检索结果-内蒙古大学图书馆

Integrated Digital Twins system for Oil Temperature Prediction of Power Transformer Based on Internet of Things

IEEE INTERNET OF THINGS JOURNAL 2025年第10期12卷 13746-13756页

作者： Lyu, Zhihan Wan, Zhibo Bian, Zengxu Liu, Yuqi Zhao, Wei Xidian Univ Sch Comp Sci & Technol Xian 710126 Shaanxi Peoples R China Qingdao Univ Coll Comp Sci & Technol Qingdao 266071 Peoples R China

Oil temperature is an important index to reflect the state of transformer and predict the fault and remaining useful life of transformer. However, the oil temperature of the transformer is affected by various factors, such as weather conditions, load changes, holidays, seasons, and so on. In order to predict oil temperature more accurately, this study proposes a VCEEMDAN data decomposition algorithm to extract the characteristics of oil temperature data. And we proposed a hybrid long-term series forecasting model of oil temperature based on VCEEMDAN, particle swarm optimization (PSO) and Informer. At the same time, the digital twins system of the manipulator is configured to assist personnel in maintenance when the oil temperature is abnormal. And the digital twins system of an oil-immersed power transformer to monitoring of transformer status. Finally, the above research is integrated into a digital twins system, including transformer condition monitoring, oil temperature prediction, and intelligent maintenance based on Internet of Things (IOT). The proposed prediction method was compared with the six existing models on three datasets. From the experimental results, the best index improvement is 77.97% higher than the second-best model. And the simulation system can provide a good reference for the practical application of the factory. This article presents a hybrid framework that achieves a accurate transformer oil temperature prediction.

关键词： Oils Power transformers Oil insulation Predictive models Temperature distribution Internet of Things Data models Accuracy Prediction algorithms Measurement Animation avatar digital twins industrial application Internet of Things (IOT) long-term series forecasting system modeling and simulation

来源：评论

学校读者我要写书评

暂无评论

Turbine inlet temperature effects on the start process of an expansion cycle liquid propellant rocket engine

引用

PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART G-JOURNAL OF AEROSPACE ENGINEERING 2023年第1期237卷 42-61页

作者： Eskandari, Mohammad Amin Karimi, Hassan Sarvari, Ali Naderi, Mahyar Khaje Nassir Al Deen Toosi Univ Technol Daneshgah BlvdEhsan St ExitEast Zeynoddin Highw Tehran 16579 Iran Sharif Univ Technol Tehran Iran

The main objective of this study is to investigate the effect of turbine inlet temperature on the transient phase of expansion cycle liquid propellant rocket engines during start. For this purpose, the non-linear differential mathematical model for 15 main components of the engine is derived, and the corresponding interaction between them is established. Afterward, the model is simulated using MATLAB Simulink, and 150 equations are solved with the Newton-Raphson method. The RL10 expansion cycle liquid propellant rocket engine is selected as a case study, and its dynamic behavior is simulated, and the results are compared with the experimental data. The simulation results showed that the present model for engine dynamic parameters, including thrust-chamber pressure, fuel, oxidizer mass flow rate, and turbo-pump speed, has less than 5% error compared to previous literatures. Using the prepared modeling software, the effect of turbine inlet temperature is studied on the engine start process. The obtained results demonstrated that inappropriate temperature profile during start transient might cause an engine malfunction while entering the nominal working regime.

关键词： Dynamic modeling liquid propellant rocket engine RL 10 transient analysis system modeling and simulation feed system start transients

来源：评论

学校读者我要写书评

暂无评论

modeling the effect of reusability on the performance of an existing LPRE

引用

ACTA ASTRONAUTICA 2021年 181卷 201-216页

作者： Naderi, Mahyar Karimi, Hasan Liang Guozhu KN Toosi Univ Technol Tehran Iran Beihang Univ Sch Astronaut Beijing 100083 Peoples R China

