bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal runaway difference between fresh and retired lithium iron phosphate batteries under overheating
Authors: Wang Cong-jie , Wang Shu-ping , Gao Fei , Li Chang-hao , Zhu Yan-li 
Published: May 2023

Abstract
Safety is an important factor restricting the cascade utilization of lithium-ion batteries (LIBs). In this paper, the safety characteristics of fresh and retired lithium iron phosphate batteries are investigated by means of a heating-triggered thermal runaway (TR). The results show that under the heating condition of 200 W, the internal short circuit (ISC) can directly cause the TR of a new battery and lead to an explosion with an overpressure of 98.9 kPa. However, there is still a buffer time of 13.1-22.3 min between the ISC and TR for the retired battery with states of health (SOHs) of 80% - 60%, and the retired battery cannot explode. The large-scale ISC onset time, TR onset time, and TR onset temperature of the 70% SOH battery are 27.4 min, 40.5 min, and 179.9 °C, respectively, which are the smallest among retired batteries, indicating that the 70% SOH battery may be more likely to trigger TR. The findings can provide guidance for the safe application of retired batteries.
Study on Dynamic Line Rating of Overhead Transmission Line Based on Large-Scale New Energy Power Grid Connection
Authors: Peng Zhengwei , Shi Jinzhi , Li Yanyan , Huang Junhan , Zhao Jinquan 
Published: May 2023

Abstract
With increasing new energy power grid connections and increasingly complex user loads, higher ampacity is required during peak power demand. Construction of new transmission lines can cost a lot and is limited by the environment and the shortage of land resources. Considering the intermittency of new energy power generation, dynamic line rating can increase the power transmission capacity of existing lines by exploiting their potential capacity. In this paper, the ampacity of transmission lines is calculated accurately, and influencing factors of ampacity are studied. Additionally, temperature change patterns and field distribution of the lines are studied. The results show that wind speed, ambient temperature, and sunshine intensity are the three main factors affecting the ampacity. Wind speed is proportional to ampacity, while ambient temperature and sunshine intensity are opposite. Then, it is found that the thermal inertia effect of transmission lines that temperature change lags behind current change can be utilized for ampacity enhancement. Furthermore, the radial temperature difference is found in the lines, and excessive temperature differences may accompany the risk of strand breakage. It is of great significance to study the temperature field of the lines for dynamic line rating based on large-scale new energy power grid connections.
Effect of TiO2-SiO2 composite films on the performance of perovskite solar cells
Authors: Wang Renbao 
Published: May 2023

Abstract
Nano-TiO2 semiconductor film has the characteristics of high porosity and large specific surface area. However, there is much surface state in the TiO2 semiconductor film, and its energy level is in the band gap, which forms a local state with traps, restricts the movement of electrons in the film, and causes serious electron recombination. In this paper, the TiO2 surface is covered with a wide band gap semiconductor SiO2 in the electron transport layer of the perovskite solar cell. A core-shell electrode is formed to inhibit electron recombination and improve efficiency of perovskite solar cells.
Research on Calculation Method of Energy Storage Capacity Configuration for Primary Frequency Control of Photovoltaic Power Station
Authors: Zhang Ning-yu , Zhu Xin-yao , Liu Jian 
Published: May 2023

Abstract
An energy storage capacity allocation method is proposed to support primary frequency control of photovoltaic power station, which is difficult to achieve safe and stable operation after a high proportion of photovoltaic connected to public power grid. In this paper, by taking the photovoltaic power plant containing energy storage as an example, and based on the fluctuation characteristics of photovoltaic power output and the performance requirements of primary frequency control response, the required battery storage capacity of photovoltaic power station for primary frequency control is calculated without considering the power abandonment and power limitation conditions, and the typical case is established based on power system simulation software to verify the reasonableness and effectiveness.
Analysis of Intergranular Corrosion Cracking of Austenitic Stainless Steel Tubes for Utility Boilers
Authors: Sun Yunfei , Tan Xiaomeng , Liu Jun , Yun Feng 
Published: May 2023

