• Transactions of the Society of Information Storage Systems
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• v.3 no.2
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• pp.73-80
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• 2007

Atomic Force Microscopy (AFM)방식을 이용한 Scanning probe Data Storage (SDS) 시스템은 array cantilever 를 이용하여 나노 단위로 데이터 읽기, 쓰기를 하는 시스템이다. 따라서 미디어가 있는 stage 의 x 축과 y 축 및 두 축간 coupling 을 고려한 제어기 설계가 요구된다. 본 논문은 SDS 시스템의 축간 coupling 을 고려하지 않은 기존의 제안된 LQG 에 PI 를 추가한 제어기 구조를 사용한다. 두 축간 coupling 공진의 영향을 최소화 하기 위해 convex optimization 으로 설계된 최적의 position profile를 기준 입력신호로 사용한다. 제안된 제어기를 SDS 시스템에 적용하여 모의실험을 하고 그 결과 position profile 로 인해 각 축간 coupling 공진 영향이 감소하여 tracking performance 가 기존의 LQG 제어기 보다 향상된 것을 확인한다.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.2015-2017
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• 1998

This paper deals with the design of a field oriented control system model for the high performance induction motor using Matlab with Simulink. The proposed control system model, which is not used the speed and flux sensor, contains IM model, Tranformation, Decoupling, FFOC(Field Flux Orientation Controller), Torque calculator and PI Controller to control speed, torque. Results present the stator and rotor flux phasor trajectory, the startup and transient response of speed, torque and stator current with field oriented control and the response to changes in reference speed with no load. This paper shows that the propose control system is more robust than other vector control system, and suggest the enchanced model, using Matlab with Simulink for the high performance in induction motor control.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.9-15
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• 2008

In this paper, we suggest PI control with a predictive controller to progress both energy saving and coefficient of performance(COP) in a variable speed refrigeration system. The capacity and superheat are controlled simultaneously and independently by an inverter and an electronic expansion valve respectively for saving energy and improving COP in the system. The refrigeration system has long dead time in superheat inherently. The dead time makes the system difficult to achieve the satisfactory quick control response, especially superheat control response. In order to solve this problem, we designed a predictive controller based on PI control to progress superheat control performance. The control performance was investigated through some experiments to verify the effectiveness of the predictive controller.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.222-224
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• 2008

본 논문에서는 3상 VSI의 CVCF 제어를 위해 폐루프 비간섭 DQ 제어기 설계를 제안한다. DQ 제어기를 설계하기위해서 두 개의 간섭항을 폐루프 분리를 통하여 해석적인 PID 제어기를 설계한다. 제안한 PID 제어기는 시간응답을 만족하도록 설계하여 시뮬레이션을 통해 검증한다.

• Journal of the Korean Institute of Intelligent Systems
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• v.10 no.3
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• pp.211-217
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• 2000

A main contribution of this paper is the development of a Hopfield network-based algorithm for the fault diagnosis of the actuators in linear system with uncertainties. An unknown input decoupling approach is introduced to the design of an adaptive observer so that the observer is insensitive to uncertainties. As a result, the output observation error equation does not depend on the effect of uncertainties. Simultaneous energy minimization by the Hopfield network is used to minimize the least mean square of errors of errors of estimates of output variables. The Hopfield network provides an estimate of the gains of the actuators. When the system dynamics changes, identified gains go through a transient period and this period is used to detect faults. The proposed scheme is demonstrated through its application to a simulated second-order system.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.326-327
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• 2018

본 논문에서는 단상전력변환시스템에서 발생하는 고유의 2차 리플 전력 문제를 해결하고 dc 캐패시터의 저감을 위한 능동 전력 디커플링 회로의 설계방법을 제시한다. 일반적인 수동 전력 디커플링 방법, 벅-타입 방법 및 커패시터 분할 타입 방법의 능동 전력 디커플링 회로들에서 필요한 최소의 커패시턴스를 계산하는 방법을 제시하고, 같은 조건에서 리플 전력 디커플링 성능을 분석한다. 도출된 최소한의 커패시턴스를 적용한 디커플링 회로의 성능은 MATLAB 시뮬레이션 결과를 통해 비교 분석하였다.

• Proceedings of the KIPE Conference
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• 2019.11a
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• pp.61-63
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• 2019

본 논문은 3.3 kW 전기자동차용 탑재형 충전기의 전력 밀도 향상을 위해 디커플링 기법이 적용된 PFC (Power factor correction) 회로의 초치적 설계 방안을 제안한다. 최적 설계를 위하여 buck-boost 컨버터 형태의 디커플링 회로 동작 원리를 기반으로 스위칭 주파수에 따른 PFC 회로의 손실과 부피를 분석하고 최적 설계점을 도출한다.

• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.460-462
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• 1998

In this study, we deal with a multivariable system which its input and output are coupled. This study presents a method for designing a controller which allows a coupled system to be transformed to a decoupled system in a standard model adopting 2DOF controller. And Wiener-Hopf($H_2$) approach is used so that the designed controller can minimize given cost function.

• JSTS:Journal of Semiconductor Technology and Science
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• v.13 no.2
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• pp.114-126
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• 2013

In this paper, we present a set of methodologies to model the electromagnetic susceptibility (EMS) testing of I/O buffers for mobile system memory based on the bulk current injection (BCI) method. An efficient equivalent circuit model is developed for the current injection probe, line impedance stabilization network (LISN), printed circuit board (PCB), and package. The simulation results show good correlation with the measurements and thus, the work presented here will enable electromagnetic susceptibility analysis at the integrated circuit (IC) design stage.

• Journal of Power Electronics
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• v.11 no.5
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• pp.713-718
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• 2011

This paper presents an online voltage disturbance estimator to achieve precise torque control of IPMSMs over a high speed operating region. The proposed design has a type of state-filter based on a Luenburger-style closed loop stator current vector observer. Utilizing the frequency response plot (FRF) approach, the estimation accuracy and the parameter sensitivities are analyzed. Accurate torque control and improved efficiency are provided with the decoupling of the effect of the parameter variations. The feasibility of the presented idea is verified by laboratory experiments.