bluuebunny/crossref_metadata_2025_split huggingface dataset:
A study of distributed power access capacity taking into account distribution network state analysis
Authors: Shi Bingbiao , Chen Zhigao 
Published: February 2025

Abstract
Distributed photovoltaic power generation has become the key development direction of new energy in the future, but a large number of distributed photovoltaic power sources connected to the power grid will have a significant impact on power quality and grid state. In response to the above-mentioned issues, a method of accessing the capacity of distributed power supply, taking into account the grid state analysis, is proposed to improve the system voltage and stabilize it, and to reduce the network loss of the distribution network. The impact of distributed photovoltaic power generation with different access capacities on the network loss and voltage of the chain distribution network is investigated by calculating the system currently using the forward-back generation method, and then the calculation and simulation analysis are performed based on MATLAB, and the simulation results show that a certain capacity of distributed PV power can effectively improve the system voltage and stabilize it near the rated voltage, which has a significant effect on the loss reduction of the system, and improves the operation status of the distribution network.
Enhancing power quality in distribution networks with self-adaptive VPI-controlled grid-forming battery energy storage system
Authors: Yan Zijie , Xiong Liangli , You Li , Han Gang , Li Xiangjun 
Published: February 2025

Abstract
The development of distribution networks is facing new challenges due to the increasing penetration of distributed energy resources and electric vehicles. Power quality issues, such as voltage imbalance and harmonic distortion, are significant barriers to the efficient operation of distribution networks. This paper presents an approach to enhance power quality in distribution networks by employing self-adaptive Vector Proportion Integrators (VPI) controlled Grid-Forming Battery Energy Storage System (GFM-BESS). The control strategy and capability of a low-voltage ride through (LVRT) have been validated through simulation in MATLAB/Simulink.
Experimental investigation of saturated pool boiling on a porous copper-graphene coating surface with microgrooves
Authors: Fei Guochao , Du Yanping 
Published: February 2025

Abstract
In this study, a microgroove porous copper-graphene composite coating was fabricated on a copper substrate utilizing a combination of salt template sintering and mechanical cutting. The pool boiling heat transfer performance of the modified surface was investigated using water as the working fluid at atmospheric pressure. The experimental results demonstrated that the integration of microgrooves with a porous copper-graphene coating substantially improved the pool boiling heat transfer performance. Among the tested configurations with 4, 6, 10, 18, and 24 microgrooves, the surface with 18 grooves exhibited the most superior performance, marked by an 82% reduction in the onset of nucleate boiling (ONB), a 189% increase in the critical heat flux (CHF), and a 140% enhancement in the heat transfer coefficient (HTC) compared to a smooth copper surface. Further analysis of bubble dynamics revealed that the microgroove porous copper-graphene coating promotes heat transfer by creating a gas-liquid separation structure at low heat flux and by extending the triple-phase contact line at higher heat flux, both of which contribute synergistically to the enhanced boiling performance.
Uniformity analysis of flow distribution in U-shaped parallel flow structure
Authors: Li Qiangqiang , Xu Yan , Sun Xiaoxia , Gu Cao , Cao Yuanfu , Zhao Xinyu 
Published: February 2025

Abstract
The U-shaped parallel structure is commonly seen in heat transfer components and cooling systems. Due to the asymmetry of the geometric structure and the nonlinear effects of turbulence, the flow distribution among individual branches tends to be uneven. This paper conducts numerical simulations specifically for the water side of a plate-fin heat exchanger and an 8-branch parallel cooling structure, investigating the influence of the ratio α between the outlet and inlet cross-sectional areas on the uniformity of flow distribution. Furthermore, a theoretical analytical model is derived. The results indicate that as α increases from 1 to 1.4, the uniformity of flow distribution gradually improves. However, when α continues to increase, the flow near the inlet decreases while the flow at a further distance increases. The analytical model suggests an optimal α value of 1.23, which is close to the findings from the numerical model. These research findings hold significant application value for practical engineering design and scientific research.
Experimental study on serial and parallel operation of fans based on flexible duct
Authors: Dong Hongshan , Jiang Jianzhong 
Published: February 2025

Abstract
Based on the flexible duct, tests of serial and parallel operation of fans have been conducted. The experimental schemes of single fans running at different frequencies and combined operation at different locations were designed. Considering the air leakage of the duct, the parameters such as pressure, velocity, terminal air volume and input power were tested, and the experimental results were compared with the theoretical calculation results. Results indicated that the fan speed was directly proportional to the frequency, and the total voltage was directly proportional to the square of the frequency when the single fan operated. In series operation, when the second fan was at 1/3 of the air duct, there was no negative pressure area in the duct, and a full positive pressure air supply was realized. The parallel operation of fans was suitable for the network with small impedance and large air demand. The power consumption per air volume of fans in parallel operation was higher than that in series operation. In a series operation, the energy consumption would increase when the distance between two fans was too close or too far. According to the experimental results, some references and suggestions were put forward for the serial and parallel arrangement of fans in practical design.
Analysis and optimization of electric field distribution of controllable oscillating high voltage DC circuit breaker
Authors: Li Jikai , Zhang Lei , Li Gaoshang , Yan Xin , He Qinglian 
Published: February 2025

