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Energies, Volume 10, Issue 7 (July 2017)

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Cover Story (view full-size image) Alternative fuels are an important aspect of transportation and energy production. The study of [...] Read more.
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Open AccessEditorial Energy and Waste Management
Energies 2017, 10(7), 1072; https://doi.org/10.3390/en10071072
Received: 22 June 2017 / Revised: 19 July 2017 / Accepted: 19 July 2017 / Published: 24 July 2017
Cited by 2 | PDF Full-text (199 KB) | HTML Full-text | XML Full-text
Abstract
Waste management and energy systems are often interlinked, either directly by waste-to-energy technologies, or indirectly as processes for recovery of resources—such as materials, oils, manure, or sludge—use energy in their processes or substitute conventional production of the commodities for which the recycling processes
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Waste management and energy systems are often interlinked, either directly by waste-to-energy technologies, or indirectly as processes for recovery of resources—such as materials, oils, manure, or sludge—use energy in their processes or substitute conventional production of the commodities for which the recycling processes provide raw materials. A special issue in Energies on the topic of “Energy and Waste Management” attained a lot of attention from the scientific community. In particular, papers contributing to improved understanding of the combined management of waste and energy were invited. In all, 9 papers were published out of 24 unique submissions. The papers cover technical topics such as leaching of heavy metals, pyrolysis, and production of synthetic natural gas in addition to different systems assessments of horse manure, incineration, and complex future scenarios at a national level. All papers except one focused on energy recovery from waste. That particular paper focused on waste management of infrastructure in an energy system (wind turbines). Published papers illustrate research in the field of energy and waste management on both a current detailed process level as well as on a future system level. Knowledge gained on both types is necessary to be able to make progress towards a circular economy. Full article
(This article belongs to the Special Issue Energy and Waste Management)
Open AccessArticle Research on Capacitance Current Compensation Scheme of Current Differential Protection of Complex Four-Circuit Transmission Lines on the Same Tower
Energies 2017, 10(7), 1071; https://doi.org/10.3390/en10071071
Received: 19 June 2017 / Revised: 10 July 2017 / Accepted: 19 July 2017 / Published: 23 July 2017
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Abstract
Current differential protection is the main protection of transmission lines which include multi-circuit lines on the same tower, and whose sensitivity and reliability of differential protection is mainly affected by the distributed capacitive current. For the four-circuit line on the same tower, due
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Current differential protection is the main protection of transmission lines which include multi-circuit lines on the same tower, and whose sensitivity and reliability of differential protection is mainly affected by the distributed capacitive current. For the four-circuit line on the same tower, due to the influence of coupling between the loop road, the distributed capacitance current increases significantly when compared with ordinary lines, affecting the sensitivity of the current differential protection, especially for different voltage levels throughout the four-circuit lines on the same tower. The relationship of the electrostatic coupling between the circuits is more complex, and increases the difficulty of the compensating the distributed capacitance current. This paper is based on the electrostatic coupling principle of four-circuit lines on the same tower, establishes the distributed parameter model of four-circuit transmission lines on the same tower, and discusses the effect of circuit operation mode on the compensation of capacitance current differential protection when different faults occur on the complex four-circuit transmission lines on the same tower. A new compensation scheme suitable for capacitive current compensation is proposed. Simulation results show that this capacitive current compensation scheme can effectively improve the performance of current differential protection. Full article
(This article belongs to the Section Electrical Power and Energy System)
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Open AccessArticle Influence of the Steam Addition on Premixed Methane Air Combustion at Atmospheric Pressure
