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Propose a MPPT Algorithm Based on Thevenin Equivalent Circuit for Improving Photovoltaic System Operation
摘要： Smart grids are considered as key solutions to solve current power security issues. Among these suggestions, microgrid is proposed to integrate distributed generations (DGs) such as photovoltaic (PV) system into the network and the control of DGs output power is getting more attention. The output power of PV arrays with nonlinear characteristics is affected by temperature, solar irradiation and load. Various maximum power point tracking (MPPT) methods for photovoltaic (PV) power systems have been considered and developed to maximize the delivered possible power. In this paper, a modelized photovoltaic source is introduced, based on the Thevenin equivalent circuit. An ordinarily employed solar system model is linearized into simple Thevenin source-resistance representation. Next, a control algorithm associated with the relationship between controller’s PWM duty cycle of the MPPT boost converter and solar array output power, namely proposed MPPT algorithm, is introduced. This proposed method is compared with an existing popular MPPT algorithm to confirm its superior performance by using the MATLAB/SIMULINK? simulation. The results show an improvement in the power generation from a PV array in any weather condition, and also help to reduce the impact of rapid change of solar irradiation on the output power variation within the time duration of change. Therefore, the proposed algorithm reduces the effect on grid frequency and motivate the PV generation penetration into the microgrids. Finally, a 50W DC-DC boost converter prototype is implemented and tested to verify the feasibility of the proposed control scheme.
关键词： photovoltaic (PV),renewable energy source,perturbation and observation method (P&O),thevenin equivalent circuit,maximum power point tracking (MPPT)
更新于2025-09-16 10:30:52
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Testing guidelines for connection of solar photovoltaic farm to distribution grid: The Malaysian experience
摘要： Solar photovoltaic technology is intermittent in nature and employs power converters for grid-interconnection, which can bring stability and power quality (PQ) issues to the power grid. Therefore, a set of testing guidelines is required to assure that solar plants comply with the grid and inverter requirements. As such, this article presents comprehensive testing guidelines for the interconnection of solar systems into Malaysian power grid, including inverter and PQ tests. The test points, conditions, parameters and acceptable limits for both tests are discussed in detail. This article also presents the results of a case study in which the testing guidelines were applied to examine the PQ of an actual grid-connected solar photovoltaic plant in Malaysia and to assess the performance of the smart inverter used in the tested solar system. The testing outcomes, which were recorded by a PQ analyser, showed that the tested solar system was in compliance with all the requirements stipulated in the testing guidelines. The findings presented in this article will help relevant parties to understand these solar testing guidelines and serve to promote the wide deployment of solar technology towards a clean and sustainable future.
关键词： testing guidelines,photovoltaic systems,power quality,renewable energy sources,inverters
更新于2025-09-16 10:30:52
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Optimal integration of microalgae production with photovoltaic panels: environmental impacts and energy balance
摘要： Background: Microalgae are 10 to 20 times more productive than the current agricultural biodiesel producing oleaginous crops. However, they require larger energy supplies, so that their environmental impacts remain uncertain, as illustrated by the contradictory results in the literature. Besides, solar radiation is often too high relative to the photosynthetic capacity of microalgae. This leads to photosaturation, photoinhibition, overheating and eventually induces mortality. Shadowing microalgae with solar panels would, therefore, be a promising solution for both increasing productivity during hotter periods and producing local electricity for the process. The main objective of this study is to measure, via LCA framework, the energy performance and environmental impact of microalgae biodiesel produced in a solar greenhouse, alternating optimal microalgae species and photovoltaic panel (PV) coverage. A mathematical model is simulated to investigate the microalgae productivity in raceways under meteorological conditions in Sophia Antipolis (south of France) at variable coverture percentages (0% to 90%) of CIGS solar panels on greenhouses constructed with low-emissivity (low-E) glass. Results: A trade-off must be met between electricity and biomass production, as a larger photovoltaic coverture would limit microalgae production. From an energetic point of view, the optimal configuration lies between 10 and 20% of PV coverage. Nevertheless, from an environmental point of view, the best option is 50% PV coverage. However, the difference between impact assessments obtained for 20% and 50% PV is negligible, while the NER is 48% higher for 20% PV than for 50% PV coverage. Hence, a 20% coverture of photovoltaic panels is the best scenario from an energetic and environmental point of view. Conclusions: In comparison with the cultivation of microalgae without PV, the use of photovoltaic panels triggers a synergetic effect, sourcing local electricity and reducing climate change impacts. Considering an economic approach, low photovoltaic panel coverage would probably be more attractive. However, even with a 10% area of photovoltaic panels, the environmental footprint would already significantly decrease. It is expected that significant improvements in microalgae productivity or more advanced production processes should rapidly enhance these performances.
