Hasil untuk "Production of electric energy or power. Powerplants. Central stations"

Haojing Tian, Beibei Wang, Jie L et al.

Suresh Tejavath, Varsha A Shah, Akanksha Shukla

P. Sangeetha, G. Suresh Babu, E. Vidyasagar

Renewable energy sources play an important role in the future of electrical energy generation due to the reduction in existing fossil fuels. Solar energy and wind energy are renowned and easily accessible renewable energy sources. Connecting these sources to distribution system impacts reliability due to the unpredictable nature of the atmosphere. This paper presents a reliability assessment of distribution systems with renewable distributed energy resources (DER) units like wind turbine generators (WTG), electric storage systems (ESS), photovoltaic (PV) panels, and electric vehicle charging stations (EVCS). The stochastic characteristics of the DER sources and EVCS are analyzed by using the Markov model and the impact of the integration of DER sources into the distribution system is evaluated. The effects of DER and EVCS on the distribution system’s overall reliability and economy are assessed by using indices like System Average Interruption Frequency Index (SAIFI) and System Average Interruption Duration Index (SAIDI). Various scenarios are considered to evaluate the benefits of integrating WTG, ESS, PV, and EVCS into the distribution system in terms of reliability and stability. The results presented illustrate that the addition of DERs and EVCS into the distribution system improves its reliability and enhances resiliency.

Abu Shufian, Sowrov Komar Shib, Durjoy Roy Dipto et al.

Enhancing power quality (PQ) in electrical distribution systems is vital for maintaining a stable and reliable power supply, especially for sensitive industrial and commercial loads prone to voltage disturbances. With the increasing integration of renewable energy sources (RES) and the widespread adoption of advanced electronic devices, modern power grids face growing challenges in addressing voltage sags, swells, and harmonics, threatening equipment performance and system reliability. This study proposes a comprehensive solution by implementing a Three-phase Dynamic Voltage Restorer (DVR) integrated with a Fuzzy Logic Controller (FLC). The selection of FLC stems from its ability to mimic human decision-making and handle non-linear, imprecise data, offering superior adaptability and precision compared to traditional control methods. Unlike conventional algorithms, which struggle under fluctuating grid conditions and complex disturbances, FLC dynamically adjusts the output of DVR based on real-time reference and load voltage measurements. This ensures optimal compensation and consistent voltage regulation across varying operating scenarios. The DVR, strategically placed downstream of a transformer within a three-phase supply network, detects voltage disturbances and compensates for deviations in real time. The developed optimization model demonstrates the effectiveness of proposed system, achieving an impressive 95% efficiency in correcting voltage disturbances and significantly reducing total harmonic distortion (THD) to 2.41%. Furthermore, the system showcases exceptional performance in handling voltage sags, reducing them to as low as 0.68% and an ultra-fast response time of less than 0.5 ms, surpassing the capabilities of conventional methods. The FLC-based DVR system offers robust voltage regulation, improved fault resilience, and enhanced grid stability by addressing critical PQ challenges exacerbated by the transition to RES and increased dependency on sensitive loads. Its advanced features make it a transformative solution for mitigating voltage disturbances in grid-connected systems, ensuring reliability and efficiency in the face of modern energy demands.

Claudia Roberta Calidonna, Arijit Dutta, Francesco D’Amico et al.

