bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microclimate modelling and hygrothermal investigation of freeze-thaw degradation under future climate scenarios
Authors: Mandinec Jan , Johansson Pär 
Published: December 2023

Abstract
Future climate scenarios lead to changes in the boundary conditions impacting the service life of building envelopes. This may increase or decrease the risk of degradation caused by e.g., freezing and thawing on brick façades. In this study, the risk of degradation based on individual years is compared for different moisture reference year (MRY) selection methods. Furthermore, two new MRY indices, based on the Frost Decay Exposure Index (FDEI), are proposed to assess future climate scenarios. A brick façade in Gothenburg, Sweden, is used as a case study to investigate the microclimate caused by façade orientation and solar radiation on three different parts of the façade. The risk of damage is compared for climate scenarios A1B and A2 from 1961 to 2100. The microclimate of the façade is modelled to obtain boundary conditions for each part instead of using MRYs as uniform boundary conditions for the whole building. The study demonstrates a 67% difference in risk of degradation between the different parts of the façade. Furthermore, the risk of freeze-thaw degradation reduces in the future. Finally, it is indicated that the basic FDEI index is better at evaluating the severity of exposure compared to its derivatives.
Impact of Tree Leaf Area Density on Cooling and Ventilation of an Urban Neighborhood
Authors: Kubilay A , Strebel D , Derome D , Carmeliet J 
Published: December 2023

Abstract
The impact of trees during heat waves can be diverse, as their interaction with their surroundings depends on several parameters that modify shading, ventilation potential and transpiration rate. A multiscale coupled model is presented that allows the detailed analysis of the local impact of vegetation as a mitigation measure for urban heat islands. A case study is performed on an urban neighborhood in Zurich, Switzerland, with an aim to improve the understanding of physical processes in urban microclimate subjected to a heat wave. A parametric study presents the impact of varying the leaf area density (LAD) of the existing trees in the neighborhood. Comparisons of surface temperatures and rate of transpiration with available measured data show a good agreement. The results show that urban trees can reduce heat storage during the day due to shadowing, especially when they are in groups. The reduction in air temperature due to transpiration largely depends on LAD, wind-flow patterns and urban morphology. The results also indicate locations with an increase in air temperature due to the presence of trees.
DC line fault discrimination based on maximum information coefficient
Authors: Yu Jiang , Dou Zhenlan , Chen Wei , Sun Pei , Chen Haotian , Duan Yahui 
Published: December 2023

Abstract
In DC networks, conventional line differential protection has the disadvantages of low reliability, weak resistance to transition resistance, and vulnerable to harmonic interference. In this paper, a fault identification method based on maximal information coefficient (MIC) is proposed for non-high resistance faults in the DC side of a flexible DC distribution network containing a modular multilevel converter (MMC) with single pole grounding DC protection inside and outside segments. The failure prediction is performed based on the reciprocal information at two sides of the line current. At the same time, for single-pole grounded high-resistance faults, the MIC is compared using the zero moduli of the current at two sides of the line for the recognition of high-resistance faults. The MMC-based flexible DC transmission network model is built and validated in the PSCAD/EMTDC platform. The results show that the method can identify faults protection inside and outside segments on the DC line area quickly and reliably. It also has the ability to resist harmonic interference and has an endurance of resistance for single-pole faults on the DC side; meanwhile, for high-resistance faults, it can also be detected accurately.
Research and Implementation of a High-efficiency and Intelligent Power Supply System for Radio Equipment
Authors: Wang Xiaoshuang , Zhao Jing , Rao Xuejun , Qi Lihua 
Published: December 2023

Abstract
The use of nickel-metal hydride batteries in tactical radios will lead to problems such as heavier loads, shorter battery life, and less intelligent power supply systems. Because analyzing the power supply guarantee requirements of tactical radio stations, this paper firstly models and simulates lithium-ion batteries to accurately estimate key design parameters such as lithium-ion power and balance control. Then, high-efficiency integration technologies of new materials such as PAA and LiPF6 are used to develop lithium-ion batteries with high specific energy density, good high and low-temperature performance, and lightweight. At the same time, DSP technology is used to develop battery fast charging and intelligent management software and hardware systems to achieve fast and real-time detection of battery state of charge, health state, and functional state. The battery-intelligent power supply system will provide theoretical guidance and technical support for the overall improvement of the combat effectiveness of tactical radio equipment.
Adaptability Analysis of Distribution Network Protection Technology Considering Distributed Photovoltaic Power Generation Access
Authors: Liu Jinjie , Song Xiaohui , Gao Fei , Li Yajie , Wu Yan 
Published: December 2023

