bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modelling and analysis of electrical performance outdoor glass insulator under various services and lightning impulse
Authors: Su TY , Yaakob SB , Ariffen AM 
Published: August 2023

Abstract
This paper is focus on modelling of glass type insulator with voltage rating of 275 kV. The glass insulators are still widely served in overhead transmission line because of its high dielectric strength capability. However, their outdoor application has resulted in the exposure to the various service conditions such as weather, pollution and lightning conditions. Further, the inclination effect of the insulator under the nominal voltage and lightning impulse is modelling through Finite Elementary Method (FEM). Then, the model of glass insulator is constructed in three different inclination angles by using the Ansys Maxwell 3D for simulation purpose. The results show the inclined insulator due to the wind load effect has the lowest breakdown voltage at most 53.33% compared with the vertical insulator. Under the outdoor environment factors such as humid, wet and contamination, the localized electric field and current density had increased significantly. Consequently, this situation may cause the power losses, localized heating effect also reduces the electrical performance of the insulators.
Dual Outputs Switch Mode Power Supply (DOSMPS) Utilizing Forward Converter Topology
Authors: Fauzi F , Udom U , Zaidi M E , Manaf N A A 
Published: August 2023

Abstract
Experimental works of dual, 5 volt DC outputs switch mode power supply (DOSMPS) is presented in this paper. To design, construct and evaluate the DOSMPS using forward converter topology are the objectives of this article. In this work, a 556 timer was picked as the pulse width modulator. The 556 timer was picked because it is widely used, cheap and capable of producing stable dual pulse width modulations. Since, this work targeted dual DC outputs, two forward converter circuits were built. However, switching frequencies at two transistors were controlled by only one 556 timer. The complete circuit of the DOSMPS consist of full bridge rectifier, smoothing capacitor, two high frequency transformers and two forward converter circuits. At the first stage of this work, the DOSMPS circuit was designed using Proteus software. Later, the complete DOSMPS circuit was constructed on two breadbroads after all of the electronic components and devices were available. Important parameters such as the input and output voltages and duty cycles were measured using digital oscilloscope and multimeter. Results from these measurements have shown that the designed circuit can convert single-phase 24 Vrms 50 Hz AC voltage input into dual and stable 5±0.1 V DC outputs. Also from this work, it was observed that, pulsed DC voltages with peak value of 2 V and frequency less than 20 kHz are sufficient in controlling the switching frequencies of both BJT transistors. This allows the regulation of the output voltage within the desired range. Analysis carried out after the measurements has shown close correlation between the theoretical and experimental results, where the calculated and measured switching frequencies had only deviated by 1.1%.
Lightning Impulse Voltage Stresses In Underground Cables
Authors: Laili M S , Fen C M L , Isa M , Arshad SNM , Zakaria Z N 
Published: August 2023

Abstract
Underground power cables are crucial for transmission and distribution. Lightning can stress their insulation, but not directly. So, impulse cable testing is studied. This research examines the cable’s transient response to standard and non-standard lightning impulse voltage waveforms. MATLAB Simulink was used to model a 132 kV wire with standard and non-standard impulse voltages. The IEC60060-1(2010) lightning impulse test uses a conventional waveform impulse voltage with a front time and a tail time of 1.2/50μs half value, while the non-standard test uses a front time and a tail time of 0.8/12s half value. Non-standard impulse waveforms are more accurate than standard waveforms. The impulse test voltage is four to five times the underground cable’s operational voltage and must withstand five applications without damage. Standard and non-standard impulse waveforms are injected with 132 kV and 550 kV to evaluate insulation failure or damage. Standard lightning and non-standard impulse voltage waveforms do not cause insulation failure or damage. When 132 kV and 550 kV are introduced into the normal and non-standard lightning impulse waveforms, the overshoot voltage increases. The peak voltage of a non-standard 550 kV impulse voltage waveform exceeds the IEC impulse withstand voltage. The finding shows that non-standard impulse voltage waves create increased cable voltage stress.
Control Method of Seamless Transfer from Grid-Connected Mode to Isolated Mode for Microgrid Demonstration
Authors: Wu MeiRong , Xue Fei , Ren Yong 
Published: August 2023

