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基于电推系统的GEO卫星转移轨道段可测控性优化设计 被引量:1
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作者 卢元申 朱峪 +3 位作者 王昊光 吴敏 张文 蒋桂忠 《测控技术》 2022年第7期98-104,共7页
基于电推系统的地球同步轨道(GEO)卫星需要利用霍尔推进器使其从地球同步转移轨道(GTO)推到GEO轨道,整个变轨时间段长达数月。在整个变轨过程中卫星具有姿态无法保持对地的特点,该特点将会减少卫星可测控时长。针对变轨段卫星姿态不确... 基于电推系统的地球同步轨道(GEO)卫星需要利用霍尔推进器使其从地球同步转移轨道(GTO)推到GEO轨道,整个变轨时间段长达数月。在整个变轨过程中卫星具有姿态无法保持对地的特点,该特点将会减少卫星可测控时长。针对变轨段卫星姿态不确定减少可测控时长的问题,提出了一种在已有的轨道和姿态条件下,使用梯度下降算法寻找测控天线最优布局的方法,目的是使卫星获得最长的总可测控覆盖时长以及对中继星最长的可测控时长。结果显示通过改动天线布局可以显著地提升对地以及对中继星可测控覆盖时长,同时也能提升转移轨道关键时段对中继星可测控覆盖时长。与为天线增加转台与控制系统这类传统方法相比,该方法可以在不增加成本和质量的前提下,在一定程度上改善了电推卫星的可见性时长,对全电推卫星测控有指导意义。 展开更多
关键词 电推系统 转移轨道 中继星测控 梯度下降法
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Analytical Study of Magnetohydrodynamic Propulsion Stability 被引量:3
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作者 M.Y. Abdollahzadeh Jamalabadi 《Journal of Marine Science and Application》 2014年第3期281-290,共10页
In this paper an analytical solution for the stability of the fully developed flow drive in a magneto-hydro-dynamic pump with pulsating transverse Eletro-magnetic fields is presented. To do this, a theoretical model o... In this paper an analytical solution for the stability of the fully developed flow drive in a magneto-hydro-dynamic pump with pulsating transverse Eletro-magnetic fields is presented. To do this, a theoretical model of the flow is developed and the analytical results are obtained for both the cylindrical and Cartesian configurations that are proper to use in the propulsion of marine vessels. The governing parabolic momentum PDEs are transformed into an ordinary differential equation using approximate velocity distribution. The numerical results are obtained and asymptotic analyses are built to discover the mathematical behavior of the solutions. The maximum velocity in a magneto-hydro-dynamic pump versus time for various values of the Stuart number, electro-magnetic interaction number, Reynolds number, aspect ratio, as well as the magnetic and electrical angular frequency and the shift of the phase angle is presented. Results show that for a high Stuart number there is a frequency limit for stability of the fluid flow in a certain direction of the flow. This stability frequency is dependent on the geometric parameters of a channel. 展开更多
关键词 stability frequency Stuart number transient flow Eletro-magnetic interaction number duct flow MHD propulsion
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Fuel Cell Technology for Propulsion and Power Generation of Ships: Feasibility Study on Ocean Research Vessel Sagarnidhi
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作者 Rajasekhar D Deepak Sankar P. S Ananthakrishna Narendrakumar D. 《Journal of Shipping and Ocean Engineering》 2015年第5期219-228,共10页
Rising fuel prices, increasing emission levels and impending environmental regulations made shipping industry to find an alternate for internal combustion engine in 21st century. Fuel cell is a sustainable, emerging t... Rising fuel prices, increasing emission levels and impending environmental regulations made shipping industry to find an alternate for internal combustion engine in 21st century. Fuel cell is a sustainable, emerging technology with negligible pollution. More significantly for a research ship, emission levels need to be substantially low to have quality measurements. A feasibility study is carried-out First time in the world, to drive an ice class multi-disciplinary ORV (Oceanography Research Vessel) Sagarnidbi, using hydrogen powered fuel cell. Sagamidhi is equipped with special equipments viz., Deep Sea winch, specially designed cranes for Launching and retrieval of ROV (Remotely Operable Vehicle), DSMC (Deep Sea Mining Crawler), Tsunami systems, manned/unmanned submersible and ACS (Autonomous Coring System) and other facilities that support research in Indian, International and Antarctic waters. Beside this, the propulsion system along with DP (Dynamic Positioning), centralized air conditioning and special equipments require enormous electrical power. The combustion of diesel oil in an engine, that coupled with an alternator generates electrical power required, along with NOx (Nitrous Oxides), SOx (Sulphur Oxides) and PM (Particulate Matter) emissions. Shipping industry is the fourth largest contributor to air pollution and carbon emissions, particularly in coastal areas, and the growth rate makes the problem even more critical. Stringent international air pollution regulation and increasing fuel price paves the way for an alternative "green emission technology". Various fuel cells were analyzed with different combination of fuel, electrolyte and electrodes. From the analysis, it has been found that SOFC (Solid Oxide Fuel Cell) is most suitable for the present scenario. A fuel cell designed with hydrogen as fuel, zirconium oxides stabilized with yttrium oxide as electrolyte and zirconium electrodes is used for 1.5 MW power output and 0.5 MW through regenerator. Volume required for storage of hydrogen is in line with volume of fuel and a high standard safety measures were taken using sensors. The present system saves 3000 MT/annum of diesel oil costing 3,000,000 USD approximately. 展开更多
关键词 Hydrogen air pollution SOX fuel cell REGENERATOR particulate matter.
