• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.2
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• pp.242-247
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• 2010

This paper introduces a real-time load flow program for Korean energy management system(EMS). This study is concentrated on the following aspects. First, we propose the model of the real-time database and power system equipment for the real-time load flow. These models are extracted from the needs of load flow functions and are designed to the application common information. Second, several techniques are applied for the efficient convergence and computational speed. The generation/load mismatch is redistributed using generator participation factors which are separated to the reference bus. For the voltage control, the jacobian matrix is composed with the basic Y matrix elements and the voltage control elements. Through the optimally ordering, jacobian row and column for a column is changed. However all jacobian matrix entries have same order with the Y matrix. The proposed program is tested using the Korea Electric Power Corporation(KEPCO) system. Through the test, we verified that the proposed program can be effectively used to accomplish the Korean EMS system.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.2
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• pp.277-282
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• 2020

The construction of medium-and large-sized microgrid systems by unit area, which is being promoted worldwide, is being developed and expanded in the form of efficient operation of electric grids and independent operation in preparation for power emergencies. Therefore, for the development of the domestic electricity industry, it is urgent to analyze the current status and technology of relevant international standardization, and to make international standardization of domestic standard (draft) on the matters that need to be enacted and newly established. Campus microgrid implements smart grid element technologies such as Integrated Energy Management System(EMS), Distributed Power(DG), Energy Storage System(ESS), Demand Response(DR), and Electric Vehicle(EV) in a university campus. As a system that reduces energy use and improves energy use efficiency and energy independence, standardization is established to secure interoperability and reliability of such systems.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.4
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• pp.609-613
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• 2016

A hybrid charging method with serial and parallel architecture has been developed to resolve the unbalanced charge problem among battery cells for Electric Vehicles. In this method, the major charging is performed with serial part and the balancing is carried out with the parallel part, where the serial part is big and heavy but the parallel part is smaller and lighter than serial part. A sensor array to detect the individual battery cell voltage, duty rate control incorporated IGBTs, and battery management system are employed as the core parts of the proposed system.

• Journal of Climate Change Research
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• v.7 no.3
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• pp.217-229
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• 2016

Increased evidences reveal that the global climate change adversely affect on the environment. Smart grid system is one of the ways to reduce greenhouse gas emissions in the electricity generation sector. Since 2013, Korea Electric Power Corporation (KEPCO) has installed smart grid station in KEPCO office buildings. The goal of this paper is two folds. One is to quantify the reduction in greenhouse gas emissions through smart grid stations installed in KEPCO office buildings as a part of pilot project. Among components of smart grid stations, this research focused on the photovoltaic power system (PV) and energy storage system (ESS). The other is to estimate the reduction in greenhouse gas emissions when PV is applied on individual houses. Results show that greenhouse gas emissions reduce 5.8~11.3% of the emissions generated through the electricity usage after PV is applied in KEPCO office buildings. The greenhouse gas emissions reduction from ESS is not apparent. When PV of 200~500 W is installed in individual houses, annual greenhouse gas emission reduction in 2016 is expected to be approximately $2.2{\sim}5.4million\;tCO_2-eq$, equivalent to 6~15% of greenhouse gas emissions through the electricity usage in the house hold sector. The saving of annual electricity cost in the individual house through PV of 200 W and 500 W is expected to be 47~179 thous and KRW and 123~451 thousand KRW, respectively. Results analyzed in this study show the environmental effect of the smart grid station. In addition, the results can be further used as guidance in implementing similar projects.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.7
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• pp.56-64
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• 2012

A smart grid is the next generation power grid which combines the existing power grid with information technology, so an energy efficient power grid can be provided. In this paper, in order to build an efficient smart grid an AMI system, which gears with the existing home network and provides an user friendly management function, is proposed. The proposed AMI system, which is based on an extended home network, consists of various functional units; smart meters, communication modules, home gateway, security modules, meter data management modules (MDMM), electric power application modules and so on. The proposed home network system, which can reduce electric power consumption and transmit data more effectively, is designed by using IEEE 802.15.4. The extended home gateway can exchange energy consumption information with the outside management system via web services. The proposed AMI system is designed to enable two-way communication between the home gateway and MDMM via the Internet. The AES(Advanced Encryption Standard) algorithm, which is a symmetric block cipher algorithm, is used to ensure secure information exchange. Even though the results in this study could be limited to our experimental environment, the result of the simulation test shows that the proposed system reduces electric power consumption by 4~42% on average compared to the case of using no control.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.180-181
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• 2011

