# 이중철심을 이용한 병렬연결된 자기결합형 초전도한류기의 전류제한 및 회복특성

• Accepted : 2016.05.12
• Published : 2016.05.31
• 45 9

#### Abstract

In this paper, in order to support the peak current limiting function depending on the intensity of the fault current at the early stage of failure, a two magnetically coupled type superconducting fault current limiter (SFCL) is proposed, which includes high-Tc superconducting (HTSC) element 1, where the existing primary and secondary coils are connected to one iron core in parallel, and HTSC element 2, which is connected to the tertiary winding using an additional iron core. The results of the experiments in this study confirmed that the two magnetic coupling type SFCL having coil 1 and coil 2 connected in parallel using dual iron cores is capable of having only HTSC element 1 support the burden of the peak current when a failure occurs. The reason for this is that although HTSC element 1 was quenched and malfunctioned because the instantaneous factor of the initial fault current was large, the current flowing to coil 3 did not exceed the critical current, which would otherwise cause HTSC element 2 to be quenched and not function. In order to limit the peak current upon fault through the sequential HTSC elements, the design should allow it to have the same value as the low value of coil 1 while having coil 3 possess a higher self-inductance value than coil 2. In addition, a short-circuit simulation experiment was conducted to examine and validate the current limiting and recovery characteristics of the SFCL when the winding ratio between coil 1 and coil 2 was 0.25. Through the analysis of the short-circuit tests, the current limiting and recovery characteristics in the case of the additive polarity winding was confirmed to be superior to that of the subtractive polarity winding.

#### Keywords

Two Magnetically Coupled Type;Superconducting Fault Current Limiter (SFCL);Fault Current Limiting;Recovery Characteristics;High-Tc Superconducting (HTSC) Element

#### References

1. H. Shimizu, Y. Yokomizu, T. Matsumura, and N. Murayama, "Proposal of Fux Flow Resistance Type Fault Current Limiter using Bi2223 High $T_c$ Superconducting bulk", IEEE Trans. Appl. Supercond., Vol.12, No.1, pp. 876-879, 2002. https://doi.org/10.1109/TASC.2002.1018540
2. A. Hekmati, "Proposed Design for a Tunable Inductive Shield-Type SFCL", IEEE Trans. Appl. Supercond., Vol.24, No.4, Article #.5601907, 2014.
3. B. Li, F. Guo, J. Wang, C. Li, "Electromagnetic Transient Analysis of the Saturated Iron-Core Superconductor Fault Current Limiter", IEEE Trans. Appl. Supercond., Vol.25, No.3, Article #.5600805, 2015.
4. Y. Jiang, S. Dongyuan, D. Xianzhong, T. Yuejin, C. Shijie, "Comparison of Superconducting Fault Current Limiter in Power System", IEEE Power Engineering Society Summer Meeting, Vol.1, pp. 43-47, 2001.
5. H.-S. Choi, O.-B. Hyun, H.-R. Kim, K.-B. Park, "Switching Properties of a Hybrid Type Superconducting Fault Current Limiter Using YBCO Stripes", IEEE Trans. Appl. Supercond., Vol.14, No.3, pp. 1833-1838, Sept. 2002.
6. S.-C. Ko, T.-H. Han, S.-H. Lim, "Current- Limiting and Recovery Characteristics of a Flux-Lock-Type SFCL with Two Adjustable Operational Currents", J. Korean Phys. Soc., Vol.65, No.2, pp. 253-256, July, 2014. https://doi.org/10.3938/jkps.65.253
7. S. Ko, T.-H. Han, S.-H. Lim, "Analysis on Fault Current Limiting and Recovery Characteristics of a Flux-Lock Type SFCL with an Isolated Transformer", Physica C, Vol.484, pp. 263-266, January, 2013. https://doi.org/10.1016/j.physc.2012.03.041
8. S.-C. Ko, T.-H. Han, S.-H. Lim, "Analysis on Current Limiting Characteristics According to the Influence of the Magnetic Flux for SFCL with Two Magnetic Paths", J. Electr. Eng. Technol., Vol.9, No.6, pp. 1909-1913, Dec. 2014. https://doi.org/10.5370/JEET.2014.9.6.1909
9. T.-H. Han, S.-C. Ko, S.-H. Lim, "Study on Current Limiting Characteristics of a Flux-Lock Type SFCL using Series Connected Two Coils with Twice Triggering Operation", J. Electr. Eng. Technol., Vol.9, No.3, pp. 777-781, June, 2014. https://doi.org/10.5370/JEET.2014.9.3.777
10. S.-H. Lim, Y.-P. Kim, S.-C. Ko, "Effect of Peak Current Limiting in Series-Connection SFCL with Two Magnetically Coupled Circuits Using E-I Core", IEEE Trans. Appl Supercond., Vol.26, No.3, Article#.5600404, April, 2016.
11. S.-C. Ko and S.-W. Lee, "Analysis on Current Limiting Characteristics of Series Connection- Type SFCL with Two Magnetically Coupled Circuits Applied into a Simulated Power System", J. KIEEME., Vol.26, No.1, pp. 68-721, January, 2013.

#### Acknowledgement

Supported by : 한국연구재단