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In this paper, an experimental analysis and validation of a simple reconfigurable photovoltaic (PV) array is carried out. An assessment of a new reconfiguration method based on fuzzy logic (FL) under partial shading conditions is introduced. Furthermore, a recursive least squares based irradiance estimator is proposed aiming to reduce the investment cost of the dynamic PV array. An experimental comparison with other estimators showed the high precision of the proposed estimator. The estimation error has decreased by an average of 10% compared to the first estimator (based on the PV current and voltage measurement) and by 4.28%compared to the second estimator(based on the PV current measurement). On the other hand, the results validated the FL Controller ability to switch to the appropriate configuration under prevailing shading conditions. The method was tested for a simple configuration, however it could be generalized for small-scale configurations as residential house (average power output equal to 5 kWh). To evaluate the performance of the FL method an extended simulation of dynamic PV array of 16 PV modules is also realized. The mismatch loss is mitigated by nearly 50% compared to fixed Total-Cross-Tied and 8% compared to basic Irradiance Equalization techniques.

Photovoltaic (PV) modules suffer from a reduction of electric conversion due to the high operating temperatures of the PV cells. Hybrid photovoltaic/thermal (PV/T) technology represents an effective solution for cooling the PV cells. This paper discusses a theoretical study on a novel bi-fluid PV/T collector. One dimensional steady-state numerical model is developed, and computer simulations are performed using MATLAB. This numerical model is based on a pilot PV/T plant, installed in the Campus of the University of Catania, and was experimentally validated. The design of the proposed bi-fluid PV/T is based on a commercial WISC PV/T collector, to which are added an air channel, an aluminum absorber with fins, and a layer of thermal insulation. The analysis of the thermal behavior of the proposed collector is carried out as a function of the flow rate of the two heat transfer fluids (air and water). Finally, the comparative analysis between the conventional water-based PV/T collector, namely PV/T, and the bi-fluid (water/air-based) WISC PVT, namely PV/Tb, is presented for both winter and summer days. For the investigated winter day, the numerical results show an overall improvement of the performance of the bi-fluid PV/T module, with an increase of thermal energy transferred to the liquid side of 20%, and of 15.3% for the overall energy yield in comparison to the conventional PV/T collector. Instead, a loss of 0.2% of electricity is observed. No performance improvements were observed during the summer day.

Compared to other transportation technologies, fuel cell hybrid electric vehicles have been widely considered as one of the most promising alternatives for transport applications, due to their zero-emission, low noise, and high efficiency. This paper presents an energy management strategy for a hybrid electric vehicle powered by a fuel cell as the main source and Li-Ion battery as a secondary source. Our proposed approach is based on fuzzy logic and aims to decrease hydrogen consumption while increasing the durability of power sources by respecting their dynamic constraints as well as the battery’s state of charge. The fuzzy logic controller takes as inputs the load power and the battery state of charge and outputs the fuel cell power. The simulation model of the hybrid electric vehicle and its energy management strategy are established using MATLAB/Simulink. The simulation results show the correct functioning of our model and demonstrate that the proposed control strategy shows a good performance in improving fuel economy and the effective distribution of energy between sources.

Random network coding (RNC) for Error Correction have been the subject of intense research lately. However, in wireless sensor networks (WSNs) the correlation between the received symbols, from the same cluster head (CH), provoke the column correlation on the generator matrix of array Low-Density Parity-Check (LDPC) codes, whereby many columns of this matrix do not offer any additional information, thus the most important properties are lost despite the fact that the generator matrices are more easily dispersed. In this paper, the authors describe each step of the problem-solving algorithm employing efficient coding techniques focusing on improvement planning at Bit-error rsate (BER) vs signal-to-noise ratio (SNR) curves, in dense WSN, between CHs and the base station (BS) node. They use efficient coding techniques approach based on RNC and LDPC codes using the Time Division Multiple Access (TDMA) method. They generalize the notion of RNC-LDPC, study their properties and formulate the main steps of the proposed algorithm reconstruction method. The simulation results demonstrate that this approach is more effective in improving the BER using the proposed algorithm. Moreover, subsequently ameliorate the technical properties offered by this codification type.

In solar photovoltaic system, tracking the maximum power point (MPP) is challenging task due to varying climatic conditions. Moreover, the tracking algorithm becomes more complicated under the condition of partial shading due to the presence of multiple peaks in the power voltage characteristics. This paper introduces a novel method to track the global maximum power point under partially shaded conditions. The method combines an artificial neural network controller with a scanning algorithm. The PV system along with the proposed MPPT algorithm was simulated using Matlab/Simulink environment. The simulated system was evaluated under uniform and non-uniform irradiation conditions. For comparison, an improved variable step P&O with global scanning (PO&GS) and incremental conductance controller based on a fuzzy duty cycle change estimator (FLE) with direct control were used and the results show that the proposed approach is effective in tracking the MPP and presents fast response time.

