Accurate prediction of the remaining useful life (RUL) of energy storage batteries plays a significant role in ensuring the safe and reliable operation of battery energy storage systems. This paper proposes an RUL prediction framework for energy storage batteries based on INGO-BiLSTM-TPA. First, the battery’s indirect health index is extracted by combining principal component analysis and the Pearson correlation coefficient in the battery charge/discharge cycle data. Second, for the problem that the Northern Goshawk Optimization (NGO) algorithm is prone to falling into local optimum, the Gaussian variation mechanism and nonlinear hunting radius are introduced to improve the NGO algorithm, and the Improved Northern Goshawk Optimization (INGO) algorithm is proposed. Finally, the temporal pattern attention (TPA) mechanism is introduced in the bi-directional long short-term memory (BiLSTM), which makes the model weighted to focus on the features of important time steps, and the INGO algorithm is applied to it to build the RUL prediction framework. Based on the CALCE battery dataset, the root-mean-square error (RMSE) of RUL prediction based on the proposed framework is controlled within 1.3%, which provides better prediction accuracy and generalization.
{"title":"A novel hybrid framework for predicting the remaining useful life of energy storage batteries","authors":"Yuheng Yin, Minghui Yang, Jiahao Song","doi":"10.1063/5.0221822","DOIUrl":"https://doi.org/10.1063/5.0221822","url":null,"abstract":"Accurate prediction of the remaining useful life (RUL) of energy storage batteries plays a significant role in ensuring the safe and reliable operation of battery energy storage systems. This paper proposes an RUL prediction framework for energy storage batteries based on INGO-BiLSTM-TPA. First, the battery’s indirect health index is extracted by combining principal component analysis and the Pearson correlation coefficient in the battery charge/discharge cycle data. Second, for the problem that the Northern Goshawk Optimization (NGO) algorithm is prone to falling into local optimum, the Gaussian variation mechanism and nonlinear hunting radius are introduced to improve the NGO algorithm, and the Improved Northern Goshawk Optimization (INGO) algorithm is proposed. Finally, the temporal pattern attention (TPA) mechanism is introduced in the bi-directional long short-term memory (BiLSTM), which makes the model weighted to focus on the features of important time steps, and the INGO algorithm is applied to it to build the RUL prediction framework. Based on the CALCE battery dataset, the root-mean-square error (RMSE) of RUL prediction based on the proposed framework is controlled within 1.3%, which provides better prediction accuracy and generalization.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"26 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142224310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pham Van Thach, Satoshi Sumi, Kenji Tanabe, Hiroyuki Awano
We investigated current-induced domain wall motion (CIDWM) driven by spin–orbit torque and Dzyaloshinskii–Moriya interaction (DMI) in ferrimagnetic Pt/GdFeCo/SiN and Rh/GdFeCo/SiN wires with perpendicular magnetic anisotropy at room temperature. We found that CIDWM in the Pt/GdFeCo wire exhibits nearly two times smaller in critical current density and about four times larger in DW mobility compared to the Rh/GdFeCo wire. By measuring the CIDWM under a longitudinal in-plane magnetic field, the DMI constant (D) was estimated for both wires. The estimated value of D for the Pt/GdFeCo wire is approximately seven times larger than the Rh/GdFeCo wire. It indicated that the Pt/GdFeCo wire revealed the CIDWM with much higher efficiency, mainly attributed to the much larger DMI, which may come from significantly stronger interfacial heavy metal/ferrimagnet hybridization in the Pt/GdFeCo wire.