Abstract
It’s easy to cause transient oscillation problems when the microgrid transfers from the grid-connected mode to the isolated mode, so a control method of seamless transfers from the grid-connected mode to the isolated mode for microgrid demonstration is proposed. The switching control strategy of the outer loop controller for the master unit(s) makes the reference value of the current inner-loop controller the same when the microgrid transfers to isolated mode. While the switching control strategy of phase locked loop (PLL) uses an ample-hold assign the output angle of grid-connected PLL to the oscillator adopted by the microgrid in isolated mode at the switching moment. Finally, the sub-regional control strategy uses different control strategies to reserve more spinning capacity for the master unit(s) which divides the power balance into 3 regions. At last, the simulation is verified that the proposed control method not only realizes the seamless transfer from grid-connected operation to islanded operation for the microgrid but also improves the anti-disturbance ability of the microgrid in isolated mode.
Simulation of Spent Fuel Assembly Transport Vertical Drop Based on LS-DYNA
Authors: Wang Xiaoqi , Fan Youchen , Chi Qidong , Wang Hehui 
Published: August 2023

Abstract
The finite element technology is used to carry out the drop simulation and safety assessment of the spent fuel assembly and its transport cask. In view of the problem of how to reasonably simplify the finite element model, a more reasonable and accurate multistage simplified model is proposed for the spent fuel assemblies packed densely in the transport cask, which needs to be analyzed synchronously when dropping. First, the “key” spent fuel assembly is retained, and the “unimportant” assembly is simplified as a cylindrical entity. Based on this, the structure will continue to be simplified and a 1/4 near-earth model containing all characteristics will be established. Then, the LS-DYNA software is used for explicit dynamic analysis of vertical drop conditions. It is concluded that the failure risk of the spacers is the greatest. Therefore, the purpose of this paper is to propose a multistage simplified method for spent fuel assembly and its transport cask, which can provide a reference for the structural integrity analysis of the spent fuel assembly transport drop conditions.
Stiffness Analysis of High Contact Ratio Spur Gear with Asymmetric Teeth
Authors: Liang Xiao , Tang Xin , Li Yingjun , Shen Rui , Li Fajia , Wu Ziheng 
Published: August 2023

Abstract
The demands of high carrying capacity and low vibration of gear transmission systems in aviation, aerospace, and other areas are addressed by high contact ratio gears with asymmetric teeth, which have a wide range of potential applications. The Weber energy technique is utilized to determine the stiffness of high contact ratio spur gears with asymmetric teeth, and the effect law of the stiffness parameters is researched, due to the paucity of study on these gears. The influence of the drive side addendum factor, modulus, and pressure angle on the stiffness of asymmetric high contact ratio spur gears is investigated. The deformation of the gear will be exacerbated by an increase in the addendum factor, and the comprehensive stiffness of the gear will grow as more gear pairs participate in the meshing. The rigidity of gears may be greatly increased without ignoring modulus if the driving side pressure angle is properly increased.
Precision Variable-rate Control System for Mini-UAV-based Pesticide Application
Authors: Zhang Zhihong , Yuan Shuo , Lai Qinghui , Zeng Ronghao , Zhang Jingkun , Shen Siyu 
Published: August 2023

Abstract
Mechanized and efficient pesticide application is an effective measure to prevent crop diseases, control pests, and ensure stable yield. For crops in greenhouses, due to the complex operating environment, the traditional mechanical spraying method will lead to excessive pesticide spraying and pesticide residues. Based on the ultrasonic sensor array, a small crop canopy volume calculation model is proposed, and the Pulse Width Modulation (PWM) control model of nozzle flow is established. The compensation time of opening and closing delay of the nozzle was determined to be 0.201 s by the high-speed photography method. The optimal operating speed was determined to be 0.3 m·s−1 through the benchmark test. Then, the precision variable spraying control method was integrated to develop the precision variable plant protection UAV based on an ultrasonic sensor array. The test results showed that the droplet deposition density was greater than 20 drop s·cm−2, and the droplet coverage rate of precision variable spraying was less than 30%. In the experimental area, the pesticide dosage of conventional and precision variable spraying was 0.24 L and 0.15 L, respectively, The precision variable-rate spraying saved pesticide usage by 34.5%. The system can realize precise variable spraying according to crop location and crop canopy volume changes. This study will promote the rapid development and application of precision spraying technology for small plant protection UAVs.
Vibration characteristics of the rotary table of large spin coater and its influencing factors
Authors: Ding Long , Zhang Xingang , Liu Qiuyu , Yan Ying , Zhou Ping 
Published: August 2023

