scholarly journals Investigation of an asynchronous electric drive with frequency control

2021 ◽  
Vol 3 (45) ◽  
pp. 3-3
Author(s):  
Alexander Saakian ◽  
◽  

Currently, there are quite a large number of various scientific papers on the creation of a controlled asynchronous motor and optimization of its modes, and the availability of acceptable results for practical implementation, but there is still no single generally accepted approach to solving the problem. In this regard, the issue of synthesis of scalar control systems that provide the minimum value of a particular energy efficiency criterion is relevant. In this paper, we consider the obtained mathematical model of an asynchronous motor (AD), which differs from the known ones in that the parameters of the substitution circuit are expressed in terms of the stator and rotor conductivities. The energy characteristics of the AD in the sliding function are obtained, which make it possible to determine the dependences of the active and reactive components of the AD current and the possibility of their redistribution within the nominal value of the AD phase current. The principle of optimal frequency-current control of AD is formulated, which differs from the known ones in that, as an energy efficiency indicator, the value of the maximum energy efficiency of AD is used, expressed as the ratio of the active resistance of the rotor circuit to the total conductivity of the AD phase. Keywords: ASYNCHRONOUS MOTOR, ASYNCHRONOUS ELECTRIC DRIVE, EFFICIENCY, POWER FACTOR, ENERGY EFFICIENCY, CIRCUIT CONDUCTIVITY, REPLACEMENT CIRCUIT, SLIP

2021 ◽  
Vol 2061 (1) ◽  
pp. 012053
Author(s):  
D A Vasilyev ◽  
R I Gavrilov ◽  
L A Panteleeva

Abstract Currently, there are quite a large number of various scientific papers on the creation of a controlled asynchronous engine and the optimization of its modes, and the availability of acceptable results for practical implementation, but there is still no single generally accepted approach to solving the problem. In this regard, the issue of synthesis of scalar control systems that provide the minimum value of one or another criterion of energy efficiency is relevant. In this paper, we consider the obtained mathematical model of an asynchronous engine (AE), which differs from the known ones in that the parameters of the substitution scheme are expressed in terms of the stator and rotor conductivities. The energy characteristics of the AE in the sliding function are obtained, which make it possible to determine the dependences of the active and reactive components of the AE current and the possibility of their redistribution within the nominal value of the AE phase current. The principle of optimal frequency-current control of AE is formulated, which differs from the known ones in that, as an energy efficiency indicator, the value of the maximum energy efficiency of AE is used, expressed as the ratio of the active resistance of the rotor circuit to the total conductivity of the AE phase.


Author(s):  
I. V. Shestakov ◽  
N. R. Safin

The paper introduces the results of mathematical simulation of the operating modes of an asynchronous motor when powered by a sinusoidal voltage source and a width-modulated voltage pulse source. The study shows the possibilities of increasing the energy efficiency of an asynchronous electric drive. Findings of research show the feasibility of studying the switching of the motor power source from a pulse width-modulated voltage to a sinusoidal voltage source in the nominal operating mode in order to increase the energy efficiency of the electric drive


Author(s):  
V. N. Meshcheryakov ◽  
D. S. Sibirtsev ◽  
S. Valtchev ◽  
E. I. Gracheva

THE PURPOSE. In controlled AC drives used on continuous-action mechanisms, which include conveyors, conveyors, cranes, the most widespread are asynchronous motors with a phase rotor, controlled mainly along the rotor circuit using various regulators with low energy efficiency. To improve the energy efficiency of an electric drive based on ADFR, it is proposed to develop a control system that combines the principles of frequency control of the motor along the stator circuit and powering the rotor circuit with constant voltage, which allows the electric drive to be considered synchronized. METHODS. The presence of a DC link in the frequency converter makes it possible in principle to connect the rotor winding in series to this link. However, in order to ensure the frequency principle of regulating the output characteristics of the electric drive, it will be necessary to regulate the rectified current at the input of the inverter and, accordingly, in the rotor windings, which will require a significant change in the standard control system of the frequency converter. The use of an additional adjustable switch in the DC link is proposed. RESULTS. The study of the proposed non-standard control system for a frequency asynchronous synchronized electric drive was carried out by the method of simulation modeling in the Matlab Simulink software package. CONCLUSION. A control system for a frequency asynchronous synchronized electric drive has been developed and investigated on a computer model. A correction system is proposed that allows maintaining a constant value of the load angle in the starting mode. The scalar system of relay frequency control of the electric drive is supplemented with vector correction of the variables, which makes it possible to continuously provide the necessary mutual orientation of the stator current vectors and the rotor flux linkage.