{"title":"Current-induced domain wall motion driven by spin–orbit torque and Dzyaloshinskii–Moriya interaction in Pt/GdFeCo and Rh/GdFeCo wires","authors":"Pham Van Thach, Satoshi Sumi, Kenji Tanabe, Hiroyuki Awano","doi":"10.1063/5.0210487","DOIUrl":"https://doi.org/10.1063/5.0210487","url":null,"abstract":"We investigated current-induced domain wall motion (CIDWM) driven by spin–orbit torque and Dzyaloshinskii–Moriya interaction (DMI) in ferrimagnetic Pt/GdFeCo/SiN and Rh/GdFeCo/SiN wires with perpendicular magnetic anisotropy at room temperature. We found that CIDWM in the Pt/GdFeCo wire exhibits nearly two times smaller in critical current density and about four times larger in DW mobility compared to the Rh/GdFeCo wire. By measuring the CIDWM under a longitudinal in-plane magnetic field, the DMI constant (D) was estimated for both wires. The estimated value of D for the Pt/GdFeCo wire is approximately seven times larger than the Rh/GdFeCo wire. It indicated that the Pt/GdFeCo wire revealed the CIDWM with much higher efficiency, mainly attributed to the much larger DMI, which may come from significantly stronger interfacial heavy metal/ferrimagnet hybridization in the Pt/GdFeCo wire.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"230 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142224312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rohan Kumar, Muhammad Asim, Ammara Kanwal, Muhammad Jawad, Mohsin Pervez
Despite efforts made over the past two decades, Pakistan continues to face electricity crises. The heavy reliance on fossil fuels, which make up 60% of the country’s energy mix, has raised concerns about energy security and environmental degradation due to greenhouse gas (GHG) emissions. Developing effective electricity generation scenarios has been challenging for policymakers and researchers, despite the steady increase in electricity demand. The LEAP software was used in this study to forecast the country’s power demand, and four supply-side scenarios were constructed and examined for the years 2018 through 2040. These scenarios include a baseline scenario, a renewable energy scenario, a more renewable energy scenario, and a near-zero emission scenario, focusing on electricity generation and carbon emissions. The study’s findings, projecting into 2040, indicate that the renewable energy scenarios are environmentally sustainable, with lower GHG emissions compared to the baseline scenario. According to the findings of this study, it is projected that around 615 TWh (terawatt-hours) of renewable energy and nuclear energy will be necessary by the year 2040. The anticipated contributions include 393 TWh from hydroelectric energy, 57 TWh from wind energy, 41 TWh from solar energy, and 62 TWh from other renewable sources. The surge in renewable energy is forecasted to bring near-zero CO2 emissions by 2040, a pivotal step toward a sustainable energy future. A projected energy generation of 615 TWh is expected, which adequately meets the country’s energy demand. Transition to renewable energy is critical for addressing Pakistan’s increasing electricity demands, emphasizing both energy security and environmental sustainability.
{"title":"Toward a renewable future: Attaining 100% renewable electricity generation through sustainable transition","authors":"Rohan Kumar, Muhammad Asim, Ammara Kanwal, Muhammad Jawad, Mohsin Pervez","doi":"10.1063/5.0208838","DOIUrl":"https://doi.org/10.1063/5.0208838","url":null,"abstract":"Despite efforts made over the past two decades, Pakistan continues to face electricity crises. The heavy reliance on fossil fuels, which make up 60% of the country’s energy mix, has raised concerns about energy security and environmental degradation due to greenhouse gas (GHG) emissions. Developing effective electricity generation scenarios has been challenging for policymakers and researchers, despite the steady increase in electricity demand. The LEAP software was used in this study to forecast the country’s power demand, and four supply-side scenarios were constructed and examined for the years 2018 through 2040. These scenarios include a baseline scenario, a renewable energy scenario, a more renewable energy scenario, and a near-zero emission scenario, focusing on electricity generation and carbon emissions. The study’s findings, projecting into 2040, indicate that the renewable energy scenarios are environmentally sustainable, with lower GHG emissions compared to the baseline scenario. According to the findings of this study, it is projected that around 615 TWh (terawatt-hours) of renewable energy and nuclear energy will be necessary by the year 2040. The anticipated contributions include 393 TWh from hydroelectric energy, 57 TWh from wind energy, 41 TWh from solar energy, and 62 TWh from other renewable sources. The surge in renewable energy is forecasted to bring near-zero CO2 emissions by 2040, a pivotal step toward a sustainable energy future. A projected energy generation of 615 TWh is expected, which adequately meets the country’s energy demand. Transition to renewable energy is critical for addressing Pakistan’s increasing electricity demands, emphasizing both energy security and environmental sustainability.