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One way to increase the energy amount obtained from renewable sources is to improve their efficiency. This study analyses the influence of hybridization upon the monocrystalline silicon and Maxeon photovoltaic cells temperature... more
One way to increase the energy amount obtained from renewable sources is to improve their efficiency. This study analyses the influence of hybridization upon the monocrystalline silicon and Maxeon photovoltaic cells temperature distribution and its variation in days with clear and cloudy sky. Three photovoltaic cells for each type mentioned before are measured. Two of them, connected in series, are part of photovoltaic/thermoelectric generators/solar collector hybrid system, which are cooled, and the third is uncooled and mounted on the same plane with the other two. The maximum power and the efficiency gain for both types of photovoltaic cells are performed and analyzed in different conditions using a fixed system and a sun tracker system as support for the hybrid system. The advantages of the temperature decrease are also discussed.
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The performance of the hybrid structures PV/TEG/STC which consist of photovoltaic cells PV, thermoelectric elements TEG and solar collector STC is studied in this paper function of different levels of illumination from 30 suns to 130 suns... more
The performance of the hybrid structures PV/TEG/STC which consist of photovoltaic cells PV, thermoelectric elements TEG and solar collector STC is studied in this paper function of different levels of illumination from 30 suns to 130 suns (1 sun = 1000 W/m2). The concentrated light is obtained using a solar simulator with four parabolic xenon lamps and an optical mixer to ensure the quasi homogenous illumination of the hybrid system. The important parameters of the photovoltaic cells and of the thermoelectric generators are determined using the current-voltage characteristics. The measurements and control are realized using the NI-cRIO platform and the software is developed in LabVIEW.
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The quick progress in solar energy technology has made it one of the most promising alternatives to conventional energy systems in recent years. In this work, in order to make efficient use of the solar energy, a hybrid system composed of... more
The quick progress in solar energy technology has made it one of the most promising alternatives to conventional energy systems in recent years. In this work, in order to make efficient use of the solar energy, a hybrid system composed of the concentrated photovoltaic cell and thermoelectric generator (CPV-TEG) is studied using both experimental and numerical approaches. The experimental study is carried out under concentrated radiation of a solar simulator, and the numerical simulation is accomplished using finite volume method. The results are presented for various solar concentration (SC) values ranging from 8 suns to 37 suns. The variation of the temperatures, open circuit voltage, and short circuit current are discussed. I-V-P curves for both CPV and TEG are obtained and evaluated experimentally and numerically. The results show that contribution of the TEG in the total electrical power produced by the hybrid system enhances with increasing the solar radiation. Furthermore, the experimental results indicate that the maximum and minimum efficiency of the CPV is reached to 35.33% and 23.02%, while these values for the TEG are 1.20% and 0.63%, respectively.
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During field operation, photovoltaic cells (PVs) are often subject to rapid variations in incident light, due to fast moving clouds. This causes variations in the operating temperature of the PVs as well. In this work we study the effect... more
During field operation, photovoltaic cells (PVs) are often subject to rapid variations in incident light, due to fast moving clouds. This causes variations in the operating temperature of the PVs as well. In this work we study the effect of rapid concentrated light variation over the PVs as an ageing method. The irradiance and thermal cycles were performed using a self-developed system with a controlled shutter that modulates the highly concentrated light incident on the PVs. Through the load we developed based on the impedance variation of a capacitor and a coil during the charge/discharge process, the main DC and AC parameters of the PVs are monitored in-situ through the I-V characteristics and RLC method measurements. Preliminary results show a degradation of 0.6% of the PVs caused by the light and temperature stress.
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This paper describes a model and its PSPICE simulation for a hybrid electric generator that is composed of a photovoltaic cell and a thermoelectric generator. The focus is to combine both models to obtain a hybrid system model. The... more
This paper describes a model and its PSPICE simulation for a hybrid electric generator that is composed of a photovoltaic cell and a thermoelectric generator. The focus is to combine both models to obtain a hybrid system model. The electrothermal models of the photovoltaic cell and thermoelectric generator are described. The simulations are done using the NI Multisim electronic circuit simulators. The comparison between the results obtained through simulation and through real measurements on commercial PV and thermoelectric generators is also presented.