Abstract
In recent years, domestic DC transmission projects have been rising. High-voltage DC circuit breakers, as key equipment in DC power grids, have also received more and more attention from various scientific research units. However, the current research on DC circuit breakers is still in the topological research stage. There is a lack of experience in the development of specific products. As a complex set of integrated equipment, high-voltage DC circuit breakers have many components and very complex potential distribution. To ensure the safe and reliable insulation structure of DC circuit breakers, not only sufficient air clearance between components with different potentials is required, but also sufficient assessment of their electric field distribution is required. This study intends to conduct simulation calculation research on the electric field distribution of DC circuit breakers and propose a reasonable electric field optimization scheme. In the electric field calculation, the paper adopts an analysis method combining the full model and the sub-model. Then, the components in the full model with excessive electric fields are optimized and checked locally through sub-model analysis. Reasonable electric field optimization measures are proposed through the analysis of the electric field distribution characteristics of the sub-model.
Study on the effect of thermal oxidation on the gas permeability and mechanical properties of PA6
Authors: Li Xinshu , Wang Qing , Bai Jingru , Li Tingqu 
Published: February 2025

Abstract
This study explores the gas permeability and mechanical properties of PA6 material subjected to thermal oxidation using an air-circulating oven. The PA6 samples were treated at 130°C for varying durations. Gas permeability was analyzed by using both the differential pressure and constant pressure methods. The results revealed that the PA6 sample oxidized at 130°C for 5 hours exhibited the best gas barrier properties, with the lowest gas permeability coefficient of 0.963×10−15 cm3·cm/cm2·s·Pa, representing a 62% reduction compared to the untreated PA6 sample. Although the gas permeability coefficient increased after 15 hours of thermal oxidation, it performed better than the untreated sample. The mechanical properties were assessed through tensile, bending, and impact tests. The findings showed an increase in both tensile and bending strength with prolonged oxidation, indicating that thermal oxidation at appropriate temperatures can enhance the hardness and strength of PA6. However, impact strength decreased, mirroring the reduction in elongation, indicating a decline in plastic deformation capacity and increased brittleness post-oxidation. These results provide new insights into the application of PA6 in Type IV hydrogen storage tank liners and have significant implications for hydrogen energy storage strategies.
Study on mechanical defects of open high voltage disconnecting switch
Authors: Yang Muqing , Mo Xiang , Mao Tongtong , Zhang Xingwang , Liu Zhi , Guo Mingyuan , Man Weizhen , Luo Rui , Cheng Shunli , Xiao Yilong 
Published: February 2025

Abstract
The open-type high-voltage isolating switch is usually exposed to various atmospheric environments, eroded by wind, sand, rain, snow, fog, etc. Its metal parts in the transmission mechanism are prone to oxidation corrosion, shaft pin, bearing, and connecting rod grease in direct contact with the air and are prone to deterioration and loss, resulting in defects such as Card astringent and card resistance, which will further lead to mechanical failures such as insufficient opening and closing, phase asynchronization, insulator breakage, loose contacts, and heating. At present, the limitation of the commonly used state judgment method of disconnecting switches is that it cannot provide information such as whether there is jamming and phase synchronization during the opening and closing process. This paper proposes a diagnostic method of mechanical defects of the isolating switch based on motor power monitoring and establishes the simulation model of the GW7 open isolating switch. By analyzing the characteristics of the power curve, it can identify the opening and closing states, and detect whether there are defects such as jamming, insufficient opening and closing, and phase asynchronization during the operation process.
Experimental study of an integrated thermal management system for electric vehicle under extreme conditions
Authors: Lin Changbo , Xu Enyong , Chen Mengjun , Lu Zengjun 
Published: February 2025

Abstract
The thermal management system significantly impacts mileage range, battery safety, and cabin comfort for electric vehicles. In this paper, to solve the heat dissipation problems involved with passenger cabins and power batteries at high temperatures, an integrated thermal management system was established by employing some critical components including a compressor, pump, chiller, and thermal control valves. The thermal performance of the integrated cooling system was experimentally investigated under the extreme ambient temperature of 40℃. The test results show that the cabin can be cooled down to 25℃ in about 30 minutes with a cooling capacity of 5.27 kW for independent cabin cooling mode. The battery temperature can be maintained at 36℃ for 30 minutes for independent battery cooling mode with a cooling capacity of 5.04 kW. For combined cabin and battery cooling mode, the cooling demand was achieved in 60 minutes with a cooling capacity of 10.3 kW. In addition, the coefficient of performance is 2.73, 2.25, and 1.97 for different cooling modes.
Degradation analysis of catalyst layer in PEMFCs under voltage cycling conditions
Authors: Zhang Fan , Yin Yan , Wang Bowen , Qin Zhikun , Yao Junqi , Guo Ting 
Published: February 2025

