bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Brief Review of Smart Control of Renewable Energy Power Generation
Authors: Xiao Yu , Xia Chunni , Cai Qinqin , Zhu Yongqiang 
Published: June 2021

Abstract
The smart control strategy in the operation of renewable energy station is of great significance to alleviating the shortage of fossil energy, improving the efficiency of renewable energy utilization and the safe operation of power system. Firstly, this paper took the renewable energy stations represented by wind and solar energy as the research object, summarized the smart control strategy of single unit power generation, and elaborate introduced the mechanical structure control, maximum power point tracking control and virtual synchronous machine control in electrical converter level. Secondly, the self-protection control of renewable energy power generation station in the case of power system faults were analysed. The key issues involved in the low voltage ride-through, high voltage ride-through, protection circuit of rotor side, stator side and converters were summarized. Thus, a brief overview of smart control of renewable energy station operation is presented in this paper, hoping to provide technical guide for prosperous development of renewable energy in the future.
Research on Magnetic Field Characteristics in DC Yard of Dinghai Converter Station Under Monopolar Grounding Fault
Authors: Bao Meng , Shen Hong , Li Jialiang , Huang Xianrui , Wang Qian 
Published: June 2021

Abstract
In Dinghai converter station of Zhoushan VSC-HVDC transmission project, 200 kV hybrid DC circuit breaker is used for the first time to realize DC side fault isolation. When DC side short circuit occurs, its fault current characteristics are different from those of AC substation and HVDC converter station, and the magnetic field interference to secondary equipment in DC yard is still unknown. In this paper, taking the single pole grounding short circuit fault with high probability in flexible DC power grid as an example, the electromagnetic transient simulation model of fault current in Dinghai converter station is established, and the time-domain current waveform is obtained. Then, the magnetic field calculation model of DC circuit breaker and other key electrical equipment is established, and the magnetic field of secondary equipment in DC yard is calculated based on Biot-Savart Law. The results show that the maximum magnetic field strength at the secondary equipment is 59 A/m, the waveform is ms level, and it is aperiodic. The distribution of magnetic field in DC yard varies between 3 and 346 A/m.
Research and Implementation of a Local Modification Method of Power System Topology Suitable for Large Power Grid Training Simulation System
Authors: Yang Xiaojun , Zhou Lijun , Wang Ruiqiang , Zhao Chengjie , Sun Xiaodi , Gao Feng 
Published: June 2021

Abstract
This paper proposes a local topology correction method for large power grid simulation. The analysis method of the local topology corresponding to the “open” and “close” events of the power equipment and the correction method of the corresponding node admittance matrix. This method is suitable for online analysis systems such as large power grid simulation systems. Finally, this paper verifies that the local topology correction method proposed in this paper greatly improves the topology analysis speed and calculation efficiency of the large power grid training simulation system.
Bidirectional Virtual Inertia Control Strategy for Interlinking Converter in Hybrid AC/DC Microgrid
Authors: Ma Zhen , E Lin , Deng Hongyuan , Wang Zhi , Zhu Yongqiang 
Published: June 2021

Abstract
The AC/DC hybrid microgrid can realize the power flow between the two sub-microgrids by controlling the interconnected converters connected to the AC and DC sub-microgrids, thereby improving the system’s ability to suppress power fluctuations. In order to achieve a reasonable power flow between the two sub-microgrids in the steady state and in the transient process, this paper analyzes that the traditional droop control of interconnected converter ( ILC ) pays less attention to the transient process of the hybrid microgrid. On the basis of virtual synchronous generator, a bidirectional virtual inertia control strategy for ILC is proposed. This control strategy can not only respond to the offset between the DC bus voltage and the AC frequency, but also achieve the goal of sharing the system power fluctuations between the two sub-microgrids in the steady state according to the voltage and frequency offset requirements. It can also respond to the DC bus voltage and The rate of change of the AC frequency realizes a reasonable inertial support between the two sub-microgrids in the transient process. In order to balance the transient target and steady-state target of the interconnected converter, this paper designs the parameters of the proposed control. Finally, a simulation model was built in PSCAD to verify the effectiveness of the proposed control strategy.
Electromagnetic design of high-speed permanent magnet synchronous motor for flywheel energy storage system
Authors: Wu Jiabin , Xu Zhenyao , Zhang Fengge , Tong Ningze 
Published: June 2021

