scholarly journals RESEARCH SENSITIVITY OF THE ROTOR FLUX LINKAGE OBSERVER TO CHANGE PARAMETERS OF THE ASYNCHRONOUS MACHINE

2021 ◽  
Vol 1 (38) ◽  
pp. 57-67
Author(s):  
O. Klyuyev ◽  
O. Sadovoi ◽  
Y. Sokhina
Keyword(s):  
Steady State ◽  
Comparative Analysis ◽  
Mathematical Models ◽  
Control Object ◽  
Flux Linkage ◽  
Asynchronous Machine ◽  
Transmission Coefficients ◽  
Quality Of Control ◽  
Sensitivity Functions ◽  
Rotor Flux

When changing the parameters of the control object to ensure the required quality of control, the tuning parameters of the control system must be changed. Investigation of the sensitivity of mathematical models helps to choose the right technical parameters of the regulators. Therefore, there is an urgent scientific task, which consists in the development of mathematical models for calculating the steady-state values ​​of the sensitivity functions of the coordinates of non-linear systems to changes in their parameters. When synthesizing observers of the rotor flux linkage, it is indicated that the signal for evaluating the rotor flux linkage is most sensitive to a change in the active resistance of the rotor of an induction machine. However, the numerical values ​​of the transmission coefficients between the coordinates of the observer and the increments of the parameters of the asynchronous machine during its operation are not given, which does not allow a comparative analysis of the degree of influence of changes in certain parameters of the asynchronous machine on the signals of the observer of the flux linkage. The task is to find and compare the numerical values ​​of the functions of the sensitivity of the coordinates of the observer of the rotor flux linkage to the change in the parameters of the asynchronous machine by joint analytical solution of the static equations of the observer's sensitivity model and the state model of the asynchronous machine. In this work, analytical expressions are obtained for the steady-state values ​​of the sensitivity functions of the coordinates of such a nonlinear object as an observer of the rotor flux linkage to a change in the parameters of an asynchronous machine. A comparative analysis of the values ​​of the transmission coefficients between the parameters and coordinates in the system asynchronous machine — observer of the rotor flux linkage for its various rotation speeds is carried out. The proposed technique makes it possible to find the numerical values ​​of the transmission coefficients and to compare the degree of influence of various parameters of the asynchronous machine on the coordinates of the flux linkage observer. Transient processes obtained in the course of solving the equations of the dynamics of an asynchronous electric drive with an observer of flux linkage complement the results of analytical calculations. The performed calculations are aimed at increasing the depth of analysis of the properties of the flux link observer, which helps to reasonably choose the structure of feedbacks when synthesizing a closed observer.

scholarly journals Identification of heat exchangers according to the criterion of energy efficiency

2019 ◽  
Vol 276 ◽  
pp. 06022 ◽  
Author(s):  
Vladimir Velichkin ◽  
Vladimir Zavyalov
Keyword(s):  
Mathematical Model ◽  
Energy Efficiency ◽  
Mathematical Models ◽  
Control Systems ◽  
Heat Exchangers ◽  
Control Object ◽  
Control Action ◽  
Model Parameters ◽  
Quality Of Control ◽  
The Mathematical Model

The article presents the results of the analysis of the characteristics of heat exchangers methods for determining their mathematical models. The necessity of the availability of the mathematical model during the synthesis of automatic control systems with desired properties. The method of identification of the thermal control object by the testing control action is proposed. Since technological control objects always be an energy of interaction the energy efficiency criterion applied for automatic formation of the control action. Also the analytical self-adjusting system with a reference model in the form of an integrating link was applied. From the analytical researches it follows that the movement of the system along the optimal trajectory occurs at a constant speed and does not depend on the properties of the control object, and the optimal control depends on the properties of the control object, time, and technological requirements. It is shown that mathematical models of heat exchangers of the first and second orders are determined quite simply. The accuracy of the mathematical model parameters is limited only by the accuracy of the experimental data. The quality of control systems with desired properties, synthesized by experimental, and accurate models are virtually indistinguishable.

Steady-state mathematical models of convertors with biparametric regulation

1993 ◽  
Vol 140 (2) ◽  
pp. 105
Author(s):  
G. Carpinelli ◽  
F. Gagliardi ◽  
A. Sturchio ◽  
M. Russo
Keyword(s):  
Steady State ◽  
Mathematical Models

Electron drift caused by rf field gradient creates many plasma phenomena: An attempt to distinguish the cause and the effect

2011 ◽  
Vol 78 (2) ◽  
pp. 165-174 ◽  
Author(s):  
C. L. XAPLANTERIS ◽  
E. D. FILIPPAKI ◽  
I. S. MISTAKIDIS ◽  
L. C. XAPLANTERIS
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
Low Temperature ◽  
Mathematical Models ◽  
Field Gradient ◽  
Collision Frequency ◽  
The Other ◽  
Frequency Effect ◽  
Electron Drift ◽  
Plasma Parameters