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Application of Fuzzy Logic Controller for Development of Control Strategy in PHEV
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作者 Maged N.F. Nashed Said Wahsh +1 位作者 Hamed Galal Tarak Dakrory 《Computer Technology and Application》 2012年第1期1-7,共7页
In this paper, implantation of fuzzy logic controller for parallel hybrid electric vehicles (PHEV) is presented. In PHEV the required torque is generated by a combination of internal-combustion engine (ICE) and an... In this paper, implantation of fuzzy logic controller for parallel hybrid electric vehicles (PHEV) is presented. In PHEV the required torque is generated by a combination of internal-combustion engine (ICE) and an electric motor. The controller simulated using the SIMULINK/MATLAB package. The controller is designed based on the desired speed for driving and the state of speed error. In the other hand, performance of PHEV and ICE under different road cycle is given. The hardware setup is done for electric propulsion system; the system contains the induction motor, the three phase IGBT inverter with control circuit using microcontroller. The closed loop control system used a DC permanent generator whose output voltage is related to motor speed. Comparison between simulation and experimental results show accurate matching. 展开更多
关键词 Hybrid electric vehicles-induction motor internal combustion engine fuzzy logic control.
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Steady-State Performance Analysis of Brushless DC Propulsion Motor
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作者 Wei Xie Yu Lu Qi Wang 《Journal of Energy and Power Engineering》 2012年第9期1488-1492,共5页
The brushless DC motor can be used in the marine electric propulsion system for its excellent control characteristics and large thrust. In order to estimate the operating performances of the brushless DC motor for the... The brushless DC motor can be used in the marine electric propulsion system for its excellent control characteristics and large thrust. In order to estimate the operating performances of the brushless DC motor for the high-power shipping during the design stage, the steady-state analysis is as important as the dynamic analysis generally. A mathematical model of the brushless DC propulsion motor is established according to the state-space method for the dynamic and steady-state performance analysis. The state-space mathematical model is a set of linear differential equations, so the steady-state currents of the armature windings can be gained directly by the symmetrical boundary conditions and the eigenvalues of the system matrix. The steady-state simulation results are compared with the dynamic ones to validate the correctness of this eigenvector method. 展开更多
关键词 Brushless DC motor electric propulsion STEADY-STATE dynamic.
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A Study on an Airgap Control System in a Rotary-Small-Scaled Linear Induction Motor for Railway Vehicles
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作者 C.B. Park B.S. Lee 《Journal of Energy and Power Engineering》 2011年第12期1193-1198,共6页
In general, it is important to operate the; airgap length uniformly for improving the system efficiency independent of the flatness of the reaction plate in a railway propulsion system by a linear induction motor (LI... In general, it is important to operate the; airgap length uniformly for improving the system efficiency independent of the flatness of the reaction plate in a railway propulsion system by a linear induction motor (LIM). And it is possible to operate the LIM propulsion system efficiently without a change of the LIM capacity through the airgap length control on the sloped rail. So, in this research, the authors introduce an airgap control system to control the airgap length which depends on the flatness of the secondary reaction plate when the LIM is operated, and design a rotary small-scaled LIM and its airgap control system before manufacturing the real system. Then, the authors analyze some characteristics of the LIM (thrust and normal force, input current, efficiency and power factor), and through the LIM control modeling, the authors finally analyze an effect of the airgap-length control of the LIM by the airgap control system. 展开更多
关键词 Airgap control system linear induction motor PROPULSION railway vehicles.