Abstract
Flywheel energy storage system (FESS) has significant advantages such as high power density, high efficiency, short charging time, fast response speed, long service life, maintenance free, and no geographical environment restrictions. Motor is the energy conversion core of FESS and plays a significant role on system performance. In this paper, the design features of the motor for FESS are analyzed first. Then, a permanent magnet synchronous motor (PMSM) with a rated speed of 12000 rpm and a rated power of 250 kW is designed. Thirdly, aiming at the key problem of difficult heat dissipation of rotor, an improved rotor structure with “1” rotor permanent magnets layered and divided where placed in tangential and radial directions is proposed, which can reduce eddy current loss by 22.8%. Finally, based on Ansys FEM software, electromagnetic characteristics of the designed motor at no-load and full-load conditions are simulated and analyzed. The results show that the designed electromagnetic scheme meets the expected performance requirements and has guiding significance for prototype.
SFRA Test Method Application for Turbo Generator Rotor Winding
Authors: Mubarak Zakky , Supriyanto Eko 
Published: June 2021

Abstract
The development of technology in the present makes the testing method for analysis to know the defect to insulation winding in rotating machines is varied. There are many specific testing tools to determine the damage. The authors of this paper conduct a preliminary study using sweep frequency response analysis (SFRA) to detect and find damage in the turbo generator rotor winding. SFRA is a test equipment performed on transformers based on the working principle of RLC which are Resistive, Inductive, and Capacitive. The importance of the damage identification process is needed to maintain reliable rotor generator and avoid catastrophic defect to equipment and losses to power plant. In one case study, the rotor generator experienced high vibration indication when operating in high reactive power and the SFRA test results on the rotor winding shows a mismatch between two curves. In another case, a mismatch of SFRA result showed winding deformation, such as coil elongation, without high vibration indication in rotor generator. After inspection, repair, measurement and testing, the SFRA method proves that it can show indications of defect without major dismantling.
A Fast Calculation Algorithm of Efficiency Map of Permanent Magnet Synchronous Machines Using Finite-element Method
Authors: Li Wei , Liang Hongwei , Liu Jun , Zhang Wenhao 
Published: June 2021

Abstract
A fast calculation algorithm of efficiency map of permanent magnet synchronous machines using finite-element (FE) method is proposed in this paper. The control strategy of the machine can be taken into account in the whole torque-speed operating region. The optimal current vector is obtained by using analytical calculations, where the material saturation is also included. By using the proposed method, only one run of time-stepping FE analysis is required below the rated speed. The calculation time of the efficiency map is much reduced compared to the conventional calculation method. An example is tested, and calculation results are given to verify the proposed method.
Picturing the thermodynamic universe with Frida Kahlo
Authors: Pereyra M , Botasini S , Cerdá M F , Méndez E 
Published: June 2021

Abstract
Bringing arts to the science classes remains as a challenging idea. The illustration of a concept with an original painting would bring unexpected advantages. Here we present the use of a painting of Frida Kahlo to illustrate the concept of the thermodynamic universe the surroundings. Such concept is not deeply treated in most textbooks, and it is essential now of analysis of a thermodynamic system. Because of the use of this visual aid, our students were able to distinguish several possible thermodynamic universes, depending on the objective of their study, gaining a more insightful approach than that usually obtained with classical pictographic representations in physical chemistry textbooks.
Determination of corrosion products for steam and flue gas injection environments using thermodynamic simulation
Authors: Moreno J , Santos L , Orozco-Agamez J , Ariza C , Muñoz S , Peña D 
Published: June 2021