Abstract
The rotary table vibration of the spin coater directly impacts the quality of the spin coating film. In view of the unclear vibration characteristics of the rotary table during operation, the rotary table vibration characteristics and its influencing factors considering the spindle system are studied. Based on the elastic contact theory and multi-body system theory, the rotary table vibration characteristics of the rotary table when the parts of the rotary table are flexible are analyzed by establishing the rotary table multi-rigid body and flexible coupling dynamics models, respectively. By comparing with the rotary table vibration measurement results, it is found that the flexible treatment of the load tray is more consistent with the actual vibration characteristics. The study further analyzes the effects of the unbalance of the rotary table, the rotary table speed, the coaxiality of the load tray and the spindle, and the perpendicularity of the load tray and the spindle on the vibration characteristics. The results show that the influence of the spin coater rotary table under the actual working conditions is from the highest to the lowest degree of influence on the unbalance of the load tray, the coaxiality of the load tray and the spindle, the perpendicularity of load tray and the spindle, and the rotational speed of the rotary table. This study provides a reliable theoretical and experimental basis for the vibration characteristics analysis and structural design of the spin coater rotary table.
Synthesis on cardioid crank rocker mechanism with approximate uniform motion
Authors: Han Haotong 
Published: August 2023

Abstract
The cardioid crank is a planetary mechanism that generates a cardioid line. It is a crank with varying length and speed that moves along the cardioid line. The cardioid crank is used to replace the crank of the crank rocker mechanism, and its rocker mechanism with approximate uniform motion is obtained. The kinematic analysis method of the cardioid crank rocker mechanism is studied in this paper. The calculating method for the limit position and oscillating angle and the time ratio of the guide bar are given. Finally, the approximate uniform motion conditions of the rocker are obtained. The synthesis method of the approximate uniform motion mechanism is put forward in accordance with the time ratio or rocker oscillate angle, the minimum length of the guide bar is calculated, and the influence of center distance on the kinematic performance of the mechanism is discussed.
Synthesis of cardioid crank rocker dwell mechanism
Authors: Du Zheng , Zhang Bowen , Han Jiguang 
Published: August 2023

Abstract
The cardioid crank rocker mechanism is a mechanism obtained by replacing the crank of a crank rocker mechanism with a cardioid crank. The cardioid crank is a planetary mechanism capable of generating cardioid curves. Using the cardioid crank as the driving crank of the crank rocker mechanism is equivalent to a crank with variable speed and length moving along the cardioid line, changing the motion characteristics of the rocker. The motion characteristics of the cardioid crank rocker mechanism are studied, and the limit position of the rocker and the calculation method of the intermittent interval is given. The influence of the planetary linkage length and center distance on the intermittent interval, and how to complete the mechanical design with known intermittent angle are discussed respectively, and a comprehensive analysis is made.
The compound control of a Stewart mechanism for automatic assembly via co-simulation
Authors: Liu Tong , Huang Haitao , Chen Dongdong 
Published: August 2023

