• Transactions of the Korean hydrogen and new energy society
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• v.32 no.6
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• pp.477-482
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• 2021

Hydrogen production, hydrogen production cost, and utilization rate were calculated assuming four cases of hydrogen production system in combination of photovoltaic power generation (PV), water electrolysis system (WE), battery energy storage system (BESS), and power grid. In the case of using the PV and WE in direct connection, the smaller the capacity of the WE, the higher the capacity factor rate and the lower the hydrogen production cost. When PV and WE are directly connected, hydrogen production occurs intermittently according to time zones and seasons. In addition to the connection of PV and WE, if BESS and power grid connection are added, the capacity factor of WE can be 100%, and stable hydrogen production is possible. If BESS is additionally installed, hydrogen production cost increases due to increase in Capital Expenditures, and Operating Expenditure also increases slightly due to charging and discharging loss. Even in a hydrogen production system that connects PV and WE, linking with power grid is advantageous in terms of stable hydrogen production and improvement of capacity factor.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.6
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• pp.1339-1348
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• 2021

There are variety of reasons for renewable energy curtailment, including lack of transmission availability and grid system stability. In the Jeju island region, there are many cases in which the supply of electricity is already increased compared to the demand for electricity due to the increase of solar and wind power generation facilities, and accordingly, the number of curtailments for wind power generation is increasing. This research aims to find the direction of efficient reception of renewable energy and stable operation of the power system using HVDC(High Voltage Direct Current) and BESS(Battery Energy Storage System) facilities that are in charge of power supply in Jeju island. And the paper suggests a practical operation plan for optimal system operation, and the direction of system operation of the land power system due to the expansion of solar and wind power generation facilities in the future.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.4
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• pp.566-572
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• 2013

A microgrid is a small scale power system. The microgrid is operated in two operation modes, the grid-connected mode and the islanded mode. In the islanded mode, the frequency of a microgrid should be maintained constantly. For this, the balance between power supply and power demand during islanded mode should be met. In general, energy storage systems (ESSs) are used to solve power imbalance. In this paper, the frequency control effect of a Lithium-ion battery energy storage system (Li-ion BESS) has been tested on the hardware-in-the loop simulation (HILS) system environment.

• KEPCO Journal on Electric Power and Energy
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• v.1 no.1
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• pp.29-32
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• 2015

Since the characteristics of Renewable Energy Sources like wind turbine generators are very different from those of existing thermal power generators and their response to the sudden change of the frequency are not as good as that from thermal power generators. Especially when the penetration level of the wind power generation is substantially high, the output from the WTG would be possibly limited to keep the stability of power systems. For this, this paper implements the process for calculating the dynamic penetration limit of WTG and analyze the potential application of BESS for increasing the dynamic penetration limit of WTG.

• Journal of Power Electronics
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• v.10 no.5
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• pp.538-547
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• 2010

This paper deals with a stand-alone wind energy conversion system (WECS) with an isolated asynchronous generator (IAG) and voltage and frequency (VF) control feeding three-phase four-wire loads. The reference generator currents are estimated using the instantaneous symmetrical component theory to control the voltage and frequency of an IAG system. A three-leg voltage source converter (VSC) with an isolated star/delta transformer is used as an integrated VSC. An integrated VSC with a battery energy storage system (BESS) is used to control the active and reactive powers of the WECS. The WECS is modeled and simulated in MATLAB using the Simulink and the Sim Power System (SPS) toolboxes. The proposed VF controller functions as a voltage and frequency regulator, a load leveler, a load balancer and a harmonic eliminator in the WECS. A comparison is made on the rating of the VSC with and without ac capacitors connected at the terminals of an IAG. Simulation and test results are presented to verify the control algorithm.

• Proceedings of the KIPE Conference
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• 2014.11a
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• pp.93-94
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• 2014

본 논문의 주제는 가파도 마이크로 그리드에 적용한 1MVA급 배터리 에너지 저장시스템(BESS-Battery Energy Storage System)을 소개하는 것이다. 에너지 저장장치가 디젤발전기와의 연계 및 독립운전 하여 탄소 배출 없이(Carbon-Free) 가파도 전체 부하에 전원을 공급하는 실증 사례를 살핀다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.6
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• pp.727-737
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• 2014

This paper presents the design of Fuzzy PI controller that is used at BESS(Battery Energy Storage System) charging and discharging process for islanded operation in microgrid. Most of the PI controllers have fixed PI gains, but real-time updated gains are applied to PI controller using Fuzzy logic in this paper. The performances of suggested Fuzzy PI controller are simulated by PSCAD/EMTDC. As a result, output characteristics of ESS applied real-time updated gains to PI controller are faster than those of using fixed gains.

• 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.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.1
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• pp.38-45
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• 2018

In September 2016, the government decided to apply a REC 5.0 weighting to solar-battery ESS to increase the supply of renewable energy. In this paper, we calculated the optimal capacity of battery ESS which maximizes the revenue when solar is linked with battery ESS. In the case study, the optimal capacity was calculated by applying the conservative REC price, and we studied sensitivity analysis about battery price and real-time REC price.

• Proceedings of the KIPE Conference
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• 2011.11a
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• pp.163-164
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• 2011

본 논문은 스마트그리드용 배터리 에너지 저장장치(Battery Energy Storage System, BESS)와 같은 대용량 전력변환장치의 개발 및 성능검증 시험에 사용된 대용량 시험설비에 대해 기술하였다. 대용량 시험설비는 모의 수 배전 계통 설비, DC Power Supply, 부하설비로 구성되어 있다. 모의 수 배전 설비는 개발 시험규격과 계통 상황을 모의하고, DC Power Supply는 연료전지나 배터리 등의 DC Source, 수동부하장치는 전력 변환 설비의 각종 부하들을 모의하기 위해 설계 제작하여 스마트그리드용 2MVA BESS의 성능검증 시험에 이용하고 있다.