Accurate near-surface wind speed and direction measurements are crucial for validating atmospheric models, especially for the purpose of adequately assessing the interactions between the surface and wind, which in turn results in characteristic vertical profiles. Coastal regions pose unique challenges due to the discontinuity between land and sea and the complex interplay of atmospheric stability, topography, and boundary/layer dynamics. This study focuses on a unique database of wind profiles collected over several years at a World Meteorological Organization—Global Atmosphere Watch (WMO/GAW) coastal site in the southern Italian region of Calabria (Lamezia Terme, code: LMT). By leveraging remote sensing technologies, including wind lidar combined with in situ measurements, this work comprehensively analyzes wind circulation at low altitudes in the narrowest point of the entire Italian peninsula. Seasonal, daily, and hourly wind profiles at multiple heights are analyzed, highlighting the patterns and variations induced by land–sea interactions. A case study integrating Synthetic Aperture Radar (SAR) satellite images and in situ observations demonstrates the importance of multi-sensor approaches in capturing wind dynamics and validating model simulations. Data analyses demonstrate the occurrence of extreme events during the winter and spring seasons, linked to synoptic flows; fall seasons have variable patterns, while during the summer, low-speed winds and breeze regimes tend to prevail. The prevailing circulation is of a westerly nature, in accordance with other studies on large-scale flows.

Marc Simon Henderson, Chau Chun Beh, Elsayed A. Oraby et al.

Over the next 5–10 years, the feedstock to lithium-ion battery recycling facilities will shift from Co- and Ni-rich chemistries to lower-value battery chemistries, such as lithium iron phosphate (LFP). Traditional recycling processes use toxic and corrosive inorganic acids for leaching, generating toxic waste streams. The low-value feedstocks will be LFP-rich with contamination from lithium cobalt oxide (LCO) and lithium–nickel–manganese–cobalt oxide (NMC) battery chemistries. Overall, the lower-value feedstock coupled with the need to reduce environmentally damaging waste streams requires the development of robust, green leaching processes capable of selectively targeting the LFP and LCO/NMC battery chemistries. This research concluded that a first-stage oxalic acid leach could selectively extract Al, Li, and P from the industrially sourced LFP-rich black mass. When operating at the optimal conditions (0.5 M oxalic acid, 5% solids, pH 0.8, and an agitation speed of 600 rpm), >99% of the Li and P and >97% of the Al were selectively extracted after 2 h, while Mn, Fe, Cu, Ni, and Co extractions were kept relatively low, namely, at 19%, <3%, <1%, 0%, and 0%. This research also explored a second-stage leach to treat the first-stage leach residue using ascorbic acid, citric acid, and glycine. It was concluded that when leaching with glycine (30 g/L glycine, a temperature of 40 °C, an agitation speed of 600 rpm, and 2% solids at pH 9.6), that >97% of the Co, >77% of the Ni, and 41% of the Mn were extracted, while the co-extraction percentages of Cu, Fe, and Al were <27%, <4%, and <2%.

Jiexiang Wu, Li Li, Jiangfeng Zhang et al.

Electric vehicles offer environmental benefits but pose challenges to power grids during peak demand. This study introduces a method to optimize electric vehicle charging and incorporate vehicle-to-grid technology, aiming to minimize electricity costs and electric vehicle loads during peak periods. Two models are developed to evaluate electric vehicle owners’ willingness to participate in both non-vehicle-to-grid and vehicle-to-grid scenarios, providing insights into future peak demand increases and potential reductions through optimization.A case study in Texas, USA, utilizing data from the Pecan Street database, reveals that by 2030, the increase in peak electric vehicle charging demand could exceed the current levels by over 4.7 times. This surge is up to 3.16% of the total electricity demand in Texas. However, with the implementation of the proposed optimization methods, electric vehicles could potentially feed about 747 MWh of energy back into the grid, effectively transforming them from energy consumers to suppliers during high-demand periods. This demonstrates the crucial role that electric vehicles, coupled with strategic charging and vehicle-to-grid technologies, can play in not only mitigating emissions but also in enhancing grid stability and efficiency.

Lei Wang, Chenyu Yang, Zhilong Xu et al.

