• Bulletin of the Korean Space Science Society
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• 2003.10a
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• pp.91-91
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• 2003

위성을 발사하기 전까지는 지상에서 EGSE(Electrical Ground Support Equipment)를 이용하여 충분한 시스템 단위의 위성체 기능 시험을 수행한다. KOMPSAT-2(Korea Multi-Purpose Satellite - 2)와 같은 소형 위성의 서브시스템 각각이 요구사항에서 제시하는 규격을 만족하는지 여부를 점검하는 단계에서 전력계 관련 서브시스템의 기능 시험도 EPS(Electrical Power Subsystem) Test Plan에 의해 순차적으로 수행한다. KOMPSAT-2 ETB(Engineering Test Bed)에서의 전력계 시험은 먼저 Test Fuse Modules Check를 수행하였다. 퓨즈 모듈은 PCU(Power Control Unit) 상에 설치되어 있는 장치로써 퓨즈 모듈의 입력과 출력 사이에 도통성 및 다른 출력과의 절연성을 검증한다. 다음으로 EGSE 중 PMTS(Power Monitor Test Set)와 PCU와의 직렬 인터페이스를 점검하는 PCU Interface Check를 수행하였다 시험절차서에 따라 PCU가 가지는 릴레이 스위치에 대하여 명령어를 보내어 릴레이의 동작 상태 및 출력 전압 등을 점검한다. 다음 단계에서는 DC Integration을 수행하여 ETB 하니스 중 전원 관련 라인을 점검하였다 PCU는 모든 위성체 하드웨어에 전력을 공급하는 장비로써 과전력으로부터 하드웨어를 보호하기 위하여 하니스를 연결하기 전에 우선적으로 시험한다. 다음으로는 ECU(EPS Control Unit)가 각각에 해당하는 하드웨어에 명령어를 보내어 전력계 전체적인 동작 상태 검증하는 EPS Hardware Command & Telemetry Checkout을 수행하였다. ECU는 전력계의 모든 하드웨어를 제어하고 그 상태를 모니터링하는 기능을 한다. PCU와의 인터페이스를 통하여 전력의 제어 및 분배에 관련되는 특성을 제어 및 모니터하며 DDC(Deploy Device Controller)는 ECU로부터 명령어를 받아서 arm 및 safe 상태에 대한 텔리 메트리 데이터를 제공한다 그리고, SAR(Solar Array Regulator)는 ECU로부터 Bypass Relay 및 ARM Relay에 관한 명령어를 받아 수행되며 그에 따른 텔리 메트리 데이터를 제공한다. 마지막으로 EPS 소프트웨어를 검증하는 EPS Software Verification을 수행하였다 전력계 소프트웨어의 설계의 검증 부분은 현재 설계 제작된 전력계 .소프트웨어의 동작 특성 이 위성 의 전체 운용개념과 연계하여 전력계 소프트웨어가 전력계 및 위성체의 요구조건을 만족시키는지를 확인하는데 있다. 전력계 운용 소프트웨어는 배터리의 충ㆍ방전을 효율적으로 관리해 3년의 임무 기간동안 위성체에 전력을 공급할 수 있도록 설계되어 있다

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.871-874
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• 2010

Needs for Smart Grid development are increasing all over the world as a solution to its problem according to depletion of energy resources, climatic and environmental rapidly change and growing demand for electrical power. Especially decentralized power is attracting world's attention. In this mood a new era for a unit scale of decentralized power environment is on its way in building. However there is a problem to have to be solved in the uniformity of power quality because the amount of power generated from renewable energy resources such as wind power and solar light is very sensitive to climate fluctuation. And thus this paper tries to suggest an energy management method on basis of real time monitoring for meteorological data. In the current situation of lacking in USN-based killer application in Smart Grid field, this paper proposes the USN-based DER management system which collects the meteorological data and control power system througout utilizing wireless sensor network technique this business. This communication technique is regarded to be efficient in aspects of installation cost and tits maintenance cost. The proposed EMS model embodies the method for predicting the power generation by monitoring and analyzing the climatic data and controling the efficient power distribution between the renewable energy and the existing power. The ultimate goal of this paper is to provide the technological basis for achieving zero-energy house.