The objective of this research is to study the impact of main engine parameters on the performance of a reusable liquid propellant rocket engine (LPRE). For this purpose, after a brief review over the available reusable liquid propellant rocket engines (RLPREs), the Space Shuttle Main Engine (SSME) is selected as a case study and a modular simulation software has been developed for analyzing the steady-state performance of LPRE in MATLAB Simulink. The evolution path of SSME is studied in detail and considering the reusability, two approaches have been selected. In the first approach, the performance of an expendable version of SSME is simulated and compared with the reusable version. It is found that the SSME working at 109% or higher rated thrust level (RTL) is the most possible option for the expendable version of this engine. The simulation results show that the components of the expendable SSME would work at 3-12% higher operating condition and the engine thrust would be 4.76% higher. In the second approach, in order to decrease the loads on the engine components and to enhance the reusability capability, the throat of the combustion chamber is enlarged. The simulation results show that by 11% increase in the combustion chamber throat area, the average load on the engine's different components would decrease 5-17% but for the same level of thrust, the specific impulse would be 2.43 s less. It is believed that the obtained results can help the designers to have a quantitative overview of the effect of reusability on the LPRE and launch vehicle performance during the conceptual design phase.

关键词： Reusability Reusable liquid propellant rocket engine Space Shuttle Main Engine (SSME) Steady-state performance system modeling and simulation

来源：评论

学校读者我要写书评

暂无评论

Analysis and Application of Quasi-Static and Dynamic Phasor Calculus for Stability Assessment of Integrated Power Electric and Electronic systems

引用

IEEE TRANSACTIONS ON POWER systemS 2021年第3期36卷 1750-1760页

作者： Vega-Herrera, Jorge Rahmann, Claudia Andrea Valencia, Felipe Strunz, Kai Univ Antofagasta Elect Engn Dept Antofagasta Chile Univ Chile Elect Engn Dept Santiago Chile Univ Chile Elect Engn Santiago 8320000 Chile Tech Univ Berlin Elektrotech & Informat D-10587 Berlin Germany

Power system stability is widely assessed based on tools that rely on the representation of voltages and currents through quasi-static phasor calculus, implying that the network itself and the synchronous machine stators are modeled by algebraic equations. Accordingly, the associated fast transients are neglected, assuming those decay rapidly. However, with the increasing penetration of converter interfaced generation in power systems, the reliance on quasi-static phasor calculus is to be questioned. In this paper, the validity of quasi-static phasor calculus models is verified, and dynamic phasor calculus is considered as the alternative. A methodology to systematically compare quasi-static and dynamic phasor calculus is developed. It includes frequency response, modal, and sensitivity analyses. The methodology is applied to an IEEE test network considering penetrations of converter interfaced generation of up to 100%. The models are implemented in MATLAB. The H-infinity norm is proposed as an indicator to identify differences in the applicability of the models. The results show that the quasi-static phasor calculus is suitable for stability analysis only if low bandwidths of converter controls are given. Dynamic phasor calculus instead is suitable and applicable to generic stability studies of integrated power electric and electronic systems with high penetration of renewables.

关键词： Power system stability Transient analysis Stability analysis Mathematical model Power system dynamics Calculus Dynamic phasor quasi-static phasor system stability system modeling and simulation power electronics

来源：评论

学校读者我要写书评

暂无评论

NUMERICAL STUDY OF A WEIGHT-ADJUSTABLE BUOY FOR EFFICIENT WAVE ENERGY CONVERSION

NUMERICAL STUDY OF A WEIGHT-ADJUSTABLE BUOY FOR EFFICIENT WA...

引用

ASME/BATH Symposium on Fluid Power and Motion Control (FPMC)

作者： Tian, Hao Zhou, Boyang Zhang, Zengmeng Gong, Yongjun Dalian Maritime Univ Dalian Liaoning Peoples R China Key Lab Rescue & Salvage Engn Liaoning Prov Dalian Peoples R China