Energies 2017, 10(7), 1070; https://doi.org/10.3390/en10071070
Received: 10 June 2017 / Revised: 7 July 2017 / Accepted: 20 July 2017 / Published: 23 July 2017
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Abstract
Steam-diluted combustion in gas turbine systems is an effective approach to control pollutant emissions and improve the gas turbine efficiency. The primary purpose of the present research is to analyze the influence of steam dilution on the combustion stability, flame structures, and CO
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Steam-diluted combustion in gas turbine systems is an effective approach to control pollutant emissions and improve the gas turbine efficiency. The primary purpose of the present research is to analyze the influence of steam dilution on the combustion stability, flame structures, and CO emissions of a swirl-stabilized gas turbine model combustor under atmospheric pressure conditions. The premixed methane/air/steam flame was investigated with three preheating temperatures (384 K/434 K/484 K) and the equivalence ratio was varied from stoichiometric conditions to the flammability limits where the flame was physically blown out from the combustor. In order to represent the steam dilution intensity, the steam fraction Ω defined as the steam to air mass flow rate ratio was used in this work. Exhaust gases were sampled with a water-cooled emission probe which was mounted at the combustor exit. A 120 mm length quartz liner was used which enabled the flame visualization and optical measurement. Time-averaged CH chemiluminescence imaging was conducted to characterize the flame location and it was further analyzed with the inverse Abel transform method. Chemical kinetics calculation was conducted to support and analyze the experimental results. It was found that the LBO (lean blowout) limits were increased with steam fraction. CH chemiluminescence imaging showed that with a high steam fraction, the flame length was elongated, but the flame structure was not altered. CO emissions were mapped as a function of the steam fraction, inlet air temperature, and equivalence ratios. Stable combustion with low CO emission can be achieved with an appropriate steam fraction operation range. Full article
(This article belongs to the Section Energy Fundamentals and Conversion)
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Open AccessArticle A Novel Workflow for Geothermal Prospectively Mapping Weights-of-Evidence in Liaoning Province, Northeast China
Energies 2017, 10(7), 1069; https://doi.org/10.3390/en10071069
Received: 3 July 2017 / Revised: 18 July 2017 / Accepted: 19 July 2017 / Published: 22 July 2017
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Abstract
Geological faults are highly developed in the eastern Liaoning Province in China, where Mesozoic granitic intrusions and Archean and Paleoproterozoic metamorphic rocks are widely distributed. Although the heat flow value in eastern Liaoning Province is generally low, the hot springs are very developed.
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Geological faults are highly developed in the eastern Liaoning Province in China, where Mesozoic granitic intrusions and Archean and Paleoproterozoic metamorphic rocks are widely distributed. Although the heat flow value in eastern Liaoning Province is generally low, the hot springs are very developed. It is obvious that the faults have significant control over the distribution of hot springs, and traditional methods of spatial data analysis such as WofE (weight of evidence) usually do not take into account the direction of the distribution of geothermal resources in the geothermal forecast process, which seriously affects the accuracy of the prediction results. To overcome the deficiency of the traditional evidence weight method, wherein it does not take the direction of evidence factor into account, this study put forward a combination of the Fry and WofE methods, Fry-WofE, based on geological observation, gravity, remote sensing, and DEM (digital elevation model) multivariate data. This study takes eastern Liaoning Province in China as an example, and the geothermal prospect was predicted respectively by the Fry-WofE and WofE methods from the statistical data on the spatial distribution of the exposed space of geothermal anomalies the surface. The result shows that the Fry-WofE method can achieve better prediction results when comparing the accuracy of these two methods. Based on the results of Fry-WofE prediction and water system extraction, 13 favorable geothermal prospect areas are delineated in eastern Liaoning Province. The Fry-WofE method is effective in study areas where the geothermal distribution area is obviously controlled by the fault. We provide not only a new method for solving the similar issue of geothermal exploration, but also a new insight into the distribution of geothermal resources in Liaoning Province. Full article
