Mohamed Louzazni

Control and stabilization of three-phase grid connected photovoltaics using PID-Fuzzy logic

The aims of this paper are to propose an intelligent hybrid control based in two methods of maximum power point tracking (MPPT) using fuzzy logic and classical PID controllers of a photovoltaic system under variable temperature and irradiance conditions, to improve the dynamic response, the efficiency and the stability of single stage three-phase photovoltaic grid-connected inverter. The combination of the intelligent fuzzy logic with the classical PID controller makes the control of nonlinear characteristic of photovoltaic array more feasible. The proposed intelligent hybrid PID-Fuzzy logic controller automatically varies the coefficients Kp, Ki and Kd under variable temperature and irradiation, load change and uses directly the DC-DC converter duty cycle as a control parameter. Finally, the new method gives a good MPPT operation ot any photovoltaic array under different conditions such as changing solar radiation and PV cell temperature. The simulation results and the comparison of results obtained separately from PID controller and hybrid proposed intelligent controller of PID-Fuzzy logic show the advantages of the proposed intelligent algorithm in terms of correctness and the feasibility, overshooting and stability and maintains its response better than the PID controller in many aspects.

Intelligent PID-Fuzzy logic control for three-phase grid-connected photovoltaic inverter

The aims of this works are to present an intelligent control based in fuzzy logic and PID controller for the maximum power point tracking (MPPT) of a photovoltaic system under variable temperature and irradiance conditions, to improve the dynamic response, the efficiency and the stability of single stage three-phase photovoltaic grid-connected inverter. The combination of the flexible and intelligent fuzzy logic with the classical PID controller makes the control of nonlinear characteristic of photovoltaic array more feasible. The proposed intelligent PID-Fuzzy logic controller automatically varies the coefficients Kp, Ki and Kd under variable temperature and irradiation. Finally the comparison of results, obtained separately from PID controller and proposed intelligent controller of PID-Fuzzy logic show the advantages of the proposed intelligent algorithm in terms of correctness and the feasibility, overshooting and stability and maintains its response better than the PID controller in many aspects.

Identification of Solar Cell Parameters with Firefly Algorithm

Due to the non-linearity, multivariable and multimodal features of current-voltage of solar cell models, the conventional methods are incapable to estimating the parameters of solar cell with high accuracy. Recently, the bio-inspired algorithms have attracted the attention. The firefly algorithm is nature-inspired stochastic optimization algorithm is among the most powerful algorithms in solving modern global optimization for nonlinear and complex system, based on the flashing patterns and behavior of fireflies swarm. In this paper, a firefly algorithm is proposed to extract the parameters of single diode model solar cell from experimental I-V characteristics. The results obtained by firefly algorithm are quite promising and outperform those found by the other methods.

An analytical mathematical modeling to extract the parameters of solar cell from implicit equation to explicit form

It was developed a new mathematical model to simplify the nonlinearity and complexity of mathematical equation of solar cell. Due of the complex characteristics the researcher used the iterative calculations to determine the maximum power point, fill factor, ideality factor, and parasitic series and shunt resistances of solar cell. We proposed a mathematical study based on derivation of basically nonlinear model of solar cell and normalized the current density and voltage to simplify the equation model. The new proposed model is applicable to a large variety of solar cells. Due to its mathematical simplicity the model will be suitable and easy for analytical modeling of complex current–voltage equation of solar cell on two and three dimensionals. The new analytical model equation have been tested and compared with the experimental results to add validity to the model.

