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Records with Subject: Environment
Showing records 2197 to 2221 of 3422. [First] Page: 1 85 86 87 88 89 90 91 92 93 Last
A Study of Total-Factor Energy Efficiency for Regional Sustainable Development in China: An Application of Bootstrapped DEA and Clustering Approach
Yang Li, An-Chi Liu, Shu-Mei Wang, Yiting Zhan, Jingran Chen, Hsiao-Fen Hsiao
March 1, 2023 (v1)
Subject: Environment
Keywords: bootstrapped clustering approach, China, DEA, regional sustainable development, total-factor energy efficiency
Total-factor energy efficiency (TFEE) is widely used to measure energy efficiency under the data envelopment analysis (DEA) framework, but the efficiencies obtained from DEA are structurally biased upward, and thus TFEE tends to overestimate energy efficiency. This research thus applies the bootstrapped DEA approach to correct the bias of TFEE. Using a dataset consisting of 30 provinces of China in the period 2016−2019, the bootstrapped-based test supports technology with variable returns to scale. The biased-corrected TFEE also indicates that energy consumption on average can be scaled down by 42.36%, rather than the biased value of 19.4%. The bootstrapped clustering partitions provinces into three groups: Cluster 1, with Guizhou as the representative medoid, includes half of the superior coastal provinces in terms of actual energy consumption and TFEE and half of the competitive inland provinces, whereas Cluster 3 outperforms Cluster 2 in terms of TFEE, but the actual energy consumpt... [more]
Circular Economy Framework for Energy Recovery in Phytoremediation of Domestic Wastewater
Hauwa Mohammed Mustafa, Gasim Hayder, Siti Indati Mustapa
March 1, 2023 (v1)
Subject: Environment
Keywords: bioenergy, circular economy (CE), phytoremediation techniques, plant-based biomass, relative growth rate (RGR), wastewater treatment
Circular economy (CE) strategy is crucial in developing towards sustainable growth. It was created to promote resource utilization and the elimination of waste production. This article aimed to study the possibilities of using the CE framework in wastewater bioremediation and energy recovery using hydroponic tanks. The integration of phytoremediation with bioenergy, construction and lifespan of hydroponic tanks in phytoremediation of wastewater, selection of aquatic plants and the expected challenges in the implementation of CE in phytoremediation of wastewater were discussed. The plant-based biomass harvested and the relative growth rate (RGR) of the selected plants from the phytoremediation process was evaluated. The findings obtained indicated that the selected plants tripled in weight after 14 days cultivation period at different retention times. E. crassipes recorded the highest growth with 2.5 ± 0.03 g g−1 d−1, followed by S. molesta with 1.33 ± 0.05 g g−1 d−1 and then P. stratio... [more]
Dandelion-Root Extract as Green Corrosion Inhibitor for Carbon Steel in CO2-Saturated Brine Solution
Katarina Žbulj, Lidia Hrnčević, Gordana Bilić, Katarina Simon
March 1, 2023 (v1)
Subject: Environment
Keywords: carbon steel, CO2-saturated brine solution, dandelion-root extract, green corrosion inhibitor
Recently, due to the corrosion problem in the petroleum industry and the usage of commercial corrosion inhibitors, which, when released untreated into the environment, are considered to be environmentally unfriendly, green corrosion inhibitors are being researched. In this paper, the results of dandelion-root-extract testing as a green corrosion inhibitor for carbon steel in simulated brine solution saturated with carbon dioxide (CO2) are shown. The extract’s inhibition efficiency in static and flow conditions was determined by using potentiodynamic polarization with Tafel extrapolation and electrochemical-impedance-spectroscopy methods. In static conditions, the extract was tested at different concentrations. A maximum inhibition efficiency of 98.37% in static conditions at an extract concentration of 12 mL/L and 82.80% in flow conditions at a concentration of 14 mL/L was achieved. Additionally, for the most efficient dandelion-root-extract concentration (12 mL/L), the biodegradabilit... [more]
The Impact of Thermal Inertia on the Indoor Thermal Environment of Light Steel Framing Constructions
Eduardo Roque, Romeu Vicente, Ricardo M. S. F. Almeida, Victor M. Ferreira
March 1, 2023 (v1)
Subject: Environment
Keywords: indoor thermal environment, light steel framing, masonry, southern European, thermal inertia