AbstractMany experimental data along with their theoretical interpretations on the rf low-temperature cylindrical plasma have been issued until today. Our Laboratory has contributed to that research by publishing results and interpretative mathematical models. With the present paper, two issues are being examined; firstly, the estimation of electron drift caused by the rf field gradient, which is the initial reason for the plasma behaviour, and secondly, many new experimental results, especially the electron-neutral collision frequency effect on the other plasma parameters and quantities. Up till now, only the plasma steady state was taken into consideration when a theoretical elaboration was carried out, regardless of the cause and the effect. This indicates the plasma's complicated and chaotic configuration and the need to simplify the problem. In the present work, a classification about the causality of the phenomena is attempted; the rf field gradient electron drift is proved to be the initial cause.

scholarly journals Third harmonic current injection into highly saturated multi-phase machines

2017 ◽  
Vol 66 (1) ◽  
pp. 179-187
Author(s):  
Felix Klute ◽  
Torben Jonsky
Keyword(s):  
Current Injection ◽  
Saturation Level ◽  
Permanent Magnet Synchronous Machines ◽  
Flux Linkage ◽  
Harmonic Current ◽  
Fem Model ◽  
Third Harmonic ◽  
The Third ◽  
Rotor Flux ◽  
Multi Phase

Abstract One advantage of multi-phase machines is the possibility to use the third harmonic of the rotor flux for additional torque generation. This effect can be maximised for Permanent Magnet Synchronous Machines (PMSM) with a high third harmonic content in the magnet flux. This paper discusses the effects of third harmonic current injection (THCI) on a five-phase PMSM with a conventional magnet shape depending on saturation. The effects of THCI in five-phase machines are shown in a 2D FEM model in Ansys Maxwell verified by measurement results. The results of the FEM model are analytically analysed using the Park model. It is shown in simulation and measurement that the torque improvement by THCI increases significantly with the saturation level, as the amplitude of the third harmonic flux linkage increases with the saturation level but the phase shift of the rotor flux linkage has to be considered. This paper gives a detailed analysis of saturation mechanisms of PMSM, which can be used for optimizing the efficiency in operating points of high saturations, without using special magnet shapes.

scholarly journals BEHAVIOR OF THE PHARMACOKINETICS OF ENROFLOXACIN IN THE PHASE SPACE

2019 ◽  
Vol 7 (4) ◽  
pp. 288-293
Author(s):  
Miroslav Vasilev ◽  
Galya Shivacheva
Keyword(s):  
Comparative Analysis ◽  
Plasma Concentration ◽  
Phase Space ◽  
Differential Equations ◽  
Mathematical Models ◽  
Blood Plasma ◽  
Graphical Representation ◽  
Nonlinear Differential Equations ◽  
Qualitative Assessment ◽  
Second Order Differential Equations

Phase space is an approach for analysis of nonlinear differential equations. The graphical solutions that are obtained are convenient for qualitative assessment of the behavior of systems and processes. A comparative analysis of the pharmacokinetics of the antibiotic enrofloxacin administered intravenously in dogs and cats has been performed in the present study. The mathematical models that represent the change in blood plasma concentration of the two groups of animals are described by second-order differential equations. For the graphical representation of phase trajectories using the fluoroquinolone, the Mathcad program tools are used. The properties of the peculiar points are determined based on the received images.

scholarly journals Low Speed Estimation of Sensorless DTC Induction Motor Drive Using MRAS with Neuro Fuzzy Adaptive Controller

2018 ◽  
Vol 8 (5) ◽  
pp. 2691
Author(s):  
Mini R ◽  
Shabana Backer P. ◽  
B. Hariram Satheesh ◽  
Dinesh M. N
Keyword(s):  
Comparative Analysis ◽  
Induction Motor ◽  
Reactive Power ◽  
Adaptive Controller ◽  
Operating Conditions ◽  
Estimation Methods ◽  
Speed Estimation ◽  
Loop Model ◽  
Low Speed ◽  
Rotor Flux

<p>This paper presents a closed loop Model Reference Adaptive system (MRAS) observer with artificial intelligent Nuero fuzzy controller (NFC) as the adaptation technique to mitigate the low speed estimation issues and to improvise the performance of the Sensorless Direct Torque Controlled (DTC) Induction Motor Drives (IMD). Rotor flux MRAS and reactive power MRAS with NFC is explored and detailed analysis is carried out for low speed estimation. Comparative analysis between rotor flux MRAS and reactive power MRAS with PI as well as NFC as adaptive controller is performed and results are presented in this paper. The comparative analysis among these four speed estimation methods shows that reactive power MRAS with NFC as adaptation mechanism shows reduced speed estimation error and actual speed error at steady state operating conditions when the drive is subjected to low speed operation. Simulation carried out using MATLAB-Simulink software to validate the performance of the drive especially at low speeds with rated and variable load conditions.</p>

Sign in / Sign up

Export Citation Format

Share Document