Abstract
Thermal recovery processes using steam injection with combustion gases (flue gas) have shown positive results in the recovery of heavy crude oil over the conventional process, by integrating different recovery mechanisms. However, under the operating conditions, the injection of these fluids generates highly corrosive environments that have an impact on the deterioration of the materials, resulting in risks and operational costs. Therefore, it is necessary to determine the theoretical corrosion products that can be generated in these processes. This research focused on the study of API N-80 carbon steel exposed to a steam and flue gas atmosphere, at pressure and temperature conditions in the ranges of 800 psia - 1100 psia (55 bar - 75 bar) and 520 °F - 560 °F (270 °C - 290 °C) respectively. Based on this environment, to determine the theoretical corrosion products, a thermodynamic simulation stage was developed using HSC Chemistry software, which was used to generate Pourbaix, Ellingham and thermodynamic equilibrium diagrams. It was found that the main theoretical corrosion products corresponded to oxides, carbonates, and hydroxides, among which the significant presence of iron (III) oxide (Fe2O3), iron (II, III) oxide (Fe3O4) and iron carbonate (II) (FeCO3) was corroborated.
Fatigue study on AISI/SAE 1015 steel with shot peening under corrosive environments
Authors: Romero F , Pertuz A , Diaz J G 
Published: June 2021

Abstract
This work evaluates alternative four-point bending fatigue stress in 2 < pH < 4 corrosive media of AISI/SAE 1015 steel subjected to shot peening surface treatment. A tri factorial experimental design with replications was used. The intervening factors were: i) load levels, 0.96, 0.85, 0.73, 0.65; ii) corrosive media; pH2, pH4, ambient; iii) shot-peening surface treatment; without any shot peening, S230 shot peening and CW-41 shot peening, for which a total of 108 specimens were tested with a reliability level of 95% and a probability of failure of 3%. Tests were performed on a universal machine in a three-point bending assembly with an electro-pneumatic system. The cycle counting and control were performed by a programmable logic controller. The results of the stress-life method in each one of the scenarios show that the best condition was shown in the probes with shot peening S230 and CW-41 treatment under atmospheric conditions, where the material tends to increase its fatigue behavior; the number of cycles reached 36990 and 37773 respectively. The corrosive effect of pH2 and pH4 reduced on probes without shot peening treatment with a maximum of 9862 and 8670 cycles respectively; however, for S230 and CW-41 shots, an increase in cycle number in pH2 and pH4 was evidenced, with the best result for S230 shot at pH4 with a maximum range of 21568. Likewise, the fractography analysis shows mixed fractures with fatigue failure mechanism; the characteristics found were beach marks, secondary cracks, localized oxidation (filiform, plates, pitting, stress, and compression corrosion), nucleation, microvoids, cleavage facets, intergranular and transgranular cracks.
Study case: evaluation of pallets manufactured by structural foam with polietilene from analysis by the finite element method and mechanical tests
Authors: Bayona J A , Garnica H A , Luna J L , Juzga G A , Ortiz L R 
Published: June 2021

Abstract
This document presents the implementation of the methodology for the evaluation of non-metallic materials, through the modeling, simulation and diagnosis of components manufactured by the high-density polyethylene injection method called structural foam, where a mixture is made between an inert gas and polyethylene of two origins: a part of recycled material and the other part of new material. This type of manufacturing is carried out for the shaping of stowage-type components, for the transport of containers of liquid substances. For the evaluation of the Stowage, a simulation was carried out from a commercial modeling software, Autodesk Inventor, based on the geometry, the mixture of materials, the attachment points and border parameters, the location and type of loads to simulate, and the different ways in which the loaded stowage would be used. After this, mechanical tests were carried out to determine the properties of the materials in their different mixtures and a feedback process of the finite element model was carried out, thus obtaining results with a minimum error factor, and thus issuing a diagnosis, focused on which material mixing ratio was the most suitable, based on the critical points of the stowage, its stress and deformations, and its safety factor. Finally, the existence of imperfections (bubbles), typical of the manufacturing process, which tend to have an incidence as concentrators of intrinsic efforts, and as critical points, is considered.
Autoregressive modelling of chromatographic signals from urine samples for prostate cancer diagnosis
Authors: Soto-Vergel A J , Medina-Delgado B , Palacios-Alvarado W 
Published: June 2021