Typically, reinforced concrete and brick masonry construction is the most common construction system of the majority of the southern European residential building stock. However, the lightweight steel framing (LSF) construction system has been progressively assuming a relevant position in the residential sector. Since LSF is not the traditional construction system, the indoor thermal environment of these buildings has not been widely studied and discussed considering the southern European climate context. The low thermal inertia of this construction system is commonly pointed to as a possible weakness in warmer climates. The present work aims to address this research gap by evaluating and comparing the LSF and masonry construction systems in terms of the indoor thermal environment focusing on the level of thermal inertia. The considered methodology lies in a long-term experimental campaign based on the construction and monitoring of two identical experimental test cells, differing only... [more]
Livestock Wastes Sustainable Use and Management: Assessment of Raw Sheep Wool Reuse and Valorization
Monica C. M. Parlato, Francesca Valenti, Giusi Midolo, Simona M. C. Porto
March 1, 2023 (v1)
Subject: Environment
Keywords: circular economy, environmental impact, GIS, livestock waste, sheep wool, spatial analysis, Sustainability
Worldwide, around 998 million tons of agricultural waste are generated yearly, including livestock wastes, which create several critical environmental issues if not properly treated. In this study, a Geographical Information System (GIS)-based model to locate and quantify both the yearly amount of livestock waste, i.e., sheep wool, and the territorial distribution of sheep farms, was carried out and applied within the selected study area. The aim was to identify those territorial areas most suitable for localizing new shared wool collection centers to sustainably manage the reuse of this waste as potential green building material. Data related to both sheep farms and sheep number and the related sheep shared wool (SSW) yearly production were acquired and applied in GIS. By GIS-based model results, two collection centers have been identified within the provinces of Agrigento and Enna. Then, to develop a sustainable reuse in terms of reducing environmental impact due to the SSW logistics... [more]
Lock-In Effects on the Energy Sector: Evidence from Hydrogen Patenting Activities
Francesca Pantaleone, Roberto Fazioli
March 1, 2023 (v1)
Subject: Environment
Keywords: Energy, environmental innovation, Hydrogen, panel data, patents, renewables
The aim of the paper is to analyze how regulatory design and its framework’s topics, other than macroeconomic factors, might impact green innovation by taking into consideration a brand-new renewable source of energy that is becoming more and more important in recent years: hydrogen and fuel cell patenting activities. Such activities have been used as a proxy for green technological change in a panel data of 52 countries over a 6-year period. A series of sectorial, energy regulation, and macroeconomic variables were tested to assess their impact on that technological frontier of green energy transition policy. As might have been expected, the empirical analysis carried out with the model that was prefigured confirms significant evidence of lock-in effects on fossil fuel policies. The model confirms, however, another evidence: countries already investing in renewables might be willing to invest in hydrogen projects. A sort of reinforcement to the further development of green sustainable... [more]
Green Intellectual Capital as a Support for Corporate Environmental Development—Polish Company Experience
Edyta Bombiak
March 1, 2023 (v1)
Subject: Environment
Keywords: environmental development, green human capital, green intellectual capital, green organizational capital, green relational capital, sustainable development
Green intellectual capital (GIC) is a distinctive intangible asset that may assist organizations in pursuing sustainable development strategies. In Polish organizations, interest in this new concept is low. Analysis of the literature showed a lack of research regarding the implementation of GIC practices or their impacts on the sustainable development of organizations in Polish enterprises. In order to fill the detected research gap, the study covered 150 randomly selected Polish enterprises. The purpose of the research was to determine the impact of activities fostering GIC on the environmental development of companies in Poland and to identify major practices supporting GIC development. In addition, the author attempted to establish a correlation between the impact of individual practices oriented at GIC formation and their practical implementations in the analyzed enterprises. The first stage of the analysis focused on identification of activities leading to the accumulation of GIC... [more]
