• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.1035-1040
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• 1989

This paper describes first Boxes algorithm as a good method to generate the pulse patterns for a pulse width modulated inverter which has a good characteristics and simple to excute. Second we present the motor analysis fed by P.W.M. inverter in steady-state operation. In this analysis we improve the MRF ( Multiple Reference Frames ) to can be easy apply to analyse all the induction motor parameters. Finally we presented all the results obtained for a 3-phase induction motor.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.35T no.1
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• pp.90-98
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• 1998

This paper is to describe the improved vector control which can control the induction motor robustly in low speed. When the induction motor is drived with low speed, below 10 percent of the rated speed, an algorithm which can compensate the error of unit vector angle generated by the harmonics is proposed. Another algorithm which can be tuned to the rotor time constant so that nay be robust to the rotor parameter change in low speed and transient state was proposed. The ripple of flux and torque was reduced by the proposed vector control and then the stable output characteristics was obtained in low speed. When the input and output is sinusoidal, the proposed vector control, the direct vector control and the indirect vector control were analyzed and compared in the low speed characteristics. And each control characteristics is compared and analyzed in state of containing harmonics. The estimation and tunning performance of rotor time constant is confirmed with simulation. The whole control system is implemented by real hardware and experimented to compare the proposed vector control with the direct vector control. As a result of the experiment with two control methods in low speed, the torque ripple of the proposed vector control is improved by 45 percent than the direct vector control. And it is confirmed that the flux current ripple is reduced in 0.2 p.u. and torque current ripple is reduced in 0.6 p.u. It is confirmed that the rotor time constant by the estimation and the tunning algorithm is tunned by the real rotor time constant. Finally, it was confirmed that the validity and robustness for the proposed vector control in low speed existed.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.437-438
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• 2017

본 연구는 독립 운전 모드의 P+MR 기반의 전압제어기의 계통 동기화 방식을 조사한다. 계통 복전 후 계통과의 재연결을 위한 계통 동기화가 고정자 좌표계하에서 제어가 수행되는 경우, 독립운전하에서 정전압, 정주파수를 가지는 교류 지령 전압은 계통 전압으로 대체되는데 이 부분에서 고정자 좌표계 제어하의 현재 출력 전압과 계통 전압의 위상 차이에 기인하여 상당한 전압 오차가 발생할 여지가 있고 이러한 전압 오차 발생은 심각한 전압 과도 상태를 야기할 수 있게 된다. 추가적으로, 인버터의 출력 단에 연결된 부하가 비선형 부하라면 부하에서 생성되는 고조파에 기인하여 위에 언급된 전압 과도 상태가 더욱 심각해질 수 있다. 본 논문에서는 위에 언급된 문제를 해결하기 위한 대책으로 독립 운전 모드하에서의 전압 제어를 위해 사용되는 P+MR 제어 기반의 비선형 부하를 고려한 매끄러운 계통 동기화 방식이 제안되었다. 제안된 매끄러운 계통 동기화 방식은 실험 결과를 통해 검증된다.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.2
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• pp.215-223
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• 2006

The internal corrosion of water distribution systems is the main cause for the problem of the public health threat as well as water leakage in the damaged pipeline, red water, and odor and taste of the tap water. This study was examined the effect of chemicals used for pH and alkalinity control and corrosion inhibitors for producing the optimal corrosion control method. Corrosion study at different pH and alkalinity indicated that these control using alkaline chemicals was effective in corrosion rate, Fe release reduction, but examined to be increased in turbidity and corrosion-by-products(TTHMs) problems. The turbidity was slightly increased, requiring caution in controlling corrosion with $Ca(OH)_2$. At pH 9.0, TTHMs concentration is increased two times corn pared with non-control of pH. Using the pipe which had experienced 28 years of exposure, iron release was decreased with the corrosion inhibitor. Consequently, pH, Alkalinity control method using alkaline chemicals must be complemented by corrosion inhibitor application for efficient corrosion control.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.11
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• pp.791-800
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• 2022

The number and locations of force generators and their force directions of Active Vibration Control System(AVCS) are important to maximize the airframe vibration reduction performance of helicopters. The present AVCS simulation using an exhaustive test method attempts to determine the best number and locations of force generators and their force directions for maximization of the airframe vibration reduction performance of UH-60A helicopter at 158 knots. The 4P hub vibratory loads of the UH-60A helicopter are calculated using DYMORE II, a nonlinear multibody dynamics analysis code, and MSC.NASTRAN is used to predict the vibration responses of the UH-60A airframe. The AVCS framework with an exhaustive test method is constructed using MATLAB Simulink. As a result, when applying AVCS with the optimal combination of the force generators, the 4P airframe vibration responses of UH-60A helicopter are reduced by from 19.35% to 98.07% compared to the baseline results without AVCS.

• Journal of the Institute of Convergence Signal Processing
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• v.13 no.1
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• pp.56-62
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• 2012

This paper presents design and implementation of the speed controller for DC motor system using Embeded Target for TI C2000 DSP library in Matlab/Simulink is introduced. Speed controller are easily design and implemented by using the Matlab/Simulink program. Feedback of motor speed is processed through eZdsp F2812 AID converter using encoder and pulse meter as speed sensor. Real-time program of controller is drawn using Simulink and converted program code for speed control of P control, PID control and parameter estimation base adaptive control is downloaded into the TI eZdsp 2812 board. Experiments were carried out to examine validity of speed response for implemented controllers. And even if controlled plant becomes alteration studied controller design and implementation easily method.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.133-134
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• 2013

현재 LS산전과 한국전력공사의 공동 개발을 통하여 60MW급 ${\pm}80kV$ 전류형 HVDC(High Voltage Direct Current) Transmission System 내 알고리즘 국산화 개발을 진행하고 있다. 제어 알고리즘 여러 레벨(AC Yard Control, Master Control, Pole Control, Phase Control)에서 운전하기 전 여러 고려사항 중 DC Yard 내 DC Switch의 투입/개방의 조건이 있다. 본 논문에서는 이러한 DC Line에 DC Switch의 상태를 효율적으로 제어하는 방법에 대해 소개하고자 한다.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.3
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• pp.221-225
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• 2008

This paper presents a self-tuning controller for pressurized water reactor (P.W.R.). This self-tuning controller includes two substantial steps, such as parameter identification and control-law building in each cycle. Extended least square algorithm is used for parameter identification, Kalman filter is used for state estimation, and discrete Riccati equation is used for optimal control. Effectiveness of this algorithm is shown through computer simulation and sensitivity analysis.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.10
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• pp.2129-2136
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• 2012

With the increased demand of ubiquitous home services, intelligent robots have wide attentions. This kind of robots offer various services through middleware components which can connect with remote servers. In this paper we present an UPnP(Universal Plug and Play) based open-source software framework which makes control the robots remotely. This UPnP architecture for home networking can provide various communication methodologies like command control, eventing, presentation with web services and so on. This paper shows successful implementation results on two real platforms.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10b
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• pp.1864-1866
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• 1991

We present a parameter estimator which operates in the domain of iteration sequence. The scheme can be applied to identify unknown algebraic system whose uncertainty is parametric.