• 한국산업융합학회 논문집
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• 제21권6호
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• pp.329-335
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• 2018

In an electric vehicle and Energy Storage System(ESS), a large number of batteries are connected in series or parallel to obtain high voltage and current. The battery management system(BMS) is needed because battery has a characteristic that explode in overcharging and overcurrent situations due to the nature of the battery material and the battery life is dramatically reduced when the battery is overdischarged below the specified voltage. In this paper, we proposed a system that can manage a large amount of batteries through the communication of master-slave type with multiple microcontroller. We confirmed the stable operation of the proposed system through the balancing-charging and storage mode experiments.

• KEPCO Journal on Electric Power and Energy
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• 제2권1호
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• pp.115-119
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• 2016

For many past years, research in the operation of stand-alone Microgrid, which provides electric power generated from renewable energy sources and energy storage system instead of diesel generators, has been a major issue in order to prepare the exhaustion of fossil fuel and to protect environment, in island grids. Samso Island, known as the world's first stand-alone Microgrid in Denmark, is connected to the mainland grid through AC system, which has different technical conditions with Korea's isolated power system. Korea's first stand-alone Microgrid has been built in Ga-sa island, Chun-la-nam-do, based on Energy Management System (EMS) operation, and other islands are under construction to follow the next step. These stand-alone Microgrid's has large capacity of Battery Energy Storage System (BESS) and the proportion of the renewable energy sources are large, which makes it necessary to use a Microgrid-Energy Management System (MG-EMS) to operate the grid effectively and economically. However, since the main subject of MG-EMS is different from EMS, specific characteristics and functions must be different as well. In this paper, the necessary characteristics and functions are explained for a general MG-EMS compared to a large power system EMS.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 추계학술대회 논문집 학회본부
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• pp.63-66
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• 1991

With the diversity of life patterns and the improvement of level in life which have been resulted from the economic development, people have showed the tendency to pursue the comfortable life as well as the home automation or intelligent house. Furthermore, the clean energy supply and management system have been introduced for the solution of environmental problem on earth and the effective utilization of energy. This study is to describe the battery energy storage device, which is one of the clean energy supply and management systems that are economically efficient in both sides of supply and demand. and able to solve the problem of energy crisis.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 전력전자학술대회 논문집
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• pp.242-243
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• 2013

This paper presents a voltage and frequency regulation of a Micro-grid using a Battery energy storage system (BESS) and super-capacitor (SPC). The control methods for the both BESS and SPC are proposed to improve the regulation performance and battery life span. The simulation results using the PSCAD/EMTDC are provided to show the effectiveness of the proposed control.

• KEPCO Journal on Electric Power and Energy
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• 제8권2호
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• pp.143-149
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• 2022

As ESS safety issues increase recently, there is a need to more precisely monitor the temperature of the ESS. In this paper, DTS technology for temperature monitoring of ESS batteries is introduced and the temperature measurement principle is explained. The temperature of the battery module is measured using the DTS system, and the thermal deviation between battery cells inside the battery module is analyzed. In order to analyze how thermal imbalance affects the charging and discharging performance of the battery, an accelerated degradation test was conducted. Cycle life characteristics analysis, battery surface temperature change, and AC impedance characteristics were conducted to analyze how the performance of battery cells differs according to temperature conditions.

• 전력전자학회논문지
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• 제19권5호
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• pp.422-430
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• 2014

This study proposes a small-signal model and control design for a two-stage DC-DC-AC converter to investigate its dynamic characteristics in relation to battery energy storage system. When the circuit analysis of the two-stage DC-DC-AC converter is attempted simultaneously, the mathematical procedure of deriving the dynamic equation is complex and difficult. The main idea of modeling the two-stage DC-DC-AC converter states that this topology is separated into a bidirectional DC-DC converter and a single-phase inverter with an equivalent current source corresponding to that of the inverter or converter. The dynamic equations for the separated converter and inverter are then derived using the state-space averaging technique. The procedures of building the small-signal model of the two-stage DC-DC-AC converter are described in detail. Based on the derived small-signal model, the individual controllers are designed through a frequency-domain analysis. The simulation and experimental results verify the validity of the proposed modeling approach and controller design.

