Diffusion bonding of multifilamentary Ag/Bi-2223 （ Bi2 Sr2 Ca2 Cu3Ox ） superconducting tapes has been performed successfally. Three types of joints, namely, with sih,er interlayer （type Ⅰ）, bonded directly （type...Diffusion bonding of multifilamentary Ag/Bi-2223 （ Bi2 Sr2 Ca2 Cu3Ox ） superconducting tapes has been performed successfally. Three types of joints, namely, with sih,er interlayer （type Ⅰ）, bonded directly （type Ⅱ）, with Bi-2212 （BizSr2Ca1 Cu2Ox ） powder interlayer or with Bi-2223 powder interlayer （type Ⅲ） were researched, respectively. The critical currents（ Ic ） of these joints were measured ond microstructures of the joints were evaluated by scanning electron microscope （SEM）. The result shows that type Ⅰ is non-superconducting joint with very low resistance, and type Ⅱ joint and type Ⅲ （with Bi-2212 or Bi-2223 ） joints are both of superconducting property. By comparing, type Ⅱ joint possesses most exceUent superconductivity, type Ⅲ joint with Bi-2223 powder interlayer takes the second place, and type ,任家烈 joint with Bi-2212 powder interlayer is least.展开更多
Bi-2223 precursor powders are prepared by both oxalate co-precipitation(CP) and spray pyrolysis(SP) methods.The influence of fabrication methods on the superconducting properties of Bi-2223 tapes are systematically st...Bi-2223 precursor powders are prepared by both oxalate co-precipitation(CP) and spray pyrolysis(SP) methods.The influence of fabrication methods on the superconducting properties of Bi-2223 tapes are systematically studied. Compared to the CP method, SP powder exhibits spherical particle before calcination and smaller particle size after calcinations with more uniform chemical composition, which leads to a lower reaction temperature during calcination process for Bi-2223 tapes. Meanwhile, the non-superconducting phases in SP powder are more uniformly distributed with smaller particle sizes. These features result in finer homogeneity of critical current in large-length of Bi-2223 tape, higher density of filaments and better texture after heat treatment. Therefore,the SP method could be considered as a better route to prepare precursor powder for large-length Bi-2223 tape fabrication.展开更多
To reduce the production cost of Bi-2223 superconducting tapes, Bi-2223/Ag/Ni tapes were fabricated by the powder-in-tube process. The effect of heat treatment on the microstructure and critical current of the Bi-2223...To reduce the production cost of Bi-2223 superconducting tapes, Bi-2223/Ag/Ni tapes were fabricated by the powder-in-tube process. The effect of heat treatment on the microstructure and critical current of the Bi-2223/Ag/Ni tapes were studied. The phase compositions of the samples were characterized using XRD. The microstructure was observed using SEM. Experimental results indicate that higher temperature is more conducive to the formation of Bi-2223 phase at an atmosphere of 8.5% O 2 . After the two-step heat treatment, the critical current of samples is about 67.5 A.展开更多
The Bi-2223/Ag tapes were prepared with spray-died powders, which are of different particle sizes and phase assemblages by varying the annealing time in pure oxygen. Longer time annealing degraded the reactivity of pr...The Bi-2223/Ag tapes were prepared with spray-died powders, which are of different particle sizes and phase assemblages by varying the annealing time in pure oxygen. Longer time annealing degraded the reactivity of precursor powder, which in turn resulted in an incomplete conversion from precursors to Bi-2223, porosity core and misaligned grains in fully processed tapes. The best Jc in short pressed samples varied from 29.7 to 47kA/cm2 for the tapes made from different powders.展开更多
A hybrid energy transmission pipeline is proposed with the aim of long-distance cooperative transmission of electricity and chemical fuels, which is composed of an inner high-temperature superconducting (HTS) power ca...A hybrid energy transmission pipeline is proposed with the aim of long-distance cooperative transmission of electricity and chemical fuels, which is composed of an inner high-temperature superconducting (HTS) power cable and outer liquefied natural gas (LNG) pipeline. The flowing LNG could maintain the operating temperature of the inner HTS power cable within the range of 85 K-90 K, thus the Bi-2223 superconductors in the HTS power cable produce little Joule loss with the transmission current below the critical current. Owing to the advantages of high power density, low transmission losses and economical manufacturing costs, the hybrid energy transmission pipeline is expected to be widely utilized in the near future. In order to ensure the safety of the HTS power cable and explosive LNG in case of short-circuit faults, this paper tests and analyzes the characteristics of Bi-2223 HTS tapes of the Type HT-CA, Type HT-SS and Type H models under short-circuit current impacts at the LNG cooling temperature (85 K-90 K). An experimental platform is designed and established for the ampacity tests of HTS tapes above LN2 cooling temperature (77 K). The AC over-current impact tests at 85 K-90 K are carried out on each sample of Bi-2223 tapes respectively, and the experimental results are analyzed and compared to evaluate their performances under different operating conditions. The results indicate that the Type HT-CA tape can withstand 50 Hz short-circuit current impact with the amplitude of 1108 A (10 times of critical current Ic ) for 100 ms at 90 K, and its resistance is the smallest of the three tested samples under similar current impacts. Therefore, the Type HT-CA Bi-2223 tape is the optimal superconductor of the HTS power cable in the hybrid energy transmission pipeline.展开更多
