Improvement in operational characteristics of KEPCO’s line-commutation-type superconducting hybrid fault current limiter

• Published in: Physica. C, Superconductivity Vol. 484; pp. 267 - 271
• Main Authors: Yim, S.-W., Park, B.-C., Jeong, Y.-T., Kim, Y.-J., Yang, S.-E., Kim, W.-S., Kim, H.-R., Du, H.-I.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 15.01.2013; Elsevier
• Subjects: Applied sciences; Connection and protection apparatus; Constraining; Current limiters; Electric power generation; Electrical engineering. Electrical power engineering; Exact sciences and technology; Faults; First peak limitation; Hybrid FCL; Line commutation type; Modules; Protective; Superconducting module; Superconductivity; Transformers; Hybrid FCL; First peak limitation; Superconducting module; Line commutation type; Superconductive switch; Magnetic field effect; Electric transformer; Field distribution; Electromagnetic force; Power supply; AC losses; Fault current limiters
• ISSN: 0921-4534; 1873-2143
• DOI: 10.1016/j.physc.2012.03.056

► A line-commutation type hybrid FCL was modified for 1st peak current limitation. ► A superconducting module of current limitation and fault detection was fabricated. ► The superconducting module was applied to a hybrid FCL system and tested. ► 7.4kAp fault current was limited to 4.3kAp at the first-half cycle by the FCL. A 22.9kV class hybrid fault current limiter (FCL) developed by Korea Electric Power Corporation and LS Industrial Systems in 2006 operates using the line commutation mechanism and begins to limit the fault current after the first half-cycle. The first peak of the fault current is available for protective coordination in the power system. However, it also produces a large electromagnetic force and imposes a huge stress on power facilities such as the main transformer and gas-insulated switchgear. In this study, we improved the operational characteristics of the hybrid FCL in order to reduce the first peak of the fault current. While maintaining the structure of the hybrid FCL system, we developed a superconducting module that detects and limits the fault current during the first half-cycle. To maintain the protective coordination capacity, the hybrid FCL was designed to reduce the first peak value of the fault current by up to approximately 30%. The superconducting module was also designed to produce a minimum AC loss, generating a small, uniform magnetic field distribution during normal operation. Performance tests confirmed that when applied to the hybrid FCL, the superconducting module showed successful current limiting operation without any damage.