The deployment of advanced nuclear technologies is anticipated to be part of the actions required to mitigate global climate change. The successful deployment of these new technologies, like all new infrastructure projects, will be more successful if the projects have strong public support. Successful deployment of energy infrastructure correlates with thoughtful approaches to equitable energy transitions. This work recalls the history of recent energy infrastructure deployments, shows where the inclusion of social scientists has improved the possibility of success and proposes specific steps to make future deployments of advanced nuclear technologies successful.

For several years, the increase of extreme meteorological events due to climate change, especially in unusual areas, has focused authorities and stakeholders attention on electric power systems’ resilience. In this context, the authors have developed a simulation model for managing the resilience of electricity distribution grids with respect to the main threats to which these infrastructures may be exposed (i.e., ice sleeves, heat waves, water bombs, floods, tree falls). The simulator identifies the more vulnerable network assets by means of probabilistic indexes, thus suggesting the best corrective actions to be implemented for resilience improvement. The fulfillment of grid constraints, i.e., loading limits for branches and voltage limits for buses, under actual operating conditions, is taken into account. Load scenarios extracted from available measurements are evaluated by means of load flow analyses in order to choose, among the best solutions identified, those compatible with th... [more]

As the applications of power electronic converters increase across multiple domains, so do the associated challenges. With multilevel inverters (MLIs) being one of the key technologies used in renewable systems and electrification, their reliability and fault ride-through capabilities are highly desirable. While using a large number of semiconductor components that are the leading cause of failures in power electronics systems, fault tolerance against switch open-circuit faults is necessary, especially in remote applications with substantial maintenance penalties or safety-critical operation. In this paper, a fault-tolerant asymmetric reduced device count multilevel inverter topology producing an 11-level output under healthy conditions and capable of operating after open-circuit fault in any switch is presented. Nearest-level control (NLC) based Pulse width modulation is implemented and is updated post-fault to continue operation at an acceptable power quality. Reliability analysis of... [more]

Low-income sub-Saharan Africa (SSA) households rely on wood for cooking for the simple reason that it is the lowest cost cooking fuel. Thus, full attainment of Sustainable Development Goal 7 (SDG7) requires developing clean cooking technologies that are cheaper than wood cooking. This study provides a comparative marginal levelized cost of energy (MLCOE) analysis for wood cooking vs. innovative solar electric cooking technologies. The two key off-grid solar technologies evaluated are: (1) direct-use DC solar (DDS) electricity for cooking applications, and (2) high-cycle-life lithium titanate (LTO) batteries. MLCOE is reported in USD/kWh for energy delivered to cooked food. A low median MLCOE of USD 0.125/kWh is attained using DDS electricity which is output directly by a solar panel with little or no intervening electricity storage and few electricity conversion and control costs. DDS solar panel output has variable voltage and current that is managed by a specialized DDS cooker. LTO b... [more]

This paper investigates the potential of a new integrated solar concentrated photovoltaic (CPV) system that uses a solo point focus Fresnel lens for multiple multi-junction solar cells (MJSCs). The proposed system comprises of an FL concentrator as the primary optical element, a multi-leg homogeniser as the secondary optical element (SOE), a plano-concave lens, and four MJSCs. A three-dimensional model of this system was developed using the ray tracing method to predict the influence of aperture width, height, and position with respect to MJSCs of different reflective and refractive SOE on the overall optical efficiency of the system and the irradiance uniformity achieved on the MJSCs’ surfaces. The results show that the refractive homogeniser using N-BK7 glass can achieve higher optical efficiency (79%) compared to the reflective homogeniser (57.5%). In addition, the peak to average ratio of illumination at MJSCs for the reflective homogeniser ranges from 1.07 to 1.14, while for the r... [more]

