• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.192-194
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• 2007

This paper proposes a new wind turbine simulator using a squirrel cage induction for control performance test of DFIG (doubly-fed induction generator). The turbine static characteristics are modeled using the relation between the turbine torque versus the wind speed and the blade pitch angle. The turbine performance is subjected to a real wind speed pattern by modeling the wind speed as a sum of harmonics with a wide range of frequency. The turbine model includes the effect of the tower shadow and wind shear. A pitch angle controller is designed and used to protect the coupled generator by limiting the turbine speed to the maximum value. Experimental results are provided for a 3[kW] wind turbine simulator at laboratory.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.311-314
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• 1995

Biped locomotion can be simply modeled as a linear inverted pendulum mode. This model considers only the CG (center of gravity) of the entire system. But in real biped robot systems, the free-leg motion dynamics is not negligible. So if its dynamics is not considered in designing the reference CG motion, it is badly influence to the ZMP(zero moment point) position of the biped robot walking in the sagittal plane. Therefore, we modeled the biped locomotion similar to the linear inverted pendulum mode but considered the predetermined free-leg dynamics. To verify that the proposed biped locomotion is more stable than the linear inverted pendulum mode, we constructed a biped robot simulator and designed a serco controller to track both the reference motion of the free leg and the reference motion of CG of the biped robot using the computed torque control low. And through simulations, we verified that the proposed walking is better in stability than the one based on the linear inverted pendulum mode.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.5
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• pp.1013-1018
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• 2003

This paper deals with the secondary excited induction generator applied to random energy input generation system. As it is preferred to stabilize the output voltage and frequency in the constant level, microcomputer controlled inverter connected to the secondary windings supplies the secondary current with slip frequency. For testing the appropriateness of this paper, the input torque simulator, which generate the statistically varied wave power input torque in the laboratory to drive the secondary excited induction generator, are constructed. The experimental and numerical results show the advantage of secondary excited induction generator system for the random input wave generation system.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1997.10a
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• pp.115-118
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• 1997

Recently, hot rolling oil lubrication technology is required to face with the new environments such as the rapid introduction of high wear resistent high speed steel roll the development of continuous hot rolling technology. In the hot strip mill, according to rolling and quality required conditions are constrict, Roll material of hot rolling finishing stand is changing Hi-Cr Roll to High Speed Steel [HSS] Roll. The problem of HSS Roll of roll force and strip scale defects are increasing in hot strip mill, So we have tested HSS Roll in hot rolling simulator as rolling condition, rolling speed, draft, hot oil concentration. To reduce roll force and prevent scale defects. We get some merit rolling force, rolling torque, roll wear reduction, roll and strip surface roughness and hot rolling critical oil concentration 0.4%. Finally we are going to investigate the effect of hot rolling oil of on rolling with HSS Roll.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.48-53
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• 1989

We attempt to achieve both high dynamic performance and maximal power efficiency by means of linear decoupling of rotor speed (or motor torque) and rotor flux. The induction motor with our controller possesses the input-output dynamic characteristics of a linear system such that the rotor speed (or motor torque) and the rotor flux are decoupled. The rotor speed (or motor torque) responses are not affected by abrupt changes in the rotor flux and vice versa. The rotor flux need not be measured but is estimated by the well-known flux simulator. The effect of large variation in the rotor resistance on the control performances is minimized by employing a parameter adaptation method. To illuminate the significance of our work. we present simulation and experimental results as well as mathematical performance analyses.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.4_2
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• pp.623-628
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• 2023

The purpose of this study was to evaluate the fracture strength and removal torque value (RTV) of a conventional angled abutment and a newly developed angled abutment (Beauty up abutment) with an angulated screw access hole. Each abutment was divided into a control group and an experimental group (n = 20, respectively). To measure the fracture strength, the abutment was connected to the internal hex implant with 30 Ncm torque, and a load was applied at 30 degree angle with cross-head speed of 1 mm/min using a universal testing machine according to the ISO 14801:2016 standard. To measure RTV, each abutment was fastened to the implant with 30 Ncm torque. Retightening was performed after 10 minutes, and initial RTV was measured with a digital torque gauge. After retightening, a load of 250 N was applied to the abutment at a 30 degree angle using a chewing simulator. After a total of 100,000 repeated loads, RTV was measured. Statistical analysis was performed using Wilcoxon signed rank test and Mann-Whitney U test (α = .05). The fracture strength of the experimental group was statistically significantly lower than that of the control group (P = .009). There was no significant difference between initial RTV and post-loading RTV between the experimental group and the control group (P = .753, P = .527, respectively), and cyclic loading did not significantly affect RTV in both groups (P = .078).

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.216-216
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• 2000

In this paper, we introduce a new roadway-departure prevention algorithm and the developed Hardware-in-the-Loop-Simulator (HiLS) for applying the new algorithm. A sliding-mode controller is used for lateral position control. And, the HiLS consists of real car elements, a micro-control board, and a self-aligning torque generator Finally from the display module, the perspective view and bird view of the animated vehicle can be seen simultaneously.

• Journal of information and communication convergence engineering
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• v.5 no.3
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• pp.223-228
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• 2007

This paper deals with the secondary excited induction generator applied to random wave input generation system. As it is preferred to stabilize the output voltage and frequency in the constant level, microcomputer controlled CSI connected to the secondary windings supplies the secondary current with slip frequency. For testing this method, the input torque simulator is constructed, according to the power flow analysis. The experimental and numerical results show the advantage of secondary excited induction generator system for the random input wave generation system.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.906-908
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• 2000

This paper presents dynamic modeling and simulation of induction motors. Equivalent circuit parameters measured by do test, no-load test and locked-rotor test were used as the input data for computer simulation. Operating characteristics of an induction motor were predicted by Matlab/simulink when changing load torque, opening and reclosing of phase a of the stator and three-phase fault at machine terminals.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.449-450
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• 2014

풍력 발전 시스템은 풍력 터빈이 바람에 의해 회전함으로써 발전이 된다. 실험실에서 풍력 발전 시스템을 연구하기 위해서는 바람이 하는 역할을 별도의 모터를 사용하여 회전시켜 주어야 하는데 본 논문에서는 유도전동기의 직접 토크 제어를 이용하여 풍속 데이터를 가지고 상응하는 토크의 지령치로 환산하여 풍력 에너지를 모델링 하였다. 이렇게 발전된 에너지를 최대의 효율로 전달하기 위해서는 MPPT기능이 수행되어야 하며 별도의 센서가 필요없는 Fuzzy MPPT를 수행하였다.