimization method using the Nelder–Mead algorithm to find an optimal geometry for the superconducting coil. In this optimization, the objectives functions are: to maximize the critical current density in the high-temperature superconductor (HTS), minimize the voltage drop in the copper winding, minimize the current through the DC biased superconducting winding, and minimize the price of the HTS superconducting winding. Before implementing the multi-objective optimization algorithm, we have tested a non-superconducting saturated iron core prototype and used the results to validate the simulation models. After that, we have replaced the DC copper winding with an HTS coil in the simulations and initiate the optimization process. Results show that constructing the DC bias superconducting coil using the minimum possible fill factor might not be the best choice.

“…In addition, inserting an air gap between single pancake coils can also optimize the SMES magnet. For example, inserting a fixed air gap in a conventional superconducting magnet could increase the central magnetic field and spontaneously increase the critical current [29], while, inserting unequal gaps in a single pan-cake coil could maximize the central magnetic field and thus the single pancake coil can be optimized with a wider area to improve the uniformity of the magnetic field [30].…”

Section: Introductionmentioning

confidence: 99%

Intelligent design of large-size HTS magnets for SMES and high-field applications: using a self-programmed GUI tool

Chen

Pang

Gou

et al. 2021

Different from many superconducting magnet designs based on the analytical algorithm and finite element method (FEM), this article presents an intelligent design of the SMES and high-field magnet using the self-programmed graphical user interface (GUI). As the important basis, the analytical solutions of SMES magnet are developed for calculating the magnetic field, inductance and critical current, whose accuracies are also verified by the experiment. Then, the analytical solutions are merged into the GUI tool with multi-window interface based on the MATLAB. The new platform is built to offer scientists and engineers a smart tool to design and optimize SMES magnets to reach the maximum energy capacity. After the structural optimization of a MJ-class SMES magnet, the critical current and energy capacity improve by 20.46% and 38.67%, respectively. Compared to previous superconducting magnet designs, this new platform for the SMES and high-field magnet design has the advantages of diverse HTS tape/magnet structure selections, user-friendly interface, automatic optimization, and fast speed.