• Journal of Advanced Marine Engineering and Technology
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• v.35 no.6
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• pp.820-828
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• 2011

Energy saving is one of the most important factors for profits in marine transportation. In order to reduce the specific fuel oil consumption, the ship's propulsion efficiency must be increased as much as possible. The propulsion efficiency depends upon a combination of propulsion engine and propeller that has better efficiency as lower rotational speed. As the engine has lower speed the variation of rotational torque become larger because of the longer delay time in fuel oil injection process. In this study, robust control theory is applied to the design of engine speed controllers which are sub-optimal $H_{\infty}$ controller, $H_{\infty}$ loop-shaping controller and ${\mu}$-synthesis controller considering robust stability and robust performance. And the validity of these three controllers is investigated through the results of computer simulation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.1
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• pp.89-93
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• 2000

Robust control for DC motor is needed according to the highest precision of industrial automation. However, when a motor control system has an effect of load disturbance, it is very difficult to guarantee the robustness of control system. Generally, it is known that sliding mode controller has robustness. But, after it is assumed that we known the disturbance uncertainty, sliding mode controller is designed. Thereafter, if we are not known th disturbance uncertainty then controller design is difficult. As a method solving this problem, in this paper, Expert sliding mode control method for motor control system is presented.The proposed controller can eliminate load disturbance effectively. The effectiveness of the control scheme is verified by simulation results.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.10
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• pp.1066-1074
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• 1990

In this paper, we attempt to control induction motors with high power efficiency as well as high dynamic performance by utilizing the recently developed theories : singular perturbation technique and noninteracting feedback control. Our controller consists of three subcontrollers` a saturation current controller, a decoupling controller, and a well-known flux simulator. The decoupling controller decouples rotor speed (or motor torque) and rotor flux linearly. Our controller does not need the rotor resistance that varies widely with the machine temperature. To illuminate the practical significance of our results, we present simulation and experimental results as well as mathematical performance analysis.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.412-413
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• 2018

고성능 트레드밀 시스템은 운동부하에 따른 큰 맥동부하 특성을 가지며 저속에서도 안정적인 제어 성능이 요구된다. 본 논문에서는 기존에 연구된 유도전동기 센서리스 제어 알고리즘을 검토하여 저속에서 부하의 변화에 강인한 특성을 갖는 알고리즘에 대하여 논하고 이를 트레드밀 시스템에 적용한 결과에 대하여 기술한다. 슬립제어기반의 속도제어기를 구성하였으며 벡터제어기반의 슬립연산 알고리즘을 도입하여 90rpm의 저속에서도 부하변동에 강인하고 안정적인 속도제어가 가능한 트레드밀 제어시스템을 구축하였다. 연구결과는 PSIM 시뮬레이션을 통하여 검증하였다.

• The Transactions of the Korean Institute of Power Electronics
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• v.15 no.5
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• pp.343-351
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• 2010

This paper proposes a new fuzzy speed controller based on the Takagi-Sugeno fuzzy method to achieve a robust speed control of a permanent magnet synchronous motor (PMSM). The proposed controller requires the information of the load torque, so the second-order load torque observer is used to estimate it. The LMI condition is derived for the existence of the proposed fuzzy speed controller, and the gains of the controller are provided. It is proven that the augmented control system including the fuzzy speed controller and the load torque observer is exponentially stable. To evaluate the performance of the proposed fuzzy speed controller, the simulation and experimental results are presented under motor parameter variations. Finally, it is clearly verified that the proposed control method can accurately control the speed of a permanent magnet synchronous motor.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.333-335
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• 2006

본 논문은 영구자석 교류 전동기의 센서리스 위치 오차 최소화 제어 방법에 관한 것으로, 회전자의 위치오차가 최소화 하도록 회전자 속도 추정 gain을 자동으로 조정함으로써 회전자의 속도 및 위치에 대한 오차를 최소화하기 위한 방법이다. 본 논문의 구성은 회전자 위치 오차를 최소화하기 위한 제어기와 이를 회전자 속도 게인으로 활용하는 적용 대상으로 구성 되어 있다. 이는 모터의 온도 및 운전 환경에 따른 parameter의 변동에 강인하도록 제어기의 게인을 자동 설정하며 회전자의 오차를 최소화 하도록 하는 제어기를 제안한다. 또한 본 논문에서 제한하는 알고리즘을 검증하기 위하여 시뮬레이션 하였다.

• The Transactions of the Korean Institute of Power Electronics
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• v.16 no.1
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• pp.44-49
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• 2011

This paper proposes a robust digital speed regulator for a surface-mounted permanent magnet synchronous motor(SPMSM). The proposed speed controller uses a simple digital load disturbance resistance scheme which does not require a load torque observer, so it can be easily and simply implemented without degrading the control performance. To validate the effectiveness of the proposed control algorithm, experimental results as well as simulation results are shown under motor parameter variations using a prototype SPMSM driving system. Finally, it was confirmed that the proposed method can precisely regulate the speed of the SPMSM.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.1
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• pp.150-156
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• 2001

This paper proposed a speed estimator using MRAC(Model Reference Adaptive Control) for sensorless vector control. It is robust for parameter variation or disturbance and the estimated speed is used as feedback in a vector control system. Experiment is presented to confirm the theoretical analysis.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.1
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• pp.1-6
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• 2008

In this paper, we present the robust fuzzy algorithm for variable speed control of wind turbines. Generally, the plants of wind turbines are consisted of complex nonlinearities, and the parameters of variable speed of wind turbines are represented as uncertain terms. For solving these complexity, we propose the robust fuzzy algorithm. At first, the exact fuzzy modeling are performed for variable speed of wind turbines. Next, we design the fuzzy controller for reanalyzed T-S fuzzy model of the wind turbines, then, we prove the stability of the plant through the Lyapunov stability theorem. At last, an example is included for visualizing the efficiency of the proposed technique.

• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.3
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• pp.215-220
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• 2000

본 논문에서는 SRM운전에서 맥동토오크와 부하토오크의 변화로 인한 속도변경을 줄이기 위해 동적 도통각 제어 원리를 이용한 PLL(Phase Locked Loop) 속도제어 방식을 채택하였다. SRM은 많은 장점을 가지고 있으나 토오크리플에 따른 속도변동으로 정밀한 속도제어에 어려움이 있다. SRM 구동 시스템에 PLL을 적용한 결과 전동기는 강인한 정속도 운전을 할 수 있으며, 또한 운전속도에 따라 선행각을 조정함으로서 고효율 구동을 할 수 있었다. 구성된 시스템은 운전속도와 부하의 변화에 따라 선행각이 증가함으로써 뛰어난 동적 속도제어 특성을 갖고 있으며, 인버터 인가전압을 제어하는 선행각을 조정함으로서 일정부하 영역에서 높은 효율특성을 가진다. SRM 구동 시스템의 PLL 속도제어와 고효율 구동을 위한 도통각제어를 위해 TMS320F240 DSP를 사용함으로서 디지털 제어기의 유연성과 소형화를 꾀하였다.