• Title, Summary, Keyword: Energy storage system (ESS)

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Applying Hybrid Type Energy Storage System in AC High Speed Railway (하이브리드 타입 에너지 저장장치의 교류 고속철도 적용)

  • Jeon, Yong-Joo;Kang, Byoung-Wook;Chai, Hui-Seok;Kim, Jae-Chul
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.28 no.9
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    • pp.60-66
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    • 2014
  • In case of DC railway, value of ESS(Energy Storage System) is already approved. Whereas AC railway system, there are a lot of differences such as system design and operation pattern. Therefore there is doubt about AC ESS usefulness. Especially, regenerative energy can return to the source. So in case of AC 25kV system, it is necessary to consider different operation algorithm compare to DC railway system. In this paper ESS which is installed in AC high-speed railway was introduced. Power consumption pattern of High speed trains were analyzed, proper storage material was reviewed and operation algorithm was suggested. Super capacitor and Battery was used with hybrid type. Super capacitor was used to handle short term energy movement because of its prompt response and battery was used to handle long term energy movement because of its high energy density. Also in case of operation algorithm, phase control method was upgraded compare to voltage magnitude detection method.

Experimental Evaluation of an Energy Storage Device with High Rotaional Speed (에너지 저장용 고속회전기의 실험적 평가)

  • Lee, Jun-Ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.193-196
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    • 2014
  • Experimantal evaluation of an energy storage device with high rotational speed to store regenerative energy which might be generated during the braking period of the trains is presented. The proposed ESS is small scale model and has 5kW output power, high rotational speed. In general railway trains generate regenerative energy for 10-20 sec when the train brakes and also high traction energy is needed for very short moment (10 sec) when the train increases the traction force. Considering such characteristics of the railway system energy storage device for the railway should have very fast response property. Among the various energy storage devices flywheel energy storage system has the fastest response property, which means that flywheel ESS is the most suitable for the railway system.

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Coordinated State-of-Charge Control Strategy for Microgrid during Islanded Operation

  • Kim, Jong-Yul;Jeon, Jin-Hong;Kim, Seul-Ki
    • Journal of Electrical Engineering and Technology
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    • v.7 no.6
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    • pp.824-833
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    • 2012
  • In this paper, a coordinated state-of-charge (SOC) control strategy for the energy storage system (ESS) operating under microgrid islanded mode to stabilize the frequency and voltage was proposed. The proposed SOC control loop is made up of PI controller, which uses a SOC state of the energy storage system as an input and an auxiliary reference value of secondary control as an output. The SOC controller changes the auxiliary reference value of secondary control to charge or discharge the ESS. To verify the proposed control strategy, PSCAD/EMTDC simulation study was performed. The simulation results show that the SOC of the ESS can be regulated at the desired operating range without degrading the stabilizing control performance by proposed coordinated SOC control method.

Development of Battery Simulator for Performance Verification of MW-class PCS (MW급 PCS 성능검증용 배터리 모의장치 개발)

  • Lee, Jong-Hak;In, Dong-Seok;Heo, Nam-Eok;Park, Young-Min;Park, Ki-Won;Kwon, Byung-Ki
    • The Transactions of the Korean Institute of Power Electronics
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    • v.21 no.2
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    • pp.160-167
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    • 2016
  • An energy storage system (ESS) is applied to increase the energy efficiency of large plants or buildings that consume much energy, to improve the power quality of power systems, and to stabilize renewable energy source such as photovoltaic or wind turbine. The ESS is composed of a power conditioning system (PCS) and an energy storage. The battery is used as the energy storage. The battery is needed to design and verify a hardware and control system of PCS. Usually, a battery simulator is used instead of a battery, which is costly and hard to manage. In this paper, the development of the battery simulator for performance verification of the MW-class PCS is described. The battery simulator simulates the charging and discharging characteristics of batteries to design and verify the hardware and control system of PCS.

Optimal Power Control Strategy for Wind Farm with Energy Storage System

  • Nguyen, Cong-Long;Lee, Hong-Hee
    • Journal of Electrical Engineering and Technology
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    • v.12 no.2
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    • pp.726-737
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    • 2017
  • The use of energy storage systems (ESSs) has become a feasible solution to solve the wind power intermittency issue. However, the use of ESSs increases the system cost significantly. In this paper, an optimal power flow control scheme to minimize the ESS capacity is proposed by using the zero-phase delay low-pass filter which can eliminate the phase delay between the dispatch power and the wind power. In addition, the filter time constant is optimized at the beginning of each dispatching interval to ensure the fluctuation mitigation requirement imposed by the grid code with a minimal ESS capacity. And also, a short-term power dispatch control algorithm is developed suitable for the proposed power dispatch based on the zero-phase delay low-pass filter with the predetermined ESS capacity. In order to verify the effectiveness of the proposed power management approach, case studies are carried out by using a 3-MW wind turbine with real wind speed data measured on Jeju Island.