Abstract
This article evaluates autoregressive modeling as a feature extraction method in a database of chromatographic signals from urine samples for non-invasive diagnostic support of prostate cancer in response to the research question: Can chromatographic signals from urine be characterized and used as a non-invasive method for cancer diagnosis? For this purpose, a database of 18 patients, 9 diagnosed with prostate cancer and 9 control patients, is consolidated, statistical methods are implemented to generate autoregressive coefficients from the data signals, and finally, the principal component analysis technique is applied for cross-class classification. As a result, a correct classification was obtained in the total number of samples validating the autoregressive modelling as a feature extraction method in contrast to the conventional methodology usually followed in chromatographic signal processing.
Novel method for stress history analysis in normally consolidated clays
Authors: Martinez J H , Ruge J C , Rojas J P 
Published: June 2021

Abstract
The historical investigation of stresses in a clay material is essential to predict the compressible behaviour of a soil layer that, in most cases functions as a foundation support of superstructures. Because the stresses underwent in the geological past provide useful information to understand the response of the soil today. There are numerous methods for the interpretation of the preconsolidation stress, defined by the standard unidimensional consolidation test. The concept of preconsolidation stress is extremely useful in the geotechnical field to analyze and estimate settlements in a clay deposit, in addition to normalizing other parameters for comparative purposes. Through mineralogical analysis and consolidation tests based on different models for the estimation of the vertical consolidation coefficient, preconsolidation stress is evaluated by applying disparate constitutive methods. In order to observe the dispersion of results for a particular soil. A new technique is proposed for the determination of the preconsolidation stress prescribed in differential terms and with a high degree of objective interpretation.
Evaluation of sulfur dioxide in air quality from the emissions of vessels anchored in the Port of Rio de Janeiro, Brazil
Authors: Guimarães C S , Maia D R S , Maués C S 
Published: June 2021

Abstract
The navigation of waterway transport has increased significantly in the last decades in the world and Brazil contributes to this growth. Supply boat types used for logistical support the platforms demand the consumption of high-density oil for the propulsion of the main engines, auxiliaries, and boilers, which result in continuous emission of pollutants into the atmosphere, today considered one of the biggest polluters. Recent studies estimate the emission of pollutants up to 400 km from the coast, which demonstrates the direct impact on coastal communities. One way to assess the impact of these emissions is to use mathematical models that allow the effects of air pollutants to be calculated on the environment and in coastal regions, being a relevant tool for planning and regulation purposes. The main objective of this work was to provide an estimate calculation of sulfur dioxide emissions from vessels that are anchored in Guanabara Bay, Rio de Janeiro, Brazil, and understand the relative contribution of this pollutant in the context of its neighborhood. After the simulations, some calculations obtained were compared with the values monitored in nearby region, in order to estimate the contribution of sulfur dioxide emission in this region. The estimated contribution of sulfur dioxide in the evaluated region, varied from 1% to 80% from the comparisons with the monitored data.
Diagnosis of physical conditions for the implementation of a reverse logistics management model in a supply chain
Authors: Garzón-Agudelo P A , Palacios-Alvarado W , Medina-Delgado B 
Published: June 2021

Abstract
The objective of this research was to structure a Reverse Logistics Management model applied to the furniture sector in the city of San José de Cúcuta, Colombia, based on the identification and analysis of the current business practices adopted by the companies that are part of this sector. For this purpose, engineering methods and techniques were used to propose alternatives that contribute to achieve a competitive growth, a better use of resources and environmental impact through strategies for the reuse of products or materials that, based on their physical properties, represent the best feasibility conditions. The type of research used was descriptive, with a qualitative approach. The methods used for data collection were mainly surveys, interviews and direct inspection of the companies studied, which made it possible to evaluate the physical variables of the object of study. It was possible to demonstrate that furniture manufacturing companies can adopt better reverse logistics practices in the manufacturing processes through referencing and articulation with strategic allies in the distribution channels. It was possible to establish the importance of implementing this model as a strategy to diagnose physical conditions and improve production systems to achieve a more efficient use of physical manufacturing resources.
Design of sitting lower limb rehabilitation training robot
Authors: Nan Qin 
Published: June 2021

