Article
Engineering, Electrical & Electronic
Mark D. Ainslie, Loic Queval, Ratu C. Mataira, Chris W. Bumby
Summary: This study investigates the frequency dependence of a high-Tc superconducting dynamo and proposes a new explanation for the observed phenomenon. Numerical analysis utilizing a finite-element model is used to study the impact of rotation frequency and temperature on the dynamo's open-circuit DC voltage.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2021)
Article
Energy & Fuels
Giacomo Russo, Antonio Morandi
Summary: High Temperature Superconducting (HTS) dynamo flux pumps are a promising alternative to metal current leads for energization and the persistent current mode operation of high current DC superconducting magnet systems. This paper evaluates and compares the performance of several commercial HTS tapes used for flux pumping purposes through numerical simulation, and investigates the dependence of the flux pump's performance on the operating temperatures.
Article
Engineering, Electrical & Electronic
Alexandre Arsenault, Frederic Sirois, Francesco Grilli
Summary: The H-phi formulation is an effective method for modeling electromagnetic phenomena involving superconducting materials, showing better performance in computation compared to the H formulation by significantly reducing degrees of freedom and computation times. The accuracy of magnetic fields obtained with both formulations are similar, but the computational benefits of the H-phi formulation outweigh its complexity.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2021)
Article
Engineering, Electrical & Electronic
Alexandre Arsenault, Bruno de Sousa Alves, Frederic Sirois
Summary: This article introduces a method to efficiently and accurately solve for the magnetic field surrounding superconducting domains using a magnetic scalar potential and the H-formulation in the COMSOL Multiphysics environment. By applying thin cuts to create a discontinuity in phi in nonconducting domains, the simply connected requirement for Ampere's law can be satisfied. Experimental results show that the H-phi-formulation can be up to seven times faster than the standard H-formulation in certain applications.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2021)
Article
Engineering, Electrical & Electronic
Alexandre Arsenault, Frederic Sirois, Francesco Grilli
Summary: This article presents a method to efficiently simulate superconductors surrounded by magnetic bodies using the H-phi formulation, which significantly reduces computation times compared to the H-formulation, with nearly three times and four times reduction in 2-D and 3-D, respectively. The H-phi formulation is shown to be more accurate and efficient in 2-D compared to the H-A formulation.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2021)
Article
Physics, Applied
Gengyao Li, Chao Li, Ying Xin, Wei Hong, Wenxin Li, Tianhui Yang, Bin Li
Summary: A dynamic modelling method based on the H-formulation and moving mesh has been proposed to simulate the electromagnetic performance of the HTS energy converter accurately. The model's validity has been verified by experimental results and effects of different parameters of the energy converter have been investigated in detail to provide further insight into the design and applications of the device.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Lin Fu, Koichi Matsuda, Boyang Shen, Tim Coombs
Summary: The paper presents updates to the model for a traveling wave HTS electromagnetic flux pump, considering various sources of resistance including joint resistance, superconducting resistance, and dynamic resistance. Experiments were conducted to test the model's fit to the data.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2021)
Article
Engineering, Electrical & Electronic
Lin Fu, Koichi Matsuda, Boyang Shen, Tim Coombs
Summary: In recent years, with the continuous development of High-temperature Superconductor (HTS) technology, the performance of HTS tape has been significantly improved. To use HTS instead of Low-temperature Superconductor (LTS) in MRI applications, the flux pumping method has been investigated.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2021)
Article
Physics, Applied
Pengbo Zhou, Asef Ghabeli, Mark Ainslie, Francesco Grilli
Summary: Flux pumps provide a solution for contactless charging of HTS coils, and understanding the dynamics of the charging process is essential. This study proposes a methodology for coupling HTS coil and flux pump models using an electrical circuit. Validation of the approach shows good agreement with experimental results, and it is suggested to leave a margin between the operating current and the coil's critical current when using flux pumps.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2023)
Article
Acoustics
Wenxiang Ding, Maxime Bavencoffe, Marc Lethiecq
Summary: This paper presents a formulation for developing the dynamic stiffness matrix of a piezoelectric array element with arbitrary boundary conditions. Gorman's superposition method is innovatively utilized to obtain the solutions of the governing equations of motion for piezoelectric materials. The strong form of boundary conditions is satisfied, and the Projection method is adopted for solving the spatial dependence. The results of a piezoelectric array element operating as a transmitter and receiver are validated using the finite element method with COMSOL Multiphysics.