关键词： Chlorococcum sp.,Renewable energy,Raceway,Desmodesmus sp.,Biodiesel,Life cycle assessment
更新于2025-09-16 10:30:52
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Feasibility and Cost Analysis of Photovoltaic-Biomass Hybrid Energy System in Off-Grid Areas of Bangladesh
摘要： In this progressing technological advancement world, hybrid systems for power generation is one of the most promising fields for any researcher. In this context, photovoltaic-biomass hybrid systems with off-grid applications have become extremely popular with both Governments and individual users in rural areas of any part of the world. This system has gained popularity because of low cost, sustainability and very effective outcome with the use of natural resources at the rural areas. In this paper a proposed hybrid system which contains photovoltaics (PV) and biomass along with an additional storage has been considered to find the different aspects from an end user point of view. It also discusses the feasibility of the proposed model for an off-grid power system located in the remote areas of Ashuganj, Bangladesh. In order to analyse the pollutant emissions and calculate the cost parameters of the proposed system, RETScreen simulation software was deployed. This research also carries out a brief financial analysis considering the annual income of the end user and the payback periods for the installed system. It endeavours to provide complete information about different parameters which also includes the environmental impacts involved in establishing the proposed system. The conventional system in the pilot area is a kerosene-based system, hence in this research, a comparison between the proposed and the conventional system has been analysed using simulated results. The simple payback of the project was estimated to be 6.9 years and this model will be able to reduce the CO2 emissions by approximately 3.81 tonnes per year. The results have significantly supported the proposed system to be more reliable, environmentally-friendly and less costly than the conventional kerosene-based system.
关键词： feasibility analysis,cost analysis,CO2 emissions,photovoltaics (PV),battery storage,renewable energy,simple payback period,biomass,off-grid electrification
更新于2025-09-16 10:30:52
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[IEEE 2019 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC) - Fukuoka, Japan (2019.7.7-2019.7.11)] 2019 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC) - Silicon waveguide polarization beam splitter using reversed ???2 coupler structure
摘要： Balancing electricity supply and demand is a complex task. Renewable energy sources are often intermittent, while electrical loads vary throughout the day. This can result in an abundant supply that suppresses spot prices in one region, while another region simultaneously experiences tight supply margins and price spikes. Connecting these two regions through electrical interconnectors would enable greater utilization of renewable energy, but this can be expensive and is unfeasible for distant regions, such as between continents. However, datacenters are becoming ubiquitous around the world and are linked through fiber connections. This paper proposes a virtual interconnector (VIC) scheme using fiber to dynamically move energy demand, in the form of computation, to datacenters in other market regions with surplus low cost and renewable energy. This increases the global renewable penetration without requiring expensive grid interconnections. The associated benefits for the datacenter operator, the electricity grid controller, consumers, and the environment are discussed.
关键词： power system economics,load management,optical interconnections,power system control,Data warehouses,renewable energy sources,green computing,power system interconnection
更新于2025-09-16 10:30:52
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[IEEE 2019 Second Balkan Junior Conference on Lighting (Balkan Light Junior) - Plovdiv, Bulgaria (2019.9.19-2019.9.21)] 2019 Second Balkan Junior Conference on Lighting (Balkan Light Junior) - Influence of the angle of fall of light on the photovoltaic panel and its optimization - literature review
摘要： Scarce energy sources in today's world are the cause of meeting energy needs in everyday life through renewable energy sources. Concerns about climate change, rising oil prices and increased government subsidies lead to enlarged investments in renewable energy sources. Today, research focuses on optimizing and improving efficiency of these sources. Renewable energy is derived from natural processes that are constantly renewed. In most of its forms it is delivered directly from the sun or from the heat accumulated in the earth. The purpose of this publication is to present a realistic approach to enhancing efficiency in cases where green energy is extracted from sun through photovoltaic panels. This would lead to a higher power supply for artificial lighting. There are significant energy losses when installing a solar panel on a static structure in the morning and late afternoon due to the fact that the panel is not sun-oriented in east-west direction (daily sun motion). There are losses also when the solar panel is not perpendicular to sun rays (in north-south direction). This publication presents the influence of the sunlight angle falling on photovoltaics and its optimization.
