• 조명전기설비학회논문지
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• 제24권10호
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• pp.42-48
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• 2010

The Microsource has to supply high quality Power that has high reliability and high energy efficiency to Load according to operating type of Microgrid. The energy sources of microsource type have various dynamic characteristic and transient response corresponding to classes and application skill. This paper shows dynamic characteristic of Microgrid according to Energy Source of microsource type. This research has been carried out by detailed modelling of Microturbine system and Fuelcell system. All models are realized by EMTP/RV and simulated change of operating type and load increase within Microgrid of DC constant voltage inverter model and Microturbine, Fuelcell based Microsource.

• 한국정밀공학회지
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• 제23권8호
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• pp.145-153
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• 2006

To minimize the possible leakage of microwave when one opens the door of a microwave oven during its operation, a structural design of the reinforcing brackets for the door frame is presented. Twisting deformation of the door frame resulting from a dynamic pulling force is analyzed by harmonic and transient response analyses. Several types of the reinforcing brackets weldable to the right flange of the door frame is taken into consideration, and their effects to the twisting deformation of the door frame are compared and evaluated. As a conclusion, a thick step-shaped bracket, which is welded to whole length of the right flange, is favorable.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2003년도 춘계학술대회 논문집
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• pp.137-142
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• 2003

An analysis of the turbo-blower shaft attached to fuel cell using 3-D FEA (Finite Element Analysis) is proposed by Lanczos algorithm. The modal analysis was peformed in order to investigate natural frequencies for 10 times. It is found that the first mode of natural frequency is 111.243 and the maximum displacement is 0.16mm Consequently, It is found that the dynamic design of turbo-blower shows a good responses transiently.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.238-241
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• 1997

The recent trend toward increased use of the once-through supercritical boiler worldwide is mainly due to its rapid response. The transient behavior of the steam generator are essential in the study of the system performance of power plants as well as for the design of their appropriate control systems. In this paper, a mathmatical model of the once-through supercritical pressure boiler is obtained by simulating a set of nonlinear differential and algebraic equations.

• 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.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.388-391
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• 2003

Disturbance observer(DOB) is effective to enhance the performance of system in the presence of disturbances. Various types of disturbance observer have been proposed to improve sensitivity function of system. However, it has been observed that current DOBs tend to bring poor transient response due to cross-couplings. This paper proposes a new type of disturbance observer to reduce effect of cross-couplings and provide simpler structure than Dual DOB. Finally, we verify the performance of the proposed DOB through numerical simulations.

• Journal of Power Electronics
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• 제12권1호
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• pp.104-112
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• 2012

In this paper a new method for the design of a simple PI controller is presented and it has been applied in the control of a Boost based PFC rectifier. The Strength Pareto evolutionary algorithm, which is based on the Pareto Optimality concept, used in Game theory literature is implemented as a multi-objective optimization approach to gain a good transient response and a high quality input current. In the proposed method, the input current harmonics and the dynamic response have been assumed as objective functions, while the PI controller's gains of the PFC rectifier (Kpi, Tpi) are design variables. The proposed algorithm generates a set of optimal gains called a Pareto Set corresponding to a Pareto Front, which is a set of optimal results for the objective functions. All of the Pareto Front points are optimum, but according to the design priority objective function, each one can be selected. Simulation and experimental results are presented to prove the superiority of the proposed design methodology over other methods.

• 한국소음진동공학회논문집
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• 제19권2호
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• pp.146-154
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• 2009

Dynamic response of a hull mounted sonar(HMS) to shocks transmitted through hull structures is analyzed and then the structural reliability of the sonars is evaluated. Finite element model of the hull mounted sonar is established and the transient responses to the shock is calculated using MSC.NASTRAN. According to BV043, the maximum allowable accelerations at the foundation of the sonar are converted from the shock spectra allowable for HMS. They are applied vertically and horizontally, respectively, using the large mass method. The structural reliability is evaluated by comparing the von-Mises stresses with the material yield stress. The drum for sensors shows a high reliability owing to mounts by which the shock waves from the base structure are well protected. However, the mounts between the base structure and the drum to mount sensors show a high stress intensity. The base structure also reveals a high stress intensity at the connection points to the hull.

• 전기학회논문지P
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• 제58권4호
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• pp.427-431
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• 2009

In this study, the dynamic characteristic of a contact wire and pantograph suppling electrical power to high-speed trains are investigated from an electrical response point of view. To analysis power line disturbance by induced contact loss phenomenon for high speed operation, a hardware Simulator which considered contact loss between contact wire and the pantograph as well as contact wire deviation is developed. It is confirmed that a contact wire and pantograph model are necessary for studying the dynamic behavior of the pantograph system. One of the most important needs accompanied by increasing the speed of high-speed train is reduced that an arc phenomenon by loss of contact brings out EMI. In case of a high-speed train using electrical power, as comparison with diesel rolling stock, PLD(Power Line Disturbance) such as harmonic, transient voltage and current, EMI(Electromagnetic Interference), dummy signal injection etc usually occurs. Throughout experiment, it is verified that an arc phenomenon is brought out for simulator operation and consequently conducted noise is flowed in electric circuit by power line disturbance.

• Nuclear Engineering and Technology
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• 제43권3호
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• pp.243-256
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• 2011

This paper considers the concept of analog computing based on a cellular neural network (CNN) paradigm to simulate nuclear reactor dynamics using a time-dependent second order form of the neutron transport equation. Instead of solving nuclear reactor dynamic equations numerically, which is time-consuming and suffers from such weaknesses as vulnerability to transient phenomena, accumulation of round-off errors and floating-point overflows, use is made of a new method based on a cellular neural network. The state-of-the-art shows the CNN as being an alternative solution to the conventional numerical computation method. Indeed CNN is an analog computing paradigm that performs ultra-fast calculations and provides accurate results. In this study use is made of the CNN model to simulate the space-time response of scalar flux distribution in steady state and transient conditions. The CNN model also is used to simulate step perturbation in the core. The accuracy and capability of the CNN model are examined in 2D Cartesian geometry for two fixed source problems, a mini-BWR assembly, and a TWIGL Seed/Blanket problem. We also use the CNN model concurrently for a typical small PWR assembly to simulate the effect of temperature feedback, poisons, and control rods on the scalar flux distribution.