• Journal of Electrical Engineering and Technology
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• 제13권4호
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• pp.1407-1418
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• 2018

Novel mechanism of customized adequacy formulation is proposed in order to enhance micro grids system reliability. The mechanism accounts for 2-levles of load curtailment, and is mainly based on probabilistic load profile and hybrid Distributed Generation (DG) units modeling. The two load curtailments are needed in order to ensure adequate technical constraints at steady state condition during islanding mode of operation. The effectiveness of the proposed formulation has been verified using system independent analytical expressions for the evaluation of both reliability and Expected Energy Not Served (EENS) indices. The evaluation has examined the impact of different penetration levels of Hybrid DG Units in case study islands. Results show the enhancement of the overall distribution system reliability and the recommended conditions for successful islanding mode of operation.

• 조명전기설비학회논문지
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• 제23권4호
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• pp.47-55
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• 2009

본 논문에서는 해석적방법론에 의한 산업용 수용가의 공급지장비를 산정할 수 있는 방법론을 개발하기 위해 산업용 수용가 1,026호를 방문하여 설문조사를 수행하는 미시적 접근법을 사용하여 산업용 수용가의 종별 공급지장비를 표준산업분류에 의한 18개의 업종으로 조사하였다. 얻어진 조사결과를 계층화의사 결정법(AHP; Analytic Hierarchy Process)으로 최적의 공급지장비용 함수(SCDF; Sector Customer Demage Function)를 선정하였다. 이를 통하여 배전계통에서의 신뢰도 가치평가(VBDRA; Value Based Distribution Reliability Assessment)를 위해서 주어진 배전계통 예상 공급지장에너지(EENS; Expected Energy Not Supply), 정전비용기대치(ECOST; Expected Interruption Cost), 차단에너지비율(IEAR; Interrupted Energy Assessment Rate)을 계산하여 그 가치를 평가하였다. 이를 배전계통에 적용하기 위해서 사례연구로 적용하고 공급지장비용을 도출하여 그 특성을 분석하였다.

• 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).

• 대한전기학회논문지:전력기술부문A
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• 제55권11호
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• pp.453-462
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• 2006

This paper evaluates the reliability of KEPCO system using TRELSS, which is a probabilistic reliability evaluation program for large-scaled power system. In order to reflect the characteristic of KEPCO system, the sensitivity of reliability indices such as LOLP, EDLC, EENS and Energy Curtailment for variations of TRELSS parameter and input data was analyzed. Additionally, probabilistic reliability of KEPCO system reflecting sensitivity analysis results was systematically evaluated and simulated. Finally, maximum acceptable FOR of KEPCO system to satisfy reliability criterion, which meet in process of establishing the basic plan for long-term electricity supply and demand is suggested.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.61-62
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• 2007

This paper evaluates probabilistic reliability of KEPCO system using TRELSS, which is a probabilistic reliability evaluation program for large-scaled power system. In order to systematically evaluate probabilistic reliability of KEPCO system, contingency cases causing load loss in (N-1) & (N-2) contingency depth was analyzed and reliability indices such as LOLP, EDLC, EENS according to change of FOR was calculated.

• 전기학회논문지
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• 제59권1호
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• pp.26-32
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• 2010

This paper proposes a new effective installed reserve rate in order to evaluate reliability of power system considering renewable generators, which include uncertainty of resource supply. It is called EIRR(effective installed reserve rate) in this paper. It is developed with considering capacity credit based on ELCC by using LOLE reliability criterion. While the conventional installed reserve rate index yields over-evaluation reliability of renewable generators, the proposed EIRR describes actual effective installed reserve rate. However, it is not the probabilistic reliability index as like as LOLE or EENS but another deterministic effective reliability index. The proposed EIRR is able to evaluate the realistic contribution to the reliability level for power system considering wind turbine generators and solar cell generators with high uncertainty in resource supply. The case study in model system as like as Jeju power system size presents a possibility that the proposed EIRR can be used practically as a new deterministic reliability index for generation expansion planning or operational planning in future.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.578-579
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• 2007

The importance and necessity of conducting studies on area outage cost assessment have been increasingly important in recent years due to the competitive electricity market environment. The objective of operational issues would be to minimize the total area cost while satisfying all associated system constrains of each area[2]. This paper presents a methodology of the Area annual outage cost assessment by probabilistic reliability evaluation using TRELSS program for KEPCO system. The interrupted energy assessment rate (IEAR) is evaluated by macro approach that is using relations between GRDP and the electrical energy demand. The Expected Energy Not Supplied (EENS) of each area was evaluated using the Transmission Reliability Evaluation for Large-Scale Systems (TRELSS) Version 6_2, a program developed by EPRI are introduced in this paper.

• 조명전기설비학회논문지
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• 제29권8호
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• pp.83-89
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• 2015

This study suggests the methodology to decide the number and adequate capacity of substation transformer in a large-scale offshore wind farm (OWF). The recent trend in transformer capacity of offshore substation is analyzed in many European offshore wind farm sites prior to entering the studies. In order to carry out the economic evaluation for the transformer capacity we present the cost models which consist of investment, operation, and expected energy not supplied (EENS) cost as well as the probabilistic wind power model of wind energy that combines the wind speed with wind turbine output characteristics for a exact calculation of energy loss cost. Economic assessment includes sensitivity analysis of parameters which could impact the 400-MW OWF: average wind speed, availability, discount rate, energy cost, and life-cycle.

• 전기학회논문지
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• 제64권11호
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• pp.1535-1542
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• 2015

An increasing number of electric vehicles (EVs) in power system affects its reliability in various aspects. Especially under high EV penetration level, new generating units are required to satisfy system's adequacy criterion. Wind power generation is expected to take the major portion of the new units due to environmental and economic issues. In this paper, the system reliability is analyzed using Loss of Load Expectation (LOLE) and Expected Energy Not Served (EENS) under each and both cases of increasing wind power generation and EVs. A probabilistic multi-state modeling method of wind turbine generator under various power output for adequate reliability evaluation is presented as well. EVs are modeled as loads under charging algorithm with Time-Of-Use (TOU) rates in order to incorporate EVs into hour-to-hour yearly load curve. With the expected load curve, the impact of EVs on the system adequacy is analyzed. Simulations show the reliability evaluation of increasing wind power capacity and number of EVs. With this method, system operator becomes capable of measuring appropriate wind power capacity to meet system reliability standard.

• 한국지진공학회논문집
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• 제10권3호
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• pp.13-20
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• 2006

전력송전시스템에서 변전소는 에너지공급의 효율성을 높이기 위하여 다수의 변압기를 동시에 운영하는 병렬 운전을 한다. 이 논문에서는 변압기의 병렬 운전 방식을 고려하여 변전소를 다중피해상태로 모사할 수 있는 신뢰성 해석 방법을 개발하였다. 그리하여 변전소의 다중피해상태를 고려한 전력망의 지진 신뢰도 평가 결과를 파괴와 생존의 이중피해상태만을 고려한 기존의 신뢰도 평가 결과와 비교하였다. 몬테 카를로 방법을 사용한 국내 345kV 전력망에 대한 지진 신뢰성 평가 결과, 망 전체의 신뢰성 지수들은 이중 및 다중피해 상태에 의한 망 전체의 피해정도 차이가 그다지 크지 않음을 나타내었다. 수요절점신뢰성 지수에서는 이중피해상태만을 고려한 피해정도 가 다소 높게 나타나는 경향이 있었다. 특히 이중피해상태에 의한 공급 지장 전력량 기대치는 다중피해상태에 의한 것보다 상당히 높게 나타났다.