Abstract
The cracking failure accidents of austenitic stainless steel pipes of utility boilers often occur. The intergranular corrosion cracking caused by improper control of welding, heat treatment and cold working processes is an important reason for its failure. Through the analysis of typical cases, this paper expounds on the influence of welding, heat treatment and cold working processes on the service safety of austenitic stainless steel pipes and puts forward protective measures.
Optimal Scheduling of Pumped Storage Power Station Based on Immune Ant Colony Algorithm
Authors: Chen Xin , Xiao Renjun , Ma Jiankai 
Published: May 2023

Abstract
At present, in the application of hydropower for multi-energy complementary, the utilization of large hydropower stations and pumped storage power stations is mainly considered. The utilization of small hydropower stations is relatively scarce. The use of small hydropower can implement complementary regulation of distributed energy nearby, which is very conducive to distributed power consumption. This paper proposes an improved genetic immune ant colony optimization algorithm to find the optimal solution. To solve the shortcomings of the ant colony algorithm in the early stage, such as the weak ability to traverse all paths, easy falling into a premature and local optimum, and slow convergence speed, a genetic algorithm is applied to initialize the genetic factor. It can dynamically adjust the step factor and introduce the genetic immune ant colony with a momentum coefficient when updating the position to search for the optimal solution. The penalty function is adopted to solve the model, and the specific steps are given. Through the comparative test of the algorithm, it is verified that the algorithm proposed has a better effect on the optimal solution, the shortest occupied time, good reliability, and strong optimization ability. It is of great practical significance to the scientific evaluation of the water resource’s eco-economic system.
An Efficiency Optimization Strategy for Electric Vehicle Wireless Energy Transmission System
Authors: Wang Runhua , Shi Yuefeng , Wang Jihui , Wang Yawei 
Published: May 2023

Abstract
Magnetic coupling resonant wireless energy transmission technology has become an important research direction for electric vehicle wireless charging systems. This paper proposes an efficiency optimization strategy for the electric vehicle wireless energy transmission system based on LCL-S topology to improve the efficiency of electric vehicle magnetic coupling resonant wireless charging. This paper analyzes the optimization method of system efficiency based on LCL-S topology, establishes an experimental model in MATLAB/Simulink simulation software, and verifies it with the control variable method. The experiment shows that the efficiency optimization strategy based on the LCL-S topology proposed in this paper can effectively improve the system transmission efficiency and stabilize the transmission efficiency at a higher level faster.
Study of Temperature Rise Characteristics and Voltammetry Characteristics of ZnO Varistor under 10/350μs Pulse Current
Authors: Xiong Fuzhi 
Published: May 2023

Abstract
To study the effect of 10/350μs pulse current on the electrical performance of ZnO varistor, a high-current impulse experimental study was conducted in this paper. Firstly, the varistor was subjected to different amplitude impulse discharge experiments, and the temperature change of the varistor after the impulse was recorded. Then, the temperature of the varistor at the moment of 1 second after the pulse impulse was suffered by the Asymptotic function, and the Levenberg-Marquardt optimization algorithm was calculated to compare the temperature rise of the varistor under different current amplitudes. Finally, the upward shift of voltammetry characteristics in the high-current region after the impulse was explained according to the double Schottky barrier model and the linear chain aging theory. The results show that the higher the pulse current amplitude is, the higher the temperature rise of the varistor is at the 1s moment. The highest voltammetry characteristic upshift is caused by the 6.4kA pulse current. The temperature rise and the voltammetry characteristic drift in the high-current region are positively correlated. The results of the study can provide a reference for manufacturers to produce ZnO varistors for direct lightning protection of buildings.
Research on fault causes and treatment methods of squirrel-cage asynchronous wind turbine
Authors: Zhang Xiuqi , Gao Huifang , Cao Bin 
Published: May 2023

