• 제목/요약/키워드: ESS optimal operation

검색결과 42건 처리시간 0.026초

Utilization of Energy Storage System based on the Assessment of Area of Severity in Islanded Microgrid

  • Lee, Kyebyung;Yoon, Minhan;Park, Chang-Hyun;Jang, Gilsoo
    • Journal of Electrical Engineering and Technology
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    • 제12권2호
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    • pp.569-575
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    • 2017
  • This paper proposes a method to utilize an energy storage system (ESS) based on the assessment of an area of severity (AOS) to voltage sag. The AOS is defined as a set of the fault positions that can cause voltage sags at many buses simultaneously. The assessment of AOS helps to determine an optimal location of ESS installation to minimize the expected sag frequency (ESF) at concerned buses. The ESS has the ability not only to play traditionally known roles but also to mitigate voltage sag impact on renewable energy sources (RES) in the islanded microgrid. Accordingly, using the proposed method the ESS has additional features to prevent the operation failure of RESs and improve the stability of the microgrid. In order to verify the presented method, a case study was conducted on the sample microgrid system that is modified from an IEEE 57-bus system.

고속철도 변전소 피크부하 저감용 ESS 일간 운전 프로그램 개발 (Development of Daily Operation Program of Battery Energy Storage System for Peak Shaving of High-Speed Railway Substations)

  • 변길성;김종율;김슬기;조경희;이병곤
    • 전기학회논문지
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    • 제65권3호
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    • pp.404-410
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    • 2016
  • This paper proposed a program of an energy storage system(ESS) for peak shaving of high-speed railway substations The peak shaving saves cost of equipment and demand cost of the substation. To reduce the peak load, it is very important to know when the peak load appears. The past data based load profile forecasting method is easy and applicable to customers which have relatively fixed load profiles. And an optimal scheduling method of the ESS is helpful in reducing the electricity tariff and shaving the peak load efficiently. Based on these techniques, MS. NET based peak shaving program is developed. In case study, a specific daily load profile of the local substation was applied and simulated to verify performance of the proposed program.

피크저감과 특례요금제를 고려한 ESS 경제성 분석 알고리즘에 관한 연구 (A Study on Economic Analysis Algorithm for Energy Storage System Considering Peak Reduction and a Special Tariff)

  • 손준호
    • 전기학회논문지
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    • 제67권10호
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    • pp.1278-1285
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    • 2018
  • For saving electricity bill, energy storage system(ESS) is being installed in factories, public building and commercial building with a Time-of-Use(TOU) tariff which consists of demand charge(KRW/kW) and energy charge(KRW/kWh). However, both of peak reduction and ESS special tariff are not considered in an analysis of initial cost payback period(ICPP) on ESS. Since it is difficult to reflect base rate by an amount of uncertain peak demand reduction during mid-peak and on-peak periods in the future days. Therefore, the ICPP on ESS can be increased. Based on this background, this paper presents the advanced analysis method for the ICPP on ESS. In the proposed algorithm, the representative days of monthly electricity consumption pattern for the amount of peak reduction can be found by the k­means clustering algorithm. Moreover, the total expected energy costs of representative days are minimized by optimal daily ESS operation considering both peak reduction and the special tariff through a mixed-integer linear programming(MILP). And then, the amount of peak reduction becomes a value that the sum of the expected energy costs for 12 months is maximum. The annual benefit cost is decided by the amount of annual peak reduction. Two simulation cases are considered in this study, which one only considers the special tariff and another considers both of the special tariff and amount of peak reduction. The ICPP in the proposed method is shortened by 18 months compared to the conventional method.