Due to the increasing problems of global warming and the gradual depletion of non-renewable energy sources, how to achieve low-carbon energy transition has become the focus of the entire energy industry. The article combines the policies related to carbon emission quotas and certified emission reductions in China, and designs a carbon credit trading mechanism that takes into account the synergy between electricity trading and carbon trading, based on which a carbon and electricity coupling market model is established with a carbon credit trading center as the core. Firstly, the carbon credit trading rules are prospectively formulated for the new power system, which connects power suppliers and power load users to form a diversified organic whole; secondly, the carbon credit management center is built with blockchain technology, which aims to shape the power spot market, power futures market and carbon trading market into a composite coupling, forming a new carbon and power coupled market with the carbon credit management center as the core, and the business interconnection and synergistic clearing of each market. Finally, a new carbon market model with carbon credit mechanism is established, and the components of nodal electricity prices are explored to quantify the impact of introducing carbon credit constraints on nodal marginal electricity prices. The results of the algorithm analyze the economic efficiency and social welfare of the electricity suppliers and load users, illustrate the necessity of introducing the carbon credit trading mechanism, and analyze the impact of the high proportion of renewable energy access on the carbon electricity coupling market.

Jiafang Huang, Zhengguang Song, Junxiong Wu et al.

Rechargeable room-temperature (RT) sodium–sulfur (Na–S) batteries hold great potential for large-scale energy storage owing to their high energy density and low cost. However, their practical application is hindered by challenges such as polysulfide shuttling and Na dendrite formation. In this study, a dual salt-based quasi-solid polymer electrolyte (DS–QSPE) was developed via in situ polymerization, achieving high ionic conductivity (4.8 × 10−4 S·cm−1 at 25 °C), a high sodium-ion transference number (0.73), and effective polysulfide confinement. Theoretical calculations and experimental results indicate that the enhanced Na-ion transport is attributed to the strengthened coordination of anions with the polydioxolane chain and the increased dissociation of sodium salts. Importantly, the DS–QSPE forms an interconnected network structure in the sulfurized polyacrylonitrile (SPAN) cathode. This provides abundant and seamless electrochemical reaction interfaces that facilitate efficient and uniform ion transport pathways. As a result, the Na||SPAN battery with DS–QSPE delivers a high capacity of approximately 327.4 mAh·g−1 (based on the mass of SPAN) after 200 cycles at 0.2 A·g−1, retaining 81.4% of its initial capacity. This performance considerably surpasses that of batteries using liquid electrolytes. This study offers a straightforward approach to addressing the interfacial challenges in solid-state Na–S batteries.

Taorong Jia, Lixiao Yao, Guoqing Yang

Abstract Given the complex form of distribution line faults, the accuracy of fault location using traditional artificial intelligence networks needs to be further improved. Here, a combined fault location method is proposed for a 110 kV distribution line based on the improved complete ensemble empirical mode decomposition with adaptive noise (ICEEMDAN), mantis search algorithm (MSA), and convolutional gate recurrent unit (ConvGRU). Firstly, the study used the ICEEMDAN algorithm to decompose the signals and discard the high‐frequency signals with low correlation so as to achieve the purpose of noise cancellation. Then, the study used the root mean square error (RMSE) of the ConvGRU model training as the adaptation value, optimized the internal parameters of the model using the MSA algorithm, and obtained a combined fault locating model. By using the proposed model, the effects of the fault form and transition impedance changes on the location accuracy were analysed, and the location accuracy was compared with other artificial intelligence methods. The location accuracy index showed that the proposed model had a better convergence speed of training error than the traditional model. Also, the RMSE of the localization results was reduced by 50%, with a higher fault location accuracy.

Xiangqi Zhu, Partha Mishra, Barry Mather et al.

Rudranarayan Pradhan, Mohd Azeem, Premalata Jena

Ivo Malakov, Velizar Zaharinov, Stiliyan Nikolov et al.