ISBN: (纸本)9780791885239

Heaving motion of ocean wave is a promising renewable energy source but challenging to capture with consistent conversion efficiencies. Main issue of the varying energy extraction efficiency of wave energy converters (WEC's) is primarily caused by the variation of incident wave frequency and amplitude. Traditional design of the WEC has to account for the extreme sea conditions, leaving the WEC to work at suboptimal regions for most of the time. Due to the loss characteristics of the fluid power components, the performance and efficiency drop rapidly when moved away from the optimal working condition. In order to improve the efficiency of WEC, the buoy needs to operate at maximum amplitude most of the time. To do so, a new buoy structure based on actively controlled fluid-air ratio is proposed. Contrast to the traditional buoy for WEC's, which has fixed density and weight, the proposed structure is capable of weight manipulation, resulting adjustable system natural frequency. HATLAB/Simulink simulation analysis is carried out to verify the feasibility of adjusting the gas-liquid ratio inside the buoy with a water hydraulic system. To resonate with the unknown incident wave, maximum power point tracking (MPPT) algorithm is proposed to control the buoy mass with trial steps for maximizing the resonating amplitude of the buoy. Initial simulation results have shown that the proposed system is capable of adjusting the natural frequency and the MPPT algorithm can increase the amplitude of the buoy motion.

关键词： Wave energy converters Maximum power point tracking system modeling and simulation Hydrodynamic modeling

来源：评论

学校读者我要写书评

暂无评论

A report on the Workshop Software Engineering for the Uncertain World 2020

A report on the Workshop Software Engineering for the Uncert...

引用

13th Innovations in Software Engineering Conference (ISEC)

作者： Kulkarni, Vinay TCS Res Res & Dev Pune Maharashtra India

ISBN: (纸本)9781450375948

Traditionally, software systems have been used to derive mechanical advantage through automation. The underlying assumptions being: objectives for the software system and the environment within which it will operate will remain largely unchanged;and the required information is available fully and with total certainty. Software development is then viewed as a refinement exercise from high-level human-understandable requirements to a deterministic machine-executable implementation. However, for a variety of reasons, these assumptions no longer hold. This calls for a new look at engineering software that's expected to deliver on the stated objectives in an everchanging environment characterized with partial information and inherent uncertainty. The workshop aims to brainstorm this emerging challenge of "Software Engineering for the Uncertain World".

关键词： Program specification and modeling languages system modeling and simulation modeling of uncertainty Probabilistic programming Learning-capable languages and software architectures Knowledge modeling and the integration of AI with Software Engineering Analysis and system verification in presence of uncertainty Adaptive systems

来源：评论

学校读者我要写书评

暂无评论

Static performance modeling and simulation of the staged combustion cycle LPREs

引用

AEROSPACE SCIENCE AND TECHNOLOGY 2019年第Mar.期86卷 30-46页

作者： Naderi, Mahyar Liang Guozhu Beihang Univ Sch Astronaut Beijing 100083 Peoples R China

The objective of the current research is to analyze the steady state performance of staged combustion cycle liquid propellant rocket engines (SCCLPREs) and to provide a comprehensive case study with all the required technical input data. For this purpose, using the modular concept, engine components are classified into 14 modules and a modeling and simulation platform for SCCLPRE integrated system simulation has been developed in MATLAB Simulink. Space shuttle main engine (SSME) has been selected as a case study, and its static performance has been studied. A total of 34 elements has been taken into account, and using 110 linear/non-linear equations the engine's system modular model has been established. Most of the equations are solved by direct substitution of the initial guesses and iteration through eleven nested iterative loops and a few nonlinear complex equations are solved by Newton-Raphson method. The SSME's throttled performance at four different throttling levels has been simulated, and the effect of throttling has been studied on engine major elements. It is found that by throttling, the pressure of preburners, combustion chamber and high-pressure turbopumps are influenced more than other elements. The simulation mean error at 109% rated thrust level (RTL), 100% RTL, 60% RTL and 50% RTL is 1.63%, 5.76%, 12.91% and 15.28% respectively. Comparing to the previous studies, the simulation accuracy has been enhanced 3% to 7%. The developed model is a basis for further research over SSME and other SCCLPRE. (C) 2018 Elsevier Masson SAS. All rights reserved.

关键词： Liquid propellant rocket engine Space Shuttle Main Engine (SSME) Steady state performance system modeling and simulation

来源：评论

学校读者我要写书评

暂无评论

Capacity Predictions for LFP-based Battery Electrode Formulation:A Data-Driven Approach

Capacity Predictions for LFP-based Battery Electrode Formula...

