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- IoT based data acquisition system
- Grid tie solar PV system
- IoT
- Losses in Solar PV plant
- Raspberry Pi
- optimum active power
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GaN Transistors for Efficient Power Conversion || Hard-Switching Topologies
摘要： In hard-switching converters, the transistors are turned on and off rapidly, while there is voltage across – and current through – the drain and source of the device. These switching transitions lead to significant power losses during the switching event. The main metrics of any converter performance are: (a) efficiency, where higher is better, (b) size, where smaller is better, and (c) cost, where lower is better. Efficiency can be increased through improvements in the switching (dynamic) and conduction (static) characteristics of the devices, thereby allowing higher switching frequencies to be used. This, in turn, leads to a size reduction, which also can lead to lower cost. In this chapter, hard-switching topologies will be reviewed and we will look at how the superior properties of GaN transistors yield significant performance improvements.
关键词： power conversion,hard-switching,efficiency,GaN transistors,switching losses
更新于2025-09-23 15:21:01
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Use of 1.7 kV and 3.3 kV SiC Diodes in Si-IGBT/ SiC Hybrid Technology
摘要： Replacing conventional Si diodes with SiC diodes in Si insulated gate bipolar transistor (IGBT) modules is advantageous as it can reduce power losses significantly. Also, the fast switching nature of the SiC diode will allow Si IGBTs to operate at their full high-switching-speed potential, which at present conventional Si diodes cannot do. In this work, the electrical test results for Si-IGBT/4H-SiC-Schottky hybrid substrates (hybrid SiC substrates) are presented. These substrates are built for two voltage ratings, 1.7 kV and 3.3 kV. Comparisons of the 1.7 kV and the 3.3 kV Si-IGBT/Si-diode substrates (Si substrates) at room temperature (20 ?C, RT) and high temperature (125 ?C, HT) have shown that the switching losses in hybrid SiC substrates are miniscule as compared to those in Si substrates but necessary steps are required to mitigate the ringing observed in the current waveforms. Also, the effect of design variations on the electrical performance of 1.7 kV, 50 A diodes is reported here. These variations are made in the active and termination regions of the device.
关键词： Hybrid substrates,Switching losses,IGBT,JTE and FLRs,Schottky diode,SiC
更新于2025-09-23 15:21:01
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[IEEE 2019 8th International Conference on Power Systems (ICPS) - Jaipur, India (2019.12.20-2019.12.22)] 2019 8th International Conference on Power Systems (ICPS) - An Efficient LLC Resonant Converter Design for Photovoltaic Application
摘要： This paper presents a novel design procedure to the LLC resonant converter for improve the ef?ciency of photovoltaic (PV) applications. State of the art LLC resonant converter operates either in buck or boost mode by operating at a switching frequency higher or lower than the resonant frequency respectively. However, such operation of the converter at a switching frequency other than the resonant frequency may result in increased turn off losses for MOSFET, conduction losses, and hard commutation for the recti?er diodes which reduces the ef?ciency of the converter. In this paper, a design procedure is proposed where the converter operates very close to the resonant frequency (10% margin) in buck and boost mode of operation to improve the ef?ciency of the converter. The design procedure mainly involves the control of the transformer tap ratio such that the converter operates near the resonant frequency. Since the transformer tap changing control is slow in nature, the proposed control strategy is mainly suited for photovoltaic application where the input voltage to the converter does not change rapidly during the daytime. The transformer tap control is suggested based on the historical data for solar energy, i.e. recorded temperature and solar irradiance. On changing the transformer tap ratio according to the input voltage, the switching frequency is observed to be moving towards the resonant frequency of the LLC resonant converter. Simulations for both the boost and buck mode operation of the resonant tank of the converter are performed, and with the proposed control higher ef?ciency is achieved for PV applications.
