• Journal of Power Electronics
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• 제17권1호
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• pp.232-241
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• 2017

Advanced control algorithms must be used to make wind power generation truly cost effective and reliable. In this study, we develop a new and simple control scheme that employs model predictive control (MPC), which is used in permanent magnet synchronous generators and grid-connected inverters. The proposed control law is based on two points, namely, MPC-based torque-current control loop is used for the generator-side converter to reach the maximum power point of the wind turbine, and MPC-based direct power control loop is used for the grid-side converter to satisfy the grid code and help improve system stability. Moreover, a simple prediction scheme is developed for the direct-drive wind energy conversion system (WECS) to reduce the computation burden for real-time applications. A small-scale WECS laboratory prototype is built and evaluated to verify the validity of the developed control methods. Acceptable results are obtained from the real-time implementation of the proposed MPC methods for WECS.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 추계학술대회
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• pp.267-270
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• 2014

본 논문에서는 진동에너지 수확을 위한 CMOS 인터페이스 회로를 설계하였다. 제안된 회로는 AC-DC 변환기와 DC-DC 부스트 변환기로 구성된다. AC-DC 변환기는 진동소자(PZT)에서 출력되는 AC 신호를 DC 신호로 변환해주는 역할을 하며, DC-DC 부스트 변환기는 AC-DC 변환기에서 출력된 신호를 원하는 값으로 승압 및 안정화 시키는 역할을 한다. AC-DC 변환기는 효율 특성이 좋은 능동 다이오드를 이용한 전파정류기를 사용하였으며, DC-DC 부스트 변환기는 제어 회로가 간단한 쇼트키 다이오드를 사용한 구조를 이용하였다. 또한 진동소자로부터 최대전력을 수확하기 위한 MPPT(Maximum Power Point Tracking) 기능을 적용하였다. 제안된 회로는 0.35um CMOS 공정으로 설계되었으며, 설계된 칩의 면적은 $530um{\times}325um$이다. 설계된 회로의 성능을 검증한 결과 AC-DC 변환기와 DC-DC 부스트 변환기의 최대 효율은 각각 97.7%와 89.2%이며, 전체회로의 최대 효율은 87.2%이다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
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• pp.204-207
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• 2003

PV model is presented based on the shockley diode equation. The simple model has a photo-current source, an single diode junction and a series resistance and includes temperature dependences. An accurate PV module electrical model is presented, matching with boost converter MPPT strategy and demonstrated in Matlab for a typical general purpose solar cell. Given solar insolation and temperature, the model returns current vector and MPP.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2009년도 추계학술대회 논문집
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• pp.367-370
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• 2009

This paper proposes a novel maximum power point tracking(MPPT) control algorithm considering insolation to improve efficiency of PV system. The proposed algorithm is composed perturb and observe(P&O) method and constant voltage(CV) method. P&O method is simple to realize and CV method is possible to tracking MPP with low insolation. Response characteristics of proposed algorithm is compared to conventional P&O method with insolation variation. This paper proves the validity of proposed algorithm through the analysis result.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.341-348
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• 2003

Photovoltaic systems normally use a maximum power point tracking (MPPT) technique ta continuously deliver the highest possible power to the load when variations in the insolation and temperature occur. A simple method of tracking the maximum power points (MPPs) and forcing the boost converter system to operate close to these points is presented through deriving small-signal model and transfer function of boost converter. This paper aims at modeling boost converter including equivalent series resistance of input reservoir capacitor by state-space-averaging method and PWM switch model with properly designed controller for maximum photovoltaic power tracking control.

• 제어로봇시스템학회논문지
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• 제22권5호
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• pp.315-319
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• 2016

This paper proposes a simple adaptive sliding mode control algorithm for controlling a permanent magnet synchronous generator (PMSG) of a MW-class direct-driven wind turbine system. The proposed adaptive sliding mode controller does not require accurate knowledge of the PMSG parameter or turbine torque values. The proposed controller can accurately track the reference angular speed computed by the maximum power point tracking(MPPT) algorithm. Finally, this paper gives Matlab/Simulink simulation results to verify the practicality and effectiveness of the proposed adaptive sliding mode controller.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 전문대학교육위원
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• pp.110-113
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• 2004

PV model is presented based on the shockley diode equation. The simple model has a photo-current source, an single diode junction and a series resistance and includes temperature dependences. An accurate PV module electrical model is presented, matching with boost converter MPPT strategy and demosnstarted in Matlab for a typical general purpose solar cell. Given solar insolation and temperature, the model returns current vector and MPP.

• 제어로봇시스템학회논문지
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• 제21권1호
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• pp.28-33
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• 2015

In this paper, we propose a near optimal controller design method for permanent magnet synchronous generators (PMSGs) of MW-class direct-driven wind turbine systems based on SDRE (State Dependent Riccati Equation) approach. Using the solution matrix of an SDRE, we parameterize the optimal controller gain. We present a simple algorithm to compute the near optimal controller gain. The proposed optimal controller can enable PMSGs to precisely track the reference speed determined by the MPPT algorithm. Finally, numerical simulation results are given to verify the effectiveness of the proposed optimal controller.

• 전력전자학회논문지
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• 제19권6호
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• pp.549-556
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• 2014

This study proposes a parallel operation strategy for small wind turbine systems. A small wind turbine system consists of blade, permanent magnet synchronous generator, three-phase diode rectifier, DC/DC buck converter, and the battery load. This configuration has reliability, simple control algorithm, high efficiency, and low cost. In spite of these advantages, the system stops when unexpected failures occur. Possible failures can be divided into mechanical and electrical parts. The proposed strategy focuses on the failure of electrical parts, which is verified by numerical analysis through equivalent circuit and acquired general formula of small wind power generation systems. Simulation and experimental results prove its efficiency and usefulness.

• Journal of Power Electronics
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• 제18권3호
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• pp.826-840
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• 2018

This paper presents a distributed maximum power point tracking (DMPPT) algorithm based on the reference voltage perturbation (RVP) method for the PV modules of a series PV string. The proposed RVP-DMPPT algorithm is developed to accurately track the maximum power point (MPP) for each PV module operating under all atmospheric conditions with a reduced hardware overhead. To study the influence of parameters such as the controller reference voltage ($V_{ref}$) and PV current ($I_{pv}$) on the PV string voltage, a small signal model of a unidirectional differential power processing (DPP) based PV-Bus architecture is developed. The steady state and dynamic performances of the proposed RVP DMPPT algorithm and small signal model of the unidirectional DPP based PV-Bus architecture are demonstrated with simulations and experimental results. The accuracy of the RVP DMPPT algorithm is demonstrated by obtaining a tracking efficiency of 99.4% from the experiment.