bluuebunny/crossref_metadata_2025 huggingface dataset:
Modification of Control System Based on Virtual Synchronous Generator with Feedforward Control for Power Converters of Distributed Generation
Authors: Askarov Alisher , Ufa Ruslan , Suvorov Aleksey , Kievets Anton
Published: November 2024

An important development trend for modern power systems is the application of control algorithms for power converters based on a virtual synchronous generator (VSG), which can mimic the characteristics of the conventional synchronous generation and support the grid-forming operation. This paper proposes a modified current-controlled VSG structure (CC-VSG) with a feedforward controller consisting of a simple proportional loop, which is added to the VSG active power control loop, to improve the damping properties of CC-VSG, reduce the model order of this control system and simplify the approach to its tuning. In order to qualitatively and quantitatively analyse the effectiveness of the proposed solution, the paper presents a comparison of dynamic responses when using control algorithms based on CC-VSG or the traditional VSG structures, including several of their modifications. For this purpose, time-domain simulation of the considered system was performed, demonstrating the absence of impact of the feedforward control on the inertial response of CC-VSG, which can occur when using other VSG structures or local negative feedbacks within the CC-VSG itself.
On Reliability of 110-500 kV GIS: Operational Experience
Authors: Korotchenko Evgeniy , Galiaskarov Irek , Misrikhanov Misrikhan , Ryabchenko Vladimir , Shuntov Andrey
Published: November 2024

The accident rate of gas-insulated switchgears (GIS) is considered. The statistical sample covered 30 110-500 kV switchgear switchgears in a vast region of the European part of the country for the period 2008-2022. Their design features and technical characteristics are given. Significant and insignificant failures of GIS, including their structure, namely, distribution by elements of installations, technical and organizational causes of occurrence, dependence on the year of operation are subjected to analysis. The flow parameter (frequency) of GIS failures is determined, as well as the maximum possible time of GIS restoration after damage to the arc suppression chamber of the pole of the 500 kV circuit breaker. Comparative data are given with failure rate of GIS abroad and with gas-insulated circuit breaker cells in open switchgears.
Issues of risk-oriented approach to electrical networks reliability management
Authors: Vanin Artem , Gabdushev Dmitry , Tulsky Vladimir
Published: November 2024

The features of implementing a risk-oriented approach in Russian regulatory documents are examined. A brief overview of foreign experience is provided. The need for and a method of incorporating fault statistics in the calculation of failure probability based on asset health indexes are demonstrated. Additionally, the necessity of considering the duration of power supply interruptions in assessing the consequences of equipment failure is shown, along with a proposed method for doing so.
Methodology for Analysis of System Reliability When Planning States and Balances of Electric Power Systems
Authors: Krupenev Dmitry
Published: November 2024

The article presents the main provisions of the methodology for analyzing the system reliability of electric power systems when planning their states and balances. The type of system reliability for solving problems when planning the states and balances of electric power systems is called planned reliability. A substantive statement of the problem of assessing planned reliability is formulated, where the main requirements for taking into account the factors influencing the determined indicators are noted. In the general structure of the methodology, based on the sequential Monte Carlo method, three main stages are distinguished: the stage of forming pseudo-random processes of functioning of electric power systems, the stage of analyzing the states of functioning of electric power systems, the stage of calculating the indicators of planned reliability.
Model for Minimizing Energy Consumption of Electric Power Systems Taking Into Account the Balance of Active and Reactive Power
Authors: Iakubovskii Dmitrii , Krupenev Dmitry , Boyarkin Denis
Published: November 2024

The work covers the developed model of minimization of active power shortage taking into account the balance of active and reactive power. The motivation for the formation and testing of this model is the need to improve the adequacy of models of this class, as well as the need to implement it in the developed methodology for assessing planned reliability. The article specifies the requirements for the model and the process of its formation, which is based on the models of minimization of active power shortage and the optimal power flow format models. When forming the model, the required set of parameters was specified, namely, the modules of busbar voltages, phase angles of voltages, active and reactive resistance, and balance constraints of active and reactive power were formed. As a result of the analysis of experiments using circuits with 3 nodes, a difference in the result of the minimum power shortage (from 3.05 to 4.46%) was revealed compared to the problem based on the model of minimization of active power shortage without taking into account reactive power in balance constraints.
Methods for Calculating the Resistance of Grounding Devices with Backfilling Special Compositions
Authors: Drako Mikhail , Pavlovich Ivan , Baraishuk Siarhei
Published: November 2024

Traditional analytical methods for calculating and designing of grounding devices (GDs) in heterogeneous soils can lead to results that do not correspond to those obtained in practice. The empirical coefficients used in calculations of grounding systems given in various literature sources do not always give an explicable and significant discrepancy with the same initial data. In this paper, some well-known methods for calculating the spreading resistance of GDs are considered and the obtained results are compared with experimental data. It is shown that the recommendations and algorithms for calculating the resistance of GDs, presented in the well-known reference literature and regulatory documentation, do not give full and correct description for grounding devices installed in heterogeneous soil. In particular, it is shown that such a factor as the proportional ratio of soils with different resistivity practically does not affect the final result. This fact may mislead specialists, since the results obtained may differ significantly from what is observed in practice after the installation of GDs. The study proposes a calculation method and shows a fairly good convergence of the results with experimental data, and defines a further direction in optimizing calculation methods GDs.
Improving protection of medium voltage networks
Authors: Piskunov Sergey , Mokeev Alexey
Published: November 2024