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The demand of energy increases once with the growth of population, and therefore, the finding of or improvement in the efficiency of renewable energy sources becomes very important for researchers and industry. The conversion of solar... more
The demand of energy increases once with the growth of population, and therefore, the finding of or improvement in the efficiency of renewable energy sources becomes very important for researchers and industry. The conversion of solar energy into electrical energy can be done based on photovoltaic or Seebeck effects. In the first case, photovoltaic panels are used, while in the second case, thermoelectric generators are used. The two can be combined to obtain the so-called hybrid systems, which have the goal to improve the overall conversion efficiency of the system. This chapter is focused on showing how the graphical programing language, called NI LabVIEW, together with a SPICE simulator, called NI Multisim, can be used for studying and understanding the behavior of the photovoltaic and thermoelectric generators as parts of the renewable energy sources. Different simulations developed in LabVIEW or Multisim are presented, and some monitoring and characterization applications are a...
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The article includes a review of some methods to determine series and shunt resistances. It also presents a new method to determine series and shunt resistances and a comparison of results to previous literature methods. The new method is... more
The article includes a review of some methods to determine series and shunt resistances. It also presents a new method to determine series and shunt resistances and a comparison of results to previous literature methods. The new method is based on the one diode model for solar cells and is applied on a c-Si cell. The dependence of the series resistance on the irradiance levels is also presented. The complex programme developed to determine the cell characterization and implicitly for the determination of series resistance is included. The programme was created in the graphical programming language LabVIEW.
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With the growth of Industry 4.0, cyber-physical systems are increasingly present in everyday life, thus optimizing traditional processes. This paper presents a solution for photovoltaic panel parameters monitoring application fully... more
With the growth of Industry 4.0, cyber-physical systems are increasingly present in everyday life, thus optimizing traditional processes. This paper presents a solution for photovoltaic panel parameters monitoring application fully integrated into an IoT system. The application can record and process sensor data such as photovoltaic (PV) panel current, voltage, illuminance level, PV temperature as well as atmospheric pressure, ambient temperature, and humidity over a long-distance solution utilizing the LoRa Wide-Area Network protocol. The Internet of Things node is designed for security, accuracy and low power consumption, while also providing an established user interface through a proprietary software as a service Live Object platform. By utilizing Live Objects, complete IoT applications can be developed with the device and data management being handled by the platform. The advancements in terms of hardware and software configuration, sensor choice and operation are described. In this way, we can create a scalable and secure Internet of Things ecosystem using low-cost and power efficient devices, integrated in a secure and easy to use software as a service (SaaS) platform.
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This paper describes a model and its PSPICE simulation for a hybrid electric generator that is composed of a photovoltaic cell and a thermoelectric generator. The focus is to combine both models to obtain a hybrid system model. The... more
This paper describes a model and its PSPICE simulation for a hybrid electric generator that is composed of a photovoltaic cell and a thermoelectric generator. The focus is to combine both models to obtain a hybrid system model. The electrothermal models of the photovoltaic cell and thermoelectric generator are described. The simulations are done using the NI Multisim electronic circuit simulators. The comparison between the results obtained through simulation and through real measurements on commercial PV and thermoelectric generators is also presented.
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Using the same PV system can lead to an increase in the output energy quantity if the solar energy input increases. This can be achieved by using a solar tracker. A comparative study between a two axes sun tracker system and a fixed one... more
Using the same PV system can lead to an increase in the output energy quantity if the solar energy input increases. This can be achieved by using a solar tracker. A comparative study between a two axes sun tracker system and a fixed one was per-formed in order to see the gain as ...
Abstract-Centrul de Valorificare si Transfer de Competenta CVTC de la Universitatea „Transilvania” din Brasov, colaboreaza de mai multi ani cu Firma Eco Chemie din Olanda http://www. ecochemie. nl, producatoarea sistemelor AUTOLAB,... more
Abstract-Centrul de Valorificare si Transfer de Competenta CVTC de la Universitatea „Transilvania” din Brasov, colaboreaza de mai multi ani cu Firma Eco Chemie din Olanda http://www. ecochemie. nl, producatoarea sistemelor AUTOLAB, dedicate masuratorilor ...
... BIBLIOGRAFIE [1] Petru Cotfas, Doru Ursutiu, Cornel Samoila, Creating a virtual lab using LabVIEW, TICE 2000 , Colloque international, Université de Technologie de Troyes, 2000; [2] P. Cotfas, D. Ursutiu, DT Cotfas, C. Samoila... more
... BIBLIOGRAFIE [1] Petru Cotfas, Doru Ursutiu, Cornel Samoila, Creating a virtual lab using LabVIEW, TICE 2000 , Colloque international, Université de Technologie de Troyes, 2000; [2] P. Cotfas, D. Ursutiu, DT Cotfas, C. Samoila Implementarea Metodei Entropei Maxime ...