关键词： switching frequency,conduction losses,LLC Resonant Converter,turn-off losses
更新于2025-09-23 15:19:57
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Effects of dust, soiling, aging, and weather conditions on photovoltaic system performances in a Saharan environmenta??Case study in Algeria
摘要： Solar photovoltaic (PV) power represents one of the most promising future sources of energy in the world. Considered the cleanest form of energy, extensive research is being undertaken to widen its use. Notably, mega projects are being considered for installation in the Middle East and North Africa (MENA) region because of its high solar potential, with hopes of eventually feeding Europe from the PV electricity generated in this region and transported through high voltage direct current (DC) lines. However, current implementation of PV systems has shown that their reliability and efficiency depend upon surrounding environmental factors, such as the ambient temperature, wind, and rainfall, as well as soiling, pollution, and aging. The aim of this study was to investigate, through experimental tests, the effects of such factors on the power output of a grid connected PV station. The results showed that the output power and efficiency are deeply affected by various environmental factors, which are weather dependent. These findings may help us develop appropriate solutions to overcome these drawbacks.
关键词： Soiling,Dust,Power losses,Aging,Grid connected PV
更新于2025-09-23 15:19:57
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Multiport optical power splitter design based on coupled-mode theory
摘要： We proposed a multiport T-shaped 1 x 8 balanced optical power splitter design based on asymmetric vertical silicon slot waveguides working on the principle of coupled-mode theory (CMT). The scheme of the power splitter is unique which offers strong field confinement of TE-polarized light and delivers the light to four ports each on two opposite side of the chip. By shifting the slot towards the outer sideline of the bend, the bending losses are reduced to 80% as compared to standard symmetric slot waveguide.
关键词： coupled-mode theory,asymmetric vertical silicon slot waveguides,bending losses,TE-polarized light,optical power splitter
更新于2025-09-23 15:19:57
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Improved Coyote Optimization Algorithm for Optimally Installing Solar Photovoltaic Distribution Generation Units in Radial Distribution Power Systems
摘要： This paper proposes an improved coyote optimization algorithm (ICOA) for optimizing the location and sizing of solar photovoltaic distribution generation units (PVDGUs) in radial distribution systems. In the considered problem, four single objectives consisting of total power losses, capacity of all PVDGUs, voltage profile index, and harmonic distortions are minimized independently while satisfying branch current limits, voltage limits, and harmonic distortion limits exactly and simultaneously. The performance of the proposed ICOA method has been improved significantly since two improvements were carried out on the two new solution generations of the conventional coyote optimization algorithm (COA). By finding four single objectives from two IEEE distribution power systems with 33 buses and 69 buses, the impact of each proposed improvement and two proposed improvements on the real performance of ICOA has been investigated. ICOA was superior to COA in terms of capability of finding higher quality solutions, more stable search ability, and faster convergence speed. Furthermore, we have also applied five other metaheuristic algorithms consisting of biogeography-based optimization (BBO), genetic algorithm (GA), particle swarm optimization algorithm (PSO), sunflower optimization (SFO), and salp swarm algorithm (SSA) for dealing with the same problem and evaluating further performance of ICOA. The result comparisons have also indicated the outstanding performance of ICOA because it could find much better results than these methods, especially SFO, SSA, and GA. Consequently, the proposed ICOA is a very effective method for finding the optimal location and capacity of PVDGUs in radial distribution power systems.
关键词： voltage profile,harmonic distortions,power losses,coyote optimization algorithm,solar photovoltaic distribution generation units,radial distribution systems
更新于2025-09-23 15:19:57
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The Active Power Losses in the Road Lighting Installation with Dimmable LED Luminaires
摘要： In accordance with the requirements of PN EN 13201-5 standard for road lighting installation, energy performance indicators should be descripted. In order to calculate energy performance indicators, it is necessary to know the active power of the road lighting system. The above standard does not specify whether active power losses should be taken into account in calculations. The main purpose of the article is to estimate the active power losses in the road lighting installation. The article presents methods for calculating active power losses, taking into account losses in all main elements of the installation. The obtained calculation results show the relationship between active power losses and the power of luminaires, their number and spacing between poles. Calculations of active power losses were made for single-phase and three-phase installations. The active power losses in a three-phase system do not exceed 1.5% and in a single-phase installation they may be greater than 7%. Therefore, in order to obtain exact values of energy performance indicators (and also predict electricity consumption), active power losses should be taken into account in calculations. In addition, a comparative analysis of the effect of luminaires dimming and active power losses on annual CO2 emissions was made. Not taking into account the active power losses in the calculation of the lighting installation’s power, for single-phase installations in particular, understates the calculated value of CO2 emissions by more than 6%.
