• 전력전자학회논문지
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• 제17권1호
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• pp.57-66
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• 2012

This paper proposes a performance improvement of grid-connected inverter system using sliding-mode based direct power control with a variable gain. The proposed control method determine variable gain of PI controller by using modeling at direct power control (DPC) applied to space vector modulation method. Also, this method use sliding-mode control to maintain excellent dynamic response of character of direct power control (DPC). The validity of the proposed algorithm are verified by simulations and experiments.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.1058-1059
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• 2015

This paper describes a low-voltage ride-through method for the permanent magnet synchronous generator (PMSG) wind turbine system at a grid fault. The generator side converter regulates the DC link voltage instead of the grid side converter by storing the surplus active power in the rotor inertia during grid fault by the sliding mode controller. The grid side converter controls the grid active power keeping a maximum power point tracking. Simulation results for small scale PMSG wind turbine verify the efficiency of the control method.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.67.2-67
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• 2001

In the adaptive fuzzy sliding mode control, from a set of fuzzy IF-THEN rules adaptive fuzzy sliding mode control whose parameters are adjusted on-line according to some adaptation laws is constructed for the purpose of controlling the plant to track a desired trajectory. Most of the research works in nonlinear controller design using fuzzy systems consider the affine system with fixed grid-rule structure based on system state availability. The fixed grid-rule structure makes the order of the controller big unnecessarily, hence the on-line fuzzy rule structure and fuzzy observer based adaptive fuzzy sliding mode controller is proposed to solve system state availability problems. Therefore adaptive laws of fuzzy parameters ...

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.2308-2310
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• 2001

In the adaptive fuzzy sliding mode control, from a set of a fuzzy IF-THEN rules adaptive fuzzy sliding mode control whose parameters are adjusted on-line according to some adaptation laws is constructed for the purpose of controlling the plant to track a desired trajectory. Most of the research works in nonlinear controller design using fuzzy systems consider the affine system with fixed grid-rule structure based on system state availability. The fixed grid-rule structure makes the order of the controller big unnecessarily, hence the on-line fuzzy rule structure and fuzzy observer based adaptive fuzzy sliding mode controller is proposed to solve system state availability problems. Therefore, adaptive laws of fuzzy parameters for state observer and fuzzy rule structure are established implying whole system stability in the sense of Lyapunov.

• 전력전자학회논문지
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• 제16권4호
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• pp.396-404
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• 2011

본 논문은 불평형 전원사고 발생 시 계통연계형 풍력발전 시스템의 성능 개선을 위한 슬라이딩모드 기반의 직접전력제어기법을 제안한다. 제안하는 제어기법은 전류의 좌표변환 없이 시스템의 유, 무효 전력을 직접 제어함으로써 계통사고 시 빠른 응답특성을 가지고 별도의 동기위상각 정보를 필요로 하지 않으며, 불평형 사고 시 계통주파수의 2배에 해당하는 전력 리플이 발생하지 않으므로 계통연계형 풍력발전 시스템 제어에 적합하다. 시뮬레이션 및 실험 결과를 통해 제안하는 제어기법의 타당성과 강인성을 확인한다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.340-342
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• 2005

A sliding mode controller for the grid-connected photovoltaic system has been presented. This controller is constructed from the time-varying sliding surface In order to control the sinusoidal inductor current and solar array power simultaneously. The proposed controller can achieve the tight regulation of current and power under the parameter variation environment.

• Journal of Power Electronics
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• 제17권4호
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• pp.1048-1057
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• 2017

An indirect matrix converter (IMC) is a modern power generation system that enables a direct ac/ac conversion without the need for any bulky and limited lifetime electrolytic capacitor. This system also allows four-quadrant operation, generation of sinusoidal output voltage waveforms with variable frequency and amplitude, and control of input power factor. This study proposes a pulse-width modulation-based sliding-mode controller to achieve unity input-power factor operation of the IMC independently of the active power exchanged with the grid, as well as a fast dynamic response. The designed equivalent control law determines, at each sampling period, the appropriate q-axis component of the modulated input current to be injected into the grid through the LC input filter. An integral term of the error is included in the expression of the sliding surface to increase the accuracy of the control method. A double space vector modulation method is used to synthesize the direction of the space vector of the input currents as required by the sliding-mode controller and the space vectors of the target output voltages. Simulation and experimental results are provided to show the effectiveness and evaluate the performance of the proposed control method.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.284-284
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• 2000

In adaptive fuzzy control systems. fuzzy systems are used to approximate the unknown plant nonlinearities. Until now. most of the papers in the field of controller design for nonlinear system using fuzzy systems considers the affine system with fixed grid-rule structure based on system state availability. This paper considers observer-based nonlinear controller and dynamic fuzzy rule structure. Adaptive laws for fuzzy parameters for state observer and fuzzy rule structure are established so that the whole system is stable in the sense of Lyapunov.

• 전력전자학회논문지
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• 제10권4호
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• pp.411-419
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• 2005

본 논문에서는 계통연계형 태양광 발전시스템의 태양전지 전류 추정을 위한 슬라이딩 모드 관측기 설계 방법이 제시되었다. 태양전지 전류 추정 정보는 슬라이딩 모드 관측기에서 얻어지고, 기준전압을 갱신하기 위한 최대전력 추적기의 입력정보로 사용되어 진다. 계통연계형 인버터의 입력 커패시턴스 값은 규정치의 50[$\%$] 정도까지 바뀔 수 있으며, 선형 관측기는 파라미터 변화나 외란이 존재하는 조건에서는 정확한 상태값을 추정할 수 없다. 슬라이딩 모드 관측기의 구조는 간단하지만, 파라미터 변화나 외란에서도 슬라이딩 모드 관측기는 강인한 추종능력을 보여주고 있다. 본 논문에서는 등가 입력조건을 이용한 슬라이딩 모드 관측기를 설계하는 방법이 제시되고, 제시된 관측기의 수렴조건에 대해 서술하였다. 수학적인 모델링과 실험결과로서 제안한 방법의 타당성을 입증하였다.

• Journal of Electrical Engineering and Technology
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• 제12권4호
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• pp.1340-1347
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• 2017

Utilization of Electric Vehicles (EVs) have been growing popularity in recent years due to increment in fuel price and lack of natural resources. Random unexpected charging by home EV charger in distribution is predicted in the future. The power quality problems such as fluctuation of power factor in a residential distribution network was explored with random EV chargers. This paper proposes a high-performance nonlinear sliding mode controller (SMC) for an EV charging system to compensate voltage distortions and to enhance the power factor against the unbalanced EV chargers. For the verification of the proposed scheme, MATLAB-Simulink simulations are performed on 22.9-kV grid. The results show that the proposed scheme can improve the power factor of a smart grid due to the EV chargers on the grid.