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- 实验方案
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[IEEE 2019 International Power System Conference (PSC) - Tehran, Iran (2019.12.9-2019.12.11)] 2019 International Power System Conference (PSC) - Optimal model predictive control of photovoltaic plants for frequency regulation in an interconnected power system
摘要： Due to growing development of photovoltaic (PV) plants in power systems, they are capable to provide ancillary service for frequency regulation. PV plants provide the required reserve of generation through operating below the maximum power point tracking. This paper proposes a model predictive control (MPC)-based approach for power control of PV plants contributing towards load frequency control (LFC). In MPC, the control signals are provided through optimizing a cost function which includes the plant model as well as current and past signals of the system. Since the successful performance of the controller depends on the well-adjusting of its weights, the weights of the controller are regulated by sine cosine algorithm to earn an optimal performance. Comprehensive discussions are presented on a three-area interconnected power system. The effectiveness of the proposed scheme is demonstrated through case studies and thereby relevant conclusions are drawn.
关键词： Load frequency control,model predictive control,photovoltaic plants,sine cosine algorithm
更新于2025-09-23 15:21:01
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Spatial modeling for the optimum site selection of solar photovoltaics power plant in the northwest coast of Egypt
摘要： The unbalanced distribution of the Egyptian population causes serious social and economic problems. Redistributing population density to fully utilize the uninhabited areas like desert regions is very critical. This requires discovering renewable energy and water resources, to achieve an optimal goal of the sustainable national strategy. Therefore, this paper aims to define the most suitable locations for establishing the photovoltaic (PV) power plants considering the techno-economic and environmental conditions, assuring the maximum power achievement with minimizing project cost. To achieve this, the integration of Geographic Information System (GIS) tools, Remote Sensing technology (RS) with the Multi-Criteria Decision Making (MCDM) technique was performed. Among MCDM techniques, the Analytic Hierarchy Process (AHP) method has been used to determine the weights of the multi-criteria (techno-economic and environmental) as a more suitable tool to solve site selection problems. The obtained results showed that the entire region's surface receives a large amount of radiation, as the maximum and the minimum values of solar radiation for 2018 were 5.9 - 4.7 kWh/m2/day, respectively. The Land Suitability Index (LSI) map was created to evaluate the potentiality of the sites. LSI was classified into five categories: “most suitable,” “highly suitable,” “moderately suitable,” “marginally suitable,” and “least suitable”. As a result, 24.9 % (261.1747 km2) of the investigation area is more suitable and promising for deploying photovoltaic (PV) power plants.
关键词： Multi-Criteria Decision Making,Egypt,Photovoltaics power plants,GIS,Remote Sensing
更新于2025-09-23 15:21:01
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Techno-economic optimization of grid-connected, ground-mounted photovoltaic power plants by genetic algorithm based on a comprehensive mathematical model
摘要： The increasing penetration of photovoltaic (PV) technology calls for the development of an effective method for optimization of grid-connected photovoltaic power plants. This paper presents a simultaneous optimization method of ten important design parameters of a PV plant, including the module power, inverter sizing, support structure dimensions, cable losses, module orientation and row spacing. A mathematical PV performance model taking into account the important effects and losses and an economic cost model were developed and presented in detail. The objective function is the internal rate of return and the optimization is performed by a genetic algorithm. The results show that the proposed models and method are capable to optimize the grid-connected PV plant and provide reliable results after a 6–7 min calculation time. The method was demonstrated in detail for a Hungarian location, including the losses and cost structure of the optimal plant configuration. The optimization was also performed for 5 additional sites around the world to assess the effect of location and meteorology. The impact of the decreasing PV module prices on the optimal design is calculated to identify the expected future trends in PV plant design. The presented optimization method can be utilized to facilitate the optimal design of commercial PV plants and for research purposes.
关键词： Modeling,Optimization,Genetic algorithm,Grid-connected photovoltaic plants
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE 14th International Scientific and Technical Conference on Computer Sciences and Information Technologies (CSIT) - Lviv, Ukraine (2019.9.17-2019.9.20)] 2019 IEEE 14th International Conference on Computer Sciences and Information Technologies (CSIT) - Method of optimizing the parameters of the photovoltaic solar power plant regime
摘要： A mathematical model of the energy-active elements of an industrial solar power plant by the photoelectric converters has been provided. A method for determining the parameters of the optimal spatial configuration of the solar power plant has been developed. The energy potential of the direct and scattered solar radiation, which has been defined using statistical data for specific geographic coordinates, energy and structural parameters of solar power plant elements refer to the input data. The optimization of spatial parameters has been carried out using a gradient method. The obtained results will allow to specify the parameters of solar power regimes and algorithms for controlling energy dynamical regimes.