Photovoltaic cells are the best known devices to convert solar energy into useful electrical energy, however, in the most efficient multijunction solar cells, more than half of the input solar energy converts into heat and wastes. In this... more
Photovoltaic cells are the best known devices to convert solar energy into useful electrical energy, however, in the most efficient multijunction solar cells, more than half of the input solar energy converts into heat and wastes. In this experimental investigation, a thermoelectric generator, as highly reliable solid-state device, and a box containing phase change material are integrated to a concentrated triple junction solar cell in order to enhance the utilization of the solar energy. The triple junction solar cell and the thermoelectric generator are characterized by measuring the I-V-P under different solar concentrations. In order to evaluate the impact of using PCM, the obtained performance of the hybrid system and the short circuit current, open circuit voltage and maximum power for its two components are compared in steady state and transient regimes with the hybrid system without the PCM. The results indicate that enhancement of the concentration ratio has opposite impact on the efficiency of the thermoelectric generator and the triple junction solar cell. Furthermore, the phase change material box has a more considerable impact on the power generated by the thermoelectric generator than the triple junction solar cell for both regimes.
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Optimization methods are finding more applications in all domains, as they play an essential role when dealing with real-life problems [...]
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In this paper, we present the implementation of a system that identifies the modulation of complex radio signals. This is realized using an artificial intelligence model developed, trained, and integrated with Microsoft Azure cloud. We... more
In this paper, we present the implementation of a system that identifies the modulation of complex radio signals. This is realized using an artificial intelligence model developed, trained, and integrated with Microsoft Azure cloud. We consider that cloud-based platforms offer enough flexibility and processing power to use them instead of conventional computers for signal processing based on artificial intelligence. We tested the implementation using a software-defined radio platform developed in GNU Radio that generates and receives real modulated signals. This process ensures that the solution proposed is viable to be used in real signal processing systems. The results obtained show that for certain modulation types, the identification is performed with a high degree of success. The use of a cloud-based platform allows quick access to the system. The user is able to identify the signal modulation using only a laptop that has access to the internet.
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The metaheuristic algorithms and their hybridization have been utilized successfully in the past to extract the parameters of photovoltaic (PV) cells and panels. The novelty of the paper consists of proposing the black widow optimization... more
The metaheuristic algorithms and their hybridization have been utilized successfully in the past to extract the parameters of photovoltaic (PV) cells and panels. The novelty of the paper consists of proposing the black widow optimization algorithm (BWOA) for the first time to identify the parameters of the two photovoltaic cells RTC France, amorphous silicon (aSi), and two photovoltaic panels PWP201, PVM 752 GaAs. The single-diode model (SDM) and double-diode model (DDM) for analyzing the PVs are considered. The performance of the BWOA is verified using four statistical tests: the root mean square error, which is the primary tool, the mean relative error, the mean bias error, and the coefficient of determination. The research results of this study are as follows: BWOA gave the same results, or very slightly better, for RTC and PWP201 for SDM in comparison with the best algorithms from the specialized literature; for all the other cases, BWOA has substantially better results, especia...
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The goal of this research is to accurately extract the parameters of the photovoltaic cells and panels and to reduce the extracting time. To this purpose, the barnacles mating optimizer algorithm is proposed for the first time to extract... more
The goal of this research is to accurately extract the parameters of the photovoltaic cells and panels and to reduce the extracting time. To this purpose, the barnacles mating optimizer algorithm is proposed for the first time to extract the parameters. To prove that the algorithm succeeds in terms of accuracy and quickness, it is applied to the following photovoltaic cells: monocrystalline silicon, amorphous silicon, RTC France, and the PWP201, Sharp ND-R250A5, and Kyocera KC200GT photovoltaic panels. The mathematical models used are single and double diodes. Datasets for these photovoltaic cells and panels were used, and the results obtained for the parameters were compared with the ones obtained using other published methods and algorithms. Six statistical tests were used to analyze the performance of the barnacles mating optimizer algorithm: the root mean square error mean, absolute percentage error, mean square error, mean absolute error, mean bias error, and mean relative erro...
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The main idea of this work was to implement the National Instruments Educational
The improvements of a test bench system for testing the solar cells is presented. The system allows measuring the I-V characteristics at different levels of lighting. Also the dynamic behavior of solar cells using light or current pulses... more
The improvements of a test bench system for testing the solar cells is presented. The system allows measuring the I-V characteristics at different levels of lighting. Also the dynamic behavior of solar cells using light or current pulses is presented.