Building Energy Self-Sufficiency of Municipalities on the Basis of National Legal Conditions in the Theoretical Perspective of the Polish Legal Experiences
Szymon Słotwiński
March 1, 2023 (v1)
Subject: Environment
Keywords: legal environment for energy decision making, local energy communities, RES
In today’s social, economic, and political reality, it cannot be overlooked that the energy self-sufficiency of municipalities not only optimizes the lives of the inhabitants of the municipality but also, in a broader perspective, the services provided by the municipality. The sustainable development of a municipality will therefore depend on its degree of self-reliance and self-sufficiency. Economic and technological considerations are not sufficient for the municipality to achieve optimal energy independence without normative conditions. The current (2021/2022) trends in electricity prices and in the development of national and international policies and strategies for electricity generation from renewable energy sources also make the change in the energy market structure toward distributed generation. The main objective of this paper is a theoretical analysis of the legal solutions in force in Poland that allow building energy self-sufficiency in municipalities and their adequacy to... [more]
Pathway to Green Transformation in Lithuania: Biogas Production from Manure and Waste
Živilė Gedminaitė-Raudonė, Rita Lankauskienė, Vitalija Simonaitytė
March 1, 2023 (v1)
Subject: Environment
Keywords: biogas production, circular bioeconomy, development pathway, European Green Deal, green transformation, Lithuania, stakeholders, sustainability transition
Green transformation at the beginning of the 21st century occupies the top positions in modern society’s sustainability transition research and policy debates due to its multiple propositions of various innovations, addressing the still unsolved issues of rapidly on-going societal and technological changes. Rooting from the general climate change concerns, recently, sustainability transformation has become a special focus in the EU, which is facing new and very concrete demands—to elucidate the evidence-based pathways towards the green transformation with European Green Deal and European Climate Law targets ahead. The main aim of this research is to disclose the pathway towards the green transformation in Lithuania in one of the fast-growing research fields of circular bioeconomy—biogas production from manure and waste. To reach this aim, a hybrid methodology approach was used. Analysis and synthesis of scientific literature, document analysis and structuring, stakeholder mapping, inte... [more]
Application of Artificial Intelligence in the Unit Commitment System in the Application of Energy Sustainability
Bohumír Garlík
March 1, 2023 (v1)
Subject: Environment
Keywords: CO2 reduction, compact city, economic growth, energy consumption, Energy Efficiency, Modelling, Optimization, renewable energy sources, sustainable development, unit commitment
This article approaches the optimal solution of energy sustainability based on the use of artificial intelligence (AI). The application of renewable energy sources (RES) and unit commitment (UC) is the basic idea of this concept. Therefore, a new approach to solving the UC problem is introduced. The proposed method has a simple procedure to obtain the popular solutions in an acceptable time interval, by creating a basic model of the schedule of the state of energy units RES. It is obvious that individual consumer units, of an operational nature, take hourly performance values by performing economic evaluations on them in the sense of cost optimization. This is conducted through an artificial intelligence (AI) algorithm by optimizing the dedicated cost function, simulated by annealing. Despite the acceptable solution obtained from these two steps, another shift is proposed, called the TDD process in a given consumer area. This process in the application of AI in the system of selection... [more]
Simulations and Analysis of the Optimum Uniformity for Pedestrian Road Lighting Focusing on Energy Performance and Spill Light in the Roadside Environment
Constantinos A. Bouroussis, Annika K. Jägerbrand
March 1, 2023 (v1)
Subject: Environment
Keywords: analysis, artificial light, ecological impact, ecosystems, energy performance indicators, light pollution, lighting metrics, road lighting