Author(s):  
V. N. Meshcheryakov ◽  
D. S. Sibirtsev ◽  
S. Valtchev ◽  
E. I. Gracheva

THE PURPOSE. In controlled AC drives used on continuous-action mechanisms, which include conveyors, conveyors, cranes, the most widespread are asynchronous motors with a phase rotor, controlled mainly along the rotor circuit using various regulators with low energy efficiency. To improve the energy efficiency of an electric drive based on ADFR, it is proposed to develop a control system that combines the principles of frequency control of the motor along the stator circuit and powering the rotor circuit with constant voltage, which allows the electric drive to be considered synchronized. METHODS. The presence of a DC link in the frequency converter makes it possible in principle to connect the rotor winding in series to this link. However, in order to ensure the frequency principle of regulating the output characteristics of the electric drive, it will be necessary to regulate the rectified current at the input of the inverter and, accordingly, in the rotor windings, which will require a significant change in the standard control system of the frequency converter. The use of an additional adjustable switch in the DC link is proposed. RESULTS. The study of the proposed non-standard control system for a frequency asynchronous synchronized electric drive was carried out by the method of simulation modeling in the Matlab Simulink software package. CONCLUSION. A control system for a frequency asynchronous synchronized electric drive has been developed and investigated on a computer model. A correction system is proposed that allows maintaining a constant value of the load angle in the starting mode. The scalar system of relay frequency control of the electric drive is supplemented with vector correction of the variables, which makes it possible to continuously provide the necessary mutual orientation of the stator current vectors and the rotor flux linkage.


2020 ◽  
Vol 178 ◽  
pp. 01021 ◽  
Author(s):  
Victor Meshcheryakov ◽  
Dmitry Sibirtsev ◽  
Ekaterina Mikhailova

At the end of the last century asynchronous motors with a phase rotor were most widely used among adjustable-speed AC drives. They were used for conveyors, transporters, cranes. That was due to the relative simplicity to adjust the motor speed by acting on the rotor chain. The introduction of a frequency control method in such drives is now complicated by the fact that most frequency converters are designed to be used in drives with a cage asynchronous motor. Shorting of a phase winding leads to highly increased losses during acceleration and motor speed control. If the stator winding of a wound-rotor asynchronous motor is connected to a frequency converter and the rotor winding is connected to a DC link of this converter, the motor will have properties of a synchronous one. The electric drive is able to work in a wide range, while motor characteristics are absolutely rigid. The implementation of such control method is presented in this article. The control system operation has been tested with simulation in the Matlab Simulink software pack. The obtained results are defined as follows.


Author(s):  
Evgeny Eshchin ◽  

Variants of constructing control systems with a lagging argument for the positioning problem of an asyn-chronous electric motor (IM) and the problem of energy-saving AM control are considered. Variants of control of an asynchronous electric drive with IM on the basis of predicting its state are considered. The analytical de-sign of the predictor (ADP) is an asynchronous motor control algorithm based on the mathematical theory of optimal control (L.S. Pontryagin's maximum principle). The control algorithm (ADP) ensures the achievement of the minimum value of the target functional, which (functional), in contrast to the structure of the classical pre-dictive control system (Model Predictive Control - MPC), is clearly not part of the ADP. Calculations of the movements of an electric drive with an IM in the control modes of its state, taking into account delays along the channels for assessing its state and control, as well as using predictors, are given. The effectiveness of the in-troduction of predictors to improve the stability and quality of control of an electric drive with an IM has been established.


