• KEPCO Journal on Electric Power and Energy
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• v.6 no.3
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• pp.315-319
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• 2020

The modern transportation and mobility sector is expected to encounter high penetration of Electric Vehicles (EVs) because EVs contribute to reducing the harmful emissions from fossil fuel-powered vehicles. With the prospective growth of EVs, sufficient and convenient facilities for fast charging are crucial toward satisfying the EVs' quick charging demand during their trip. Therefore, the Fast Electric Vehicle Charging Stations (FECS) will be a similar role to gas stations. In this paper, we study a charging scheduling problem for the FECS with solar photovoltaic (PV) and an Energy Storage System (ESS). We formulate an optimization problem that minimizes the operational costs of FECS. There are two cost and one revenue terms that are buying cost from main grid power, ESS degradation cost, and revenue from the charging fee of the EVs. Simulation results show that the proposed scheduling algorithm reduces the daily operational cost by effectively using solar PV and ESS.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.67 no.2
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• pp.94-99
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• 2018

Depending on how the energy storage system(ESS) is used in a system that can construct a microgrid by using an independent power source such as campus, surplus power can be generated that can not be charged to the ESS. For example, assuming that heat is supplied by a fuel cell in the case of a system in which thermal self-sustaining is prioritized, the fuel cell capacity required differs depending on the heat load. The amount of surplus power that can not be stored in the ESS will appear differently depending on the load operation of the fuel cell for each cycle. This power is hydrogenated through a water electrolytic device to present the amount of hydrogen energy that can be operated for each cycle. Therefore, this paper propose the possibility of utilizing University campus as a hydrogen station.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.6
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• pp.885-891
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• 2017

The energy storage system(ESS) is a core component for exchanging the power system structure of the unidirectional power flow into a bidirectional structure. Its important role has been increasing because it has multiple functions such as output stabilization of new renewable energy, demand management, frequency regulation, etc. However, the performance evaluation technology of ESS in korea is lower than one of advanced countries and the recognition of standardization is also lack compared to advanced countries. Furthermore, in order to more accurately and reliably validate the performance of the ESS in advanced countries, it has been required to perform not only performance testing by H/W devices but also performance verification by S/W tool. Therefore, in order to verify the performance testing of ESS by S/W tool, this paper proposes the modeling method of performance testing devices for MW scaled ESS by using the PSCAD/EMTDC S/W, based on real testing devices in domestic institute. From the simulation results of proposed modeling method, it is confirmed that the proposed modeling method is a useful tool for performance validation of ESS.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.12
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• pp.2190-2195
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• 2011

Due to enhanced demands on quality, security and reliability of the electric power energy system, a microgrid has become a subject of special interest. In this paper, output characteristics of energy storage system (ESS) with an electric double layer capacitor (EDLC) and battery energy storage system (BESS) of a renewable energy based microgrid were analyzed under grid-connected and islanded operation modes. The microgrid which consists of photovoltaic and wind power turbine generators, diesel generator, ESS with an EDLC, BESS and loads was modeled using real time digital simulator. The results present the effective control patterns of the microgrid system.

• Journal of the Korea Society of Computer and Information
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• v.23 no.10
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• pp.57-63
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• 2018

The operating system for an isolated microgrid, which is completely disconnected from the central power system, aims at preventing blackouts and minimizing power generation costs of diesel generators through efficient operation of the energy storage system (ESS) that stores energy produced by renewable energy generators and diesel generators. In this paper, we predict the amount of renewable energy generation using the weather forecast and build an optimal diesel power generation plan using a genetic algorithm. In order to avoid inefficiency due to inaccurate prediction of renewable energy generation, our search algorithm imposes penalty on candidate diesel power generation plans that fail to maintain the SOC (state of charge) of ESS at an appropriate level. Simulation experiments show that our optimization method for maintaining an appropriate SOC balance can prevent the blackout better when compared with the previous method.

• Journal of the Korea Convergence Society
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• v.9 no.3
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• pp.31-37
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• 2018

Energy Storage System(ESS) is a system that maximizes energy efficiency by selectively storing and using the generated power when needed. Therefore, energy must be able to be charged or supplied at any time, and non-operating time should be minimized even in the case of failure or maintenance. However, current large-capacity energy storage systems must be shut down during maintenance due to structural problems. In this paper, we propose a PCS for 1MW ESS by configuring modular for large capacity ESS in parallel and verified of the hot swap technology that can replace, change, and repair the components that make up the system while keeping the system operating.

• Journal of Energy Engineering
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• v.29 no.1
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• pp.44-51
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• 2020

The importance of ESS has been emphasized due to stabilization of power demand due to deterioration of network reliability and expansion of renewable energy sources. ESS (Energy Storage System) stores the remaining power and uses it when necessary to meet the power demand, and build the ESS system mainly in conjunction with solar and wind power. In this paper, we propose a home PV Charging Module using the Master-Slave method which is effective for low insolation. After designing the module, Fast MPPT algorithm is applied to generate the maximum output from the nonlinear output characteristics of the PV modules. The average power value for the input of PV Charging Module was 296.90 W and the output power was 289.60 W, which averaged 97.54%.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.619-620
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• 2015

본 논문은 독립형 마이크로그리드 환경에서의 신재생에너지원의 출력 안정화 및 디젤발전기의 최소 사용을 통한 경제적인 운영을 위해 필요한 ESS(Energy Storage System)의 도입을 위한 용량 산정 및 SOC에 따른 충/방전 알고리즘을 제안한다. 제안한 산정 알고리즘을 통해 도서지역의 독립형 마이크로그리드의 데이터를 활용하여 ESS 용량을 산정하고, 이에 대한 효과를 검증한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.3
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• pp.596-606
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• 2015

Recently, the government is promoting the new renewable energy spread and expansion policy. To this end, the investment and the research is ongoing on the core of the ESS (Energy Storage System) for the Smart Grid that is being spread around the industrialized countries. US and European countries have also conducted a variety of ESS related systems maintenance and improvement in order to induce the activation of the ESS industry. On the other hand, our country has no law and institutional foundation for the introduction of activation ESS, and there is no objective basis for the economic impact of the introduction of the ESS. Therefore, spread and activation of the ESS is not properly conducted. In this paper, the economics of the ESS based on the Korea electric pricing system for the spread and activation of the ESS effectively proposes a technique for analysis. To do this, define the ESS operating model, and propose the best economic analysis method economic analysis comparing each operating model.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.239-240
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• 2013

The increased demand for conventional energy sources, and international oil price rises are driving societies toward research and development of renewable energy. A large number of their installations and penetrations will bring an instability distribution power system. Also, load concentration problem at specific time can cause the shortage of power reserve margin. To deal with these problems, the development of energy storage systems (ESS) is required. This paper proposes the 1MW grid-connected ESS with Li-ion battery and power conditioning system (PCS). The performances of the 1MW grid-connected ESS are evaluated and verified with the PSCAD/EMTDC based simulation test.