Pub Date : 2024-10-03DOI: 10.1109/TASC.2024.3473850
Bruno de Sousa Alves;Alexandre Arsenault;Frédéric Sirois
This article presents a finite-element thin-shell (TS) model and its application to 2-D electromagnetic problems involving superconducting tapes in COMSOL Multiphysics. The magnetic scalar potential ( $phi$ ) is the state variable in nonconducting regions surrounding of the tapes, which are represented as zero thickness objects in the calculus domain. Inside the tapes, an auxiliary 1-D problem formulated in terms of the tangential components of the magnetic field ( $H$ ) takes into account the physics across their thickness. The final finite-element system of equations includes both the 2-D and 1-D discretized equations, which are solved simultaneously in a fully coupled manner and transparently for the user. The use of thin cuts is required to impose transport currents in the tapes. This procedure allows the simulation of problems comprising superconducting tapes in any geometrical configuration. We demonstrate that both the normal and tangential fields agree well with reference solutions obtained with the widely used $T$ - $A$ -formulation and with the more standard $H$ - and $H$ - $phi$ -formulations with a full 2-D discretization of the tapes. The proposed $H$ - $phi$ TS model estimates ac losses accurately while speeding up simulations. This makes this model ideal for simulating large-scale superconducting devices in 2-D, particularly when they comprise compact arrangements of high-temperature superconductor tapes carrying antiparallel currents.
{"title":"2-D Thin-Shell Model Based on the $H$-$phi$-Formulation for Modeling HTS Tapes in COMSOL Multiphysics","authors":"Bruno de Sousa Alves;Alexandre Arsenault;Frédéric Sirois","doi":"10.1109/TASC.2024.3473850","DOIUrl":"https://doi.org/10.1109/TASC.2024.3473850","url":null,"abstract":"This article presents a finite-element thin-shell (TS) model and its application to 2-D electromagnetic problems involving superconducting tapes in COMSOL Multiphysics. The magnetic scalar potential (\u0000<inline-formula><tex-math>$phi$</tex-math></inline-formula>\u0000) is the state variable in nonconducting regions surrounding of the tapes, which are represented as zero thickness objects in the calculus domain. Inside the tapes, an auxiliary 1-D problem formulated in terms of the tangential components of the magnetic field (\u0000<inline-formula><tex-math>$H$</tex-math></inline-formula>\u0000) takes into account the physics across their thickness. The final finite-element system of equations includes both the 2-D and 1-D discretized equations, which are solved simultaneously in a fully coupled manner and transparently for the user. The use of thin cuts is required to impose transport currents in the tapes. This procedure allows the simulation of problems comprising superconducting tapes in any geometrical configuration. We demonstrate that both the normal and tangential fields agree well with reference solutions obtained with the widely used \u0000<inline-formula><tex-math>$T$</tex-math></inline-formula>\u0000-\u0000<inline-formula><tex-math>$A$</tex-math></inline-formula>\u0000-formulation and with the more standard \u0000<inline-formula><tex-math>$H$</tex-math></inline-formula>\u0000- and \u0000<inline-formula><tex-math>$H$</tex-math></inline-formula>\u0000-\u0000<inline-formula><tex-math>$phi$</tex-math></inline-formula>\u0000-formulations with a full 2-D discretization of the tapes. The proposed \u0000<inline-formula><tex-math>$H$</tex-math></inline-formula>\u0000-\u0000<inline-formula><tex-math>$phi$</tex-math></inline-formula>\u0000 TS model estimates ac losses accurately while speeding up simulations. This makes this model ideal for simulating large-scale superconducting devices in 2-D, particularly when they comprise compact arrangements of high-temperature superconductor tapes carrying antiparallel currents.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"34 9","pages":"1-10"},"PeriodicalIF":1.7,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The electromagnetic calculations of large-size high-temperature superconducting (HTS) toroidal D-shaped magnets present structural complexity and modeling difficulties, resulting in high complexity in the evaluation of the energy storage, critical current and central magnetic field, which pose significant challenges to the electromagnetic design. This paper established an analytical calculation model for the inductance and magnetic field of the toroidal D-shaped HTS magnet under the assumptions of static magnetic field and current distribution, and developed the discrete method and accelerate calculation further through integral transformations. The discrete method was compared and validated against the finite element analysis (FEM) method and 3D T-A homogenization method. The results indicate that the discrepancies in inductance and parallel fields between the discrete analytical method and the 3D T-A are less than 3%, with errors in perpendicular fields within 20%, and exhibit a computational speed 4 to 6 orders of magnitude faster than FEM. The larger error in the perpendicular field is due to the non-uniform superconducting current distribution, which occurs mainly inside the magnet. This approach can be applied to the preliminary evaluation of performance parameters such as stored energy and critical current in toroidal HTS magnets, thereby enhancing the efficiency of electromagnetic design.