This paper presents an efficiency analysis of medium-voltage distribution network protection and considers directions for improving protection characteristics based on synchronized phasor measurement technology (SPM). The authors propose protection algorithms based on two- and multi-sided measurements of voltage and current synchrophasors and cite the advantages of combining local protection with centralized protection and wide area protection.
Medium voltage digital instrument transformer
Authors: Ulyanov Dmitriy , Plakidin Roman
Published: November 2024

Instrument transformers with digital output provides significant advantages, including those related to increased reliability of power system operation. With the appearance of digital instrument transformers, the topology of the measurement channel and the functional purpose of its components change. This paper considers some function migration examples from protection devices to the primary converter (digital current and voltage transformer). Combined digital transformers expand the application area of distance protection principles, increase the fault location accuracy, as well as improve sensitivity and speed of single-phase earth fault (SPF) protection in 6-35 kV networks.
The use of information and computing technologies in solving problems of monitoring and managing the condition of cable equipment to ensure their reliability and efficiency
Authors: Ivanova V. , Tsipkina V. , Mamadalieva U.
Published: November 2024

The article discusses the issues of integrating data on the condition of cable equipment through information and computing monitoring and management procedures. Possibility of using information and computing technologies in order to solve management of production and technological tasks of manufacturing cable products which are produced in cable factories of the Republic of Uzbekistan has been studied. The results of the work of the developed Integrated Technological Platform as a system combining heterogeneous information and computing resources of cable equipment units and involved production systems are presented.
Sustainable Analysis of Building Materials for Social Housing: A Comparative Study of Embodied Energy of Concrete and Glued-Laminated Timber (GLT) Structures
Authors: Vieira Talita Dias , de Las Casas Estevam Barbosa , Aguilar Maria Teresa Paulino
Published: November 2024

This study aims to conduct a sustainable comparative analysis of embodied energy between different materials to produce social buildings in Brazil. The study compares structures and enclosure made of glued laminated timber (GLT) and reinforced concrete with enclosure made of ceramic block masonry to produce the same 48m² single-family housing unit following the COHAB MG standard. The accounting of materials used for building production was made through a BIM platform, and subsequently, total embodied energy was calculated, weighted according to the amount of each material used. Results indicates that buildings constructed with GLT in Brazil can achieve up to a 40% reduction in total embodied energy when compared to the traditional construction model of reinforced concrete and red clay blocks.
Towards scalability for metal halide perovskites photovoltaics
Authors: De Luca Daniela , Bruno Annalisa
Published: November 2024

Perovskite solar cells (PSCs) have gained significant attention in recent years due to the inherent properties of perovskite materials, such as bandgap tunability, high tolerance to defects in the structure, high light absorption, efficient charge transportation, flexibility, and cost-effectiveness. Although for a long time the development of PSCs has relied primarily on solution-based coating techniques, the recent advances in the field of PSCs have moved the attention of both researchers and companies toward thermal evaporation (TE) techniques, especially due to the high compatibility of these processes with the industrial production of PSCs. Indeed, TE has many advantages, such as high reproducibility, film uniformity, low material consumption, absence of toxic solvents, and easy scalability of the device. In this review, after a brief overlook of the most popular solution-based PSC fabrication methods, we illustrate the TE technique for small and large areas.
Bilan d’imagerie radiographique axiale chez le cheval
Authors: de Fourmestraux Claire , Bouillaut Carla
Published: November 2024

Du fait des avancées récentes des modalités d’imagerie en équine, notamment en radiographie numérique, la radiographie des régions axiales permet l’acquisition d’images de haute qualité. Il devient alors possible d’imager la colonne vertébrale au niveau cervical et thoraco-lombaire de façon standardisée. Cela permet d’obtenir un bilan radiographique complet rendant possible une évaluation ostéo-articulaire complète et précise au moment de la réalisation de l’examen. Son interprétation nécessite la maîtrise de l’anatomie de la région ciblée, mais également de la technique d’acquisition de l’image radiographique et des principes de radioprotection. Ces bilans d’imagerie doivent être interprétés à la lumière de l’évaluation globale du cheval, afin de faire le lien entre les lésions observées et leur réelle implication clinique. L’examen radiographique apporte de nombreuses informations, mais peut ne pas s’avérer suffisant pour conclure. D’autres techniques d’imageries avancées complémentaires peuvent être nécessaires afin d’aboutir au diagnostic. L’examen radiographique reste néanmoins l’examen complémentaire dit de « première ligne » pour évaluer le squelette axial du cheval.
Anesthésie intrasynoviale du pied du cheval
Authors: Duarte Castro Daniela
Published: November 2024

L’anesthésie intrasynoviale du pied est utilisée comme outil de diagnostic des boiteries. Elle permet de déterminer la présence ou l’absence de douleurs localisées au niveau du pied et provoquées par des blessures traumatiques ou des maladies impliquant des structures de l’articulation interphalangienne distale ou de la bourse naviculaire [5].

