• Proceedings of the KIEE Conference
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• 2008.04c
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• pp.143-145
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• 2008

본 논문에서는 산간벽지 또는 낙도와 같이 중앙계통으로부터 송 배전선을 이용한 전력공급이 어려운 약 계통(Weak grid)에 주로 사용되는 계통연계형 분산전원시스템의 설계 방법을 설명한다. Weak grid에서는 계통의 전압변동의 폭이 매우 크기 때문에 부하에 안정적으로 정전압을 공급할 수 있는 전압제어형 전압원인버터(VCVSI: Voltage-Controlled Voltage Source Inverter)를 주로 사용한다. 따라서 본 연구에서는 계통의 전압에 변동에 따른 각각의 시스템 파라미터 특성을 분석하고 이에 따른 최적의 시스템 용량의 선정방법을 제시한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.601-610
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• 2020

Recently, damage caused by drought is becoming worse and worse due to the global climate change. To overcome these problems, movable-weir to control the water level has been installed instead of a fixed-weir made from concrete. On the other hand, it is difficult to operate an existing moveable-weir because of the high cost of facility management and manpower consumption. In addition, because most moveable-weirs are installed in power systems, the operating cost and the cost of connection for power systems increase when they are located in remote areas. Therefore, this paper proposes an optimal design algorithm and the evaluation algorithm of the SOC (state of charge) of a lithium-ion battery to replace an existing power supply with eco-friendly movable-power with a power supply system using PV modules and lithium-ion batteries. In addition, this study modeled a 50kW power supply system of a movable-weir using PSCAD/EMTDC S/W. The simulation results confirmed that the proposed algorithm has stable operation characteristics in an independent operation mode and interconnection operation mode and that there is the possibility of commercialization with a benefits evaluation of the eco-friendly power supply system of a movable-weir.

• Journal of Energy Engineering
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• v.11 no.3
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• pp.216-223
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• 2002

Generation facilities of the power system are mainly classified into large-scale concentrated generation and small-scale dispersed generation, but generation planning of the Korea power system has been focusing on the large-scale generation so far. Recently, however, applications of dispersed generation sources including solar cell, fuel cell, wind power, etc. have been rapidly increasing and being strongly promoted, and such generation sources should be comprehensively considered in both planning and operating. Since it is not always possible that the dispersed generation alone meets all the load interconnected to it is especially when a fault occurs, interconnection into the existing utility is desirable and recommended. In relation to wind power generation systems interconnected at the low and extra high voltage levels, this paper performs the simulation and analysis of the system protection and suggests protection coordination plans on various faults which possibly occur.

• Proceedings of the KIPE Conference
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• 2016.11a
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• pp.192-193
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• 2016

본 논문은 계통 전원 정전 시 계통 전원을 대신하여 전력을 엘리베이터 구동 시스템에 공급함으로써 정전으로 기동이 정지된 엘리베이터 내부에 고립된 승객에 대한 비상구출 운전을 실시하는 자동 비상 구출 운전 시스템의 축전지 충전 회로에 관한 Simulink 및 PSpice 연동 해석 모델 개발을 실시한다.

• KIPE Magazine
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• v.19 no.5
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• pp.47-52
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• 2014

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.2
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• pp.215-222
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• 2023

Alternative marine power (AMP) is continuously used in ports and on docks because of regulations on global ship emission reduction. In Korea, the use of AMP is also mandatory under the Special Act on Port Air Quality Improvement, and efforts are under way in connection with various eco-friendly ships, such as electric-propulsion ships. In this study, AC load flow analysis was performed by modeling the situation in which onboard power is supplied through AMP. This analysis made it possible to study the electrical parameters and losses when power was supplied to the ship. In addition, through a transient stability analysis, the high-speed generation transfer limit value for uninterruptible conversion through onboard generators in the event of a system accident was derived. The results obtained when it was applied are presented

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.6
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• pp.135-140
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• 2021

In this paper is a study on system design to prevent accidents using accelerometers. A switching power FET was configured at the power supply stage, and DC-DC converter, a regulator, and an LDO were designed for the power supply. In order to solve the power problem at once, it was divided into two parts, and a 3-axis accelerometer was designed to extract motion information to safely prevent accidents. Microprocessor enables communication through I2C and UART communication ports, and enables debugging through J-LINK. As a result of measuring the acceleration sensor data, it was confirmed that the power is normally cut off to prevent accidents when motion at an angle of 30° or more is detected.

• Proceedings of the KIPE Conference
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• 2015.11a
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• pp.117-118
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• 2015

본 연구에서는 독립형 직류 배전망 구성에 이용될 수 있는 태양광 발전 시스템 및 ESS(Energy Storage System)를 이용한 하이브리드형 분산 전원 시스템의 구성 일례를 제시한다. 제안된 시스템의 전력회로는 태양광 발전 시스템용 PCS에는 직렬 공진 탱크를 가지는 절연형 풀브리지 방식, ESS용 PCS에는 비절연형 양방향 컨버터로 구성되었다. 태양광 PCS의 제어방식으로는 전류 제어기가 사용되었으며, ESS 용 PCS에는 비집중식 제어방식이 적용 되었다. 제안된 방식의 타당성을 검증하기 위해 100[kW]급 태양광 시스템, 100[kW]급 ESS를 기반으로 하이브리드 시스템을 구현하고 직류 계통 전압 제어 특성, 부하급변에 대한 전력분담 제어 실험결과를 제시하였다.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.184-187
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• 2007

본 논문은 DSP Controller를 적용한 연료전지시스템의 유량제어에 관한 논문이다. 그리고 이 연구에서 사용된 시스템은 1kW급 계통연계 연료전지 시스템이다. 이 연료전지 시스템이 안정적으로 전원을 공급할 수 있도록 시스템에서 요구하는 공기 유량을 정확히 공급하도록 제어하는 것이 본 연구의 목적이다. 이 목적을 이루기 위해 공기 공급 장치에 PID 제어기를 설계하여 적용하였다. PID 제어기의 Gain값은 지글러 니콜스 Tuning 방식으로 정하였다. 이 제어기를 적용하여 실험한 결과, 적용 전 상태와 비교하면 맥동이 30% 저감하였고, 정상상태 오차가 제거되어 온도 변화와 같은 외란과 상관없이 정확한 요구 공기 유량을 공급함을 확인할 수 있었다. 그리고 부하가 변동함에 따라 해당 요구 공기 유량이 바뀔 때 1초 내에 그 요구 공기 유량을 추종하여 스택이 안정적으로 운전될 수 있도록 하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.8
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• pp.1802-1809
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• 2009

Abstract The typical distribution systems have the power flow from distribution substations (sources) to customers (load) only as one direction. However, in the case where distributed generations (DG) such as PV system and wind power systems are connected to distribution systems, the DG output variations to distribution systems, so called reverse power flow, may cause the bi-directional power flow. So, the reverse power flow has severe impacts on typical power system, for example power quality problems, protection coordination problems, and so on. Especially, protection devices (sectionalizer) in primary feeder of distribution system interconnected with distributed generations may cause problems of malfunction, and then many customers could have problems like an interruption. So, this paper presents the bi-directional operation algorithm of protection devices to overcome the problems like mal-function. And, also this paper shows the effectiveness of proposed method by using both PSCAD/EMTDC software and test facility of protection devices to simulate the field distribution systems.