大尺寸高温超导（HTS）环形 D 型磁体的电磁计算存在结构复杂、建模困难等问题，导致储能、临界电流和中心磁场的评估复杂度较高，给电磁设计带来了巨大挑战。本文在静磁场和电流分布的假设条件下，建立了环形 D 型 HTS 磁体电感和磁场的分析计算模型，并发展了离散法，通过积分变换进一步加速计算。离散方法与有限元分析（FEM）方法和三维 T-A 匀化方法进行了比较和验证。结果表明，离散分析法与三维 T-A 在电感和平行场方面的差异小于 3%，垂直场误差在 20% 以内，计算速度比有限元分析法快 4 到 6 个数量级。垂直场误差较大的原因是超导电流分布不均匀，主要发生在磁体内部。这种方法可用于环形 HTS 磁体的储能和临界电流等性能参数的初步评估，从而提高电磁设计的效率。
{"title":"Analytical Model for Magnetic Field and Inductance of Toroidal D-Shaped HTS Magnet","authors":"Yifeng Qiu;Li Ren;Ying Xu;Zhixing Yang;Hao Li;Yuejin Tang","doi":"10.1109/TASC.2024.3472457","DOIUrl":"https://doi.org/10.1109/TASC.2024.3472457","url":null,"abstract":"The electromagnetic calculations of large-size high-temperature superconducting (HTS) toroidal D-shaped magnets present structural complexity and modeling difficulties, resulting in high complexity in the evaluation of the energy storage, critical current and central magnetic field, which pose significant challenges to the electromagnetic design. This paper established an analytical calculation model for the inductance and magnetic field of the toroidal D-shaped HTS magnet under the assumptions of static magnetic field and current distribution, and developed the discrete method and accelerate calculation further through integral transformations. The discrete method was compared and validated against the finite element analysis (FEM) method and 3D T-A homogenization method. The results indicate that the discrepancies in inductance and parallel fields between the discrete analytical method and the 3D T-A are less than 3%, with errors in perpendicular fields within 20%, and exhibit a computational speed 4 to 6 orders of magnitude faster than FEM. The larger error in the perpendicular field is due to the non-uniform superconducting current distribution, which occurs mainly inside the magnet. This approach can be applied to the preliminary evaluation of performance parameters such as stored energy and critical current in toroidal HTS magnets, thereby enhancing the efficiency of electromagnetic design.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"34 8","pages":"1-6"},"PeriodicalIF":1.7,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142555078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-30DOI: 10.1109/TASC.2024.3468068
Sen Wang;Haiyang Wang;Chong Tang;Lei Wang;Yuqin Zhu;Hao Liu;Sixing Wang
The small effect of parameter variations on the sliding mode observer (SMO) and its robustness have been widely used in position observation of permanent magnet synchronous motors (PMSM). However, when observing the position of a permanent magnet synchronous motor using SMO, there are problems of chattering and slow observation speed. Therefore, in order to improve the anti-interference performance and control accuracy of the PMSM control system. Firstly, an integral nonsingular fast terminal sliding mode observer is studied to improve its observation speed. Secondly, in order to further reduce the chattering of the nonsingular fast terminal sliding mode observer, an adaptive sliding mode control law is designed, which is an adaptive nonsingular fast terminal sliding mode observer (ANFTSMO). An adaptive function related to the sliding surface is established before the switching function to adjust the amplitude of the switching function. Then, the closed-loop system is rigorously analyzed by using Lyapunov theory, and the stability of the observer is proved. Finally, the analysis and verification are carried out on the 1KW PMSM experimental platform, and the position feedback estimation of the studied observer is more accurate under the same torque. Therefore, PMSM has better control performance, stronger robustness and better system stability.