Pour le pied, deux anesthésies intrasynoviales sont principalement réalisées : celle de l’articulation interphalangienne distale (AIPD) et celle de la bourse naviculaire. L’anesthésie intrasynoviale de l’articulation interphalangienne distale aura un effet sur cette articulation, la bourse naviculaire, l’os naviculaire et ses ligaments suspenseurs, la région de la pointe de la sole et, pour la plupart des chevaux, la partie du tendon fléchisseur digital profond située dans le pied [6]. L’anesthésie de la bourse naviculaire permet de différencier la douleur localisée dans la bourse de celle provenant de l’AIPD ; elle peut également désensibiliser la région de la mamelle de la sole [3]. Dans les deux cas, la diffusion du produit est à prendre en compte lors de l’interprétation de la suppression de la douleur des structures pouvant être impliquées.

Cet article cherche à décrire succinctement les techniques permettant d’effectuer correctement cette procédure, en décrivant étape par étape et en donnant des recommandations pour la pratique.
Recent Advances in Combining Photo- and N-Heterocycle Nitrenium Catalysis
Authors: Tu Yong-Liang , Chen Xiang-Yu , Li Xiang
Published: November 2024

N-Heterocyclic nitreniums (NHNs) are isoelectronic and isostructural analogues of N-heterocyclic carbenes (NHCs). Unlike NHCs, NHNs are much less developed. While a comprehensive understanding of NHN reactivity remains elusive, recent advancements have demonstrated their utility as Lewis acid catalysts, photoreductants, and photooxidants, leading to several reaction patterns. In this short review, we focus on the applications of NHNs in photoredox reactions. We also discuss the mechanisms behind these transformations and outline future research directions.

1 Introduction

2 Application of N-Heterocyclic Nitreniums as Photoreductants

3 Application of N-Heterocyclic Nitreniums to Facilitate Photohomolysis

4 Application of N-Heterocyclic Nitreniums as Photooxidants

5 Conclusion
Revision of Hip Luxation in a Canine Total Hip Replacement Caused by a Greater Trochanteric Fracture Secondary to an Inflammatory Granuloma
Authors: Bassanino Jean , Guiot Laurent P.
Published: November 2024

A hip luxation 3 years following a cementless total hip replacement was diagnosed in a 4.7-year-old neutered male Lagotto Romagnolo that presented with a non-weight-bearing left pelvic limb lameness. Orthogonal radiographs revealed a left hip luxation and an osteolytic fracture of the greater trochanter. A mass consistent with an inflammatory granuloma was identified on preoperative computed tomography scan. Surgical revision consisted of granuloma excision, replacement of the loose acetabular cup, and repair of the femoral fracture with a locking plate. Fracture biology was augmented with the use of recombinant human bone morphogenetic protein 2 (rhBMP2) impregnated collagen sponge applied around the acetabulum and femoral fracture site. Osteointegration of the prosthetics and fracture healing were documented within 3 months of revision. Long-term follow-up at 3 years postrevision showed normal limb usage and no further evidence of total hip replacement complication.
Epidemiology of Acute Infectious Diarrhea-Associated Viruses in Children in Hangzhou, China, 2023
Authors: Guo Ya-jun , Li Lin , Lai Qin-rui , Li Wei
Published: November 2024

Objective To investigate the epidemiological characteristics of children infected with diarrheal virus in Hangzhou, China, 2023.

Methods From January 2023 to December 2023, 20,939 stool samples from children with acute infectious diarrhea were collected for the detection of rotavirus A and human adenovirus (HAdV), using latex agglutination detection kits; 7,584 stool samples were collected for the detection of norovirus, using real-time polymerase chain reaction reagent.

Results A total of 639 (3.0%, 639/20,939) tested positive for rotavirus A, and 1,201 (5.7%, 1,201/20,939) positive samples were detected by colloidal gold method. The positive rates of norovirus were 42.2% (3,203/7,585). Among all age groups, the rotavirus A positive detection rate was the highest in participants aged 3 to 6 years (6.46%, 260/4,024). The monthly distribution of patients with rotavirus A showed that the number of cases was the lowest in October (0.45%, 8/1,779) and reached the peak in April (7.97%, 144/1,806). The highest and lowest positive rates among all age groups for HAdV were found in children aged 3 to 6 years(8.27%, 333/4,024) and in those aged 0 to 6 months (2.21%, 60/2,717). The monthly positivity rates of HAdV spanning from January to November 2023 were 1.38, 1.44, 2.34, 3.65, 6.64, 7.71, 7.54, 7.13, 6.82, 4.15, and 6.50%, and reached the peak in December (8.17%). For norovirus, children aged 1 to 3 years had the highest positive detection rate (57.95%, 1,349/2,328), while infants aged 0 to 6 months had the lowest positive detection rate (19.60%, 205/1,046). The results show that January had the lowest number of cases (14.63%, 6/41), while September had the highest (50.51%, 545/1,079).

