scholarly journals EXPERIMENTAL STUDY OF STATIC CHARACTERISTICS ASYNCHRONOUS MACHINE IN DYNAMIC BRAKING MODE WITH INDUCTION RESISTANCE IN THE ROTOR WINDING

2021 ◽  
Vol 1 (38) ◽  
pp. 68-74
Author(s):  
S. Kolychev ◽  
А. Sianov
Keyword(s):  
Induction Machine ◽  
Current Frequency ◽  
Asynchronous Machine ◽  
Phase Switching ◽  
Asynchronous Machines ◽  
Braking Torque ◽  
Supply Current ◽  
Control Circuits ◽  
Rotor Winding ◽  
Dynamic Braking

The article discusses the results of a study of the static electromechanical characteristics of an asynchronous machine (AM) when prototypes of induction resistances (IR) with improved parameters are included in its rotor circuits. The dynamic braking (DB) of asynchronous machines, which is widespread in practice, provides for the dissipation of the kinetic energy of the rotating parts in the resistance boxes included in the rotor winding. In the process of stopping, to maintain a constant average braking torque AM, a bulky relay-contactor circuit for shunting rotor resistances is used. However, it is not possible to eliminate significant fluctuations in the electromagnetic torque in this way. To optimize the DB AM process, it is proposed to include a three-phase  IR in the rotor winding instead of resistance boxes, the value of which automatically decreases along with the rotor current frequency. This approach allows you to abandon contact equipment and ensure smooth braking of the machine with fluctuations in the electromagnetic moment in narrower limits. The known IR designs are designed for starting modes of induction motors with a wound rotor, but they cannot ensure the constancy of the torque on the AM shaft in the DB mode. Therefore, the purpose of the study is to develop and experimentally confirm the effectiveness of simple control circuits of an induction machine in the specified mode with improved contactless induction rheostats in the rotor. The paper presents a diagram of a pilot plant and a figure explaining the design features of the IR. The studies were carried out for an asynchronous machine of the MTB-412-8 type, equipped with a thyristor exciter and a tachogenerator. The three phases of the AM rotor included ICs connected by a "star". The experiments were carried out in the direction of obtaining the necessary braking characteristics of the AM by varying the switching circuit of the stator phases and the value of the current supplying them. The figures show the mechanical characteristics of AM, obtained in the process of studying the influence on them of three typical circuits for switching on the phases of the stator winding and two values ​​of the fixed supply current. The research results show that the desired form of the mentioned AM characteristics is achieved only when using the stator phase switching in a function of the rotor speed and a constant supply current value.

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 EXPERIMENTAL STUDY OF THE STATIC CHARACTERISTICS OF THE SYNCHRONOUS MACHINE IN THE MODE OF DYNAMIC BRAKING WITH INDUCTION RESISTANCE IN THE WINDING OF THE STATOR

2021 ◽  
Vol 2 (37) ◽  
pp. 22-27
Author(s):  
S. Kolychev ◽  
A. Sianov
Keyword(s):  
Mechanical Characteristics ◽  
Experimental Studies ◽  
Synchronous Machine ◽  
Stator Winding ◽  
Excitation Current ◽  
Current Frequency ◽  
Speed Sensor ◽  
Electromagnetic Moment ◽  
Braking Torque ◽  
Dynamic Braking