The development of the COVID-19 pandemic and the related lockdown had a major impact on vehicle traffic in cities. Based on available data from the selected city of Rzeszow, Poland, it was decided to assess changes in vehicle traffic and the impact of these changes on roadside environmental pollution. As part of the research, data from the first half of 2020 regarding vehicle traffic on selected streets of the city and on the city’s inlet routes were analyzed. For the selected road sections, changes in hourly traffic volume in 2020, compared with 2019, were also determined. With data on traffic volume, an attempt was made to estimate the impact of changes in traffic volume on air pollution in the city. Research on air pollution from motor vehicles was focused on a selected section of a city road that was equipped with an automatic air pollution measurement station located very close to the road. Additionally, at the road intersection and in the vicinity of the measuring station, a sens... [more]

(1) Background: The growing demand for developing new methods of degraded land remediation is linked to the need to improve the soil environment, including post-industrial soils. Biological methods such as the aided phytostabilisation technique are the most common methods applied to achieve effective remediation. This study aimed to determine the technical potential of methods using novel or yet not used soil amendments, such as blast furnace slag (BFS) and coal slag (CS), with Dactylis glomerata L. as a test plant. (2) Methods: The experiment was conducted on post-industrial area soil with high concentrations of Cu (761 mg/kg), Cd (23.9 mg/kg), Pb (13,539 mg/kg) and Zn (8683 mg/kg). The heavy metal content in roots and the above-ground parts of plants and soil was determined by flame atomic absorption spectrometry. (3) Results: The addition of BFS to the soil was the most effective in increasing Dactylis glomerata L. biomass yield. The Cu, Cd, Pb, and Zn concentrations were higher in... [more]

Microwave torrefaction of oat hull was conducted to enhance its physicochemical properties. A bench-top reactor with an internal stirrer was used for oat hull pretreatment at temperatures of 225 °C, 255 °C, and 285 °C, and residence times of 3, 6, and 9 min, respectively. Results showed that a high temperature level at 3 min residence time or severe torrefaction increased calorific values by up to 35% of its original value, while decreasing mass yield down to 60.77%. Severe torrefaction further decreased moisture absorption, moisture content, and grinding energy consumption but decreased energy yield and bulk density. Residence time had no significant effect on biomass physicochemical changes; however, production cost may be significantly increased by longer residence times. It was also concluded that increased microwave power levels from 400 to 650 W decreased energy consumption by shortening processing times, resulting in a positive economic impact of the process. Moderate and severe... [more]

The Brushless Doubly-Fed Reluctance Generator (BDFRG) is a potential alternative to the Doubly Fed Induction Generator (DFIG) in wind power applications owing to its reasonable cost, competitive performance, and high reliability. In comparison with the Brushless Doubly-Fed Induction Generator (BDFIG), the BDFRG is more efficient and easier to control owing to the cage-less rotor. One of the most preferable advantages of BDFRG over DFIG is the inherently better performance under unbalanced grid conditions. The study conducted in this paper showed that conventional vector control of the BDFRG results in excessive oscillations of the primary active/reactive power, electromagnetic torque, and primary/secondary currents in this case. In order to address such limitations, this paper presented a new control strategy for the unbalanced operation of BDFRG-based wind generation systems. A modified vector control scheme was proposed with the capability to control the positive and the negative seq... [more]

Hard coal is widely used as a source of energy, and a number of catalysts have been developed to minimize the noxious impact of this fuel on combustion. This paper presents the cost-efficiency analysis of a system for improving the combustion of solid fuels, especially fine coal, in power boilers. The system is provided with a control and supervision device. It has been designed for better accuracy in controlling the boiler operating parameters, with a view to improving combustion efficiency due to the use of catalysts. The tests were carried out for system capacities ranging from 3 to 100 MW. It was found that, depending on the size of the system in the range of 3−100 MW, savings in the fuel consumption ranged from 2% to 8% due to the implementation of novel solutions in the boiler plant operation and from 2 to 6% due to the use of the combustion catalysts. Apart from boosting energy efficiency, the use of catalysts and the efficiency-boosting system resulted in the costs of overhauls... [more]

