• Journal of IKEEE
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• v.23 no.1
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• pp.188-192
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• 2019

As the contribution of the Energy Storage System (ESS) on the power system operations has increased, it is required to secure the reliability on the capacity of ESS and this needs to consider the outage rate in calculating the available capacity of ESS. However, the existing method of calculating the outage rate does not consider the configuration of ESS and this does not accurately calculate the available capacity of ESS. For this, this paper analyzes the structural characteristics of ESS in Korean power system and proposes a method to calculate the outage rate of ESS. Through the study cases adopting the Korea Electric Power Corporation (KEPCO) ESS for providing the frequency response service, the effectiveness of the proposed method verified.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.6
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• pp.979-986
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• 2016

At present, electric power industry around the world are being gradually changed to a new paradigm, such as electrical energy storage system, the wireless power transmission. Demand for ESS, the core technology of the new paradigm, has been growing worldwide. However, it is essential to estimate the optimal capacity of ESS facilities for frequency regulation because the benefit would be saturated in accordance with the investment moment and the increase of total invested capacity of ESS facilities. Hence, in this paper, the annual optimal mathematical investment model is proposed to estimate the optimal capacity and to establish investment plan of ESS facility for frequency regulation. The optimal mathematical investment model is newly established for each season, because the construction period is short and the operation effect for the load by seasons is different unlike previous the mathematical investment model. Additionally, the marginal operating cost is found by new mathematical operation model considering no-load cost and start-up cost as step functions improving the previous mathematical operation model. ESS optimal capacity is established by use value in use iterative methods. In this case, ESS facilities cost is used in terms of the value of the beginning of the year.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.9
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• pp.1199-1205
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• 2014

A power system configuration has been increasingly advanced with a number of generating units. In particular, renewable energy resources are widely introduced due to the environmental issues. When applying the renewable energy sources with the ESS (Energy Storage System), the ESS is the role of a potential generating resource in the power system while mitigating the output volatility of renewable energy resources. Thus, for applications of the ESS, the surrounding environment of it should be considered, which means that capacity and energy of the ESS can be affected. Moreover, operation strategy of the ESS should be proposed according to the installation purpose as well as the surrounding environment. In the paper, operation strategy of the ESS is proposed considering load demand and the output of renewable energy resources on a hourly basis. Then, the cost of electrical energy is minimized based on the economic model that consists of capital cost, operation cost, fuel cost, and grid cost for a year. It is sure that peak-shaving effects can be achieved while satisfying the minimum cost of electrical energy.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.59-61
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• 2021

The electric propulsion development is underway to minimize pollutants and greenhous gas emissions during the operation of ships / offshore installation vessels. The importance of the use and efficient management of batteries, which is an ESS system in ships / offshore installation vessels, is increasing. Generally, in ESS where battery is applied, cell balancing and life span are monitored in real time by BMS. Ships / offshore installation vessel are equipped with several ESS rooms, and ESS rooms with ESS systems of the same specification are being constructed due to the recent demand for electric propulsion development. In this paper, we propose an algorithm to additionally predict and diagnose battery pack and cell balancing failures by comparing BMS data for each rooms. The proposed algorithm compares the BMS data of each ESS Room according to the environmental change of the ship / offshore installation vessels, measures accurate status information, and reliably monitors it to prevent accidents in advance.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.423-424
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• 2016

Recently, the mass production of Energy storage system (ESS) is actively perform around world. Energy storage system is a technique that stores power to energy storage device to supply energy into grid and load at peak-load. Therefore, the efficient energy management is available by using ESS system. The life of Lithium-ion battery is varied corresponding to the power usage, especially selected depth of discharge (DOD). The lifetime of battery is the one of the most issue of the ESS system because of its stability and reliability. Therefore, lifetime management of battery and power converter of ESS module is required. In this paper, the battery lifetime management method estimating residual power and lifetime of lithium ion battery of ESS system is proposed. Also, total avenue prediction of ESS system is simulated considering the total lifetime of battery.