Abstract
The integration of distributed power sources into the distribution network has transformed the traditional radial topology structure of the distribution network into a multi-source structure, which can lead to a series of problems, such as voltage violations and bidirectional power flow in the lines. This situation presents a significant challenge to traditional distribution network protection technology. Therefore, based on the electrical characteristics of random loads and distributed power sources, the impact of distributed power source integration on fault characteristics and protection is analyzed, and the adaptability of different distribution network protection methods to distributed power source integration is evaluated. Key factors for improving the protection action characteristics of the distribution network are proposed.
High-precise Motion Control Hardware System and Key Timing Management Research
Authors: Yan Honglei , Lu Hailiang 
Published: December 2023

Abstract
High-precise and multi-axes motion control system is required in the application of semiconductor equipment and high-performance industrial equipment. To achieve the tight performance requirements, this paper presents the control system architecture, communication, and timing management solution. We use multiple cores DSP and FPGA as the main control chips, use SRIO @5Gbps *4 as the DSP and FPGA communication protocol, and use Aurora 8B/10B @5Gpbs as the inter-board communication protocol. This architecture with its high sampling rate and low latency can improve the motion control performance and raise the system sampling bandwidth. Analysis and test results of system communication and timing management are included to demonstrate the efficacy of the proposed scheme.
Time of Flight Measurement Method Combining Threshold Method and Cross-Correlation Method
Authors: Zhu Mingrui , Zhou Hongliang 
Published: December 2023

Abstract
With various benefits such as a large range ratio, suitability for large-diameter measurement, and lack of excess pressure drop, ultrasonic flowmeters (UFMs) have been widely adopted in natural gas measurement. The accuracy of flow measurement in transit-time UFMs is mostly dependent on the accurate measurement of time of flight (TOF). The threshold method, the cross-correlation (CC) method, and the model-based method are examples of traditional TOF calculation techniques. However, the threshold method is susceptible to such factors as waveform distortion, amplitude attenuation, and noise, the CC method is constrained by the sampling frequency, and the model-based method necessitates a significant investment in calculation time and resources. Based on the analysis of the shortcomings of traditional TOF measurement methods, a TOF measurement method that combines the threshold method and CC method is presented. This method integrates the advantages of the high measurement resolution of the threshold method and the strong robustness of the CC algorithm. The results demonstrate that the flow rate accuracy and the repeatability of the TOF are greatly improved by this method.
Statistical Analysis of Step Stress Acceleration Test Data
Authors: Yan Kejian , Feng Anping , Yang Man 
Published: December 2023

Abstract
The step stress accelerated life test is the selection of a set of accelerated stress levels that are higher than normal stress levels. At the beginning of the test, a certain number of samples are placed under a certain stress level for life testing. After some time, the stress level is increased, and this continues until a certain number of samples fail. In this paper, the acceleration coefficient is used to convert the failure data under each acceleration stress level into life data. The life distribution is exponential distribution, Weibull distribution, and logarithmic normal distribution. Under a certain number of samples, the statistical analysis of step stress accelerated life test data is completed, and the estimation of each reliability index is calculated.
Design of Fuzzy Controller for Lithium Battery Formation LLC Converter Based on Sparrow Search Algorithm Optimization
Authors: Li Hongyan , Li Yongming , Xie Zhen 
Published: December 2023

Abstract
This paper provides a novel fuzzy PI controller design for LLC resonant converters that make use of the sparrow search algorithm optimization. The LLC resonant converter is a complex nonlinear and time-varying system. As the trend in lithium battery energy conversion systems shifts toward high-power applications, they frequently encounter wide load variations. When employing traditional linear PI controllers of LLC resonant converters, the transient response is slow and fails to adapt effectively to the requirements of wide load changes. In this proposed approach, fuzzy control and PI control are combined to enhance the controller’s flexibility and transient response characteristics. The PI controller parameters are continuously adjusted online, incorporating fuzzy control outputs to improve the controller’s performance. Furthermore, the sparrow search algorithm is applied to optimize the proportional and quantization factors, minimizing the impact of improper parameter selection on the performance of the fuzzy PI controller. This method successfully addresses the challenges posed by the LLC resonant converter, improving adaptability and transient response characteristics in varying load conditions by combining fuzzy control and PI control, online parameter modification, and utilizing the sparrow search algorithm to optimize proportional and quantization factors.
The Effect of 330 kV Porcelain Insulators Deterioration on Distributed Voltage
Authors: Xu Hejie , Wang Sihua 
Published: December 2023