{"title":"Sensorless Control Strategy for Permanent Magnet Synchronous Motor Based on Adaptive Non-Singular Fast Terminal Sliding Mode Observer","authors":"Sen Wang;Haiyang Wang;Chong Tang;Lei Wang;Yuqin Zhu;Hao Liu;Sixing Wang","doi":"10.1109/TASC.2024.3468068","DOIUrl":"https://doi.org/10.1109/TASC.2024.3468068","url":null,"abstract":"The small effect of parameter variations on the sliding mode observer (SMO) and its robustness have been widely used in position observation of permanent magnet synchronous motors (PMSM). However, when observing the position of a permanent magnet synchronous motor using SMO, there are problems of chattering and slow observation speed. Therefore, in order to improve the anti-interference performance and control accuracy of the PMSM control system. Firstly, an integral nonsingular fast terminal sliding mode observer is studied to improve its observation speed. Secondly, in order to further reduce the chattering of the nonsingular fast terminal sliding mode observer, an adaptive sliding mode control law is designed, which is an adaptive nonsingular fast terminal sliding mode observer (ANFTSMO). An adaptive function related to the sliding surface is established before the switching function to adjust the amplitude of the switching function. Then, the closed-loop system is rigorously analyzed by using Lyapunov theory, and the stability of the observer is proved. Finally, the analysis and verification are carried out on the 1KW PMSM experimental platform, and the position feedback estimation of the studied observer is more accurate under the same torque. Therefore, PMSM has better control performance, stronger robustness and better system stability.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"34 8","pages":"1-5"},"PeriodicalIF":1.7,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142430728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-27DOI: 10.1109/TASC.2024.3465749
{"title":"IEEE Foundation: Reflecting on 50 Years of Impact","authors":"","doi":"10.1109/TASC.2024.3465749","DOIUrl":"https://doi.org/10.1109/TASC.2024.3465749","url":null,"abstract":"","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"34 7","pages":"1-1"},"PeriodicalIF":1.7,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10697290","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142328420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-27DOI: 10.1109/TASC.2024.3456977
{"title":"IEEE Transactions on Applied Superconductivity Information for Authors","authors":"","doi":"10.1109/TASC.2024.3456977","DOIUrl":"https://doi.org/10.1109/TASC.2024.3456977","url":null,"abstract":"","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"34 7","pages":"C4-C4"},"PeriodicalIF":1.7,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10697312","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142329323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-27DOI: 10.1109/TASC.2024.3469871
Ziqing Meng;Yinshun Wang;Junhua Cheng;Jiawen Wang;Ye He;Wei Pi
High temperature superconducting (HTS) direct current (DC) cables have recently gained interest and are being considered for some applications because of their intrinsic zero resistance and high current density. However, due to the unavoidable harmonic currents in practical DC transmission systems, the issues of AC loss and dynamic resistance of HTS DC cables have to be paid much attention. Besides, for a high voltage transmission line with a length of more than several kilometers, the flux flow and contacting resistances should be calculated simultaneously. In this paper, E-I power law instead of the critical state model (CSM) is adopted and temperature variation caused by cable length are considered in analyzing the characteristics of HTS DC cable. A 1 km/5 kA HTS DC cable based on the principle of uniform current is designed considering three types of resistances comprehensively, which is significant to the development and operation of HTS DC cables toward practical long transmission distance.