Linearizing and Control of a Three-phase Photovoltaic System with Feedback Method and Intelligent Control in State-Space

Copyright ©2014 KIEEME. All rights reserved. This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited. pISSN: 1229-7607 eISSN: 2092-7592 DOI: http://dx.doi.org/10.4313/TEEM.2014.15.6.297 OAK Central: http://central.oak.go.kr TRANSACTIONS ON ELECTRICAL AND ELECTRONIC MATERIALS Vol. 15, No. 6, pp. 297-304, December 25, 2014

Comparison and evaluation of statistical criteria in the solar cell and photovoltaic module parameters’ extraction

ABSTRACT Recently, the extraction of photovoltaic parameters was the subject of intensive debate in the scientific literature. This paper presents an analysis and comparison of the use of the statistical errors in extraction of single and double diodes of the solar cell and photovoltaic module parameters. The compared errors are based on the utilisation of the firefly algorithm. The objective function used is adapted to minimise the absolute errors between the experimental and predicted current values. Two technologies of the solar cell are used to compare; a mono-crystalline silicon solar cell and the polycrystalline silicon photovoltaic module with 36 cells connected in series. The performance of the extracted parameters and current is compared with recent algorithms and techniques. The analysis and comparison of commonly used error measure help in evaluating the predictive ability of parameters extraction. The comparisons demonstrate that the firefly algorithm in statistical errors measure provides high performance and accuracy of the extracted parameters.

Comparative prediction of single and double diode parameters for solar cell models with firefly algorithm

Due to the non-linearity of current-voltage of solar cell model, the conventional methods are incapable to extract the parameters of solar cell with high accuracy. The implicit nonlinear equation describing the single and double diodes solar cell in five and seven parameters is rewritten as optimization problems with constraint functions and it is solved by using a firefly algorithm optimization. The firefly algorithm is a nature-inspired stochastic optimization algorithm, and able to solve modern global optimization for nonlinear and complex system, based on the flashing patterns and behavior of fireflys swarm. Moreover, this paper develops a unique solar cell modelling approach that incorporates search and optimization techniques for the determination of equivalent circuit parameters of RTC France Company mono-crystalline silicon solar cell single and double diodes at 33°C and 1000W/m2 from experimental current-voltage. The statistical errors are used to verify the accuracy of the results. Finally, accuracy of the extracted parameters is verified by comparing the current-voltage curve generated from simulation with those provided by determined experimentally and with different recent algorithms.

Full bridge three port converter power flow control using fuzzy logic controller

The concept of using renewable energy sources usage is increasing day by day but there is a limitation of it as we cannot use standalone renewable system. With standalone systems, the storage devices are used for backup power. The load and sources are interfaced by the power converters. In this paper, a new three port converter is analyzed. The analyzed converter is derived from full bridge converter which was split into two different cells; each cell is interfacing the input source. A cell is composed of two switches. The input to each switch in cell is inverted of other switch in a cell. A transformer is used between input and output port to provide isolation. The Fuzzy logic controller is used to control the power flow in three-port converter which interfaces a PV panel, a battery and an output port to the load. The difference between two powers, PV panel power and demanded power, is used as input for fuzzy logic controller and the output of fuzzy logic controller offers two signals: the first signal is for the first cell while the second signal is for the second cell; Simulation results, concerning the fuzzy control of power flow in various circumstances where obtained in MATLAB/Simulink.

Parameter estimation of photovoltaic module using bio-inspired firefly algorithm

The current-voltage characteristics of photovoltaic module are non-linear, multivariable and multi-modal and difficult to optimize the electrical intrinsic parameters. The conventional methods are incapable to optimize the parameters of photovoltaic module with high accuracy. Recently, the bio-inspired algorithm such as firefly algorithm has attracted the intention to optimize the non-linear and complex systems, based on the flashing patterns and behavior of fireflys swarm. Further, the firefly algorithm is nature-inspired stochastic optimization algorithm is among the most powerful algorithms. Moreover, the firefly algorithm is proposed in this paper to extract the electrical intrinsic parameters of photovoltaic module (Photowatt-PWP 201) in which 36 polycrystalline silicon cells are connected in series, at 45°C and 1000W/m2 from experimental current-voltage. The current predicted values with the photovoltaic module obtained analytical model are in good agreement with the experimental values used for the photovoltaic module parameters estimation.