• 전기학회논문지
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• 제62권8호
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• pp.1066-1073
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• 2013

This paper illustrates newly an outage cost impact index function(OCIIF). The assessment of the OCIIF is described using the Web Based Online Real-time Outage Cost Assessment and Information System(WOROCAIS) for power system outage cost assessment in Korea. The proposed OCIIF is not absolute but relative outage cost impact index function in view point of outage time using web based survey method for outage cost assessment. While conventional methodology does not consider short time outage cost assessment, the proposed OCIIF reflects short time outage. SCOF(Sector Customer Outage Function) in stead of the traditional SCDF(Sector Customer Damage Function) is defined and proposed newly in this paper. Based the SCOF, AVLL(Average Value of Loss Load) is newly proposed. The OCIIF is demonstrated by WOROCAIS in case study around 2,000 sample data surveyed by KEPCO in South Korea in recent.

• Journal of Electrical Engineering and Technology
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• 제2권2호
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• pp.201-207
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• 2007

As the power industry moves towards open competition, there has been a need for methodology to evaluate distribution power system reliability by using customer interruption costs, particularly in power supply zones under the competitive electricity market. This paper presents an algorithm to evaluate system average interruption duration index, expected energy not supplied, and system outage cost taking into consideration failure rate of the distribution facility and industrial customer interruption cost. Also, to apply this algorithm to evaluate system outage cost presented in this paper, the distribution arrangement of a dual supply system consisting of mostly high voltage customers in an industrial complex in Korea is used as a sample case study. Finally, evaluation results of system interruption cost, system average interruption duration index, and expected energy not supplied in the sample industrial complex area are shown in detail.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 A
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• pp.107-109
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• 2004

It is very important to operate a power system safely. An fault may causes the cascading outages in power system. Use of systematic, precise definitions related to the outages is essential for meaningful exchange of data. Moreover, it is necessary that specific instructions for reporting outages is developed. This paper presents the outage management for a power system. The outage managements of the many utilities are researched, which include the definition, classification, index and report of outage. Finally, the outage management standard is proposed, and the necessity and structure of KERC(Korean Electric Reliability Council) are presented

• 정보처리학회논문지C
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• 제10C권1호
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• pp.111-118
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• 2003

정보화 시대가 도래하면서 통신망의 장애에 의한 서비스 단절은 사회 각 분야에 치명적인 영향을 끼치게 된다. 통신망 장애에 의한 피해를 계량적으로 평가할 때 서비스를 이용하는 가입자 측면에서 살펴보면 얼마나 많은 장비가 장애에 의해 피해를 입었는가 하는 것보다는 얼마나 많은 가입자가 얼마나 오랫동안 서비스를 이용하지 못하였는지가 더 중요할 것이다. 따라서, 본 논문에서는 국내 무선통신망의 장애발생시 가입자에 대한 충격정도를 정량적으로 산출하여 장애영향을 평가할 수 있는 장애영향 평가 모델에 대하여 제안하였다. 이때, 국내 무선통신망 환경에 적합한 장애영향 평가 모델을 제안하기 위하여 국내 무선통신망의 가입자수, 무선서비스 유형별 중요도에 따른 가중치를 고려하였고 장애에 의해 영향 받은 가입자수를 계량화하는 크기 비중 값 계산식을 개발, 적용하였다. 장애영향 평가 모델의 적용결과를 살펴보면 PCS 네트워크에서 30,000명의 가입자가 30분 동안 "Mobile to Land" 서비스를 제공받지 못했을 경우 장애지수는 2.5로서 10,000명의 가입자가 서비스를 제공받지 못한 경우의 0.5 보다 5배 정도 가입자에게 충격을 주는 것으로 나타났으며, 30,000명의 가입자가 30분 동안 "Mobile to Land" 및 "Local Mobile to Mobile"의 서비스를 동시에 제공받지 못했을 경우는 3.75 이었다.비스를 동시에 제공받지 못했을 경우는 3.75 이었다.

• 전기학회논문지
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• 제59권10호
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• pp.1703-1711
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• 2010

Electric power utilities are facing increasing uncertainties regarding the economic, political, societal, environmental constraints under they operate and plan their future systems. The utilities have to integrate consumers' interruption cost representing reliability worth of electricity into the process of determining the optimum investment level. In order to do so, the estimated outage cost must be included into quantitative index corresponding to system capital and operation investment cost to establish an optimal expansion plan. This paper is a study on the outage cost assessment by using macro approach for calculating IEAR(Interrupted Energy Assessment Rates) and the TRELSS(Transmission Reliability Evaluation for Large-Scale Systems) program was used to calculate EENS(Expected Energy Not Served).