引用

第21届中国系统仿真技术及其应用学术年会

作者： Liu Kailong Tang Xiaopeng Zhang Yeshui Li Weihan WMG University of Warwick Department of Chemical and Biological Engineering The Hong Kong University of Science and Technology Guangzhou HKUST Fok Ying Tung Research Institute Department of Chemical Engineering University College London Faculty of Electrical Engineering and Information Technology RWTH Aachen University

Lithium-ion battery has become one popular power source in transportation electrification applications such as electric vehicles and hybrid electric *** energy conversion within the battery significantly relies on the properties of the electrode made of some material components interacting with one *** to the complicated process of electrode manufacturing,a reliable system simulation solution that could predict the manufactured battery electrode properties and quantify the importance weights of component variables of interest is crucial for the battery electrode *** present article scrutinizes the sensitivity analysis of material components on the capacities of LiFePO（LFP）-based battery electrode formulation via the regression *** be specific,a neighborhood component analysis-based data-driven approach is designed to well quantify the importance weights of five interested material component variables and effectively predict the resulted half-cell's *** results reveal that the proposed approach is able to accurately capture the underlying mappings between material components and three different capacities under 25/C,5 C,and 15 C ***,the most important component variables can be effectively discovered for model *** to the merits in terms of accuracy and generalization,the designed data-driven approach can not only conduct reliable capacity predictions but also guide the monitoring and optimization of material components for better battery electrode production.

关键词： Capacity prediction system modeling and simulation Data-driven approach Battery electrode production

来源：评论

学校读者我要写书评

暂无评论

Computation of flow diagrams of an acausal physical model and its application to hybrid power generation system design

引用

JOURNAL OF ADVANCED MECHANICAL DESIGN systemS AND MANUFACTURING 2018年第2期12卷

作者： Komoto, Hitoshi Kondoh, Shinsuke Masui, Keijiro Natl Inst Adv Ind Sci & Technol Namiki 1-2-1 Tsukuba Ibaraki 3058564 Japan

In the design process of complex engineered systems, design alternatives should be generated and verified systematically while realizing fast product development through the adaptation of the concepts of modular design and model-based design. Automation of the design process, or its synthesis process in particular, is crucial in increasing the productivity of the design process. Computational design synthesis (CDS) is a crucial technology for such automation, but CDS studied to date is not capable of generating design alternatives as combinations of various components, and of verifying their behavior considering physical phenomena in various domains On the assumption that system modeling and simulation techniques are used in context of modular design and model-based design of complex engineered systems, this study proposes a flow diagram automatically transformed from acausal physical model, which is used in these techniques. The flow diagram shows relations between sub-models in terms of energy-levels described with specific physical domains, and flow direction changes that characterize the system behavior. The paper shows that flow diagrams of a system model at different time intervals support generation of design alternatives considering its behavior characterized by these flows. The study illustrates the usage of the method with design improvement of a hybrid power generation system.

关键词： Computer-aided design Acausal modeling Computational design synthesis system modeling and simulation

来源：评论

学校读者我要写书评

暂无评论

Key Technologies in Lithium-ion Battery Management system of Electric Vehicles:Challenges and Recommendations

Key Technologies in Lithium-ion Battery Management System of...

引用

第19届中国系统仿真技术及其应用学术年会(19th CCSSTA 2018)

作者： Wang Yu-jie Chen Zong-hai Department of Automation University of Science and Technology of China Anhui Hefei 230027

The lithium-ion batteries,with their excellent performance,have been widely used in electric vehicles and hybrid electric *** an indispensable part of most electric vehicles and hybrid electric vehicles,the battery management system is designed to provide monitoring,diagnosis,control and protecting functions to enhance the operation of the battery *** and more attentions have been paid to lithium-ion battery management technology in recent *** present paper,through the analysis of literatures and in combination with our practical work,gives a brief introduction to the key technologies in battery management system such as lithium-ion battery performance modeling,theory and methods of estimation of the state-of-charge,state-of-energy,state-of-power and state-of-health,and other techniques for equalization,charging and fault diagnoses,in hopes of providing some inspirations to the research of the lithium-ion battery management.

关键词： Battery Management system system modeling and simulation State Estimation system Equalization

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：