Abstract
With the advantages of big bearing ability, strong stiffness, and high precision, the Stewart structure with six degrees of freedom (6-DOF) has found its way into the fields of military equipment, aeronautics, and astronautics. In this paper, a Stewart mechanism used for automatic docking is studied via the co-simulation approach. The low-speed performance with a heavy load is improved by the speed feedback compensation of parallel cylinders. Firstly, after trajectory planning, the compound control strategy with Coulomb-Viscous friction-based speed compensation is proposed. Subsequently, the co-simulation framework, including the structure model in LMS. Motion, the hydraulic model in AMEsim, and the control model in Matlab/Simulink are separately established with corresponding parameters. Finally, the compound control strategy is comparatively studied with displacement feedback alone. The control errors of cylinder displacement would decrease from ±1.0 mm to ±0.4 mm, which obviously improves the control performance.
Structural Optimization of the Lower Door of the Main Landing Gear of an Aircraft
Authors: Yang Guiqiang , He Ping , Wang Yi , Liu Chaoni 
Published: August 2023

Abstract
In this paper, the topology optimization algorithm is used to optimize the main structure of the main landing gear lower door of an aircraft by combining the structural strength, structural stiffness, and processing technology [1-2]. Considering the balance of structural weight, structural strength, and material distribution, the structural topology optimization design result with reasonable structure, good manufacturability, and moderate weight is finally obtained.
A Numerical Study of Complex Impact Loads on Thin-Walled Casing of Aeroengine Considering Turbine Guide Vane Structure1
Authors: Zhong Wenyuan , Li Jiaqi , Yang Zhongyu , Feng Yinli , Sun Tao 
Published: August 2023

Abstract
As the main load-bearing component of the aero-engine system, the thin-walled casings have the characteristics of large size, complex structure, thin wall, and large area. In addition to the harsh working environment, it is necessary to study applicable preventive measures to contain high-energy fragments to ensure flight safety. The complex load formed by the axial impact and circumferential torsion exerted by the turbine rotor on the exhaust casing is studied, and the model includes the turbine rotor. By analyzing the deformation and energy dissipation of the exhaust casing in the calculation results, the dynamic response of the power turbine and the exhaust casing in the complex impact load is obtained, and it is verified that the initial speed of the power turbine has no obvious relationship with the dynamic response and energy dissipation of the exhaust casing. At the same time, it is concluded that the axial velocity and aerodynamic force of the power turbine have a strong positive correlation with the complex impact load and dynamic response of the exhaust casing. In the follow-up studies and equivalent experiments, these conclusions can be used as a reference for further experimental design.
The Interfacial Thermal Resistance Properties Of GNPs/Epoxy Thermally Conductive Composites By Molecular Dynamics Simulation
Authors: Du Gang , Yang Jie , Chen Lu , Ji Wangwei , Li Guangmao , Wang Yong 
Published: August 2023

Abstract
With the increasing power density and integration degree of electrical equipment, the problem of excess heat production is serious. Existing data show that the thermal management capability of electrical equipment is a key factor affecting the performance of electrical equipment. Therefore, the development of high thermal conductivity composites is an effective solution to improve the thermal management ability of equipment and extend the working life of equipment. With the purpose of enhancing the heat conduction of epoxy resin, graphene sheets (GNPs) with high thermal conductivity were added. Based on the reverse nonequilibrium molecular dynamics simulation (RNEMD) method, the thermal conductivity simulation of epoxy resin equipped with GNPs was carried out. The simulation results showed that the heat conductivity of epoxy resin equipped with GNPs had been greatly improved.
Investigation on the tribological property of marine engine bearing
Authors: Du Fengming , Zeng Yunbo , Yan Shaolong 
Published: August 2023

Abstract
The marine engine is one of the core devices of the ship. With the continuous progress of science and technology, marine engines are developing towards high power density, and the related tribological problems are more prominent. As one of the most typical friction pairs of marine engines, the crankshaft-bearing bush bears more and more loads and presents a trend of increased wear. By studying the wear behavior of the bearing bush, it is possible to deeply grasp the bearing wear mechanism, speed up the research and development process of the bearing bush, and further improve the wear resistance. In this paper, for the crankshaft-bearing bush pairing pair, a component-level bearing bush friction and wear testing machine is built, and the corresponding test method is established. The binary electroplating bush and an alloy shaft pair are selected for the experiment, and the wear law of the bearing bush is explored.
Effects of Temperature on the parameters of the Electrochemical Impedance Spectroscopy for Lithium-Ion Batteries
Authors: Ma Jinyu , Wang Hongwei , Zheng Chun , Tao Ziqiang , Fu Yanling , Bai Hong , Xiao Haiqing 
Published: August 2023