Author(s):  
Sergey Grigoryevich Cherniy ◽  
Aleksandr Sergeevich Sobolev ◽  
Pavel Andreevich Erofeev

The paper describes a variable frequency drive which consists of two elements: an electric drive (synchronous or asynchronous electric drives, that is, drives powered by alternating current are used in capacity of it), and a frequency converter able to control the amplitude and frequency of the voltage supplied to the drive. It becomes possible to control the speed of rotation of the electric motor and the torque on its shaft. The most optimal energy efficiency when using compressor units is achieved under the operating mode when its average daily load factor makes at least 85%. Under the mentioned operating mode fluctuations during the compressed air consumption will be minimal, and the most stable operation of the compressor at its rated nominal power is ensured. In practice, no more than 15% of all the industrial compressors are operated in such operating mode. For 85% of the compressor units the question of improving energy efficiency by regulating its capacity remains open. The method of capacity regulation by using a frequency converter is currently the most optimal and perfect, because adjusting the parameters of the electric drive in this way, the most accurate regulation of the compressed air pressure is provided, which allows reducing the energy consumption in the compressed air injection process, as well as extending the service life of the equipment used. There has been considered a device with frequency control of a compressor unit, debugging of which was carried out on the basis of a mathematical model, which allows choosing the most optimal parameters for frequency control of an electric drive of a compressor unit in order to increase energy efficiency. The analysis of all the advantages and disadvantages of frequency regulation is being carried out, as well as a comparative analysis for selecting the optimal frequency converter in terms of the import substitution


Author(s):  
I.M. Kotsur ◽  
A.V. Hurazda ◽  
B.A. Dolia ◽  
L.E. Shestov

Purpose. Improving the efficiency and energy performance of an asynchronous electric drive for stationary fan’s units of the main ventilation line of mines. Methodology. The research was carried out using the methods of the theory of electrical circuits, mathematical physics, simulation, interpolation and approximation Findings. The research of electromagnetic and energy processes in the asynchronous electric drive system with pulse control at a fan load, taking into account the variable aerodynamic parameters of the main ventilation line of mines. An electric drive system is able to respond with high accuracy and reliability to changes in the aerodynamic parameters of the main ventilation line of mines has been proven. This will also increase the power factor of the electric drive at a fan load up 0.8 to 0.93 p.u., and the efficiency up 92.5% to 94.5%, when regulating in the range of the operating slip of the rotor of the drive fan motor = 0.5 ÷, which, respectively, is on average up 0,25% to 40 higher in comparison with systems of an unregulated electric drive. Recommendations has been developed for the design and rational selection of the rated fan capacity for the main ventilation line to advance the best energy efficiency level of the electric drive. Originality. The research of electro-mechanical, electro-energy power and aerodynamic processes in the dynamic modes of the fan electric drive was carried out. The fan-loaded "induction motor-converter" system has been proven to be self-regulating. It is able to respond with high accuracy and reliability even at low switching frequencies of the power chopper to any changes of the aerodynamic parameters of the main ventilation line of mines. Practical value. Recommendations has been developed for the design and rational selection of the rated fan capacity for the main ventilation line to advance the best energy efficiency level of the electric drive.


2015 ◽  
Vol 2015 (4) ◽  
pp. 91-99 ◽  
Author(s):  
Татьяна Сморудова ◽  
Tatyana Smorudova ◽  
Дмитрий Кочевинов ◽  
Dmitriy Kochevinov ◽  
Галина Федяева ◽  
...  

This paper reports the variant for the advancement of the functional circuit and algorithms to control a bridge crane travels with the correction of misalignment and transverse displacement on basis of the use of new systems of a nonsynchronous electric drive with frequency control. It is offered to use a simple and reliable frequency – current with an autonomous inverter of current and a relayvector algorithm of control. A functional circuit of the system of frequen-cy-current control for the mechanism of a bridge crane travel with the correction of misalignment and transverse displacement. To analyze a crane position there are used differential values obtained by means of the indication difference in contactless sensors measuring a distance from the preset crane points to rails on the opposite supports. The procedure for the computation of control system parameters is stated. For the check of created functional circuits and algorithms of control there is used a complex electromechanical computer model of a bridge crane with a high degree of detailed elaboration (a virtual prototype of a bridge crane). The modeling results of are shown. The shown frequency – current system of control with the correction of misalignment and transverse displacement allows the decrease of threshold differential valuations and the increase of speed and accuracy of regulation


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