Abstract
The catalyst layer (CL) serves as the fundamental component of the proton exchange membrane fuel cells (PEMFCs), comprising a Pt-based electrocatalyst, carbon support, and ionomer. The CL is essential for facilitating electrochemical reactions and efficient mass transport. However, CL will undergo significant degradation after long-term operation, mainly induced by catalyst particle growth and mass loss. To analyze the degradation mechanisms of the Pt catalyst, a 1-D Pt degradation model for PEMFCs is developed, which can characterize the degradation phenomenon of the CL during long-term operation, including the mass loss of the Pt catalyst, the Pt catalyst particle size growth, and the precipitation of Pt ions in proton exchange membranes (PEM). The results indicate that during the voltage cycling, elevated voltage enhances the dissolution of the Pt catalyst, thereby accelerating both particle size augmentation and mass depletion of the catalyst. After 5000 accelerated durability tests, the overall performance of fuel cells significantly decreases, with ECSA dropping to around 60% and Pt catalyst particles growing by more than 20%. The established model lays the foundation for investigating the degradation process of Pt catalysts and optimizing the design of CL as well as operating conditions.
Study on the rarefied gas flow in micro-channel via DSMC method
Authors: Wu Yi , Li Kesheng , Zhang Zhijun , Han Feng , Liang Ruquan , Shi Jianhui , Zhang Dengbo , Song Yuanmei , Zhang Shiwei 
Published: February 2025

Abstract
A micro-channel with thermally induced flow as the mechanism is proposed. The micro-channel is composed of quadrangles with constant and different temperatures. The flow characteristics of gases within micro-channels are scrutinized by employing a Direct Simulation Monte Carlo (DSMC) approach. The effects of the temperature difference and periodic length on the gas pumping capacity are analyzed, respectively. The findings reveal that the velocity of gas flow escalates in conjunction with an augmented temperature gradient, thereby signifying an enhancement in the gas pumping efficacy of microchannels. The gas flow velocity becomes faster with the increase of the periodic length, which indicates that the gas pumping ability of the micro-channel also becomes stronger. The outcomes furnish a foundational theoretical framework that can underpin the engineering implementation of novel micro-gas sensors.
Current stress optimization control applied to three-level dual-active-half-bridge
Authors: Xu Chen , Zuo Dongsheng , Zhang Guodong 
Published: February 2025

Abstract
The Three-level Dual-Active-Half-Bridge (TL-DAHB) reduces the voltage withstand level but increases the current stress compared to the Dual-Active-Bridge (DAB). This paper designs a current stress optimization algorithm by Karush-Kuhn-Tucker (KKT) condition to solve the problem of higher current stress in TL-DAHB and proposes the optimal control of current stress by combining with Dual-Phase-Shift (DPS) control. Finally, the feasibility of current stress optimization control is verified by building a Simulink model.
Estimation of junction temperature of SiC MOSFET based on thermal impedance modelling
Authors: Zhang Yan 
Published: February 2025

Abstract
This paper proposes an enhanced methodology for estimating the junction temperature of silicon carbide metal-oxide-semiconductor field-effect transistors (SiC MOSFETs) based on the thermal impedance model. The transient thermal resistance curves are obtained through thermal simulation of the physical model of the module, and a fourth-order thermal impedance model is subsequently constructed. The model is constructed to fit the thermal impedance between the chip and the internal thermal resistor in the package, as well as to the coolant, which can be classified by different thermal time parameters and combined with the loss data in different categories. By classifying different thermal time parameters and combining the loss data under different working conditions, the junction temperature estimation under transient and steady state conditions can be achieved. In the validation section, the simulation data are calibrated and compensated by constructing a module outflow capability test bench and utilising an infrared camera to enhance the precision of the junction temperature estimation. This process also serves to reinforce the reliability of the proposed methodology.
Research on heat transfer and heat load analysis in a certain type of engine cylinder
Authors: Cui Chenyang , Kang Qi , Xiao Ning , Wang Lei , Hu Linxiang 
Published: February 2025

