• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1955-1961
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• 2008

A lot of researches on a linear induction motor(LIM) have been advanced to realize a traction system with high efficiency and performance for railway transit for a long time. However, most of them are limited in design of a LIM part such as Primary and Secondary. At a LIM which is traveling, the change of an air-gap(It occurs by a construction tolerance of a secondary reaction plate) becomes the cause which decreases a smoother ride and the efficiency of railway transit system. Therefore, uniform air-gap operation of LIM is important issue to improve the system efficiency. However, the researches which control the air-gap length of the LIM with technical and high-cost problem have been not advanced a lot. Therefore, in this research, it is introduced an air-gap control system for performance test machine of a scale-downed LIM which is able to control the air-gap length of the LIM and monitor a variety of performance changes of the propulsion system, and conducted a research on feasibility of the system based on characteristic analysis.

• KIEAE Journal
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• 제7권5호
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• pp.59-64
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• 2007

Using air conditioner has been increased in home or office buildings in summer. Also various problems related to air conditioning such as disease induction happened by using air conditioner excessively and operating long. Active operation control is needed for occupant's health when air conditioner operates long. We should think ahead to acquire thermal comfort of occupants which represents psychological and physiological reaction for this operation. Research has been progressed to observe activity of autonomic nervous system by trying to quantitate change of thermal comfort. In this study, questions of the subject and change of body's autonomic nervous system were chosen to evaluate thermal comfort during operation of air conditioner for a long time. Electrocardiogram and questions of the subject which is the progress of changing TSV and CSV by occupants indoor were measured when room air conditioner is operated for a long time, and an air-conditioned adaptability of human body was evaluated by acquiring the change rate of autonomic nervous system through analyzing HRV. As a result of the evaluation, change rate of body's autonomic nervous system corresponded to votes of the subject's question generally, but was distinguished from analysis result of warm-cold sensation in a low temperature area.

• 공업화학
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• 제32권6호
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• pp.627-631
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• 2021

휘발성유기화합물을 제거하기 위한 기존 촉매 시스템의 문제를 해결하고자 유도가열 촉매 시스템에 대한 연구를 수행하였다. 본 연구에서는 3종류의 Ni계 상용촉매를 적용하였으며, 촉매 부피, 조성, 열처리 분위기, 코일 내 위치를 포함한 유도가열 반응 특성을 조사하였다. 촉매의 조성 및 부피는 유도가열 시스템에 의한 발열 및 톨루엔 산화 성능에 영향을 미쳤다. 특히 철이 첨가된 촉매는 99% 이상의 Ni로 구성된 촉매에 비해 높은 발열을 나타내었으나 낮은 톨루엔 산화 성능을 나타내었다. 또한 Ni계 촉매의 열처리에 있어 공기 분위기는 촉매의 성능을 급격히 저하시킨다. 유도가열 시스템에서 촉매는 코일 내 중심에 위치하는 것이 최적 조건으로 나타났다. 연구를 통해 도출한 최적의 조건에서 촉매를 7회 반복 실험하였으며, 유사한 성능을 확인하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 A
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• pp.40-42
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• 1999

In this paper, light-weight system of linear induction motor(LIM) for light railway train is presented, and is compared with former type of LIM. For the light-weight system without modification of motor size the material of primary core(silicon steel) is changed with iron-cobalt alloy and the material of primary winding(copper) is changed with aluminium. The characteristics of LIM are analyzed. Specially, the air gap magnetic flux density distribution due to end effect is showed with motor velocity, we will present papers continuously through designing and testing a trial product.

• 한국산학기술학회논문지
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• 제14권2호
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• pp.816-821
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• 2013

본 논문은 ARM Cortex-M4 마이크로컨트롤러를 사용하여 3상 유도전동기용의 저가형 벡터제어 인버터를 설계하는 방법을 제안한다. 이 MCU는 냉장고, 에어컨, 세탁기와 같은 가전제품을 제어하기 위하여 기존의 값비싼 DSP 소자를 대신할 수 있다. 본 논문에서는 전동기 제어에 필요한 Cortex-M4의 주요 기능들을 정리하고, 이를 사용하여 벡터제어 인버터를 설계하는 방법을 기술한다. 실험용 벡터제어 인버터를 설계 제작하여 200[W]의 3상 유도전동기에 적용하였고, 이를 사용한 실험 결과는 기존의 TMS320F28335 DSP와 유사한 수준의 제어 성능을 보였다.

