• 동력기계공학회지
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• 제1권1호
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• pp.144-153
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• 1997

The magnetic levitation system is utilized in the magnetic bearing of high-speed rotor because of little friction, no lubrication, no noise and so on. The magnetic levitation system need the feedback controller for the stabilization of system, and gap sensors are generally used to measure the gap. The use of gap sensors brings out the increase of the number of troublesome, and the decrease of the control performance because of the dislocation between the measurement point and the control point. This paper presents the design of the gap estimation circuit for the sensorless method proposed by authors in the magnetic levitation system. We made the gap estimation circuit which was composed of both the superposition circuit and the measuring circuit. And we investigated the validity of the usefulness of the proposed sensorless method in the magnetic levitation system through results of actual experiment.

• 드라이브 ㆍ 컨트롤
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• 제13권2호
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• pp.51-58
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• 2016

The present study deals with the issue of clamping force control of an injection molding machine using 2-way cartridge valve based logic circuit. The operating principle for the cartridge valve is described with its construction and static opening behavior. Basic module circuits are designed first and analysed according to the basic functions. Then they are combined with a virtual design model for the clamping mechanism to simulate the control performance of the overall system. The backlash inherent in the mechanism is considered while evaluating the time-delay in the process of clamping force build-up. The effects of a couple of design parameters in backlash, i.e., interval and stiffness have been demonstrated in the time-domain.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2011년도 전력전자학술대회
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• pp.314-315
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• 2011

This paper introduces the design and control method of braking chopper circuit which can supply input power to ventilation inverter of traction control system. The DC input voltage from auxiliary block (static inverter) is normally used as an input of ventilation inverter. It converts DC input to AC output voltage to drive cooling fans for traction control system and traction motors. The electrical braking force is very important for high speed train to guarantee safety even though the train is running in the dead section where the pantograph voltage is not supplied. When the high speed train decelerate speed in dead section, the regenerative energy is dissipated by braking resistor. This paper proposed the braking chopper control method to implement rheostatic braking function and the appropriate chopper circuit for supplying voltage source to ventilation inverter during rheostatic braking mode. The proposed chopper circuit makes it possible for traction control system to regenerate power continuously regardless of the existence of pantograph voltage. The feasibility of proposed braking chopper control and circuit were proven by inertia load test and actual train field test.

• 한국산학기술학회논문지
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• 제20권7호
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• pp.52-60
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• 2019

차기${\bigcirc}{\bigcirc}$함(FFX) Batch-I 및 차기${\bigcirc}{\bigcirc}$함(LST-II)에 적용된 가변피치프로펠러(CPP) 제어회로는 타 계통에서 접지 현상 발생 시 후진피치 발생이 가능할 수 있으므로, 접지 현상 발생 시에도 피치를 유지할 수 있도록 CPP 제어회로를 개선하는 것이 본 연구의 목적이었다. CPP 제어회로는 전압차이입력으로 프로펠러 각도를 변화시키므로 입력전압이 순간적으로 변동이 생기는 경우 취약할 수 있는 설계구조를 가지고 있었다. 위의 문제를 해결하기 위해서 CPP 제어회로 설계 개선 방안으로 제어전선의 끝단에 종단저항을 적용하고, 제어전선 사이에 Signal Converter를 적용하였다. 그리고 CPP 제어회로 설계 개선에 문제가 없는지 검증하기 위해, 차기${\bigcirc}{\bigcirc}$함(LST-II)으로 실제 항해 시운전에서 CPP 피치 변화 제어를 테스트 하였다. Command 피치 값과 Feedback 피치 값 사이는 매우 유사한 값을 보여주고 있으므로, CPP 제어회로의 제어신호 전달에는 문제가 없기에 적합한 개선방안으로 확인되었다.

• 한국산업정보학회논문지
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• 제12권2호
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• pp.79-84
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• 2007

본 논문에서는 CMOS를 이용한 온도 제어회로를 MOSIS의 0.25um-3.3V CMOS 설계규칙에 따라 설계하고 SPICE 시뮬레이션과 실험을 통하여 성능을 검토하였다. 설계된 회로는 $0^{\circ}C{\sim}150^{\circ}C$의 온도 범위에 대하여 출력 전압이 약 $13mV/^{\circ}C$로 변화하며 좋은 온도 선형성을 나타내었다. 또한, 바이어스 전압을 변화시키면 온도변화에 대한 출력전압의 변화량을 조정할 수 있다. 제안된 회로는 온 칩 수정발진회로의 설계 등에 유용하게 사용될 수 있을 것으로 기대된다.