Abstract
This article takes a certain type of high-power engine as the research object, establishes a complete heat transfer simulation model using the three-dimensional to one-dimensional simulation method, and verifies the accuracy of the model with bench test data. Subsequently, an analysis was conducted on the heat transfer and temperature distribution of the engine under calibration conditions. The simulation results showed that the combustion medium transferred the most heat to the cylinder head and the least heat to the cylinder liner; the heat carried away by the coolant in the engine cylinder head is greater than that in the cylinder block; the temperature of the cylinder is generally lower than that of the cylinder block, and the coolant temperature of the cylinder block is generally lower than that of the cooling water chamber of the cylinder block; the heat load of the third cylinder is the most severe, with the highest temperature of its cylinder head being 513.7 K and the lowest temperature being 447.1 K; the highest temperature of the cylinder liner is 572.5 K, and the lowest temperature is 423.4 K; the maximum temperature of the intake and exhaust valves is 607.1 K and 700.4 K, respectively, and the minimum temperature is 363.2 K and 377.6 K, respectively.
Inversion of the light curves of space debris using simulated satellite-based observations
Authors: Galeano David , Peltoniemi Jouni , Enríquez-Caldera Rogerio , Guichard José 
Published: February 2025

Abstract
The growth of space debris population smaller than 10 cm in Earth orbit is alarming for the safety of active missions. Observation campaigns fail to target objects of this size, as they are undetectable with optical or radar instruments from ground-based observations. For this reason, modern satellite-based detection strategies are proposed. Implementing simulations and virtual instruments is crucial to evaluate the performance of detection systems equipped on active satellites. Recently, the FGI (Finland), the CSEM (Switzerland) and the ESA/ESTEC (the Netherlands) presented the Coincidental Orbiting Laser Sheet Particle Monitor (COLA). COLA is a simulation developed to exploit the potential of laser sheets and fast detectors to track particles in the mm-cm size range with a population modelled by the software MASTER (developed by ESA). The simulation provides also photometric data, strengthening the developed detection model; an advantage of photometric data is that they allow the use of methods such as light curve inversion, which was initially developed to model asteroids with the LCInvert software. INAOE (Mexico) implemented light curve inversion software similar to the LCInvert and successfully applied it to actual and simulated data. We present the code implementation for curve inversion developed on objects detected by the COLA system. We extend the satellite system from one satellite of a dual laser sheet to a swarm of six satellites. The first main satellite has the laser sheet and a secondary beam that is triggered on by the first detected photon by the sheets. Five passive observers with wide angle cameras measure the target from multiple directions as it passes through the field of view. The observations thus produce a light curve that allowed us to recover the shape and orientation state with the inversion method. We constructed synthetic light curves using random trajectory test particles representing flakes, grains, and needles. The results reached a minimum relative error of 12.38 % for the grain in the inclination of the pole. The azimuth of the pole presented a minimum error of 5.61 % for the flake. Finally, the difference between the simulated curves and the curves obtained after performing the inversion presents a squared error of 5.29×10−2, 2.77×10−2 and 2.38×10−2 for the grain, flake and needle, respectively. In future work, we will seek to optimize the configuration of the satellite swarm and implement a light curve inversion method that considers light scattering from human-made objects.
A Hybrid Fuzzy-PID Approach for Self-Balancing in Attitude Determination and Control Systems testbeds
Authors: de Jesús Pablo-Sotelo Abraham , Luviano-Juárez Alberto , Hernández J. 
Published: February 2025

Abstract
In recent years, CubeSat-type satellites have experienced tremendous growth, becoming one of the alternative paths for space technological development for multiple space agencies around the world. Within the design process of CubeSat satellites, the evaluation of the multiple subsystems is mandatory. Among the satellite’s vital subsystems is the Attitude Determination and Control System (ADCS), whose ground validation is crucial for the satellite’s mission. This subsystem is typically tested on ground using air-suspended test benches, which face a very specific problem related to the initial test conditions due to the low-friction environment that complicates the test’s execution. This article develops a Fuzzy-PID controller with a Mamdani-type inference system capable of resolving stability problems in one degree of freedom, based on a simplified model of traditional ADCS test benches.
FPGA-based implementation of a delta modulation technique for aerospace communications transmission chain
Authors: Ramírez-López F. , Casillas-Aviña G. E. , Yáñez-Casas G. A. , Hernández-Gómez J. J. , de-la-Rosa-Rábago R. 
Published: February 2025

Abstract
Satellite communications, driven by increasing complexity and demand, require innovative solutions for both physical and logical system layers. This work focuses on optimizing delta modulation within a reconfigurable electronic architecture to enhance hardware performance in satellite applications. Delta modulation, a widely used sampling and quantization technique in wireless applications, is examined in the context of analog-to-digital conversion, a critical stage in satellite telemetry transmission. Implementing this technique in a reconfigurable architecture offers several advantages: optimization of power consumption, facilitating integration into more compact systems and reducing the energy impact on satellites; miniaturization, enabling the creation of smaller, more efficient devices; flexibility, adapting to various operational requirements and improving system versatility; and improved transmission quality, providing more reliable and effective communication. This study highlights delta modulation’s potential to optimize hardware and efficiency in satellite communications applications.