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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Thermally-Induced Nonlinear Spatial Shaping of Infrared Femtosecond Pulses in Nematic Liquid Crystals
摘要： This paper presents a fully synthesizable phase-locked loop (PLL) based on injection locking, with an interpolative phase-coupled oscillator, a current output digital-to-analog converter (DAC), and a fine resolution digital varactor. All circuits that make up the PLL are designed and implemented using digital standard cells without any modification, and automatically Place-and-routed (P&R) by a digital design flow without any manual placement. Implemented in a 65 nm digital CMOS process, this work occupies only 110 μm × 60 μm layout area, which is the smallest PLL reported so far to the best knowledge of the authors. The measurement results show that this work achieves a 1.7 ps RMS jitter at 900 MHz output frequency while consuming 780 μW DC power.
关键词： standard cell,digital varactor,small area,low power,gated injection,injection-locking,dual loop,PLL,synthesizable,logic synthesis,edge injection,low jitter,PVT,AD-PLL,DAC,CMOS
更新于2025-09-19 17:13:59
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Design guidelines for edge-coupled waveguide unitravelling carrier photodiodes with improved bandwidth
摘要： This paper presents a fully synthesizable phase-locked loop (PLL) based on injection locking, with an interpolative phase-coupled oscillator, a current output digital-to-analog converter (DAC), and a fine resolution digital varactor. All circuits that make up the PLL are designed and implemented using digital standard cells without any modification, and automatically Place-and-routed (P&R) by a digital design flow without any manual placement. Implemented in a 65 nm digital CMOS process, this work occupies only 110 μm × 60 μm layout area, which is the smallest PLL reported so far to the best knowledge of the authors. The measurement results show that this work achieves a 1.7 ps RMS jitter at 900 MHz output frequency while consuming 780 μW DC power.
关键词： standard cell,digital varactor,small area,low power,gated injection,injection-locking,dual loop,PLL,synthesizable,logic synthesis,edge injection,low jitter,PVT,AD-PLL,DAC,CMOS
更新于2025-09-19 17:13:59
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Artificial neural network based assessment of grid-connected photovoltaic thermal systems in heating dominated regions of Iran
摘要： In this paper, an artificial neural network (ANN) is developed to assess hybrid photovoltaic thermal (PVT) systems for grid-connected (GC) electricity generation, space heating and domestic hot water providing in heating dominated regions of Iran. To do so, monthly and annual performance of a 5 kWp GCPVT system is simulated for a single-family house. The simulation results show that the GCPVT system is very promising whereas the annual yield factor varies from 1506 kWh/kWp to 1891 kWh/kWp. Also, an appropriate solar fractions for covering hot water are achieved in a range from 74.5% to 49.4%. A multilayered perceptron feed-forward neural network which is trained by Levenberg-Marquardt algorithm is used to predict AC electrical energy and solar thermal output of the GCPVT system. The developed ANN is based on global horizontal irradiance, ambient temperature, ambient relative humidity and wind speed as inputs. The proposed configuration of ANN presents a high accuracy in predicting output energy of the GCPVT system according to minimum mean square error and maximum correlation coefficient. Analysis of variance is performed to determine the significant control parameters influencing the output energy of the GCPVT system.
关键词： Solar heating,AC electricity,Grid-connected PVT,Artificial neural network,Performance assessment
更新于2025-09-19 17:13:59
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Methods for the development and testing of polymeric hybrid photovoltaic thermal (PVT) collector for indoor experiments
摘要： The purpose of this article is to present the methods for the development and testing of polymeric hybrid Photovoltaic Thermal (PVT) collectors for indoor experiments. Polymeric material has been used in hybrid PVT collectors and even longer used on flat plate collectors. We have developed a method to make a hybrid PVT collector with an absorber made of a polymethyl-methacrylate (PMMA) and combined with a copper sheet. To understand the details of the thermal and electrical performance, we have developed a method to test this PVT collector by conducting a series of experiments by varying the mass flow rate, irradiance, and inlet water temperature. The results showed that PMMA as a thermal absorber with a copper sheet can provide a beneficial cooling effect of around 80% thermal efficiency and a 0.03 %/oC decrease in electrical efficiency. This method makes PVT collector hybrids easily and cheaply using simple equipment.
