• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.10
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• pp.1508-1516
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• 2015

This paper proposes the optimal operation of ESS (Energy Storage System) in the substation of urban railway in an economical point of view. Since the load patterns of urban railway have different characteristics with the general power demand pattern, the characteristics motivate us to develop the optimal operation algorithm for ESS under Korean electricity billing system. We also introduce two different ESS operation strategies for peak load shaving and electricity consumption charge minimization respectively, and formulate each scheme. Historical data from Namgwangju substation are used for economical comparison of the strategies. The results show that the proposed algorithm is the most cost-effective ESS operation scheme among the strategies and reduces around 5 percent of electric charges compared to the charge without ESS operation.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.5
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• pp.207-217
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• 2018

Recently, the importance of energy demand management, particularly peak load control, has been increasing due to the policy changes of the Second Energy Basic Plan. Even though the installation of distributed generation systems such as Photovoltaic and energy storage systems (ESS) are encouraged, high initial installation costs make it difficult to expand their supply. In this study, the power consumption of a university building was measured in real time and the measured power consumption data was used to calculate the optimal installation capacity of the Photovoltaic and ESS, respectively. In order to calculate the optimal capacity, it is necessary to analyze the operation methods of the Photovoltaic and ESS while considering the KEPCO electricity billing system, power consumption patterns of the building, installation costs of the Photovoltaic and ESS, estimated savings on electric charges, and life time. In this study, the power consumption of the university building with a daily power consumption of approximately 200kWh and a peak power of approximately 20kW was measured per minute. An economic analysis conducted using these measured data showed that the optimal capacity was approximately 30kW for Photovoltaic and approximately 7kWh for ESS.

• Journal of Korean Society for Quality Management
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• v.49 no.2
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• pp.161-170
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• 2021

Purpose: The purpose of this study was to evaluate the economic value of installing public Energy storage system (ESS) facilities using a logit regression analysis and Contingent Valuation Method (CVM). We focused mainly on the environmental benefits of ESS and analyzed how the users' attitude toward environmental protection and knowledge of renewable energy affect their Willingness to pay (WTP) Methods: A single-bounded dichotomous choice (SBDC) survey was used to collect the data. We asked participants whether they are willing to pay a randomly presented cost (KRW 100, 500, 1000, 1500, 2000, 2500, 5000, 10000) along with their attitude to toward environmental protection, knowledge of renewable energy, and perceived cost of electric bill. 417 valid samples were collected and used for the analysis. Results: The results of the logit regression show that the initial bid, attitude toward environmental protection, knowledge of renewable energy, and perceived cost of electric bill significantly affect the user's WTP of public ESS facilities. The CVM results show that users are willing to pay KRW 5,049.1/month to install ESS facilities. Conclusion: : According to results, we conclude that the users agree with the need to install ESSs and that environmental benefits of ESSs are important factors for ESS adoption. Therefore, policy makers need to emphasize environmental aspects to install the ESS facilities.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.65 no.4
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• pp.235-241
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• 2016

Grid-connected, large-capacity energy storage systems (ESS) can be used for peak load supply, frequency regulation, and renewable energy output smoothing. In order to confirm the capability of battery ESS to provide such services, 4MW/ 8MWh battery ESS demonstration facility was built in the Jocheon substation on Jeju Island. The frequency regulation technology developed for the Jocheon demonstration facility then became the basis for the 28MW and 24MW frequency regulation ESS facilities installed in 2014 at the Seo-Anseong and Shin-Yongin substations, respectively. The operation control systems at these two facilities were continuously improved, and their successful commercialization led to the construction of additional ESS facilities all over Korea in 2015. In seven (7) locations nationwide (e.g., Shin-Gimje and Shin-Gyeryeong), a total of 184 MW of ESS had been commercialized in 2016. The trial run for the new ESS facilities had been completed between April and May in 2016. In this paper, results of the trial run from each of the ESS facilities are presented. The results obtained from the Seo-Anseong and Shin-Yongin substations during a transient event by a nuclear power plant trip are also presented in this paper. The results show that the frequency regulation battery ESS facilities were able to quickly respond to the transient event and trial run of ESS is necessary before it is commercialized.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.8
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• pp.1024-1030
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• 2018