Conclusion The detection rate of rotavirus A and HAdV was highest among participants aged 3 to 6 years, whereas the detection rate of norovirus was highest among those aged 1 to 3 years. The monthly distribution peaks for the three enteric viruses varied significantly.
Effect of chemical segregation on accuracy of local lattice distortions determination by pair distribution functions
Authors: Hu Yao , Guo Sheng , Colliander Magnus Hörnqvist
Published: November 2024

Local lattice distortion (LLD) is a salient feature of bcc-structured refractory high-entropy alloys (RHEAs), closely associated with their mechanical properties. To quantify the extent of LLDs in RHEAs, the pair distribution function (PDF) analysis has been identified as a promising approach. However, the commonly observed chemical segregation within these alloys introduces challenges in accurately determining LLDs. In this study, the effect of chemical segregation on LLD quantification was investigated through fitting simulated two-phase composite PDFs, representing segregated microstructures, with a single-phase model and evaluating the errors to assess the accuracy and reliability of small-box analysis in this context. The results show that the errors introduced by chemical segregation increase with increasing lattice parameter difference, and the fitting quality gradually deteriorates to a point where it no longer adequately describes the data. We found that the lattice parameter difference should be below 1% for precise and reliable LLD measurements in bcc-structured RHEAs. Additionally, we observed that while the scattering length variation due to segregation does affect LLD quantification, its effect is comparatively minor.
Comparison of suckling and artificial rearing on calf growth and milk requirements in pastoral dairy systems
Authors: Bryant Racheal H. , Beckett Paige , Tey Lucas , Burgess Riki , Curtis Jeffery , Heiser Axel , Turner Sally-Anne , Hodgkinson Alison J.
Published: November 2024

Context Dairy calf-rearing practises have the potential to influence profitability through milk requirements at rearing, and affect lifetime productivity and market access from an animal-welfare perspective. Aims The aim of this research was to compare calf growth and milk requirements by using conventional artificial rearing (AR) and restricted milk allocation with AR and high milk allocation or suckled calves. Methods Forty-five Friesian × Jersey calves were allocated to be either AR on 6 L/calf.day, (ARC) or 12 L/calf.day, (ARH), or suckled with dams in a cow–calf contact system using partial contact (15 h/day, CCC). AR calves were fed, and intake measured, using an automatic feeder, whereas CCC calves had access to their dams between 1500 hours and 0600 hours. Calves were transitioned off milk, once they reached at least 75 kg liveweight (LW), by gradually reducing their milk allocation (AR) or reducing access to their dam (CCC). Key results Milk consumption for ARH was greater than for ARC calves (382 vs 450 L/calf, P < 0.05), whereas for CCC calves milk-yield difference between dams for the control and suckling groups during the suckling period and over the full season was 706 and 1048 L/cow respectively. There was no difference in weaning weight of calves (87 ± 1.7 kg LW), but, owing to differences in pre-weaning growth rate, age to weaning was youngest (P < 0.05) for CCC (55 days), followed by ARH (62 days) and ARC (73 days). Respective growth rates between birth and weaning (P < 0.001) for CCC, ARH and ARC calves were 0.955, 0.873 and 0.755 ± 0.028 kg/day. Although there was a growth check among CCC calves during the weaning period, there were no post-weaning differences in growth rate among the groups. Conclusions Increasing milk allowance had the benefit of improving calf pre-weaning growth rate, giving the option of weaning calves either earlier or when heavier. However, milk yield losses under suckling systems may be too high to warrant the elevated pre-weaning growth of calves. Implications The costs–benefits of high milk allocation or suckling systems need to be ascertained over the lifetime of the animals to assess long-term survival and productivity outcomes.
VEGF inhibition increases expression of HIF-regulated angiogenic genes by the RPE limiting the response of wet AMD eyes to aflibercept
Authors: Sharma Deepti , Lau Evan , Qin Yu , Jee Kathleen , Rodrigues Murilo , Guo Chuanyu , Dinabandhu Aumreetam , McIntyre Emma , Salman Shaima , Hwang Yousang , Moshiri Ala , Semenza Gregg L. , Montaner Silvia , Sodhi Akrit
Published: November 2024

