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The Multi Temperature superconducting (HTS) electric equipment is developed with the help of bi-223 wire successfully commercialized 1st generation HTS wire. Current sharing in two types of 5-stacked HTS solenoid coils, made up of 1 copper layer which is a current buffer layer of HTS coil and 4 HTS wire layers is analyzed.

The 4-probe method with voltage tap on terminals is used for the measurement of the critical current of multistrand high-T(sub c) superconducting (HTS) cables. The conclusion states that the real critical current of multi-strand is smaller than sum of each critical current of each path.

A study is conducted to examine the determination of heater triggering parameters of high-T(sub c) superconducting (HTS) power supply with series-connected double-pancake load. Based upon the analysis, the 8 A electromagnet current and the 1.5 A dc heater current are derived and 8 s and 20 s for the pumping period are selected.

A study is conducted to examine the properties of some insulating materials, which are used in high temperature superconducting (HTS) wires. The multi-layer insulating method for current lead is suggested which is stable at cryogenic temperature.

Discussing the electrical degradation of two types of specimens using Bi-2223 wires is investigated by continuous DC current transport is presented. It is concluded that the variation of I(sub c) and degradation rate in the same specimen shows that the Bi-2223 wire has several weak regions.

Characteristics of a heater-triggered switching system for charging a Bi-2223 double-pancake load are investigated and reported.

The optimal approach for winding HTS magnets is investigated and discussed.

Research involving a modified bridge type superconducting fault current limiter with reverse magnetized core is described and discussed.

Development of a superconducting DC reactor for 1.2 kV/80 A inductive fault current limiter is described and discussed.

A short-circuit test of a three-phase DC reactor-type fault current limiter (FCL) is described and discussed.

To develop a High-Tc superconducting (HTS) magnet that is applicable to the high voltage electric device applications, it is necessary to consider several important factors such as large critical current, reliable electric insulation system, stable cryogenic status, expected economic benefits, and so on. This paper deals with the skills to design and manufacture the high voltage HTS DC magnet accepting large pulse input current. The multi-stacked HTS solenoid winding was suggested for the HTS magnet having large critical current. To protect the HTS winding, when quenched, the copper layer was suggested as a buffer sharing the large pulse current. The thin grooves on the GFRP bobbins not only guide the HTS winding but also play the role of electrical insulation for the high voltage application. With regard to the thermal stability of the magnet, sub-cooled liquid nitrogen cooling system was used for the cooling system of the HTS DC magnet. To reduce the resistance of the normal conducting parts in the HTS magnet, several HTS tapes were additionally attached on these parts. Based on this study, the HTS DC magnet for the 2.3 MVA class high-Tc superconducting fault current limiter (HTSFCL) was successfully manufactured and tested. The HTS DC magnet developed by this study endured 2.53 MJ (18.66 MWmax) without any evidence of quench. [ABSTRACT FROM AUTHOR]

The 4-probe method with a voltage tap on terminals has been used for the measurement of the critical current of multi-strand high-Tc superconducting (HTS) cables. The critical current of cables is obtained as the measured total current divided by the number of conductors when the terminal voltage exceeds the predetermined criterion of critical current. However, because of the nonuniform current share due to the different critical currents, shapes, and other characteristics of each conductor, this method is not applicable to the multi-strand HTS cable. To determine the critical current of multi-strand HTS cable, the critical current of each conductor must be measured with different method. In this paper, the current share and the critical current of each conductor in multi-strand cable were measured with specially made pick-up coils and voltage taps. It is presented that the real critical current of multi-strand is smaller than sum of each critical current of each path. Different resistances appeared in each HTS wire are the main cause of nonuniform current share. [ABSTRACT FROM AUTHOR]