• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2003년도 추계학술발표논문집
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• pp.217-229
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• 2003

지종교체시 지절현상등의 사고를 방지하기 위하여 short circulation에 영향을 주는 요소들을 분석하고 이들 상호간의 관계를 파악하는 것은 매우 중요하다. 본 연구에서는 공정 출력변수가 원하는 값으로 유지되기 위해서 입력변수를 어떻게 조절해 주어야 하는지를 규명하기 위하여 short circulation에 대한 동적 모델식을 구한 후 정상상태 운전 데이터를 이용하여 입력변수의 변화에 따른 응답 특성을 조사하였고 아울러 입력변수들의 상호작용 특성을 규명하였다.

• Journal of Power Electronics
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• 제4권3호
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• pp.180-187
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• 2004

This paper proposes a new control strategy for the dynamic voltage restorer (DVR). It is based on a synchronous PI decoupling control strategy which features fast response time and low steady state error. Therefore, the proposed control strategy produces faster action time against voltage sag and guarantees more than enough compensation for reduced supply voltage. Experimental results, implemented with the TMS320C3${\times}$DSP control unit, are shown to validate the effectiveness of the proposed control strategy.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 D
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• pp.686-688
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• 2000

In this paper, a new method for system identification is proposed. Unknown dynamic system is identified to the second order transfer function, which can be applied to PID controller design. First, overshoot$(o_s)$, settling time$(t_s)$, and steady state value$(y_{ss})$ are obtained from the step response of unknown dynamic system. And then, we can get the second order transfer function using equations which are extracted from those three parameters$(o_s,t_s,y_{ss})$ through mathmatical analysis. In addition, simulation is carried out to show excellent performance of proposed identification method compare with other.

• Journal of Mechanical Science and Technology
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• 제16권6호
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• pp.819-828
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• 2002

An analytical method is presented for evaluation of the steady state periodic behavior of nonlinear systems. This method is based on the substructure synthesis formulation and a MS (multiple scales) procedure, which is applied to the analysis of nonlinear responses. The proposed procedure reduces the size of large degrees-of-freedom problem in solving nonlinear equations. Feasibility and advantages of the proposed method are illustrated with the nonlinear rotating machine system as an example of large mechanical structure systems. In addition, its efficiency for nonlinear response prediction will be shown by comparison of other conventional methods.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.5-8
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• 2007

In this paper, numerical investigation has been carried out to study performance of methane autothermal reformer and dynamic behavior for light-off under various operating conditions. In order to simulate the given problems, numerical methods are incorporated using finite-volume method. In addition, porous medium approach is accepted because the catalytic phenomena occur in porous media. Also, start-up issue is significant in autothermal reformer although the reaction is marginally exothermic. Thus, in this study transient behavior has been also investigated to find out optimal operating conditions for start-up.

• Journal of Electrical Engineering and Technology
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• 제9권6호
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• pp.1900-1908
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• 2014

This paper establishes a compact and practical model for a water-wall system comprising supercritical once-through boilers, which can be used for automatic control or simple analysis of the entire boiler-turbine system. Input and output variables of the water-wall system are defined, and balance equations are applied using a lumped parameter method. For practical purposes, the dynamic equations are developed with respect to pressure and temperature instead of density and internal energy. A comparison with results obtained using APESS, a practical thermal power plant simulator developed by Doosan Heavy Industries and Construction, is presented with respect to steady state and transient responses.

• Journal of Power Electronics
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• 제9권3호
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• pp.386-395
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• 2009

In this paper, a new control algorithm for the dynamic voltage restorer (DVR) is proposed to regulate the load terminal voltage during various power quality problems that include sag, swell, harmonics and unbalance in the voltage at the point of common coupling (PCC). The proposed control strategy is an Adaline (Adaptive linear element) Artificial Neural Network (ANN) and is used to control a capacitor supported DVR for power quality improvement. A capacitor supported DVR does not need any active power during steady state because the voltage injected is in quadrature with the feeder current. The control of the DVR is implemented through derived reference load terminal voltages. The proposed control strategy is validated through extensive simulation studies using the MATLAB software with its Simulink and SimPower System (SPS) toolboxes. The DVR is found suitable to support its dc bus voltage through the control under various disturbances.

• Journal of Power Electronics
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• 제15권6호
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• pp.1577-1583
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• 2015

In this research, a combined adaptive-robust current controller is developed for non-minimum-phase DC-DC converters in a wide range of operations. In the proposed nonlinear controller, load resistance, input voltage and zero interval of the inductor current are estimated using developed adaptation rules and knowing the operating mode of the converter for the closed-loop control is not required; hence, a single controller can be employed for a wide load and line changes in discontinuous and continuous conduction operations. Using the TMS320F2810 digital signal processor, the experimental response of the proposed controller is presented in different operating points of the buck/boost converter. During transition between different modes of the converter, the developed controller has a better dynamic response compared with previously reported adaptive nonlinear approach. Moreover, output voltage steady-state error is zero in different conditions.

• Journal of Power Electronics
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• 제14권6호
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• pp.1263-1271
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• 2014

A novel hysteresis PWM control strategy for synchronous buck converter is proposed. The proposed control strategy is based on ampere-second balance of the modulate capacitor, which not only offers faster transient response to meet the challenges of the power supply requirements of fast dynamic load changes, but also provides better stability and solves the compensation problem of error amplifier in the conversional voltage PWM control. Finally, the steady-state and dynamic operation of the control method is analyzed and verified by simulation and experimental results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 추계학술대회 논문집 학회본부
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• pp.53-55
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• 1988

The application of Sliding Mode Control for inproving the dynamic response of a Multi-Phase-Bipolar (MPB) Brushless DC motor based position Brushless DC motor system is presented. Sliding Mode Control gives fast dynamic response with no overshoot and zero steady state error. It has the important feature of bins highly robust. A design procedure is outlined for the Sliding Mode Controller for a MPB Brushless DC motor. Digital computer simulation of the overall position control system is carried out using a time domain model in the d-q reference frame.