NEW TOPOLOGY FOR SOFT STARTING AND SPEED REGULATION OF WOUND ROTOR ASYNCHRONOUS MACHINE CONTROLLED BY MICROPROCESSOR

2004 ◽  
Vol 13 (04) ◽  
pp. 929-939
Author(s):  
ARTHUR SHOIHET ◽  
MICHAEL A. SLONIM
Keyword(s):  
Theoretical Analysis ◽  
Theoretical Calculations ◽  
Feedback Regulation ◽  
Experimental Investigations ◽  
Asynchronous Machine ◽  
Pspice Simulations ◽  
Asynchronous Machines ◽  
Speed Regulation

A new topology for soft starting and speed regulation of wound rotor asynchronous machines is proposed. The feedback regulation is controlled by a microprocessor. A description of the microprocessor and its operation is presented. A theoretical analysis of the topology operation is carried out and verified by PSpice simulations. Experiments with 1.5 kW asynchronous machine are executed. Results of theoretical calculations, PSpice simulations and experiments are in good matching. The experimental investigations show that the proposed algorithm of soft starting is effective.

Controlling the Reactivity of C60: A Theoretical Analysis of the Electronic States Modulated by Substitutional Chemistry

1994 ◽  
Vol 359 ◽  
Author(s):  
S.-H. Wang ◽  
M. Kashani ◽  
S. Jansen
Keyword(s):  
High Temperature ◽  
Theoretical Analysis ◽  
High Temperature Superconductivity ◽  
Electronic States ◽  
Experimental Investigations ◽  
Cluster Stability ◽  
Simple Substitution ◽  
Doped Materials ◽  
Multiple Species

ABSTRACTThe availability of large amounts of Buckminsterfullerene has allowed a plethora of experimental investigations on fullerenes. The chemical and physical studies have focussed on synthesis, isomerism, magnetism, spectroscopy and high temperature superconductivity in doped materials. The chemical reactivities of fullerenes have been defined and most of the studies are dominated by C60 isomers. Some of the observed activities of fullerenes parlled those of alkeies. In our previous studies, the reactivity of the 6-6' bond with respect to eco- addition was described. Current studies have exploited the olefinic nature of the 6-6' bond and analyzed the effect of the addition on cluster stability and frontier character. In this work, we describe the mechanisms of simple substitution and analyze stability and orbital effects for the addition chemistry of C60 with multiple species. Evolving changes in orbital frontier character are analyzed with respect to site directed chemistry exhibited by C60.

scholarly journals To study the voltage stability limits of distributed generation using induction machine in distribution networks

2013 ◽  
Vol 16 (2) ◽  
pp. 43-53
Author(s):  
Chuong Trong Trinh ◽  
Anh Viet Truong ◽  
Tu Phan Vu
Keyword(s):  
Distributed Generation ◽  
Power Distribution ◽  
Power Flow ◽  
Voltage Stability ◽  
Reactive Power ◽  
Induction Machine ◽  
Distribution Networks ◽  
Distribution Grid ◽  
Asynchronous Machine ◽  
Asynchronous Machines

There are now a lot of distributed generation (DG) using asynchronous machines are connected to power distribution grid. These machines do not usually generate reactive power, even consume reactive power, so they generally affect the voltage stability of whole power grid, and can cause instability in itself it is no longer balanced by the torque to work. In this paper, we investigate the voltage stability problem of the asynchronous machine of wind turbines used in power distribution networks. From the static model of the asynchronous machine, this paper will apply the pragmatic criteria to analysis the voltage stability of the asynchronous machine based on the results of the power flow in power distribution network.

scholarly journals IMPROVEMENT OF MACHINE SAFETY DEVICES

2018 ◽  
Vol 58 (1) ◽  
pp. 17 ◽  
Author(s):  
Bohdan Matviiovych Hevko ◽  
Roman Bohdanovych Hevko ◽  
Oleksandra Mykolaivna Klendii ◽  
Mykola Vasyliovych Buriak ◽  
Yurii Volodymyrovych Dzyadykevych ◽  
...  
Keyword(s):  
Optimum Design ◽  
Test Bench ◽  
Theoretical Calculations ◽  
Experimental Investigations ◽  
Dynamic Parameters ◽  
Safety Devices ◽  
Basic Parameters ◽  
Machine Safety ◽  
Made In ◽  
New Machine

The article presents a development of new machine safety devices, which provide protection of operating elements from overload. Theoretical calculations have been made in order to determine the optimum design, kinematic and dynamic parameters of safety devices. A test bench has been developed and experimental investigations have been conducted in order to determine basic parameters of overload clutches.