AbstractRenewable energy development is conducive to alleviating the climate problem, and it is an important measure to fulfill China’s double-carbon commitment. This paper first introduces the current situation of wind power generation and the working principle of a squirrel-cage asynchronous wind turbine, then counts the fault data of squirrel-cage asynchronous wind turbine, sorts out its common faults, and deeply analyzes the causes of the faults. Finally, it puts forward corresponding treatment methods for different kinds of faults, as well as suggestions for further improving the reliability of the squirrel-cage asynchronous wind turbine.
Modelling of Large-Scale Photovoltaic Power Generation System Based on PSCAD and Analysis of Its Stability
Authors: Chen Xiaoke , Li Yanyan , Shi Jinzhi , Zhao Jinquan , Huang Junhan 
Published: May 2023

Abstract
In this paper, based on the study of PV power generation principles and mathematical models of PV cells, PSCAD simulation modelling is performed for a large-scale PV plant with required output over 100 MW, and its operational characteristics are analysed. An improved Newton iteration, conductance increment method and semi-aggregate equivalent control algorithm are used to achieve maximum power point tracking (MPPT) for large-sized photovoltaic electricity plant. Finally, the simulation analysis of the large-scale photovoltaic electricity generation system under normal operation and light disturbance is conducted to validate the validity and stability of the model.
Skeleton-Based Human Activity Recognition of Low-voltage Distribution Room Based on MQTT Protocol and Wireless Sensor Network
Authors: Chen Deying , Chen Jing , Tong Yixuan , Zheng Shaocong 
Published: May 2023

Abstract
For the activity recognition of operators in low-voltage distribution rooms, a human activity recognition system based on the bidirectional gated recurrent unit model (BiGRU) is proposed to realize the skeleton information acquisition by the WiFi Channel State Information (CSI) sensor. The CSI sensor is used to collect the activity data and the Kinect v2 camera is used to capture the skeleton of the human body as annotations of the CSI data. The BiGRU model is employed to effectively extract the characteristics of the data. Aiming at the problem of poor remote communication, the MQTT connection can be established by using Message Queuing Telemetry Transport (MQTT) protocol combined with ESP8266 WiFi serial port communication module is proposed to improve the poor communication situation and carry out better data communication. The system achieves remote intelligent monitoring of the activities of the operator in the low-voltage distribution room.
Research on Processing the Feature Model of Converter Station Based on Machine Learning
Authors: Zhu Liu , Wang Kang , Sun Fei , Wang Weijia 
Published: May 2023

Abstract
The current traditional converter station feature model processing method uses switching functions to model converter station equipment, which leads to poor processing results because it ignores the dynamic coupling characteristics between the second harmonics inside the converter station. In this regard, a machine-learning-based switching station feature model processing method is proposed. By combining different terminals to determine their port parameters, constructing the characteristic impedance model of the converter station, using time-domain recursive convolution to calculate the voltage levels at each key point of the AC system, and finally calculating the magnitude as well as the phase angle constants, the time-varying model of the multi-harmonic converter can be fixed. In the experiments, the computational accuracy of the proposed method is verified. The analysis of the experimental results shows that the proposed method has a high component amplitude and excellent computational performance when the characteristic model of the converter station is processed.
Numerical Simulation Study on the Influence of Yaw-to-Wind Angular Velocity on Wind Turbine Aerodynamic Characteristics
Authors: Jin Baoyu , Gao Zhiying 
Published: May 2023

