bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of nitrogen/oxygen ratios on surface charge distributions generated by repetitive surface dielectric barrier discharges
Authors: Uemura Takuma , Nishida Hiroyuki , Ono Ryo , Komuro Atsushi 
Published: June 2024

Abstract
Studies on the dielectric surface parameters and dielectric barrier discharges (DBD) characteristics considering the influence of gases in DBD on the surface charge distribution are scarce. Thus, to overcome this research gap, this study measured the potential distributions of AC-driven surface DBD in oxygen (O2), synthetic air and nitrogen (N2) as background gases using the Pockels effect. The results showed that the patterns of the filamentary discharges generated during the positive voltage polarity phase differed depending on the O2 ratio. In addition, the electrostatic repulsion forces between the residual charge and the newly created filament were analysed from the measured potential distribution and the greatest effect was observed in air, rather than in N2 and O2. The potential distribution was transformed into a charge density distribution and compared with the discharge luminescence in air and N2. The results showed that the shape of the filament tip differed between the charge density and discharge luminescence only in the case of air, which was attributed to the effect of attachment reactions on the formation of residual charge. The measurements showed that in a surface discharge, similar to the case in a volume discharge, the photoionisation and ionisation coefficients significantly affected the geometrical properties of the discharges.
‘Are you even listening?’ - EEG-based decoding of absolute auditory attention to natural speech
Authors: Roebben Arnout , Heintz Nicolas , Geirnaert Simon , Francart Tom , Bertrand Alexander 
Published: June 2024

Abstract

Objective. In this study, we use electroencephalography (EEG) recordings to determine whether a subject is actively listening to a presented speech stimulus. More precisely, we aim to discriminate between an active listening condition, and a distractor condition where subjects focus on an unrelated distractor task while being exposed to a speech stimulus. We refer to this task as absolute auditory attention decoding. Approach. We re-use an existing EEG dataset where the subjects watch a silent movie as a distractor condition, and introduce a new dataset with two distractor conditions (silently reading a text and performing arithmetic exercises). We focus on two EEG features, namely neural envelope tracking (NET) and spectral entropy (SE). Additionally, we investigate whether the detection of such an active listening condition can be combined with a selective auditory attention decoding (sAAD) task, where the goal is to decide to which of multiple competing speakers the subject is attending. The latter is a key task in so-called neuro-steered hearing devices that aim to suppress unattended audio, while preserving the attended speaker. Main results. Contrary to a previous hypothesis of higher SE being related with actively listening rather than passively listening (without any distractors), we find significantly lower SE in the active listening condition compared to the distractor conditions. Nevertheless, the NET is consistently significantly higher when actively listening. Similarly, we show that the accuracy of a sAAD task improves when evaluating the accuracy only on the highest NET segments. However, the reverse is observed when evaluating the accuracy only on the lowest SE segments. Significance. We conclude that the NET is more reliable for decoding absolute auditory attention as it is consistently higher when actively listening, whereas the relation of the SE between actively and passively listening seems to depend on the nature of the distractor.
A potential optical approach for diagnosis of the local magnetic field near the surface of the first wall/divertor tiles by Zeeman effect using polarization-resolved laser-induced breakdown spectroscopy
Authors: Wu Huace , Wu Ding , Li Cong , Hu Zhenhua , Ding Fang , Hai Ran , Ding Hongbin ,   the EAST Team
Published: June 2024

Abstract
Magnetic field measurement is the basic diagnosis to obtain the physical engineering parameters of magnetic confinement fusion device and the macro information of plasma discharge. The real-time diagnosis of magnetic field distribution near the plasma-facing components (PFCs) surface provides the important information on the migration and transport model of key elements. In this work, a remote, in-situ approach for the magnetic field measurement near the surface of PFCs by the polarization-resolved laser-induced breakdown spectroscopy (LIBS) based on Zeeman effect is proposed and implemented. The Zeeman characteristics of the emission spectra of laser-induced W, Mo and C plasmas were verified in the laboratory by using different magnetic field configurations. According to the polarization characteristics of the Zeeman sublines of the LIBS spectrum, the intensity and direction of the external local magnetic field were successively identified by using a linear polarizer. Subsequently, a linear array fiber was utilized to determine the polarity of the external magnetic field. And finally, the magnetic field intensity near the lower edge surface of the tungsten baffle of the Experimental Advanced Superconducting Tokamak (EAST) upper divertor was measured when the field coils were demagnetized. This method can supplement the experimental data near the PFCs for the magnetic field configuration of the magnetic confinement fusion device and provide a reference for the wall element analysis model diagnosed by LIBS.
Optimal computation of integrals in the Half-Space Matching method for modal simulation of SHM/NDE in 3D elastic plate
Authors: Allouko A. , Bonnet-Ben Dhia A.-S. , Lhémery A. , Baronian V. 
Published: June 2024

