• 전력전자학회논문지
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• 제22권2호
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• pp.126-133
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• 2017

The conventional battery charger requires two separate voltage and current compensators to achieve constant current and constant-current-charging profile. This compensator configuration leads to an inevitable transient response during the mode change between the constant current and the constant voltage operation. Futhermore, a tedious and complicated design process is required to consider a widely changing battery voltage and the nonlinear electrical properties of Li-ion battery. This study proposes a single integrated voltage-current compensator of the LLC resonant converter for Li-ion battery charger applications to overcome the aforementioned drawbacks. The proposed compensator is designed to provide a smooth and reliable performance during the entire charging process while providing the reduced design efforts and seamless mode transient response. Several experimental results based on a 300 W prototype converter and its theoretical analysis are provided to verify the effectiveness of the proposed compensator.

• 한국융합학회논문지
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• 제8권12호
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• pp.291-298
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• 2017

최근 차량내부에서는 운전과 직접적인 관련이 적은 다양한 편의장치들이 도입되고 있으며, 이러한 장치들의 조작환경을 하나로 통합하려는 노력이 시도되고 있다. 본 논문은 자동차 내의 다양한 편의장치에 대한 통합 조작환경을 구축하기 위해 자기유변유체(magnetorheological fluid; MR 유체)를 이용한 햅틱장치를 제안하고자 한다. 이를 위해 먼저 차량 편의 조작장치들이 갖는 회전과 상하 수직 운동을 동시에 구현할 수 있는 메커니즘을 고안하고 햅틱 기능을 부여하기 위해 MR 유체를 도입함으로써 하나의 장치로 다기능 조작이 가능한 햅틱 장치를 고안한다. 장치에서 발생하는 반향력에 대한 모델링에 근거하여 MR 햅틱 장치의 자료를 설계하고 시작품을 제작한다. 그리고 완성된 장치의 회전 및 수직 운동에 대한 응답 성능시험을 수행하여 제안된 모델을 검정한다. 또한 힘 반향 성능을 구현하기 위해 장치의 반향력 모델을 이용한 역모델 보상기(inverse model compensator)를 설계한다. 마지막으로 실제 자동차의 여러 편의 기능의 작동과정을 고려하여 햅틱 반향력 맵을 구축하고 제어기와 연동하여 제작된 햅틱 장치의 힘반향(force-feedback) 제어 성능을 평가한다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 추계학술대회 논문집
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• pp.415-420
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• 2009

This paper presents a position tracking control of a flexible beam using the piezoelectric actuator. This is achieved by implementing both feedforward hysteretic compensator of the actuator and PID feedback controller. The Preisach model is adopted to develop the feedforward hysteretic compensator. In the design of the compensator, estimated displacement of the piezoceramic actuator is used on the basis of the limiting triangle database that results from collecting data of the main reversal curve and the first order ascending curves. Experimental implementation is conducted for position tracking control and performance comparison is made between a PID feedback controller without considering the effect of hysteresis, and a PID feedback controller integrated with the feedforward hysteretic compensator.

• 대한전자공학회논문지SD
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• 제45권6호
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• pp.37-42
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• 2008

H.264/AVC 복호기에서는 인트라 예측기 뿐만 아니라 움직임 보상기, 디블럭킹 필터 등 각 IP들이 복호화를 위한 참조 영상 값들을 필요로 한다. 이들 IP들은 참조 영상을 읽어들이기 위하여 외부 메모리에 빈번하게 접근하는데, 이때문에 시스템 동작 속도도 낮아지고 전력 소모도 증가한다. 본 논문에서는 공통적이고 반복적인 블록의 재사용을 통하여 연산량을 줄이고 전력 소모 및 메모리 대역폭을 최소화하도록 외부 메모리를 사용하지 않는 움직임 보상기와 연계한 인트라 예측기를 제안하였다. 제안된 인트라 예측기는 기존에 비해 $45%\;{\sim}\;75%$ 가량 사이클 수를 감소시켰다.

