Mounir Bouzguenda

Evaluating solar photovoltaic system performance using MATLAB

This paper focuses on the modeling of solar photovoltaic (PV) cell and the performance of typical solar PV panels in selected areas in the Sultanate of Oman. An accurate solar PV cell electrical model is based on the junction diode equations. The model consists of a photo-current current source, a single diode junction and a series resistance, and takes into account temperature and solar irradiation dependence. The model is developed using MATLAB/Simulink and is used to investigate the variation of the maximum power point for different temperatures and solar irradiation levels. Finally, the model is experimentally validated for a typical 30 Watt solar module connected to a variable load.

Design of an off-grid 2 kW solar PV system

Saudi Arabia is in need for clean and renewable sources of energy such as solar for electricity and water heating, wind, geothermal, tidal and biomass. This paper involves the design of a 2-kW standalone solar Photovoltaic system at King Faisal University and presents a methodology for technical and economic analysis of the proposed system with energy storage facility. The PV system will be built on top of the College of Engineering and will be used for research and academic purposes. The design, simulation and analysis were carried out using PVsyst V6.12 software package that takes into account the geography of the site, surrounding trees, buildings as well as the solar energy resources and available solar technologies. It was found that shading due to nearby buildings and trees had limited effects on the system performance. However, the study revealed that even though solar energy resources were abundant in the summer, high ambient temperatures drastically hindered the overall system performance for the given system components and reduced the solar cell efficiency by up to 16%. Losses due to shading varied between 0.70% and 4.2% depending on the panel spacing and field location.

Power losses reduction using solar photovoltaic generation in the rural grid of Hij-Oman

Distributed power generation using renewable energy offers a great flexibility in terms of generation, distribution and dispatching. This becomes more strategic when rural area grids are struggling to cope with high diesel fuel costs, dispersed loads and low load factors. This is why the main focus of recent research activities is on minimizing or totally displacing diesel based generation by using hybrid power systems combining wind turbines, solar photovoltaic systems, storage devices and fuel cells. For large rural grids, finding the right place to connect the solar photovoltaic systems must be strategic and optimized. Accordingly, this paper focuses on optimizing the point of connection of solar photovoltaic (PV) facilities in the rural area grid of Hij in the Sultanate of Oman.

Assessment of topologies to minimize leakage currents in transformerless PV inverters

Nowadays, the world is facing two challenges: the need for cleaner environment and the incessant increase in power demands. A situation that makes renewable energy sources, and particularly solar photovoltaics, more and more viable. Solar photovoltaic systems can be connected to the grid either with transformers or without transformers. In fact, the transformerless systems have been investigated and found to offer higher efficiency, smaller size and weight as well as more reduced cost. However, when no transformer is used, a common-mode voltage would appear and lead to leakage currents between the PV-array and the ground. This is why the main focus of recent researches is on minimizing or totally avoiding these leakage currents without causing any impact on the whole system efficiency. Accordingly, this paper deals with a comparison of promising solutions to achieve such a crucial goal.

Review of Common-Mode Voltage in Transformerless Inverter Topologies for PV Systems

When a galvanic connection between the grid and the PV array is made, a common-mode voltage exists which generates common-mode currents. These common-mode currents may produce electromagnetic interferences, grid current distortion and additional losses in the system. Therefore, to avoid the leakage currents that would penalize the transformerless power chains, it is worth focusing on topologies which do not generate common-mode currents. Some topologies available in the market touch more or less such a crucial requirement. However, some drawbacks generated by the non-utilization of the line transformer still exist.This is said, a small room for improvement still exists. The first goalof this reviewis to focus on recently developed topologies which do not generate common-mode voltage. Analysis and simulation results show that the HERIC topology has higher efficiency and does not generate a common-mode voltage. The second goal is to present the different ways to reduce harmonics in the inverter output and to maximize the PV cells output power.

Microcontroller-based inverter topology integrated in PV systems

Purpose – The purpose of this paper is to study the problem of the leakage currents in transformerless inverter topologies. It proposes a novel topology and how important the adopted control strategy on the power quality produced by the inverter. Design/methodology/approach – The paper presents an investigation of a novel transformerless inverter topology. It adopted a control strategy in which the DC source is disconnected from the inverter when the zero vectors of the control are applied. By using such control strategy, the electrical efficiency of the whole system was improved and the leakage current was significantly reduced. Findings – The paper provides a solution to minimize the leakage current in transformerless inverter topologies. Besides, the problem of zero-crossing distortions was totally eliminated. Research limitations/implications – Because of the high conversion ratio of the boost converter, the efficiency of the whole system needs to be enhanced. Practical implications – The paper includes the experimental results of the proposed topology which are in good match with the simulation results. Originality/value – This paper identifies a need to study the leakage current phenomena in transformerless inverter topologies.

Low cost microcontroller-based inverter integrated in PV systems

This paper deals with a novel transformerless inverter topology having high efficiency, low leakage current and no zero crossing distortions are encountered. In fact, the proposed topology is based on the conventional full bridge topology with an extra AC bypass branch to short circuit the load when the zero voltage of the control is applied. In this way, the current returning from the filtering circuit finds its path through the extra branch during the freewheeling period and remains at the AC side. This would increase the efficiency and decrease the leakage current. The control strategy of the proposed topology is based on a low cost microcontroller interfaced to two drivers to step up the MOSFETs gate voltages. The proposed inverter and its control strategy were implemented and promising results were obtained.