关键词： input data,photoelectric battery,solar power plants,gradient method
更新于2025-09-23 15:19:57
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Rapid quality control of medicine and food dual purpose plant polysaccharides by matrix assisted laser desorption/ionization mass spectrometry
摘要： With the multiple biological activities and health benefit effects, polysaccharide in medicine and food dual purpose plants (MFDPPP) has been extensively applied in many fields, such as medical treatment, stock farming, and cosmetic industry. However, up to date, quality issues of MFDPPP and analytical technologies of polysaccharide post challenges to chemists. Reported herein is a rapid and high-throughput quality control method for analyzing MFDPPP, based on the matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS). For the analysis of illegal addition and doping, ferroferric oxide nanoparticles was screened out as MALDI matrix to avoid the small molecule interference. Qualitatively, high sensitivity was obtained for both illegal drugs and glucose. Quantitatively, the best linear response (R2 > 0.99) was attained at the concentration range from 0.005 to 1 mg·mL-1 for glucose as an example. For the analysis of polysaccharides, 2,5-dihydroxybenzoic acid/N-methylaniline was employed as MALDI matrix to increase the detection sensitivity and mass range coverage. Furthermore, the established method was successfully applied to the analysis of supplements from Astragalus polysaccharides and Lentinan real samples, respectively, thus showing its potential in quality control for MFDPPP.
关键词： medicine and food dual purpose plants,MALDI-MS,illegal adulterations,quality control,polysaccharides
更新于2025-09-23 15:19:57
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Correlations between lignin content and structural robustness in plants revealed by X-ray ptychography
摘要： Lignin is a heterogeneous aromatic polymer responsible for cell wall stiffness and protection from pathogen attack. However, lignin represents a bottleneck to biomass degradation due to its recalcitrance related to the natural cell wall resistance to release sugars for fermentation or further processing. A biological approach involving genetics and molecular biology was used to disrupt lignin pathway synthesis and decrease lignin deposition. Here, we imaged three-dimensional fragments of the petioles of wild type and C4H lignin mutant Arabidopsis thaliana plants by synchrotron cryo-ptychography. the three-dimensional images revealed the heterogeneity of vessels, parenchyma, and fibre cell wall morphologies, highlighting the relation between disturbed lignin deposition and vessel implosion (cell collapsing and obstruction of water flow). We introduce a new parameter to accurately define cell implosion conditions in plants, and we demonstrate how cryo-ptychographic X-ray computed tomography (cryo-PXCT) provides new insights for plant imaging in three dimensions to understand physiological processes.
关键词： lignin,structural robustness,X-ray ptychography,cryo-PXCT,plants,Arabidopsis thaliana
更新于2025-09-23 15:19:57
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Performance Problem of Current Differential Protection of Lines Emanating from Photovoltaic Power Plants
摘要： The amplitude and phase angle of the fault current in photovoltaic power plants (PVPPs) are significantly influenced by the control system of the grid-connected inverters, unlike in a conventional synchronous source. Hence, PVPPs may adversely affect the performance of the current differential protection designed for synchronous sources-based power grids. In order to study the performance problem of current differential protection on AC transmission lines, an analytical expression of the fault current in the PVPPs was deduced, and the fault current characteristic was extensively analyzed. Based on this analysis, the ratio of differential current over restraint current was initially derived in this study; this ratio is observed to be affected by the control system parameters, power grid system parameters, fault resistance, and fault types. Moreover, the dynamic characteristics of this ratio can be clearly observed based on a three-dimensional diagram. Furthermore, the operating performance of the current differential protection was analyzed under different influencing factors. The mathematical analysis presents that the amplitude ratio of the fault current on both sides of the line is larger than nine and that current differential protection will operate reliably in any case. Meanwhile, the theoretical analysis and simulation results show that the current phase angle difference may become an obtuse angle in case of an ungrounded fault, which will cause inaccurate operation of the current differential protection. The results of this study will provide guidance for the engineering application of current differential protection in case the PVPPs are connected to a power grid.
