• 대한전기학회논문지:전력기술부문A
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• 제48권11호
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• pp.1441-1447
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• 1999

A discrete time domain modeling is presented for the pulse-width modulated series resonant converter (PWM-SRC) with a discontinuous current mode. This nonlinear system is linearized about its equilibrium state to obtain a linear discrete time model for the investigation of small signal performances such as the stability and transient response. The usefulness of this small signal model is verified through the dynamic simulation.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.135-137
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• 2007

A phase shifted full-bridge PWM converter (PSFBC) has been used as the most popular topology for many applications. But, for the reasons of the cost and performance, the control circuits for the PSFBC have generally been implemented using analog circuits. The studies on the digital control of the PSFBC were recently presented. However, they considered only the digital implementation of the analog controller. This paper presents the modeling and design of the digital controller for the PSFBC in the discrete time domain. The discretized PSFBC model is first derived considering the sampling effect. Based on this model, the digital controller is directly designed in discrete time domain. The simulation and experimental results are provided to verify the proposed modeling and controller design.

• Journal of Power Electronics
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• 제8권3호
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• pp.201-209
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• 2008

This paper presents the modeling and design of a digital controller for a phase-shifted full-bridge converter (PSFBC) in a discrete-time domain. The discretized PSFBC model is first derived and then analyzed considering the sampling effect and the system parameters. Based on this model, the digital controller is directly designed in a discrete-time domain. The simulation and experimental results are provided to show the validity of the proposed modeling and controller design.

• 한국CDE학회논문집
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• 제19권1호
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• pp.29-40
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• 2014

Conceptual Modeling is the process of abstracting a model from a real or proposed system. It is probably the most important aspect of a simulation study. Relate works show that the elementary developers devoted little time to understanding how the systems actually worked, namely they didn't build appropriate conceptual model. Thus, the result of simulation is inconsistent because it depends on developer's competence. Although many researchers suggested various techniques enabling developer to build conceptual model, there were several limitations. In this study, to overcome the limitations of existing techniques, we proposed COMBINE-DES (COnceptual Model BuildINg framEwork using ontology for Discrete Event Simulation). The COM-BINE-DES supports expediting the conceptual modeling with Solution ontology generated by Domain ontology and Simulation ontology. Moreover, it provides consistent simulation result regardless of repeated modeling.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.705-707
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• 2004

In this paper, we propose a robust control technique against parameter uncertainties as well as external disturbances. It is robust control scheme using discrete-time state space disturbance observer. It does not require disturbance modeling, plant inverse modeling and/or Q filter. In frequency domain, its performance is evaluated in terms of sensitivity and complementary sensitivity as well as gain and phase margin. Finally we discuss design criterion of state space disturbance observer considering its performance in frequency domain.

• 전력전자학회논문지
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• 제3권4호
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• pp.338-345
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• 1998

The mathematical interpretation of a practical sampler which is useful to obtain the small signal models for the peak and average current mode controls is proposed. Due to the difficulties in applying the Shannons sampling theorem to the analysis of sampling effects embedded in the current mode control, several different approaches have been reported. However, these approaches require the information of the inductor current in a discrete expression, which restricts the application of the reported method only to the peak current mode control. In this paper, the mathematical expressions of sampling effects on a current loop which can directly apply the Shannons sampling theorem are newly proposed, and applied to the modeling of the peak current mode control. By the newly derived models of a practial smapler, the models in a discrete time domain and a continuous time domain are obtained. It is expected that the derived models are useful for the control loop design of power supplies. The effectiveness of the derived models are verified through the simulation and experimental results.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 전력전자학술대회 논문집
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• pp.275-278
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• 1998

The mathematical interpretation of a practical sampler which is useful to obtain the small signal models for the peak and average current mode controls is proposed. Due to the difficulties in applying the Shannon's sampling theorem to the analysis of sampling effects embedded in the current mode control, several different approaches have been reported. However, these approaches require the information of the inductor current in a discrete expression, which restricts the application of the reported method only to the peak current mode control. In this paper, the mathematical expressions of sampling effects on a current loop which can directly apply the Shannon's sampling theorem are newly proposed, and applied to the modeling of the peak current mode control. By the newly derived models of a practical sampler, the models in a discrete time domain and a continuous time domain are obtained. It is expected that the derived models are useful for the control loop design of power supplies. The effectiveness of the derived models are verified through the simulation and experimental results.

• 한국음향학회지
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• 제15권1호
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• pp.23-33
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• 1996

본 논문에서는 bispectra를 위한 고전적 주영역 (classical principal domain)이 2계 Volterra 모델의 출력을 결정짓는데 사용되면 그 출력은 완전하지 못하게 될 것임을 지적한다. 이러한 불완전함은 DFT의 주기적 특성과 관련이 있다. 이런 이유로, 본 논문의 목적은 비선형 시스템의 응답의 추정을 향상기키는 Volterra 커널을 위한 확장된 주영역 (extended principal domain)을 제안하는데 있다. 확장된 주영역을 정의 내리기 위하여, 2차원 DFT와 Volterra 모델의 2계 요소와 정사각형 필터와의 관계를 사용하여 이산 시간 영역 Volterra 모델에서 새로운 이산 주파수 영역의 Volterra 모델을 유도하였다. 확장된 영역이 모델의 출력에 미치는 영향을 DFT의 주기성 측면에서 해석을 하였다. 컴퓨터 모의 실험을 통하여, Volterra 모델링에서 확장된 주영역의 영향을 살펴보았다. 모의 실험 결과에 의하면, Volterra 모델의 출력을 계산하는 과정과 Volterra 모델의 계수를 추정하는데 있어서 매우 중요한 역할을 함을 알 수 있었다.

• 한국정밀공학회지
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• 제17권10호
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• pp.125-131
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• 2000

By using the test of signal error, model structure of an electrohydraulic servo system is determined. For determining parameter of the electrohydraulic servo system, using time discrete model of parametric method, parameters in time discrete model are searched by the least square method. By bilinear transform, we have found the model of electrohydraulic servo system in s domain. Afterwards, we have compared experimental data with simulation data by MATLAB having the identified parameter. As the result, experimental data is agreed with simulation data very well.

• Journal of Advanced Marine Engineering and Technology
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• 제24권1호
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• pp.94-103
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• 2000

This paper describes the model identification and the discrete-time sliding mode control of electro-hydraulic servo systems which are composed of servo valves, double-rod cylinder and load mass. The controlled plant is identified as a 3th-order discrete-time ARMAX model obtained from the prediction error algorithm, where a nominal model and modeling errors are zuantitatively constructed. The discrete sliding mode controller for 3th-order ARMAX model is designed in discrete-time domain, where all states are observed from Kalman filter. The discrete sliding mode controller has better tracking performance than that obtained from continuous-time sliding mode controller, in experiment.