http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
철도전기실의 초박형 액체단열재 적용을 통한 에너지 절감효과
김형철(Hyungchul Kim),장정훈(Junghoon Jang),신승권(Sungkwon Shin),박용섭(Yongsub Park),김상암(Sangam Kim),김형래(Hyeong Rae kim),현병수(Byungsoo Hyun),김진호(Jinho Kim) 대한전기학회 2015 전기학회논문지 Vol.64 No.1
In this paper, because of global environmental problems such as energy shortage and abnormal climate, green energy development and energy saving technology development is being magnified. Heat insulation, the most basic and traditional energy saving method, is highly expected. Especially, simple and advanced heat insulation technique based on Nano material is promising future technology. The railway system also requires heat insulation. Especially, traditional heat insulator such as glass wool has been adopted frequently to rolling stock. The heat insulator is also adopted in general railway service buildings. Take account of cost-effective heat blocking performance, the heat insulator shall be adopted in diverse fields such as electric power, railroad, signal and communication. The only and direct solution for this problem is installing heat insulator with outstanding endurance, corrosion resistance and heat resistance to block outer heat Upgrading heat specification of equipment can be a solution, but since price and maintenance cost rise severely, this plan might be incongruous. In this research, energy saving effect of ultrathin heat insulator film was demonstrated by installing the film on roof of electrical room.
김형철(Hyungchul Kim),차준민(Junmin Cha),김진오(Jin-O Kim) 대한전기학회 2008 대한전기학회 학술대회 논문집 Vol.2008 No.10
RCM(reliability Centered Maintenance) 적용 시 나타나는 장점으로 인해 이미 여러 산업 분야에 적용되고 있다. 설비의 안정성을 중요시하는 원자력발전 부문에서 처음으로 도입 후 전력산업분야 대부분에서 RCM을 적용하거나 적용연구가 진행되고 있다. 철도산업에서도 전력산업 분야와 같이 안정적이면서 경제적인 전력을 공급하는 것이 중요하므로 정비업무의 중요성이 크다고 할 수 있다. 특히 철도 시스템 중 한전에서 154㎸나 345㎸를 수전 받아 철도 시스템에 전력을 공급하는 변전소의 역할은 매우 중요하다. 따라서 철도 변전소를 구성하고 있는 설비의 특성과 운영방식에 대한 연구를 통해 적절한 RCM적용 방안을 위한 고장모드 및 임계분석(FMECA: Failure Mode, Effects and Criticality Analysis) 연구의 필요성이 대두된다. RCM과 FMECA는 적용 산업분야에 따라 적용 절차를 다르게 적용되어진다. 따라서 철도 변전소에 대한 고장데이터와 설비들의 특성 및 현재 운용방식 등을 종합적으로 고려하여 적절한 수립방법 연구가 필요하다.
김형철(Hyungchul Kim) 대한전기학회 2013 전기학회논문지 Vol.62 No.8
In this paper, the analysis of inspection period bases on reliability is suggested in the field of traction power system. Even though there are several maintenance models, the most commonly used maintenance assessment has been focused on time based maintenance in real traction power systems. The maintenance intervals are selected on the basis of long-time experience. It ensures high availability and exact planning of staff. Reliability centered maintenance, which evaluates criticality and severity of each failure mode, achieves the operation, maintenance, and cost-effective improvement that will manage the risks of equipment. This paper deals with electrification in railway inspection frequency and applied reliability based inspection frequency instead of constant intervals. The distribution function of failure rate in traction power system belongs to Weibull function. Also, the fault data and the number of installed equipments for electrifications are collected. The failure history is investigated and classified in detail. Though these complicated procedures, it contribute to extend equipment lifetime and to reduce maintenance costs.
金炯徹(Hyungchul Kim),車濬敏(Junmin Cha),權世爀(Sae-hyuk Kwon) 대한전기학회 2006 전기학회논문지A Vol.55 No.5
The security analysis relates to the ability of the electric systems to survive sudden disturbances such as electric short circuits or unanticipated loss of system elements. It is composed of both steady state and dynamic security analyses, which are not two separate issues but should be considered together. In steady state security analysis including voltage security analysis, the analysis checks that the system is operated within security limits by OPF (optimal power flow) after the transition of a new operating point. On the other hand, dynamic security analysis deals that the transition will lead to an acceptable operating condition. Transient stability, which is the ability of power systems to maintain synchronism when subjected to a large disturbance, is a principal component in dynamic security analysis. Usually any loss of synchronism will cause additional outages. They make the present steady state analysis of the post-contingency condition inadequate for unstable cases. This is the reason of the need for dynamics of systems. Probabilistic criterion can be used to recognize the probabilistic nature of system components and shows the possibility of system security. A comprehensive conceptual framework for probabilistic static and dynamic assessment is presented in this paper. The simulation results of the Western System Coordinating Council (WSCC) system compare an analytical method with Monte-Carlo simulation (MCS). Also, a case study of the extended IEEE Reliability Test System (RTS) shows the efficiency of this approach.
50㎚ Thickness Gold Membrane Transducer
김형철(Hyungchul Kim),최준규(Junkyu Choi),김윤호(Yunho Kim),이성준(Sungjun Lee),신재하(Jaeha Shin),차미선(Misun Cha),이정훈(Junghoon Lee) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.5
This work deals with ultra-thin metal-based nano-mechanical transducers that have potentials for extraordinary sensitivity. This nano membrane transducer (NMT) consists of a flat thin film of gold with 30-60 ㎚ thickness freely suspended over large square openings with the side dimensions of 50-500 ㎛. This work involves the fabrication process and the testing method to obtain pressure sensitivity.