http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
조성철,엄주홍,이태형,Cho, Sung-Chul,Eom, Ju-Hong,Lee, Tae-Hyung 한국조명전기설비학회 2007 조명·전기설비학회논문지 Vol.21 No.8
가스방전관(GDT)은 내부 정전용량이 작아서 통신용 서지보호기로 널리 사용되고 있는 소자이다. 하지만 가스방 전관의 동작개시를 위해서는 방전이 개시될 수 있는 충분한 전압과 시간이 필요하며, 이 동작개시전압은 피보호 회로가 서지에 민감한 장비일 경우 손상을 줄 수 있을 만큼 크므로 최근에는 조합 형태로 적용하는 경우가 대부분이다. 이렇게 초기 과전압이 상당 부분 존재하는 가스방전관에는 추가적으로 TVS나 필터 등을 통해 피크 전압을 제한해 주어야 한다. 본 논문에서는 공통모드 초크코일을 이용한 필터를 적용하여 공통모드와 차동모드의 조합회로를 구성하고, 주파수 대역이 다른 뇌임펄스 전압과 ring wave 전압을 인가하여 파형에 따른 조합회로의 특성을 확인하였다. 다단으로 보호되는 과정을 각각의 측정점에서 잔류전압을 측정하여 단계별로 적용한 SPD들이 어떻게 동작하는지를 실측데이터로 제시하였다. 각 단계의 잔류전압을 비교했을 때 공통모드에 비하여 차동모드에서 서지전압을 제한하는 성능이 보다 효과적이다. Gas Discharge Tubes (GDTs) are widely used as surge protectors for communication applications due to their small internal capacitance. In these days, however, they are mostly used in combined configurations, because the sparkover voltage required to initiate the discharge process in the GDTs and the time taken for arc formation process can be large enough to damage to sensitive circuits. For GDTs with a considerably high initial residual voltage, we should limit the peak voltage using a TVS or filter. We made a hybrid SPD circuits of common-mode type and differential-mode type with the filter using common-mode choke. Also, we applied lightning impulse voltage and ring wave voltage which frequency bandwidth are different each other and verified the characteristics of hybrid SPD circuits according to waveshapes. We describe how the applied SPDs operate in protection process steps with the actual data obtained from the residual voltage measurement at each step. The experiment results show that the surge voltage reduction with the choke coil is more effective in differential-mode circuit than in common-mode circuit.
조성철(Sung-Chul Cho),이태형(Tae-Hyung Lee),엄주홍(Ju-Hong Eom),이복희(Bok-Hee Lee) 한국조명·전기설비학회 2011 한국조명·전기설비학회 학술대회논문집 Vol.2011 No.11
Distribution characteristics of conductive EMI currents by lightning in the structure was presented in this paper. To analyze a distribution of conductive currents, both experiment using the real size structure model and simulation using CDEGS HIFREQ program were performed. Test conditions which was possible to be appled to an installation method were considered. In results, some installation methods were effective at reducing conductive EMI currents flowing along vertical and horizontal rods in structure.
공통 접지시스템에서 뇌격전류의 분류율 계산을 위한 등가접지임피던스
조성철(Sung-Chul Cho),이태형(Tae-Hyung Lee),엄주홍(Ju-Hong Eom),이복희(Bok-Hee Lee) 한국조명·전기설비학회 2011 한국조명·전기설비학회 학술대회논문집 Vol.2011 No.5월
This paper presents a new method for calculating the distribution ratio of lightning current between each current sharing paths in common grounding system, which is need to allow for the equivalent grounding impedance. The equivalent grounding impedance calculated with the equivalent frequency of lightning current includes the transient characteristics of the grounding electrode considering circuit parameters of R, L, C, G. When the calculated distribution rates are compared with test results, the method using the equivalent grounding impedance is more effective than the method using only the grounding resistance.
100㎄의 최초 단시간 뇌격전류 발생기술의 신뢰성 향상 기법
조성철(Sung-Chul Cho),이태형(Tae-Hyung Lee),권기량(Ki-Rayng Kwon),엄주홍(Ju-Hong Eom) 대한전기학회 2010 대한전기학회 학술대회 논문집 Vol.2010 No.11
This paper presents some methods for improving reliability of technology to generate first short stoke lightning current of 100 ㎄. In order to improve reliability for both operating crowbar switch and spark gap of ICG, the developed optic-driven system was used. Also a damping resistor and a multi-stage coil were used to satisfy the tolerance of current parameter. In result, the probability of success in generating lightning current was increased. Using the developed first short stroke lightning current generator, 100 ㎄ impulse current of 10/350 ㎲ was generated successfully.