Analysis of the Cell Balancing Effect on the ESS Fire by Simulating the Euljiro 3-ga Subway ESS (을지로 3가 지하철 ESS를 모의한 ESS 화재에서 Cell Balancing이 미치는 영향성 분석)

  • Yun, Sang-Sun;Kee, Seok-Cheol
    • The Transactions of the Korean Institute of Power Electronics
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    • v.25 no.3
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    • pp.219-226
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    • 2020
  • Given the change in the energy market, large energy storage systems (ESS) is rapidly entering the market. In this rapid spread, fire accidents are becoming an issue. This study attempts to approach the fire from the system point of view to analyze the problems caused by bonding from different perspectives. Moreover, to conduct this study, the fabrication of real objects is dangerous, which needs to be verified through simulation. In this study, we approach the cause of fire that occurs in large-capacity ESS from the system perspective. We focus on determining the effects of cell balancing performed on the BMS after charging. Thus, we analyze the cell balancing behavior and the linkage risks to the various stacks. The study also explores why no fire occurs during 70% operation.

Analysis on Insulation and Protection Characteristics of Grid Connected ESS in Ground/Short-Circuit Fault (지/단락실증시험에서 MW급 계통연계형 ESS 절연/보호시스템 성능 분석에 관한 연구)

  • Kim, Jin-Tae;Lee, Seung-Yong;Park, Sang-Jin;Cha, Han-Ju;Kim, Soo-Yeol
    • KEPCO Journal on Electric Power and Energy
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    • v.6 no.2
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    • pp.119-122
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    • 2020
  • With recent ESS (Energy Storage System) fire accident, the fault protection performance is becoming more important. However, there has never been any experiments with the protection performance on the faults in the ESS system level. In this study, the effect of AC ground fault and IGBT (Insulated Gate Bipolar mode Transistor) short-circuit failure on MW class ESS was performed experimentally for the first time in the world. First of all, the effect of the AC single line ground fault on battery was analyzed. Moreover, the transient voltage was investigated as a function of the battery capacity and the power level. Finally, the breaking capability and insulation performance of ESS were examined under PCS short-circuit fault condition. Through the tests, it was found that ESS protection system safely blocked the faulty current regardless of the faults, whereas the electronic parts such as IGBT and MC (Magnetic Contactor) were broken by the fault current. Also, the electrical breakdown in ESS resulted from the transient voltage during the protection process.

Sizing of Energy Storage System for Grid-connected Microgrid by using Bisection Method (이분법을 활용한 계통연계형 마이크로그리드 에너지저장장치 용량산정)

  • Baek, Ja-Hyun;Ko, Eun-Young;Cho, Soo-Hwan;Kang, Tae-Hyuk
    • Proceedings of the KIEE Conference
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    • pp.639-640
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    • 2015
  • 본 논문에서는 일간 시간대별 에너지저장장치 (Energy Storage System, ESS) 최적 충 방전량 스케줄링을 이용하여 계통연계형 마이크로그리드 내에 설치되는 ESS의 용량을 산정한다. 대상 마이크로그리드의 과거 부하데이터를 이용하여 절감하고자 하는 양을 정하고, 이를 이용하여 전력변환장치(Power Conditioning System, PCS)의 정격출력량을 산정한다. ESS용량의 기준점을 정하여 이분법 적용구간을 설정하고, 반복연산을 통해 최적 ESS용량을 찾는 과정을 제시한다.

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Application of Energy Storage System for Industrial Customer (산업용 수용가의 에너지저장장치 적용)

  • Hong, Jong-seok;Chai, Hui-seok;Kang, Byoung-wook;Kim, Tae-hyeong;Kim, Jae-chul
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.7
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    • pp.992-998
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    • 2015
  • The ESS is composed of Battery Package, PCS(Power Conditioning System) Package, BCU(BESS Control Unit). In Jeju smart grid test-bed, we have developed a business model by ESS power system, renewable energy, transportation, such as customers, and have demonstrated above things. We have analyzed the EMS(Energy Management System) model of KPX where manages supply and demand of domestic electrical power system. We modified and launched EMS for microgrid but the cost was expensive and the system was large size. For releasing this system from industry as a whole, it is imperative to develop PMS(Power Management System) for microgrid. However, the cost of EMS for microgrid is expensive, some systems because it is a large development of the all of the first fruits in urgent PMS(Power Management System) for microgrid to be used in industry in general. Therefore, in this paper, we propose the ESS model considering the power systems characteristics and extensibility in korea. and also we propose the PMS to manage the ESS systems.

Improvement of Battery Charging Efficiency of ESS for Wind Power Application Using DC-AC Hybrid Charging Pattern (직교류 합성 충전 패턴을 이용한 풍력 연계용 ESS의 배터리 충전 효율 향상)

  • Lee, Jong-Hak;Song, Seung-Ho
    • The Transactions of the Korean Institute of Power Electronics
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    • v.22 no.4
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    • pp.330-335
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    • 2017
  • Increased fossil fuel consumption causes global warming, environmental pollution, and abnormal climate change. Wind-generated power installation is proposed to solve this problem. Recently, the wind power plant construction case encourages the installation of the energy storage system (ESS) to improve the intermittency of wind power. The maximized ESS operation profits connected to wind power are not generated in the simplest operation pattern of charging at night and discharging at day. The battery charging efficiency improvement should be considered to get more profits. Thus, there is a possibility of increasing ESS operation profits by analyzing the battery AC and DC charging/discharging efficiency and the yearly average sealed maintenance free (SMP) in hours. In this paper, the battery impedance characteristic, AC and DC charging/discharging efficiency, and the yearly average SMP are analyzed. The operation scenario to improve the ESS battery charging efficiency connected to wind power is proposed and verified via simulation.