(This article belongs to the Section Energy Sources)
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Open AccessArticle Modeling Noise Sources and Propagation in External Gear Pumps
Energies 2017, 10(7), 1068; https://doi.org/10.3390/en10071068
Received: 21 June 2017 / Revised: 8 July 2017 / Accepted: 20 July 2017 / Published: 22 July 2017
Cited by 1 | PDF Full-text (10671 KB) | HTML Full-text | XML Full-text
Abstract
As a key component in power transfer, positive displacement machines often represent the major source of noise in hydraulic systems. Thus, investigation into the sources of noise and discovering strategies to reduce noise is a key part of improving the performance of current
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As a key component in power transfer, positive displacement machines often represent the major source of noise in hydraulic systems. Thus, investigation into the sources of noise and discovering strategies to reduce noise is a key part of improving the performance of current hydraulic systems, as well as applying fluid power systems to a wider range of applications. The present work aims at developing modeling techniques on the topic of noise generation caused by external gear pumps for high pressure applications, which can be useful and effective in investigating the interaction between noise sources and radiated noise and establishing the design guide for a quiet pump. In particular, this study classifies the internal noise sources into four types of effective load functions and, in the proposed model, these load functions are applied to the corresponding areas of the pump case in a realistic way. Vibration and sound radiation can then be predicted using a combined finite element and boundary element vibro-acoustic model. The radiated sound power and sound pressure for the different operating conditions are presented as the main outcomes of the acoustic model. The noise prediction was validated through comparison with the experimentally measured sound power levels. Full article
(This article belongs to the Special Issue Energy Efficiency and Controllability of Fluid Power Systems)
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Open AccessArticle Control Strategy for a Grid-Connected Inverter under Unbalanced Network Conditions—A Disturbance Observer-Based Decoupled Current Approach
Energies 2017, 10(7), 1067; https://doi.org/10.3390/en10071067
Received: 17 June 2017 / Revised: 3 July 2017 / Accepted: 10 July 2017 / Published: 22 July 2017
Cited by 6 | PDF Full-text (8653 KB) | HTML Full-text | XML Full-text
Abstract
This paper proposes a new approach on the novel current control strategy for grid-tied voltage-source inverters (VSIs) with circumstances of asymmetrical voltage conditions. A standard grid-connected inverter (GCI) allows the degree of freedom to integrate the renewable energy system to enhance the penetration
[...] Read more.
This paper proposes a new approach on the novel current control strategy for grid-tied voltage-source inverters (VSIs) with circumstances of asymmetrical voltage conditions. A standard grid-connected inverter (GCI) allows the degree of freedom to integrate the renewable energy system to enhance the penetration of total utility power. However, restrictive grid codes require that renewable sources connected to the grid must support stability of the grid under grid faults. Conventional synchronously rotating frame dq current controllers are insufficient under grid faults due to the low bandwidth of proportional-integral (PI) controllers. Hence, this work proposes a proportional current controller with a first-order low-pass filter disturbance observer (DOb). The proposed controller establishes independent control on positive, as well as negative, sequence current components under asymmetrical grid voltage conditions. The approach is independent of parametric component values, as it estimates nonlinear feed-forward terms with the low-pass filter DOb. A numerical simulation model of the overall power system was implemented in a MATLAB/Simulink (2014B, MathWorks, Natick, MA, USA). Further, particular results show that double-frequency active power oscillations are suppressed by injecting appropriate negative-sequence currents. Moreover, a set of simulation results provided in the article matches the developed theoretical background for its feasibility. Full article
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Open AccessArticle Thermal and Performance Analysis of a Gasification Boiler and Its Energy Efficiency Optimization