关键词： Polymeric material,PMMA,The method for testing PVT collector,PVT collector,The method for development PVT collector,Indoor testing
更新于2025-09-16 10:30:52
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[IEEE 2019 3rd International Symposium on Multidisciplinary Studies and Innovative Technologies (ISMSIT) - Ankara, Turkey (2019.10.11-2019.10.13)] 2019 3rd International Symposium on Multidisciplinary Studies and Innovative Technologies (ISMSIT) - Use of Hybrid Photovoltaic-Thermal (PV/T) Solar Modules for Enhancing Overall System Efficiency
摘要： Hybrid Photovoltaic/Thermal systems, also called as PV/T systems or solar cogeneration systems, are innovative power generation technologies that convert solar radiation into usable thermal and electrical energy. Such systems combine a solar cell, which convert sunlight into electricity, with a solar thermal collector, which captures the remaining energy and removes waste heat from PV module. PV/T systems have a greater overall performance than the PV systems and solar thermal systems separately. In order to improve the performance of PV/T systems a lot of the studies have been done and researchers still keep on investigating these systems. A comprehensive review on these previous research studies are presented here. Many methods and approaches to enhance the performance of the PV/T systems are discussed along with the mathematical models used. The gaps in existing literature are identified and recommendations for future research are precisely outlined. It is emphasized here that only few experimental studies on PV/T systems based nanofluid materials are exist. Therefore, comprehensive experimental studies under real atmospheric conditions should be done with these systems, without neglecting effects of variations in mass flow rate of nanofluids,
关键词： PV hybrid,PVT,Solar energy,PVT-PCM,renewable energy
更新于2025-09-16 10:30:52
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Development of a photovoltaic thermal facade system
摘要： A photovoltaic thermal (PVT) collector is made of a photovoltaic (PV) module and a solar thermal collector and thereby delivers electrical and thermal energy at the same time. These systems can contribute significantly to the renewable energy supply of residential, public, and commercial buildings. This paper gives insight into the development of a facade-integrated PVT system within the research project PVT Fassade. Thermal simulations evaluated useful operating conditions and efficiency-decreasing factors. Thus, 10 kg/(hm2) and 60 kg/(hm2) were identified as lower and upper limits for the mass flow and the losses by the internal heat transfer resistance of a 3.5 mm air layer between the PV module and the heat exchanger were determined to 35 % and 48 % for 10 and 60 kg/(hm2). These findings and structural, aesthetical, and general building law requirements were taken into consideration for the design of the facade-integrated PVT system. The functionality and feasibility of the developed system is shown through a constructed prototype facade where an intensive monitoring of the thermal and electrical performance of the PVT system is conducted. The performance of the PVT facade collector is described on the basis of an exemplary day of this monitoring. On this day, an area-specific thermal yield of 4.13 kWh/m2 with a temperature spread of up to 10.7 K is reached. At the same time, the thin film PV modules of the PVT system achieve an electrical yield increase of 2.5 % compared to a reference PV facade system.
