This study introduces a novel approach to realizing compact high-field superconducting magnets by enabling a closed-loop high temperature superconducting(HTS)coil through magnetization.A circular closed-loop HTS coil ...This study introduces a novel approach to realizing compact high-field superconducting magnets by enabling a closed-loop high temperature superconducting(HTS)coil through magnetization.A circular closed-loop HTS coil is fabricated with a low resistive joint for field cooling magnetization.The HTS coil achieved a trapped field with only a 0.0087%decay in central field over 30 min-utes.More interestingly,the central trapped field of 4.59 T exceeds the initial applied field of 4.5 T,while a peak trapped field of 6 T near the inner edge of the HTS coil,is identified through further numerical investigation.This phenomenon differs from the trapped field distributions observed in HTS bulks and stacks,where the trapped cannot exceed the applied one.Unique distributions of current density and magnetic field are identified as the reason for the trapped field exceeding the applied field.This study offers a new way to develop compact HTS magnets for a range of high-field applications such as superconducting magnetic energy storage(SMES)systems,superconducting machines,Maglev and proposes a viable method for amplifying the field strength beyond that of existing magnetic field source devices.展开更多
A permanent magnet linear synchronous motor （PMLSM） for a high temperature superconducting （HTS） maglev system has been studied, including the motor structure, control strategy, and analysis techniques. Finite ele...A permanent magnet linear synchronous motor （PMLSM） for a high temperature superconducting （HTS） maglev system has been studied, including the motor structure, control strategy, and analysis techniques. Finite element analysis （FEA） of magnetic field is conducted to accurately calculate major motor parameters. Equivalent electrical circuit is used to predict the drive＇s steady-state characteristics, and a phase variable model is applied to predict the dynamic performance. Preliminary experiment with a prototype has been made to verify the theoretical analysis and the HTS-PM synchronous driving technology.展开更多
We present a conceptual configuration of a high-temperature superconducting（HTS）magnet made from REBCO（Re=Rare Earth,B=Barium,C=Copper,O=Oxide）annular plates,called a Bitter-like HTS magnet,which can operate in pe...We present a conceptual configuration of a high-temperature superconducting（HTS）magnet made from REBCO（Re=Rare Earth,B=Barium,C=Copper,O=Oxide）annular plates,called a Bitter-like HTS magnet,which can operate in persistent current mode without joint resistance and can be excited by a flux pump and without current leads and a persistent power supply.An REBCO annular magnet which can generate 1.5 T corresponding to the operating current density 80%of critical current density of the magnet at an operating temperature of65 K is conceptually designed.Then the thermal stability of the magnet is numerically simulated by Comsol software.Whein a piece of RBCO annular plate quenches,the maximum released energy is its stored energy because each REBCO annular plate in the Bitter-like magnet is in parallel.To calculate the stored energy in the REBCO annular plate,the inductance of every annular plate,including self-inductance and mutual inductance,is calculated.Compared with the minimum quench energy（MQE）and stored energy in one REBCO annular plate,the stored energy in one REBCO annular plate is always smaller than the MQE,and the REBCO annular plate will not be damaged even though the stored energy in the REBCO annular plate is fully released,which indicates that this 1.5 T Bitter-like magnet has the property of self-protection.展开更多
基金the support of LNCMICNRS,a member of the European Magnetic Field Laboratory(EMFL).This work is selected by the European Research Council(101077404 SUPERMAN)and funded by UKRI.
文摘This study introduces a novel approach to realizing compact high-field superconducting magnets by enabling a closed-loop high temperature superconducting(HTS)coil through magnetization.A circular closed-loop HTS coil is fabricated with a low resistive joint for field cooling magnetization.The HTS coil achieved a trapped field with only a 0.0087%decay in central field over 30 min-utes.More interestingly,the central trapped field of 4.59 T exceeds the initial applied field of 4.5 T,while a peak trapped field of 6 T near the inner edge of the HTS coil,is identified through further numerical investigation.This phenomenon differs from the trapped field distributions observed in HTS bulks and stacks,where the trapped cannot exceed the applied one.Unique distributions of current density and magnetic field are identified as the reason for the trapped field exceeding the applied field.This study offers a new way to develop compact HTS magnets for a range of high-field applications such as superconducting magnetic energy storage(SMES)systems,superconducting machines,Maglev and proposes a viable method for amplifying the field strength beyond that of existing magnetic field source devices.
文摘A permanent magnet linear synchronous motor （PMLSM） for a high temperature superconducting （HTS） maglev system has been studied, including the motor structure, control strategy, and analysis techniques. Finite element analysis （FEA） of magnetic field is conducted to accurately calculate major motor parameters. Equivalent electrical circuit is used to predict the drive＇s steady-state characteristics, and a phase variable model is applied to predict the dynamic performance. Preliminary experiment with a prototype has been made to verify the theoretical analysis and the HTS-PM synchronous driving technology.
基金Supported by the Fundamental Research Funds for the Central Universities under Grant No 2018MS004
文摘We present a conceptual configuration of a high-temperature superconducting（HTS）magnet made from REBCO（Re=Rare Earth,B=Barium,C=Copper,O=Oxide）annular plates,called a Bitter-like HTS magnet,which can operate in persistent current mode without joint resistance and can be excited by a flux pump and without current leads and a persistent power supply.An REBCO annular magnet which can generate 1.5 T corresponding to the operating current density 80%of critical current density of the magnet at an operating temperature of65 K is conceptually designed.Then the thermal stability of the magnet is numerically simulated by Comsol software.Whein a piece of RBCO annular plate quenches,the maximum released energy is its stored energy because each REBCO annular plate in the Bitter-like magnet is in parallel.To calculate the stored energy in the REBCO annular plate,the inductance of every annular plate,including self-inductance and mutual inductance,is calculated.Compared with the minimum quench energy（MQE）and stored energy in one REBCO annular plate,the stored energy in one REBCO annular plate is always smaller than the MQE,and the REBCO annular plate will not be damaged even though the stored energy in the REBCO annular plate is fully released,which indicates that this 1.5 T Bitter-like magnet has the property of self-protection.