Energies 2017, 10(7), 1066; https://doi.org/10.3390/en10071066
Received: 14 June 2017 / Revised: 14 July 2017 / Accepted: 20 July 2017 / Published: 22 July 2017
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Abstract
The purpose of this study was to determine a method for multi-parametric output regulation of a gasification boiler especially designed for heating or for hot water heating in buildings. A new method of regulation is offered, namely more parametric regulation via proportional-integral-derivative (PID)
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The purpose of this study was to determine a method for multi-parametric output regulation of a gasification boiler especially designed for heating or for hot water heating in buildings. A new method of regulation is offered, namely more parametric regulation via proportional-integral-derivative (PID) controllers that are capable of controlling the calculated values of pressure, temperature and fan speed. These values of pressure, temperature and fan speed are calculated in a completely new way, and calculations of setpoints for determination of optimal parameters lead to an increase in boilers efficiency and power output. Results of measurements show that changes at the mouth of the stack draft due atmospheric influences occur in times with high intensity and high frequency, while power parameters, or boiler power output amplitudes and fan speed automatically “copy” those changes proportionally due to instantaneous fan speed changes. The proposed method of regulation of the gasification boiler power output according to the technical solution enables a simple, cheap, express and continuous maintenance of high power output at low concentrations of the exhaust gases of the gasification boilers from the viewpoint of the boiler user, as well as from the perspective of development and production it allows a continuous control monitoring of these parameters. Full article
(This article belongs to the Section Energy Sources)
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Open AccessArticle Effects of Anisotropic Thermal Conductivity and Lorentz Force on the Flow and Heat Transfer of a Ferro-Nanofluid in a Magnetic Field
Energies 2017, 10(7), 1065; https://doi.org/10.3390/en10071065
Received: 8 June 2017 / Revised: 5 July 2017 / Accepted: 18 July 2017 / Published: 22 July 2017
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Abstract
In this paper, we study the effects of the Lorentz force and the induced anisotropic thermal conductivity due to a magnetic field on the flow and the heat transfer of a ferro-nanofluid. The ferro-nanofluid is modeled as a single-phase fluid, where the viscosity
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In this paper, we study the effects of the Lorentz force and the induced anisotropic thermal conductivity due to a magnetic field on the flow and the heat transfer of a ferro-nanofluid. The ferro-nanofluid is modeled as a single-phase fluid, where the viscosity depends on the concentration of nanoparticles; the thermal conductivity shows anisotropy due to the presence of the nanoparticles and the external magnetic field. The anisotropic thermal conductivity tensor, which depends on the angle of the applied magnetic field, is suggested considering the principle of material frame indifference according to Continuum Mechanics. We study two benchmark problems: the heat conduction between two concentric cylinders as well as the unsteady flow and heat transfer in a rectangular channel with three heated inner cylinders. The governing equations are made dimensionless, and the flow and the heat transfer characteristics of the ferro-nanofluid with different angles of the magnetic field, Hartmann number, Reynolds number and nanoparticles concentration are investigated systematically. The results indicate that the temperature field is strongly influenced by the anisotropic behavior of the nanofluids. In addition, the magnetic field may enhance or deteriorate the heat transfer performance (i.e., the time-spatially averaged Nusselt number) in the rectangular channel depending on the situations. Full article
(This article belongs to the Section Energy Fundamentals and Conversion)
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Open AccessArticle Utilizing Non-Equilibrium Thermodynamics and Reactive Transport to Model CH4 Production from the Nankai Trough Gas Hydrate Reservoir
Energies 2017, 10(7), 1064; https://doi.org/10.3390/en10071064
Received: 15 April 2017 / Revised: 9 July 2017 / Accepted: 18 July 2017 / Published: 22 July 2017
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Abstract