Road lighting uniformity is an essential lighting quality parameter for motorists and pedestrians and varies with lighting design parameters. Increased road lighting uniformity may result in benefits, such as increased reassurance and perceived safety for pedestrians or an increased overall visual perception. However, no previous study has investigated how road lighting uniformity varies with lighting design scenarios or how the uniformity of various lighting design scenarios affects other essential parameters, such as energy performance and obtrusive light. This study aimed to investigate: (I) how uniformity varies with different road lighting design scenarios, and (II) how uniformity correlates with energy performance and risk for increasing spill light. The study is limited to pedestrian roads. We performed photometric calculations in ReluxDesktop for more than 1.5 million cases with single-sided pole arrangements and for various geometries of road width, pole distance, pole height,... [more]
Performance Study of Methane Dry Reforming on Ni/ZrO2 Catalyst
Anis H. Fakeeha, Abdulrahman Kurdi, Yousef A. Al-Baqmaa, Ahmed A. Ibrahim, Ahmed E. Abasaeed, Ahmed S. Al-Fatesh
March 1, 2023 (v1)
Subject: Environment
Keywords: dry reforming of CH4, greenhouse gases, nickel, synthesis gas, ZrO2
Dry reforming of methane (DRM) has important and positive environmental and industrial impacts, as it consumes two of the top greenhouse gases in order to produce syngas (H2 and CO) and thus hydrogen (H2). The performance of DRM of conversions of CH4 and CO2 was investigated over Ni/ZrO2 catalysts. The catalytic performance of all prepared catalysts for DRM was assessed in a micro-tubular fixed bed reactor under similar reaction conditions (i.e., activation and reaction temperatures at 700 °C, a feed flow rate of 70 mL/min, reaction temperature, and a 440 min reaction time). Various characterization techniques, such as BET, CO2-TPD, TGA, XRD, EDX, and TEM, were employed. The zirconia support was modified with MgO or Y2O3. The yttria-stabilized zirconia catalyst (5Ni15YZr) provided the optimum activity performance of CH4 and CO2 conversions of 56.1 and 64.3%, respectively, at 700 °C and a 70 mL/min flow rate; this catalyst also had the highest basicity. The Ni-based catalyst was promote... [more]
Comparing the Energy System of a Facility with Uncertainty about Future Internal Carbon Prices and Energy Carrier Costs Using Deterministic Optimisation and Two-Stage Stochastic Programming
Oliver Gregor Gorbach, Jessica Thomsen
March 1, 2023 (v1)
Subject: Environment
Keywords: decarbonisation, deterministic optimisation, energy system optimisation, internal carbon pricing, optimisation results’ robustness, proxy prices, two-stage stochastic programming
For an organisation, one aspect on the path to a decarbonised future is the cost-optimal decarbonisation of their facilities’ energy systems. One method to guide the decarbonisation is internal carbon pricing. However, the design process of decarbonisation pathways, guided by internal carbon prices, can be challenging, since the energy system environment consists of many uncertainties. Despite the numerous uncertainties and existing methods to address uncertainties during the optimisation process, the optimisation of a facility’s energy system is often done by assuming perfect knowledge of all relevant input parameters (deterministic optimisation). Since real-world decisions can never be based on perfect knowledge and certain decisions might lead to path dependencies, it is important to consider the robustness of a solution in the context of developments that vary from the assumed scenarios. So far, no academic work has analysed the potential benefits of using an optimisation method th... [more]
Iron Recovery Technology of Red Mud—A review
Hao Kong, Tuo Zhou, Xinhua Yang, Yingli Gong, Man Zhang, Hairui Yang
March 1, 2023 (v1)
Subject: Environment
Keywords: fluidized bed reduction, iron recovery, pyrometallurgical method, red mud
RM (red mud), which comes from the Bayer process, has a huge annual output and is harmful to the environment. Because of the high iron content in RM, the process of iron recovery from RM can reduce the amount of RM well and create economic benefits, so it is a promising process. The paper focuses on the review on the research of the iron recovery method from RM, which includes the physical recovery method, chemical recovery method and emerging recovery method. By comparing the advantages and disadvantages of these processes, it is concluded that the fluidized bed reduction is a promising process that can be rapidly applied to the industry, but it still needs more investigation to overcome the current technical difficulties in the near future.
