• Title/Summary/Keyword: perturbation and observation

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A Study on the Two-Mode MPPT Control Algorithm and Efficiency Evaluation Method (Two-Mode MPPT 알고리즘 연구 및 효율평가법)

  • Yu, Gwon-Jong;Kim, Ki-Hyun;Jung, Young-Seok;Kim, Young-Seok
    • Journal of the Korean Solar Energy Society
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    • v.21 no.1
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    • pp.11-20
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    • 2001
  • In this paper described common MPPT(Maximum Power Point Tracking) control algorithm; Constant Voltage Control, P&O(Perturbation and Observation), IncCond(Incremental Conductance), and investigated it's efficiency. Through simulation and efficiency evaluation, analyze the steady/transient states characteristics and efficiency of control algorithms respectively. Also, To high-efficiency proposed Two-mode MPPT control for improve on the existing control algorithm. Moreover, this paper suggested a topology for MPPT measuring efficiency and a method of examination.

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The MPPT Control oh Photovoltaic System using FVSS-PO Method (FVSS-PO를 이용한 태양광 발전시스템의 MPPT 제어)

  • Ko, Jae-Sub;Chung, Dong-Hwa
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.27 no.11
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    • pp.20-26
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    • 2013
  • This paper proposes the maximum power point tracking(MPPT) control of photovoltaic system using fuzzy based variable step size perturbation & observation(FVSS-PO) method. Conventional PO and incremental conductance(IC)MPPT control algorithm generally uses fixed step size. A small fixed step size will cause the tracking speed to decrease and tracking accuracy of the MPP will decrease due to large fixed step size. Therefore, the fixed step size can't be satisfying both the tracking speed and the tracking accuracy. This paper proposes FVSS-PO MPPT algorithm that adjusts automatically step size of PO by fuzzy control according to operating conditions. The validity of MPPT algorithm proposed in this paper prove through compare with conventional PO MPPT algorithm.

A study of Improved P&O MPPT Algorithm go with a Dynamic characteristic of Photovoltaic System (태양광 시스템의 동작특성에 따른 개선된 P&O MPPT 알고리즘 연구)

  • Lee, Seung-Hee;Jang, Ki-Young;Kim, Sang-Mo;Kim, Ki-Hyun;Yu, Gwon-Jong
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.107-110
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    • 2009
  • The photovoltaic power system is effected by atmospheric condition. Therefore, The maximum power point tracking(MPPT) algorithm of the Photovoltaic (PV) power system is needed for high efficiency. Many MPPT techniques have been considered in past, but In this paper, the author analyzes widely known P&O MPPT algorithm and ImP&O algorithm, and presents new MPPT algorithm complementing weaknesses of other two algorithms.

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Modified-PO Method to Improve the MPPT Performance of PV System (태양광 발전의 MPPT 성능 개선을 위한 변형된 PO 방법)

  • Ko, Jae-Sub;Chung, Dong Hwa
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.29 no.12
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    • pp.40-46
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    • 2015
  • This paper proposes the method which is improved a performance of PO MPPT control in PV system. The PO method is continually changed voltage toward direction that increases power, and if output power is decreased by changing voltage, a power of the conventional PO method is changed to a power before one step. These operations causes reduce of MPPT performance. Therefore, this paper proposes the MPPT method that can be improved the performance of the conventional PO method. When voltage is changed to direction of reducing power, the method proposed in this paper is changed to the voltage the opposite direction of twice step size. The MPPT performance of proposed method in this paper is compared with conventional PO method and proved the validity of this paper using these results.

ANN-based Maximum Power Point Tracking of PV System using Fuzzy Controller (퍼지 제어기를 이용한 PV 시스템의 ANN 기반 최대전력점 추적)

  • Ko, Jae-Sub;Chung, Dong-Hwa
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.29 no.2
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    • pp.27-32
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    • 2015
  • A maximum power point tracking (MPPT) algorithm using fuzzy controller was considered. MPPT method was implemented based on the voltage and reference PV voltage value was obtained from Artificial Neural Network (ANN)-model of PV modules. Therefore, measuring only the PV module voltage is adequate for MPPT operation. Fuzzy controller is used to directly control dc-dc buck converter. The simulation results have been used to verify the effectiveness of the algorithm. The proposed method is compared with conventional PO(perturbation & observation), IC(Incremental Conductance) method. The nonlinearity and adaptiveness of fuzzy controller provided good performance under parameter variations such as solar irradiation.