Theoretical Analysis of a Reactive Reinforcement Method for Cylindrical Explosion-Containment Vessels

2014 ◽  
Vol 137 (1) ◽  
Author(s):  
Sui Yaguang ◽  
Zhang Dezhi ◽  
Tang Shiying ◽  
Li Jie ◽  
Lin Qizhao
Keyword(s):  
Shock Wave ◽  
Theoretical Analysis ◽  
Plastic Strain ◽  
Numerical Simulations ◽  
Circumferential Strain ◽  
Theoretical Calculations ◽  
Practical Application ◽  
Related Research ◽  
Explosion Loading ◽  
Approximate Expressions

A method for cylindrical explosion-containment vessels was presented, which used symmetrical implosion loading cooperating with the vessels to control the out-explosion loading, increasing the anti-explosion ability of explosion-containment vessels. In this study, theoretical analysis was developed first and response of cylindrical vessels loaded with implosion and out-explosion was discussed. Approximate expressions for final circumferential strain were obtained. Comparison between the theoretical calculations and the numerical simulations showed that the proposed method could effectively reduce the plastic strain of cylindrical explosion-containment vessels. The theoretical analysis introduced in this study can provide reference for related research. In addition, problems such as spall and defense of shock wave need to be solved before the presented method could be carried out in practical application.

scholarly journals Nanoplasmon–Semiconductor Hybrid for Interface Catalysis

Catalysts ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 429 ◽  
Author(s):  
Jingang Wang ◽  
Naixing Feng ◽  
Ying Sun ◽  
Xijiao Mu
Keyword(s):  
Optical Properties ◽  
Metal Oxide ◽  
Noble Metal ◽  
Hybrid System ◽  
Physical Mechanism ◽  
Theoretical Calculations ◽  
Experimental Investigations ◽  
Exciton Coupling ◽  
Surface Catalysis ◽  
Metal Metal

We firstly, in this review, introduce the optical properties of plasmonic metals, and then focus on introducing the unique optical properties of the noble metal–metal-oxide hybrid system by revealing the physical mechanism of plasmon–exciton interaction, which was confirmed by theoretical calculations and experimental investigations. With this noble metal–metal-oxide hybrid system, plasmonic nanostructure–semiconductor exciton coupling interactions for interface catalysis has been analyzed in detail. This review can provide a deeper understanding of the physical mechanism of exciton–plasmon interactions in surface catalysis reactions.

scholarly journals Non-covalent loading of ionic liquid-functionalized nanoparticles for bovine serum albumin: experiments and theoretical analysis

RSC Advances ◽  
2019 ◽  
Vol 9 (33) ◽  
pp. 19114-19120 ◽  
Author(s):  
Xingang Jia ◽  
Xiaoling Hu ◽  
Wenzhen Wang ◽  
Chunbao Du
Keyword(s):  
Ionic Liquid ◽  
Bovine Serum Albumin ◽  
Theoretical Analysis ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Theoretical Calculations ◽  
Covalent Binding ◽  
Functionalized Nanoparticles

Non-covalent binding between nanosilica and bovine serum albumin has been illustrated by experiments and theoretical calculations.