Abstract
Simulating structural health monitoring (SHM) or nondestructive evaluation (NDE) methods based on elastic guided waves (GW) is very helpful to handle their complexity (co-existence of several GW modes, frequency dependence of wavespeed) and to further design optimal methods of inspection offering high sensitivity to the sought flaws. The half-space matching (HSM) method has been established for the development of a model that hybridizes local finite element (FE) computations for GW scattering by a flaw, with a modal semi-analytical model for GW radiation and propagation in flawless plate-like structures. Highly oscillatory Integral formulae appear in the HSM method that radiate the scattered field away from the FE zone as the superimposition of modal contributions, which computation can be time-consuming. The present work is concerned with their optimal computation. Integral of this form can be efficiently computed under the far-field approximation but this classical technique fails at predicting accurately wavefields at relatively short distances (small number of wavelengths). The method developed herein relies on the complexification of the integrals to be computed and on specific deformation of integration paths in the complex plane, as detailed in the paper. It allows the evaluation of the integrals without approximation other than that of numerical quadratures, ensuring high accuracy while offering high computing performances. It indifferently applies in the far-field and in the near-field. The method of computation is validated by comparing its predictions with a reference solution of GW scattering. Its computational performances are also demonstrated, compared to those of the standard computation of the HSM integral formulae.
Performance analysis of transcritical CO2 and common medium low-temperature air energy heat pump
Authors: Li Jieru 
Published: June 2024

Abstract
To comply with the development of the “dual-carbon” goal, a new refrigerant for heat pump products is necessary. Firstly, mathematical models of enhanced vapor injection air energy heat pump and transcritical CO2 heat pump systems were established, and they were calculated using thermodynamic methods. The results show that when CO2 is used as the refrigerant, the discharge temperature is 30% and 22.7%, which is higher than that of R410A and R134a, and 4.9% lower than that of R32. At the compressor outlet, the volume flow rate of CO2 is 59.0%, 60.8%, and 64.2% less than R410A, R32, and R134a, respectively. In terms of power consumption, the difference between CO2 and R410 A is within 6%. The power consumption of the CO2 system is 0% ∼ 6.4% higher than that of the R32 system and 29.2% ∼ 46.5% lower than that of the R134a system. The COP of the CO2 system is within 6% of that of the R410A and R32 systems, which is 41% ∼ 87% higher than that of the R134a system. When the ratio of CO2 / R32 is 0 ∼ 0.2 and 0.9, the COP of the mixed refrigerant is better than that of the single refrigerant CO2.
Planning of wind-photovoltaic-storage-hydrogen-water for a zero-carbon microgrid on an independent island
Authors: Liang Fuguang 
Published: June 2024

Abstract
Due to low daily demand and the remote location from the shoreline, diesel generators dominate the energy supply on these islands, resulting in significant emissions of harmful gases. In this paper, a collaborative planning approach is proposed for a zero-carbon microgrid incorporating wind turbines (WTs), photovoltaic modules (PVs), electrochemical energy storages(EESs), hydrogen energy storages(HESs), and sea water desalination on an independent island. Long-term and short-term energy storage mechanisms, represented by HESs and EESs, respectively, are coordinated to harness the abundant wind and solar energy resources. Additionally, consideration is given to the requirement for sea water desalination to achieve a self-sustained equilibrium of zero-carbon water and electricity for the island’s inhabitants. Illustrative analysis demonstrates that the proposed planning method accounts for the stability and environmental preservation in terms of the planning and operation. This has profound implications for advancing the transformation of the island’s microgrid energy infrastructure, enhancing the utilization of renewable energy, and bolstering the self-sustaining capacity of hydropower resources.
Yaw control strategy optimization
Authors: Zhang Yuyang , Li Yiran , Bian Yanfeng 
Published: June 2024

Abstract
In recent years, with the rapid development of large-scale wind turbines, the issue of yaw misalignment has attracted increasing attention. This problem not only reduces the power generation capacity of the turbine but also affects the fatigue load on its blades. Therefore, in this paper, the shortcomings of common yaw control strategies were introduced first, and we propose a decoupling approach for wind direction angle and yaw angle to eliminate physical deviations and improve accuracy in aligning with the wind direction.
Numerical simulation of the influence of different heating directions on charging performance of the cubic combined sensible-latent heat storage structure
Authors: Liu Yuanqing , Wu Yuting , Ma Chongfang 
Published: June 2024

