• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2000.02a
• /
• pp.147-149
• /
• 2000

Samsung Superconducting Test Facility (SSTF) will be built at SAIT, Taejeon. The superconducting cables to be used for KSTAR magnets are going to be tested in SSTF. The background magnet in SSTF is needed to simulate harsh magnetic environment for testing short CICC samples as well as full-scale magnets. The main coils can make central magnetic field of up to 8 Tesla and the blip coils can maintain fast ramping rate of 20T/s. The cancellation coils reduce the disturbance of main coils due to blip coils. The magnetic field distribution of these coils has been obtained with finite element method as well as the direct integration method.

• Progress in Superconductivity and Cryogenics
• /
• v.2 no.2
• /
• pp.44-48
• /
• 2000

The high temperature superconducting bulk can be used as the rotor of an ac motor. This paper presents the fabrication and test results of a ac motor with HTS bulk rotor. The rotor of a conventional squirrel cage induction motor was replaced with cylinder type YBCO bulk. Height and outer diameter of the HTS bulk was 15mm and 46mm, respectively. Eddy current brake using aluminium disk was used to measure the torque of the HTS motor. No load test, locked rotor test and load test were performed to examine the characteristics of the HTS motor. Test results show the motor can rotate at synchronous speed without any special starting circuit. Maximum output power of the constructed HTS motor was 408W.

• Proceedings of the KAIS Fall Conference
• /
• 2008.11a
• /
• pp.93-96
• /
• 2008

500나노 입자 및 기본 물성이 우수한 이중층상구조금속수화물(LDH)를 합성하고 PVC 수지에 적용하여 고온, 저온열안정성 및 가공특성으로 인장강도, 신율, 체적저항 등이 우수한 시제품을 합성한 후 개발한 이중층상구조금속수화물(LDH) 시제품을 사용하여 무독성안정제(금속석검계), 내외부활제류, 가공조제, 산화방지제 등 기타 첨가제 등을 사용하여 PVC수지에 적용하여 수지배합에 따른 시험편을 제작하여 배합비별로 고온, 및 저온열안정성, 체적고유저항, 가공성(인장강도, 신율 등), 내후성, 초기 착색성 등 물성, 기계적 가공특성 및 성능이 우수한 할로겐수지용 무독성배합을 개발한다. 최종적으로 개발한 이중층상구조금속수화물(LDH)을 사용하여 제조하여 PVC 수지의 열안정성 및 기계적 가공특성이 우수한 중금속계대체용 무독성복합열안정제를 개발하였다.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2003.02a
• /
• pp.156-159
• /
• 2003

A free piston and free displacer(FPFD) Stirling cryocooler for cooling infrared and cryo-sensors is currently under development at KIMM(Korea Institute of Machinery ＆ Materials). Our coolers are specifically designed to work in the thermal imaging device and to meet requirements such as cooling capacity, COP and high reliability. In this work, Stirling cryocooler is designed, manufactured and fabricated, and performance characteristics are investigated. This cooler delivers approximately 0.5W cooling at 77K for 30W ∼ 40W of input power from AC power supply. And, after the climate performance and reliability for the cryocooler is discussed, operating test without cooling load at the cold end is performed.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2003.10a
• /
• pp.263-268
• /
• 2003

The Electrical insulation design and testing of high temperature superconducting (HTS) coil for high temperature superconducting fault current limiter (HTSFCL) has been performed. Electrical insulating factors of HTS coil for HTSFCL are turn-to-turn, layer-to-layer. The electrical insulation of turn-to-turn depends on surface length, and the electrical insulation of layer-to-layer depends on surface length and breakdown strength of L$N_2$. Therefore, two basic characteristics of breakdown and flashover voltage were experimentally investigated to design electrical insulation for 6.6㎸ Class HTSFCL. We used Weibull distribution to set electric field strength for insulation design. And mini-model HTS coil for HTSFCL was designed by using Weibull distribution and was manufactured to investigate breakdown characteristics. The mini-model HTS coil had passed in AC and Impulse withstand test.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2003.10a
• /
• pp.163-166
• /
• 2003

This paper presents the results of a series of performance tests for the Stilting cryocooler. Infrared sensor systems incorporating cryocoolers are required to be qualified to the appropriate environmental specification. Linear drive Stilting cryocooler have matured to the stage of undergoing formal qualification test program The thermal environmental test of the Stilting cryocooler is presented in this paper. We performed that low and high temperature keeping test from －4$0^{\circ}C$ to ＋6$0^{\circ}C$ and operating test at high and low temperature cyclic range with acceptance tests performed at scheduled intervals. Cooling capacity was determined as a function of cooler components temperatures at the compressor, hot end and cold tip. Tests performed on this cooler have been successful with a measured cooling performance of more than 0.8W＠80K for 23$^{\circ}C$ ambient temperature with 40 $W_{ac}$ input power.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2003.10a
• /
• pp.10-13
• /
• 2003

6.6㎸rms/200Arms DC reactor type superconducting fault current limiter (SFCL) has been developed. This paper deals with the manufacture and short-circuit test of the SFCL. DC reactor was the HTS solenoid coil whose inductance was 84mH. AC/DC power converter was performed as the dual-mode operation. The short-term run(1 sec) and short-circuit test of this SFCL was performed successfully. The experimental results have a similar tendency to the simulation results. In short-circuit test, at 2 cycles after the fault, fault current limitation rate was about 30％.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2003.10a
• /
• pp.324-327
• /
• 2003

The needs for the cryocooler which has high reliability and long MTTF are increased in the military and commercial thermal imaging system The gas contamination wear, leakage of the working fluid, fatigue and etc. have the significant effects on the reliability and MTTF(Mean Time To Failure) or MTBF(Mean Time Between Failure) of the Stirling cryocooler. In the KIMM, the Stilting cryocooler with the linear compressor was released after the several performance tests were performed. This paper describe the experimental facility for the MTTF evaluation and some typical results of the Stilling cryocooler.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2003.10a
• /
• pp.281-283
• /
• 2003

High temperature superconducting power cable requires forced flow cooling. Liquid nitrogen is circulated by a pump and cooled back by cooling system. Typical operating temperature range is expected to be between 65K and 80K. Subcooler heat exchanger uses saturated liquid nitrogen boiling on the shell side to subcool the circulating liquid nitrogen stream that cools the HTS cable. The paper describes performance tests of the cooling system. The test items are heat exchanging performance of subcooler. pressure drop between supply and return lines, heat transfer coefficient inside former, cable cryostat heat leak and simulation of electrical load of HTS cable.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2003.10a
• /
• pp.320-323
• /
• 2003

This paper presents the results of a series of performance tests for the Stilting cryocooler. A free piston and free displacer(FPFD) Stilting cryocooler for cooling infrared and cryo-sensors is currently under development at KIMM. Our coolers are specifically designed to work in the thermal imaging device and to meet requirements such as cooling capacity, COP and high reliability. In this work, Stilting cryocooler is designed, manufactured and fabricated, and performance characteristics for the cooling capacity / applied input power and cool down time are investigated. This cooler delivers approximately 0.9W cooling at 80K for 30W ~ 40W of input power. And, It takes approximately 2 minutes to cool down to 80K at the ambient temperature of 23$^{\circ}C$.