Abstract
Based on the theory of sports rehabilitation medicine, aiming at the needs of early, middle and late rehabilitation training of patients with lower limb paralysis, a sitting lower limb rehabilitation robot is designed to train muscles with impaired motor function of the limbs. The Innovative design of the lower limb rehabilitation training robot consists two parts. They are the lower limb rehabilitation mechanism and the seat auxiliary mechanism, which can restore and reconstruct the impaired motor function of patients to the greatest extent.
A extrusion die structure with four cavities in a die of Al-alloy screen frame
Authors: You peng Chen , Yu wen Deng , Gui hao Zhang 
Published: June 2021

Abstract
The importance of extrusion die with multi-cavities in a die was introduced, and a new die structure with four cavities in a die for the frame in the screen window of Al-alloy was presented. The selection of the structure parameters for the die were described, including the selection of the machine, the arrangement of porthole and the die hole, the optimization of parameters, the design of the chamber and the bearing belt etc. The ways of optimizing these parameters were presented. The method of checking the die strength was introduced. It was shown by the results that the structure is effective and worth promoting, and the structure can greatly improve the production efficiency and reduce costs. The aim is to extend the technology and the structure, provide reliable and valid reference data for the designers.
Research on Condition Evaluation of Gearbox Based on PCA-FCM
Authors: Wang Haitao , Fan Sixia , Wu Bin 
Published: June 2021

Abstract
In order to evaluate the state of the gearbox, this paper proposes to use PCA-FCM algorithm to divide the state of the gearbox. By decomposing the vibration signal of the gearbox and taking the principal component, the state of the gearbox is divided. At the same time, this paper considers the fuzzy partition and geometric structure partition of the data set to determine the classification, which is verified by the wind turbine gearbox simulation experiment platform. The experimental results show that the gearbox state assessment based on PCA-FCM algorithm can effectively divide and identify the operation state of the gearbox, which makes the operation state division of the gearbox more scientific, and provides a theoretical basis for subsequent fault diagnosis and maintenance strategy.
A New Virtual Environment System for Large-Scale Complex Products Assembly
Authors: Xiu Tian , Yue-dong Lang , Hong-wei Wu , Ying-xue Yao 
Published: June 2021

AbstractTo deal with the problems of complicated process, difficult operation and low efficiency for large-scale complex products assembly, a new Virtual Assembly Environment System (VAES) was proposed, which applies Virtual Reality (VR) technology in the process of assembly planning and training. A series of key technologies were proposed, such as parallel rendering, stereoscopic display, geometrical correction, walking machine. A stereo video generator was developed to maintain real-time display and decrease costs. A geometrical correction method based on NURBS surface was presented. The system was applied in the process of satellite assembly, the result showed that it was feasible for the related research and application.
Analysis of four-edge mill modality and stress deformation based on ANSYS
Authors: Qi Liu , Haodong Xu , Jianfeng Wang 
Published: June 2021

Abstract
In mechanical design, we often need to use CNC machining center, in which milling cutters are our indispensable and most common processing tools, milling machines. We often use two-edged milling cutters, three-edged milling cutters, four-edged milling cutters. In order to analyze the milling cutter, we need to draw the 3D modeling of the milling cutter in UG, import the 3D model into the workbench to analyze the tool finite meta, analyze a four-edged mill, analyze whether the natural frequency will resonate with the machine tool. Find 10th-order modes, stress analysis of tools, deformation analysis. Topology optimization is carried out to enhance existing effects, reduce costs and improve efficiency.