In this paper, the authors demonstrate the existence of a new type of losses later called ’signal breathing losses’. They have adopted this name because when the optical signal propagates in the propagation channel it changes its size and its position each half period. These dimensions changes will force the signal to get out from the transmission channel with signal losses and part of its proper power making it less confined. They have been able, theoretically and experimentally, to measure small variations in the signal which propagates in the optical propagation channel to 3D or in the plans XY, XZ and YZ. Furthermore, the authors measured and quantified the signal breathing losses based on the depth of corrugation, the size and of the number of periods. Then they affirmed that this type of loss increases with a significant number of periods, with periods of large dimensions, or disturbances to index modulation characterized by important depths. These measures were performed on a set of Bragg filters done on an optical propagation channel of type broadcasted waveguide. The authors believe the ’signal breathing’ phenomenon is similar to that of 2G and 3G wireless systems including code-division multiple access (CDMA) which is the cell breathing phenomenon due to alteration of the data traffic.

International audience; This paper presents the modeling, control and optimization of a photovoltaic water pumping system. The DC-DC boost converter is used as a mediator between a Solar Photovoltaic (SPV) array and the Voltage Source Inverter (VSI) to feed the brushless DC (BLDC) motor.A centrifugal pump is connected to this motor in order to use the water pumped afterwards tomultiple applications. Maximum Power Point Tracking (MPPT) control techniques play a vital role in efficiency improvement of photovoltaic (PV) systems. It is mainly used to extract maximum possible power of the PV modules under any condition of solar irradiation. For this reason, P&O algorithm is used due to its high performance and its simplicity of implementation. The boost converter, over the various common DC-DC converters, offers many advantages in SPV based applications, such limiting the starting inrush current of the motors. Using a BLDC motor is found to be the best option because of its high efficiency, supreme reliability, better performance, and requires low maintenance, over a wide range of speeds. The considered model as well as the control strategy has been implemented in MATLAB/Simulink environment. The results show the effectiveness of the studied photovoltaic water pumping system.

Compared to conventional PV/T solar collector, the bi-fluid PV/ $T$ type enables to extract more heat producing hot air and hot water and thus increasing the total efficiency per unit of area. The use of both fluids leads to provide a variety of PV/ $T$ thermal applications. In this paper, a mathematical modeling of a bi-fluid photovoltaic/thermal PV/ $T$ solar collector type is developed and simulation was performed using MATLAB software. Furthermore, a performances comparison is carried out for four bi-fluid PV/ $T$ collectors using different cooling fluid (eg.air,water) in simultaneous operating mode. In this context, the temperature distribution in different collectors layers, electric power generation efficiency and thermal power efficiency are evaluated and analyzed. According to obtained results, water- water cooled PV/ $T$ collector proves a good effectiveness and reaches a higher electrical and thermal efficiency respectively of 11.16 % and 54.22%. This bi-fluid type is considered as the most provider of hot water in contrary to Air-air cooled PV/ $T$ witch providing more hot air.

When the panels in a photovoltaic generator (PVG) are subjected to Partial Shading (PS), some bypass diodes may turn on, and consequently multiple peaks in the Power -Voltage (P-V) characteristic are produced which reduces the output power. For an optimal GPV power extraction, one of emerging PS mitigation techniques is to reconfigure the PVG by altering the electrical connections between panels according to prevailing conditions. This paper presents a reconfigurable PV architecture based on irradiance equalization row approach for a PVG connected on Total cross tied (TCT) scheme. The proposed technique uses fuzzy logic as an optimization tool to obtain uniform shade dispersion throughout the PVG, either keeping the same number of panels in each row or forming rows with different number of PV panels. To evaluate the effectiveness of proposed fuzzy logic controller (FLC), extensive simulations with different shade patterns are carried out on Matlab/Simulink. Thorough analysis with the help of characteristics curves and the results obtained for the full PV chain conversion are performed. Results of simulation show that the proposed reconfiguration method exhibit superior results as compared to fixed TCT interconnection and enhanced irradiance equalization (IEq) method in terms of efficiency, power loss and response time.