JOURNAL OF SOUND AND VIBRATION
(2023)
Article
Engineering, Electrical & Electronic
Haipeng Zhang, Jiajie Long, Xianhao Li, Ying Xu, Jing Shi, Li Ren, Wentie Yang, Zuoshuai Wang, Meng Chen
Summary: This article proposes a method for measuring the residual flux of ferromagnets using magnetic sensors and a finite-element model to mitigate the surge of inrush current caused by residual flux when the power transformer is connected to the power grid. The experimental results confirm the accuracy and applicability of this method for measuring nonuniform residual flux and determining its direction, offering significant advantages compared to existing methods.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2023)
Article
Computer Science, Interdisciplinary Applications
Liang Wang, Xue Zhang, Sheng Zhang, Stefano Tinti
Summary: A novel mathematical programming formulation is developed for the dynamic analysis of saturated porous media, which can be solved using modern optimization engines. The proposed computational scheme is verified against typical benchmarks and further implemented into the PFEM framework to address issues caused by large deformations. Several case studies illustrate the capability of the method for analyzing porous media with large deformations.
COMPUTERS AND GEOTECHNICS
(2021)
Article
Computer Science, Interdisciplinary Applications
Christopher G. Albert, Patrick Lainer, Oszkar Biro
Summary: This paper presents a numerical method for solving three-dimensional linear magnetostatic problems by embedding the geometry into a symmetric domain and using Fourier expansion. The developed method allows for a decoupled set of two-dimensional problems, reducing computational complexity and improving efficiency. The approach has important applications in analyzing magnetic plasma confinement devices.
COMPUTER PHYSICS COMMUNICATIONS
(2022)
Article
Physics, Applied
Kai Zhang, Mark Ainslie, Marco Calvi, Ryota Kinjo, Thomas Schmidt
Summary: The development of a new hard X-ray beamline I-TOMCAT equipped with a 1 m long short-period bulk high-temperature superconductor undulator (BHTSU) is planned for the Swiss Light Source at the Paul Scherrer Institute. The key challenge lies in designing a 1 m long BHTSU, particularly in simulating the magnetization currents inside 200 staggered-array bulk superconductors. Simplifying the electromagnetic model by retaining five periods from both ends has been proposed to reduce the number of degrees of freedom to millions.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2021)
Article
Physics, Applied
A. Morandi, G. Russo, M. Fabbri, L. Soldati
Summary: This paper investigates the energy behavior of rotating flux pumps and finds that induced currents interact with the rotating magnet(s), converting a significant part of mechanical power into Joule heating. The study also explores the operational limits of the flux pump, showing that generator operation can only be achieved within a restricted range of current and voltage, with maximum power transfer and efficiency reached in the middle of the generator range.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2022)
Article
Automation & Control Systems
Jianzhao Geng, Rodney A. Badcock, Chris W. Bumby
Summary: A novel mechanism of inductively energizing closed-loop HTS dc magnets has been discovered, which eliminates the need for electronic power supplies and bulky current leads. This new approach reduces the footprint and power demand of HTS magnet systems, opening up new opportunities for the technology's applications.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Yujia Zhai, Jiawei Zhang, Ziwei Tan, Xinyi Liu, Boyang Shen, Tim Coombs, Ping Liu, Shoudao Huang
Summary: This paper introduces the method of predicting wind farm output power to improve the scheduling ability of wind power generation, and optimizes the control strategy of SMES by introducing sliding mode variable structure control, thereby improving the stability and controllability of wind power output.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2021)
Article
Engineering, Electrical & Electronic
Yavuz Ozturk, Boyang Shen, Richard Williams, James Gawith, Jiabin Yang, Jun Ma, Adrian Carpenter, Tim Coombs
Summary: Magnetic Resonance Imaging is crucial for monitoring lipid-rich tissues and the musculoskeletal system, requiring a huge, homogeneous magnetic field. Superconductors are essential for creating such fields, with high critical temperature superconductors showing advantages in field strength and cost reduction. The technology aims for compactness and mobility in MRI machines, with HTS tapes enabling smaller and portable scanners for patients.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2021)
Article
Engineering, Electrical & Electronic
Haigening Wei, Boyang Shen, Adil Shah, Jiabin Yang, Luning Hao, Mengyuan Tian, Jintao Hu, Ismail Patel, Yavuz Ozturk, Tim Coombs
Summary: This paper proposes a new 2D model for superconducting axial field machines and compares its results with other formulations, allowing for more accurate analysis of superconducting machine performance.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2022)
Article
Engineering, Electrical & Electronic
Mengyuan Tian, Jiabin Yang, Boyang Shen, Yavuz Ozturk, Jun Ma, Chao Li, Jintao Hu, Haigening Wei, Junshi Li, Tim Coombs
Summary: This paper presents an AC loss study of CORC cables with several different superconducting layer thicknesses utilizing a software suite named COMSOL Multiphysics and the finite-element method (FEM) solved by the three-dimensional (3-D) H-formulation. By implementing FEM simulations, the cases of increasing the degree of freedom of superconducting layers have been considered, and the AC losses of a single layer CORC cable model with three tapes mounted around the core have been calculated and analyzed for different layer thicknesses. Simulation results are verified with experimental results measured in previous literature.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2021)