Abstract
As a commonly used insulator type for 330 kV transmission lines, porcelain insulators are susceptible to damage by external forces during operation, resulting in deterioration. The study on the change of the distributed voltage of porcelain insulators in different deterioration states is important for the timely and accurate detection of deteriorated insulators and the maintenance of safe operation of the power grid. This paper establishes a finite element model of a 330 kV AC transmission line. By changing the resistance values of single insulators at different positions in the insulator strings, the distributed voltage variation law of insulators under different deterioration states is simulated. Analysis of the results shows that the voltage drop is higher in the presence of two consecutive degraded insulators than in the case of a single degraded insulator with the same degree of deterioration. The existing criterion of “less than 50% of the standard value of the distributed voltage” for determining insulator degradation is likely to cause misjudgment in the case of high insulation resistance of low-value insulators and needs to be improved.
Control strategy for three-phase four-switch active power filter based on positive sequence extraction in stationary coordinate fundamental reference frame
Authors: Guo Fengfeng , Qiao Jiping , Jia Tianyu , Wang Lei 
Published: December 2023

Abstract
Traditional three-phase four-switch active power filter often uses the method of phase-locked loop (PLL) and low-pass filter for harmonic detection, which seriously affects the detection accuracy. In order to improve the detection accuracy, a lock-free three-phase four-switch active power filter based on fundamental positive sequence extraction is proposed. The harmonic detection adopts the fundamental positive sequence extraction method, and the rotation coordinate axis transformation adopts the phase-locked loop (PLL) free method. Compared with the traditional three-phase four-switch active power filter, this method does not require a phase-locked loop and a low-pass filter, and does not need complex coordinate transformation[2].The control method is simpler. Finally, simulation results prove the effectiveness of the control method.
State of energy estimation of lithium battery based on least squares and support vector regression
Authors: Yao Bowei , Liu Gaoling , Liu Baolei , Zhai Kejiao , Wei Jinyi , Yin Xilin 
Published: December 2023

Abstract
To enhance the estimation precision of lithium battery state of energy (SOE) and avoid the complex modeling and parameter identification process in the estimation process, a joint algorithm using the least square method (LS) and support vector regression (SVR) is proposed in this paper. Data on the voltage, current, temperature, and charge state of the lithium battery are extracted and incorporated into the energy factor. The lithium battery SOE estimation model is designed by the least-squares support vector regression (LS-SVR) methods, while the grid optimization method is deployed to optimize the hyper-parameters. Finally, the SOE prediction of lithium batteries under a dynamic scenario is realized. Comparison results show that the energy factor chosen in our article accurately reflects the SOE of lithium batteries, and the MAE is within 1.5%.
An online diagnosis method for the inter-turn fault of current transformer based on ΔI-E curves
Authors: Zhou Shaoping , Wei Pingan , Li Xiang , Jiang Lan 
Published: December 2023

Abstract
The inter-turn short fault of the secondary coil is the most frequent fault for current transformers. Failure to detect this fault promptly will affect the accuracy of electrical measurement and the correctness of relay protection actions. This paper proposes an online diagnosis method for inter-turn short faults in current transformers. A ΔI-E curve is constructed based on the real signal of the primary winding and the measurement signal of the secondary winding. The working condition of the current transformer is reflected by the change in the curve. Simulation results show that the proposed method can detect the inter-turn short fault of the current transformer online and sensitively, which has certain practical value.
The outflow characteristics of PV water lifting systems based on multiple tracking strategies
Authors: Hu Wei , Hou Shiwen , Zhu Junfeng , Li Liang , Cao Liang , Hao Weigang 
Published: December 2023

Abstract
In order to clarify the problems of high failure rate, low efficiency, and low outflow rate of PV water pumping stations in pastoral areas due to large differences in resource conditions and poor equipment matching, this study uses the PV water supply model, establishes a pilot site for PV human storage water supply in pastoral areas, carries out research on the relationship between solar energy resources, water supply demand and power system of PV water pumping stations based on group observation tests in the field, and analyzes the PV system. We analyzed the relationship between different tracking operation modes and the amount of solar radiation and water supply flow, and compared the outflow characteristics of fixed type, single-axis tracking type, and double-tracking axis type, in order to explore a kind of PV water pumping station technology suitable for human storage and drinking water in pastoral areas, which can meet the water demand of pastoral water users. The research results show that the single-axis and dual-axis water lifting systems are significantly more efficient than the fixed-support water lifting system, receiving solar radiation at more than 80% of the maximum radiation throughout the day, and lifting water flow at more than 90% of the maximum discharge flow. Compared with the fixed-support PV water lifting system, the radiation of the single-axis PV water lifting system increases by 28.9%, and the daily water output increases by 43%; for the dual-axis PV water lifting system, compared with the single-axis PV water lifting system, the daily radiation of the dual-axis PV water lifting system increased by 4.8% and the daily water output increased by 3.2%; the starting radiation of the PV water lifting system was 256 W/m2.
A Coordinated Reclosing Strategy for Maintained Transformer in Offshore Wind Power Systems
Authors: Chen Jixu , Wei Qing , Li Yanna , Zhou Sunpeng , Zhang Ping , Wang Dong 
Published: December 2023

