• 제목/요약/키워드: Protection performance

검색결과 2,147건 처리시간 0.026초

AC Modeling of the ggNMOS ESD Protection Device

  • Choi, Jin-Young
    • ETRI Journal
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    • 제27권5호
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    • pp.628-634
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    • 2005
  • From AC analysis results utilizing a 2-dimensional device simulator, we extracted an AC-equivalent circuit of a grounded-gate NMOS (ggNMOS) electrostatic discharge (ESD) protection device. The extracted equivalent circuit is utilized to analyze the effects of the parasitics in a ggNMOS protection device on the characteristics of a low noise amplifier (LNA). We have shown that the effects of the parasitics can appear exaggerated for an impedance matching aspect and that the noise contribution of the parasitic resistances cannot be counted if the ggNMOS protection device is modeled by a single capacitor, as in prior publications. We have confirmed that the major changes in the characteristics of an LNA when connecting an NMOS protection device at the input are reduction of the power gain and degradation of the noise performance. We have also shown that the performance degradation worsens as the substrate resistance is reduced, which could not be detected if a single capacitor model is used.

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NAC Measurement Technique on High Parallelism Probe Card with Protection Resistors

  • Kim, Gyu-Yeol;Nah, Wansoo
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제16권5호
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    • pp.641-649
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    • 2016
  • In this paper, a novel time-domain measurement technique on a high parallelism probe card with protection resistors installed is proposed. The measured signal amplitude decreases when the measurement is performed by Needle Auto Calibration (NAC) probing on a high parallelism probe card with installed resistors. Therefore, the original signals must be carefully reconstructed, and the compensation coefficient, which is related to the number of channel branches and the value of protection resistors, must be introduced. The accuracy of the reconstructed signals is analyzed based on the varying number of channel branches and various protection resistances. The results demonstrate that the proposed technique is appropriate for evaluating the overall signal performance of probe cards with Automatic Test Equipment (ATE), which enhances the efficiency of probe card performance test dramatically.

Setting Considerations of Distance Relay for Transmission Line with STATCOM

  • Zhang, Wen-Hao;Lee, Seung-Jae;Choi, Myeon-Song
    • Journal of Electrical Engineering and Technology
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    • 제5권4호
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    • pp.522-529
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    • 2010
  • Distance relay plays an important role in the protection of transmission lines. The application of flexible AC transmission systems (FACTS) devices, such as the static synchronous compensator (STATCOM), could affect the performance of the distance relay because of compensation effect. This paper analyzes the application of distance relay on the protection of a transmission line containing STATCOM. New setting principles for different protection zones are proposed based on this analysis. A typical 500 kV transmission system employing STATCOM is modeled using Matlab/Simulink. The impact of STATCOM on distance protection scheme is studied for different fault types, fault locations, and system configurations. Based on simulation results, the performance of distance relay is evaluated. The setting principle can be verified for the transmission line with STATCOM.

A Probabilistic Approach to the Protection Capability Evaluation of Distance Relay in Transmission Systems

  • Zhang, Wen-Hao;Lee, Seung-Jae;Choi, Myeon-Song
    • Journal of Electrical Engineering and Technology
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    • 제5권3호
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    • pp.407-414
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    • 2010
  • This paper proposes a probability measure for the evaluation of relay performance from two aspects, namely, correct trip and no-unwanted trip. They are developed based on the relationship between relay settings and relay measurements, which follow a Gaussian probability model. The proposed method based on strict mathematical derivation is applied to protection capability evaluation of distance relays under various settings. Considering the specific attributes of each protection zone, the optimal settings are also determined accordingly. The protection capability could demonstrate clearly the relay performance under various settings and the optimal settings could provide good references for engineering applications.

Design of a Flight Envelope Protection System Using a Dynamic Trim Algorithm

  • Shin, Ho-Hyun;Lee, Sang-Hyun;Kim, You-Dan;Kim, Eung-Tae;Sung, Ki-Jung
    • International Journal of Aeronautical and Space Sciences
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    • 제12권3호
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    • pp.241-251
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    • 2011
  • Most large commercial aircrafts and high performance military aircrafts use fly-by-wire (FBW) or fly-by-light systems to improve their controllability, comfort, and safety. A flight envelope protection technique is used with flight control systems utilizing the FBW technique. Such flight envelope protection systems prevent these aircraft from exceeding the structural/aerodynamic limits and control their surface limits. This is accomplished by predicting the values of the future state variables and adaptively compensating the control action. In this study, the conventional dynamic trim algorithm of the flight envelope protection is modified to increase the method accuracy and to handle cases with multiple variables. Numerical simulation is also performed to verify the performance of the proposed method.

PSCAD/EMTDC를 이용한 송전선로 보호 계전기의 동특성 모델[1] (Dynamic-state Model[1] Transmission Line Protective Relay Using PSCAD/EMTDC)

  • 이홍학;김철환;조경보;장병태;이재욱;안상필;이재규
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 하계학술대회 논문집 A
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    • pp.348-350
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    • 2003
  • In recent years, with the continuous development of modem power system, the need for high performance protection to meet the customers' requests for more stable and reliable power supply has become increasingly emphasized. So, there is urgent need for a proper testing platform about not only existing digital protection relay but also new digital protection relay on the transmission line. It is also dynamic-state test which can test the performance of digital relay. This paper suggests basic system model for testing transmission line protection using PSCAD/EMTDC, and presents the process of the component modeling in the basic system.