The ongoing search for new sources of energy has brought natural gas hydrate (NGH) reservoirs to the forefront of attention in both academia and the industry. The amount of gas reserves trapped within these reservoirs surpasses all of the conventional fossil fuel sources
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The ongoing search for new sources of energy has brought natural gas hydrate (NGH) reservoirs to the forefront of attention in both academia and the industry. The amount of gas reserves trapped within these reservoirs surpasses all of the conventional fossil fuel sources explored so far, which makes it of utmost importance to predict their production potential and safety. One of the challenges facing those attempting to analyse their behaviour is that the large number of involved phases make NGHs unable to ever reach equilibrium in nature. Field-scale experiments are expensive and time consuming. However, computer simulations have now become capable of modelling different gas production scenarios, as well as production optimization analyses. In addition to temperature and pressure, independent thermodynamic parameters for hydrate stabilization include the hydrate composition and concentrations for all co-existing phases. It is therefore necessary to develop and implement realistic kinetic models accounting for all significant routes for dissociation and reformation. The reactive transport simulator makes it easy to deploy nonequilibrium thermodynamics for the study of CH4 production from hydrate-bearing sediments by considering each hydrate-related transition as a separate pseudo reaction. In this work, we have used the expanded version of the RetrasoCodeBright (RCB) reactive transport simulator to model exploitation of the methane hydrate (MH) reservoir located in the Nankai Trough, Japan. Our results showed that higher permeabilities in the horizontal direction dominated the pressure drop propagation throughout the hydrate layers and affected their hydrate dissociation rates. Additionally, the comparison of the vertical well versus the horizontal well pattern indicated that hydrate dissociation was slightly higher in the vertical well scenario compared to the horizontal. Full article
(This article belongs to the Special Issue Methane Hydrate Research and Development)
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Open AccessArticle Adaptive Model Predictive Control-Based Energy Management for Semi-Active Hybrid Energy Storage Systems on Electric Vehicles
Energies 2017, 10(7), 1063; https://doi.org/10.3390/en10071063
Received: 30 May 2017 / Revised: 1 July 2017 / Accepted: 18 July 2017 / Published: 22 July 2017
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Abstract
This paper deals with the energy management strategy (EMS) for an on-board semi-active hybrid energy storage system (HESS) composed of a Li-ion battery (LiB) and ultracapacitor (UC). Considering both the nonlinearity of the semi-active structure and driving condition uncertainty, while ensuring HESS operation
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This paper deals with the energy management strategy (EMS) for an on-board semi-active hybrid energy storage system (HESS) composed of a Li-ion battery (LiB) and ultracapacitor (UC). Considering both the nonlinearity of the semi-active structure and driving condition uncertainty, while ensuring HESS operation within constraints, an adaptive model predictive control (AMPC) method is adopted to design the EMS. Within AMPC, LiB Ah-throughput is minimized online to extend its life. The proposed AMPC determines the optimal control action by solving a quadratic programming (QP) problem at each control interval, in which the QP solver receives control-oriented model matrices and current states for calculation. The control-oriented model is constructed by linearizing HESS online to approximate the original nonlinear model. Besides, a time-varying Kalman filter (TVKF) is introduced as the estimator to improve the state estimation accuracy. At the same time, sampling time, prediction horizon and scaling factors of AMPC are determined through simulation. Compared with standard MPC, TVKF reduces the estimation error by 1~3 orders of magnitude, and AMPC reduces LiB Ah-throughput by 4.3% under Urban Dynamometer Driving Schedule (UDDS) driving cycle condition, indicating superior model adaptivity. Furthermore, LiB Ah-throughput of AMPC under various classical driving cycles differs from that of dynamic programming by an average of 6.5% and reduces by an average of 10.6% compared to rule-based strategy of LiB Ah-throughput, showing excellent adaptation to driving condition uncertainty. Full article
(This article belongs to the Section Energy Storage and Application)
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Open AccessArticle An Optimization Framework for Investment Evaluation of Complex Renewable Energy Systems