• 전기학회논문지
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• 제65권8호
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• pp.1317-1325
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• 2016

This paper identifies the issues of contingency analysis for restoration in distribution systems. Contingency analysis has been applied to transmission systems but not to distribution systems. The distribution system is different from transmission system. So it is hard to apply for existing contingency analysis to distribution system. In this paper, a new contingency analysis method for distribution systems is proposed. The proposed method is based on service restoration capability. It aims to minimize outage left after service restoration in case of a fault in advance. The method estimates the vulnerability which is represented by zone restoration index proposed in [1]. Applying the proposed method, operators could change the system so that it does not leave any outage left after restoration. Case study has been carried out on a five feeder system and its results show effectiveness of the method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 A
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• pp.381-383
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• 2004

This paper presents for service restoration Abstract -in electric power distribution systems. The aim of the service restoration is an emergency control in distribution system to restore out-of service areas as soon as possible when a fault occurs in distribution system. For this reason, this paper presents a new service restoration strategy for multi-outage areas. Proposed algorithm consists of two methods. One is individual restoration scheme, the other one is integrated restoration scheme. The former determines restoration order of outage areas based on restoration index. If the former method can not generate a feasible restoration plan, the latter would try to find new configuration without overloaded section through tie exchange method.

• 대한전기학회논문지:전력기술부문A
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• 제48권10호
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• pp.1198-1205
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• 1999

This study is focused on the reliability evaluation for distribution system based on deterministic evaluation technique. Average failure rates, average outage time, and average annual outage time of electrical parts and load points are calculated through network reduction method and failure mode & effective analysis method. And reliability indices of distribution system are calculated. Finally, by employing analytic hierarchy process method, unique index which evaluates and improves the distribution system is calculated. As a result, finding weak points and expansion schedule of the system is possible. The usefulness of this method is verified by applying it to the Inchon International Airport.

• Journal of Astronomy and Space Sciences
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• 제37권4호
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• pp.219-228
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• 2020

A CubeSat platform has become a popular choice due to inexpensive commercial off-the-shelf (COTS) components and low launch cost. However, it requires more power-efficient and higher-data rate downlink capability for space applications related to remote sensing. In addition, the platform is limited by the size, weight and power (SWaP) constraints as well as the regulatory issue of licensing the radio frequency (RF) spectrum. The requirements and limitations have put optical communications on promising alternatives to RF communications for a CubeSat platform, owing to the power efficiency and high data rate as well as the license free spectrum. In this study, we analyzed the performance of optical downlink communications compatible with CubeSat platforms in terms of data rate, bit error rate (BER) and outage probability. Mathematical models of BER and outage probability were derived based on not only the log-normal model of atmospheric turbulence but also a transmitter with a finite extinction ratio. Given the fixed slot width, the optimal guard time and modulation orders were chosen to achieve the target data rate. And the two performance metrics, BER and outage data rate, were analyzed and discussed with respect to beam divergence angle, scintillation index and zenith angle.

• 대한전자공학회논문지TC
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• 제46권5호
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• pp.122-129
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• 2009

본 논문에서는 다중 세션을 가진 PoC서비스 환경 하에서 시변의 무선 채널의 상황을 고려하여 각 세션 참여자들의 무선채널의 품질을 일정한 수준이상으로 보장할 수 있도록 전송속도를 조정하는 방안을 제안하고 이탈(Outage)확률을 성능지수로 하여 다경로 무선채널환경 하에서 제안한 방법과 기존방법간의 성능 차이를 비교 분석한다. 다경로 환경 하에서 신호 대 잡음비의 분포함수를 유도하고 이로부터 이탈확률을 유도하고, 기존방법과 제안한 방법을 비교한 결과, 제안된 방법을 사용하였을 경우 서비스 품질을 특징짓는 이탈확률이 대폭 감소하였으며 다경로의 수에 따른 다이버시티(diversity) 이득이 매우 커지며 이에 따른 이탈확률의 개선이 두드러지게 나타남을 확인하였다.