• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.67-68
• /
• 2011

This paper analysed a protective equipment in power distribution system linked distribution power system when a superconducting fault current limiter(SFCL) is installed. This paper focused on a recloser, because the recloser is a general protective equipment. When power distribution system linked distribution power system, a fault current is increased by adding fault current of distribution power system. The increased fault current makes many problems. But SFCLs are limiting fault current and help the protective equipment to operate normal process. We analysed the operation of protective equipment in power distribution system linked distribution power system with SFCLs.

• Progress in Superconductivity and Cryogenics
• /
• v.4 no.1
• /
• pp.110-113
• /
• 2002

The high-tc superconducting fault current limiters (SFCL) are studied worldwide to be classified as resistive type or inductive type such as magnetic shielding type and dc reactor type. This Paper deals with an open core type SFCL, a kind of magnetic shielding type SFCL. We manufactured a 30 kVA open core type SFCL. It was modified from the old one with a rated power of 8 kVA. We stacked four superconducting tubes as magnetic shielding material and used the same primary winding as the old one. The experiments were performed with a maximum source voltage of 1 kV. The results show that the fault current in the source voltage of 1 kVrms was reduced to be about 105 Apeak, which was calculated to be about 22 % of the fault current in the system without an SFCL.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.53 no.12
• /
• pp.661-669
• /
• 2004

As the load density of KEPCO system is higher, the fault current can be much higher than SCC(Short Circuit Capacity) of circuit breaker. Fault current exceeding the rating of circuit breaker is a very serious problem in high density load area, which can threaten the stability of whole power system. Even though there are several alternatives to reduce fault current, as the superconductivity technology has been developed, the HTS-FCL (High Temperature Superconductivity Fault Current Limiter) can be one of the attractive alternatives to solve the fault current problem. This study presents the application plication of 154kV HTS-FCL in Korean power system.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2000.02a
• /
• pp.133-135
• /
• 2000

We fabricated resistive super- conducting fault current limiters (SFCL) based on YBCO thin films grown on a 2" diameter $Al_{2}$O_{3} substrate. The minimum quench current of the current minimum quench current of the current limiting element was about 8 $A_{peak}. This SFCL successfully controlled the fault current below 14.3 $A_{peak} at the voltage of 100$V_{rms}, which is otherwise to increase up to 141$A_{peak}. and the quench completion time is less than 3 msec. The temperature of the current limiting element rose to about 200K in 3 cycles after fault. The SFCL showed reproducible characteristics during hundreds times of repeated experiments.ents.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.57 no.7
• /
• pp.1135-1140
• /
• 2008

Superconducting fault current limiters (SFCL) have been progressing due to the development of superconducting technology. The resistor type SFCL is one of the promising current limiting devices in power system for its effective operation. For proper application and operation of a SFCL, the prior investigation of fundamental characteristics and its effects to the distribution systems are needed. The most important current limiting behavior of a SFCL is dominated by quenching and recovery characteristics. In this paper, the resistive type SFCL was developed by using EMTP/ATPDraw and MODELS language. The operating characteristics and current limiting behaviors of the SFCL in distribution systems have been simulated and investigated.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.257-258
• /
• 2008

The inrush current of a transformer is a high-magnitude and harmonic-rich current generated when the transformer core is driven into saturation during energizing. The inrush current usually leads to undesirable effects, for example potential damage to the transformer, misoperation of a protective relay, and power quality deterioration in the distribution power system. Inrush current reduction is therefore important for power system operation. In this paper, to reduce the inrush current, the insertion resistance of the Superconducting Fault Current Limiter (SFCL) that is connected in series with the transformer in the distribution system is used. This paper implements the SFCL by using the Electromagnetic Transient Program-Restructured Version (EMTP-RV) to model the SFCL in the distribution system. The simulation results show the beneficial effects of the SFCL for reduction of the inrush current.

• 한국초전도학회:학술대회논문집
• /
• v.16
• /
• pp.84-84
• /
• 2006

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2001.02a
• /
• pp.176-177
• /
• 2001

Three nearly identical superconducting fault current limiters (SFCLs) were connected in series to increase the voltage ratings. A slight difference in the quench starting point of individual SFCL units produced significantly imbalanced power distribution when connected in series. The imbalance was successfully removed by connecting a shunt resistor to one SFCL in parallel. 1.2 kV SFCL was designed with five current limiting elements and two or three shunt resistors.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.65 no.5
• /
• pp.873-877
• /
• 2016

This paper proposed the structure that applied superconductors to the neutral line of a transformer and applied the normal conductors to the third line. The superconductor applied to the neutral line of a transformer limited the peak value of initial fault current, while the normal conductor finally limited the fault current. In order to secure the operating reliability of transformer type Superconducting Fault Current Limiter (SFCL) of previously proposed structure, we analyzed the operating characteristics according to the fault types. We tested a line-to-ground fault and a line-to-line fault. As a result of the experiment, all the faults showed that the superconductor stably limited the peak-value of initial fault current. Also, the normal conductor finally limited the fault current. Based on this research results, We thought that if the structure of inserting superconductor into the neutral line is applied to the real system, it could improve the reliability and stability of the power system.

• Progress in Superconductivity and Cryogenics
• /
• v.16 no.2
• /
• pp.59-63
• /
• 2014

HTS power cable bypass the fault current through the former to protect superconducting tapes. On the other hand, the fault current limiting (FCL) power cable can be considered to mitigate the fault current using its increased inductance and resistance. Using the increased resistance of the cable is similar to the conventional resistive fault current limiter. In case of HTS power cable, the magnetic field of HTS power cable is mostly shielded by the induced current on the shield layer during normal operation. However, quench occurs at the shield layer and its current is kept below its critical current at the fault condition. Consequently, the magnetic field starts to spread out and it generates additional inductive impedance of the cable. The inductive impedance can be enhanced more by installing materials of high magnetic susceptibility around the HTS power cable. It is a concept of SFCL power cable. In this paper, a sample SFCL power cable is suggested and experimental results are presented to investigate the effect of iron cover on the impedance generation. The tests results are analyzed to verify the generation of the inductive and resistive impedance. The analysis results suggest the possible applications of the SFCL power cable to reduce the fault current in a real grid.