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"29 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142185423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Extracellular diffusion coupled with degradation is considered a dominant mechanism behind the establishment of morphogen gradients. However, the fundamental nature of these biophysical processes, visa viz, the Bicoid (Bcd) morphogen gradient, remains unclear. Fluorescence correlation spectroscopy has recently revealed multiple modes of Bcd transport at different spatial and temporal locations across the embryo. Here, we show that these observations are best fitted by a model fundamentally based on quantum mechanics. It is thus hypothesized that the transient quantum coherences in collaboration with unitary noise are responsible for the observed dynamics and relaxation to a non-equilibrium steady-state of the Bcd morphogen gradient. Furthermore, simulating the associated probability distribution for the model shows that the observed non-zero concentration of the Bcd molecules in the posterior-most parts of the embryo is a result of non-Gaussian distribution characteristic to quantum evolution. We conclude that with the Bcd gradient being essentially a one-dimensional problem, a simple one-dimensional model suffices for its analysis.
{"title":"Multiple dynamic modes of Bicoid morphogen gradient are explained by a quantum-classical model","authors":"Irfan Lone, Carl O. Trindle","doi":"10.1063/5.0221207","DOIUrl":"https://doi.org/10.1063/5.0221207","url":null,"abstract":"Extracellular diffusion coupled with degradation is considered a dominant mechanism behind the establishment of morphogen gradients. However, the fundamental nature of these biophysical processes, visa viz, the Bicoid (Bcd) morphogen gradient, remains unclear. Fluorescence correlation spectroscopy has recently revealed multiple modes of Bcd transport at different spatial and temporal locations across the embryo. Here, we show that these observations are best fitted by a model fundamentally based on quantum mechanics. It is thus hypothesized that the transient quantum coherences in collaboration with unitary noise are responsible for the observed dynamics and relaxation to a non-equilibrium steady-state of the Bcd morphogen gradient. Furthermore, simulating the associated probability distribution for the model shows that the observed non-zero concentration of the Bcd molecules in the posterior-most parts of the embryo is a result of non-Gaussian distribution characteristic to quantum evolution. We conclude that with the Bcd gradient being essentially a one-dimensional problem, a simple one-dimensional model suffices for its analysis.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"20 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142224311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Veerappan, Kamaraj Logesh, V. Mohanavel, M. Ravichandran, Ahmed Ahmed Ibrahim, Salahuddin Khan, S. Suresh Kumar, Sathish Kannan, Jayant Giri
Waspaloy, a nickel-based super alloy, has much potential in gas turbine component production. Machining this type of material using the traditional manufacturing method is very hard. Hence, electrical discharge machining (EDM) was selected for the investigation of the machining characteristics of Waspaloy by choosing the control parameters, namely, current, voltage, pulse on time, pulse off time, and spark gap. Gray relational analysis is carried out using 18 experiments according to an orthogonal array (L18) to determine the gray relation grade for this machining process with multiple machining characteristics such as material removal rate (MR), tool wear rate (TW), and surface roughness (SR). The significant objective of the multi objective optimization to attain high MR, low TW, and low SR is found out. From gray relation optimization, the optimum machining conditions for EDM, namely, current: 26 A, voltage: 200 V, pulse on time: 120 μs, pulse on time: 10 μs, and spark gap: 0.15 m, have been identified. The foremost parameter affecting the responses was found to be peak current.