Comparative Analysis of Overheating Risk for Typical Dwellings and Passivhaus in the UK
Jihoon Jang, Sukumar Natarajan, Joosang Lee, Seung-Bok Leigh
March 1, 2023 (v1)
Subject: Environment
Keywords: climate change, global warming, overheating risk, Passivhaus, thermal comfort
There is growing concern that airtight and well-insulated buildings designed to limit heat loss in temperate and cold climates could unintentionally elevate the risk of overheating in summers. Existing literature primarily uses dynamic simulation to investigate this problem due to the difficulty of obtaining large-scale in-performance data. To address this gap, we undertake a meta-analysis of large-scale indoor air temperature data for 195 UK dwellings, as a study of performance in a temperate climate. Of these, 113 are baseline (i.e., typical existing dwellings) and the rest designed to the high-performance Passivhaus standard. Using both Passivhaus and the well-known CIBSE TM59 overheating standards, this study found that there were few overheated cases for any building type. However, the average summer nighttime temperature of Passivhaus bedrooms was 1.6 °C higher than baseline, with 20 out of 31 measured bedrooms exceeding the overheating criterion, and the average overheating hour... [more]
Energy-Model and Life Cycle-Model for Grinding Processes of Limestone Products
Viktoria Mannheim, Weronika Kruszelnicka
March 1, 2023 (v1)
Subject: Environment
Keywords: Bond mill, energy-model, grinding, life cycle assessment, life cycle-model, limestone, particle size distribution, specific grinding work, stirred ball mill
Fine and ultrafine grinding of limestone are frequently used in the pharmaceutical, chemical, construction, food, and cosmetic industries, however, research investigations have not yet been published on the combination of energy and life cycle modeling. Therefore, the first aim of this research work was the examination of main grinding parameters of the limestone particles to determine an empiric energy-model. Dry and wet grinding experiments have been carried out with a Bond mill and a laboratory stirred ball mill. During the grinding processes, the grinding time and the filling ratio have been adjusted. The second goal of this research assessed the resources, emissions and environmental impacts of wet laboratory grinding with the help of life cycle assessment (LCA). The life cycle assessment was completed by applying the GaBi 8.0 (version: 10.5) software and the CML method. As a result of research, the determination of an empiric energy-model allowed to develop an estimated particle... [more]
Passive Small Direct Alcohol Fuel Cells for Low-Power Portable Applications: Assessment Based on Innovative Increments since 2018
Maria H. de Sá, Alexandra M. F. R. Pinto, Vânia B. Oliveira
March 1, 2023 (v1)
Subject: Environment
Keywords: low-power, microgenerators, passive small direct alcohol fuel cells (PS-DAFCs), portable applications, recent R&D innovations, review analysis, Sustainability
Passive small direct alcohol fuel cells (PS-DAFCs) are compact, standalone devices capable of electrochemically converting the chemical energy in the fuel/alcohol into electricity, with low pollutant emissions and high energy density. Thus, PS-DAFCs are extremely attractive as sustainable/green off-grid low-power sources (milliwatts to watts), considered as alternatives to batteries for small/portable electric and electronic devices. PS-DAFCs benefit from long life operation and low cost, assuring an efficient and stable supply of inherent non-polluting electricity. This review aims to assess innovations on PS-DAFC technology, as well as discuss the challenges and R&D needs covered on practical examples reported in the scientific literature, since 2018. Hence, this compilation intends to be a guidance tool to researchers, in order to help PS-DAFCs overcome the barriers to a broad market introduction and consequently become prime renewable energy converters and autonomous micropower gen... [more]
Green Growth, Economic Development, and Carbon Dioxide Emissions: An Evaluation Based on Cointegration and Vector Error Correction Models
Yu Sun, Mingxing Li, Hongzheng Sun, Shahida Kanwel, Mengjuan Zhang, Naila Erum, Abid Hussain
March 1, 2023 (v1)
Subject: Environment
Keywords: autoregressive integrated moving average (ARIMA) model, carbon dioxide emissions, economic development level, environmental Kuznets curve (EKC) model, vector error correction (VEC) model
Economic development is mainly dependent on fossil fuels. The massive use of fossil fuels has led to changes in the climate environment, in which the deterioration of air quality has affected people’s daily lives. This paper introduces the green growth level as a control variable to explore the connection between carbon dioxide emissions and the level of economic growth. It uses the EKC algorithm and VEC model to analyze Nanjing city’s data from 1993 to 2018. Given the data availability, the ARIMA algorithm was used to project carbon emissions for 2019−2025. It is found that the EKC curve of Nanjing City shows an N-shape, and the growth of economic level will cause the enhancement of carbon dioxide emissions. Carbon emissions will reach 7,592,140 tons in 2025. At present, we are in an essential stage of transition from N-shape to inverted U-shape, and this paper makes several recommendations based on the findings.
