Mohammadi Benhmida

Design and sliding mode control for PMSG based wind power system connected to a non-ideal grid voltages

This study presents a control scheme of the electronic interface of a grid connected Variable Speed Wind Energy Generation System (VS-WEGS) based on a Permanent Magnet Synchronous Generator (PMSG). The proposed system consists of wind turbines (WT) and 2 PMSGs connected to the electric network by back-to-back Voltage Source Converter (VSC) with a common dc-link. The generator-side converters are employed to attain Maximum Power Point Tracking (MPPT). The grid-side regulator controls the reactive power flow, the voltage at the dc link between both sides and the power factor during wind variations. The reliability and effectiveness of wind energy is shown to be depending on the applied control strategy. So, the control schemes are based on Sliding Mode Control (SMC) for control of both generators and grid-side converters of a VS-WEGS. The performance of the system has been demonstrated under varying wind conditions and under a grid voltage dip. The proposed SMC strategy is compared with the conventional Vector Control (VC) method. The simulation results show a good performance of the proposed sliding mode control.

Photovoltaic (PV) parameter estimation of a multicrystalline panel using developed iterative and non-iterative methods

Mathematical modeling of photovoltaic (PV) modules is essential for any performance optimization operation or diagnostic of the photovoltaic generator under changing environmental conditions. The limited data available are provided by commercial manufacturing datasheets. The accurately estimating of these parameters remains a challenge for researchers. There is great diversity in the models and the estimation methods i.e., iterative and non-iterative methods. In this paper we are interested in estimating the parameters of both complete (5-parameter) and simplified (4-parameter) single-diode PV models by non-iterative and iterative methods i.e., the Newton-Raphson and Halleys method. The aim is to predict the behavior of a multicrystalline Kyocera KC200GT module under real environmental conditions. A new parameter Series/Parallel Ratio (SPR) ranking photovoltaic modules is defined. Depending on the value SPR, we can neglect the series or shunt resistance of single-diode model without compromising accuracy. The proposed approach is a quick and non-iterative method that allows the estimation of PV parameters. It can be used in tracking applications of Maximum Power Point Tracking (MPPT) for on-line. The results obtained with non-iterative and iterative methods are compared with experimental data. The results are discussed in terms of precision and order statistical errors. They show the limits of the use of these approaches and their relevance. The method is verified by the simulation using MATLAB/Simulink environment.

Notice of Violation of IEEE Publication Principles Parameters identification of a Thin-Film photovoltaic panels

In this paper, our work consist to identify the parameters of both complete (5-parameter) and simplified (4-parameter) single-diode PV models by non-iterative and iterative methods. The objective is to predict the behavior of a Thin-Film module under real environmental conditions. A new parameter Series/Parallel Ratio (SPR) ranking photovoltaic modules is defined. According to the value SPR, we can neglect the series or shunt resistance of single-diode model without affect the accuracy. The results obtained with non-iterative and iterative methods are compared with experimental data. Simulations are performed in the MATLAB/Simulink environment.

Evaluation of Different PV Prediction Models. Comparison and Experimental Validation with One-Year Measurements at Ground Level

At the early stage of photovoltaic plants feasibility study, the assessment of the power production and the technology performances is a necessity. To do so, engineers usually use software’s and prediction models. Plenty of models are available in the literature, nevertheless, the selection of the most suitable one to be use in a specific climate is a hard task since no study deals with the inter-comparison of the existing PV production models. In this paper, the output of 12 from the most used PV production models were evaluated and their accuracy has been assessed versus one-year real measurement data from a PV module in different time resolutions. Results show that four models (M1, M2, M3 and M4) are the most adequate models to simulate the PV performances under harsh climatic conditions (case study of Benguerir city, Morocco) with a minimum hourly RMSE of 7.07% during spring, 4.23% during summer, 7.56% in autumn and 10.11% in winter.

Temperature influence on performance of a solar cell receiving direct sunlight and a halogen lamp irradiation

Physical parameters of a photovoltaic cell can be determined from its experimental current-voltage characteristic. The accurate determination of these parameters is particularly dependent on experimental measurements conditions. The reliability of measurements of temperature variations and intensity of solar radiation are dependent on the sampling time of the measurements. Controlling the radiation intensity and the temperature can be better achieved by using an artificial light source. However, the spectral characteristics of some artificial sources of radiation can cause a substantial increase in the temperature of solar cells. The characterization of a solar cell by using the sun as a source of radiation and considering its temperature and received radiation intensity as constants requires automation of the experimental setup. And this in order to acquire all of the characteristic current-voltage (I–V) in a sufficiently short time range. To this end, a programmable electronic control device was carried out in our laboratory. In this paper, we compare the obtained current-voltage characteristics of a photovoltaic solar cell under direct sunlight and with a halogen lamp, for different temperatures measured using an infrared camera.

Design of a new photovoltaic panel cooling system to optimize its electrical efficiency

In this paper we present the study of a hybrid photovoltaic/thermal panel (PV/T). It consists of a sheet form with several inputs-outputs opening (I/O) of coolant fluid, confined between the rear face of the panel and a Plexiglas support plate. The system is designed to maintain the temperature of the PV panel near ambient temperature. Heat transfer through the components of PV/T collector, taking into account energy losses by conduction, convection and radiation, are implemented by numerical simulation. The knowledge and control of the temperature in each point of the PV panel are important and permit to limit at best the temperature gradients across its surface. We present the thermal balance depending on the number of opening inputs/outputs of the coolant plate, the geometry of the collector and the cooling fluid flow rate. For specific configuration and operational conditions, we propose a law giving optimal cooling conditions of the PV module.

Analysis of technological factors's influence on solar cell's performance by PC1D simulation

In this work, we study the influence of various technological factors on silicon solar cells efficiency. We use simulation by personal computer one dimension software package (PC1D) solving equations describing the transport of electrons and holes in devices based on semiconductor materials. We highlight the most critical steps and the technological factors to be improved to increase solar cells efficiency. We also discuss the influence of cell front face reflection, impurity concentration of the emitter and the base as well as the introduction of a p+ layer known as BSF, to reduce recombination losses in the cell rear face.