• Annual Conference of KIPS
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• 2014.04a
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• pp.135-137
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• 2014

최근 공공건물, 중대형 건물 등에서 전력 피크 시간대에 또는 안정적인 전력공급을 위해 사용할 에너지를 저장하는 방법으로 ESS 를 채택하고 있다. 그러나 대부분의 ESS 의 상태를 모니터링하기 위해서는 별도의 PC 에 소프트웨어를 설치하거나, EMS(Energy Management System)와 같은 별도의 솔루션의 한 기능으로 확인할 수 있다. 이럴 경우, 소프트웨어가 설치되어 있지 않은 현장에서 확인이 어렵고, 자연방전이 일어난 경우 과방전의 가능성도 배제할 수 없다. 따라서 ESS 의 랙 내부에 LCD 화면을 탑재하여 ESS 독립적으로도 상태를 확인할 수 있도록 모니터링 시스템을 개발하였다. 본 연구의 ESS 모니터링 시스템은 ESS 의 안전성올 높이고, 보다 직관적으로 ESS 의 상태를 확인할 수 있도록 구현 하였다.

• The Transactions of the Korean Institute of Power Electronics
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• v.26 no.5
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• pp.334-341
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• 2021

Operation modes and control strategies for single-phase mobility charging station utilizing photovoltaic (PV) generation and energy storage systems (ESS) are proposed. This approach generates electric power from PV to transmit the mobility, ESS, and then transfer it to the grid when surplus electric power is generated during daytime. However, the PV power cannot be generated during night-time, and ESS and the mobility system can be charged using grid power. The power balance control based on power fluctuations and the resonant current control that can compensate harmonic components have been added to increase the stability of the system. The MATLAB/Simulink simulation was carried out to verify the proposed control method, and the 2-kW single-phase grid-tied PV-ESS smart mobility charger was built and tested.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.11
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• pp.1554-1560
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• 2017

Prepare a lose of 765kV transmission route in power system operation condition, there are some Special Protection Scheme(SPS)s in Korean power system. These SPS can make some preselected generators are tripped to avoid generator overspeed. Because of many of the new large power plants are installed to existing power generation sites due to the siting problem, the number of generator tripped by SPS should be increased. But that can be a cause of system frequency change under the Under Frequency Relay(UFR) 1st pickup level 59.0Hz. Therefore generation constraint should be considered until new transmission lines are installed. In this paper, we propose the ESS application for generation constraint mitigation by frequency damping control of ESS. To analysis an effect of ESS application, we use PSS/E dynamic simulation tool, CBEST model and controller model. The proposed ESS application is applied to the empirical Korean power system.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.65
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• pp.95-116
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• 2015

So far several attempts have been made to digitalizing sea transport documents. Three notable examples are SeaDocs, Bolero, e-B/L Korea and Ess-Databridge. Ess-Databridge was established in 2003, with the aim of promoting the use of electronic alternative to shipping documents. The ESS-Databridge system was piloted from 2005 and went live in January 2010. The ESS-Databridge operates under a private legal outline, the Databridge Services and Users Agreement (DSUA). In the Ess-Databridge system, only the user who is in control of the original bill of lading will be able to indorse it on to another user. Once the indorsement is effected and unless the indorsee decide store turn the documents, the indorser loses control and retains access only to an electronic document marked 'copy' for its records. A feature that appears to have been crucial to the success of the CargoDocs service is that visually, e-B/Ls produced using ESS-Databridge appear identical to the paper documents. The ESS-Databridge may be even more successful if the legislators take certain steps that will increase uniformity and certainty in electronic transport documentation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.8
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• pp.1009-1018
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• 2018

As the generation of renewable energy increases rapidly, the stability of the grid due to its intermittency becomes a problem. The most appropriate way to solve this problem is to combine and operate the renewable generators with the ESS(Energy Storage System). However, since the revenues of operating the ESS are less than the investment cost, many countries are implementing various incentive policies for encouraging investment of the ESS. In this paper we estimated optimal capacity of the ESS to maximize profits of renewable energy generation businesses under the incentive policy of Korea and analyzed the impact of the incentive policy on the future electric power system of Jeju island. The simulation results show that the incentive policy has significantly improved the profitability of the renewable energy businesses generation business. But the volatility of the net demand has increased as the energy stored in the ESS is discharged intensively at the time of the incentive application.