{"title":"Investigation on materials removal rate and surface roughness of temperature resisted Waspaloy during electric spark machining utilizing gray relational analysis","authors":"G. Veerappan, Kamaraj Logesh, V. Mohanavel, M. Ravichandran, Ahmed Ahmed Ibrahim, Salahuddin Khan, S. Suresh Kumar, Sathish Kannan, Jayant Giri","doi":"10.1063/5.0220951","DOIUrl":"https://doi.org/10.1063/5.0220951","url":null,"abstract":"Waspaloy, a nickel-based super alloy, has much potential in gas turbine component production. Machining this type of material using the traditional manufacturing method is very hard. Hence, electrical discharge machining (EDM) was selected for the investigation of the machining characteristics of Waspaloy by choosing the control parameters, namely, current, voltage, pulse on time, pulse off time, and spark gap. Gray relational analysis is carried out using 18 experiments according to an orthogonal array (L18) to determine the gray relation grade for this machining process with multiple machining characteristics such as material removal rate (MR), tool wear rate (TW), and surface roughness (SR). The significant objective of the multi objective optimization to attain high MR, low TW, and low SR is found out. From gray relation optimization, the optimum machining conditions for EDM, namely, current: 26 A, voltage: 200 V, pulse on time: 120 μs, pulse on time: 10 μs, and spark gap: 0.15 m, have been identified. The foremost parameter affecting the responses was found to be peak current.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"41 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142224313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuntong Ma, Zepeng Lv, Yining Zhang, Jinyang Peng, Yi Ge, Kai Wu, Yonghong Cheng
To study the current response to space charge in oil–paper insulation, a simultaneous space charge and external current measurement system are developed for a solid–liquid sample. The space charge and external current of oil-immersed paper are tested under different applied voltages. In the oil–paper sample, it accumulates heterocharge at 0.25 kV and homocharge at a higher voltage. The external currents first decrease and then increase with time. The changing timepoint decreases with the applied voltage. It shows that dynamic space charge evolution influences external current development. An unusual phenomenon is observed that the charge on both electrodes increases without heterocharge accumulation in a certain time range after voltage application, resulting in an increase in the average electric field. The transient electric field and displacement current at the cathode are calculated according to the amount of surface charge at the cathode. It indicates that displacement current takes up the main part of external current and decreases to zero when the surface charge amount stops increasing. After this stage, the conduction current is almost equal to the external current. The correlation between conduction current and electric field is analyzed. It reveals that when the electric field is lower than 5 kV/mm, the conduction current of oil–paper seems to be linear to the electric field strength, following Ohm’s law. When the electric field is higher than 5 kV/mm, the conduction current of oil–paper follows the Fowler–Nordheim law that the ln(jc/E2) is linear to 1/E. The transient external current has great potential in diagnosing electrical equipment.
{"title":"Analysis of space charge and current characters of oil-immersed-paper with simultaneous measurement","authors":"Yuntong Ma, Zepeng Lv, Yining Zhang, Jinyang Peng, Yi Ge, Kai Wu, Yonghong Cheng","doi":"10.1063/5.0215303","DOIUrl":"https://doi.org/10.1063/5.0215303","url":null,"abstract":"To study the current response to space charge in oil–paper insulation, a simultaneous space charge and external current measurement system are developed for a solid–liquid sample. The space charge and external current of oil-immersed paper are tested under different applied voltages. In the oil–paper sample, it accumulates heterocharge at 0.25 kV and homocharge at a higher voltage. The external currents first decrease and then increase with time. The changing timepoint decreases with the applied voltage. It shows that dynamic space charge evolution influences external current development. An unusual phenomenon is observed that the charge on both electrodes increases without heterocharge accumulation in a certain time range after voltage application, resulting in an increase in the average electric field. The transient electric field and displacement current at the cathode are calculated according to the amount of surface charge at the cathode. It indicates that displacement current takes up the main part of external current and decreases to zero when the surface charge amount stops increasing. After this stage, the conduction current is almost equal to the external current. The correlation between conduction current and electric field is analyzed. It reveals that when the electric field is lower than 5 kV/mm, the conduction current of oil–paper seems to be linear to the electric field strength, following Ohm’s law. When the electric field is higher than 5 kV/mm, the conduction current of oil–paper follows the Fowler–Nordheim law that the ln(jc/E2) is linear to 1/E. The transient external current has great potential in diagnosing electrical equipment.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"18 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141943463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, a numerical computation method for the Gierer–Meinhardt model in two-dimensional space diffusion with homogeneous Neumann boundary conditions, considering the interaction between activator and inhibitor substances, is proposed. First, a high-order compact finite difference scheme is constructed for the Gierer–Meinhardt model using the finite difference method. A fourth-order compact difference scheme is applied to the second-order spatial derivative terms, while the time derivative terms are discretized using Taylor series expansion and residual correction functions. Consequently, the difference scheme achieves fourth-order accuracy in space and second-order accuracy in time for the Gierer–Meinhardt model. In addition, the stability of the difference scheme is demonstrated using Fourier analysis. Finally, numerical simulations are conducted on the Gierer–Meinhardt model near its equilibrium point to explore the impact of the inhibitor degradation rate, denoted as E, on the pattern formation. The model exhibits distinct pattern structures with varying E, thereby revealing the relationship between tissue variability and pattern formation in biological systems.