• Journal of Power Electronics
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• 제17권3호
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• pp.686-694
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• 2017

Due to the wide use of electronic products, digitally controlled DC-DC converters are attracting more and more attention in recent years. However, digital control strategies may introduce undesirable Limit Cycle Oscillation (LCO) due to quantization effects in the Analog-to-Digital Converter (ADC) and Digital Pulse Width Modulator (DPWM). This results in decreases in the quality of the output voltage and the efficiency of the system. Meanwhile, even if the resolution of the DPWM is finer than that of the ADC, LCO may still exist due to improper parameters of the digital compensator. In order to discover how LCO is generated, the state space averaging model is applied to derive equilibrium equations of a digital PID controlled DC-DC converter in this paper. Furthermore, the influences of the parameters of the digital PID compensator, and the resolutions of the ADC and DPWM on LCO are studied in detail. The amplitude together with the period of LCO as well as the corresponding PID parameters are obtained. Finally, MATLAB/Simulink simulations and FPGA verifications are carried out and no-LCO conditions are obtained.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.73-76
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• 1996

This paper presents a dynamical anti-reset windup (ARW) compensation method for saturating control systems with multiple controllers and/or multiloop configuration. By regarding the difference of the controller states in the absence and presence of saturating actuators as an objective function, the dynamical compensator which minimize the objective function are derived in an integrated fashion. The proposed dynamical compensator is a closed form of the plant and controller parameters. The proposed method guarantees total stability of resulting system. An illustrative example is given to show the effectiveness of the proposed method.

• 한국소음진동공학회논문집
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• 제20권2호
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• pp.129-137
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• 2010

이 논문에서는 압전작동기를 이용하여 유연 보 구조물의 위치추적제어를 실험적으로 고찰하였다. 작동기의 히스테리시스 특성을 보상하기 위한 앞먹임 보상기와 PID 되먹임 제어기를 함께 구성하여 정밀한 위치 추적제어를 수행할 수 있도록 하였다. 히스테리시스 보상기는 압전작동기의 예측 변위를 바탕으로 한 프라이작 모델을 사용하여 구성하였다. 히스테리시스 보상기의 유무에 따른 PID 되먹임 제어의 성능을 조화가진과 랜덤 가진 실험을 통하여 평가하였으며, 보상기와 되먹임 제어기를 함께 사용하였을 때, 우수한 위치추적제어 성능을 가지는 것을 확인하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2014년도 추계학술대회 논문집
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• pp.75-76
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• 2014

This study deals with a isolation type MIC(Module Integrated Converter) for AC module with advantages such as DC Wireless, freely selectable installation capacity, minimized shadow effect etc. In this paper, MIC circuit with the function which can remove the ripple voltage of PV module and give the discharging path for charged energy in leakage inductance of isolation transformer. The validity of proposed circuir is verified by the simulation with PSIM.

• 전자공학회논문지B
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• 제33B권7호
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• pp.21-31
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• 1996

An intelligent integrated control system is designed for the active steering and the left/right traction force distribution control of electric vehicles, where input-output linearization is employed. Also, a fuzzy-rule-based cornering force estimator is suggested to avoid using an uncertain highly nonlinear expression, and a neural network compensator is additively utilized for the estimator to correctly find cornering forece. With these techniques, the proposed control system is shown by simulation results to be robust against drastic change of the external environments such as road conditions.

• Journal of Power Electronics
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• 제17권2호
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• pp.522-532
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• 2017

This paper presents a novel integrated structure for a cascaded distribution static compensator (D-STATCOM) and distribution transformer for medium-voltage reactive power compensation. The cascaded multilevel converter is connected to a system via a group of special designed taps on the primary windings of the Dyn11 connection distribution transformer. The three-phase winding taps are symmetrically arranged and the connection point voltage can be decreased to half of the line-to-line voltage at most. Thus, the voltage stress for the D-STATCOM is reduced and a compromise between the voltage rating and the current rating can be achieved. The spare capacity of the distribution transformer can also be fully used. The working mechanism is explained in detail and a modified control strategy is proposed for reactive power compensation. Finally, both simulation and scaled-down prototype experimental results are provided to verify the feasibility and effectiveness of the proposed connection structure and control strategy.