Seddik Hadji

Long-term PV system performances evaluation by only the main weather parameters data uses. Case of study: Desert and arid climate

The Main objective of this work consist to evaluate the long-term performances of a photovoltaic systems according to the φ-f-chart concept in where only monthly mean values of the main weather parameters are used. Then, based on different equation representing the retained method and those leading reconstituting the monthly mean daily and hourly solar radiation data, a MATLAB program is developed and theoretical investigation of its accuracy was made by comparing the long-term performances of a proposed PV system evaluated by the developed MATLAB program to those presented in literature. Thus, from the obtained results it is observed that the developed program calculates the photovoltaic system performances with a good accuracy and can used as tool for such study of any climate. As application, the developed program was used to evaluate the long performances of a PV system used to cover an electrical load relative to 10 individual houses situated in remote site of Ghardaia region. Ghardaia is situated in the north of Algerians Sahara and characterized by a desert and arid climate. among the obtained results, the PV array and the storage size effect on the PV system performances has been lighted, a PV solar system dimensions for a total load covertures is proposed and that leading optimizing the PV array is presented for a partial electrical load covertures is presented also.

A simplified average model and analysis for an n-parallel connected inverters

The increase of power demand and the use of clean energy make the connection of power electronics building bloc in the heart of the current research. The parallel connection of inverters is then considered to be a solution for the high current required at the output which cannot be handled by a single inverter. In this context, average modeling allows the n-parallel connected inverters to be analyzed accurately and rapidly without requiring the complexity of the full switched inverter topology. The obtained equivalent circuit model makes easier the design of the control loop and decreases the simulation time. The analytical solution of the n-parallel connected inverters shows how the different zeros of the common characteristic equation of all the transfer functions can move in the s domain depending on the inverters parameters. An important trade-off between stability performances and efficiency is encountered. Finally, a simplified average equivalent circuit model is developed whatever the number n of inverters to be connected in parallel is, for the open loop case.

Technical and economic study of a stand-alone wind energy system for mountainous rural area electrification in Algeria

The present work is the investigation of a specific SWES. This system is designed to provide enough power for domestic use that satisfies a single households demand and allows a certain level of autonomy. The whole work is based on simulation. Models are elaborated to simulate the power source (wind turbine), a storage battery, the electrical load and the relevant meteorological conditions, in addition to other items that are needed to represent the SWES satisfactorily. MATLAB/SEVIULINK software is used for the whole system simulation. Focus is put onto the power source and battery. The load situated in Bouzareah in Algeria is represented as a power demand that needs be satisfied. Finally, the economic analysis has resulted in the calculation of the installed total cost, kWh cost, and the actualized total cost for the wind energy source. The simulation results indicate that the coverage provided by the wind/battery system depends on the wind turbine nominal power. It depends also on the local wind speed distribution as far as the economic results are concerned. It appears that the cost of the energy produced by the wind/battery system is very high (1.2-2.5S/kWh) compared to those corresponding to conventional installations (0.4S/kWh). This, however, is not to be considered as a negative determinant factor since the local authorities plan to manufacture renewable energy equipment locally and, by doing so, cancel the effects of subsidizing the local fossil fuels on the imported machines costs, which will in turn be favorably reflected on renewable energy costs.

Optimum SPWM parameters for unbalanced grid voltage of n parallel connected inverters

One of the major challenges of paralleling inverters are the circulating currents and the output current distribution along the units. This affects the overall efficiency of the circuit and furthermore, the ratings of a given inverter might be exceeded. Besides these difficulties comes the case where an unbalanced grid voltage or impedance influences the output current quality. Unbalanced and distorted output current is a serious power quality problem. This paper describes a possibility of reducing unbalance by changing the operating parameters. A proposed method based on the average phase-leg technique is developed to choose the appropriate sinusoidal pulse width modulation (SPWM) parameters. The analytical solution is obtained independently of the number of inverters to be connected in parallel. This will improve greatly the quality of the three-phase output current of the n parallel-connected inverters.

Study of Autonomous Wind Energy Systems with Battery Storage (AWESBS) for Mountainous Rural Area Electrification in Algeria

This paper presents a simulation investigation of a specific AWESBS basing on MATLAB/SIMULINK software. The considered household load is situated in BouzarA©ah in Algeria. An economic analysis has been also considered. As simulation results, it is observed that the coverage provided by the wind/battery system depends on the wind turbine nominal power. It is observed also that it depends on the local wind speed distribution as far as the economic results are concerned. It appears that the cost of the energy produced by the wind/battery system is very high (1.2 - 2.5

Vector optimised harmonic elimination in multilevel inverters/converters - A solution

/kWh) compared to those corresponding to conventional installations (0.4

Modeling and simulation of the fixed-speed WECS (wind energy conversion system): Application to the Algerian Sahara area

/kWh). This, however, is not to be considered as a negative determinant factor since the local authorities plan to manufacture renewable energy equipment locally and, by doing so, cancel the effects of subsidizing the local fossil fuels on the imported machines costs, which will in turn be favorably reflected on renewable energy costs.

Sun Tracking Mechanism Effects on Flat Plate Photovoltaic System Performances for Different Step Time and Main Parameters Affecting the Obtained Gains: Case of North Africa and Mediterranean Site

The main challenge in determining the optimized switching angles in PWM inverter/converter applications is finding solutions to sets of nonlinear equations. It is useful all existing solutions are detected so as only those yielding the best system performance can be selected. Several algorithms have recently been published which allow derivation of solutions, based on specific criteria and smooth DC link voltage. These no longer hold when link capacitor size is reduced. This situation is encountered in systems in which reduction of link capacitor size is a desirable feature, such as in traction and renewable energy systems. Vector optimized harmonic elimination PWM strategy (VOHEPWM) helps to restore the efficiency of optimized harmonic elimination PWM strategy (OHEPWM) but due to DC link voltage ripple more than one solution may exist. In this paper, solution determination is considered in the case of a single-phase multilevel cascaded VSI inverter. The derived results and simulation regarding the studied scheme are presented.