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In light of the recent advances in the Internet of Things and embedded networking technologies, online Internet access for computing devices has been extended from classic computers and servers to virtually all embedded devices with... more
In light of the recent advances in the Internet of Things and embedded networking technologies, online Internet access for computing devices has been extended from classic computers and servers to virtually all embedded devices with minimal networking capabilities. In this context, our efforts targeted applying this approach to the field of remote learning, by transcending the infrastructure needed for a remote laboratory from mainframe servers and computers to embedded devices: FPGA/System-on-Chip (SoC). This paper describes the internal architecture of a FPGA-based SoC with its components: networking interface (including a Web Server), data acquisition interface (through the on-board Analog-to-Digital converter) and configuration and control software. Also, the article presents the implementation of the Web interface available online that provides an easily accessible, real-time interactive interface for the data visualization and control of the remote FPGA-based SoC, which enables remote access for students and faculty to perform remote experiments and data analysis.
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The recent rise and development of a variety of virtual and distance learning platforms in the field of engineering hasbrought on common downsides for most of these solutions. Among them, the difficulty in offering access to... more
The recent rise and development of a variety of virtual and distance learning platforms in the field of engineering hasbrought on common downsides for most of these solutions. Among them, the difficulty in offering access to physicalequipment in fields where a practical, hands-on approach is mandatory and also a low effectiveness in resource sharing, dueto the fact that traditionally, one hardware equipment can be used by only one student at a given moment. This paperdescribes the design and implementation of a digital hardware design remote virtual laboratory that provides solutions tothese issues. Reconfigurable hardware development platforms are made available online using Web services, thusproviding easy access for student practice by the means of an intuitive Web interface that offers the user the possibilityto remotely configure and communicate with its designated hardware resource. Another particular feature of thisimplementation is that the same development board can be shar...
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Soil measurements are important for agriculture as improper conditions can generate important losses. This paper presents a new IoT based system, created to monitor some important parameters for soil, such as solar illumination, air... more
Soil measurements are important for agriculture as improper conditions can generate important losses. This paper presents a new IoT based system, created to monitor some important parameters for soil, such as solar illumination, air temperature, air humidity, soil humidity, soil pH, and total salt content. Measurements are performed using several microcontrollers, connected to each other, status information being generated, available on the cloud. In this respect, the goal of the proposed device is to perform useful measurements for agriculture applications and provide instruments to take the proper actions.
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Some parameters must be calculated with very good accuracy for the purpose of designing, simulating, and evaluating the performance of a photovoltaic system. The seven parameters of the photovoltaic cell and panels for the two-diode model... more
Some parameters must be calculated with very good accuracy for the purpose of designing, simulating, and evaluating the performance of a photovoltaic system. The seven parameters of the photovoltaic cell and panels for the two-diode model are determined using a parallelized metaheuristic algorithm based on successive discretization. The parameters obtained for a photovoltaic cell and four panels using the proposed algorithm are compared with the ones calculated through over twenty methods from recent research literature. The root mean square error is used to prove the superiority of the Parallelized Successive Discretization Algorithm (PSDA). The smallest values for root mean square error (RMSE) in both cases, photovoltaic cell and panels, are obtained for the algorithm presented in this paper. The seven parameters for three panels known in the specialised literature, Kyocera KC200GT, Leibold Solar Module LSM 20, and Leybold Solar Module STE 4/100 are determined for the first time u...
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This paper presents the design of a system for studying photovoltaic cells PV, thermoelectric generators TEG, a solar collector SC and different hybrid structures comprising two or three of them in concentrated light. The concentrated... more
This paper presents the design of a system for studying photovoltaic cells PV, thermoelectric generators TEG, a solar collector SC and different hybrid structures comprising two or three of them in concentrated light. The concentrated light is obtained using a Fresnel lens and a sun tracker. The advantages of the system are: the reduction of the photovoltaic cells area, the use of the photovoltaic cells with high efficiency and the possibility to vary the levels of illumination up to 56 suns. The system control is achieved using the NI-cRIO and NI-myRIO embedded hardware and the software is developed in LabVIEW, using a mathematical algorithm for the sun tracker system.
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The main goal of this paper is to review the most important methods previously developed to enhance the efficiency and increase the lifetime of photovoltaic panels. The methods to increase the solar radiation incident on photovoltaic... more
The main goal of this paper is to review the most important methods previously developed to enhance the efficiency and increase the lifetime of photovoltaic panels. The methods to increase the solar radiation incident on photovoltaic panels, as well as the cooling and the maximum power point tracker methods, are concisely presented in this paper. The pros and cons analysis reveals that the methods to enhance the power generated by the photovoltaic panels are strongly dependent on geographical location, climatic conditions, and the materials used. This review paper is also of interest for engineers who attempt to identify the most adequate solutions to maximize the energy output of photovoltaic systems for each location.