In the present article, the solution for choosing the optimal structural variant of an industrial robot for extracting castings from die casting machines is considered. For this purpose, the process of extracting the castings from the mold is analyzed. On this basis, functions are defined, and a functional structure of the robot is built. Alternative variants of devices for each function are developed. The set of possible structural variants are constructed, considering the compatibility between devices and the possibility of performing more than one function with one device. The problem of choosing an optimal structural variant is formulated, and its characteristic features are determined. The main stages of a methodology and application software for the problem’s solution are presented. After an analysis of requirements for the extractor, the set of criteria for evaluating the structural variants are determined. The set includes criteria that minimize the production costs, production floor space, as well as the energy costs in the operation process, which is of particular importance in the conditions of global energy crisis. A mathematical model of the problem is built. The formulated multi-criteria optimization problem is solved, both with equal objective functions and with different priority.

Yoshiaki Abe, Taku Nonomura, Makoto Sato et al.

This study numerically investigated the mechanisms of separation control using a synthetic jet (SJ) and plasma actuator (PA) around an NACA0015 airfoil at the chord Reynolds number of 63,000. Both SJ and PA were installed on the leading edge with the same order of input momentum (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>C</mi><mi>μ</mi></msub><mrow><mo>=</mo><mi>O</mi><mo>(</mo></mrow><msup><mn>10</mn><mrow><mo>−</mo><mn>3</mn></mrow></msup></mrow></semantics></math></inline-formula>–<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mn>10</mn><mrow><mo>−</mo><mn>5</mn></mrow></msup><mrow><mo>)</mo></mrow></mrow></semantics></math></inline-formula>) and the same actuation frequencies in <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi>F</mi><mo>+</mo></msup><mo>=</mo><mn>1.0</mn></mrow></semantics></math></inline-formula>–30. The momentum coefficient <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>C</mi><mi>μ</mi></msub></semantics></math></inline-formula> is defined as the normalized momentum introduced from the SJ or the PA, and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>F</mi><mo>+</mo></msup></semantics></math></inline-formula> stands for the actuation frequency normalized by the chord length and uniform velocity. A number of large-eddy simulations (LES) were conducted for the SJ and the PA, and the mechanisms were clarified in terms of the exchange of chordwise momentum with Reynolds shear stress and coherent vortex structures. First, four main differences in the induced flows of the SJ and the PA were clarified as follows: (A) wall-tangential velocity; (B) three-dimensional flow structures; (C) spatial locality; and (D) temporal fluctuation. Then, a common feature of flow control by the SJ and the PA was revealed: a lift-to-drag ratio was found to be better recovered in <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi>F</mi><mo>+</mo></msup><mo>=</mo><mn>6.0</mn></mrow></semantics></math></inline-formula>–20 than in other frequencies. Although there were differences in the induced flows, the phase decomposition of the flow fields identified common mechanisms that the turbulent component of the Reynolds shear stress mainly contributes to the exchange of the chordwise (streamwise) momentum; and the turbulent vortices are convected over the airfoil surface by the coherent spanwise vortices in the frequency of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>F</mi><mo>+</mo></msup></semantics></math></inline-formula>.

Xiao Tang, Zhi Zhang, Xueliang Liu et al.

In this study, a novel field-oriented control (FOC) algorithm was proposed in a 60° coordinate system for controlling the speed of permanent magnet synchronous motors. The FOC algorithm consists of several parts in which the reference currents and feedback currents are transformed into the representation form in a 60° coordinate system. Current regulators are typically used in a 60° coordinate system to directly obtain the reference voltage vector. The proposed FOC structure was established by incorporating the space vector pulse width modulation algorithm in a 60° coordinate system. The proposed FOC structure simplified the FOC algorithm and reduced its computational burden. The feasibility of the proposed method was verified through simulations and experiments.