Depositional Paleo-Environments of Lower Cambrian Qiongzhusi Formation in the Western Middle Yangtze Block and Its Controlling Effect on the Organic Matter Enrichment
Zhengkai Lan, Junjun Shen
March 1, 2023 (v1)
Subject: Environment
Keywords: black shale, depositional paleoenvironment, enrichment model, main factors controlling of organic matter enrichment, organic matter, western Middle Yangtze Block
No systematic comparative study has been conducted on the factors controlling organic matter enrichment in the different depositional environments of the Lower Cambrian Qiongzhusi Formation in the western Middle Yangtze Block, leading to a large discrepancy in our understanding. Based on organic geochemical and elemental analyses of core, outcrop, rock, and mineral samples from the slope, deep-water shelf, and shallow-water shelf, in this study, comparative analysis of the organic matter content, sedimentological characteristics, and depositional paleoenvironments of the Lower Cambrian Qiongzhusi Formation in the western Middle Yangtze Block was conducted, and the main controlling factors and models of the organic matter enrichment were investigated. The results revealed that the organic matter enrichment in the Qiongzhusi Formation was jointly controlled by redox conditions, water restriction, upwelling currents, terrigenous inputs, and paleo-productivity, but the main factors control... [more]
Interrogating the Installation Gap and Potential of Solar Photovoltaic Systems Using GIS and Deep Learning
Sumit Kalyan, Qian (Chayn) Sun
March 1, 2023 (v1)
Subject: Environment
Keywords: Ballarat, deep learning, GIS, Renewable and Sustainable Energy, solar PV systems, sustainable development
Non-renewable-resource consumption and global greenhouse-gas (GHG) emissions are critical issues that pose a significant threat to sustainable development. Solar energy is a promising source to generate renewable energy and an appealing alternative electricity source for households. The primary goal of this research is to detect the rooftops that have no solar photovoltaic (PV) system deployed on them but that receive moderate to high solar-energy radiation using the Geographic Information System (GIS) and deep-learning techniques. Although various studies have been conducted on this subject, not many addressed these two issues simultaneously at a residential level. Identifying the installed solar PV systems in a large area can be expensive and time-consuming work if performed manually. Therefore, the deep-learning algorithm is an emerging alternative method to detect objects using aerial images. We employed the Single-Shot-Detector (SSD) model with the backbone of residual neural netw... [more]
Pilot Study on Removal Characteristics of Multiple Pollutants by the Dual Baghouse Filter System
Guopeng Luo, Kai Zhang, Yaqi Peng, Jinjin Wang, Shengyong Lu, Qunxing Huang, Jianhua Yan
February 28, 2023 (v1)
Subject: Environment
Keywords: dioxins, dual bag, HCl, heavy metals, pilot study, removal
A 1000 Nm3/h capacity pilot scale dual baghouse filter system was tested on flue gas and fly ash from a municipal solid waste incinerator, and the removal efficiency of dioxins, heavy metals and HCl was studied. Activated carbon was injected at the inlet of the first baghouse filter to remove the gas phase dioxins and heavy metals, and baking soda was injected at the inlet of the second baghouse filter to remove HCl. Concentrations of dioxins at the outlet of the first and second baghouse were 0.034 and 0.011 ng TEQ/Nm3, respectively, which were both far below the national emission standard. The particulate matter concentration was 0.85 mg/m3, and the heavy metals leaching concentration of the fly ash from the second baghouse filter was lower than the hazardous waste identification standard. HCl concentration was almost zero at the outlet of the second baghouse filter when the optimal equivalence ratio of baking soda to HCl was 1.6. In addition, the estimated fly ash yield was 2.35% of... [more]
Industrial End-Users’ Preferred Characteristics for Wood Biomass Feedstocks
Kalvis Kons, Boško Blagojević, Blas Mola-Yudego, Robert Prinz, Johanna Routa, Biljana Kulisic, Bruno Gagnon, Dan Bergström
February 28, 2023 (v1)
Subject: Environment
Keywords: bioenergy, biohubs, conjoint analysis, expert analysis, PAPRIKA method