AbstractThe health status of lithium-ion batteries and the acquisition of internal information for battery designs and health predictions are of great significance. Electrochemical impedance spectroscopy (EIS) is a measurement method that has received more and more attention in the research on lithium-ion batteries’ performance. In this paper, three kinds of lithium-ion batteries made of different materials were studied to measure the impedance at different temperatures. An equivalent circuit model (ECM) was established, and the effect of temperature on the impedance of different batteries during the data was studied. Temperature is considered an important parameter for predicting batteries’ states. The result shows that the batteries’ impedances at -40°C are hundreds of times higher than those at 75°C. The diffusion impedance and battery transfer impedance of the three batteries all increase with the decrease in temperature, but NMC and LTO batteries have a higher tolerance to high temperatures than LFP. It is concluded that EIS combined with temperature is significant to batteries’ state estimation and performance evaluation.
Temperature Field Analysis of Oil-Cooled Heat Dissipation in High-Speed Permanent Magnet Synchronous Motor
Authors: Yang Cunxiang , Zhang Kai , Qiu Hongbo 
Published: August 2023

Abstract
With the development of high-speed permanent magnet synchronous motors (PMSM), the requirements for speed are getting higher and higher, and the power density increase is getting bigger and bigger. However, too high a loss density will cause motor heat dissipation difficulties, resulting in motor insulation aging and permanent synchronous magnet demagnetization failure, which seriously affects the safe operation of the motor. Therefore, it is necessary to analyze the fluid field and temperature field for oil-cooled high-speed PMSM. In this paper, a 40 kW back-wound oil-cooled high-speed PMSM is used as the research object. Firstly, a three-dimensional fluid-solid coupled heat transfer model of high-speed PMSM is established based on the parameters of the motor, and the fluid flow characteristics inside the motor are analyzed based on fluid dynamics and heat transfer theory, and then the overall and local temperature rise distributions of the motor are compared and analyzed to reveal the influence of the temperature rise of each component inside the high-speed permanent magnet synchronous motor after being cooled by the cooling structure. Secondly, based on the finite element model, the motor temperature rises and oil flow characteristics with oil flow rate are analyzed to come up with an optimized solution. Finally, the accuracy of the analysis method is verified by conducting temperature rise experiments on the prototype.
Test Analysis of 220 kV Rotating Transmission Angle Tower
Authors: Sun Zhicheng , Zhang Aoyu , Li Xiaotong , Xue Yuan 
Published: August 2023

Abstract
As the requirements for the protection of environmental water in the construction of transmission lines have increased, the position of the tower in steep mountainous areas often fails to meet the requirements because of the difference in tower legs, which causes damage to the original landform, thus resulting in the change of the path and the increase of the project investment. In this paper, we optimize the design of a rotating steel tower to adapt to the steep terrain of mountainous areas and reduce the base surface opening. The feasibility of the proposed rotating tower optimization design is demonstrated by analyzing the real test data of the rotating tower.
A statistical characterization model of the microscale contact state of polishing pads
Authors: Shi Haosong , Di Hongyu , Zhou Ping , Guo Dongming 
Published: August 2023

Abstract
Chemical mechanical polishing (CMP) greatly benefits from the wafer and pad’s microscale contact condition. With so many varying pressures and wafer layouts, it is incredibly difficult to measure all the microscale contact states. Therefore, there is an urgent need to realistically characterize the morphology and contact state of polishing pads. A statistical characterization model of the microscale contact state of polishing pads was developed in this investigation. The microscale contact states under different pressures were measured to make sure that the model was accurate. This proposed model can extract the pad morphology parameters from the microscale contact state to predict the pad surface morphology and, thus, the microscale contact state in arbitrary conditions. This study can provide some recommendations for stability in CMP and the production and use of pads.