• 한국산학기술학회논문지
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• 제15권9호
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• pp.5893-5898
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• 2014

본 논문은 연료비를 최소화 할 수 있는 2차전지 전력저장장치(BESS: Battery Energy Storage System)와 풍력-디젤 복합발전시스템으로 구성되는 독립형 마이크로그리드을 모델링하는 방법과 그 운전제어 알고리즘을 제안하였다. 먼저, 부하변동 및 풍속변동에 따른 주파수와 전압을 일정하게 제어할 수 있는 양방향 DC/AC 컨버터의 BESS를 모델링하고, 디젤발전기는 공급전력의 부족 및 BESS의 충전시에만 가동하도록 하는 운전제어알고리즘을 제안한다. 그리고, 제안된 모델링 방법과 운전제어알고리즘을 독립형 마이크로그리드에 적용한 결과, 풍속 및 부하변화에 대하여 주파수와 전압변동이 적정범위내로 유지할 수 있음을 증명할 수 있었다.

• 한국기계가공학회지
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• 제19권5호
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• pp.105-110
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• 2020

The global battery market is rapidly growing due to the development of vehicles(EV) and wireless electronic products. In particular logistics robots, which hielp to produce EVs, have attracted much interest in research in Korea Because logistics sites and factories operate continuously for 24 hours, the technology that can dramatically increase the operation time of the logistics equipment is rapidly developing, and various high-level technologies are required for the batteries used in. for example, logistics robots. These required technologies include those that enable rapid battery charging as well wireless charging to charge batteries while moving. The development of these technologies, however, result in increasing explosions and topical accidents involving rapid charging batteries These accidents due to the thermal shock caused by the heat generated during the charging of the battery cell. In this study, a performance evaluation of a heat dissipation design using infrared thermal imaging was performed on an energy storage systrm(Ess) applied with an internal heat conduction cooling method using a heating plate.

• 전기학회논문지
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• 제64권4호
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• pp.616-622
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• 2015

A microgrid which is composed of distributed generation systems, energy storage systems and loads is operated in the grid-connected mode and in the islanded mode. Especially, in the islanded mode, a microgrid should maintain frequency in the allowed range. The frequency is decided by a balance between power supply and power demand. In general, the frequency is controlled by using battery energy storage systems (BESSs) in the microgrid. Especially, droop control is applied to controlling BESSs in the microgrid. Meanwhile, over-charging and deep-discharging of BESS in operation and control cause life-shortening of batteries. In this paper, a fuzzy droop control is proposed to change droop gains adaptively by considering state of charge (SOC) of BESSs to improve the life cycle of the battery. The proposed fuzzy droop control adjusts droop gains based on SOC of BESSs in real time. In other to show the performance of the proposed fuzzy droop control, simulation based on Matlab/Simulink is performed. In addition, comparison of the convention droop control and the proposed fuzzy droop control is also performed.

• 전기학회논문지
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• 제61권12호
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• pp.1848-1856
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• 2012

This paper proposes a new grid-tied power conditioning system for battery energy storage, which is composed of a 2-stage DC-DC converter and a PWM inverter. The 2-stage DC-DC converter is composed of an LLC resonant converter connected in cascade with a 2-quadrant hybrid-switching chopper. The LLC resonant converter operates in constant duty ratio, while the 2-quadrant hybrid-switching chopper operates in variable duty ratio for voltage regulation. The operation of proposed system was verified through theoretical analysis and computer simulations. Based on computer simulations, a hardware prototype was built and tested to confirm the technical feasibility of proposed system. The proposed system could have relatively higher efficiency and smaller size than the existing system.