Abstract
In this paper, the wind turbine of NREL 5MW wind turbine is used as the research object, and the wind turbine is simulated from yaw-to-wind angle 30°-0° at different yaw angular velocities (0.5°/s, 1°/s, 2°/s) under rated operating conditions by using the slip grid model in fluent solver and custom UDF function program. The output characteristics and aerodynamic characteristics of the wind turbine under dynamic wind conditions are studied, and the effects of yaw angular velocity and yaw-to-wind angle on the output power, and near wake speed of the wind turbine are analyzed. The results show that the smaller the yaw angular velocity of the wind turbine is, the better the output power of the wind turbine can be obtained when the yaw angular velocity is 0.5 °/s 1 °/s 2 °/s. By analyzing the wake velocity, it is found that the smaller the yaw angular velocity is, the greater the larger the wake velocity loss area is.
Analysis and Research on Windproof Deviation of Coastal 500kV Transmission Line Jumpers
Authors: Wu Xiaojie , Fan Guiyou , Fu Zhiwei , Chen Xingbao , Lin Chaohui , Huang Guomin , Shen Xiaoyang , Lin Yuanguo , Zhang Luzhou , Xie Yangbin 
Published: May 2023

Abstract
Based on the current situation of frequent wind deflection faults of 500 kV transmission line jumpers caused by typhoons in coastal areas, this paper proposes a new sectional wind deflection proof post insulator transformation measure by analyzing the advantages and disadvantages of conventional jumper wind deflection transformation measures, which effectively improves the anti typhoon and wind resistance of 500 kV transmission line jumpers. It can save the amount of steel for tower transformation and greatly shorten the transformation outage time. It provides a solution for future coastal transmission line construction and wind deflection prevention reconstruction.
Research on Supraharmonics Suppression Strategy of Distribution Network based on Dynamic Cooperative Control of Multiple Harmonic Sources
Authors: Liu Shaojie , Zhao Yingying , Tian Yue , Fan Yubo , Ye Jifang 
Published: May 2023

Abstract
In view of the increasing number of supraharmonic sources in distribution network and the increasing distortion of power grid waveform, a strategy of supraharmonic suppression in distribution network based on dynamic coordinated control of multi-harmonic sources is proposed. The characteristic harmonic current components related to carrier frequency in the output current of each supraharmonic source are shifted by several angles through carrier phase shifting, so that the total current harmonics of all supraharmonic sources merged into point of common coupling (PCC) are obviously reduced to meet the requirements of PCC supraharmonic control. This strategy dynamically adjusts the phase-shift angle according to the running number of supraharmonic sources to avoid the problem that the harmonics of the remaining supraharmonic sources cannot be cancelled after some supraharmonic sources exit the system. The simulation results show that the supraharmonic suppression strategy based on dynamic cooperative control of multi-harmonic sources in distribution network can significantly suppress the supraharmonic current component and voltage distortion rate of a certain number of parallel points.
The online monitoring method of single-phase grounding fault in medium voltage distribution network based on multi-measuring point information
Authors: Zhang Daolu , Wu Dan , Lin Junhong , Huang Fu 
Published: May 2023

Abstract
To reduce the error of single-phase ground fault and improve the security and stability of distribution network operation, an online monitoring method for single-phase ground fault in a medium voltage distribution network based on multi-measuring point information is proposed. Based on the analysis of single-phase grounding transient characteristics, the fault location is determined from the information of multiple measuring points according to the characteristics analysis results to realize the fault subsection location, identify the fault line section, and improve the location accuracy. Based on the fault location results, fault monitoring is realized through the “four-in-one” intelligent distribution terminal. The experimental results show that the accuracy of the monitoring results of this method is kept above 95%, and the monitoring error value of grounding fault is kept at about 1%, so the monitoring results have high reliability.
Distribution Network Line Loss Calculation Method Considering Distributed Photovoltaic Access
Authors: Zhang Lei , Jing Shuzhi , Wang Yang , Tian Yuntao , Cheng Jin , Liu Xiaobin 
Published: May 2023

