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.

Formation of Persistent Slip Band in Fatigued Copper Single Crystals

1982 ◽  
Vol 40 ◽  
pp. 470-471
Author(s):  
N. Y. Jin
Keyword(s):  
Volume Fraction ◽  
Fatigue Cracks ◽  
Wall Structure ◽  
Matrix Structure ◽  
Dislocation Dipole ◽  
Slip Bands ◽  
Persistent Slip Bands ◽  
The Matrix ◽  
Hard Shell ◽  
Copper Single Crystals

Localised plastic deformation in Persistent Slip Bands(PSBs) is a characteristic feature of fatigue in many materials. The dislocation structure in the PSBs contains regularly spaced dislocation dipole walls occupying a volume fraction of around 10%. The remainder of the specimen, the inactive "matrix", contains dislocation veins at a volume fraction of 50% or more. Walls and veins are both separated by regions in which the dislocation density is lower by some orders of magnitude. Since the PSBs offer favorable sites for the initiation of fatigue cracks, the formation of the PSB wall structure is of great interest. Winter has proposed that PSBs form as the result of a transformation of the matrix structure to a regular wall structure, and that the instability occurs among the broad dipoles near the center of a vein rather than in the hard shell surounding the vein as argued by Kulmann-Wilsdorf.

Modeling of Distributed Parameter Processes with Neural Networks

2014 ◽  
Vol 555 ◽  
pp. 530-540
Author(s):  
Honoriu Vălean ◽  
Mihail Abrudean ◽  
Mihaela Ligia Ungureşan ◽  
Iulia Clitan ◽  
Vlad Mureşan
Keyword(s):  
Neural Networks ◽  
Simulation Method ◽  
Distributed Parameter ◽  
Hearth Furnace ◽  
Original Solution ◽  
Steel Pipes ◽  
The Matrix ◽  
The Neural Networks ◽  
Derivatives Of ◽  
Seamless Steel

In this paper an original solution for the modeling of distributed parameter processes using neural networks is presented. The proposed method represents a particular alternative to a very accurate modeling-simulation method for this kind of processes, the method based on the matrix of partial derivatives of the state vector (Mpdx), associated with Taylor series. In order to compare the performances generated by the two methods, a distributed parameter thermal process associated to a rotary hearth furnace (R.H.F) from the technological flow of producing seamless steel pipes is considered. The main similarities and differences between the two methods are highlighted in the paper. The treated solution represents a premise for the usage of the neural networks in the automatic control of the distributed parameter processes domain.

Synthesis and Binding Affinity of Fluorine Containing NG-acyl and -sulfonyl BIBP3226 Derivatives: Ligands for the NPY Y1 Receptor

2016 ◽  
Vol 69 (7) ◽  
pp. 746
Author(s):  
Nigel A. Lengkeek ◽  
Maxine P. Roberts ◽  
Lei Zhang ◽  
I-Chieh J. Lee ◽  
Christopher J. R. Fookes ◽  
...  
Keyword(s):  
Binding Affinity ◽  
Emission Tomography ◽  
Tumour Imaging ◽  
Y1 Receptor ◽  
Important Amino Acid ◽  
Positron Emission ◽  
Npy Receptor ◽  
Almost All ◽  
Derivatives Of ◽  
Pet Radiopharmaceuticals

The neuropeptide Y (NPY) receptors are abundant in a range of tumours hence are a molecular target for tumour imaging and therapy, particularly by the use of radiolabelled molecules. NG-Substituted derivatives of the NPY receptor antagonist, BIBP3226, were prepared aiming to improve its current usability and to incorporate a positron-emitting radioisotope for development in positron emission tomography (PET) radiopharmaceuticals. The BIBP3226 derivatives were prepared in seven steps while retaining the critically important amino acid chirality. The acyl derivative retained acceptable ligand binding, however the sulfonyl derivatives lost almost all binding affinity.

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.

Sign in / Sign up

Export Citation Format

Share Document