本文提出了一种考虑到激活剂和抑制剂物质之间相互作用的二维空间扩散中具有均质 Neumann 边界条件的 Gierer-Meinhardt 模型的数值计算方法。首先，利用有限差分法为 Gierer-Meinhardt 模型构建了一个高阶紧凑有限差分方案。对二阶空间导数项采用四阶紧凑差分方案，对时间导数项采用泰勒级数展开和残差修正函数进行离散化。因此，差分方案实现了 Gierer-Meinhardt 模型的空间四阶精度和时间二阶精度。此外，还利用傅立叶分析证明了差分方案的稳定性。最后，对接近平衡点的 Gierer-Meinhardt 模型进行了数值模拟，以探讨抑制剂降解率（用 E 表示）对图案形成的影响。随着 E 的变化，模型呈现出不同的图案结构，从而揭示了生物系统中组织变化与图案形成之间的关系。
{"title":"Analyzing the dynamic behavior of the Gierer–Meinhardt model using finite difference method","authors":"Jianping Lv, Hefang Jing","doi":"10.1063/5.0223717","DOIUrl":"https://doi.org/10.1063/5.0223717","url":null,"abstract":"In this paper, a numerical computation method for the Gierer–Meinhardt model in two-dimensional space diffusion with homogeneous Neumann boundary conditions, considering the interaction between activator and inhibitor substances, is proposed. First, a high-order compact finite difference scheme is constructed for the Gierer–Meinhardt model using the finite difference method. A fourth-order compact difference scheme is applied to the second-order spatial derivative terms, while the time derivative terms are discretized using Taylor series expansion and residual correction functions. Consequently, the difference scheme achieves fourth-order accuracy in space and second-order accuracy in time for the Gierer–Meinhardt model. In addition, the stability of the difference scheme is demonstrated using Fourier analysis. Finally, numerical simulations are conducted on the Gierer–Meinhardt model near its equilibrium point to explore the impact of the inhibitor degradation rate, denoted as E, on the pattern formation. The model exhibits distinct pattern structures with varying E, thereby revealing the relationship between tissue variability and pattern formation in biological systems.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"72 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141943490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kai Wang, Jiwei Zhao, Zhangyou Yang, Peixuan Zhu, Huan Lu, Bin Zheng
The emergence of 5G represents a pivotal step in merging mobile communication networks with the Industrial Internet of Things. Despite the numerous advantages of 5G, the presence of unknown obstacles can adversely affect user signals. Although mitigating signal pressures can be achieved by increasing base station density, it often involves bulky equipment and high costs. To address this, we propose a deep learning-based method for controlling tunable transmissive metasurfaces and validate their scattering control capabilities in the presence of obstacles. By constructing a network model to analyze the mapping relationship between metasurface arrays and far-field scattering, rapid control of scattering characteristics is achieved. AI-driven high-performance tunable metasurfaces exhibit vast potential applications in intelligent communication, offering a universal solution for intelligent control in complex signal environments.