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분산 독립형 변전소 종합 보호 제어 시스템 개발 (Development of Distributive Independent IDPACS(Integrated Digital Protection And Control System))

  • 고재학;조경래;안복찬;원희광;이권한;조남국;신희승
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 하계학술대회 논문집 B
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    • pp.919-921
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    • 1996
  • Recently, a growing demands on electricity require a high performance and reliable operation in the area of protection, control and monitoring of power plants and substations which may not provides with conventional systems. This paper describes a novel IDPACS (Integrated Digital Protection And Control System) in which we integrate all protection, control and monitoring function of the substations. The simulation results show that the proposed system provides fast response and reliable operation of power plant with superb performance on protection and control system.

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강구조 내화성능의 이론적 평가방법에 관한 조사연구

  • 성시창
    • 방재기술
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    • 통권20호
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    • pp.42-47
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    • 1996
  • Prior to real fire test, theoretical of the fire resistant performance of the structural ele-ments is often less time consuming and less costly to calculate it, than to determine the perform-ance experimentally. This study is aimed at introduction of estimating methods of the fire resistant performance of the steel structural elements not by the actual fire tests but by the mathematical models.

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신변보호사 자격검정 실기시험제도의 개선방안 (Improvement Plans for Protection Specialist Guard Certification Performance test System)

  • 강동범;김우준
    • 융합보안논문지
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    • 제16권1호
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    • pp.13-21
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    • 2016
  • 민간경비가 도입된 지 60여년이 지난 현재 민간경비와 관련된 국가공인 자격으로는 경비지도사와 신변보호사 자격제도가 있다. 본 연구에서는 2013년도부터 국가공인자격으로 실시 되어오고 있는 신변보호사 자격검정 사항 중에서 2차 실기시험제도의 문제점에 대하여 논의하였다. 현행 신변보호사 자격검정은 1차 학과시험과 2차 실기시험으로 분류하여 실시하고 있는 가운데 신변보호사의 자격 검증을 엄격히 하여 응시자에 대한 만족도와 대중의 신뢰도를 높여가야할 시기에 봉착하였다고 판단되어 신변보호사 실기시험제도의 문제점에 대한 개선방안을 다음과 같이 제시하였다. 첫째, 현재 단순하고 비교적 기초적인 실기시험 평가 항목의 난이도를 다양화 하여 구분하는 것이 필요하다. 둘째, 현재 실기시험 평가기술은 합기도의 기술분야에 치우쳐 있다고 볼 수 있어 각 무도분야의 실질적 활용가능성이 높은 기술을 복합적으로 접목시켜 다양화 하는 것이 필요하다. 셋째, 현재 일반화 되지 않은 실기시험 평가위원제도를 전문화된 실기시험 평가위원으로 선정할 수 있도록 기준안 마련이 필요하다. 넷째, 현재 실기시험 평가위원과 응시자의 관계에 있어 지인인 경우가 많아 객관성확보차원에서 제척제도를 신설하는 것이 필요하다. 이와 같이 신변보호사 자격검정 실기시험제도의 전문성을 고양시켜나가기 위해 관련기관의 제도적 개선이 시급히 이루어져야 할 것이다.

식물 품종 및 종자의 품질평가 기준에 대한 규정현황 (Legal Aspects for Quality Evaluation Standard of Plant Variety and Seed)

  • 최근진
    • 한국작물학회지
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    • 제47권
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    • pp.200-215
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    • 2002
  • There are some international standards and organization controling the quality characteristics of varieties and seeds such as UPOV, OECD, ISTA, AOSA. The National List system to check variety performance such as quality characteristics of plant varieties and seeds was established by each countries. The UPOV (International Union for the Protection of New varieties of Plant) regulates the requirement of plant variety protection that is distinctness (D), uniformity (U), stability (S) (here in after called DUS), Novelty and Denomination, and some quality characteristics are used to examine the requirement of plant variety protection by each crops. OECD (Organization for Economic Cooperation Development) seed scheme regulates the seed certification for seed trade between countries. ISTA (International Seed Testing Association) and AOSA(Association for Official Seed Analyst) regulates the seed analysis standard and methods. Most of the countries in Europe has the National List system, which check the value for cultivation and use(VCU), that is to say, variety performance such as yield, quality and stress to environment. All the seeds should be enlisted in the National List before sell the seed in their country. All the quality characteristics checked variety performance are for instance, amylose and amylopectin content in rice, molting quality, $\beta$-glucan, protein in barley, protein and sugar content in soybean, sugar and amylopectin content in corn etc. Conditions for the protection of new variety of plant are DUS. Quality characteristics may be the important characteristics and used to check DUS in crop by crop. It is very important to develop a new characteristics and establish standard method fur examine the VCU and DUS test for each crop.