Neovascular age-related macular degeneration (nvAMD) is the leading cause of severe vision loss in the elderly in the developed world. While the introduction of therapies targeting vascular endothelial growth factor (VEGF) has provided the first opportunity to significantly improve vision in patients with nvAMD, many patients respond inadequately to current anti-VEGF therapies. It was recently demonstrated that expression of a second angiogenic mediator, angiopoietin-like 4 (ANGPTL4), synergizes with VEGF to promote choroidal neovascularization (CNV) in mice and correlates with reduced response to anti-VEGF therapy in patients with nvAMD. Here, we report that expression of ANGPTL4 in patients with nvAMD increases following treatment with anti-VEGF therapy and that this increase is dependent on accumulation of hypoxia-inducible factor (HIF)-1α in response to inhibition of VEGF/KDR signaling in the retinal pigment epithelium (RPE). We therefore explored HIF-1 inhibition with 32-134D, a recently developed pharmacologic HIF-inhibitor, for the treatment of nvAMD. 32-134D prevented the expression of both VEGF and ANGPTL4 and was at least as effective as aflibercept in treating CNV in mice. Moreover, by preventing the increase in HIF-1α accumulation in the RPE in response to anti-VEGF therapy, combining 32-134D with aflibercept was more effective than either drug alone for the treatment of CNV. Collectively, these results help explain why many patients with nvAMD respond inadequately to anti-VEGF therapy and suggest that the HIF inhibitor 32-134D will be an effective drug—alone or in combination with current anti-VEGF therapies—for the treatment of patients with this blinding disease.
Aerodynamic efficiency explains flapping strategies used by birds
Authors: Johansson L. Christoffer
Published: November 2024

A faster cruising speed increases drag and thereby the thrust (
T
) needed to fly, while weight and lift (
L
) requirement remains constant. Birds can adjust their wingbeat in multiple ways to accommodate this change in aerodynamic force, but the relative costs of different strategies remain largely unknown. To evaluate the efficiency of several kinematic strategies, I used a robotic wing [E. Ajanic, A. Paolini, C. Coster, D. Floreano, C. Johansson,
Adv. Intell. Syst.
5
, 2200148 (2023)] and quantitative flow measurements. I found that, among the tested strategies, changing the mean wingbeat elevation provides the most efficient solution to changing thrust-to-lift ratio (
T
/
L)
, offering insight into why birds tend to beat their wings with a greater ventral than dorsal excursion. I also found that although propulsive efficiency (η
p
) may peak at a Strouhal number (
St
, measure of relative flapping speed) near 0.3, the overall efficiency of generating force decreases with
St
. This challenges the expectance of a specific optimal
St
for flapping flight and instead suggest the chosen
St
depends on
T
/
L
. This may explain variation in preferred
St
among birds and why bats prefer flying at higher
St
than birds [G. K. Taylor, R. L. Nudds, A. L. Thomas,
Nature
425
, 707–711 (2003)], since their body shape imposes relatively higher thrust requirements [F. T. Muijres, L. C. Johansson, M. S. Bowlin, Y. Winter, A. Hedenström,
PLoS One
7
, e37335 (2012)]. In addition to explaining flapping strategies used by birds, my results suggest alternative, efficient, flapping motions for drones to explore aiming to extend their flight range.
Flexibility and sensitivity in gene regulation out of equilibrium
Authors: Mahdavi Sara D. , Salmon Gabriel L. , Daghlian Patill , Garcia Hernan G. , Phillips Rob
Published: November 2024

Cells adapt to environments and tune gene expression by controlling the concentrations of proteins and their kinetics in regulatory networks. In both eukaryotes and prokaryotes, experiments and theory increasingly attest that these networks can and do consume biochemical energy. How does this dissipation enable cellular behaviors forbidden in equilibrium? This open question demands quantitative models that transcend thermodynamic equilibrium. Here, we study the control of simple, ubiquitous gene regulatory networks to explore the consequences of departing equilibrium in transcription. Employing graph theory to model a set of especially common regulatory motifs, we find that dissipation unlocks nonmonotonicity and enhanced sensitivity of gene expression with respect to a transcription factor’s concentration. These features allow a single transcription factor to act as both a repressor and activator at different concentrations or achieve outputs with multiple concentration regimes of locally enhanced sensitivity. We systematically dissect how energetically driving individual transitions within regulatory networks, or pairs of transitions, generates a wide range of more adjustable and sensitive phenotypic responses than in equilibrium. These results generalize to more complex regulatory scenarios, including combinatorial control by multiple transcription factors, which we relate and often find collapse to simple mathematical behaviors. Our findings quantify necessary conditions and detectable consequences of energy expenditure. These richer mathematical behaviors—feasibly accessed using biological energy budgets and rates—may empower cells to accomplish sophisticated regulation with simpler architectures than those required at equilibrium.
BSN: The First Photometric Analysis of Contact Binary Systems V1961 Cyg and V0890 Lyr
Authors: Baudart Sabrina , Poro Atila
Published: November 2024