Article
Engineering, Electrical & Electronic
Boyang Shen, Jiabin Yang, Mengyuan Tian, Tim Coombs
Summary: This paper evaluates the loss level of saturated iron-core FCLs (SI-SFCLs) in a VSC-based distribution grid and analyzes the power dissipation during short-circuit, demonstrating the potential of reaching tens of kilowatts. The study provides helpful guidance for the design of SI-SFCLs.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2021)
Article
Engineering, Electrical & Electronic
Yaru Sheng, Chao Li, Hanru Jia, Bin Liu, Bin Li, Tim A. Coombs
Summary: The rapid development of PMSG-based offshore wind farms in the past decade has led to the proposal of improved fault ride-through (FRT) schemes to prevent disconnections during faults. In this study, the use of a resistive SFCL is proposed to enhance FRT capabilities by reducing energy consumption during faults and improving the performance of the Chopper circuit. Simulation results using PSCAD/EMTDC software validate the feasibility of the proposed scheme.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2021)
Article
Engineering, Electrical & Electronic
Chao Li, Shengjie Wang, Hanru Jia, Jiawei He, Bin Li, Tim A. Coombs
Summary: Flux pumps, particularly the transformer-rectifier flux pump, have drawn increasing attention for their ability to wirelessly energize superconducting coil and minimize power loss. This paper investigates the impact of saturated transformer on the working performance of flux pump, with analysis and comparison on how the saturation degree affects the pump. Simulation tests using Simulink software package are conducted to validate the analysis.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2021)
Article
Engineering, Electrical & Electronic
Ismail Patel, Adil Shah, Yavuz Ozturk, Boyang Shen, Luning Hao, Jiabin Yang, Jintao Hu, Menguan Tian, Tim Coombs
Summary: This paper proposes a novel approach to modeling HTS transformer-rectifier flux pumps, which can charge HTS magnetic loads without the need for bulky current leads or expensive cryogenic requirements. The model was built in MATLAB/Simulink and the simulation results show that the system can quickly charge the HTS load under given parameters.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2022)
Article
Engineering, Electrical & Electronic
Luning Hao, Ismail Patel, Jiabin Yang, Jintao Hu, Adil Shah, Haigening Wei, Mengyuan Tian, Qi Wang, Boyang Shen, Tim Coombs
Summary: This paper focuses on the field cancelling effect of the Roebel tape and its impact on AC losses. By optimizing the structure parameters, an optimum solution is obtained. This research provides a better understanding of the Roebel tape and serves as a reference for future design and application.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2022)
Article
Physics, Applied
Luning Hao, Fangliang Dong, Jiabin Yang, Ismail Patel, Haigening Wei, Qi Wang, Jintao Hu, Mengyuan Tian, Adil Shah, Boyang Shen, Tim Coombs
Summary: Magnetic switches, commonly used in charging HTS-coated conductor magnets, can cause a critical current reduction due to the enhanced self-field of the HTS tape by iron cores. In this study, we present analytical approximations to calculate the self-field distribution and verify the results using experiments and 3D finite element method models. The solutions can determine the critical current reduction quickly and accurately, and simplify the design process of magnetic switches.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Luning Hao, Jintao Hu, Haigening Wei, Qi Wang, Mengyuan Tian, Ismail Patel, Adil Shah, Tim Coombs
Summary: The Roebel tape is a high-temperature superconducting wire with a multi-layer structure. It can effectively reduce AC losses by canceling the magnetic fields between adjacent layers. The study focuses on the AC losses of the Roebel tape and suggests increasing the distance between layer pairs or using double-layer stacks to reduce losses and improve current density.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2023)
Article
Engineering, Electrical & Electronic
J. Ma, J. Hu, H. Xiao, X. Luo, Y. Xia, J. Geng, T. A. Coombs
Summary: The dynamic resistance effect introduces dissipative loss to type-II high Tc superconductors, but can also be effectively exploited in some cases. A high temperature superconducting (HTS) power switch, based on the dynamic resistance effect, has been developed and is a key component in the HTS transformer-rectifier flux pump (TRFP).
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2023)
Article
Engineering, Electrical & Electronic
Haigening Wei, Qi Wang, Luning Hao, Jintao Hu, Mengyuan Tian, Ismail Patel, Adil Shah, Tim Coombs
Summary: This research investigates substitutions for wider tapes in superconducting electrical machines. Different stack architectures and substrate materials are tested for their magnetizing effect using pulse field magnetization. Sectioned stacks are tested in a modified synchronous machine under liquid nitrogen conditions to explore the characteristics of trapped flux, magnetization, and demagnetization.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2023)
Article
Physics, Applied
Qi Wang, Hongye Zhang, Luning Hao, Jintao Hu, Haigening Wei, Ismail Patel, Adil Shah, Tim Coombs
Summary: This research presents a comprehensive and innovative method to investigate the magnetisation and cross-field demagnetisation behavior of high-temperature superconducting coated conductors in practical superconducting machines. The study introduces several novel contributions, including the exploration of harmonics interaction in a real electric machine environment involving coated conductors, and the investigation of magnetisation losses occurring in various layers. The research outcomes are anticipated to contribute to the advancement of superconducting machine technology.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2023)