Research on the modeling and fault diagnosis of rotor eccentricities has been conducted during the past two decades. A variety of diagnostic theories and methods have been proposed based on different mechanisms, and there are reviews following either one type of electric machines or one type of eccentricity. Nonetheless, the research routes of modeling and diagnosis are common, regardless of machine or eccentricity types. This article tends to review all the possible modeling and diagnostic approaches for all common types of electric machines with eccentricities and provide suggestions on future research roadmap. The paper indicates that a reliable low-cost non-intrusive real-time online visualized diagnostic method is the trend. Observer-based diagnostic strategies are thought promising for the continued research.

This work aims to study the drying of clay ceramic materials with arbitrary shapes theoretically. Advanced phenomenological mathematical models based on lumped analysis and their exact solutions are presented to predict the heat and mass transfers in the porous material and estimate the transport coefficients. Application has been made in hollow ceramic bricks. Different simulations were carried out to evaluate the effect of drying air conditions (relative humidity and speed) under conditions of forced and natural convection. The transient results of the moisture content and temperature of the brick, and the convective heat and mass transfer coefficients are presented, discussed and compared with experimental data, obtaining a good agreement. It was found that the lower the relative humidity is and the higher the speed of the drying air is, the higher the convective heat and mass transfer coefficients are at the surface of the brick and in the holes, and the faster the moisture removal... [more]

The article describes an assessment of possible changes in constant fatigue life of a medium flow-coefficient centrifugal compressor impeller subject to operation at close-to-surge point. Some aspects of duct acoustics are additionally analyzed. The experimental measurements at partial load are presented and are primarily used for validation of unidirectionally coupled fluid-structural numerical model. The model is based on unsteady finite-volume fluid-flow simulations and on finite-element transient structural analysis. The validation is followed by the model implementation to replicate the industry-scale loads with reasonably higher rotational speed and suction pressure. The approach demonstrates satisfactory accuracy in prediction of stage performance and unsteady flow field in vaneless diffuser. The latter is deduced from signal analysis relying on continuous wavelet transformations. On the other hand, it is found that the aerodynamic incidence losses at close-to-surge point are un... [more]

District of Namaacha in Maputo Province of Mozambique presents a high wind potential, with an average wind speed of around 7.5 m/s and huge open fields that are favourable to the installation of wind farms. However, in order to make better use of the wind potential, it is necessary to evaluate the operating conditions of the turbines and guide the independent power producers (IPPs) on how to efficiently use wind power. The investigation of the wind farm operating conditions is justified by the fact that the implementation of wind power systems is quite expensive, and therefore, it is imperative to find alternatives to reduce power losses and improve energy production. Taking into account the power needs in Mozambique, this project applied hybrid optimisation of multiple energy resources (HOMER) to size the capacity of the wind farm and the number of turbines that guarantee an adequate supply of power. Moreover, considering the topographic conditions of the site and the operational para... [more]

Renewable energy sources such as wind power and photovoltaics (PVs) have been increasingly integrated into the power system through power electronic converters in recent years. However, power electronic converter-driven stability has issues under specific circumstances, for instance, modal resonances might deteriorate the dynamic performance of the power systems or even threaten the overall stability. In this work, the integration impact of a hybrid renewable energy source (HRES) system on modal interaction and converter-driven stability was investigated in an IEEE 16-machine 68-bus power system. In this paper, firstly, an HRES system is introduced, which consists of full converter-based wind power generation (FCWG) and full converter-based photovoltaic generation (FCPV). The equivalent dynamic models of FCWG and FCPV are then established, followed by linearized state-space modeling. On this basis, converter-driven stability analysis was performed to reveal the modal resonance mechanis... [more]

