• Proceedings of the KIPE Conference
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• 2019.11a
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• pp.186-187
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• 2019

DC마이크로그리드에서 양방향 컨버터를 통한 계통과 배터리간의 전력교환은 계통연결 시 배터리를 충전시키고 계통분리 시 배터리를 통해 독립운전을 하는 양방향 동작의 형태로 수행된다. 이러한 운전모드 전환시 과도 오차를 줄이기 위해 무순단 절체 기능이 필요하다. 본 논문에서는 무순단 절체를 위해 전류 제어기를 공유함으로 발생하는 전압제어기 포화를 방지하는 하이브리드 안티와인드업 기법을 제안한다. DC마이크로그리드 시스템으로 구현해, 시뮬레이션을통해 기존방식과의 비교하고 제안한방식의 타당성을 검증하였다.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2684-2686
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• 2000

This paper describes a preliminary study on a modeling technique for control performance evaluation of asynchronous TMR(Triple Modular Redundancy) controller. Hybrid system modeling is applied to TMR controller performance evaluation and mixed logical dynamical system description is used to model the behavior of majority voter in the controller. Windup and bumpless transfer problems in redundancy controls are also mentioned.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.30-33
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• 2001

Advantages of switched reluctance motor(SRM) drives make it an attractive candidate for replacing adjustable speed ac and do drives in both industrial and consumer applications. Furthermore, a simple, low cost and robust SRM drive can be efficiently operatied ill the hostile environment of an automobile. In this paper, novel topology for fast response of various load is proposed. Proposed topology adapts anti-windup PI controller at increasing speed referense and activate braking mode at decreasing speed and forward load, Experiental results show that proposed topology have fast response charecteristics at increasing and decreasing speed reference.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.175-176
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• 2007

본 논문은 매입형 영구자석 동기 전동기의 준 식스스텝 운전(Quasi six-step operation)을 위한 약자속 제어에 대한 새로운 방법을 제안한다. 제안된 방법은 전향 경로(feedforward path)와 궤환 경로(feedback path)로 구성되고 전향 경로는 1차원 참조표로 구성되며 궤환 경로는 전류제어기 출력과 과변조에 의해 제한된 전압의 차이를 이용한다. 제안된 방법을 통해 약자속 제어와 안티 와인드업(anti-windup) 제어가 동시에 이루어질 수 있다. 또한 제한된 직류단 전압 조건에서 식스 스텝(six-step) 운전에서 낼 수 있는 전동기의 최대 토크에 가까이 출력 토크를 발생시키면서 전류 제어를 계속할 수 있는 준 식스 스텝 운전이 가능하다. 제안된 방법의 유효성을 컴퓨터 시뮬레이션과 실험의 결과를 통해 입증하였다.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.265-266
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• 2014

전기자동차에 적용되는 배터리 전압은 배터리의 용량, 크기, 중량 및 가격 등과 같은 사항에 의해 제한을 가진다. 따라서 전기자동차 구동을 위해 전류 제어를 수행할 경우 배터리 전압 제한에 따라 제어기의 포화가 발생할 수 있고, 이는 와인드업 현상을 야기한다. 와인드업 현상은 울렁거림 현상, 큰 오버슈트 및 느린 정착 시간과 같은 과도상태 응답 특성을 저하시키고 심각할 경우 시스템의 불안정을 초래한다. 자동차의 특성상 가 감속 및 정지, 출발과 같이 급변하는 기준 명령의 변화가 빈번하기 때문에 승차감 및 안정성에 있어 과도상태의 응답 특성이 매우 중요하다. 따라서 본 논문에서는 전기자동차용 유도전동기를 위한 반포화 적분-비례 제어기를 제안하고, 실험을 통해 제어 성능의 우수함을 보인다.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.54.4-54
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• 2001

This paper proposes an adaptive control scheme for an autopilot design of Relaxed-Static-Stability(RSS) Missiles with saturating actuator. The feedback linearization controller eliminates nonlinear terms in RSS missile dynamics and makes the entire system linear. But modeling errors, disturbances and the nonlinear mismatch due to input constraints exert a bad influence on the performance of the feedback linearization controller Thus, first, we derive a parametric affine uncertainty model with modeling errors and disturbances. Then an adaptive control law with anti-windup scheme is developed, where the bounds of uncertainties are estimated with adaptive laws. The proposed adaptive controller can remove the bad effects of uncertainties, of disturbances, and of saturating actuator ...