에너지 절약 최적화를 위한 녹색 기술개발은 지속가능경제와 화석연료 사용에 의한 부작용을 최소화하기 위한 전세계적 화두로 대두되고 있다. 중소기업은 다양한 품목에서 자체적인 생산활동을 수행하며 대기업 제품에 사용되는 부품을 실질적으로 공급하고 전체 근로자의 85%이상을 고용하는 등 국가적인 부가가치 창출에 큰 역할을 수행하고 있으나, 인적자원과 관리 인프라의 부족과 부재로 인해 체계적인 에너지 관리를 통한 에너지 사용 절감을 위한 최적화 활동 수행에 한계점을 가지고 있다. 그러나, 향후 직접적인 에너지 절감을 통한 원가 경쟁력 향상은 물론 향후 탄소 거래제와 생산 공정과 결과물에 대한 정량적인 탄소배출량 관리제도의 법제화에 대비하여 이러한 제한상황에 대한 해결안 제시가 절실하게 요구되고 있다. 본 논문은 이러한 문제를 해결하기 위하여 서해안 산업단지를 대상으로 한국산업기술대학교 전력저감센터에서 개발중인 중소기업을 위한 energy saving management system (ESMS)에 대해 기술한다. ESMS는 개별 공장에서 소비되는 전체전력과 대표 부하에서의 소비전력의 전력품질과 현황을 모니터링하고 부하특성에 맞는 전력저감 메커니즘을 제공한다. 또한 자체적인 과거 소비전력 경향과 광역 공단의 전체 소비 데이터와의 비교 데이터를 통해 자체적인 전력 소비 현황 및 절감대책을 수립하도록 지원한다.

• The Transactions of the Korean Institute of Power Electronics
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• v.26 no.5
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• pp.357-363
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• 2021

Eco-friendly hybrid railroad propulsion system with fuel-cell and battery was suggested to reduce carbon dioxide gas and replace retired diesel railroads. Lithium-ion battery with high energy/power density and long lifetime is selected as the energy source at the battery side due to its excellent performance. However, the performance of lithium-ion batteries was affected by temperature, current rate, and operating condition. Temperature is known to be the most influential factor in changing battery parameters. In addition, appropriate thermal management is required to ensure the safe and effective operation of lithium-ion battery. Electro-thermal coupled model with varying parameter depends on temperature, and state-of-charge (SOC) is suggested to estimate battery temperature. The electric-thermal coupled model contains diffusion current using parameter identification by adaptive control algorithm when considering thermal diffusion effect. An experiment under forced convection was conducted using cylindrical cell and 18 parallel-connected battery module to demonstrate the method.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1319-1322
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• 2015

일반적으로 이차전지를 이용한 에너지 저장 시스템(ESS, Energy Storage System)과 전기 자동차(EV, Electric Vehicle)에 사용되는 전지(Battery)는 용량에 따라 직 병렬로 수십 개에서 수 만개의 배터리가 사용되기도 한다. 이러한 많은 배터리를 제어하고 관리하기 위해 필요한 것이 배터리 관리 시스템(BMS, Battery Management System)이다. 이러한 BMS는 ESS(Energy Storage System, 에너지저장시스템)의 핵심부품으로서, 관련업계에서는 새로운 기술 개발에 박차를 가하고 있다. 따라서 본 논문에서는 최근 개발되고 있는 AC 임피던스를 이용한 SOH 예측 기능을 검증할 수 있는 DSP(Digital Signal Processing) Platform 기반으로 Master-Slave 형태의 BMS를 개발하였으며, Master-Slave간에는 CAN 통신을 이용하여 제어성, 확장성을 용이하게 함으로써, 새로운 SOH 알고리즘 구현 및 성능 검증을 손 쉽게 구현할 수 있게 되었다.

• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.247-249
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• 2007

Urban dynamometer driving schedule(FTP-75 mode) plays very significant role on automotive emission test, due to reference point. The overall system energy efficiency of a HEV(Hybrid Electric Vehicle) is highly dependent on the energy management strategy employed. An energy source is the heart of a HEV. In order to applicable to a vehicle component, it must be need to real world test result. But, the present state of things have numerous problems. In this paper, be studied performed based on HEV simulation software in virtual world and chassis dynamometer test in real world and the result make a comparative. Toyota Prius vehicle was adapted as a modeling and real testing to evaluate the hybrid components and energy balancing management. The point at issue is voltage and current analysis for HEV battery SOC(State of Charge), and verification for energy.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.4
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• pp.284-292
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• 2022

Hydrogen is promising a candidate for energy supporting the carbon neutrality policy for greenhouse gas reduction, which is being promoted in several countries, including Korea. Although challenging efforts-such as lowering the costs of green hydrogen production and fuel cells-remain, hydrogen fuel cell electric vehicles (FCEVs) are expected to play a significant role in the energy transition from fossil fuels to renewable energy. In line with this objective, the hydrogen FCEV working group in the International Organization for Standardization (ISO) compiled and revised international standards related to hydrogen refueling stations as of 2019. A well-established hydrogen quality management system based on the standard documents will increase the reliability of hydrogen charging stations and accelerate the use of FCEVs. In this study, among the published ISO standards and other references, the main requirements for managing charging stations and developing related techniques were summarized and explained. To respond preemptively to the growing FCEV market, a continuous hydrogen quality monitoring method suitable for use at hydrogen charging stations was proposed.