{"title":"Programmable transmission metasurface scattering control under obstacles based on deep learning","authors":"Kai Wang, Jiwei Zhao, Zhangyou Yang, Peixuan Zhu, Huan Lu, Bin Zheng","doi":"10.1063/5.0217386","DOIUrl":"https://doi.org/10.1063/5.0217386","url":null,"abstract":"The emergence of 5G represents a pivotal step in merging mobile communication networks with the Industrial Internet of Things. Despite the numerous advantages of 5G, the presence of unknown obstacles can adversely affect user signals. Although mitigating signal pressures can be achieved by increasing base station density, it often involves bulky equipment and high costs. To address this, we propose a deep learning-based method for controlling tunable transmissive metasurfaces and validate their scattering control capabilities in the presence of obstacles. By constructing a network model to analyze the mapping relationship between metasurface arrays and far-field scattering, rapid control of scattering characteristics is achieved. AI-driven high-performance tunable metasurfaces exhibit vast potential applications in intelligent communication, offering a universal solution for intelligent control in complex signal environments.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"23 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141943487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dongjian Su, Qingwei An, Shao Xue, Hao Wang, Ruyi Tao
The impulse thruster exhibits the advantages of the simplistic structure and rapid response speed. It is often used for the attitude adjustment and orbit control of the aircraft and space vehicle. In order to study the internal ballistic variation law and the flow characteristics of the gunpowder gas, the interior working process of the L-type impulse thruster was investigated by the numerical simulation and experimental verification. First, an internal ballistic test was designed and conducted, and the change process of the thrust and pressure over time was measured, and the feasibility and rationality of the impulse thruster design were verified. Second, a three-dimensional internal ballistic model of the L-type impulse thruster including the ignition process was established. With the help of the dynamic mesh technology and secondary development capability of the user-defined function in the software Fluent, the coupling process of the propellant combustion and internal flow field change of the gunpowder gas was realized. The calculated results were in good agreement with the test data. Finally, the distribution of the pressure and velocity in the flow field was analyzed in detail, and the variation law of the thrust characteristics with the nozzle length and the expansion ratio was studied, which could provide the essential data for further optimization design research. The outcomes from this paper can offer technical means for advancing studies on the internal ballistic changing law of the L-type impulse thruster.
脉冲推进器具有结构简单、响应速度快等优点。它常用于飞机和空间飞行器的姿态调整和轨道控制。为了研究内弹道变化规律和火药气体的流动特性，通过数值模拟和实验验证，对 L 型脉冲推进器的内部工作过程进行了研究。首先，设计并进行了内弹道试验，测量了推力和压力随时间的变化过程，验证了脉冲推进器设计的可行性和合理性。其次，建立了包括点火过程在内的 L 型脉冲推进器三维内弹道模型。借助 Fluent 软件中的动态网格技术和用户自定义函数的二次开发能力，实现了推进剂燃烧与火药气体内部流场变化的耦合过程。计算结果与试验数据吻合良好。最后，详细分析了流场中压力和速度的分布，研究了推力特性随喷管长度和膨胀比的变化规律，为进一步优化设计研究提供了重要数据。本文的研究成果可为推进 L 型脉冲推进器内弹道变化规律的研究提供技术手段。
{"title":"Experiment and numerical investigation on internal ballistic characteristics of L-type impulse thruster","authors":"Dongjian Su, Qingwei An, Shao Xue, Hao Wang, Ruyi Tao","doi":"10.1063/5.0219940","DOIUrl":"https://doi.org/10.1063/5.0219940","url":null,"abstract":"The impulse thruster exhibits the advantages of the simplistic structure and rapid response speed. It is often used for the attitude adjustment and orbit control of the aircraft and space vehicle. In order to study the internal ballistic variation law and the flow characteristics of the gunpowder gas, the interior working process of the L-type impulse thruster was investigated by the numerical simulation and experimental verification. First, an internal ballistic test was designed and conducted, and the change process of the thrust and pressure over time was measured, and the feasibility