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.171-178
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• 1998

This paper proposes a new overmodulation strategy to give a better voltage utilization by tracking voltage vector along hexagon sides. This strategy enables the inverter to control both magnitude and angle of current. Therefore, the vector control using this strategy can lead to better output torque dynamics compared to the conventional slip frequency control with six-step voltage, which is widely used in the traction drive. In this strategy, the d-axis output voltage of a current controller to control the flux is conserved and the q-axis output voltage to control the torque is controlled to place the voltage vector on the hexagon boundary In case of overmodulation. The limited q-axis voltage is used for anti-windup of q-axis current controller. This paper also presents a new field weakening scheme which incorporate the proposed overmodulation strategy. In this scheme, the flux level is selected by both required current limit and the available maximum voltage along hexagon sides. The validity of the proposed overall scheme is confirmed by the computer simulations for a typical traction drive with a 210[㎾] induction motor.

• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.443-444
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• 2019

DC마이크로그리드에서, 양방향 컨버터를 통한 계통과 배터리와의 전력교환은 필수적으로 요구 된다. 일반적으로 계통이 연결 되었을 때 배터리를 충전시키고, 계통이 끊어 졌을 때는 배터리를 통해 계통에 전력을 공급하는 양방향 동작을 한다. 이러한 전력방향전환 과도상태를 줄이기 위해 무순단 절체 기능이 필요한데, 전류 제어기를 공유하는 방식의 경우 전압제어기의 포화가 발생하면 양방향 컨버터의 출력응답이 늦어지거나, 출력이 불안정해 진다. 이 문제를 해결하기 위해 양방향 컨버터의 대표적인 포화방지(Anti-windup)기법을 적용하여 성능을 비교하였다. 또한 PSIM 소프트웨어를 통해 DC마이크로그리드 시스템을 구현해 효과를 확인한다.

• Journal of the Ergonomics Society of Korea
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• v.27 no.2
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• pp.49-57
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• 2008

This study aims to investigate the effect of handle angles of pliers on performance, wrist motion and subjective rating of satisfaction. An experiment was conducted, in which handle angle of pliers was used as independent variable and 14 subjects participated. Based on the literature survey, plier handles angled at 0$^{\circ}$, 10$^{\circ}$, 20$^{\circ}$, 30$^{\circ}$ and 40$^{\circ}$ were adopted in the experiment. The subjects were instructed to bend iron plates by 90$^{\circ}$ and to cut wires as soon as possible. The results revealed that 1) handle angles of pliers have significant effect on wrist motion and satisfaction(p<0.0001); 2) handle angles of pliers did not affect performance of completing tasks irrespective of types of tasks done in the study; 3) in the initial stage of windup, plier with handle angled at 20$^{\circ}$ produced the least wrist motion of deviation in task of bending iron plates, while plier with handle angled at 40$^{\circ}$ did in task of cutting wires; 4) degree of satisfaction was maximized when handle of pliers was bent by 20$^{\circ}$ in both tasks. On the basis of the results, it is recommended that handle of pliers be bent by 20-30$^{\circ}$ for reducing musculoskeletal disorders related to pliers.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.10
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• pp.865-871
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• 2015

This study was conducted in order to develop a finger exoskeleton system using ionic polymer metal composites (IPMCs) as the actuator and sensor in a hybrid structure. To use the IPMC as an actuator producing large force, a first order transfer function was obtained using results from a block force for DC excitation that applied to two IPMCs of 20mm-width, 50mm-length, and 2.4mm thickness together. After which the validation of 200gf control with anti-windup PI controller was confirmed. A 5mm-width, 50mm-length, 0.6mm-thickness of IPMC was also modeled as a sensor for tip displacement. As a result, the IPMC sensor could been utilized as a trigger role for the actuator. Finally, an IPMC sensor and actuator were installed on the joint of a single DOF exoskeleton in the hybrid structure, and test for the control of 40gf of block force and predefined sequence of motion was performed.