http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Kim, Myoung-Hoo,Kim, Jin-Seok,You, Il-Kyoung,Lim, Sung-Hun,Kim, Jae-Chul The Korean Institute of Electrical Engineers 2011 The Journal of International Council on Electrical Vol.1 No.1
This paper analyzed the selection of practical impedance of Superconducting fault current limiter (SFCL) on bus tie in a power distribution system. Generally, the parallel operation of main transformer offers a number of advantages. However, when a fault occurred in the parallel operation of main transformer, the fault currents could exceed the capacity of conventional protective device and might generate protective coordination problems. To solve these problems, the SFCL has been studied as the attractive device. Especially, in power distribution system on bus tie with SFCL, the effect of the resistance of SFCL could decrease the increased fault currents and could meet the capacity of conventional protective devices by them. Also, they could solve the protective coordination problems. Therefore, we analyzed the practical impedance of SFCL on bus tie in a power distribution system using PSCAD/EMTDC.
Improvement of Recloser-Fuse Operations and Coordination in a Power Distribution System With SFCL
Myoung-Hoo Kim,Sung-Hun Lim,Jae-Chul Kim IEEE 2011 IEEE transactions on applied superconductivity Vol.21 No.3
<P>In this paper, we describes how to coordinate between recloser and fuse in power distribution system with superconducting fault current limiters (SFCL). The recloser and fuses are the main overcurrent protective devices in power distribution system. Universally, to protect against permanent faults, fuses are installed on overhead feeder laterals and the reclosers as a backup protection against temporary faults remove many unnecessary outages. Here, the recloser is set to trip using TCC curve for a temporary fault before any of the fuses can melt. If the fault is a permanent fault, the fuse has to melt just before the last delay trip of the recloser. However, the application of a resistive SFCL in power distribution system affects the recloser-fuse operation and coordination as decreased fault currents. In case that when a permanent fault occurs, the recloser could be locked-out after the last delay trip before the fuses operate. Therefore, to solve these cases, we performed experiments which are the recloser-fuse operation and coordination in the modeled power distribution system with the SFCL. Based on the experimental verification, we improved to coordinate the recloser-fuse in power distribution system with SFCL.</P>
배전계통에 분산형 전원 증가에 따른 초전도 전류제한기 적용시 보호기기 협조동작 특성 분석
김명후(Myoung-Hoo Kim),김진석(Jin-Seok Kim),유일경(Il-Kyoung You),문종필(Jong-Fil Moon),임성훈(Sung-Hun Lim),김재철(Jae-Chul Kim) 대한전기학회 2009 대한전기학회 학술대회 논문집 Vol.2009 No.11
This paper analyzed that characteristic of coordinating operation of protective device in a power distribution system with Superconducting Fault Current Limiter (SFCL) and Distributed Generation (DG). In a power distribution system with DG, the fault current is increased because the DG is adding current source when a permanent fault occurs, and the protective devices in each other could not be coordinated. However, when SFCLs are applied into a power distribution system with DG, the coordination of protective devices could be accomplished. Therefore, to solve these problems, we analysed the operation of protective devices coordination in a power distribution system linked DG with SFCL.
다양한 디퓨저 형상의 유량 분배 특성에 관한 수치해석 연구
김명수(Myoung Soo Kim),김후배(Hoo Bae Kim),최형권(Hyoung Gwon Choi) 대한기계학회 2014 大韓機械學會論文集B Vol.38 No.9
본 연구에서는 개방형 축열시스템에 설치되는 다양한 형상을 가진 디퓨저의 유량 분배 특성을 수치해석 하였다. 작동유체가 분기배관의 양 방향으로 나뉘어져 있는 구멍들을 통하여 균등하게 분배되도록 4가지 형상의 디퓨저를 설계하였다. 상용 해석 프로그램인 ANSYS-FLUENT을 사용하여 비압축성 유체의 3차원 정상 층류 유동으로 시뮬레이션을 수행하였다. 한 방향 또는 양 방향으로 분배되는 디퓨저는 유량이 일정하게 분배되지 않는 반면에 양 방향 헤더 형식과 H형 대칭구조의 디퓨저는 균등한 분배특성을 보였다. 한편, H형 대칭구조의 디퓨저는 양 방향 헤더 형식 디퓨저보다 높은 펌프 양정을 필요로 하므로 유량분배도 일정하고 펌프 양정도 낮은 양 방향 헤더 형식 디퓨저가 최적임을 확인하였다. In this study, the distribution characteristics of diffusers with various shapes that are installed in an open-type thermal storage system are numerically investigated. Four diffusers are designed to distribute a working fluid evenly through the holes on bifurcated pipes. Three-dimensional steady simulations of incompressible laminar flow are conducted using commercial software (ANSYS-FLUENT). The simulation results show that both the bidirectional header-type diffuser and the H-type diffuser distribute the working fluid evenly whereas both the unidirectional and the bidirectional diffusers distribute the working fluid unevenly. The results also show that the H-type diffuser requires a higher head of pump than the bidirectional header-type diffuser. Therefore, the bidirectional header-type diffuser is recommended for use because it enables even distribution of the working fluid and requires a low head of pump.