关键词： solar tracker,photovoltaic,green energy,solar panel,renewable energy
更新于2025-09-12 10:27:22
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Power architectures for the integration of photovoltaic generation systems in DC-microgrids
摘要： This paper describes a preliminary analysis on the integration of renewable energy systems in smart microgrids. The initial theoretical evaluations are referred to the case study of a laboratory DC microgrid interconnecting: electric mobility, stationary storage systems and renewable energy sources in a smart grid scenario. Specific power architectures for the integration of a 7kWp solar generation system with the considered microgrid are analysed and compared, in terms of efficiency and costs, in order to support the choice and the design of optimal solutions. Modeling and simulations of the related components are carried out in Matlab-Simulink environment in order to evaluate the performance of different embedded maximum power point tracking techniques, working in balanced and unbalanced irradiance conditions for the considered PV generation system. The promising results and the considerations reported in this paper highlight the importance of using the proposed smart power architectures and the related control techniques to support the optimal use of sustainable energy generation systems.
关键词： renewable energy sources,smart grids,energy storage systems,electric vehicles
更新于2025-09-12 10:27:22
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Performance of a Hybrid Solar Photovoltaic - Air Source Heat Pump System with Energy Storage
摘要： The paper introduced a smart renewable energy based microgrid system which is composed of three subsystems: solar photovoltaic subsystem, air source heat pump subsystem and energy storage subsystem. This microgrid system was applied to the demonstration project located in Xining City, Qinghai Province, China. The energy performance of the smart renewable energy based microgrid system was evaluated and compared with that of traditional energy supply system which totally depends on the electricity grid and natural gas. The comparison study demonstrates that the proposed hybrid energy supply system is superior to traditional system, significantly decreasing additional energy consumption for buildings and reducing pollutant emissions.
关键词： Energy storage,Heat pump,Solar photovoltaic,Smart microgrid,Renewable energy
更新于2025-09-12 10:27:22
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Forecasting photovoltaic and wind energy capital costs in Japan: A Bayesian approach
摘要： This study used a Bayesian approach to estimate the future capital costs of photovoltaics and wind energy in Japan. In the proposed approach, the future cost estimated by different cost estimation methods is compounded by observing actual costs during specific periods. This study used capital costs estimated in previous studies conducted after 2011 and data on the actual costs between 2015 and 2017 in Japan as input data. This study discussed the validity of this approach by comparing the compounded value with the actual cost in 2017. The result of the comparison indicates that the cost estimates obtained using the Bayesian approach are especially valid in the case wherein actual costs lie within the estimated cost range. Capital costs in 2030 are also estimated using the Bayesian approach. The probability density distribution of the capital cost in 2030 is updated to the upper side of the estimated cost range by observing the actual costs. The result obtained by this reductive approach indicates that the capital costs in 2030 are expected to lie in the upper side of the estimated cost range in Japan.
关键词： Bayesian approach,Energy policy,Renewable energy,On-shore wind,Photovoltaics,Off-shore wind
更新于2025-09-12 10:27:22
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Photovoltaic Energy Yield Improvement in Two-Stage Solar Microinverters
摘要： The focus in this paper is on the two-stage photovoltaic (PV) microinverters using a buck-boost dc/dc front-end converter. Wide input voltage range of the front-end converter enables operation under shaded conditions but results in mediocre performance in the typical voltage range. These microinverters can be controlled with either fixed or variable dc-link voltage control methods. The latter improves the converter efficiency considerably in the range of the most probable maximum power point (MPP) locations. However, the buck-boost operation of the front-end converter results in noticeable variations of the efficiency across the input voltage range. As a result, conventional weighted efficiency metrics cannot be used to predict annual energy productions by the microinverters. This paper proposes a new methodology for the estimation of annual energy production based on annual profiles of the solar irradiance and ambient temperature. Using this methodology, quantification of the annual energy production is provided for two geographical locations.
关键词： solar energy,photovoltaic,residential systems,renewable energy,variable dc-link voltage,microinverter
更新于2025-09-12 10:27:22