• 전자공학회논문지B
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• 제30B권11호
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• pp.27-36
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• 1993

It is well know that the tuning method of Yuwana-Seborg (1982) can not be even applied to the relatively small delay system due to the phase errors from the Pad approximation suh (1984, 85, 86). Jutan and Rodriguez(1984), lee(1989), Chen(1989), Lee and Edgar(1990), etc have been tried to improve it. In this stydy, such recent results and their problems are investigated. A new tuning method by "a frequency scale transformation". which is based on a previous result of Suh(1984). is proposed. It can reduce the magnitude of the phase error significantly.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.47.6-47
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• 2001

In this paper a new indirect robust self-tuning regulator is proposed including an inverse system of a plant and a robust compensator such that it achieves the desired frequency shape specified by solving the mixed H$\infty$ sensitivity problem within a prescribed tolerance in the H$\infty$ norm. Consequently, in the proposed self-tuning regulator, robust stability is guaranteed in spite of the identification error.

• Current Optics and Photonics
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• 제2권1호
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• pp.53-58
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• 2018

A novel X-band high speed frequency sweep signal generator based on a tunable optoelectronic oscillator (OEO) incorporating a frequency-swept laser is presented and the theoretical fundamentals of the design are explained. A prototype of the generator with tuning range from 8.8552 GHz to 10.3992 GHz and a fine step about 8 MHz is achieved. The generated radiofrequency signal with a single sideband (SSB) phase noise lower than -100 dBc/Hz@10KHz is experimentally demonstrated within the whole tunable range, without any narrow RF band-pass filters in the loop. And the tuning speed of the frequency sweep signal generator can reach to over 1 GHz/s benefiting from applying a novel dispersion compensation modular instead of several tens of kilometers of optical fiber delay line in the system.

• 한국정밀공학회지
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• 제18권11호
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• pp.58-66
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• 2001

GPC has been reported as a useful self-tuning control algorithm for systems with unknown time-delay and parameters. GPC is easy to understand and implement, and thus has won popularity among many practicing engineers. Despite its success, GPC does not guarantee is nominal stability. So, in this paper, GPC is rederived in frequency domain instead of in the time domain to guarantee its nominal stability. Derivation of GPC in frequency domain involves spectral factorization and Diophantine equation. Frequency domain GPC control law is stable because the zeros of characteristic polynomial are strictly Schur. Recursive least square algorithm is used to identify unknown parameters. To see the effectiveness of the proposed controller, the controller is simulated for a numerical problem that changes in dead-time, in order and in parameters.

• 한국군사과학기술학회지
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• 제8권3호
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• pp.64-72
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• 2005

In this paper, we propose a design method of the millimeter-wave(W-Band) waveguide cavity harmonic voltage controlled oscillator(VCO) using a Gunn diode for the armor sensor. Using the 3-dimensional simulation tool(Ansoft $HFSS^{TM}$), we were able to find the impedance matching point between waveguide and Gunn diode and estimate the oscillation frequency. A varactor diode is used for the frequency tuning, and we find out the equation for the calculation of the tunable frequency range. The designed VCO shows good performances; 17dBm output power at 94GHz center frequency, 520MHz frequency tuning range similar to the estimated value(480MHz).

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1380-1385
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• 2004

In this paper, auto-tuning technique of the PID controller gain by particle swarm optimization algorithm is presented. PID controller is easy to implement to numerous control systems. After PID gain tuning is completed, its result could be implemented to control spacecraft vibration such as jitter that is high frequency vibration usually over 10Hz. The off-line PID controller tuning is done under system nonlinearities and uncertainties existence, then its result is applied to control experiment device to prove the PSO efficiencies.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.1049-1053
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• 2002

An unconstrained tuning fork with a 3-D model has been numerically analyzed by Finite Element Method (FEM) and Boundary Element Method (BEM). The first three natural frequencies were calculated by the FEM modal analysis. Then the change of the modal frequencies was examined with the variation of the tuning fork length and width. Analytical model equations were derived from the numerically relating results of the modal frequency-tuning fork length by approximating minimization. Finally the BEM was used for the sound pressure field calculation from the structural displacement data.

• 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.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 추계학술대회 논문집 전력기술부문
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• pp.321-322
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• 2008

주파수는 발전기 조속기와 전적거래소 EMS AGC의 협조제어 체계가 적절하여야 안정적인 운영이 가능하며, 과다한 주파수 조정은 경제급전을 저해함은 물론 발전기의 수명단축을 초래하기 때문에 AGC 최적튜닝은 필수적이다. 본 논문에서는 '07년도에 거래소 계통운영처에서 수행한 AGC 제어파라미터 튜닝기법 및 효과에 대해 논하고 있으며, 학계는 물론 동종업계에 AGC 관련 기술개발시 업무추진에 도움이 되었으면 한다.

• 전기학회논문지
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• 제63권7호
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• pp.883-888
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• 2014

The paper describes the parameter tuning of power system stabilizer (PSS) for a power plant based on hybrid system modeling. The existing tuning method based on bode plot and root locus is well applied to keep power system stable. However, due to linearization of power system and an assumption that the parameter ratio of the lead-lag compensator in PSS is fixed, the results cannot guarantee the optimal performances to damp out low-frequency oscillation. Therefore, in this paper, hybrid system modeling, which has a DAIS (differential-algebraic-impusive-switched) structure, is applied to conduct nonlinear modeling for power system and find optimal parameter set of the PSS. The performances of the proposed method are carried out by time domain simulation with a single machine connected to infinite bus (SMIB) system.