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전산유체역학을 이용한 주파수 중첩에 의한 로그 웨이브 시뮬레이션
전우영(Wooyoung Jeon),박선호(Sunho Park) 한국해양환경·에너지학회 2021 한국해양환경공학회 학술대회논문집 Vol.2021 No.10
파랑 에너지가 한 점에 집중되어 발생하는 거대한 파랑 현상인 로그 웨이브(rogue wave)는 예측하기 어렵고 매우 높은 파도가 갑자기 나타나는 특징으로 인해 선박이나 해양 구조물 등의 안전을 위협하는 요인이 될 수 있다. 로그 웨이브는 서로 다른 주파수의 파랑이 한 점에 중첩되어 발생할 수 있다. 본 연구에서는 주파수 중첩에 의한 로그 웨이브에 대해 전산유체역학을 이용하여 수치파랑수조에서 재현하여 실험 결과와 비교하였다. 쇄파 형태에 따른 steep wave, spilling wave, plunging wave 세 가지 경우에 대하여 수치 방법이 결과에 미치는 영향을 확인하였다. Rogue wave, a giant wave phenomenon by focusing of wave energy, could be fatal to safety of ship or offshore platform because of its unpredictability and huge scale. Rogue wave could occur when waves with different frequency focused on a point. In this study, rogue wave occurred by frequency focusing was simulated in numerical wave tank using CFD. Three different types of breaking shape, steep wave, spilling wave and plunging wave were simulated and effects of numerical methods were investigated.
에너지전환 정책하에 전기차 수요자원의 경제적 가치 분석: 9차 전력수급계획 중심으로
전우영 ( Wooyoung Jeon ),조상민 ( Sangmin Cho ),조일현 ( Ilhyun Cho ) 한국환경경제학회·한국자원경제학회(구 한국환경경제학회) 2021 자원·환경경제연구 Vol.30 No.2
에너지전환 정책의 가속화로 변동성 재생에너지가 가파르게 증가하면서 계통수용비용이 빠르게 상승하고 있다. 변동성 재생에너지 증가는 기존 전통적 발전자원의 이용률을 하락시켜서 전력공급에 비효율성을 가중시키는데 이에 대한 해결책으로 수요자원이 주목받고 있다. 본 연구에서는 수요자원 중 큰 잠재력을 가지고 있는 전기차 수요가 재생발전에 대한 유연성 자원으로 활용될 경우 전력공급비용을 얼마나 경감시킬 수 있는지 9차 전력수급계획을 반영하여 분석하였다. 분석모형으로 재생발전의 확률적 특성을 사실적으로 반영할 수 있는 확률적 전력시스템 최적화 모형을 적용해서 재생에너지가 유발하는 비용과 전기차 수요자원의 편익을 분석하였다. 분석결과 계시별 요금제보다 가상발전소 기반의 직접제어방식이 편익이 더 높고, 발전구성에서 재생에너지의 비중이 높아질수록 편익이 더 높아지는 것으로 나타났다. 전기차 수요자원의 구현비용인 중개사업자 수수료와 배터리마모비용을 고려한 순편익 추정결과, 충방전이 가능한 가상발전소 방식의 경우 월평균 운행비용의 67~85% 수준으로 나타났다. 이러한 수요자원 순편익이 소비자에게 효과적으로 분배되는 요금체계가 적용될 경우 시장참여유인이 높을 것으로 추정된다. As variable renewable sources rapidly increase due to the Energy Transition plan, integration cost of renewable sources to the power system is rising sharply. The increase in variable renewable energy reduces the capacity factor of existing traditional power capacity, and this undermines the efficiency of the overall power supply, and demand resources are drawing attention as a solution. In this study, we analyzed how much electric vehicle demand resouces, which has great potential among other demand resources, can reduce power supply costs if it is used as a flexible resource for renewable generation. As a methodology, a stochastic form of power system optimization model that can effectively reflect the volatile characteristics of renewable generation is used to analyze the cost induced by renewable energy and the benefits offered by electric vehicle demand resources. The result shows that virtual power plant-based direct control method has higher benefits than the time-of-use tariff, and the higher the proportion of renewable energy is in the power system, the higher the benefits of electric vehicle demand resources are. The net benefit after considering commission fee for aggregators and battery wear-and-tear costs was estimated as 67% to 85% of monthly average fuel cost under virtual power plant with V2G capability, and this shows that a sufficient incentive for market participation can be offered when a rate system is applied in which these net benefits of demand resources are effectively distributed to consumers.
전우영(Wooyoung Jeon),모정윤(Jung Youn Mo) 한국신재생에너지학회 2017 신재생에너지 Vol.13 No.2
This study analyzed the cost of wind uncertainty by estimating the impact of various degrees of wind uncertainty on the operating cost of a power system. For the analysis methodology, this study used a simulation applying a stochastic form of security-constrained optimal power flow (SCOPF) based on the Jeju power system. To generate realistic wind generation input, a wind forecasting model based on an econometric time-series method was proposed in four major wind farms in Jeju Island. The result showed that the case with the deterministic wind reduces the operating cost most effectively. On the other hand, when the system faces stochastic wind forecasted 1 hour ahead, the amount of reserve required increases significantly. In addition, when the degree of wind uncertainty increases as the system operator conducts the day-ahead planning with the stochastic wind forecasted 4 hours ahead and 7 hours ahead, the amount of reserve required increases further and the amount of wind generation that the power system could adopt decreases, which leads to an increase in the overall operating cost.
A Study on Reserve Cost for adoption of VRE: Estimation of ORDC
Wooyoung Jeon(전우영) 한국에너지기후변화학회 2021 한국에너지기후변화학회 학술대회 Vol.2021 No.11
With increasing importance of achieving carbon neutrality, renewable sources are rapidly displacing fossil fuel generation. However, high variability and uncertainty of renewable energy undermine reliability of power supply, so it requires large amount of operating reserves as backup sources. In order to efficiently secure the proper level of reserve resources, it is essential to search the optimal price that reflect marginal social benefit and marginal cost of additional reserve resources by considering the probability and social cost of unstable power supply caused by renewable sources. This study estimates an operating reserve demand curve (ORDC) of Korea for varying penetration levels of renewable sources, which will help to provide foundation for proper value of reserve resources. For methodology, a stochastic form of power system optimization model called MPSOPF is used and stochastic characteristics of solar and wind generation are estimated based on econometric model and considered in the optimization. The result shows that ORDC in 2034 at 3000KRW/MW is 4.4 times higher than ORDC in 2020, which means that ORDC in 2034 is located far right compared to ORDC in 2020 due to massive renewable generation. In addition, it is estimated that under ORDC in 2034, lithium-ion battery, which is one of the most prominent back resources for renewable energy, is economically feasible but it is not under ORDC in 2020, which shows that proper valuation based on social benefit is important to secure reserve resources to socially-optimum level. Korean does not have a reserve market yet, but plan to initiate one by 2024 for efficient energy transition. This study contributes to provide an evidence for proper value and amount of reserve resources needed to efficiently accommodate renewable sources by 2034.