• 한국군사과학기술학회지
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• 제5권1호
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• pp.45-58
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• 2002

In this paper, we designed the circuit of drive control for towing winch. It is composed of reference voltage circuit for driving voltage reference, low pass filter circuit for noise reduction, dead zone circuit for initial transient input, and driving circuit for drum direction/velocity control. Also it is realized a drive control circuit for towing winch drum in accordance with PWM(pulse width modulation) method to suit it's purpose of a large capacity driving system. The performance of the designed circuit is analyzed by experiments and the appliablity for driving the towing winch drum satisfactorily is evaluated through a various testing.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.947-950
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• 1999

The PLD design of new scheme LCD driver circuit is described in this paper. A new scheme LCD driver circuit doesn't used microprocessor for the convenience of users. A new scheme LCD driver circuit consists of 4 main parts, that is, a serial/parallel communication control block part, a LCD controller part, a LCD driver part and a RAM/ROM control block part. The validity and efficiency of the proposed LCD driver circuit have been verified by simulation and by ALTERA EPM7192SQC160-15 PLD implementation in VHDL. After comparing this LCD driver circuit to specify it was verified that the developed LCD driver circuit showed has good performances, such as low cost, convenience of users.

• 대한전기학회논문지
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• 제36권2호
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• pp.107-113
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• 1987

A complete design of a new digital control circuit for a three-phase controlled rectifier is presented. The circuit consists of a gating signal generating ROM, down counter and adder. Proposed scheme is simple and quite adequate to the microprocessor-based digitally controlled systems. The basic principle and operation characteristics of the circuit are described and experimental-results show good dynamic performance. Synchronization problem with noisy reference is also discussed. The basic phylosophy developed can be extended to the other phase control system, e.g., cycloconverters, ac voltoge controllers, etc.

• 한국전자통신학회논문지
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• 제18권4호
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• pp.617-624
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• 2023

최근, 전자 제품의 소형화와 저소비전력화 및 향상된 효율과 역률개선이 큰 관심 사항이 되고 있다. 본 논문에서는 PWM 제어기반의 AC-DC 컨버터를 설계, 제작하였다. AC-DC 컨버터는 하나의 정류회로와 하나의 출력전압 제어 회로가 직렬로 연결되는 구조로 설계하였으며, 정류회로는 다이오드 기반 단상 전파전류 회로, 출력전압 제어 회로는 PWM 제어기반의 DC-DC 변환 회로를 적용하였다. PWM 제어를 위한 주 제어장치로 아두이노를 이용하였으며, LCD를 출력 단에 구성하여 제어 결과를 확인할 수 있도록 하였다. 시험회로를 통한 반복 실험들을 통해서 오실로스코프와 LCD에 디스플레이 되는 출력전압과 목표 출력전압의 오차를 확인하였으며, 오실로스코프 측정값을 기준으로 약 5%의 오차율을 보임으로써 제안된 설계 방법론의 유효성을 확인할 수 있었다.

• Journal of Power Electronics
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• 제16권4호
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• pp.1256-1267
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• 2016

Distributed stray inductance exerts a significant influence on the turn-off voltages of power switching devices. Therefore, the design of low stray inductance bus bars has become an important part of the design of high-power converters. In this study, we first analyze the operational principle and switching transient of a T-type converter. Then, we obtain the commutation circuit, categorize the stray inductance of the circuit, and study the influence of the different types of stray inductance on the turn-off voltages of switching devices. According to the current distribution of the commutation circuit, as well as the conditions for realizing laminated bus bars, we laminate the bus bar of the converter by integrating the practical structure of a capacitor bank and a power module. As a result, the stray inductance of the bus bar is reduced, and the stray inductance in the commutation circuit of the converter is reduced to more than half. Finally, a 10 kVA experimental prototype of a T-type converter is built to verify the effectiveness of the designed laminated bus bar in restraining the turn-off voltage spike of the switching devices in the converter.