Comparisons on Maximum Power Point Tracking Control of a Thermoelectric Generator on Vehicles (차량 적용을 위한 열전 소자 최대 전력 추종 제어 비교)

  • Jang, Yohan;Choung, Seunghoon;Bae, Sungwoo
    • The Transactions of the Korean Institute of Power Electronics
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    • v.26 no.3
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    • pp.159-166
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    • 2021
  • This study compares the maximum power point tracking (MPPT) control methods of a thermoelectric generator on vehicles. The researchers conduct comparisons on five different MPPT methods, including a fractional open circuit voltage method, a perturbation and observation (P&O) method, an incremental conductance method, a linear extrapolation-based MPPT (LEMPPT) method, and a LEMPPT/P&O hybrid method. These five MPPT methods are theoretically analyzed in detail, and the comparisons are conducted through MATLAB/Simulink simulation results. The comparison outcomes reveal that linear MPPT methods, including LEMPPT and LEMPPT/P&O hybrid methods, are more suitable for a thermoelectric generator on vehicles than the other MPPT methods examined in this work.

Maximum power point tracking method for building integrated PV system (건물용 태양광 컨버터의 최대전력 추종 기법 개발)

  • Yu, Byung-Gyu;Yu, Gwon-Jong
    • 한국태양에너지학회:학술대회논문집
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    • 2011.04a
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    • pp.299-303
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    • 2011
  • This paper proposes a novel sensorless maximum power point tracking (11PPT) algorithm for PV systems. The method is based on dividing the operating time into several intervals in which the PV terminals are short circuited in one interval and the calculated short-current of the PV is obtained and used to determine the optimum operating point where the maximum output power can be obtained. The proposed MPPT algorithm has been introduced into a current-controlled boost converter whose duty ratio is controlled to the maintain MPP condition. The same sequence is then repeated regularly capturing the PV maximum power. The main advantage of this method is eliminating the current sensor. Meanwhile, this MPPT algorithm reduces the power oscillations around the peak power point which occurs with perturbation and observation algorithms. In addition, the total cost will decrease by removing the current sensor from the PV side. Finally, simulation results confirm the accuracy of the proposed method.

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Study on the Grid-connected Photovoltaic Power System for Reducing Ripples of the PV Array Output (PV Array 출력리플 저감을 위한 계통연계형 태양광 인버터에 관한 연구)

  • Kim, H.J.;Chung, Y.H.;Lee, K.S.;Jon, Y.S.
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.1211-1212
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    • 2007
  • In the PV power system, output of the PV array must contain inherent ripples due to the single-phase inverter. So, the function of maximum power point tracking to increase the output efficiency of PV system is degraded. Therefore, to overcome this problem, this paper presents a control strategy for the reducing ripples of the PV array output in grid-connected photovoltaic power system. The proposed control system consists of two loops; the maximum power point tracking loop using the perturbation and observation method is used to calculate the reference solar array terminal voltage(Vref) for reducing ripples of the PV array output and the PI control loop is used to regulate the solar array output voltage according to the Vref. The performance of proposing control strategy is analyzed by means of the PSCAD/EMTDC simulation and experiment. As a result, we may obtain the high performance of the proposed control strategy.

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Comparison Study of Maximum Power Point Tracking Control with Changing of Radiation (일사량 변화에 대한 최대전력점 추종 제어의 비교 연구)

  • Choi, Jung-Sik;Ko, Jae-Sub;Chung, Dong-Hwa
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.6
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    • pp.1075-1082
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    • 2010
  • This paper analyzes a operating characteristic for maximum power point tracking (MPPT) of photovoltaic generation system. MPPT methods are used to maximize PV array output power by tracking maximum power point(MPP) continuously. To increase the output efficiency of PV system, it is important to have more efficient MPPT. MPPT algorithm is widely used the control method such as the perturbation and observation(PO) method, incremental conductance(IC) method and constant voltage(CV) method. In case of the radiation is changed, this paper proposes a response characteristic with MPPT control algorithms. Also, it proposes the direct for a novel MPPT control algorithm development through the analyzed data, hereby proves the effectiveness of this paper.

OBSERVATIONAL STATUS OF THE TEXTURE LARGE-SCALE STRUCTURE FORMATION MODEL

  • UMEDA HIDEYUKI;FREESE KATHERINE
    • Journal of The Korean Astronomical Society
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    • v.29 no.spc1
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    • pp.23-24
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    • 1996
  • We reexamined CDM texture large-scale structure (LSS) formation model. We confirmed that texture model is consistent with 4-year COBE data both in an open and a critical matter density (${\Omega}_0$ = 1) universes, and then obtained normalization for density perturbation power spectrum. We next compare the power spectrum with LSS observation data. Contrary to the previous literature, we found that texture model matches with these data in an open universe no better than in an ${\Omega}_0$ = 1 universe. We also found that the model is more likely to fit these data in a cosmological constant dominated ($\Lambda-$) universe.

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