Lana El Chaar

An Adaptive Photovoltaic Topology to Overcome Shading Effect in PV Systems

Shading in photovoltaic systems can cause many undesired effects. When shading occurs, the power generated from the PV system is much less than nominal power, increasing the electrical mismatching losses between PV system components. Active research to address this power loss focuses on static and adaptive systems. This paper addresses an adaptive system solution and proposes a new method to adaptively overcome losses due to shading during low radiation conditions. In addition, a statistical analysis for choosing the most feasible and efficient configuration for the system size is presented. The proposed system has been validated under shade conditions in a simulation and prototype experiment. The experiments are conducted using a PV system consisting of 10 PV modules located at the Petroleum Institute in the United Arab Emirates. The proposed system is shown to minimize the shading losses of the PV array in real time by an average of 100% under simulated conditions and 84% in practical experiments.

The GCC: Wind technology deployment potential

The Gulf Cooperation Council (GCC) countries, known fossil fuel producers, are well aware of this energy sources problems such as depletability and pollution. To address these issues, this region has shown willingness and determination in its mission of deploying renewable energy sources particularly wind energy to support and enhance their growth. The following is accomplished by investigating the suitability of these sources. This paper presents the wind potential and characteristics of this region by discussing the annual and monthly average wind speed. Based on the data obtained the locations were classified according to wind speed highlighting the applicability of wind energy in the GCC countries.

A novel Photovoltaic/Battery Structure for Solar Electrical Vehicles [PVBS for SEV]

In this paper, we propose a new flexible Photovoltaic/Battery charging Structure for Solar Electrical Vehicles (PVBS), where the interconnection of the system is dynamically changing based on current shading conditions across PV modules to provide intelligent system, as well as to provide flexibility, performance, and efficiency enhancement for the SEV. PVBS is expected to 1) provide a battery charging efficiency improvement over existing employed topologies; 2) provide new means to match the computing load with the PV system performance metrics shading and mismatches; 3) and provide elastic reconfigurable system expected to spur research advancements and innovations to make future SEV design smarter. A MATLAB simulation model and an actual test were conducted to verify the proposed configuration. These results show that the proposed system increases the efficiency of the traditional PV/Battery charging strategies and smoothes the shape of P-V curve to a single peak in the curve.

Interconnection between two variant frequency systems using HVDC links

Energy is the basic necessity of the modern world and the consumption is increasing everywhere. Efficient energy supply system is the backbone for smooth development of a country which requires interconnection between different areas and countries and transmission of power over long distances. HVDC is one of the systems which can provide power efficiently and have many advantages technically, economically and environmentally over the HVAC. This is why when it comes to interconnection and transmission over long distances, HVDC would be the first to discuss and study. Although interconnecting different frequency AC networks is one of HVDC applications, nobody has studied because simply nobody faced it practically. Ongoing projects are coming soon to connect a 60Hz network to different 50Hz networks. In this paper, an interconnection between two variant frequency systems (50 Hz and 60 Hz) using HVDC links was simulated and studied using PSCAD Software.

Photovoltaic System Conversion

Publisher Summary This chapter discusses the conversion of solar energy into electricity using photovoltaic system. There are two types of PV systems: the grid-connected PV system and the stand-alone PV system. Solar cells are composed of various semiconductor materials that become electrically conductive when supplied with heat or light. The voltage generated by the array depends primarily on the design and materials of the cell, whereas the electric current depends primarily on the incident solar irradiance and the cell area. Photovoltaic technology is used to produce electricity in areas where power lines do not reach. In developing countries, it helps improving living conditions in rural areas, especially in health care, education, and agriculture. Many controllers have the ability to sense the excess of electricity drawn from batteries to the load and stop the flow until sufficient charge is restored to the batteries. The latter can greatly extend the batterys lifetime. The choice of the PCU has a great impact on the performance and economics of the system. It depends on the type of waveform produced, which in turn depends on the method used for conversion, as well as the filtering techniques of unwanted frequencies.