The article discusses the results of a study of the static electromechanical characteristics of a synchronous machine (SM) when prototypes of induction resistances (IR) with improved parameters are included in its stator circuits. Widespread in practice, dynamic braking (DB) of synchronous machines provides for the dissipation of the kinetic energy of the rotor in the resistance boxes included in the stator winding. In the process of stopping, to maintain the constancy of the average braking torque of the SM, a bulky relay-contactor shunt circuit for stator resistances is used. At low speeds, regulation of the excitation current of the SM or its forcing can also be applied. However, it is not possible to eliminate significant fluctuations in the electromagnetic moment in this way. To optimize the SM DB process, instead of resistance boxes, it was proposed to include a three-phase induction resistance in the stator winding, the value of which automatically decreases along with the stator current frequency. This approach allows you to drastically reduce the number of contact equipment and ensure smooth braking of the machine with electromagnetic moment fluctuations within narrow limits. Known IR designs are designed for asynchronous motors with a phase rotor and satisfy the requirements of the given quality factor of their starting characteristics, but cannot ensure the constancy of the torque on the SM shaft in the DB mode. Therefore, the objective of the work is to improve the design of the IR and obtain the necessary inhibitory mechanical characteristics of the SM using experimental studies. The work provides a pilot plant diagram and a drawing explaining the design features of the IR. The studies were performed for a synchronous machine, type МСА-72 / 4А, equipped with a thyristor exciter and a speed sensor. In three phases of the SM stator, IRs connected by a "star" were turned on. The experiments were carried out in the direction of obtaining the necessary braking characteristics of the SM by varying the design of the internal elements of the IR. The figures show the mechanical characteristics of the SM obtained in the process of studying the effect on them of the thickness of the inner steel rings and massive ferromagnetic disks at three values of the fixed excitation current. The research results show that the desired form of the mentioned characteristics of the SM is achieved only when using massive internal elements in the design of the IR. A separate figure shows the curves of changes in some values of the SM load, which will facilitate the development of methods for calculating the DB mode of the machine for the optimal design of the IR.

A Black-Box Model for Estimation of the Induction Machine Parameters Based on Stochastic Algorithms

2016 ◽  
pp. 528-552
Author(s):  
Julien Maitre ◽  
Sébastien Gaboury ◽  
Bruno Bouchard ◽  
Abdenour Bouzouane
Keyword(s):  
Manufacturing Industry ◽  
Induction Machine ◽  
Induction Machines ◽  
Black Box ◽  
Nsga Ii ◽  
Asynchronous Machine ◽  
Great Effectiveness ◽  
Asynchronous Machines ◽  
Roll To Roll ◽  
Single Objective

Knowledge on asynchronous machine parameters (resistances, inductances…) has become necessary for the manufacturing industry in the interest of optimizing performances in a production system (roll-to-roll processing, wind generator…). Indeed, accurate values of this machine allow improving control of the torque, speed and position, managing power consumption in the best way possible, and predicting induction machine failures with great effectiveness. In these regards, the authors of this paper propose a black-box modeling for a powerful identification of asynchronous machine parameters relying on stochastic research algorithms. The algorithms used for the estimation process are a single objective genetic algorithm, the well-known NSGA II and the new ?-NSGA III (multi-objective genetic algorithms). Results provided by those show that the best estimation of asynchronous machines parameters is given by ?-NSGA III. In addition, this outcome is confirmed by performing the identification process on three different induction machines.

A Black-Box Model for Estimation of the Induction Machine Parameters Based on Stochastic Algorithms

2015 ◽  
Vol 3 (3) ◽  
pp. 44-67
Author(s):  
Julien Maitre ◽  
Sébastien Gaboury ◽  
Bruno Bouchard ◽  
Abdenour Bouzouane
Keyword(s):  
Manufacturing Industry ◽  
Induction Machine ◽  
Induction Machines ◽  
Black Box ◽  
Stochastic Algorithms ◽  
Nsga Ii ◽  
Asynchronous Machine ◽  
Identification Process ◽  
Asynchronous Machines ◽  
Roll To Roll

Knowledge on asynchronous machine parameters (resistances, inductances…) has become necessary for the manufacturing industry in the interest of optimizing performances in a production system (roll-to-roll processing, wind generator…). Indeed, accurate values of this machine allow improving control of the torque, speed and position, managing power consumption in the best way possible, and predicting induction machine failures with great effectiveness. In these regards, the authors of this paper propose a black-box modeling for a powerful identification of asynchronous machine parameters relying on stochastic research algorithms. The algorithms used for the estimation process are a single objective genetic algorithm, the well-known NSGA II and the new ?-NSGA III (multi-objective genetic algorithms). Results provided by those show that the best estimation of asynchronous machines parameters is given by ?-NSGA III. In addition, this outcome is confirmed by performing the identification process on three different induction machines.