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The Design and Realization of Personalized E-commerce Recommendation System
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作者 Guofeng ZHANG 《International Journal of Technology Management》 2015年第4期27-29,共3页
According to demand and function of the e-commerce recommendation system demand, this paper analyze and design e-commerce and personalized recommendation, design and complete different system functions in different sy... According to demand and function of the e-commerce recommendation system demand, this paper analyze and design e-commerce and personalized recommendation, design and complete different system functions in different system level; then design in detail system process from the front and back office systems, and in detail descript the key data in the database and several tables. Finally, the paper respectively tests several main modules of onstage system and the backstage system. The paper designed electronic commerce recommendation based on personalized recommendation system, it can complete the basic function of the electronic commerce system, also can be personalized commodity recommendation for different users, the user data information and the user' s shopping records. 展开更多
关键词 E-COMMERCE personalized recommendation recommendation system
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Adaptive Neuro-Fuzzy Inference System for Thermal Field Evaluation of Underground Cable System
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作者 Mamdooh S. AI-Saud 《Journal of Energy and Power Engineering》 2012年第10期1643-1650,共8页
The influence of thermal circuit parameters on a buried underground cable is investigated using an ANFIS (adaptive neuro-fuzzy inference system). Finite element solution of the heat conduction equation is used, comb... The influence of thermal circuit parameters on a buried underground cable is investigated using an ANFIS (adaptive neuro-fuzzy inference system). Finite element solution of the heat conduction equation is used, combined with artificial intelligence methods. The cable temperature depends on several parameters, such as the ambient temperature, the currents flowing through the conductor and the resistivity of the surrounding soil. In this paper, ANFIS is used to simulate the problem of the thermal field of underground cables under various parameters variation and climatic conditions. The developed model was trained using data generated from FEM (finite element method) for different configurations (training set) of the thermal field problem. After training, the system is tested for several scenarios, differing significantly from the training cases. It is shown that the proposed method is very time efficient and accurate in calculating the thermal fields compared to the relatively time consuming finite element method; thus ANFIS provides a potential computationally efficient and inexpensive predictive tool for more effective thermal design of underground cable systems. 展开更多
关键词 Underground cables AMPACITY thermal analysis finite element method adaptive neuro-fuzzy inference system.
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High-Performance of Power System Based upon ANFIS (Adaptive Neuro-Fuzzy Inference System) Controller 被引量:1
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作者 Yousif I. Al-Mashhadany 《Journal of Energy and Power Engineering》 2014年第4期729-734,共6页
The proposed controller incorporates FL (fuzzy logic) algorithm with ANN (artificial neural network). ANFIS replaces the conventional PI controller, tuning the fuzzy inference system with a hybrid learning algorit... The proposed controller incorporates FL (fuzzy logic) algorithm with ANN (artificial neural network). ANFIS replaces the conventional PI controller, tuning the fuzzy inference system with a hybrid learning algorithm. A tuning method is proposed for training of the neuro-fuzzy controller. The best rule base and the best training algorithm chosen produced high performance in the ANFIS controller. Simulation was done on Matlab Ver. 2010a. A case study was chopper-fed DC motor drive, in continuous and discrete modes. Satisfactory results show the ANFIS controller is able to control dynamic highly-nonlinear systems. Tuning it further improved the results. 展开更多
关键词 ANFIS controller power system high performance learning algorithm.
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Application of Neuro-Fuzzy Estimation for Rotor Flux in Speed Vector Control of Bearingless Induction Motor
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作者 Jose Soares Batista Lopes Luciano P. dos Santos +3 位作者 Jose A. de Paiva Valci F. Victor Andre L. Maitelli Andres O. Salazar 《Journal of Energy and Power Engineering》 2015年第2期192-198,共7页
The main requirement of a vector controller is knowing the magnitude and position of the rotating flow in the rotor. This feature permits to use either flow sensors or flow estimators. The solution chosen was the esti... The main requirement of a vector controller is knowing the magnitude and position of the rotating flow in the rotor. This feature permits to use either flow sensors or flow estimators. The solution chosen was the estimation of rotor flux with the hybrid neuro-fuzzy system. The motor characteristics are: 3.75 kW (5 HP), two pole-pair, operate at 60 Hz and air-gap length 0.2 mm. The ANFIS (adaptive neuro-fuzzy inference system) was used to tune the membership functions in fuzzy system. The hybrid estimator aims at compensating possible parametric variations of the machine caused by agents, such as temperature or nucleus saturation. The simulated results have shown good performance. 展开更多
关键词 Hybrid systems rotor flux ESTIMATION speed control ANFIS.
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