Efficient ZV-ZCS phase shift PWM dc-dc converter interfaced with PV cell for telecommunication applications

Photovoltaic applications require regulation by high performance dc-dc converters since the dc voltage generated is normally unregulated and depends heavily on load and ambient conditions. In this paper, a ZV-ZCS full-bridge phase-shift PWM dc-dc converter is being proposed for photovoltaic cell applications. The proposed converter operates at high switching frequency with high efficiency and large power to volume ratio. A laboratory prototype model of the proposed converter has been designed and fabricated for charging a 48 V battery bank for telecommunication applications from a solar panel with 110V open circuit voltage. The experimental results were found in close agreement with the predicted soft-switching behavior of the converter.

Wind Technology and Associated Carbon Footprint

Renewable energies such as solar and wind are now widely accepted as possible future energy sources to enhance the energy demands and support the intense desire to reduce the worldwide carbon footprint. Over the last few years, renewable energy sources have won the legislative support of governments in several countries. The main reason for this boom is the need to use alternative energy sources, to fossil fuel, which are free of CO 2 emissions and contamination. Unfortunately there are no renewable energy sources that can currently account for zero carbon footprints due to the fact that it is divided into two elements direct and indirect. The direct or primary carbon footprint is related to the CO 2 emitted when burning fossil fuels in such areas as transportation and domestic energy consumption. As well as the direct carbon footprint which is universally accepted, there is also an indirect or secondary element which is associated with the life cycle of the products. The problem is how can this indirect carbon footprint be considered or included when discussing the total impact of renewable energy sources. Life Cycle Assessment is a method used to identify the main types of impact on the environment a wind turbine can cause throughout its 20 year life of operation. Emissions produced while wind turbines are in operation in addition to factors from the start of the manufacturing process to the last stage where dismantling is required at end-of-life. Life cycle assessment showed that wind turbines are not carbon neutral as they have an indirect carbon footprint. However, when compared with traditional energy sources the carbon footprint for non-traditional energy forms is still significantly limited.

UAE future electrical engineers lead in serving the community

This paper discusses the application of a service learning project in the educational process of the United Arab Emirates (UAE). Reviewed articles discussing the implementation of service learning in developed countries such as the United States of America (USA), and the United Kingdom (UK) where standards for such applications have been drafted and highlighted. The paper presents an example of service learning projects conducted in the UAE, how the project was conducted and the response of the client and students after project completion. In addition, the paper highlights various skills developed by the students during this project. Finally the paper illustrates the benefits of service learning projects in the development of the students personality, confidence and educational skills.

Chapter 3 – Photovoltaic System Conversion

This chapter discusses the conversion of solar energy into electricity using photovoltaic system. There are two types of PV systems: the grid-connected PV system and the stand-alone PV system. Solar cells are composed of various semiconductor materials that become electrically conductive when supplied with heat or light. The voltage generated by the array depends primarily on the design and materials of the cell, whereas the electric current depends primarily on the incident solar irradiance and the cell area. Photovoltaic technology is used to produce electricity in areas where power lines do not reach. In developing countries, it helps improving living conditions in rural areas, especially in health care, education, and agriculture. Many controllers have the ability to sense the excess of electricity drawn from batteries to the load and stop the flow until sufficient charge is restored to the batteries. The latter can greatly extend the battery’s lifetime. The choice of the PCU has a great impact on the performance and economics of the system. It depends on the type of waveform produced, which in turn depends on the method used for conversion, as well as the filtering techniques of unwanted frequencies.

Making Both Ends Meet: Teaching Non-Technical Skills to Engineers Using Both Content-Based Instruction and Interdisciplinary Project-Based Learning

This paper highlights key issues involved in preparing students for an engineering program in the United Arab Emirates. These students often enter the program with a limited knowledge of English and science. However, many of the challenges that they face in the course of their studies are attributable to a lack of appropriate training in non-technical skills. The paper shows how the integration of content-based instruction and interdisciplinary project-based learning can be used to enhance the acquisition of English and, at the same time, enhance other non-technical skills. This approach gives the students an early insight into the disciplinary topics covered by the university. This head start helps students make both ends meet: they achieve the required language proficiency while bolstering their content knowledge. The result of this research shows that although this method of teaching might not have been initially favored by all students and faculty, the benefits are clearly agreed upon by all parties.