• 대한전기학회논문지:전력기술부문A
• /
• 제53권11호
• /
• pp.619-623
• /
• 2004

We proposed the bridge type superconducting fault current limiter(SFCL) using switching operation of high-Tc superconducting(HTSC) thin film. The proposed bridge type SFCL consists of HTSC thin film, a diode bridge and a dc reactor. The controller for the operation of an interrupter is required in the conventional bridge type SFCL to prevent the continuous increase of fault current after a fault happens. On the other hand, the proposed bridge type SFCL can limit the fault current without the interrupter and the controller for its operation by the resistance generated when the gradually increased fault current exceeds HTSC thin film's critical current. We calculated the time when the gradually increased fault current started to be limited by the resistance generated in HTSC thin film after a fault happened and confirmed that it could be dependent on the amplitude of source voltage. The experimental results well agreed with the calculated ones from simulation.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.83-85
• /
• 2004

We proposed the bridge type fault current limiter(FCL) using switching operation of high-Tc superconducting(HTSC) thin film. The proposed bridge type FCL consists of HTSC thin film, a diode bridge and a dc reactor. The controller for the operation of an interrupter is required in the conventional bridge type FCL to prevent the continuous increase of fault current after a fault happens. On the other hand, the proposed bridge type FCL can limit the fault current without the interrupter and the controller for its operation by the resistance generated when the gradually increased fault current exceeds HTSC thin film's critical current. We calculated the time when the gradually increased fault current started to be limited by the resistance generated in HTSC thin film after a fault happened and confirmed that it could be dependent on the amplitude of source voltage. The experimental results well agreed with the calculated ones from simulation.

• 한국전기전자재료학회논문지
• /
• 제19권3호
• /
• pp.273-279
• /
• 2006

High-$T_c$ superconducting (HTSC) power cable is one of the interesting parts in power application using HTSC wire. However, its stacked structure makes the current distribution between conducting layers non-uniform due to difference between self inductances of conducting layers and mutual inductances between two conducting layers, which results in lower current transmission capacity of HTSC power cable. In this paper, the transport current distribution between conducting layers was investigated through the numerical analysis for the equivalent circuit of HTSC power cable with a shield layer, and compared with the case of without a shield layer. The transport current distribution due to the increase of the contact resistance in each layer was improved. However, its magnetization loss increased as the contact resistance increased. It was confirmed from the analysis that the shield layer was contributed to the improvement of the current distribution between conducting layers if the winding direction and the pitch length were properly chosen.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 기술교육전문연구회
• /
• pp.20-23
• /
• 2003

The operational characteristics of flux-lock type high-Tc superconducting fault currentlimiters(HTSC-FCLs) was described and currents equation at each coil was derived from equivalent circuit. $YBa_{2}Cu_{3}O_{7-x}$(YBCO) thin film was used as the current limiting elements of the flux-lock type HTSC-FCL, which were fabricated by etching the YBCO thin film into 2 mm wide and 420 mm long meander line consisting of foureen stripes with different length. The 2nd peak on the current of coil 2 after a fault disappeared by current of the 3rd winding, which was installed in the flux-lock type HTSC-FCL.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
• /
• pp.535-538
• /
• 2004

Superconducting transmission power cable is one of interesting parts in power application using high temperature superconducting wire. One of important parameters in high-temperature superconduting (HTSC) cable design is transport current distribution because it is related with current transmission capacity and AC loss. In this paper, the transport current distribution at conducting layers was investigated through the analysis of the equivalent circuit for HTSC power cable with shield layer and compared with the case of without shield layer. The transport current distribution due to the pitch lenght was improved in the case of HTSC power cable with shield layer from the analysis.

• Transactions on Electrical and Electronic Materials
• /
• 제6권4호
• /
• pp.186-189
• /
• 2005

We have fabricated superconducting HTSC ceramic thick films by chemical process. c-axis oriented HTSC thick films have been attempted bi-axially textured Ni tapes. The x-ray diffraction pattern of the HTSC thick films contained superconducting phase crystal. The critical temperature and critical current density was 110K.

• International Journal of Railway
• /
• 제5권3호
• /
• pp.114-116
• /
• 2012

The technology of high-temperature superconductive (HTSC) maglev trains has become mature and ready for a commercial use ten years after its first prototype was made by Jiasu Wang and Suyu Wang. However, an appropriate roadmap in applying it to the market is crucial for its success because superconductivity mystery remains veiled and public safety concern may prevent it from being used.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.12-14
• /
• 2004

Superconducting transmission power cable is one of interesting parts in power application using high temperature superconducting wire. One of import ant parameters in high-temperature superconduting (HTSC) cable design is transport current distribution because it is related with current transmission capacity and AC loss. In this paper, the transport current distribution at conducting layers was investigated through the analysis of the equivalent circuit for HTSC power cable with shield layer and compared with the case of without shield layer. The transport current distribution due to of the contact resistance and the pitch was improved in the case of HTSC power cable with shield layer from the analysis.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
• /
• pp.681-682
• /
• 2006

This paper deals with the preliminary study on the HTSC levitation magnet for MAGLEV operating in persistent current mode (PCM). The high temperature superconducting (HTSC) levitation magnet consists of two single-pancake type coils wound with Bi-2223 wire and a persistent current switch (PCS). The levitation magnet was designed by using 3-D finite element analysis. The suspension system for high-speed electrodynamic suspension (EDS) maglev should operated in persistent current mode. It is important to develop a technology to minimize the joint resistance of splice between two HTSC wires. The PCS was observed with respect to various magnitude of charging current. Based on these results, the levitation system using HTSC wire will be further studied.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 하계학술대회 논문집 B
• /
• pp.1133-1135
• /
• 2004

Superconducting transmission power cable is one of interesting parts in power application using high temperature superconducting wire. One of important parameters in high-temperature superconducting (HTSC) cable design is transport current distribution because it is related with current transmission capacity and ac loss. In this paper, the transport current and magnetic field distributions at conducting layers were investigated through the analysis of the equivalent circuit for HTSC power cable with shield layer. The transport current distribution due to the pitch length and winding direction was improved in case of HTSC power cable with shield layer.