关键词： power losses,road lighting,LED luminaires
更新于2025-09-23 15:19:57
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Research into Two Photonic-Integrated Waveguides Based on SiGe Material
摘要： SiGe (Silicon Germanium) is a common semiconductor material with many excellent properties, and many photonic-integrated devices are designed and fabricated with SiGe material. In this paper, two photonic-integrated SiGe waveguides are researched, namely the SiGe-SOI (Silicon Germanium-Silicon-On-Insulator) waveguide and the SiGe-OI (Silicon Germanium-On-Insulator) waveguide. In order to verify which structure has the better waveguide performance, two waveguide structures are built, and the effective refractive indexes and the loss characteristics of the two waveguides are analyzed and compared. By simulation, the SiGe-OI optical waveguide has better losses characteristics at a wavelength of 1.55 μm. Finally, SiGe-OI and SiGe-SOI waveguides are fabricated and tested to verify the correctness of theoretical analysis, and the experimental results show that the transmission losses of the SiGe-OI waveguide are respectively decreased by 36.6% and 28.3% at 400 nm and 600 nm waveguide width in comparison with the SiGe-SOI waveguide. The results also show that the SiGe-OI waveguide has better loss characteristics than those of the SiGe-SOI waveguide at the low Ge content.
关键词： photonic-integrated,losses,SiGe material,waveguide
更新于2025-09-23 15:19:57
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Estimation of power loss spectra in slightly flattened distorted Bragg fiber waveguide
摘要： Dispersion characteristic and fiber loss spectra of a Bragg fiber waveguide having slightly flattened distortion are estimated for sensing applications. The characteristic and optical power loss equations of waveguide are obtained by matching the fields at various boundaries under quarter wave stack conditions. It is found that the optimum power loss is inversely proportional to the ninth power of distortion coefficient. The obtained results show that optimum fiber loss decreases with decrease of refractive index of cladding layer ′ ′b (low refractive index layer) and increase of refractive index of cladding layer ′ ′a (high refractive index layer). Also, fiber losses are estimated with increase of the high and low refractive index cladding layer losses. This loss spectrum of fiber can be considered as sensing signal. Since obtained fiber losses in distorted Bragg fiber are higher than standard Bragg fiber therefore, the sensitivity of proposed structure is higher than the standard Bragg fiber. Also, the sensitivity increases with the increase of refractive index of core medium. These results would be helpful to design a novel highly sensitive sensor based on hollow core distorted Bragg fiber.
关键词： Power losses,Distorted Bragg fiber,Dispersion curve,Sensitivity
更新于2025-09-23 15:19:57
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Assessment of technical and financial benefits of AC and DC microgrids based on solar photovoltaic
摘要： Microgrid deployments are expanding around the world as the most suitable solution to integrate distributed renewable energy sources to meet the increasing load demands and to power-up the remote areas. The installation of DC microgrid can improve system ef?ciency and reduces the cost of electrical infrastructure compared to the AC microgrid. However, the main challenge of implementing DC microgrid is the existing structure of the AC distribution system. In addition to the previous researches performed on DC microgrids, this paper proposes a framework to assess the technical and ?nancial bene?ts of implementing the AC and DC microgrids. The power loss, voltage drop and system ef?ciency have been investigated for the AC and DC microgrids during the steady-state condition. Furthermore, the dynamic behaviors of AC and DC microgrids have been analyzed when each system subjected to disturbance such as short-circuit fault, aiming to evaluate the system response. In the next stage, techno-economic analysis has been carried out to determine the optimal size of solar PV system connected to each AC or DC microgrid with its energy storage, according to the meteorological and load pro?le data of the selected remote area in Sarawak (Malaysia). The study presented in this paper justi?es that DC microgrid is potentially more bene?cial than AC microgrid. However, the stability of the system during fault condition is the main problem in the DC microgrid. Therefore, it can be concluded that the protection and control of DC microgrids should be the key areas of future researches.
关键词： AC and DC microgrid con?gurations,Cost optimization,Techno-economic analysis,System losses
更新于2025-09-23 15:19:57