Recently, the large scaled energy storage system(ESS) which has various functions such as peak saving, demand management, output stabilization of renewable energy and frequency regulation(FR) is being energetically installed and operated. Especially, as the use case of frequency regulation ESS, the KEPCO has demonstrated the total of 376[MW] ESS since 2014. However, there are no operational experiences and international technical standards on frequency regulation application in ESS. Therefore, this paper propose the evaluation algorithm for power system performance of ESS by considering the frequency characteristics between governor of existing generator and frequency regulation ESS, in order to verify the power system performance of ESS. And also, this paper propose an evaluation modeling for small scaled power system including the existing generator, frequency control ESS and customer loads based on the PSCAD/EMTDC S/W. From the simulation results in 360[MW] model power system, it is confirmed that frequency regulation ESS has better performances than conventional generators.

• Journal of Electrical Engineering and Technology
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• v.12 no.2
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• pp.981-987
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• 2017

In this paper, we estimate the economic benefits of Energy Storage Systems (ESSs) for peak load shaving in an urban railway substation using the annual cost. The annual investment cost of ESSs is estimated using Net Present Value (NPV) and compared with the cost reduction of electricity by the ESS. The optimal capacities of the battery and Power Converting System (PCS) are determined for peak load shaving. The optimal capacity of the ESS and the peak load shaving is determined to maximize the profit by the ESS. The proposed method was applied to real load data in an urban railway substation, and the results show that electric power costs can be reduced. Other aspects of the ESS, such as the lifetime and unit price of the battery, are also investigated economically.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.461-462
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• 2016

본 논문은 100kW 급 비상발전용 ESS 상용화 개발을 제안한다. 비상발전기란 전력계통이 정지되었을 때 발전장치를 구동시켜 전력을 생산하는 자가발전설비를 말한다. 제안하는 시스템은 2Level 전압형 100kW 급 비상발전용 ESS 로써 정상 시 계통 전원과 동기 운전을 수행하는 계통 연계형 전력변환장치이다. 수배전 수용가에 설치되어 운영이 가능하며 일반적인 ESS PCS 기능인 주파수 조정 (Frequency Regulation), 출력 안정화, 첨두부하 저감 (Peak Shaving), 부하평준화 (Load Leveling), 수요반응 (Demand Response)에 추가하여, 자가발전 (Black Start), 무효전력제어 등의 기능을 적용 하였다. 제안된 100kW 급 비상발전기용 ESS PCS 는 시뮬레이션 및 프로토 타입을 이용하여 성능을 검증하였다.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.5
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• pp.587-592
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• 2005

The ESS(Energy Saving System) is designed to have functions of controlling. monitoring for cooling system. etc. ESS consists of the I/O module, CPU module and Display module I/O module detects various ESS data on local area and treats signals via I/O interface system. The interface system receives various status data and outputs control signals. ESS is tested with dummy signal to verify proposed functions and is shown good results. For future study ESS will be tested under real condition in the ship.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.6
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• pp.905-910
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• 2017

As the development of BESS(Battery Energy Storage System), the application of BESS in load frequency control is considered as effective method. So, KEPCO(Korea Electric Power Corporation) have installed about 236MW ESS for GF(Govner Free) function from 2014. In this paper, we implemented Simulink Model for KEPCO GF ESS and analyzed one year historical operation data generated by Simulink model and actually measured frequency data. The operation results were divided into action for maintaining SOC and frequency. In addition, we also analyzed cycle life of GF ESS using two ESS cycle life model. We concluded the ESS cycle life models are not appropriate, because Most of the SOC swing in operation results are below 10%.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.5
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• pp.86-93
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• 2015

Recently, ESS became efficient device to stabilize electric power supply system with the development SG related technology. In fact. there are some constraints to supply ESS, because of the high cost and required space, but rapid technology development for ESS will make it more useful soon. So, through this paper, we analyzed the benefit and demand effect when the battery is applied the building based on the measured energy consumption. After that, we got the conclusion that there is a volume limit in ESS application, in a benefit view point. And we realized that there is a demand violation, and the Cost-based BEMS is the best solution to enhance the effect of ESS application.