Energies 2017, 10(7), 1062; https://doi.org/10.3390/en10071062
Received: 31 May 2017 / Revised: 10 July 2017 / Accepted: 11 July 2017 / Published: 22 July 2017
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Abstract
Enhancing the role of renewable energies in existing power systems is one of the most crucial challenges that society faces today. However, the high variability of their generation potential and the temporal disparity between the demand and the generation potential represent technological and
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Enhancing the role of renewable energies in existing power systems is one of the most crucial challenges that society faces today. However, the high variability of their generation potential and the temporal disparity between the demand and the generation potential represent technological and operational gaps that burden the massive incorporation of renewable sources into power systems. Energy storage technologies are an alternative to tackle this gap; nonetheless, their incorporation within large-scale power grids calls for decision-making tools that ensure an appropriate design and sizing of power systems that exploit the benefits of incorporating storage facilities along with renewable generation power. In this paper, we present an optimization framework for aiding the evaluation of the strategic design of complex renewable power systems. The developed tool relies on an optimization problem, the generation, transmission, storage energy location and sizing problem, which allows one to compute economically-attractive investment plans given by the location and sizing of generation and storage energy systems, along with the corresponding layout of transmission lines. Results on a real case study (located in the central region of Chile), characterized by carefully-curated data, show the potential of the developed tool for aiding long-term investment planning. Full article
(This article belongs to the Special Issue Energy Production Systems)
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Open AccessArticle Biomass Production from Crops Residues: Ranking of Agro-Energy Regions
Energies 2017, 10(7), 1061; https://doi.org/10.3390/en10071061
Received: 4 July 2017 / Revised: 19 July 2017 / Accepted: 20 July 2017 / Published: 22 July 2017
Cited by 2 | PDF Full-text (607 KB) | HTML Full-text | XML Full-text
Abstract
The aim of the paper is to rank the agro-energy regions according to their potentials of biomass production in the Region of Central Macedonia (RCM). For this reason, a model of Multi-Criteria Analysis (MCDA) is developed with the ELimination and Et Choix Traduisant
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The aim of the paper is to rank the agro-energy regions according to their potentials of biomass production in the Region of Central Macedonia (RCM). For this reason, a model of Multi-Criteria Analysis (MCDA) is developed with the ELimination and Et Choix Traduisant la REalite (ELECTRE) ΙΙΙ method, with the construction of outranking relations. The aim is to compare in a comprehensive way each pair of action, in our case the agro-energy regions of the RCM, in order to satisfy the main goal which is to rank the seven regions as regards their biomass production. The final goal is to select the optimal crop plan as a pilot case for biomass production in the region. In the case of ELECTRE III multicriteria model, we used several conflicting criteria such as the farm income, the biomass production from crop residues, the variable costs, and the production of thermal energy and electrical energy. Alongside a technical and economic analysis of the study area is conducted for the existent crop plans of each agro-energy region. The results show that agro-energy regions with cereals and arable crops have better results than regions with fruit trees and other crops. Full article
(This article belongs to the Special Issue Biomass Chars: Elaboration, Characterization and Applications Ⅱ)
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Open AccessArticle Linking the Power and Transport Sectors—Part 1: The Principle of Sector Coupling
Energies 2017, 10(7), 956; https://doi.org/10.3390/en10070956
Received: 29 March 2017 / Revised: 4 July 2017 / Accepted: 6 July 2017 / Published: 21 July 2017
Cited by 12 | PDF Full-text (4422 KB) | HTML Full-text | XML Full-text
Abstract
The usage of renewable energy sources (RESs) to achieve greenhouse gas (GHG) emission reduction goals requires a holistic transformation across all sectors. Due to the fluctuating nature of RESs, it is necessary to install more wind and photovoltaics (PVs) generation in terms of
[...] Read more.
