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This paper presents a detailed study of Photovoltaic (PV) system performance under desert environmental effects in order to maximize the captured energy of PV system. The proposed study mainly focused on the output power loss of the PV system due to dust accumulation to determine the optimum tilt angle. Eight PV panels were installed on the roof of Faculty of Engineering, Upper Egypt-located in desert environment, at 15°, 20°, 30° and 45° tilt angles with the intention to analyze and compare the performance of the cleaned and dusty solar panels. The output power is recorded for cleaned and dusty solar panels with different tilt angles through the test period. Also, the effect of the panel surface temperature is experimentally studied. The measured data shows that the dust accumulation on the surface of the solar panels reduces the output power. The reduction ratio depends on the number of uncleaned days and tilt angle. The reductions in the output power for dusty panels after ten months of dust accumulation are 43%, 38%, 31%, and 25.5% for tilt angles of 15°, 20°, 30° and 45°, respectively. Also, the optimum tilt angle that gives maximum average output power depends on number of uncleaned days for the dusty panels. On the other hand, the optimum tilt angle for cleaned panels is mainly depends on the season variations. An empirical formula for the output power reduction of the solar panel is proposed and validated to illustrate the correlation between the numbers of dust accumulation days and tilt angle. It helps solar panel system designers to accurately predict the amount of solar power reduction and optimum tilt angle for a specified cleaning schedule. [ABSTRACT FROM AUTHOR]

An on chip integrated power management circuit with maximum power point tracking (PM-MPPT) control is proposed in this paper in order to achieve high efficiency Photovoltaic (PV) system. The proposed PM-MMPT circuit mitigates partial shading issues which exist in PV systems by utilizing cell-level distributed MPPT architecture, where each cell has its own MPPT circuit, in order for each cell to produce its own maximum power without affecting other cells or being affected by other cells. The proposed PM-MPPT circuit consists of two different parts. The first part is a high-efficiency synchronous power converter stage. The second part is an analog ripple correlation control (RCC) MPPT control circuit which provides faster and efficient MPP tracking, has less circuit complexity and low power consumption. HSPICE simulation model of the proposed PM-MPPT circuit is developed with a solar cell that has 0.5 V open circuit voltage and 6 A short circuit current. Simulation results show that the proposed PM-MPPT circuit rapidly tracks the MPP with a tracking efficiency larger than 99% over a wide range of irradiation levels and 92% system power conversion efficiency at a 2 W power level. The detailed analog design of the power stage and the RCC MPPT circuits are presented and discussed in the paper based on 0.35 μm CMOS technology. In addition, the PM-MMPT IC layout is presented and discussed. To validate the proposed technique and design, a comparison between the results of the proposed circuit and other reported techniques from the literature is provided. It is shown that the proposed circuit and system are able to operate with the lowest input voltage and the highest output power compared with other reported techniques. Moreover, the proposed design has the smallest size under 2 W power level. [ABSTRACT FROM AUTHOR]

In this article, a new single-stage high boosting ratio converter for grid-connected photovoltaic systems is proposed. The proposed system consists of a high voltage gain switched inductor buck-boost inverter that employs a folded cascade H-bridge circuit and operates at line frequency. The proposed system has a single switch operated with a sine wave modulation control. This applied control achieves maximum power point tracking of the input photovoltaic system in addition to the required injected sinusoidal grid current. The proposed system achieves the highest voltage boosting ratio of transformer-less topologies to the authors' best knowledge—more than ten times. In addition, it lowers switching losses and reduces the ground leakage current. A 150-W prototype with input voltage of 20 V and output voltage of 240 V has been developed with the purpose of obtaining experimental results and validating the proposed topology. Results report a boosting voltage gain of about ten times and system efficiency above 85%. [ABSTRACT FROM AUTHOR]

• Three phase dual-input split-source inverter (DSSI) is proposed for PV systems. • Compared to using one inverter for each PV source, DSSI provides reduced cost and size. • DSSI offers independent and efficient maximum power points tracking. • Experimental and simulation outcomes are presented. This paper presents a dual-input configuration for the three-phase split-source inverter (SSI) to be used with photovoltaic (PV) systems, it is denoted as DSSI. Compared to using one SSI for each PV input, the proposed configuration uses a lower number of semiconductors. Thus, lower cost along with higher power density can be acquired. The proposed DSSI inherits the brilliant features of the conventional SSI. This includes continuity of input current and high voltage boosting gain. The proposed DSSI offers independent control for the power extracted from each PV source. Thus, independent maximum power point (MPP) tracking is ensured. In addition, no circulating current between the input ports is generated. Simple modulation technique is developed for the proposed configuration. In addition, the control system design to ensure independent MPP tracking along with power quality requirements is illustrated. Comparative study with other dual-input topologies is presented. Simulation, experimental as well as real-time simulation results for DSSI are presented. The results show good performance under dual- and single-input scenarios. In addition, well dynamic performance is verified. Thus, performance at steady-state and dynamic conditions is validated for the proposed DSSI. An efficiency of 92.3 % is achieved by the experimental prototype. [ABSTRACT FROM AUTHOR]

• Dual-input split-source inverter (DSSI) is proposed for PV systems. • Compared to using one inverter per PV source, DSSI offers lower cost, and size. • DSSI offers independent and efficient maximum power points tracking. • Low capacitance value can be utilized for power decoupling. • Experimental and simulation results are provided to verify the operation of DSSI. This paper proposes dual-input configuration of split-source inverter (abbreviated as DSSI) to transfer the power of two photovoltaic (PV) modules simultaneously or individually. The proposed DSSI keeps the continuity of the input current and the voltage boosting capability offered by the conventional split-source inverter (SSI). Thus, independent as well as efficient tracking of the maximum power points (MPPs) is realized. In addition, low capacitance is utilized for power decoupling in single-phase circuits. Compared to using one SSI per PV source to feed a common load, the proposed DSSI uses lower number of switches at reduced total volt-ampere stresses. Therefore, decreased cost, size, and control circuitry are realized. Simple unipolar modulation technique is presented. Accordingly, the modes of operation and the Volt-ampere stresses of the switches are explained. A closed loop control system is explained to fulfill operation at MPP along with regulation of DC-link voltage and load current. Comparative study with other dual-input topologies is presented. Experimental results as well as real-time simulation results for dual- and single-input scenarios are presented. Also, the dynamic performance under step change in the radiation is investigated. Finally, the capability of operation under different power factors is verified. [Display omitted] [ABSTRACT FROM AUTHOR]