The use of sustainably sourced biomass is an important tool for mitigating the effects of climate change; but biomass is far from being a homogeneous resource. The aim of this study was to examine the decision-making process of industrial end-users considering biomass procurement. An online, two-part survey generated responses from 27 experienced professionals, representing a portfolio of facilities varying in size, technology, and biomass types, across Australia, Canada, Finland, and Sweden. A PAPRIKA conjoint analysis approach was used to analyze the data so that the attributes that influenced procurement decisions could be weighted and ranked. The results provided an insight into end-users’ views on factors including facility location, size, and biomass storage, handling, and procurement for different wood-based industrial services. The most important decision-making attribute appeared to be the type of biomass assortment, at individual, national, and aggregated levels. Of seven sub... [more]
Impedance Characteristics and Harmonic Analysis of LCL-Type Grid-Connected Converter Cluster
Xiaojie Zhou, Dezhi Xu, Yourui Huang
February 28, 2023 (v1)
Subject: Environment
Keywords: converter cluster, harmonic analysis, LCL-type grid-connected converter, output impedance
This study addresses the output impedance model of the LCL-type grid-connected converter considering the dead-time effects and the digital control delay. The model shows that the digital control delay will affect the accuracy of the output impedance of the grid-connected converter, and the dead-time effects are only equivalent to superimposing a disturbance voltage on the original output impedance model. The derived output impedance model is verified by comparing it with the switching model in the PSIM simulation environment. The harmonic interaction between converter cluster and utility grid is modeled and analyzed based on the output impedance model. A combined harmonic suppression strategy is incorporated into every converter control scheme to suppress the harmonic interaction. Simulation results are presented to demonstrate the correctness of harmonic interaction analysis and the effectiveness of the proposed suppression strategy.
Study on the Discharge Characteristics along the Surface and Charge Movement Characteristics of Insulating Media in an Airflow Environment
Guangquan Zhang, Xueqin Zhang, Bo Wang, Yujun Guo, Guoqiang Gao, Guangning Wu
February 28, 2023 (v1)
Subject: Environment
Keywords: airflow environment, conduction mechanism, discharge along the surface, electric charge motion, insulation media, trap level
The gas−solid interface of high-voltage insulating equipment is a weaker part of insulating equipment insulation, and preventing the occurrence of discharge along the surface of insulating equipment is a critical problem for high-voltage insulation. This article investigates the discharge characteristics and charge movement characteristics of insulating media under an airflow environment. The surface discharge characteristics of the insulating medium in the airflow environment were obtained by using a high-velocity airflow test platform, and the surface discharge voltage characteristics, discharge path characteristics, and force conditions of the discharge process were analyzed. The surface charge motion characteristics of the insulating medium in the high-velocity airflow environment were also tested, and the distribution characteristics, dissipation characteristics and conduction mechanism of the surface charge of the insulating medium in the high-velocity airflow environment were re... [more]
Correlation between the Production of Electricity by Offshore Wind Farms and the Demand for Electricity in Polish Conditions
Arkadiusz Dobrzycki, Jacek Roman
February 28, 2023 (v1)
Subject: Environment
Keywords: correlation between solar and wind power plants, offshore wind power, power demand, RES
Energy transition forcing a change in the structure of the electricity generation system is a particularly difficult task in countries such as Poland, where the dominant source of energy is fossil fuels. Due to the nature of renewable sources (stochastic and seasonally variable), it is necessary to study their impact on the power system. Much research was conducted on this subject. They consider modelling power systems in terms of dealing with an increasing amount of renewable energy sources, stabilization of electricity generation or environmental aspects. This article examines one of the key sources of future power systems—offshore wind turbines (OWT). The influence of offshore wind sources on the power system in the fields of stability of generation, methods of regulatory strategies, and economics were examined. One of the aspects that are less considered is the correlation of energy production in OWT with energy demand and with generation in other renewable energy sources, especial... [more]
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