and rationality of the impulse thruster design were verified. Second, a three-dimensional internal ballistic model of the L-type impulse thruster including the ignition process was established. With the help of the dynamic mesh technology and secondary development capability of the user-defined function in the software Fluent, the coupling process of the propellant combustion and internal flow field change of the gunpowder gas was realized. The calculated results were in good agreement with the test data. Finally, the distribution of the pressure and velocity in the flow field was analyzed in detail, and the variation law of the thrust characteristics with the nozzle length and the expansion ratio was studied, which could provide the essential data for further optimization design research. The outcomes from this paper can offer technical means for advancing studies on the internal ballistic changing law of the L-type impulse thruster.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"60 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141943492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to enhance the support capability of photovoltaic inverters for new energy microgrid systems, grid-forming control technology has attracted widespread attention, with Virtual Synchronous Generator (VSG) emerging as a research frontier. This paper integrates hybrid energy storage systems with photovoltaic generation to provide stable voltage support and power compensation for the system. In addition, leveraging the variability of the virtual parameters J and D in traditional VSGs, an adaptive grid-forming photovoltaic inverter control strategy based on fuzzy algorithm is proposed. Furthermore, to reduce the frequency deviation caused by load transients during islanding operation, an adaptive droop coefficient based on frequency power limits is introduced. Finally, simulations are conducted under grid-connected and islanded conditions to compare three control methods: fixed parameter control, traditional adaptive control, and the proposed adaptive with fuzzy control. The results demonstrate that integrating adaptive droop coefficients with fuzzy control can effectively improve the frequency stability and dynamic response capability of microgrids.
为增强光伏逆变器对新能源微电网系统的支持能力，并网控制技术受到广泛关注，其中虚拟同步发电机（VSG）成为研究前沿。本文将混合储能系统与光伏发电相结合，为系统提供稳定的电压支持和功率补偿。此外，利用传统 VSG 中虚拟参数 J 和 D 的可变性，提出了一种基于模糊算法的自适应并网光伏逆变器控制策略。此外，为了减少孤岛运行期间负载瞬变引起的频率偏差，还引入了基于频率功率限制的自适应下垂系数。最后，在并网和孤岛条件下进行了仿真，比较了三种控制方法：固定参数控制、传统自适应控制和所提出的自适应模糊控制。结果表明，将自适应下垂系数与模糊控制相结合可有效提高微电网的频率稳定性和动态响应能力。
{"title":"Adaptive grid-forming photovoltaic inverter control strategy based on fuzzy algorithm","authors":"Chenzhao Wang, Kan Cao, Pan Hu","doi":"10.1063/5.0223194","DOIUrl":"https://doi.org/10.1063/5.0223194","url":null,"abstract":"In order to enhance the support capability of photovoltaic inverters for new energy microgrid systems, grid-forming control technology has attracted widespread attention, with Virtual Synchronous Generator (VSG) emerging as a research frontier. This paper integrates hybrid energy storage systems with photovoltaic generation to provide stable voltage support and power compensation for the system. In addition, leveraging the variability of the virtual parameters J and D in traditional VSGs, an adaptive grid-forming photovoltaic inverter control strategy based on fuzzy algorithm is proposed. Furthermore, to reduce the frequency deviation caused by load transients during islanding operation, an adaptive droop coefficient based on frequency power limits is introduced. Finally, simulations are conducted under grid-connected and islanded conditions to compare three control methods: fixed parameter control, traditional adaptive control, and the proposed adaptive with fuzzy control. The results demonstrate that integrating adaptive droop coefficients with fuzzy control can effectively improve the frequency stability and dynamic response capability of microgrids.","PeriodicalId":7619,"journal":{"name":"AIP Advances","volume":"24 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141943489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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