We presented the first photometric analysis of the V1961 Cyg and V0890 Lyr binary systems. We observed and analyzed these systems at an observatory in France as part of the Binary Systems of South and North (BSN) Project. We extracted and collected the times of minima from the observations and literature and presented a new ephemeris for each system. Due to the few observations about these systems over the years, both O–C diagrams were fitted linearly. The PHysics Of Eclipsing BinariEs (PHOEBE) Python code and the Markov Chain Monte Carlo (MCMC) method were used for light curve solutions. The light curve solution required a cold starspot on the hotter component in the V1961 Cyg binary system. We compared and have close agreements between our mass ratios’ results from the light curve analysis processes and a new method based on the light curve derivative. We estimated the absolute parameters using an empirical relationship between the semimajor axis and orbital period for contact binary systems. The results show V1961 Cyg and V0890 Lyr are W-type contact binary systems. We displayed stars and systems’ positions in the M–L, M–R, and

log

M

tot

−

logJ

0

diagrams. We also presented a new relationship between mass ratio and luminosity ratio.
Modelled Cost Reductions for the X-Rotor Offshore Wind Turbine
Authors: Devoy McAuliffe F , Anderson F , Carroll J , Murphy J
Published: November 2024

The XROTOR project is developing an innovative turbine (X-Rotor Concept - XRC) that is a Vertical Axis Wind Turbine (VAWT)/Horizontal Axis Wind Turbine (HAWT) hybrid. The objective of this paper is to assess the XRC Levelised Cost of Energy (LCoE), applying different sensitivity analysis to determine a realistic LCoE range. This will then be compared with LCoE estimates for three traditional HAWT drivetrain configurations to evaluate the potential cost savings for the XRC.

The paper considers a hypothetical farm of 100x5MW XRCs on generic monopiles, 100km from shore and commissioned in 2030 with a 30-year project. Analysis uses the University of Strathclyde Operation and Maintenance (O&M) model and an LCoE tool developed by University College Cork to calculate results. Sensitivity analysis varies key cost driving elements and uncertain inputs including the O&M strategy, distance from shore and the financial assumptions to determine an optimised LCoE estimated range. Results for the XRC are then compared with estimates derived using the same methodology for the HAWT configurations.

Analysis indicates that the novel design may facilitate cost reductions, reducing OPEX by removing heavy components that would require costly heavy lift vessels to maintain. It also removes the failure modes around the gearbox, multi-pole generator and yaw system. The XRC could also reduce the capital cost of drivetrains through a power take-off approach that does not require a gearbox or a multi-pole generation but achieves comparable levels of power conversion. Ultimately the XRC could achieve LCoE cost reductions of 10-19%, compared with the traditional HAWTs. Further savings are considered possible but require additional design and analysis that are outside the scope of this paper.
Influence of wind farm fault current control strategies on distance protection during unsymmetrical faults
Authors: Holdyk A. , Suul J. A. , Marvik J. I.
Published: November 2024

This paper evaluates the performance of distance protection near a wind farm with type IV wind turbines with various basic fault current control strategies implemented in the power converters. The considered fault control strategies include control of purely positive sequence currents or combined positive and negative sequence currents for reactive power support of various magnitudes. A multi-variable study is performed in PSCAD to show performance of a basic algorithm of distance protection at a 420 kV line in a vicinity of the wind farm. The results show that the majority of relay failures occur for phase-phase-ground faults, that reactive current control has less influence in strong grid than in weak grid, and that standard wind turbine fault control procedure of providing balanced current might result in fault currents much smaller than maximum allowed (usually 1.2 pu).
Using Large Language Models to Recommend Repair Actions for Offshore Wind Maintenance
Authors: Walker C , Rothon C , Aslansefat K , Papadopoulos Y , Dethlefs N
Published: November 2024

The Offshore Wind (OSW) industry is experiencing significant expansion, resulting in increased Operations & Maintenance (O&M) costs. Intelligent alarm systems offer the prospect of swift detection of component failures and process anomalies, enabling timely and precise interventions that could yield reductions in resource expenditure, as well as scheduled and unscheduled downtime. This paper introduces an innovative approach to tackle this challenge by capitalising on Large Language Models (LLMs). We present a specialised conversational agent that incorporates statistical techniques to calculate distances between sentences for the detection and filtering of hallucinations and unsafe output. This potentially enables improved interpretation of alarm sequences and the generation of safer repair action recommendations by the agent. Preliminary findings are presented with the approach applied to ChatGPT-4 generated test sentences. The limitation of using ChatGPT-4 and the potential for enhancement of this agent through re-training with specialised OSW datasets are discussed.
Efficient calculation of deformation and FEM stress for substructures of floating wind turbines
Authors: Bredmose H. , Hansen A.M. , Fiskvik S. , Merino D. , Li H. , Gao Z.
Published: November 2024

Design tools for floating wind turbines must be able to quantify the effects of elastic substructure flexibility. The implementation in HAWC2 is here validated against a physical model test with a generic floater. Next, the detailed stresses in the substructure require Finite Element Modelling (FEM). When the deformations are small, linear analysis is sufficient and superposition can be utilized. Thus following modest pre-computation, stress time series for any random realization can be achieved efficiently through influence functions and FFT based transfer functions. We present a proof of concept here.
Mooring line materials for mini-TLP platforms
Authors: Papadopoulou S , Trompouki A , Tsakalomatis D , Peppas A
Published: November 2024

