• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.890-895
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• 2005

This paper presents the dynamic analysis of a cantilever beam undertaking impulsive force that undergoes rigid body motion. The transient response of the beam induced by the impulsive force and the rigid body motion is calculated based on hybrid deformation variable modeling method by applying the Rayleigh-Ritz assumed mode method. The stiffness variation effect caused by the rigid body motion is considered in this modeling. The effects of the impulsive force position and the angular velocity on the transient responses of the beam are investigated through numerical studies.

• 한국소음진동공학회논문집
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• 제24권10호
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• pp.788-794
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• 2014

In this paper, the transient response analysis of the trapezoidal corrugated plate subjected to the pulse load is investigated by the theoretical method. Three types of pulse loads are considered: stepped, isosceles triangular and right triangular pulse loads. The corrugated plates can be represented as an orthotropic plate. Both the effective extensional and flexural stiffness of this equivalent orthotropic plate are considered in the analysis. The plate is stiffened by concentric stiffeners perpendicular to the corrugation direction. The stiffening effect is represented by the discrete stiffener theory. This theoretical results are validated by those obtained from 3D finite element analysis based on shell elements. Some numerical results are presented to check the effect of the geometric properties.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1264-1266
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• 2005

This paper analyzes static and transient response characteristics of a permanent magnet type stepping motor with claw poles using three-dimensional finite element method. The outer diameter of the stepping motor to be analyzed is approximately 6 mm. In this paper we analyzes only 2 poles of the stepping motor, which has 10 magnetic poles made up of NdFeB material, using periodic boundary condition. We clarify transient response and static torque charateristics using Maxwell 3D and Matlab Simulink.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.1221-1222
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• 2010

• 조명전기설비학회논문지
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• 제21권5호
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• pp.82-89
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• 2007

여자제어 시스템의 AVR(Automatic Voltage Regulator) 장치는 발전기의 출력 전압을 일정하게 유지시키기 위하여, 여자기의 전압 또는 전류를 발전기 부하 전류 및 전압 변동에 따라 제어하는 역할을 수행한다. 이러한 AVR 장치의 응답성과 제어 특성은 발전기의 부하 변동 또는 과도 응답 상태에서의 출력 특성을 결정하게 된다. 본 논문에서는 고성능 전동기 제어 시스템에 널리 사용되고 있는 PWM 제어 시스템과 부하 변동에 강인하게 동작할 수 있는 과도 응답 보상기를 적용한 고성능 여자 시스템을 제안한다. 과도 응답 보상기는 발전기의 부하 전류 변동에 따라, 여자기의 제어신호를 PID 제어기의 출력에 더하여 빠른 속응성과 안정성을 가지도록 함으로써, 발전기의 출력 전압을 안정적으로 공급할 수 있도록 제어한다. 제안된 고성능 여자 시스템은 컴퓨터 시뮬레이션과 소형 발전기 시스템에 적용된 실험을 통하여 그 성능을 검증하였다.

• 한국항공운항학회지
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• 제17권1호
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• pp.9-16
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• 2009

The analysis of an aircraft flight dynamics is recently very convenient because of the introduction of state-space method and a well-developed package software. The representation of a dynamic system is described as a simple form of matrix calculation and the unique form of model is available for the linear or nonlinear, time variant or time invariant, mono variable or multi variable system with state-space method. And this analysis can be simplified with the specific functions of a package software and it is very simplified to execute the simulation of the dynamic characteristics for an aircraft model with an interactive graphical treatment. The purpose of this study is to develope an educational flight simulator for the students who need to analyze the dynamic characteristics of an aircraft that is primarily to execute the simulation for the analysis of the transient response and frequency response of an aircraft stability. Furthermore the dynamic characteristics of an aircraft motion is set up as dynamical animation tool for the control response on 3-axis motions of an aircraft.

• Smart Structures and Systems
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• 제17권5호
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• pp.753-771
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• 2016

This paper addresses the free and transient responses of a SDOF linear complex stiffness system by making use of the Hilbert transform and the convolution integral. Because the second-order differential equation of motion having the complex stiffness give rise to the conjugate complex eigen values, its time-domain analysis using the standard time integration scheme suffers from the numerical instability and divergence. In order to overcome this problem, the transient response of the linear complex stiffness system is obtained by the convolution integral of a green function which corresponds to the unit-impulse free vibration response of the complex system. The damped free vibration of the complex system is theoretically derived by making use of the state-space formulation and the Hilbert transform. The convolution integral is implemented by piecewise-linearly interpolating the external force and by superimposing the transient responses of discretized piecewise impulse forces. The numerical experiments are carried out to verify the proposed time-domain analysis method, and the correlation between the real and imaginary parts in the free and transient responses is also investigated.

• 수산해양교육연구
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• 제7권1호
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• pp.111-126
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• 1995

In general, the electromagnetic transient phenomenon always exists in induction motor(IM) with the torque change. The control performance of IM is very worse than that of D.C motor owing to this transient phenomenon. So many studies about the elimination methods of the transient phenomenon have been making progress. Interesting methods of them are the Field acceleration method(FAM) and the method of impulse addition on the input voltage at the time point of torque change. In this paper, first, the circuit equation of IM is derived from the phase segregation method. The torque equation consisted of the stator and rotor currents is derived from the solving of the circuit equation. As we well known, the transient terms exist in this the torque equation. The method of impulse addition on the input voltage at the instance of torque change is confirmed theoretically for the elimination of the transient phenomenon. With the base on it, the author proposed a real time algorithm to eliminate the transient terms. The control system is consisted of the PI controller with the feedforward of torque change. The author could confirm that the quick stepwise responses of torque and speed can be obtained from response simulations.

• JSTS:Journal of Semiconductor Technology and Science
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• 제17권2호
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• pp.288-293
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• 2017

Transient simulation capability with an implicit time derivation method is a missing feature in deterministic Boltzmann equation solvers. The H-transformation, which is critical for the stable simulation of nanoscale devices, introduces difficulties for the transient simulation. In this work, the transient simulation of graphene sheets is reported. It is shown that simulation of homogeneous systems can be done without abandoning the H-transformation, as much as a specially designed discretization method is employed. The AC mobility and step response of the graphene sheet on the $SiO_2$ substrate are simulated.

• Journal of Electrical Engineering and Technology
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• 제7권5호
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• pp.672-680
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• 2012

This paper proposes the control strategy of the shunt Flexible AC Transmission System (FACTS) devices to improve transient stability in multimachine power system. The multimachine power system has high nonlinear response after severe disturbance. The concept of Lyapunov energy function is applied to derive nonlinear control strategy and it was found that the time derivative of line voltage is not only can apply to control the shunt FACTS devices in multimachine system but also is locally measurable signal. The fuzzy logic control is also applied to overcome the uncertainty of various disturbances in multimachine power system. This paper presents the method of investigating the effect of the shunt FACTS devices on transient stability improvement. The proposed control strategy and the method of simulation are tested on the new England power system. It was found that the shunt FACTS devices based on the proposed nonlinear control strategy can improve transient stability of multimachine power system.