LINK:
http://www.mediafire.com/file/qq3yb0jl688j8ro/simulacion_de_circuitos_electronicos_de_potencia_con_pspice-amoros.pdf
"OBRIGADO DEUS PELA VIDA,PELA MINHA FAMILIA,PELO TRABALHO,PELO PÃO DE CADA DIA,PROTEGENOS DO MAL"
“SE SEUS PROJETOS FOREM PARA UM ANO,SEMEIE O GRÂO.SE FOREM PARA DEZ ANOS,PLANTE UMA ÁRVORE.SE FOREM PARA CEM ANOS,EDUQUE O POVO.”
“Sixty years ago I knew everything; now I know nothing; education is a progressive discovery of our own ignorance. Will Durant”
quarta-feira, 25 de outubro de 2017
segunda-feira, 23 de outubro de 2017
A New High Efficient Transformerless Inverter for Single Phase Grid-tied Photovoltaic System with Reactive Power Control -Monirul Islam Power Electronics and Renewable Energy Research Laboratory (PEARL) Department of Electrical Engineering University of Malaya
A New High Efficient Transformerless Inverter for Single Phase Grid-tied Photovoltaic System with Reactive Power Control
Monirul Islam Power Electronics and Renewable Energy Research Laboratory (PEARL)
Department of Electrical Engineering University of Malaya Kuala Lumpur, Malaysia
Abstract—There has been an increasing interest in transformerless inverter for grid-tied photovoltaic (PV) system due to low cost, high efficiency, less weight, etc. Therefore, many transformerless topologies have been proposed and verified with real power injection only. Recently, almost every international regulation has imposed that a definite amount of reactive power should be handled by the grid-tied PV inverter. According to the standard VDE-AR-N 4105, grid-tied PV inverter of power rating below 3.68kVA, should attain power factor (PF) from 0.95 leading to 0.95 lagging. In this paper, a new high efficient transformerless topology is proposed for grid-tied PV system. The new topology structure and detail operation principle with reactive power flow is described. The proposed circuit structure does not lead itself to the reverse recovery issues which allow utilizing MOSFET switches to increase the overall efficiency. Finally, to validate the proposed topology, a 1kW laboratory prototype is built and tested. The experimental results show that the proposed topology can inject reactive power into utility grid without any additional current distortion and leakage current. The maximum efficiency and European efficiency of the proposed topology is measured and found to be 98.54% and 98.27%, respectively.
Keywords—common mode, converter, high efficient, leakage current, reactive power, transformerless.
LINK ORIGINAL WEB
https://umexpert.um.edu.my/file/publication/00005361_125971.pdf
sábado, 21 de outubro de 2017
Analysis and Design of Single-Phase Photovoltaic Grid-Connected Inverter - Jaehwe Shim Department of Embedded SW Graduate School, Kwangwoon University Seoul, Korea
Analysis and Design of Single-Phase Photovoltaic Grid-Connected Inverter
Jaehwe Shim Department of Embedded SW
Graduate School, Kwangwoon University Seoul, Korea
Abstract
This paper proposed a new maximum power point tracking(MPPT) algorithm to find true maximum power point(MPP) for mismatched PV(Photovoltaic) modules. And also, various anti-islanding algorithms for grid-connected PV system were analyzed comparatively. At first, in order to have PV PCS maximum power generation efficiency, maximum power point trackers are used to operate a solar PV panel at its MPP. A number of MPPT algorithms has been used in the past such as P&O, IncCond, etc. But these algorithm cannot track true maximum power point under mismatched PV modules caused by clouds, shadow, and snow. The multiple local maxima can be existed on PV characteristic curve under mismatched PV modules. Therefore, the proposed MPPT algorithm, which is capable of tracking the true MPP under mismatched PV, is verified by simulation and experiment. In addition, this paper covered various anti-islanding methods for distributed grid-connected PV PCS. The islanding is that the phenomenon wherein the distributed PV PCS does not detect the interruption due to the power failures and faults, but dose continue operation. Islanding phenomenon can cause to have maintenance engineer in danger and to have application load damaged. Therefore grid-connected PV PCS must be disconnected while detecting the islanding phenomenon within the specified time, which secures safety and reliability. In this paper past various anti-islanding algorithms were explained and verified validity comparatively. For the validity of the proposed MPPT algorithm, 3kW PV system was designed with connected PV simulator.
LINK
http://www.mediafire.com/file/zxhzxcphv8p7la1/Analysis_and_Design_of_Single_Phase_Photovoltaic_Grid_Connected_Inverter.pdf
Power Conversion Technology for Grid-connected PV inverter-Woo-Jun Cha (차 우 준) Department of Electrical Engineering Pohang University of Science and Technology
Power Conversion Technology for Grid-connected PV inverter
Woo-Jun Cha (차 우 준)
Department of Electrical Engineering
Pohang University of Science and Technology 2015
ABSTRACT
This thesis proposes hardware circuits and control algorithm of grid-connected photovoltaic (PV) inverters having high efficiency. PV inverter can be classified into singlephase and three-phase inverter according to power capacity. A micro-inverter system is proposed for the single-phase inverter. This system is composed of step-up dc-dc converter that uses an active-clamp circuit with a series-resonant voltage doubler and a high efficiency inverter with single-switch-modulation. During the step-up dc-dc stage, the active-clamp circuit provides zero-voltage switching turn-on, recycles the energy stored in the leakage inductance of the transformer, and limits switch voltage stress. A series-resonant voltage doubler is used on the transformer secondary side to remove the reverse-recovery problem of the rectifier diodes. During the inverter stage, to improve efficiency and reliability in the proposed inverter, only single switch is modulated at switching frequency without shoot-through problem. This whole process minimizes power losses and eliminates a mismatch of a capacity between the PV panel and PV inverter, so the proposed micro-inverter is suitable for use in a single-phase grid connected PV inverter. A prototype design and experimental results are given to verify the proposed system. A novel space-vector modulation (SVM) for a three-phase PV inverter with simple software implementation is proposed. The conventional SVM algorithm for the three-phase PV inverter requires complex computations, such as square root and arctangent, and a sector selection algorithm. The proposed SVM algorithm can determine directly on-state times of switches without complex computations and complex sector selection algorithm. Experimental results show high performance of the proposed algorithm for the three-phase PV inverter.
LINK
http://www.mediafire.com/file/u6wnmz2xww2x80f/POWER_CONVERSION_TECHNOLOGY_FOR_CONNECTED_PV_INVERTER.pdf
Assinar:
Postagens (Atom)