The present paper aims to compare the different types of mooring lines and materials with respect to motions and performance of a mini-Tension-Leg Platform. FloatMast®, that has been deployed in the Aegean Sea and completed a 1-year successful offshore site assessment, is a mini TLP and its structural model was used to evaluate the different mooring systems. Synthetic ropes, as alternative to wire ropes, have been introduced recently for mini TLPs, and their performance in these types of offshore platforms is of notable interest, both performance and marketwise. The simulations were conducted using DNV’s software SESAM suite and address operational as well as extreme wave conditions. The results present, for all materials, the performance of each mooring line in terms of axial tension and platform movement.
Controller influence on the fatigue of a floating wind turbine and load case impact assessment
Authors: Sánchez Alberto , Vicinay Mikel , Sánchez Miren , Flores Imanol , López-Queija Javier , Busturia Jesús
Published: November 2024

The assessment of fatigue in Floating Offshore Wind Turbines (FOWT) is a complex and widely debated topic within the industry. The dynamic behaviour of FOWT is heavily influenced by sea and wind conditions, which can significantly challenge the achievement of structural integrity and performance objectives. Additionally, the interaction of blade aerodynamics and control strategies further complicates this assessment. This study evaluates the impact of different control strategies and blade formulations on both the expected real performance and the estimated fatigue of FOWT. While control strategies can influence both the expected real performance and fatigue estimations, the blade formulation primarily affects the accuracy of performance estimations without altering the actual expected performance. However, the blade formulation can significantly modify the fatigue estimation of the FOWT. Damage Equivalent Loads (DEL) calculation is a commonly used method for assessing fatigue. However, while individual DEL calculations are useful, they do not show the contribution of each load case to the overall fatigue, since they do not consider the probability of occurrence. Therefore, this paper proposes a new method of normalising DEL, allowing for comparison of loading cases and identifying operational areas that pose greater fatigue risks. The findings underscore the substantial impact that different control strategies and blade designs can have on fatigue and overall performance. Essentially, there is a trade-off between maximising power output and minimising fatigue damage.
YOLOv7-based insulator defect detection with progressive feature fusion and DFC attention
Authors: You Xilai , Ma Jianqiao
Published: November 2024

With the development of smart grids, drones have been widely used for inspecting power transmission lines, generating a large amount of insulator image data. Relying on manual inspection for this task results in a huge workload and the risk of missed detections due to human fatigue. Here, we propose an improved model based on YOLOv7-Tiny. First, we replace the activation function with the funnel activation function to optimize the activation domain dynamically. Second, we introduce a lightweight DFC attention mechanism. Experimental results show that the improved model achieves a detection accuracy and recall rate of 96.4% and 92.5%, respectively.
A new DC bus voltage control strategy for energy routers based on distributed coordination optimization
Authors: Chen Shiwei , Lei Shi , Xia Xuhua
Published: November 2024

The types of power ports of energy routers at the side of the distribution network platform are complex and have different characteristics, which makes the operation conditions of energy routers complex and changeable. Although many pieces of literature have proposed more relevant control strategies to effectively realize the efficient and stable operation of energy routers under the two basic working conditions of grid-connected and isolated islands. However, when considering various complex operating conditions such as start-up, overload/overcharge, sudden failure of distribution network, grid-connected, and inter-island switching, the reliable operation of the existing energy routers is still faced with great challenges. In this paper, a DC bus voltage control strategy based on distributed coordination optimization is proposed for typical operating conditions of energy routers. Simulation results show that this strategy can effectively achieve the DC bus voltage control performance of energy routers under various burst operating conditions and strengthen the robustness of output voltage of energy routers under isolated islands.
Refined transmission line ice-cover prediction model and optimization study
Authors: Tian Maojie , Yang Guozhu , Sun Shirui , Sun Huamin , Liu Jingru
Published: November 2024

This study aims to develop a fine-grained transmission line ice-cover prediction model and conduct an optimization study. Ice cover is one of the important factors leading to transmission line accidents, so accurately predicting the ice cover of transmission lines is crucial to ensure the safe operation of power grids. In this paper, an efficient ice-cover prediction model is constructed based on advanced machine learning algorithms and optimization methods and is validated and optimized with a large amount of experimental data. The results show that the proposed model has high accuracy and prediction capability in ice cover prediction, which provides important support for the safe operation of transmission lines.
Force analysis and improvement of main transformer bushing terminal structure
Authors: Duan Ruofei , Pei Hao , Shi Kaiyuan , Wang Dayong , Yu Haiyang , Wang Yuping , Zhong Haoxin
Published: November 2024