• Journal of Electrical Engineering and Technology
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• 제13권1호
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• pp.60-67
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• 2018

The presence of induction motor loads in a power system may cause the phenomenon of delayed voltage recovery after the occurrence of a severe fault. A high proportion of induction motor loads in the power system can be a significant influence on the voltage stability of the system. This problem referred to as FIDVR(Fault Induced Delayed Voltage Recovery) is commonly caused by stall of small HVAC unit(Heating, Ventilation, and Air Conditioner) after transmission or distribution system failure. This delayed voltage recovery arises from the dynamic characteristics associated with the kinetic energy of the induction motor load. This paper proposes the UVLS (Under Voltage Load Shedding) control strategy for dealing with FIDVR. UVLS based schemes prevent voltage instability by shedding the load and can help avoid major economic losses due to wide-ranging cascading outages. This paper review recent topic about under voltage load shedding and compare decentralized load shedding scheme with conventional load shedding scheme. The load shedding strategy is applied to an actual system in order to verify the proposed FIDVR mitigation solution. Simulations demonstrate the effectiveness of the proposed method in resolving the problem of delayed voltage recovery in the Korean Power System.

• 한국산학기술학회논문지
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• 제16권7호
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• pp.4381-4387
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• 2015

선체의 외판은 복잡한 곡면 형상이며 대부분의 조선소에서는 이의 제작을 위해 가스 토치를 이용한 선상 가열 방법을 사용하고 있다. 가스 토치를 이용한 전통적인 선상 가열 방법은 입열량의 제어가 어려울 뿐만 아니라 고압의 가스 분출에 따른 소음과 대기 오염 등 열악한 작업 환경의 문제점을 안고 있다. 최근에는 입열량의 제어가 비교적 용이하고 친환경적인 고주파 유도 가열에 주목하여 이를 가열 열원으로 하는 강판의 성형 자동화 연구들이 진행되고 있다. 본 연구에서는 강판의 곡면 성형을 위한 유도 가열 시뮬레이션 방법을 개발하였으며 유도 가열 실험 결과와 비교하여 그 유효성을 검증하였다. 개발된 유도 가열 시뮬레이션 방법은 효율적인 유도 가열 코일 설계와 최적 성형 조건 산출 등 유도 가열을 이용한 선체 외판의 곡가공 자동화 시스템 개발에 유용한 해석적 툴로 활용될 수 있을 것으로 기대된다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2005년도 춘계학술대회논문집
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• pp.319-324
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• 2005

The interface between host processor and the ShortStack Micro Server may be a Serial Communication Interface(SCI). The LonWorks control module with a high performance is developed, which is composed of the 8 bit PIC Microprocessor for host processor and the smart neuron chip for the ShoretStack Micro Server. This intelligent control board is verified as proceeding the various function tests from experimental system with an boost pump and inverter driving systems. It is also confirmed that the developed control module provides stably 0-10VDC linear signal to the input signal of inverter driving system for varying the induction motor speed. Thus, the experimental results show that the fabricating intelligent board carried out very well the various functions in the wide operating ranges of boost pump system. This developed control module expect to apply to industrial fields to require the comparatively exact control and monitoring such as multi-motor driving system with inverter, variable air volume system and the boost pump water supply systems.

• International Journal of Control, Automation, and Systems
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• 제5권6호
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• pp.652-662
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• 2007

This paper presents a new and simple method for sensorless operation of matrix converter drives using a constant air-gap flux and the imaginary power flowing to the motor. To improve low-speed sensorless performance, the non-linearities of a matrix converter drive such as commutation delays, turn-on and turn-off times of switching devices, and on-state switching device voltage drop are modeled using PQR transformation and compensated using a reference current control scheme. The proposed compensation method is applied for high performance induction motor drives using a 3 kW matrix converter system. Experimental results are shown to illustrate the feasibility of the proposed strategy.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.2186-2191
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• 2003

This study is to investigate the effects of water induction through the air intake system on the characteristics of combustion and exhaust emissions in diesel engine. The effects of water induction through the air intake port were considered in IDI diesel engine in this study. The formation of NOx was significantly suppressed by decreasing the gas peak temperature during the initial combustion process because the water play a role as a heat sink during evaporating in the combustion chamber, but the smoke was slightly increased with increased water amount. Also, NOx significantly decreased with increase in water amount. A simultaneous reduction in smoke and NOx emissions can be obtained when water is injected into the combustion chamber by retarding the fuel injection timing more than without water injection.