Moushumi Patowary, Hassan Haes Alhelou, Gayadhar Panda

Abstract A relative assessment on conventional and adaptive current controllers used in reduced sensor‐maximum power point tracking (MPPT) based photovoltaic (PV)‐grid tied inverter systems for the improvement of system power quality is suggested. The steady‐state and transients errors produced in the conventional PI and proportional resonant controllers, which are used to generate the references, can be fixed by using an intelligent ADALINE‐LMS adaptive controller; moreover, it helps in reducing the %THD (total harmonic distortion) level measured at different power zones. Also, to track the maximum PV power, which is further integrated to DC‐bus, a reduced sensor‐based technology is added into the circuit that sidesteps the problem of tracking local MPP instead of global MPP and the drawbacks of using current sensors. The use of a reduced sensor‐based MPPT controller confirms extraction of maximum PV power and it guarantees a constant DC‐link voltage under all the possible test conditions. The overall control architectures and system performances, which are tested under different system dynamics, are validated through MATLAB/Simulink as well as experimental findings obtained using the dSPACE RTI 1202 interfacing kit. These experimental results confirm that the adaptive control technique used in reduced sensor‐MPPT based PV‐grid tied inverter systems performs unbeatably with balanced load and grid voltages, less harmonics, quick response time etc. under the operation of linear, non‐linear and transient loads, whereas, conventional controllers are best only for the linear loads.

Yandi Gallego Landera, Lesyani Leon Viltre, Grettel Quintana de Basterra et al.

La energía solar sigue siendo una de las mejores opciones disponibles entre las fuentes renovables de energía, ya que es abundante, limpia y confiable. Debido a la susceptibilidad del sistema fotovoltaico frente a fallas en la red, convencionalmente, el inversor fotovoltaico se desconectaría de la misma. Sin embargo, muchos países han implementado códigos de red para asegurar y regular la operación de los sistemas fotovoltaicos durante fallas en la red. Las tecnologías modernas han equipado a los inversores fotovoltaicos, entre otras cosas, con la capacidad de conducción de bajo voltaje (LVRT). En este documento se analizan los controladores de corriente para la inyección de corriente bajo condiciones de LVRT. Estos controladores se han clasificado en dos categorías principales: controladores lineales y los controles no lineales de corriente. Además, se ha presentado un análisis comparativo, discutiendo las ventajas y desventajas de estos esquemas de control.

Reza Hemmati, Hossien Faraji

Abstract This paper presents a control mechanism on high voltage direct current (HVDC) transmission line for frequency/voltage regulation, fault ride through (FRT) capability, and cyber‐attack/fault detection. The network under study consists of two areas with different frequencies that are connected through one 300 km HVDC line. The proposed control system regulates the frequency in both areas by managing power through HVDC line. The converters on both sides of HVDC line are controlled to handle faults on the DC and AC sections as well as improving fault ride through capability. The control strategies are implemented and operated depending on fault/cyber‐attack type and behaviour. In this respect, the control mechanism may change the firing angle of converters, switch their operating mode from rectifier to converter and vice‐versa or even block the converters. The proposed paradigm successfully distinguishes between the cyber‐attacks and faults. The simulations in MATLAB software validate that the proposed mechanism realizes all the objectives and the cyber‐attacks are completely identified and separated from the faults.

Josnier Ramos Guardarrama, Maykop Pérez Martínez, Raimundo Carlos Silverio Freire et al.

En este trabajo se analiza el comportamiento del modelo en el espacio de estados del convertidor reductor bajo la condición de frontera entre el modo de conducción continuo y discontinuo. El modelo matemático que representa el convertidor, está desarrollado específicamente para el modo de conducción continua, y apoyándonos en este, es caracterizado su comportamiento dinámico cuando se acerca al punto umbral entre los modos de conducción. De esta forma es posible comprender los efectos que produce la proximidad al punto umbral sobre la respuesta del convertidor, cómo se comporta la respuesta transitoria y estable, lo que permite conocer si el comportamiento del modelo es parcial o totalmente utilizable. Como novedad, se determinas las condiciones limitantes del modelo con respecto a la operación cercana del punto umbral, entre conducción continua o discontinua y qué tipo de respuesta es la correcta en la simulación.

Chen Fang, Xiaojin Zhao, Qin Xu et al.