The performance of a conventional Class-E2-based WPT system is sensitive to system parameters such as the coil coupling coefficient and load variation. System efficiency decreases rapidly when the coil coupling coefficient and load deviate from their optimum values. In this paper, an impedance matching method and a design procedure are proposed to maintain high system efficiency over a wider range of coupling coefficient and load variations. The load-pull technique is adopted to identify the high-efficiency load region of a Class-E power amplifier (PA), and a double-L-type impedance matching network (IMN) is proposed to transform the load impedance of a Class-E PA into a high-efficiency working region. Compared to a single L-type IMN, a double-L-type IMN is more flexible and has better tuning performance. A 6.78 MHz Class-E2-based WPT system was built to validate the proposed design method. The experimental results show that the proposed double-L-type IMN can significantly attenuate th... [more]

In recent years, cities are expected to develop in line with the smart city (S.C.) idea. Cities, perceived as attractive places for people to live, must now meet many conditions. A city’s duty is, among others, to meet the needs and expectations of both, its residents and newcomers, offering a wide range of opportunities for entrepreneurs, caring for the natural environment, constantly taking on new challenges, and meeting them for its further development. Thus, the management of a city involves undertaking activities in line with the smart city idea. However, to implement them, they use widely available means, defined as intelligent solutions, e.g., modern ICT technologies. In line with the smart city idea, a city is a center inhabited by people who create a civic and participatory society, having the ability to use the latest ICT solutions and having access to a range of services and solutions offered by the city. Since the smart city idea is considered at many levels, it is still un... [more]

The heat transfer Magnetohydrodynamics flows have been potentially used to enhance the thermal characteristics of several systems such as heat exchangers, electromagnetic casting, adjusting blood flow, X-rays, magnetic drug treatment, cooling of nuclear reactors, and magnetic devices for cell separation. Our concern in this article is to numerically investigate the flow of an incompressible Magnetohydrodynamics micropolar fluid with heat transportation through a channel having porous walls. By employing the suitable dimensionless coordinates, the flow model equations are converted into a nonlinear system of dimensionless ordinary differential equations, which are then numerically treated for different preeminent parameters with the help of quasi-linearization. The system of complex nonlinear differential equations can efficiently be solved using this technique. Impact of the problem parameters for microrotation, temperature, and velocity are interpreted and discussed through tables and... [more]

Multi-station integration is motivated by the requirements of distributed energies interconnection and improvements in the efficiency of energy systems. Due to the diversity of communication services and the complexity of data exchanges between in-of-station and out-of-station, multi-station integrated systems have high security requirements. However, issues related to cyber security for multi-station integrated systems are seldom explored. Hence, this paper designs the secondary system architecture and proposes cyber security protection solutions for smart energy stations (SESt) that integrate the substation, photovoltaic station, energy storage station, electric vehicle charging station, and data center station. Firstly, the composition of SESt and functions of each substation are presented, a layered architecture of SESt is designed, and data exchanges of SESt are analyzed. Then, the cyber security threats and requirements of SESt are illustrated. Moreover, the cyber security protec... [more]

It is effective to open the bus-coupler circuit breaker in case of a short-circuit fault. A fast vacuum circuit breaker (FVCB) is an ideal bus-coupler circuit breaker due to its high velocity. The objective of this study was to develop and test a 252 kV/2500 A-40 kA multi-break bus-coupler FVCB. The 252 kV FVCB contained 12 FVCB units. Each phase consisted of four FVCB units connected in series. Each FVCB unit had an electromagnetic repulsion mechanism with an average opening velocity reaching 6.5 m/s. Test results showed the opening time was 1.11 ± 0.08 ms. The capacitance of the voltage grading capacitor of each break was determined to be 10 nF. The prototype 252 kV bus-coupler FVCB passed all partial test duties according to the IEC 62271-100: 2008 and IEC 62271-1: 2007 standards, which include an insulation test and a terminal fault test among others. A 252 kV/2500 A-40 kA multi-break bus-coupler FVCB can be used to quickly cut off a short-circuit fault and effectively limit a shor... [more]