Abstract
Offshore wind power generation system needs to consider the maintained transformers to reclose. The close loop operation can meet the requirement for reclosing the maintained transformer and maximize the use of wind resources without disconnecting wind turbines. However, close loop operation will cause system damping which can easily cause system instability and protection maloperations. To suppress close loop current damping, a flexible reclosing strategy is proposed that coordinates control of the main bus switch and transformer-connected flexible switch which consists of a damping buffer branch and pass branch. The coordinated control of switches realizes the optimized reclosing state of the maintained transformer. Finally, case studies are established in PLECS simulation software to evaluate the effectiveness of the proposed flexible reclosing strategy to eliminate the reclose damping oscillation for maintained transformers in offshore wind power generation systems.
Optimal Configuration of Voltage Sag Monitoring Points Considering Branch Current based on War Strategy Optimization Algorithm
Authors: Shou Shaoan , Luo Hairong , Zhang Renhe , Ji Tao , Liu Quan , Su Liqian 
Published: December 2023

Abstract
In recent years, a large number of distributed power sources have been connected to the power grid, and the power quality problem has been deteriorating. In order to comprehensively evaluate the voltage information and current information and realize the guidance of power quality monitoring, this paper considers the global monitoring of fault points and obtains branch current information as much as possible. The concept of average redundancy is added to establish the optimal configuration model of voltage sag monitor. The model is solved by the war strategy optimization algorithm, and the optimal configuration simulation of IEEE39 nodes is carried out by MATLAB. The optimal configuration scheme of the monitor is obtained, and the feasibility and effectiveness of the scheme are verified.
Capacity Prediction of VRLA Batteries Based on Stepwise Regression Analysis
Authors: Le Xubo , Wang Xueyan , Li Haibo , Zhang Bingye , Zhao Xing , Zou Xiyong 
Published: December 2023

Abstract
Effective maintenance of valve-regulated lead-acid (VRLA) battery groups within substations is critical for DC system reliability. Therefore, assessing battery health and remaining capacity is essential. In this study, we focus on predicting the VRLA battery group remaining capacity and propose a prediction model based on stepwise regression. This model utilizes operational data, combining the charging and discharging characteristics of VRLA batteries. Stepwise regression selects the optimal independent variable subset, mitigating poor predictions from using all variables in multiple linear regression. Experimental results validate the accurate prediction of lead-acid battery capacity decline, offering effective forecasts. This model is expected to be widely applied in the capacity prediction of DC power systems in substations.
Simulation of Different Control Strategies in Pumping Mode of Variable-speed Pumped Storage Unit
Authors: Li Mengjia , Jiang Ningqiang 
Published: December 2023

Abstract
Because of the complex structure, the variable-speed pumped storage (VSPS) unit would face more stability problems in operation compared with conventional generators in the power grid. To overcome the shortcomings of the PI controller, the fractional order PI (FOPI) controller is applied for VSPS in pumping mode. To compare the quality of the two controllers, the WSCC 9-bus system with VSPS is studied under different disturbances. The dynamic performance is evaluated by calculating the integral of time multiplied absolute error criterion (ITAE) of rotor speed and active power of the stator. The result shows that the FOPI control strategy can effectively improve the dynamic performance of VSPS.
Low-carbon Optimization of Distribution Networks under the Consideration of New Energy Integration
Authors: Li Qiang , Jiang Yan , Du Changyu , Zhou Hangyu , Chen Tongxuan 
Published: December 2023

Abstract
Under the background of proposing the dual carbon target and building a new power system, distributed energy and energy storage are widely connected to the distribution network, and how to use distributed energy to realize low-carbon optimization of the distribution network needs to be studied urgently. This paper firstly analyzes the computation method of carbon emission flow from distribution networks and then establishes a node carbon potential model of the energy storage element and a low-carbon optimization model of distribution networks aiming at minimizing carbon emissions. Finally, it is verified through examples that new energy access can promote the low-carbon optimization of distribution networks.
Power Quality Disturbance Detection Based on Partitioning-Improved Empirical Wavelet Transform
Authors: Zhou Ke , Jin Qingren , Mo Zhiyue 
Published: December 2023

Abstract
Power quality is an important indicator to measure the quality of power supply in power grids. With the large evasion accession of new energy sources, its randomness and volatility cause frequent transient power quality problems in power grids. With the large evasion accession of new energy sources, its randomness and volatility cause frequent transient power quality problems in power grids. Aiming at the detection of transient power quality disturbance, this paper proposes the empirical wavelet algorithm which improves the adaptive division. This paper improves the spectrum processing, frequency point selection and frequency band division to improve the adaptive division ability of the algorithm under complex perturbation signals. Combined with the Hilbert transform, a perturbation detection algorithm is proposed based on an improved empirical wavelet algorithm to extract the transient characteristics of the perturbation signal. Through software simulation, this method has good adaptive ability in the face of composite power mass transient disturbance and can accurately extract the transient characteristics of the signal.