High temperature Superconducting Magnetic Energy Storage(SMES) systems can exchange energy with substantial renewable power grids in a small period of time with very high efficiency. Because of this distinctive featur...High temperature Superconducting Magnetic Energy Storage(SMES) systems can exchange energy with substantial renewable power grids in a small period of time with very high efficiency. Because of this distinctive feature, they store the abundant wind power when the power network is congested and release the energy back to the system when there is no congestion. However, considering the cost and lifespan of SMES systems, there is an urgent demand to conduct a cost-benefit analysis to justify its role in smart grid development. This study explores the application and performs economic analysis of a 5 MJ SMES in a practical renewable power system in China based on the PSCAD/EMTDC software. An optimal location of SMES in Zhangbei wind farm is presented using real power transmission parameters. The stabilities of the renewable power grid with and without SMES are discussed. In addition, a financial feasibility study is conducted by comparing the cost and the savings from wind power curtailment of deploying SMES and battery. The economic analysis tries to find the balance between SMES investment cost and wind farm operation cost by using real data over a calendar year. The technical analysis can help guide the optimal allocation of SMES for compensating power system instability with substantial wind power. Further, the economic analysis provides a useful indication of its practical application feasibility to fight the balance between cost and benefit.展开更多
With the increasing demand for high power density,and to meet extreme working conditions,research has been focused on inves-tigating the performance of power electronics devices at cryogenic temperatures.The aim of th...With the increasing demand for high power density,and to meet extreme working conditions,research has been focused on inves-tigating the performance of power electronics devices at cryogenic temperatures.The aim of this paper is to review the performance of power semiconductor devices,passive components,gate drivers,sensors,and eventually power electronics converters at cryogenic temperatures.By comparing the physical properties of semiconductor materials and the electrical performance of commercial power semiconductor devices,silicon carbide switches show obvious disadvantages due to the increased on-resistance and switching time at cryogenic temperature.In contrast,silicon and gallium nitride devices exhibit improved performance when tem-perature is decreased.The performance ceiling of power semiconductor devices can be influenced by gate drivers,within which the commercial alternatives show deteriorated performance at cryogenic temperature compared to room temperature.Moreover,options for voltage and current sense in cryogenic environments are justified.Based on the cryogenic performance of the various components afore-discussed,this paper ends by presenting an overview of the published converter,which are either partially or fully tested in a cryogenic environment.展开更多
Second generation(2G)high-temperature superconductor(HTS)(RE)Ba2Cu3Ox(REBCO)shows a great potential in building high field magnets beyond 23.5 T.The electromagnetic modelling is vital for the design of HTS magnet,howe...Second generation(2G)high-temperature superconductor(HTS)(RE)Ba2Cu3Ox(REBCO)shows a great potential in building high field magnets beyond 23.5 T.The electromagnetic modelling is vital for the design of HTS magnet,however,this always suffers the challenge of huge computation for high field magnets with large number of turns.This study presents a novel electromagnetic modelling based on T-A formulation for REBCO magnets with thousands of turns.An equivalent turn method is proposed to reduce the number of turns in calculation,so that the computation cost can be reduced significantly,and meanwhile the key electromagnetic behaviour of HTS magnet can be simulated with enough accuracy.The ramping operation of a fully HTS magnet with 12,000 turns are analysed using both the original T-A model with actual turns and improved T-A model with equivalent turns.The two models show a good agreement on the key electromagnetic behaviours of the magnet:distribution of current density,magnetic fields,screen current induced field and magnetisation loss,so that this improved T-A model using equivalent turns is validated.The T-A modelling of REBCO magnet is a powerful tool for the electromagnetic analysis of industry-scale high field magnets.展开更多
基金funded by the National Key Research and Development Plan,Energy Storage Technology of 10MW Level Redox Battery(2017YFB0903504)China State Grid Corporation science and technology project(DG71-16-002,DG83-17-002)the international cooperation project between China and United Kingdom,RAEng Newton Research Collaboration Programme of UK/1415134
文摘High temperature Superconducting Magnetic Energy Storage(SMES) systems can exchange energy with substantial renewable power grids in a small period of time with very high efficiency. Because of this distinctive feature, they store the abundant wind power when the power network is congested and release the energy back to the system when there is no congestion. However, considering the cost and lifespan of SMES systems, there is an urgent demand to conduct a cost-benefit analysis to justify its role in smart grid development. This study explores the application and performs economic analysis of a 5 MJ SMES in a practical renewable power system in China based on the PSCAD/EMTDC software. An optimal location of SMES in Zhangbei wind farm is presented using real power transmission parameters. The stabilities of the renewable power grid with and without SMES are discussed. In addition, a financial feasibility study is conducted by comparing the cost and the savings from wind power curtailment of deploying SMES and battery. The economic analysis tries to find the balance between SMES investment cost and wind farm operation cost by using real data over a calendar year. The technical analysis can help guide the optimal allocation of SMES for compensating power system instability with substantial wind power. Further, the economic analysis provides a useful indication of its practical application feasibility to fight the balance between cost and benefit.
文摘With the increasing demand for high power density,and to meet extreme working conditions,research has been focused on inves-tigating the performance of power electronics devices at cryogenic temperatures.The aim of this paper is to review the performance of power semiconductor devices,passive components,gate drivers,sensors,and eventually power electronics converters at cryogenic temperatures.By comparing the physical properties of semiconductor materials and the electrical performance of commercial power semiconductor devices,silicon carbide switches show obvious disadvantages due to the increased on-resistance and switching time at cryogenic temperature.In contrast,silicon and gallium nitride devices exhibit improved performance when tem-perature is decreased.The performance ceiling of power semiconductor devices can be influenced by gate drivers,within which the commercial alternatives show deteriorated performance at cryogenic temperature compared to room temperature.Moreover,options for voltage and current sense in cryogenic environments are justified.Based on the cryogenic performance of the various components afore-discussed,this paper ends by presenting an overview of the published converter,which are either partially or fully tested in a cryogenic environment.
基金the National Natural Science Foundation of China under grant nos.11802036 and 11872195the National High Magnetic Field Laboratory,which was supported by the U.S.National Science Foundation Cooperative Agreement no.DMR-1644779 and the State of Florida.
文摘Second generation(2G)high-temperature superconductor(HTS)(RE)Ba2Cu3Ox(REBCO)shows a great potential in building high field magnets beyond 23.5 T.The electromagnetic modelling is vital for the design of HTS magnet,however,this always suffers the challenge of huge computation for high field magnets with large number of turns.This study presents a novel electromagnetic modelling based on T-A formulation for REBCO magnets with thousands of turns.An equivalent turn method is proposed to reduce the number of turns in calculation,so that the computation cost can be reduced significantly,and meanwhile the key electromagnetic behaviour of HTS magnet can be simulated with enough accuracy.The ramping operation of a fully HTS magnet with 12,000 turns are analysed using both the original T-A model with actual turns and improved T-A model with equivalent turns.The two models show a good agreement on the key electromagnetic behaviours of the magnet:distribution of current density,magnetic fields,screen current induced field and magnetisation loss,so that this improved T-A model using equivalent turns is validated.The T-A modelling of REBCO magnet is a powerful tool for the electromagnetic analysis of industry-scale high field magnets.