Due to increased grid problems caused by renewable energy systems being used to realize zero energy buildings and communities, the importance of energy sharing and self-sufficiency of renewable energy also increased. In this study, the energy performance of an energy-sharing community was investigated to improve its energy efficiency and renewable energy self-sufficiency. For a case study, a smart village was selected via detailed simulation. In this study, the thermal energy for cooling, heating, and domestic hot water was produced by ground source heat pumps, which were integrated with thermal energy storage (TES) with solar energy systems. We observed that the ST system integrated with TES showed higher self-sufficiency with grid interaction than the PV and PVT systems. This was due to the heat pump system being connected to thermal energy storage, which was operated as an energy storage system. Consequently, we also found that the ST system had a lower operating energy, CO2 emissio... [more]

The article summarizes research on essential contributors to energy dissipation in an actuator for an exemplary planetary exploration hopping robot. It was demonstrated that contact dynamics could vary significantly depending on the surface type. As a result, regolith is a significant uncertainty factor to the control loop and plays a significant contribution in the control system development of future planetary exploration robots. The actual prototype of the actuating mechanism was tested on a reference surface and then compared with various surfaces (i.e., Syar, quartz sand, expanded clay, and quartz aggregate) to estimate the dissipation of the energy in the initial phase of hopping. Test outcomes are compared with multibody analysis. The research enhances trajectory planning and adaptive control of future hopping robots by determining three significant types of energy losses in the system and, most importantly, determining energy dissipation coefficients in contact with the various... [more]

Distribution networks were conceived to distribute the energy received from transmission and subtransmission to supply passive loads. This approach, however, is not valid anymore due to the presence of distributed generation, which is mainly based on renewable energies, and the increased number of plug-in electric vehicles that are connected at this voltage level for domestic use. In this paper the ongoing transition that distribution networks face is addressed. Whereas distributed renewable energy sources increase nodal voltages, electric vehicles result in demand surges higher than the load predictions considered when planning these networks, leading to congestion in distribution lines and transformers. Additionally, centralized control techniques are analyzed to reduce the impact of distributed generation and electric vehicles and increase their effective integration. A classification of the different methodologies applied to the problems of voltage control and congestion management... [more]

In recent studies, various reports reveal that stubble burning of crop residues in India generates nearly 150 million tons of carbon dioxide (CO2), more than 9 million tons of carbon monoxide (CO), a quarter-million tons of sulphur oxides (SOX), 1 million tons of particulate matter and more than half a million tons of black carbon. These contribute directly to environmental pollution, as well as the haze in the Indian capital, New Delhi, and the diminishing glaciers of the Himalayas. Although stubble burning crop residue is a crime under Section 188 of the Indian Penal Code (IPC) and the Air and Pollution Control Act (APCA) of 1981, a lack of implementation of these government acts has been witnessed across the country. Instead of burning, crop residues can be utilized in various alternative ways, including use as cattle feed, compost with manure, rural roofing, bioenergy, beverage production, packaging materials, wood, paper, and bioethanol, etc. This review article aims to present th... [more]

This article reports the results of a study into the effect of operating parameters on the occurrence and course of gas−liquid two-phase phenomena during the fogging process carried out with the use of a conical pressure-swirl nozzle. Four alternatives of the stub regulation angles and four values of pressure of air supply to the nozzle were tested as part of the current research. The range of the investigated variables was common for the operation of fumigators used to prevent the spread of SARS-CoV-2 virus. The liquid flow rate (weighting method), the field of velocity, and turbulent flow intensity factor, as well as velocity profiles over the section of 1 m from the nozzle were determined using the particle image velocimetry (PIV) technique. The obtained results were correlated with the measurements of the diameters of spray droplets using the laser light scattering (LLS) technique. On the basis of this research, a dependence between the nozzle parameters and the spray cone pattern... [more]