Samples of Bi-2223/Ag tapes fabricated with powders contained different lead oxide compounds were annealed at a temperature lower than the formation temperature of Bi-2223 phase before traditional heat treatment, whic...Samples of Bi-2223/Ag tapes fabricated with powders contained different lead oxide compounds were annealed at a temperature lower than the formation temperature of Bi-2223 phase before traditional heat treatment, which was called pretreatment. In pre-treatment stage, samples were heat treated at 780 ℃ in 8.5% O2, and the dwelling time is different. Experimental results show that pre-treatment had different influence on the formation and size of the Bi-2223 grains for tapes fabricated with powders contained different lead oxide compounds. For tapes contained both Ca2PbO4 and the 3321 phase, the decomposition of the 3321 phase enhanced the growth of Bi-2212 grains during pre-treatment process, which promoted the formation of Bi-2223 phase and enhanced the superconducting properties of Bi-2223/Ag tapes.展开更多
This paper aims to briefly review the phenomenal role of superconductivity in wide ranging cable technological applications.HTS(high temperature superconducting)cable applications proved to expand a diverse range of e...This paper aims to briefly review the phenomenal role of superconductivity in wide ranging cable technological applications.HTS(high temperature superconducting)cable applications proved to expand a diverse range of economic and technical viability within electric transmission.HTS cable technology proved to attain low loss power transmission along with large electric power capacity that comes with great benefits:energy conservation,carbon dioxide reduction,resource preservation,and energy saving.Due to the following advantages,HTS cable power technology is widely promoted and readily constructed for implementation around the world.展开更多
A 630-kVA 10.5 kV/0.4 kV three-phase high temperature superconducting(HTS)power transformer was successfully developed and tested in a live grid.The windings were wound by hermetic stainless steelreinforced multi-fila...A 630-kVA 10.5 kV/0.4 kV three-phase high temperature superconducting(HTS)power transformer was successfully developed and tested in a live grid.The windings were wound by hermetic stainless steelreinforced multi-filamentary Bi2223/Ag tapes.The structures of primary windings are solenoid with insulation and cooling path among layers,and those of secondary windings consist of double-pancakes connected in parallel.Toroidal cryostat is made from electrical insulating glass fiber reinforced plastics(GFRP)materials with room temperature bore for commercial amorphous alloy core with five limbs.Windings are laid in the toroidal cryostat so that the amorphous core operates at room temperature.An insulation technology of double-half wrapping up the Bi2223/Ag tape with Kapton film is used by a winding machine developed by the authors.Fundamental characteristics of the transformer are obtained by standard short-circuit and no-load tests,and it is shown that the transformer meets operating requirements in a live grid.展开更多
基金Acknowledgement This research is supported by the National Natural Science Foundation of China （grant No. 50575114 and No. 50635050） and by Beijing Natural Science Foundation （grant No. 3052010） and by China Postdoctoral Science Foundation （ grant No. 20080430360）.
文摘Diffusion bonding of multifilamentary Ag/Bi-2223 （ Bi2 Sr2 Ca2 Cu3Ox ） superconducting tapes has been performed successfally. Three types of joints, namely, with sih,er interlayer （type Ⅰ）, bonded directly （type Ⅱ）, with Bi-2212 （BizSr2Ca1 Cu2Ox ） powder interlayer or with Bi-2223 powder interlayer （type Ⅲ） were researched, respectively. The critical currents（ Ic ） of these joints were measured ond microstructures of the joints were evaluated by scanning electron microscope （SEM）. The result shows that type Ⅰ is non-superconducting joint with very low resistance, and type Ⅱ joint and type Ⅲ （with Bi-2212 or Bi-2223 ） joints are both of superconducting property. By comparing, type Ⅱ joint possesses most exceUent superconductivity, type Ⅲ joint with Bi-2223 powder interlayer takes the second place, and type ,任家烈 joint with Bi-2212 powder interlayer is least.
文摘Bi-2223 precursor powders are prepared by both oxalate co-precipitation(CP) and spray pyrolysis(SP) methods.The influence of fabrication methods on the superconducting properties of Bi-2223 tapes are systematically studied. Compared to the CP method, SP powder exhibits spherical particle before calcination and smaller particle size after calcinations with more uniform chemical composition, which leads to a lower reaction temperature during calcination process for Bi-2223 tapes. Meanwhile, the non-superconducting phases in SP powder are more uniformly distributed with smaller particle sizes. These features result in finer homogeneity of critical current in large-length of Bi-2223 tape, higher density of filaments and better texture after heat treatment. Therefore,the SP method could be considered as a better route to prepare precursor powder for large-length Bi-2223 tape fabrication.