{"title":"Influence of Flux-Flow and Terminal Contacting as Well as Dynamic Resistances Due to Ripple Current on Performance of the km-Class HTS DC Cable","authors":"Ziqing Meng;Yinshun Wang;Junhua Cheng;Jiawen Wang;Ye He;Wei Pi","doi":"10.1109/TASC.2024.3469871","DOIUrl":"https://doi.org/10.1109/TASC.2024.3469871","url":null,"abstract":"High temperature superconducting (HTS) direct current (DC) cables have recently gained interest and are being considered for some applications because of their intrinsic zero resistance and high current density. However, due to the unavoidable harmonic currents in practical DC transmission systems, the issues of AC loss and dynamic resistance of HTS DC cables have to be paid much attention. Besides, for a high voltage transmission line with a length of more than several kilometers, the flux flow and contacting resistances should be calculated simultaneously. In this paper, E-I power law instead of the critical state model (CSM) is adopted and temperature variation caused by cable length are considered in analyzing the characteristics of HTS DC cable. A 1 km/5 kA HTS DC cable based on the principle of uniform current is designed considering three types of resistances comprehensively, which is significant to the development and operation of HTS DC cables toward practical long transmission distance.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"34 8","pages":"1-5"},"PeriodicalIF":1.7,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142579176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-27DOI: 10.1109/TASC.2024.3469282
Bo Zheng;Wei Xie;Yuhao Liu;Xiyu Zhu;Xue Ming;Yuhang Zhang;Hai-Hu Wen
Using a solid-state reaction method starting with Nb and Nb 6 Sn 5 powders, we have synthesized bulk Nb 3 Sn samples with uniformly distributed Sn contents of 24%, 25%, and 25.6%. Among them, the sample with Sn content = 25% may go through a structural phase transition from cubic to tetragonal structure at a low temperature of 43 K. The X-ray diffraction and resistivity measurements show systematic changes in samples with three different Sn contents. We found that the highest Tc is located in the sample with exactly stoichiometric composition (Sn content = 25%), which may be due to the tetragonal structure. In addition, properties of flux jumps under various physical conditions in Nb 3 Sn materials are investigated through magnetization measurements, and significant suppression to flux jumps was found in samples with slightly higher Sn content (Sn content ≈25.6%) and better compactness and grain refinement.
{"title":"Optimization of Magnetic Stability in Nb3Sn Materials Near Stoichiometric Composition","authors":"Bo Zheng;Wei Xie;Yuhao Liu;Xiyu Zhu;Xue Ming;Yuhang Zhang;Hai-Hu Wen","doi":"10.1109/TASC.2024.3469282","DOIUrl":"https://doi.org/10.1109/TASC.2024.3469282","url":null,"abstract":"Using a solid-state reaction method starting with Nb and Nb\u0000<sub>6</sub>\u0000Sn\u0000<sub>5</sub>\u0000 powders, we have synthesized bulk Nb\u0000<sub>3</sub>\u0000Sn samples with uniformly distributed Sn contents of 24%, 25%, and 25.6%. Among them, the sample with Sn content = 25% may go through a structural phase transition from cubic to tetragonal structure at a low temperature of 43 K. The X-ray diffraction and resistivity measurements show systematic changes in samples with three different Sn contents. We found that the highest \u0000<italic>T<sub>c</sub></i>\u0000 is located in the sample with exactly stoichiometric composition (Sn content = 25%), which may be due to the tetragonal structure. In addition, properties of flux jumps under various physical conditions in Nb\u0000<sub>3</sub>\u0000Sn materials are investigated through magnetization measurements, and significant suppression to flux jumps was found in samples with slightly higher Sn content (Sn content ≈25.6%) and better compactness and grain refinement.","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"34 9","pages":"1-10"},"PeriodicalIF":1.7,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142517896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-27DOI: 10.1109/TASC.2024.3465751
{"title":"TechRxiv: Share Your Preprint Research with the World!","authors":"","doi":"10.1109/TASC.2024.3465751","DOIUrl":"https://doi.org/10.1109/TASC.2024.3465751","url":null,"abstract":"","PeriodicalId":13104,"journal":{"name":"IEEE Transactions on Applied Superconductivity","volume":"34 7","pages":"1-1"},"PeriodicalIF":1.7,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10697314","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142328389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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