• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 추계학술대회 논문집 학회본부
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• pp.207-209
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• 1991

This paper deals with voltage control method of PWM rectifier using current-controlled voltage type converter. A linearized model of the current-controlled rectifier is derived, which is used to examine the effect of controller gains to its dynamic responses. Through the simulation, it is shown that the proposed model is generally valid, which is confirmed by experimental results.

• Journal of Electrical Engineering and Technology
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• 제12권6호
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• pp.2227-2236
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• 2017

In order to solve the neutral-point voltage fluctuation problem of three-phase three-level T-type inverters (TPTLTIs), the unbalance characteristics of capacitor voltages under different switching states and the mechanism of neutral-point voltage fluctuation are revealed. Based on the mathematical model of a TPTLTI, a feed-forward voltage balancing control strategy of DC-link capacitor voltages error is proposed. The strategy generates a DC bias voltage using a capacitor voltage loop with a proportional integral (PI) controller. The proposed strategy can suppress the neutral-point voltage fluctuation effectively and improve the quality of output currents. The correctness of the theoretical analysis is verified through simulations. An experimental prototype of a TPTLTI based on Digital Signal Processor (DSP) is built. The feasibility and effectiveness of the proposed strategy is verified through experiment. The results from simulations and experiment match very well.

• 연구논문집
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• 통권26호
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• pp.5-14
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• 1996

Test results of electromagnetic suspension (EMS) type urban transit maglev system are reported. Electromagnetic levitation system is a transportation system taking advantage of the attraction of normal conducting electromagnets to support and guide the train in combination with the linear induction traction motors. Urban Transit Maglev (UTM) Which is being developed by the maglev team in KIMM and the Hyundai Precision Company since 1995 consists of three bogies. In the first year, two types of Bogies are developed. Bogie I uses an analog controller for levitation and guidance control and is driven by two linear induction motors (LIM) mounted on the right and left side of module. Bogie II uses a digital controller and is driven by one LIM mounted along the center line of the bogie. Test results reported in this paper are those obtained with Bogie II with a digital controller. Also included in this paper is a brief explanation of the electromagnetic suspension levitation system which is being developed by the maglev team in KIMM.

• KIEE International Transactions on Power Engineering
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• 제4A권3호
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• pp.129-133
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• 2004

This paper deals with the design and implementation of a TCSC (Thyristor Controlled Series Capacitor) simulator, which is a module for an analog type power system simulator. Principally, it presents configuration of controller hardware/software and its experimental results. An analog type power system simulator consists of numerous power system components, such as various types of generator models, scale-downed transmission line modules, transformer models, switches and FACTS (Flexible AC Transmission System) devices. It has been utilized for the verification of the control algorithm and the study of system characteristics analysis. This TCSC simulator is designed for 50% line compensation rate and considered for damping resister characteristic analysis. Its power rate is three phase 380V 20kVA. For hardware extendibility, its controller is designed with VMEBUS and its main CPU is TMS320C32 DSP (Digital Signal Processor). For real time control and communications, its controller is applied to the RTOS (Real Time Operation System) for multi-tasking. This RTOS is uC/OS-II. The experimental results of capacitive mode and inductive mode operations verify the fundamental operations of the TCSC.

• 제어로봇시스템학회논문지
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• 제13권4호
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• pp.344-351
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• 2007

In this paper, we propose an approach to design multi-fuzzy controllers for the superheat and the low pressure that have an influence on energy efficiency and stabilization of air conditioning system with multi-evaporators. Air conditioning system with multi-evaporators is composed of compressor, condenser, several evaporators and several expansion valves. It is quite difficult to control the air conditioning system because the change of the refrigerant condition give an impact on the overall air conditioning system. In order to solve the drawback, we design multi-fuzzy controllers which control simultaneously both three expansion valve and one compressor for the superheat and the low pressure of air conditioning system. The proposed multi fuzzy controllers are given as a kinds of controller types such as a simplified fuzzy inference type. Here the scaling factors of each fuzzy controller are efficiently adjusted by Hierarchical Fair Competition-based Genetic Algorithms. The values of performance index of the simulation results of the A company type compare with simulation results of simplified inference type.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2003년도 추계종합학술대회 논문집
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• pp.157-160
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• 2003