Abstract
With access to a high proportion of distributed photovoltaics, the power quality and line loss of distribution networks have become the focus of power grid enterprises. Traditional line loss management does not consider the impact of distributed photovoltaic access, which leads to incomplete line loss calculation methods and management means of distribution network. Therefore, this paper establishes a simulation analysis model of high proportion distributed generation connected to the distribution network and puts forward the overall loss method of the distribution network through theoretical analysis. On this basis, the IEEE 34-node system is used to calculate the impact of different capacities and locations of distributed access on the voltage distribution and line loss of the entire distribution network. The example shows that there is a corresponding relationship between the access capacity of DG and the lowest network loss. When the access capacity of distributed generation is too large, the system’s network loss will increase. Therefore, it is necessary to reasonably select the access capacity of distributed generation. The method proposed in this paper is accurate, and can also take the actual limitations of existing photovoltaic access and developable photovoltaic capacity into account, so it has strong engineering practicability.
Investigation of the Design Conformity of Civil Aircraft Battery System to Airworthiness Items
Authors: Wu Shanyong 
Published: May 2023

Abstract
Due to its material, function, safety, and other characteristics, there are also special requirements in terms of the design and verification of civil aircraft batteries. This paper studies the airworthiness compliance design method of the civil aircraft battery system. First, it introduces the battery technology used in mainstream civil aircraft, obtains specific design requirements by analyzing the airworthiness clauses applicable to battery systems, and then proposes the key issues that need to be considered in the design process of civil aircraft battery systems based on these design requirements. That is to say, the design of a civil aircraft battery system must fully consider the requirements of function, performance, and installation, which are defined in airworthiness regulations, and then it can be used safely on a civil airplane.
Study on the combustion process of the ramjet combustion chamber
Authors: Zhang Tingliang , Zhao Hui , He Lantao , Wang Tianyu 
Published: May 2023

Abstract
To explore the ignition performance of the ramjet combustion chamber, this paper combined the specific structure and working principle of the ramjet to model the ramjet combustion chamber, and carried out numerical simulation research on the flow field characteristics and combustion process of the stable operation of the combustion chamber. The results show that for the blunt-body of the flame stabilizer, the overall flame stability zone is relatively large at low inlet velocity, but the strength of the return zone at low inlet velocity is smaller than that at high speed. The flame stability zone formed at high inlet velocity is more stable and has stronger resistance to external disturbance. When the ratio of oil and gas mixtures is in the flammability limit range, the selection of ignition position has an important influence on the success of ignition. When the high-temperature zone formed by the initial ignition core can be diffused into the reflux zone and maintain sufficient temperature, the ignition can be successful.
Buckling and Post-buckling Analysis of Composite Hat Stiffened Panels under Axial Compression Loads
Authors: Wang Zhe , Wang Binwen , Bao Rui , Chen Xiangming , Liang Qingxianglong , Yu Fei 
Published: May 2023

Abstract
Owing to their unique material design-ability and excellent weight reduction properties of carbon fibre reinforced polymers(CFRP), commercial aircraft OEMs have been innovating design and manufacturing approaches to wider the application of advanced composites. In this paper, the bearing capacity of composite hat-stiffened panels is determined by an improved engineering calculation method and numerical analysis method. The effectiveness of both methods is verified by the test. The advantage of the engineering estimation method is simple and fast, which is suitable for the parametric analysis of the structure in the preliminary design phase. The finite element method can better simulate the test process and is suitable for the comprehensive evaluation of structural strength. The combination of the two methods has a high reference value for rapid design and selection.
Numerical Analysis of Pressure Load on Hypersonic Wing
Authors: Chao Zheng , Jiang Shubo , Zhang Guangming 
Published: May 2023

Abstract
The flight vibration environment of hypersonic vehicles has always been a hot topic in the field of aerospace at home and abroad. In this paper, the simple wing model and the outer flow field grid of the wing are established by using fluent software. A series of environmental parameter conditions are set in the hypersonic flow field, and the steady and unsteady flow fields are analyzed. The distribution characteristics of the pressure load on the wing surface in the hypersonic flow field are obtained. The results show that the pressure load measured at the head position of the wing model is larger, and the pressure load at the fuselage position is smaller and changes more gently. With the increase of Mach number, the pressure load on the wing model will also increase. Then MatLab software is used to convert the time domain curve of wing surface pressure load into a power spectral density curve, which provides load input for subsequent random vibration response simulation on finite element software.