Boundary-layer velocity profiles in a swirling convergent flow field

1972 ◽  
Vol 52 (2) ◽  
pp. 357-367 ◽  
Author(s):  
T. M. Houlihan ◽  
D. J. Hornstra
Keyword(s):  
Boundary Layer ◽  
Flow Field ◽  
Swirling Flow ◽  
Theoretical Calculations ◽  
Experimental Investigations ◽  
Conical Nozzle ◽  
Flow Conditions ◽  
Boundary Layer Flows ◽  
Layer Velocity ◽  
Convergent Flow

Velocity distributions within the boundary layer of a swirling flow of incompressible fluid in a convergent conical nozzle have been investigated. Theoretical calculations with boundary conditions more appropriate to physically existent situations discounted the existence of 'super-velocities’ within the boundary layer. Parallel experimental investigations demonstrated an interdependence of core and boundary-layer flows which precluded the maintenance of the flow conditions required by the analysis.

scholarly journals Matrix structure of unified mathematical model of electric AC machines at control

2020 ◽  
Vol 209 ◽  
pp. 02023
Author(s):  
Rauf Mustafayev ◽  
Nurali Yusifbayli ◽  
Laman Hasanova
Keyword(s):  
Frequency Control ◽  
Synchronous Machine ◽  
Matrix Structure ◽  
Asynchronous Machine ◽  
Asynchronous Machines ◽  
Squirrel Cage ◽  
The Matrix ◽  
Almost All ◽  
Cage Rotor ◽  
Derivatives Of

The matrix structure of the equations of a generalized electric alternating current machine is proposed, which, based on the Parke equations, is written in the coordinate axes of the machines rotating with the rotor speed. In the matrix structure, the column matrices of the derivatives of the stator, excitation and rotor windings are equal to the product of diagonal matrices consisting of the machine parameters and the column matrices of the flux links themselves and the sum of the matrix columns of the control parameters which are the matrix columns of the stator voltage, excitation voltage, and rotor voltage. It is shown that the matrix structure of a generalized controlled AC machine is transformed into mathematical models of almost all encountered AC electric machines, namely, into a synchronous machine with two excitation windings - a longitudinal and a transverse one; in a synchronous machine with a longitudinal field winding (classic); in an asynchronous machine with a squirrel-cage rotor; into an asynchronous machine with a phase rotor. It has been shown that the matrix structure includes the controls of these machines both from the stator and from the rotor. On the stator side for synchronous machines, it is a frequency control that regulates both the amplitude and frequency of the applied voltage, and on the rotor side, a constant voltage control is supplied to the longitudinal and transverse windings. For asynchronous machines, the stator and rotor are frequency-controlled. The following are examples of frequency control of an asynchronous machine both from the stator and from the rotor.

scholarly journals Theoretical and Experimental Investigations of Large Stokes Shift Fluorophores Based on a Quinoline Scaffold

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2488
Author(s):  
Barbara Czaplińska ◽  
Katarzyna Malarz ◽  
Anna Mrozek-Wilczkiewicz ◽  
Aneta Slodek ◽  
Mateusz Korzec ◽  
...  
Keyword(s):  
Theoretical Calculations ◽  
Stokes Shift ◽  
Visible Region ◽  
Spectroscopic Properties ◽  
Cellular Membrane ◽  
Structural Features ◽  
Quantum Yields ◽  
Experimental Investigations ◽  
Case Scenario ◽  
Fluorescence Quantum Yields

A series of novel styrylquinolines with the benzylidene imine moiety were synthesized and spectroscopically characterized for their applicability in cellular staining. The spectroscopic study revealed absorption in the ultraviolet–visible region (360–380 nm) and emission that covered the blue-green range of the light (above 500 nm). The fluorescence quantum yields were also determined, which amounted to 0.079 in the best-case scenario. The structural features that are behind these values are also discussed. An analysis of the spectroscopic properties and the theoretical calculations indicated the charge-transfer character of an emission, which was additionally evaluated using the Lippert–Mataga equation. Changes in geometry in the ground and excited states, which had a significant influence on the emission process, are also discussed. Additionally, the capability of the newly synthesized compounds for cellular staining was also investigated. These small molecules could effectively penetrate through the cellular membrane. Analyses of the images that were obtained with several of the tested styrylquinolines indicated their accumulation in organelles such as the mitochondria and the endoplasmic reticulum.

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