Design and Implementation of High-Speed Dual-Modulus

2011 ◽  
Vol 109 ◽  
pp. 271-275
Author(s):  
Jian Jun Song ◽  
Liu Sun ◽  
He Ming Zhang ◽  
Hui Yong Hu
Keyword(s):  
Power Supply ◽  
Dynamic Load ◽  
High Speed ◽  
Operating Speed ◽  
Switching Circuit ◽  
Switching Sequence ◽  
Phase Switching ◽  
Measurement Result ◽  
Design And Implementation ◽  
Supply Current

This paper presents a new enhanced phase switching 15/16 dual-modulus prescaler. One more divide-by-2 stage was employed in the design compare to the conventional phase switching architecture. Since the operating speed of phase switching circuit is obviously reduced. The inverse phase switching sequence was employed in this circuit to implement glitch-free phase switching. Further more, a dynamic load master-slave DFF was employed as the first divide-by-2 stage which can increase the operating frequency of prescaler. Measurement result shows, this dual-modulus prescaler can operate at 3GHz-200MHz with 2.8mA supply current at 1.8V power supply.

scholarly journals Improving the energy efficiency of electric drives for auxiliary units of traction rolling stock

2021 ◽  
Vol 2131 (4) ◽  
pp. 042085
Author(s):  
T S Titova ◽  
A M Evstaf’ev ◽  
A A Pugachev
Keyword(s):  
Energy Efficiency ◽  
Control Systems ◽  
Induction Motor ◽  
Induction Machine ◽  
Rolling Stock ◽  
Electric Drives ◽  
Operating Modes ◽  
Stator Current ◽  
Power Loss Reduction ◽  
Rotor Winding

Abstract The review of technical solutions and schematic characteristics of auxiliary drives for traction vehicles has shown that the most rational variant is an electric drive with an induction machine. Given the operating modes of the auxiliary drives and the share of their power consumption in the total locomotive power, the task of using scalar control systems for induction machines becomes relevant. Based on a mathematical model describing the dynamic energy conversion processes in the T-shape substitution circuit of an induction motor, taking into account stator steel losses and current displacement effects in the rotor winding and saturation along the main magnetic path, possibilities for reducing stator current have been investigated. In order to improve the energy efficiency of electric drives two variants of control system have been proposed. One based on search method of self-tuning to the stator current minimum and the other - on maintaining the power factor of induction motor at the level that ensures equality of active and reactive components of stator current. The hardware and software requirements for implementing control systems have been analysed. Modelling using Matlab has shown that both control systems work - power loss reduction can be as low as 50% and as high as 60% in certain modes.

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 Simplification of Mathematical Model of Double Fed Asynchronous Machine

2017 ◽  
Vol 1 (3) ◽  
Author(s):  
Rauf Ismail Mustafayev ◽  
Laman Hasan Hasanova
Keyword(s):  
Mathematical Model ◽  
Differential Equations ◽  
Power Systems ◽  
Voltage Drop ◽  
Renewable Energy Sources ◽  
Induction Machine ◽  
Sharp Change ◽  
Small Hydropower ◽  
Algebraic Differential Equations ◽  
Rotor Winding

Double Fed Asynchronous Machines in (DFAM) recent years have found wide application both as generators mainly in renewable energy sources (wind power, small hydropower), and as a motors embedded in various electric drives. In order to study the static and dynamic modes of operation of these machines as one of the most effective methods - the method of mathematical modeling is widely used. It was found that the algebraic-differential equations that make up the mathematical model of double fed induction machine are expediently represented in the d and q axes rotating with the rotor speed of the machine. Particularly this form allows relatively simple reproduction of control coordinates - amplitude and frequency converted to the rotor winding voltage. This mathematical model is based on the well-known Park equations for synchronous machines. It is proposed to simplify the algebraic-differential equations of the double-fed induction machine by reducing the transformer emf, the slip emf and the voltage drop on the stator winding of the machine. The results of calculations for the complete equations of the machine having the 6th order and on the simplified equations having the 4th order showed that the error in determining the regime parameters of the machine in steady-state conditions is in the range 0-7%, i.e. does not exceed 7 percent. The error in dynamic modes is also within acceptable limits. In the dynamics of the change in the regime parameters of DFIM with a sharp change in the disturbing influences slightly differ from each other, and with a sharp change in the control actions they make up 20-30%. This allows to recommend the proposed simplification for engineering calculations, especially when these machines operate in a group or in parallel with other machines and components of power systems. 

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.

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