Browsing by Author "Alotaibi, Saud"

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A Current-Source Modular Converter for Large-Scale Photovoltaic Systems
(Saudi Digital Library, 2023-07-31) Alotaibi, Saud; Badawy, Ahmed
The world is shifting toward renewable energy sources (RESs) to generate clean energy and mitigate the stress of global warming caused by CO2 emissions in recent decades. Among several RES types, large-scale photovoltaic (LSPV) plants are a promising source for meeting ambitious clean energy targets and being part of power generation. With the progress of high-power modular inverters, new opportunities have arisen to integrate them into LSPV systems connected to medium-voltage (MV) grids to obtain high efficiency and reliability, better system flexibility, and improved electrical safety compared with string or central inverters. This thesis presents and implements a new current source three-phase modular inverter (TPMI) based on a novel dual-isolated SEPIC/CUK (DISC) converter. The TPMI is designed with a single power processing stage comprised of series- connected DISC submodules (SMs) to deliver MV into the utility grid. It outperforms conventional high-power inverters in terms of modularity, scalability, galvanic isolation compliance, and distributed maximum power point tracking (MPPT) capabilities.
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Civil liability for illegal credit card inquiries (comparative study)
(Assiut University, 2024-03-10) Alotaibi, Saud; العتيبي، سعود; عزب، حماد مصطفى; شلقامي، شحاته غريب
The credit card is one of the modern means of payment, which has achieved many advantages for all its parties. For the customer, it is a credit tool that enables him to obtain cash liquidity within a pre-determined limit. It also enables him to obtain many of the goods and services that he needs in exchange for paying for them in the form of Instalments, in addition to that, it avoids the risks of carrying money, and for the merchant, it is a means that works to increase the volume of sales, without bearing the risks that result from establishing his credit system, that is, it saves him the cost of private credit and avoids the troubles of difficult debts for customers. As for the source, the credit card is one of the means of increasing profitability, as the issuer receives interest in exchange for the credit granted to the customer. In addition to the annual renewal commission, this is in addition to the commissions it charges from the merchant according to the value of the invoice. Banks issuing credit cards also aim to obtain indirect benefits from the increase in the number of customers who deal in its name and frequent it, and then resort to it in completing their banking business. This will ultimately lead to increasing the bank's profitability, thus maximizing the owners' wealth
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INVESTIGATION OF ADVANCED SEMICONDUCTOR MATERIALS AND DEVICES FOR SOLAR CELL APPLICATIONS
(Saud Alotaibi, 2023-07-06) Alotaibi, Saud; Henini, Mohamed
High performance optoelectronic p-i-n devices based on dilute nitride GaAsPN and InGaP have been fabricated and investigated as promising III-V semiconductor materials of choice for space and photovoltaic applications due their large direct band gaps and superior radiation resistance. However, there are several factors that can introduce defects in semiconductors, including growth methods, growth conditions, substrate orientation and structure design. These defects may affect the semiconductor properties and cause severe degradations in the device performance. For solar cell applications both impurities and crystalline defects have a detrimental effect on device efficiency. Hence, identification of the defects created during the growth of materials and/or processing of these devices is necessary to gain an insight into the performance of the devices. This work investigated three sets of p-(i/n/p)-n based solar cell heterostructures and the effects on their electrical, optical and structural properties of (i) the growth conditions, namely P/Ga flux ratio (5 and 21), and rapid thermal annealing (RTA) of p-GaAs0.1P0.89N0.01 epilayers grown by molecular beam epitaxy on n-type GaP substrates, (ii) the GaAs substrate orientation (exact (100) and 20 off towards (111)B p-type GaAs substrates and doping of In0.52Ga0.48P (i-layer is either undoped and n-doped) grown by metalorganic chemical vapour deposition (MOCVD), and (iii) the GaAs misorientation angles, namely on-axis (100) semi-insulating GaAs, 2° off, 6° off, 10° off, of p-In0.52Ga0.48P grown by MOCVD. Several techniques, including atomic force microscopy, photoluminescence spectroscopy, Raman spectroscopy, Current-Voltage, Capacitance-Voltage, conventional DLTS, Laplace DLTS and ii Solar Simulator were used to study their surface morphology, optical, electrical and photovoltaic properties. The results showed that (i) the p-GaAs0.1P0.89N0.01 sample grown with a flux ratio of 5 exhibits superior electrical properties and lower defect density compared to the sample grown with a flux ratio of 21, (ii) n-doped In0.52Ga0.48P grown on exact (100) GaAs substrate exhibits better electrical properties with a lower ideality factor and reduced trap concentrations than the undoped and n-doped In0.52Ga0.48P samples grown on exact (100) and 20 off towards (111)B GaAs substrates, respectively, (iii) the p-In0.48Ga0.52P sample grown on exact (100) GaAs substrate demonstrates better electrical and photovoltaic properties compared to samples grown on misorientated wafers.
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