The usage of renewable energy sources (RESs) to achieve greenhouse gas (GHG) emission reduction goals requires a holistic transformation across all sectors. Due to the fluctuating nature of RESs, it is necessary to install more wind and photovoltaics (PVs) generation in terms of nominal power than would otherwise be required in order to ensure that the power demand can always be met. In a near fully RES-based energy system, there will be times when there is an inadequate conventional load to meet the overcapacity of RESs, which will lead to demand regularly being exceeded and thereby a surplus. One approach to making productive use of this surplus, which would lead to a holistic transformation of all sectors, is “sector coupling” (SC). This paper describes the general principles behind this concept and develops a working definition intended to be of utility to the international scientific community. Furthermore, a literature review provides an overview of relevant scientific papers on the topic. Due to the challenge of distinguishing between papers with or without SC, the approach adopted here takes the German context as a case study that can be applied to future reviews with an international focus. Finally, to evaluate the potential of SC, an analysis of the linking of the power and transport sectors on a worldwide, EU and German level has been conducted and is outlined here. Full article
(This article belongs to the Section Electrical Power and Energy System)
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Open AccessArticle Comparison of the Performance of Artificial Neural Networks and Fuzzy Logic for Recognizing Different Partial Discharge Sources
Energies 2017, 10(7), 1060; https://doi.org/10.3390/en10071060
Received: 16 May 2017 / Revised: 13 July 2017 / Accepted: 15 July 2017 / Published: 21 July 2017
Cited by 4 | PDF Full-text (5569 KB) | HTML Full-text | XML Full-text
Abstract
This paper compared the capabilities of the artificial neural network (ANN) and the fuzzy logic (FL) approaches for recognizing and discriminating partial discharge (PD) fault classes. The training and testing parameters for the ANN and FL comprise statistical fingerprints from different phase-amplitude-number (
[...] Read more.
This paper compared the capabilities of the artificial neural network (ANN) and the fuzzy logic (FL) approaches for recognizing and discriminating partial discharge (PD) fault classes. The training and testing parameters for the ANN and FL comprise statistical fingerprints from different phase-amplitude-number (φ-q-n) measurements. Two PD fault classes considered are internal discharges in voids and surface discharges. In the void class, there are single voids, serial voids and parallel voids in polyethylene terephthalate (PET), while the surface discharge class comprises four different surface discharge arrangements on pressboard in oil at different voltages and angular positioning of the ground electrode on the respective pressboards. Previously, the ANN and FL have been investigated for PD classification, but there is no work reported in the literature that compares their performance, specifically when applied for real time PD detection problem. As expected, both the ANN and FL can recognize PD defect classes, but the results show that the ANN appears to be more robust as compared to the FL, but these conclusions required to be further investigated with complex PD examples. Finally, both the ANN and FL were assessed as practical PD classification. Despite of the limitations of the ANN, it is concluded that the ANN is better suited for practical PD recognition because of its ability to provide accurate recognition values and the severity level of PD defects. Full article
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Open AccessArticle Pole-to-Ground Fault Analysis and Fast Protection Scheme for HVDC Based on Overhead Transmission Lines
Energies 2017, 10(7), 1059; https://doi.org/10.3390/en10071059
Received: 21 April 2017 / Revised: 18 June 2017 / Accepted: 16 July 2017 / Published: 21 July 2017
Cited by 4 | PDF Full-text (5486 KB) | HTML Full-text | XML Full-text
Abstract
Flexible direct current (DC) transmission network technology is an effective method for large capacity clean energy access to power grids, but the DC short-circuit fault detection for it is a difficult problem. In this paper, the pole-to-ground fault transient characteristics in a multi-terminal
[...] Read more.
Flexible direct current (DC) transmission network technology is an effective method for large capacity clean energy access to power grids, but the DC short-circuit fault detection for it is a difficult problem. In this paper, the pole-to-ground fault transient characteristics in a multi-terminal DC power grid, based on overhead transmission lines and DC circuit breakers, are analyzed firstly. Then, a fast protection scheme is proposed according to the fault transient characteristics. Only local information is utilized for fault detection and location in the proposed scheme. Moreover, the scheme is verified to have the advantages of fast action speed, high reliability and the ability to resist the transition resistance. A four terminal DC power grid model based on actual engineering parameters is established in PSCAD/EMTDC, and the validity of the protection scheme under different fault conditions is verified by simulation results. Full article
(This article belongs to the Section Electrical Power and Energy System)
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