확률론적 방법론을 이용한 마이크로그리드(MG)의 에너지 저장장치(ESS) 최소 필요용량 및 투자시점 결정방법 (A Study on the Method to Evaluate Minimum Capacity of Energy Storage System(ESS) for Micro Grid(MG) Design)

  • 이재걸;신정훈;남수철;백승묵
    • 조명전기설비학회논문지
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    • 제24권8호
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    • pp.40-47
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    • 2010
  • Micro Grid(MG)는 새로운 개념의 전력시스템으로 Smart Grid 기술의 일환으로 관심을 받고 있다. 기본적인 MG의 개념은 신/재생에너지를 포함한 분산전원의 도입 및 효율적인 계통운영이지만 여기에는 전력공급의 신뢰성과 경제성이 배제될 수 없는 요소임은 확실하다. MG라는 새로운 계통의 개념을 도입하는데 있어서 기존 전력계통(Utility Grid)과의 간섭, 신뢰도 및 전력품질의 문제들이 해결해야 하는 숙제로 떠오르고 있는데 이에 대한 대안 중 하나가 에너지저장기술이다. 그러나 본 기술은 아직까지는 초기투자비 및 운영유지비가 매우 높은 수준이기 때문에 MG의 설계에 있어서 신뢰도와 경제성을 함께 고려한 Energy Storage System(ESS)의 설치방법이 필요로 된다. 이에 본 논문에서는 공급신뢰도기준을 충족할 수 있는 ESS의 최소필요용량 및 적정투자시점을 결정하는 확률론적 방법을 제안하고 이에 대한 사례연구를 수행하였다.

ESS 배터리 충방전 시스템을 위한 8kW급 LLC 절연형 컨버터 설계 (8kW LLC Isolated Converter Design for ESS Battery Charge/Discharge System)

  • 김진우;백승훈;조영훈;구태근
    • 전력전자학회논문지
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    • 제23권3호
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    • pp.161-167
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    • 2018
  • In battery-operated systems, an isolated converter is used to interface the utility grid with the system to increase stability when charging and discharging batteries. Systems such as vehicle-to-grids (V2Gs), on-board chargers, and energy storage systems (ESSs) have recently become popular, and the roles of isolated converters have become important considerations in fabricating such devices. A fixed-frequency LLC converter, which is a type of isolated converter, presents the advantages of high efficiency and high power density by performing zero-voltage switching (ZVS) over wide frequency ranges. However, the magnetizing inductance of the LLC converter should be designed to enable ZVS in all switching devices. Therefore, in this study, the operating characteristics of the LLC circuit are analyzed, and an optimal design method for ZVS operation is established. Moreover, an 8 kW LLC high-efficiency and high-power-density resonant converter is designed and tested for ESS application. The LLC converter achieves 98% efficiency at rated power.

신재생에너지가 연계된 마이크로그리드에서 에너지 저장장치의 최적 용량 선정에 관한 연구 (A Study on Optimal Capacity of Energy Storage System in Renewable Energy Based Micorgrids)

  • 김욱원;이남형;이윤성;신제석;김진오
    • 한국태양에너지학회:학술대회논문집
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    • 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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    • pp.529-533
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    • 2012
  • By introducing RPS(Renewable Portfolio Standard) for reduction of greenhouse gas, Renewable energy sources have becoming widespread gradually. However, Renewable energy sources, such as wind power and PV are difficult to control the output and they have intermittent characteristics of the output. These characteristics would cause some problems when it is connected in the power system. In order to solve these problems, Energy Storage Systems(ESS) are considered to use. Although there are many different storage devices, the utilization of Secondary Battery is the one of the best ways to stabilize an output fluctuation of RES because of its fast responsibility. For that reason, it would better fit a large-capacity of Secondary battery for stabilization. However, batteries cannot be installed with a large capacity blindly because of its expensive cost. So to select proper capacity of the battery is an important consideration. This paper presented a methodology for the optimal capacity and operation of ESS in microgrids.