웹 서비스는 WSDL 서비스 인터페이스와 서비스 구현 문서를 이용하여 정적으로 호출되거나 서비스타입 정의와 UDDI를 통한 서비스 구현을 검색함으로서 동적으로 호출될 수 있다. 지금까지는 동시에 두 가지를 수행 할 수 없었다. 본 논문에서는 Model View Controller(MVC) 프레임워크를 사용한 정적/동적 웹 서비스를 지원하는 효율적인 멀티미디어 CMS(Contents Management Systems)를 설계하고 구현하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.503-506
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• 1996

An integrated Robot control system for SCARA robot is developed. The system consists of an off-line programming(OLP), software and a robot controller using four digital signal processor(TMS32OC50). The OLP has functions of teaching task, dynamic simulator, three dimensional animation, and trajectory planning. To develop robust dynamic control algorithm, a new sliding mode control algorithm for the robot is proposed. The trajectory tracking performance of these algorithm is evaluated by implementing to SCARA robot(SM5 type) using DSP controller which has conventional PI-FF control algorithm. To make SCARA robot operate according to off-line teaching, an interface between OLP and robot controller in the integrated system is designed. To demonstrate performance of the integrated system, the proposed control algorithm is applied to the system.

• 대한전기학회논문지:전력기술부문A
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• 제48권9호
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• pp.1119-1125
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• 1999

In this paper, a decentralized multilevel-adaptive controller for a boiler-turbine system is designed by using multiple model adaptive method. It is applied to the drum type boiler-turbine system which is simplified from Boryung T/P #1,2 model. A linearlized model is decomposed into three subsystems by means of linear transformation. Then the DMC based on such subsystem is designed and a Multiple Model Adaptive Control(MMAC) scheme is applied for the purpose of the good tracking to variable load demands of the thermal power plant. The good performance of the designed controller is shown by simulations in various conditions that have the large step and ramp change of power demamd.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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• pp.195-197
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• 2006

In this paper, an interface unit is designed to efficiently monitor transmission data in Controller Area Network(CAN)-based control systems. The CAN uses a serial multi master communication protocol that efficiently supports distributed real-time control with a very high level of data integrity, and communication speeds of up to 1Mbps. The interface unit is composed of a DSP controller which collects data on the CAN bus and transfers data to a personal computer via serial communication to save and display of interesting signals. The experimental system consists of three DSP controllers which represent electronic control units of a vehicle, an interface unit for analysing the data on the bus, and a graphic monitoring program coded on the Windows platform. The validity and the effectiveness of the proposed simple type of CAN interface unit are shown through the experimental results.

• 디자인학연구
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• 제18권2호
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• pp.201-210
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• 2005

본 연구에서는 복잡한 기능을 가진 A/V기기 리모컨의 사용성을 저해하는 요인은 무엇인가 파악하고, 이를 개선하기 위한 사용성 결정 인자를 설정하여 사용성 비교 실험을 수행하고, 개선안을 제시, 이 개선안이 기존의 안에 비하여 우월하다는 점을 증명하고자 한다. 리모컨의 사용성 저해 요인을 파악하기 위하여 40여종의 각종 A/V관련 제품의 리모컨을 조사 분석하였다. 이를 통하여 사용성에 영향을 미치는 인자를 추출해 내고, 차기 버전의 플레이앳티비$(Play@TV^{TM})$용 리모컨을 선정하는데 이 인자를 만족하는 3개의 안을 도출해냈다. 기존의 리모컨과 새롭게 제시하는 3개의 리모컨 안에 대하여 사용성 테스트를 수행하여, 정성적, 정량적 분석을 하였다. 분석 결과 개선안 B가, 동일한 과제를 수행하는데 기존 리모컨에 비하여 9.2% 시간이 덜 걸리는 것을 확인 할 수 있었다. 이와 같은 결과는 본 연구에서 제시하는 리모컨 사용성의 결정인자, 즉, 기능수용성, 촉각적 단서의 제공, 적절한 크기와 무게, 주요 키의 배치 방법, 관련 기능의 그룹핑 등이 제품의 사용성을 개선하는데 유효함을 보이는 것이라 하겠다.