基金financially supported by the National High Technology Research and Development Program(863program)(No.2009AA03Z202)the Fundamental Research Funds for the Central Universities(No.N100423006and No.N110823001)
文摘To reduce the production cost of Bi-2223 superconducting tapes, Bi-2223/Ag/Ni tapes were fabricated by the powder-in-tube process. The effect of heat treatment on the microstructure and critical current of the Bi-2223/Ag/Ni tapes were studied. The phase compositions of the samples were characterized using XRD. The microstructure was observed using SEM. Experimental results indicate that higher temperature is more conducive to the formation of Bi-2223 phase at an atmosphere of 8.5% O 2 . After the two-step heat treatment, the critical current of samples is about 67.5 A.
文摘The Bi-2223/Ag tapes were prepared with spray-died powders, which are of different particle sizes and phase assemblages by varying the annealing time in pure oxygen. Longer time annealing degraded the reactivity of precursor powder, which in turn resulted in an incomplete conversion from precursors to Bi-2223, porosity core and misaligned grains in fully processed tapes. The best Jc in short pressed samples varied from 29.7 to 47kA/cm2 for the tapes made from different powders.
基金supported by National Key R&D Project under Grant(2018YFB0904400).
文摘A hybrid energy transmission pipeline is proposed with the aim of long-distance cooperative transmission of electricity and chemical fuels, which is composed of an inner high-temperature superconducting (HTS) power cable and outer liquefied natural gas (LNG) pipeline. The flowing LNG could maintain the operating temperature of the inner HTS power cable within the range of 85 K-90 K, thus the Bi-2223 superconductors in the HTS power cable produce little Joule loss with the transmission current below the critical current. Owing to the advantages of high power density, low transmission losses and economical manufacturing costs, the hybrid energy transmission pipeline is expected to be widely utilized in the near future. In order to ensure the safety of the HTS power cable and explosive LNG in case of short-circuit faults, this paper tests and analyzes the characteristics of Bi-2223 HTS tapes of the Type HT-CA, Type HT-SS and Type H models under short-circuit current impacts at the LNG cooling temperature (85 K-90 K). An experimental platform is designed and established for the ampacity tests of HTS tapes above LN2 cooling temperature (77 K). The AC over-current impact tests at 85 K-90 K are carried out on each sample of Bi-2223 tapes respectively, and the experimental results are analyzed and compared to evaluate their performances under different operating conditions. The results indicate that the Type HT-CA tape can withstand 50 Hz short-circuit current impact with the amplitude of 1108 A (10 times of critical current Ic ) for 100 ms at 90 K, and its resistance is the smallest of the three tested samples under similar current impacts. Therefore, the Type HT-CA Bi-2223 tape is the optimal superconductor of the HTS power cable in the hybrid energy transmission pipeline.
基金National High Technology Research and Development ("863") Program (2009AA03Z202)
文摘Samples of Bi-2223/Ag tapes fabricated with powders contained different lead oxide compounds were annealed at a temperature lower than the formation temperature of Bi-2223 phase before traditional heat treatment, which was called pretreatment. In pre-treatment stage, samples were heat treated at 780 ℃ in 8.5% O2, and the dwelling time is different. Experimental results show that pre-treatment had different influence on the formation and size of the Bi-2223 grains for tapes fabricated with powders contained different lead oxide compounds. For tapes contained both Ca2PbO4 and the 3321 phase, the decomposition of the 3321 phase enhanced the growth of Bi-2212 grains during pre-treatment process, which promoted the formation of Bi-2223 phase and enhanced the superconducting properties of Bi-2223/Ag tapes.
文摘This paper aims to briefly review the phenomenal role of superconductivity in wide ranging cable technological applications.HTS(high temperature superconducting)cable applications proved to expand a diverse range of economic and technical viability within electric transmission.HTS cable technology proved to attain low loss power transmission along with large electric power capacity that comes with great benefits:energy conservation,carbon dioxide reduction,resource preservation,and energy saving.Due to the following advantages,HTS cable power technology is widely promoted and readily constructed for implementation around the world.
基金supported by the Ministry of Science and Technology of China (2002AA306381)Tebian Electric Apparatus Stock Co.,Ltd (TBEA)and the‘100 Talents Project’of Chinese Academy of Sciences,China (0640111C11).
文摘A 630-kVA 10.5 kV/0.4 kV three-phase high temperature superconducting(HTS)power transformer was successfully developed and tested in a live grid.The windings were wound by hermetic stainless steelreinforced multi-filamentary Bi2223/Ag tapes.The structures of primary windings are solenoid with insulation and cooling path among layers,and those of secondary windings consist of double-pancakes connected in parallel.Toroidal cryostat is made from electrical insulating glass fiber reinforced plastics(GFRP)materials with room temperature bore for commercial amorphous alloy core with five limbs.Windings are laid in the toroidal cryostat so that the amorphous core operates at room temperature.An insulation technology of double-half wrapping up the Bi2223/Ag tape with Kapton film is used by a winding machine developed by the authors.Fundamental characteristics of the transformer are obtained by standard short-circuit and no-load tests,and it is shown that the transformer meets operating requirements in a live grid.
