Applied Mechanics and Materials Vol. 905

Abstract: The amount of energy generated by an Organic Photovoltaic (OPV) system depends mainly on the following.Such as solar temperatures and irradiations. Depending on the high cost and low efficiency of an organic photovoltaic system, it can be operated at the maximum power point (MPPT) that changes with solar radiation, temperature or load variations. This work presents an improved algorithm for tracking the maximum power point (MPPT) of a OPV system under real climatic conditions. The proposed MPPT is based on the perturbation and observation (P&O) strategy and the variable pitch method which controls the load voltage to ensure optimum operating points of a OPV system.

Abstract: To our knowledge, very few models have described the thermal behavior of granular media or powders as a function of the mechanical stresses to which they are subjected. In recent years, many researchers have expressed great interest in establishing laws that can show the relationship between the apparent thermal conductivity and the mechanical behavior of granular media. This paper presents an experimental study of heat transfer enhancement using granular blocks. A number of experiments were carried out in the test section of a wind tunnel where velocity and temperature measurements were performed. The velocity profiles permitted us to have an idea on the flow structure in the presence of granular blocks. The temperature measurements under various operating conditions (various Reynolds numbers and granular blocks structures) led us to the conclusion that using granular blocks can improve the thermal transfer in comparison with the case of a smooth channel and this enhancement is strongly dependent on the geometrical and thermo-physical properties of these blocks.

Abstract: The degradation of the electrical performance of photovoltaic modules UDTS-50W exposed to the sun for a long period of about 10 years in a Saharan environment of Adrar was presented. In this article, the experimental results obtained during the analysis of the I-V characteristics of some UDTS-50W photovoltaic modules tested in the real conditions of the Saharan environment (Adrar region). The electrical performance degradation of the UDTS-50 W PV modules was identified by empirically analyzing the I-V and P-V characteristics and by visual field inspection of these modules, which were installed in a renewable research unit in a desert environment (URERMS). The comparison between the experimental characteristic curves IV and PV of the PV modules UDTS-50W and the reference in the standard test conditions (STC) shows that the degradation of the electrical performances is due globally by the delamination and the discoloration of the Ethylene-vinyl acetate (EVA) encapsulate after the long term exposure in a desert environment.

Abstract: This paper provides the modeling and control of stator active and reactive power for doubly fed induction generator (DFIG) under wind turbine systems using a direct power control (DPC) is applied to the grid side converter (GSC), also the rotor side converter (RSC) of the DFIG is controlling with the field control (FOC) to realize the decoupling control of the active and reactive power. For tuning the PI controllers is a tedious work and it is difficult to tune the PI gains optimally due to the nonlinearity and the high complexity of the system. This paper presents an approach to use the particle swarm optimization algorithm to design the optimal PI controllers for the rotor side converter (RSC) of the DFIG. Based on the simulation results, the PSO-PI provides lower value for the criteria and better response compared with the PI conventional.

Abstract: Various researchers have developed a model of conventional H₂O -LiBr absorption machines, with the aim of predicting their performance. In this paper, the methodology of the adaptation of the characteristic equations is applied; this model is able to represent the cooling capacity of the double effect absorption chiller by means of simple algebraic linear equation. As a result, it is concluded that a good agreement between the theoretical simulation using the thermodynamic model and the results obtained on the literature. The results achieved through the adapted characteristic equations model have a deviation less than 10% for the cooling capacity and the coefficient of performance COP, and less than 15% for the heat capacity comparing to the thermodynamic model results. The developed characteristic equations and their assessment are useful for the simulation and the control purpose.

Abstract: In this paper, we present a modeling of the photovoltaic array in order to tracking the maximum power point (MPPT) using a soft computing approach based on artificial neural network, The maximum power point tracking MPPT play a crucial role in photovoltaic systems for their ability to maximize the power output under varying conditions; The photovoltaic array modeled and implemented in matlab simulink environnement using the conventional perturb and observe algorithm for multiple ranges under varying temperatures and irradiances levels, a feed forward neural network collect the training data from the photovoltaic array simulink model, after the training process check, the neural network model tested with new temperatures and irradiance data to predict the maximum power point of the photovoltaic array, The developed neural network model shown an interesting results compared to simulink model based on classic perturb and observe algorithm.

Abstract: Because of The low complexity of passive filters (PF) compared to the active filter, their high efficiency, their ease of installation and their different topologies,theyremained the devices required in the power system. In order to minimize the harmonic distortion produced by the large industrial loads, harmonic filters should, therefore, be designed with the utmost rigor, because a poorly designed filter may amplify the undesired harmonics. The determination of the PFcomponents requires both adetailed study ofthe power system parameters, which influence the efficiency and economic viability of the harmonic compensation and the reactive power required by the load.This article studies the use of the Cuckoo optimization algorithm (COA), in order to designpassive filters with an improved power quality and reduced cost. The optimal filters are connected concurrently to the power system so that each individual Harmonic distortion respects the recommended limits. The results show that the optimized (PF) is effective, and has a lower cost.

Abstract: The increasing penetration of RES and the intermittent nature of various distributed power generation (DG) resources have created uncertainty in variable power production and power systems. The overall energy output of a wind farm may be optimized by strategically positioning wind turbines. This paper proposes a three-step strategy to dealing with the difficult-to-control problem of wind farm layout optimization. To construct the non-wake and wake impacts at various levels, three case scenarios are studied. The proposed strategy is used to a particular Ant-Lion Optimization Algorithm (ALOA) as a novel approach to producing highly efficient optimal output power, as well as case studies using actual wind data assessing potential turbine site. Finally, the simulation results demonstrate that the suggested approach is robust in ALOA design because it further reduces the objective function on the best new outcomes to implement all network restrictions acquired via the analysis.