Abstract
The sensible and latent heat storage system (CSLHS) has become a research hotspot. In this paper, we construct a thermal storage unit structure by using the method of cubic macro-encapsulation, and its charging performance is simulated by CFD. The material of sensible heat storage is magnesia brick or concrete, and the material of the latent heat storage is molten salt. First, we analyze the effects of different heat surfaces on the charging performance of the CSLHS. The charging performance is better when heating from the bottom than when heating from the top or the side. Then, the heat storage of concrete brick and CSLHS is compared, under the premise of heating from the bottom surface. When the PCM starts to melt, the heat transfer inside the hybrid configuration is 39% higher than the solid heat storage structure. When the heat storage is nearing completion, its temperature distribution is more uniform than the solid heat storage structure, and its heat transfer inside the hybrid configuration is at the same level as the concrete.
Under-frequency load shedding setting method of new energy sending-end system based on improved IMQ-GWO algorithm
Authors: Wang Haijun , Xu Tao , Li Yang , Li Chencheng , Zhu Lin 
Published: June 2024

Abstract
Aiming at the problems of low qualification rate, poor stability, and insufficient timeliness of the existing under-frequency load shedding implementation scheme at the new energy sending end, this paper proposes an under-frequency load shedding setting method for the new energy sending end system based on the improved IMQ-GWO algorithm. Firstly, considering the fluctuation of the trend of the line of the sending end system relative to the load curve of the whole network, the index system of the implementation scheme based on the under-frequency load shedding is established. Secondly, the objective function is established for the index system of the under-frequency load shedding scheme, and the under-frequency load shedding setting model is established considering the static constraints and transient constraints of the system. Then, the grey wolf optimization algorithm (GWO) is updated by using the characteristics of the IMQ function. At the same time, the individual position is adaptively updated based on the Sigmoid exponential function to better search and optimize the solution space of the problem. Finally, based on the modified IEEE39 node, the empirical analysis is carried out, and the improved IMQ-GWO algorithm proposed in this paper is used to solve the under-frequency load shedding setting model. It is proved that the proposed method is superior to other methods in terms of execution qualification rate, stability, and application timeliness.
Reliability analysis method of energy storage stations considering the correlation of battery clusters
Authors: Zhan Hua 
Published: June 2024

Abstract
In the context of dual carbon, in order to address the volatility of new energy output, energy storage power stations (ESPSs) are thriving. However, it is challenging to assess the dependability of ESPS operation because of the steady functioning of individual battery clusters (BCs), which will have an impact on how safely and steadily the power system is evaluated. Therefore, a reliability model for energy storage BC units based on the structural analysis of battery structure modules is constructed in this manuscript. Then, a method for constructing a correlation model of energy storage units based on the Copula function was proposed. Finally, a simulation analysis based on the ESPSs of pertinent demonstrative application projects in Fujian Province is used as an example to confirm the viability and efficacy of the proposed reliability analysis approach.
Analysis of frequency characteristics of power system with wind farm-energy storage coordinated inertial control
Authors: Liang Zhanhao , Yang Shuangfei , Zhou Yuebin , Zeng Jun , Liu Junfeng 
Published: June 2024

Abstract
With the increasing penetration level of wind power in the power system, the decoupling of wind turbine rotor speed and system frequency has led to the loss of the inertia of wind farms (WF), which can no longer be neglected. With the continuous development of energy storage (ES) technology, WF-ES coordinated inertial control has attracted attention as an effective means for wind turbines (WT) to participate in inertia response. How to build a WF-ES coordinated inertial control strategy and analyze system frequency characteristics has become a key research issue. In this paper, the frequency response model of a power system with WF-ES is established using the system frequency characteristic analysis method. The wind speed zones of the WF are taken into account, and different WF-ES control schemes are adopted under different wind speeds, aiming to ensure the active participation of WTs in the system frequency process across all wind speed conditions and effectively prevent frequency secondary drop. Finally, a power system frequency response simulation model is built in Matlab/Simulink to analyze the frequency characteristics of the power system with WF-ES coordinated inertial control and verify the feasibility of the proposed WF-ES coordinated inertial control strategy under various wind speeds.
Thermal design calculation method of the whole coil closed cooling tower with condensation inside the tube
Authors: Jing Xuehui , Liu Yin , Yang Zepeng , Wang Zhiyun 
Published: June 2024

Abstract
In this paper, the heat exchange process of a closed cooling tower with condensation inside the tube is analyzed. Combined with the calculation method of a traditional closed cooling tower, the thermal model and mathematical model of the whole coil closed cooling tower with condensation inside the tube are established. The fourth-order Runge-Kutta (RK4) method is used to write a program to solve the differential equation. A case is calculated to solve the heat exchange area and spray water temperature. Its feasibility for design reference is verified.
Fault diagnosis study of ship solar photovoltaic power generation system
Authors: Ren Xinyue , Guo Yi , Gong Yiting 
Published: June 2024