• KIISE Transactions on Computing Practices
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• v.23 no.12
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• pp.691-697
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• 2017

Volcanic ash has been predicted to be the main source of damage caused by a potential volcanic disaster around Mount Baekdu and the regions of the Korean peninsula. Computer simulations to predict the diffusion of volcanic ash should be performed according to prevalent meteorological situations within a predetermined time. Therefore, a workflow using pipelining is proposed to parallelize the software used for this computation. Due to the nature of volcanic calamities, the simulations need to be carried out for various plausible conditions given that the parameters cannot be precisely determined during the simulations, even at the time of a volcanic eruption. Among the given conditions, computations need to be first performed for the condition with the highest probability so that a response to the volcanic disaster can be provided using these results. Further action can then be performed later based on subsequent results. The computations need to be performed using a volcanic disaster damage prediction system on a computing server with limited computing performance. Hence, an optimal distribution of the computing resources is required. We propose a method through which specific data can be provided first to the proposed pipeline-based workflow.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.4
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• pp.360-364
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• 2012

AC to DC converter that consists of relatively simple diode rectifier devices has been widely used in the field of the electric propulsion system. Also, since this rectifier includes large harmonics in the input current, a variety of researches have been developed to reduce the harmonics. The proposed method of this paper is to reduce the harmonics included in the input current of rectifiers and propulsion motor by injecting the output current of diode rectifier into the input of them. In addition, the proposed method ensures electrical safety through the respective isolation of the injection current, the source, and the loads using the Wye-Delta insulating transformer applied in current injection device that is installed in the input circuit of rectifiers and propulsion motor. The proposed method is simulated by applying to the electric propulsion ship that is currently operating. We confirm the validity of the proposed method compared with conventional power conversion system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.8
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• pp.3603-3609
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• 2011

In this paper, we proposes new load-sharing algorism for equal current division using CAN communication. Proposed algorithm is different from conventional analog method, it performed strong Load-sharing using bi-direction high speed communication. Each modules constitution on independence controller (voltage controller, electric current controller). In parallel system prototype, each module have controller and performed load-sharing according to master module integral value. Also additional controller use for getting each module situations that fault situation of module and fault locate of module. we implemented high efficient load-sharing and redundancy. In this paper, we verify the validity of proposed algorithm using PSIM program and prototype.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.4
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• pp.298-308
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• 2017

This paper presents a Interleaved Buck Converter(IBC) system with Random PWM to reduce electromagnetic noise by harmonics. Swithced mode power supply generally controlled by high switching frequency have a electromagnetic interference(EMI) issue due to the high-voltage/high-current switching to regulate the voltage in buck converter. To solve the problem. we present a novel IBC system with PRBS. IBC system has two active switches with 180 phase difference that controll the cicuit with two PWM signal. IBC system may be disadventageous for the cost due to the addtion of one set of switch, but it has adventages of power distribution, current ripple cancellation, fast transient response, and passive component size reduction. To verify the validity of study, simulation program has been bulit using PSIM and the experimental results of IBC system using RPWM was compared with the conventinal PWM and randomized PWM.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.1
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• pp.74-82
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• 2019

The revolution of industry 4.0 is enabling us to build an intelligent connection society called smart cities. The use of renewable energy in particular solar energy is extremely important for modern society due to the growing power demand in smart cities, but its difficult to monitor and manage in each buildings since need to be deploy low energy sensors and information need to be transfer via wireless sensor network (WSN). The Internet of Things (IoT) / low-power wide-area (LPWA) is an emerging WSN technology, to collect and monitor data about environmental and physical electrical / electronics devices conditions in real time. However, providing power to IoT sensor end devices and other public electrical loads such as street lights, etc is an important challenging role because the sensor are usually battery powered and have a limited life time. In this paper, we proposes an efficient solar energy-based power management scheme for smart city based on IoT technology using LoRa wide-area network (LoRaWAN). This approach facilitates to maintain and prevent errors of solar panel based energy systems. The proposed solution maximizing output the power generated from solar panels system to distribute the power to the load and the grid. In this paper, we proved the efficiency of the proposed system with Simulink based system modeling and real-time emulation.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.366-375
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• 2022

The monitoring of electricity consumption using Internet of Things (IoT) technology is attracting attention as a technology to reduce operation costs of smart farms. In this study, we propose a method to apply a real-time electrical consumption monitoring system (the e-Gauge system) and utilization of the collected data real-time while a melon-producing smart farm is in operation. For this purpose, the electrical consumption data for the individual smart-farm facilities such as boilers, nutrient distribution systems, automatic controllers, circulation fans, boiler controllers, and other IoT-related utilities were collected during three months of melon cultivation period. By using the monitoring results, the electrical energy consumption pattern was analyzed as an example, and necessary considerations needed to optimally utilize the measurement data were suggested. This paper will be useful in lowering the technological implementation barriers for new researchers to build a electrical consumption monitoring system and reducing trial and errors in the usage of the generated data.