배전계통에 초전도 전류제한기 적용 시 Recloser-Fuse 협조 방법
김명후(Myoung-Hoo Kim),김진석(Jin-Seok Kim),유일경(il-Kyoung You),문종필(Jong-Fil Moon),임성훈(Sung-Hun Lim),김재철(Jae-Chul Kim),안재민(Jae-Min Ahn) 대한전기학회 2009 대한전기학회 학술대회 논문집 Vol.2009 No.7
This paper shows us the analysis of the Recloser-Fuse coordination in power distribution system. Recloser has been installed with fuse to coordinate in power distribution system to protect against fault current efficiently. However, in power distribution system with SFCL, fault current couldn't be clear if occurred it as the operation of the Recloser-Fuse coordination couldn't be done. Therefore, this paper analysed the operation of the Recloser-Fuse coordination and found the method of the Recloser-Fuse coordination in power distribution system with SFCL using PSCAD/EMTDC.
소형 열병합발전 시스템이 연계된 배전계통에 초전도 전류제한기 적용시 리클로져-퓨즈 협조 분석
김명후(Myoung-Hoo Kim),김진석(Jin-Seok Kim),문종필(Jong-Fil Moon),임성훈(Sung-Hun Lim),김재철(Jae-Chul Kim),이준규(Joon-Kyu Lee) 대한전기학회 2010 전기학회논문지 Vol.59 No.3
This paper analyzed that the coordination of recloser-fuse when a superconducting fault current limiter (SFCL) is installed to a power distribution system linked small scale cogeneration system. As a rule, the recloser to properly protect against both permanent and temporary fault is installed to upstream of fuse. Therefore, in a power distribution system linked small scale cogeneration system, the fault current is increased by adding fault current of small scale Cogeneration system when a permanent fault occurs, and the fuse could melt during the first fast operation of the recloser because of more sufficient heat from the increased current. However, when SFCLs are applied into a power distribution system linked small scale cogeneration system, the coordination of recloser-fuse could be accomplished due to decreased fault current as the effect of the impedance value of the SFCL. Therefore, to solve these problems, we analysed the operation of recloser-fuse coordination in a power distribution system linked small scale cogeneration system with SFCL using PSCAD/EMTDC.
배전계통에 초전도 전류제한기 적용 시 Relcoser-Fuse 협조 방법에 관한 연구
김명후(Myoung-Hoo Kim),김진석(Jin-Seok Kim),유일경(Il-Kyoung You),문종필(Jong-Fil Moon),임성훈(Sung-Hun Lim),김재철(Jae-Chul Kim) 대한전기학회 2009 전기학회논문지 Vol.58 No.10
We analyze the problem of recloser-fuse coordination when a superconducting fault current limiter (SFCL) is installed to a power distribution system. Generally, The recloser is installed to upstream of fuse to protect against both permanent fault and temporary one appropriately. However, in a power distribution system with SFCL, the fault current is decreased by the effect of the impedance value of the SFCL and when a permanent fault occurs, the fuse may not melt during the last delay operation of the recloser because of the insufficient heat from the decreased current. Therefore, when SFCLs are applied into a power distribution system, the rating of the fuse has to be reselected to coordinate recloser to fuse effectively. To solve these problems, this paper analysed the operation of recloser-fuse coordination and presented the improved recloser-fuse coordination method in a power distribution system with SFCL using PSCAD/EMTDC.