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에너지 생산량 소비량 예측을 통한 효율적인 계통 독립형 ESS 제어 시스템 (Efficient Grid-Independent ESS Control System by Prediction of Energy Production Consumption)

  • 주종율;오재철
    • 한국전자통신학회논문지
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    • 제14권1호
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    • pp.155-160
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    • 2019
  • 본 논문에서는 신재생에너지와 농업ICT를 활용한 시설농업용 제어와 에너지생산량과 소비량 예측을 통해 효율적인 계통 독립형 ESS제어시스템을 제안한다. 제안된 시스템은 전력계통 정밀 위상 및 데이터를 시각화하여 유지보수 및 모니터링을 수행할 수 있는 통합 관리 시스템으로 장애 발생 시 자동으로 이에 대해 대처하고 데이터 수집, 처리, 제어가 가능하며, 태양광발전의 전력 발전과 설치된 설비들의 소비 패턴, 설비들의 동작 트랜드를 분석, 기상청 OpenAPI를 활용한 에너지 생산량 소비량 예측을 통해 최적의 에너지 운영 방법을 제시함으로써 불필요한 에너지 소비를 줄이고 운영비용을 절감할 수 있다.

독립형 마이크로그리드 내 분산전원별 최적용량 결정 방법 (Determining the Optimal Capacities of Distributed Generators Installed in A Stand-alone Microgrid Power System)

  • 고은영;백자현;강태혁;한동화;조수환
    • 전기학회논문지
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    • 제65권2호
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    • pp.239-246
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    • 2016
  • In recent years, the power demand has been increasing steadily and the occurrence of maximum power demand has been moving from the summer season to the winter season in Korea. And since the control of electric power supply and demand is more important under those situations, a micro-grid system began to emerge as a keyword for the sTable operation of electric power system. A micro-gird power system is composed of various kinds of distributed generators(DG) such as small diesel generator, wind turbine, photo-voltaic generator and energy storage system(ESS). This paper introduces a method to determine the optimal capacities of the distributed generators which are installed in a stand-alone type of microgrid power system based on the fundamental proportion of diesel generator. At first, the fundamental proportion of diesel generator will be determined by changing from 0 to 50 percent. And then we will optimize the capacities of renewable energy resources and ESS according to load patterns. Lastly, after recalculating the capacity of ESS with consideration for SOC constraints, the optimal capacities of distributed generators will be decided.

에너지 저장장치를 이용한 마이크로 그리드의 최적운영 및 신뢰도 지수 개선 (Optimal Operation Scheme and Reliability Index Improvement of Micro Grid Using Energy Storage Systems)

  • 김규호
    • 전기학회논문지
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    • 제63권2호
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    • pp.205-210
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    • 2014
  • The micro grid considered in this paper consists of a diesel generator, a photovoltaic array, a wind turbine, a fuel cell, and a energy storage system. This paper explains and simulates the micro grid components in terms of accuracy and efficiency of having a system model based on the costs of fuel as well as operation and maintenance. For operational efficiency, the objective function in a diesel generator consists of the fuel cost function similar to the cost functions used for the conventional fossil-fuel generating plants. The wind turbine generator is modeled by the characteristics of variable output. The optimization is aimed at minimizing the cost function of the system while constraining it to meet the customer demand and safety of micro grid. The operating cost in fuel-cell system includes the fuel costs and the efficiency for fuel to generate electric power. To develop the overall system model gives a possibility to minimize of the total cost of micro grid. The application of optimal operation can save the interruption costs as well as the operating costs, and improve reliability index in micro grid.

An Optimal Energy Storage Operation Scheduling Algorithm for a Smart Home Considering Life Cost of Energy Storage System

  • Yan, Luo;Baek, Min-Kyu;Park, Jong-Bae;Park, Yong-Gi;Roh, Jae Hyung
    • Journal of Electrical Engineering and Technology
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    • 제12권4호
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    • pp.1369-1375
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    • 2017
  • This paper presents an optimal operation scheduling algorithm for a smart home with energy storage system, electric vehicle and distributed generation. The proposed algorithm provides the optimal charge and discharge schedule of the EV and the ESS. In minimizing the electricity costs of the smart home, it considers not only the cost of energy purchase from the grid but also the life cost of batteries. The life costs of batteries are calculated based on the relation between the depth of discharge and life time of battery. As the life time of battery depends on the charge and discharge pattern, optimal charge and discharge schedule should consider the life cost of batteries especially when there is more than one battery with different technical characteristics. The proposed algorithm can also be used for optimal selection of size and type of battery for a smart home.