• 대한전기학회논문지:전력기술부문A
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• 제48권9호
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• pp.1064-1072
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• 1999

The basic concepts, which are related to the PSS tuning conditions and performance conditions for the safe of determination of PSS gain and compensation of phasor lagging, are thoroughly investigated in this first part. The performance conditions, where the power system has the lowest inherent damping torque and PSS should provide maximum damping torque, are examined by analysing synchronizing torque and damping torque supplied by the voltage control loop at the oscillation frequency. PSS tuning conditions are also investigated by observing the phasor lagging and the gain, resulted from power system-generator-excitation system depending on operating conditions, such as generator active power, reactive power, transmission impedance and AVR gain. The basic concepts developed in this PartImake it possible to lay foundation for the discussion of PSS tuning in Part II.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 춘계학술대회 논문집
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• pp.469-470
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• 2008

• 한국광학회지
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• 제16권6호
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• pp.527-534
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• 2005

하나의 DFB 영역, 위상 조정 영역과 이득 영역으로 구성된 다중 전극 DFB 레이저의 pulsation 동작 특성을 살펴본다. Anti-phase (AP) complex-coupled (CC) DFB 구조를 사용한 경우가 in-phase CC DFB 구조나 index-coupled DFB 구조를 사용한 경우에 비하여 안정된 pulsation 동작이 발생하는 이득 영역과 위상 조정 영역의 전류 범위가 큼을 알 수 있다. AP CC DFB 구조를 사용한 경우 결합 세기가 커질수록, 이득 결합 계수가 커질수록 안정된 pulsation 동작이 발생하는 이득 영역의 전류 범위가 증가하고 pulsation 주파수의 튜닝 영역이 커짐을 볼 수 있다. 또한 위상 조정 영역의 위상 변화에 의한 pulsation주파수의 튜닝 영역도 커짐을 볼 수 있다. 고정된 결합 세기에서 DFB 영역의 길이가 증가할수록 pulsation 동작이 발생하는 위상 조정 영역과 이득 영역의 전류 범위가 증가하여 pulsation 주파수 튜닝 영역이 넓어짐을 볼 수 있다.

• 대한전기학회논문지:전력기술부문A
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• 제49권7호
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• pp.350-358
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• 2000

Based on the results in the first-part paper, PSS tuning methods including the determination of PSS gain and compensation of phasor lagging are investigated in this second part. In the phase compensation, PSS should compensate phase lagging, resulted from power system-generator-excitation system loop, to provide damping torque in equal phase with the generator speed. Also, PSS gain should be determined to provide maximum damping torque as much as possible without the other modes unstable. In this paper, gain tuning method using the root-locus and the phase compensation of PSS at the one machine with infinite bus system are presented. The differences between PSS tuning at the tuning condition and at the least-stable condition are also discussed.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.621-624
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• 2002

The purpose of this paper is a study on getting proper gain set of PID controller which satisfies multi-performance specifications of the control system. The multi-objective optimization method is introduced to evaluate specifications, and the genetic algorithm is used as an optimal problem solver. To enhance the performance of genetic algorithm itself, adaptive technique is included. According to the proposed method in this paper, finding suitable gain set can be more easily accomplishable than manual gain seeking and tuning.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.306-308
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• 2006

산업현장에서 가장 많이 활용되고 있는 PID제어기의 이론적인 배경을 토대로 실제 DCS 기반 플랜트에서 PID Tuning Method에 의한 PID제어기를 구현하고 제어성능을 확인한다. 또한 DCS(Distribute Control System)의 PID Controller를 분석하고 전 공정제어 System 중 일부분을 ARMA Modeling하여 만족스런 성능이 구현되도록 최적의 PID gain Parameter를 찾는다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 ICEIC The International Conference on Electronics Informations and Communications
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• pp.218-220
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• 2004

A new wide-band VCO topology using Miller capacitance is proposed. Contrary to conventional VCO using the Miller capacitance where the variable amplifier gain is negative, the proposed VCO uses both the negative and positive variable amplifier gain to enhance the frequency tuning range significantly. The proposed VCO is simulated using HSPICE. The simulations show that 410MHz and 220MHz frequency tuning range are obtained using the negative .and positive variable amplifier gain, respectively. The tuning range of the proposed VCO is $23\%$ of the center frequency(2.8GHz). The phase noise is -104dBc/Hz at 1MHz offset by simple model. The operating current is only 3.84mA at 2.5V power supply.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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• pp.358-363
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• 2003

Optimal tuning plays an important role in operations or tuning of the complex process such as the main steam temperature of the thermal power plant. However, it is very difficult to maintain the steam temperature of power plant using conventional optimization methods, since these processes have the time delay and the change of the dynamic characteristics in the reheater. Up to the present time, the Pm controller has been used. However, it is not easy to achieve an optimal PID gain with no experience, since the gain of the PID controller has to be manually tuned by trial and error. This paper suggests immune algorithm based tuning technique for PID Controller on steam temperature process with long dead time and its results are compared with genetic algorithm based tuning technique.

• 대한전기학회논문지:시스템및제어부문D
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• 제54권12호
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• pp.705-712
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• 2005

This paper deals with speed-sensorless control of an AC servo motor using Fuzzy-Tuning High Gain Observer(FTHGO). Resolver or encoder can be used to measure a rotor speed, but it has a limit to detect motor speed precisely. To solve this problem, it is studied to measure a speed of an AC servo motor without sensor. In this paper, the gain of an observer to estimate motor speed is properly set up and designed using the fuzzy control theory. It calculates the differentiation of the rotor current of the AC motor and estimates the rotor speed using it. Proposed speed sensorless control is performed using the estimated speed as the control variable. Designed FTHGO is applied to AC servo motor to verify the feasibility of the proposed observer. Feasibility of the FTHGO proposed in this paper is proven comparing the experimental results with/without the speed sensor.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 추계학술대회 논문집
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• pp.521-522
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• 2008