关键词： facade-integrated PVT system,electrical yield,thermal simulations,photovoltaic thermal (PVT) collector,renewable energy
更新于2025-09-16 10:30:52
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Hybrid Photovoltaic and Solar Thermal Systems (PVT): Performance Simulation and Experimental Validation
摘要： Continuous Solar irradiation on the photovoltaic panel causes its temperature to increase, resulting in reduced efficiency. The present paper focuses on improving the efficiency of the photovoltaic panel through the use of hybrid Photovoltaic-Thermal (PVT) system. Water is used as the coolant in the cooling channel, flowing through the copper tubing provided below the photovoltaic panel, where the temperature is maximum. The thermal energy extracted in the process can be harnessed in several ways, improving the overall efficiency of the system. A theoretical model was prepared using COMSOL? multi-physics. The results achieved in the experimental set-up are quantified. As per the experimentation carried on the photovoltaic panel, an average temperature of 303.38 K at Standard Test Condition (STC) was achieved through cooling, while the temperature of the panel without cooling rose up to 333.15 K in environmental conditions, thus, improving the efficiency of the photovoltaic panel. The paper later applies the idea to an entire solar power plant to improve the overall efficiency of the power plant, by cooling the photovoltaic panel as well as generate hot water as its by-product.
关键词： Hybrid photovoltaic-thermal (PVT) systems,Hybrid model,Photovoltaic panel
更新于2025-09-16 10:30:52
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Study of hybrid photovoltaic thermal systems
摘要： Sun is the primary source of renewable energy. It is abundant, inexhaustible and clean. It plays a very important role in the present energy crisis. Solar energy can be harnessed by hybrid photovoltaic thermal system to generate power and heat. These devices generate thermal and electrical energy simultaneously. Hybrid photovoltaic thermal systems have high efficiency. There is ample scope in this area as much work remains to be done. The hybrid system has huge potential in India where the availability of solar energy is spread throughout the country. The paper focusses on the study of hybrid photovoltaic thermal systems.
关键词： Photovoltaic thermal,PVT performance,Hybrid solar
更新于2025-09-16 10:30:52
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Empirical influence of various environmental conditions and mass flow rates on hybrid photovoltaic thermal modules
摘要： Environmental conditions and mass flow rates both influence the performance of hybrid photovoltaic thermal modules. In this work, the performance of a photovoltaic thermal module was investigated under two controlled laboratory environmental conditions: closed and ventilated air circulation. Comparing two different environmental conditions, we have examined the effect on operating temperature by the mass flow rate of coolant, varied over the range 0.05 kg/s to 0.10 kg/s. Experimental results, under indoor laboratory conditions, indicate there is a measurable effect from mass flow rate on the overall electrical efficiency in comparison to output at ambient temperature. Interestingly, the output power and electrical energy of the photovoltaic thermal module were observed to increase by 6.06 % and 3.67 %, respectively, under the conditions of ventilated air circulation. In addition, the maximum electrical and thermal efficiencies of the photovoltaic thermal module were estimated as 13.67 % and 53.08 %, respectively. Results obtained in this study provide a useful reference for applications of PVT modules requiring combined heat and power, such as commercial buildings and building integrated design.
关键词： Mass flow rate,Environmental condition,PVT module,Performance.
更新于2025-09-16 10:30:52
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AIP Conference Proceedings [AIP Publishing RENEWABLE ENERGY SOURCES AND TECHNOLOGIES - Tamil Nadu, India (14–15 March 2019)] RENEWABLE ENERGY SOURCES AND TECHNOLOGIES - Performance investigation on various models on solar photovoltaic thermal (PVT) hybrid system
摘要： This research article deals with the first law of thermodynamic analysis on solar photovoltaic thermal hybrid system with three kinds of models namely model 1 (fully transverse obstacles), model 2 (partially transverse obstacles) and model 3 (longitudinal obstacles with baffles) experimentally. It was designed, fabricated and tested at the tropical climatic condition of Chennai. Two different mass flow rates of air (0.0071 kg/s and 0.0085 kg/s) have been used for enhancing the performance of the system. The performance of solar PVT hybrid system relies on solar radiation, physical geometry and mass flow rate of air. All the models were subjected to first law analyses which were compared with respect to local time and other parameters such as glazing temperature, outlet air temperature. The PVT hybrid system experimentally proved to enhance the thermal performances with an increasing air mass flow rate. The obtained experimental results are in good agreement with previous research findings.
关键词： PVT,photovoltaic thermal,model,thermal efficiency,obstacles
更新于2025-09-16 10:30:52