Abstract
In this paper, a fault diagnosis method of ship photovoltaic (PV) power generation system based on a convolutional neural network (CNN) is proposed to ensure the smooth navigation of ships. Firstly, to understand the normal operation and fault state of the generation system, a simulation model of the photovoltaic power generation system is constructed using MATLAB / Simulink. Then, the model is simulated to extract the fault data under different fault conditions, and the eigenvalue extraction of the fault data is carried out by using the fast Fourier transform method. Following that, a fault diagnosis model is built using the convolutional neural network and trained accordingly. The final diagnostic results show that the established simulation model and convolutional neural network can provide support for the fault diagnosis of ship photovoltaic power generation system, and can autonomously detect the type of faults and locate the location of the faults after the faults occur in the generation system, to ensure the stable and safe operation of ship power generation system.
Research on method of identifying cable-releasing logic defects in wind turbines
Authors: Yang Yufan , Rong Xinhan , Zhang Yuyang 
Published: June 2024

Abstract
The yaw system of a wind turbine is one of the important components that ensures the normal operation of the turbine and has a significant impact on the power generation of the turbine. Currently, there is little research on the cable-releasing logic in the yaw system. This paper analyzes the possible logical defects in the cable-releasing system and examines the cable-releasing logic of the turbine by using a method based on its operational logic. By subdividing the turbine’s state using information such as power, wind speed, and yaw angle from operational data, abnormal cable-releasing events can be identified through logical filtering to detect whether there are logical defects in the turbine’s cable-releasing logic. The reliability of the method was verified by using examples from turbines that did have cable-releasing logic defects.
Grid control strategy of wind turbines based on LADRC voltage control
Authors: Li Wenbiao , Zhou Xiaolong , Meng Yanfeng , You Jie 
Published: June 2024

Abstract
Traditional grid-controlled wind turbines are required to rely on AC power grid operation, but when the power grid fluctuates, it will cause a series of oscillation instability problems in wind turbines, such as low-frequency oscillation, subsynchronous oscillation, etc. The safe and stable operation of the crisis power grid needs to be ensured. In this study, the virtual synchronous machine is supposed to be adopted as the main control strategy for grid-type control, transforming the traditional system into a more robust and reliable one. Additionally, a converter model of the grid-type control network is set up. By implementing grid-type control, voltage support and frequency support can be offered without relying solely on AC power grid operation. This approach effectively addresses issues caused by preventive such as reliance on wind turbines. The stability of the networked control system is dependent on maintaining stable system power. When there are fluctuations in system power, it impacts the stability of the networked control system. To mitigate these effects and enhance overall stability, this paper proposes using linear active disturbance rejection control (LADRC) based voltage and grid controls to suppress voltage fluctuations through linear active disturbance rejection techniques. The overall system performance is demonstrated through simulations conducted using Matlab/Simulink platform.
Study on the effect of PV tilt angle on power generation
Authors: Chen Qiuluan , Cai Zhen , Han YingZhi , Zhang Mian , Li BenXiong , Luo Linshiyi 
Published: June 2024

Abstract
The power generation of a photovoltaic (PV) system is significantly influenced by the tilt angle of the module. The system achieves the highest power efficiency when operated at the optimal tilt angle, which is typically considered in the design of system installation. In this study, the optimal tilt angle of photovoltaic (PV) modules is determined by using PVsyst software and analyzed through shadow simulation under specific boundary conditions. The study examines the power generation of photovoltaic (PV) panels at various inclination angles and illustrates the impact of inclination angle on PV panel power generation by using project-specific data. The study results indicate that the secondary optimization of the tilt angle by PVsyst, in conjunction with the geographic factors of a specific region in Hainan, reveals that the optimal installation tilt angle for maximum power generation benefit is 9°. This finding aligns with the best power generation and benefits from the actual installation, which is at 10° (adjacent to 9°). The conclusions drawn from the exploration emphasize the essential nature of EPC optimization for future projects, as it can serve as a valuable reference for the design of photovoltaic power generation systems.
Research on pinch analysis of union station a subsystem
Authors: Chen Guofu , Liu Daoqin , Wang Zhaoliang 
Published: June 2024

Abstract
To realize the cascade utilization of energy from the subsystem of Union Station A and improve the extraction of residual heat from sewage in the oilfield, this paper presents a process flow chart based on the Union Station A subsystem and analyses the energy flow of the entire Union Station A subsystem through the method of pinch analysis. In this study, we examine the energy flow distribution across the temperature spectrum within the system, identify the system’s energy consumption “bottleneck”, and optimize the system. The optimization findings reveal that the appropriate range for the pinch point temperature difference in the distributed energy system of the station is 8 to 14°C, with an associated energy-saving potential of 2.73%.