The droop control scheme was generally employed in micro-grids (MG), however the main drawbacks of this scheme is its weak performances in reactive power sharing, mainly because of the unequal line impedances. To find a solution of the reactive power sharing inaccuracy, a control methodology based on an adaptive virtual impedance (AVI) is presented. The magnitude drop is adjusted to recompense the low voltage drop in the voltage caused by unequal feeder impedance of distributed generation (DG) units, without using communication links. The scheme of the controller is exposed, analyzed and simulated using MATLAB/SimPowerSystems. Results demonstrated that the adopted methodology can reduce the reactive power sharing error.

Dust deposition on the front of photovoltaic /thermal collectors presents greatest issues in some regions (desertic regions). It's considered as key parameter affecting much more collector's performances. In the present work, a particular attention has been paid to dust deposition effect on the electrical and thermal performances of photovoltaic /thermal collector PV/T.A model of sheet-and-tubes PV/ T collector is developed and validated with experimental data available in literature. The obtained results show that the dust significantly affects the electrical and thermal efficiencies. An increase of dust deposition of 8g/m2 causes an electrical and a thermal output reduction respectively of 28% and 21%. Better electrical and thermal performances have been noted for PV/ T without dust. Moreover, a good agreement has been observed between obtained results and the presented results available in literature.

The technology of photovoltaic-thermal solar collectors offers an attractive option for the simultaneous production of electrical and thermal energies. This technology finds interesting applications in the fields of desalination, sensitive heating/cooling and other related industrial processes. In this paper, we study the performance of a photovoltaic-thermal solar power plant operating in a Mediterranean city (Catania, Italy). A novel numerical model for a solar plant, constituted by uncovered photovoltaic-thermal solar collectors, the hydronic and electric circuits, and thermal solar tank, is presented and validated with experimental data. The developed model, based on energy balance equations for each Photovoltaic-Thermal Solar plant component, allows determining the state and dynamic behaviour of the system. The set of equations attained is resolved via the Runge-Kutta (RK4) numerical method in MATLAB software. Moreover, the built model allows considering the effects of solar radiation, outdoor temperature, wind velocity, the temperature in the thermal storage, flow rate and features of the photovoltaic-thermal solar panel, on the electrical and thermal energy production. The performances of the photovoltaic-thermal solar power plant have been evaluated and analysed. In particular, hourly temperatures achieved in the solar tank as well as the voltage in open circuit condition are calculated and compared with the observed experimental data. Furthermore, such analysis highlights a very good correlation between experimental and simulated results with a coefficient of determination higher than 0.96 and a root mean square error lower than 7%. During the period of survey, the investigated Photovoltaic-Thermal Solar plant provide an average daily energy production of 0.83 kWh/m2 of electrical energy and 0.53 kWh/m2 of thermal energy.

In the case of partial shadowing or photovoltaic (PV) module failure, the power provided by photovoltaic solar array significantly decreases. A promising technique to mitigate these power losses is based on the dynamic reconfiguration of the electrical connections between the PV modules. This article proposes a reconfigurable PV architecture based on Total-Cross-Tied (TCT) configuration and improved irradiance equalization (IrEq) algorithm. The PV architecture with the proposed optimization algorithm was simulated using Matlab/Simulink environment and compared to the basic equalization irradiance algorithm. The advantages of the proposed algorithm are simplicity and meaningful provision improvements in array power generation, along with the reduced processing time.

The efficiency of PV module is improved by combining a PV module and a thermal collector in one unit, resulting in a hybrid photovoltaic and thermal collector (PV/ T). The PV/ T system is a new solar and thermal technology which can provide simultanuously electrical and thermal energy. This kind of technologies can be used easily according to users demands. The aim of this paper is the design of an energy system based on PV/ T collector applied to a habitation. The proposed system in this study consists mainly of the PV/ T collector, thermal storage tank, battery and the electrical and thermal loads. Based on the developed model of PV / T system, both the thermal and electrical performances of the collector are investigated and the energy needs for the habitation are determined. The results show that the cogeneration system based on the hybrid collectors PV/ T is a complete energy system to supply electricity and heat at home.

This paper introduces a maximum power point method (MPPT) based on an artificial neural network (ANN) and a scanning algorithm. The proposed MPPT is applied to pumping system. The system is composed of solar generator, boost converter and centrifugal pump load driven by a DC motor. A complete simulation of the system is developed in MATLAB/SIMULINK under different weather conditions. The results obtained verify that the ANN controller shows a significant improvement in the power extraction performance especially in terms of tracking efficiency, when compared with modified Perturb and observe controller, and consequently the quantity of the pumped water gained by the ANN method is higher.