关键词： performance problem,photovoltaic power plants,current differential protection,fault current behavior
更新于2025-09-23 15:19:57
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[IEEE 2018 International Conference on Electrical Engineering and Computer Science (ICECOS) - PANGKAL PINANG, Indonesia (2018.10.2-2018.10.4)] 2018 International Conference on Electrical Engineering and Computer Science (ICECOS) - Comparative Analysis of Applications Off-Grid PV System and On-Grid PV System for Households in Indonesia
摘要： In Indonesia, about 89.75% of all power stations use fossil fuels, and only 10.25% generation uses renewable energy, i.e., hydropower generation, geothermal power, solar power and wind power. The use of fossil fuels such as coal, oil, and gas will cause environmental degradation. To help reduce environmental degradation requires the use of renewable energy such as solar energy through power plants in large quantities. In this paper will discuss solar power technically and economically, in this case, the cost of generation per kWh for each solar generating scheme is rooftop Off-grid photovoltaic (PV) system and on-grid PV system. Two schemes were created to calculate the generation cost per kWh for off-grid and grid-connected PV systems based on component prices for several cities in Indonesia. Electricity generation cost per kWh for off-grid PV systems and grid-connected PV system are respectively 4,644 IDR/kWh and 1,244 IDR/kWh compared to PLN electricity tariff is 1,467.28 IDR/kWh.
关键词： off-grid PV system,on-grid PV system,Solar Power Plants
更新于2025-09-19 17:15:36
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Rapid determination of mercury in dust emission using Cold Vapour Inductively Coupled Plasma Optical Emission Spectrometer (CV ICP OES)
摘要： Mercury emissions generated by the human activities were ranged between 60% and 90% from total mercury content determined in some industrialised regions. It is well known that urban dust has adverse health effects, being related to respiratory diseases. In this study, Cold Vapour Inductively Coupled Plasma Optical Emission Spectrometer (CV ICP OES) was optimised, validated, and applied in routine analysis for the determination of vapour mercury in dust emission samples collected from different Egyptian cement plants. The estimated detection limit, practical quantification limit, linearity (linear dynamic ranges and method linearity), accuracy (trueness and precision), and measurement uncertainty parameters were studied under optimised (CV ICP OES) conditions. The method showed that the estimated detection limit was found to be equal to 0.12 μg/L, and the quantification limit was found to be equal to 0.5 μg/L. The mean recoveries ± standard deviations at different levels were varied between 88.60 ± 8.18 and 110.20 ± 5.93% with a coefficient of variation expressed as relative standard deviation ranged from 0.64 and 7.25%. The method trueness was confirmed by using four different certified references materials purchased from Food Analysis Performance Assessment Scheme (FAPAS) and all obtained results were within satisfactory ranges and had acceptable recovery and Z-score values. The method precision, in terms of relative standard deviation (RSD), was being below 7.74%. The method uncertainty expressed as expanded uncertainty was found to be ≤ 16.11%. The results obtained make the method suitable for accurate determination of vapour mercury in dust emission samples at low concentration. The validated method was used for the determination of mercury in fifty-eight dust emissions samples and the results were compared with the maximum limit stated by European standard on the incineration of waste.
关键词： CV ICP OES,cement plants,mercury,Method validation,Egypt
更新于2025-09-19 17:13:59
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Frequency support from photovoltaic power plants using offline maximum power point tracking and variable droop control
摘要： With higher penetration of converter-connected renewable energy sources (RES) into power systems, the successful operation of the system is challenged by significant reductions in system inertia. Presently, given the dominant share of the conventional synchronous power plant, RES power plants are not demanded to provide ancillary services. However, as RES connections increase, RES power plants will play a major role in power system operation, contributing to frequency control. This study demonstrates that photovoltaic power plants (PVPPs) can provide effectively different types of frequency support based on a power reserve and an offline maximum power point tracking (MPPT) technique. An innovative method to de-load the PVPP without significantly increasing the MPPT complexity is proposed. Results from different PVPP frequency support methods, under varying levels of photovoltaic penetration, are presented which demonstrate their capability to provide inertia support comparable to that of synchronous generators. A new variable droop control method, which releases maximum power during the inertial response and returns to fixed droop gain value after a specified time is also presented. The results from using the variable droop show that the frequency nadir and the rate-of-change-of-frequency can be significantly reduced and some power reserve still maintained after a frequency event.
关键词： variable droop control,offline maximum power point tracking,photovoltaic power plants,system inertia,frequency support,renewable energy sources
更新于2025-09-19 17:13:59