• 한국화재소방학회논문지
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• 제31권5호
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• pp.70-77
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• 2017

삶의 질이 높아짐에 따라 에어컨의 사용이 증가하고 있다. 따라서 에어컨 사용에 따른 화재 또한 빈번하게 발생하고 있어, 이에 따른 예방대책이 요구된다. 지난 2016년 전국 화재발생은 43,413건 이며, 이중 전기로 인한 화재가 8,655건으로 약 20%를 차지하였다. 전기화재 중 에어컨은 134건으로 약 1.5%를 차지하였고, 불완전접촉, 합선, 트래킹과 같은 다양한 원인으로 발생하는 것으로 나타났다. 본 연구는 에어컨 설치과정에서 실외기에 연결된 전원코드를 임으로 연결하는 접속부위에서 발화한 사례에 대하여 연구하고 그 원인에 따른 예방대책을 제시하여 전기화재로부터 인명과 재산피해를 다소나마 줄이고자 한다.

• Structural Engineering and Mechanics
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• 제84권2호
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• pp.155-165
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• 2022

The use of electricity and communication between electronic devices is increasing daily, which makes the stability of electrical power supply vital. Since the 1990s, large earthquakes have occurred frequently causing considerable direct damage to electrical power facilities as well as secondary damage, such as difficulty in restoring functions due to the interruption of electric power supply. Therefore, it is very important to establish measures to protect electrical power facilities, such as transformers and switchboards, from earthquakes. In this study, a 154 kV transformer whose service life had expired was installed on the base fabricated by simulating the field conditions and conducting the shaking table tests. The dynamic characteristics and seismic behavior of the 154 kV transformer were analyzed through the resonance frequency search test and seismic simulation test that considers the front, rear, left, and right directions. Since the purpose of this study is to analyze the acceleration amplification in the bushing due to the acceleration amplification, the experimental results were analyzed focusing on the acceleration response and the converted acceleration amplification ratio rather than the failure due to the displacement response of the transformer. The seismic force amplification at the transformer bushing was evaluated by simulating the characteristics of electrical power facilities in South Korea, and compared with the IEC TS 61463 acceleration amplification factor. Finally, the amplification factor at zero period acceleration (ZPA) modified for each return period was summarized. The results of this study can be used as data to define the amplification factor at ZPA of the transformer bushing, simulating the characteristics of electrical power facilities in Korea.

• 대한전기학회논문지:전력기술부문A
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• 제52권5호
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• pp.287-293
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• 2003

The deregulation and structural reform of power markets have started from the early 90s, which has brought about new studies on the new environment. Regardless the market structure, however, power systems need to be operated and planned in a stable and reliable manner. Therefore, decisions on proper amount of operating reserves and their reliable operations are very important. Up to now, the decision processes of operating reserves depend mainly on experiences of operators in Korea. When Korean power market comes under private management, operating reserves would influence power rate as well as power Quality, Therefore, it is time to prepare reasonable operating reserve standards in a systematic way for the new environment. This study suggests the proper operating reserve standards considering rules of the power market in Korea. To verify the adequacy of the proposed standards, stability and frequency characteristics of the Korean power system are analyzed as well.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.286-289
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• 2008

Wind turbine industry is booming and spending a lot on research for improving the performance of its present machines and increasing their capacity. Wind turbine requires service life of about 20 years and each components of wind turbine requires high durability, because installation and maintenance costs are more expensive than generated electricity by wind-turbine. So the design of wind turbine must be verified in various condition before production step. For this work, high reliability model for analysis is required. Drivetrain model is modeled by multibody dynamic modeling method. The model constituted with rotor blades, hub, main shaft, gear box, high speed shaft and generator. Natural frequency and torsional stiffness of drivetrain are calculated and analyzed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 추계학술대회 논문집 전력기술부문
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• pp.322-324
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• 2007

In this paper conceptual design methodologies of electric safety systems are proposed by micro and macro views. As a pre-study electric accidents of Korea were analyzed microscopically, which could be categorized into 11 types by the occurrence frequency. These types are caused by common problems, which are educations, live works, dealing by the public, and grounding systems. And the korean electric safety system is analyzed macroscopically according to stages of the system comparing with that of developed countries.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.741-745
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• 2007

Supplying power to microsystems that have no physical connection to the outside is difficult, and using batteries is not always appropriate. This paper discusses how to generate electricity from mechanical energy when vibrated in a cantilever beam. A model for the system predicts that the output power of the system is maximized when the mechanical damping in the system is minimized. Furthermore, to cover a wide frequency range and to be useful in a number of applications, a system of beams with different resonant frequencies has been designed and optimized. This information makes it possible to determine what design alternatives are feasible for the creation of a micro power supply for any specific application of MEMS.

• 한국소음진동공학회논문집
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• 제19권7호
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• pp.736-745
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• 2009

Fuel cells convert a fuel together with oxygen in a highly efficient electrochemical reaction to electricity and water. Since the electrochemical reaction in the fuel cell stack dose not generate any noise, Fuel cell systems are expected to operated much quieter than combustion engines. However, the tonal noise and the broad band noise caused by a centrifugal compressor and an electric motor cause which is required to feed the ambient air to the cathode of the fuel cell stack with high pressure. In this study, the multi-camber perforated muffler is used to reduce noise. We propose optimized muffler model using an axiomatic design method that optimizes the parameters of perforated muffler while keeping the volume of muffler minimized.

• 조명전기설비학회논문지
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• 제26권12호
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• pp.80-86
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• 2012

The high-voltage pulse generator is consist of transformers of fundamental wave and harmonic waves, and shunt capacitances. The pulse has the fundamental wave and the harmonic waves that have been increased as a series circuit by the transformers to make high voltage pulse. This paper shows the high-voltage pulse generator simulation using a circuit program with experiment data. In the equivalent circuit, magnetized inductances and loss resistances which affect output voltage, have been obtained. The output capacitor circuits have characteristics of band pass. The output voltages of the pulse width 50% and 25%(PWM) were obtained. The output of the high-voltage pulse generator is 2.5kHz, 1.8kV.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2018년도 춘계학술대회
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• pp.232-234
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• 2018

본 논문에서는 RFID 태그와 리더로 구성되는 비접촉식 RFID 스마트 태그 시스템을 개발하였다.. 이시스템은 13.56MHz의 저주파수 대역으로 디자인하였다. 개발된 RFID 스마트 태그 보드는 AVR을 이용하여 디자인되었으며 시뮬레이션을 통하여 응답속도가 개선되는 결과를 얻었다. 또한 RFID 태그에 대한 회로 디자인, 시뮬레이션, 실험 결과를 설명하였다.

• International Journal of Control, Automation, and Systems
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• 제3권spc2호
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• pp.363-375
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• 2005

The paper describes some of the challenges that face the control of nonlinear interconnected power systems. The challenges include the selection of appropriate control and information structures that could range from a completely decentralized to a fully centralized structure. Once a structure is proven to be feasible, the effectiveness of control signals needs to be assessed. Analytical tools are derived for this purpose in the first part of the paper, and they are illustrated with a case study that involves the design of a damping decentralized controller using a Thyristor Controlled Series Compensation device. The second part of the paper deals with the load following and tracking problem through automatic generation control for a system that has been re-structured or deregulated. This problem can be solved using a completely decentralized scheme. It is solved here using fuzzy rules and with an emphasis on compliance with NERC's standards and reduction of wear and tear of the equipment. It is illustrated with a test system that has three interconnected control areas. Finally, comments on the economics of control and the author's vision are presented.