After investigation, it was found that due to natural environmental conditions such as rain and snow temperature, equipment such as down conductor above the terminals, and natural swings of wires, the terminal blocks of the down conductor bushing on the high voltage side of the main transformer of a 500kV substation will deteriorate and deform. Following the force analysis and experiment on the down conductor bushing terminal block on the high voltage side of the main transformer, it is found that the weak structure of the bushing terminal block lies in the vertical orientation of the terminal and the connection point of the transverse structure, and its horizontal external force limit value is 1.91KN. In this paper, it was finally decided to improve the terminal structure by erecting diagonal supports between the vertical and transverse structures of the terminals. The improved terminal block can be subjected to an external force of 5KN horizontally, and the terminal shape is within the safe range. It can ensure the safety and stability of the main transformer bushing terminal block.
Improved sparrow algorithm to optimize kernel extreme learning machines for lithium battery status of health estimation on incremental capacity curve
Authors: Ni Yiwei , Ding Xuqiang , Wang Qi
Published: November 2024

The advancement of new energy vehicles and energy storage devices has increasingly demanded a more accurate state of health estimation for lithium batteries. Data-driven models are gradually widely used but still have the problems of long iteration time, low accuracy, and unreliable selection of feature factors. Thus, to promote the application of data-driven models in estimating the health state of lithium batteries, this paper proposes a multi-method improved sparrow algorithm optimized kernel extreme learning machine framework for lithium battery health state estimation. To improve the speed and accuracy issues of the data-driven model, this paper selects the kernel extreme learning machine as the network model and the improved sparrow algorithm using chaotic mapping and self-designed exponential weight factors as the optimization algorithm for automatic parameter search to achieve high accuracy and speed. Secondly, to strengthen the reliability of data feature factor selection, multiple feature factors are selected in the incremental capacity curve to improve the stability of feature factors. Finally, the rapidity and reliability of the proposed model on the SOH prediction of lithium batteries are verified by experiments, which provides an effective way to manage lithium batteries healthily.
Research progress on topology and energy management of fuel cell hybrid power ships
Authors: Tian Chenglong , Zhang Li , Zou Liang , Liu Xingdou
Published: November 2024

With the increasing awareness of environmental protection, the maritime industry is moving towards green and low-carbon development. Fuel cells, due to their pollution-free and high-efficiency characteristics, are one of the key technologies driving the green transformation of traditional ships. However, fuel cells have relatively soft output characteristics and often require other energy storage components to provide supplementary power. This paper reviews the types, advantages, and disadvantages of the topologies of fuel cell hybrid power ships, analyses the current development status of energy management goals and methods, and finally provides an outlook on the development of fuel cell hybrid power ships.
Design of a two-stage photovoltaic grid-connected system with dual closed-loop control
Authors: Niu Jianfeng
Published: November 2024

This paper designs a two-stage photovoltaic grid-connected system with dual closed-loop control, cascading the topological structures of photovoltaic cells, boost chopper circuits, and inverter circuits. The front-stage boost chopper circuit control utilizes the incremental conductance method to achieve maximum power point tracking control. The rear-stage inverter circuit employs a dual closed-loop control system with an outer voltage loop and an inner current loop, incorporating a proportional-integral controller, to ensure stable DC-side voltage and unity power factor for grid connection. A simulation model of the two-stage photovoltaic grid-connected system designed in this paper was constructed and analyzed through simulation runs. The firmness of the DC-side voltage and the achievement of unity power factor during grid connection confirmed the operability and resultiveness of the cascaded topology and the control method.
A distributed photovoltaic short-term power forecasting model based on lightweight AI for edge computing
Authors: Fan Yuanliang , Wu Han , Lin Jianli , Li Zewen , Li Lingfei , Huang Xinghua , Chen Weiming , Chen Beibei
Published: November 2024

In recent years, an immense amount of distributed photovoltaics are integrated into low-voltage distribution network, producing a substantial volume of operational data. The centralized cloud data center cannot process massive amounts of data precisely and promptly. Therefore, the operational status of distributed photovoltaic systems in low-voltage distribution network becomes difficult to predict. However, edge computing in the distribution network enables local data processing to improve the forecasting service’s real-time reliability. In this regard, this paper proposes a distributed photovoltaic short-term power forecasting model based on lightweight AI algorithms. Firstly, based on the Pearson correlation coefficient method, an analysis is conducted on the historical operational data in the network to extract important meteorological features correlated with the photovoltaic power output. Secondly, a distributed photovoltaic power forecasting model for the distribution network is constructed based on the Xception and attention mechanism. Finally, the model is trained using pruning, which removes redundant parts of the model, resulting in a compact and efficient forecasting model. By validating real-world datasets, the results demonstrate that the model presented in this article has a smaller size and higher forecasting accuracy than other state-of-the-art forecasting models.
Voltage control strategy of output bus of grid-connected port of energy router based on energy feedback
Authors: Chen Shiwei , Shen Ying , Xia Xuhua
Published: November 2024

The remaining power conversion ports are equivalent to constant power loads for the grid-connected port of the voltage source. The negative impedance characteristics of the constant power loads will worsen the voltage source characteristics of the grid-connected port and even cause system instability. According to the influence mechanism of constant power load on the DC bus voltage control performance during grid-connection, a new voltage control strategy based on energy feedback is proposed in this paper. The simulation results show that the proposed control strategy can more effectively reduce the negative impedance characteristics of the energy router’s constant power load and improve the bus voltage’s control performance compared with the existing control strategies.