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

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.

Author(s):  
Viktor Marus ◽  
Aleksandr Pugachev

The simulation results of 4 kW induction motor electric drive with scalar control system and different control topologies are presented. The perspective directions of further investigations on improving energy efficiency of electric drives with scalar control systems are highlighted.


2019 ◽  
Vol 8 (2S11) ◽  
pp. 2515-2521

Most customarily used motor in the industries are induction motor due to its low cost, robustness and less maintenance. The change in the existing framework is necessary in order to make the motor more efficient one. This paper cast enlightenment about the PLC based 3 phase multi-starter control induction motor with energy efficient single control system. In order to start the engine's operation by its own power, starters are used. Various starters are available to initiate the 3-phase induction motor namely Direct On-line, Star-delta, autotransformer and rotor impedance. The employment of this PLC based techniques helps to increase the energy efficiency of the motor .The employability of PLC in this system is to help in the growth of automation. The hardware and software results of the multi starter control using single control systems are analysed


Author(s):  
О. Klyuyev ◽  
A. Sadovoi ◽  
Y. Sokhina

In asynchronous electric drives with vector control on the rotor, it is necessary to calculate the value of the sine and cosine of the angle of rotation of the rotor relative to the stator to form control actions. When using angle sensors, complex structural tasks can arise — placement and reliable mounting of the sensor on the shaft and, accordingly, the task of the overall layout of the unit. For high-power machines, the tasks of developing and creating the design of the sensor itself arise. If serial rotor angular position sensors can be used, the task of placing and mounting the sensor is no less difficult. In these cases it is necessary to deduce the second end of a shaft from the case of the engine with contact rings that complicates its design. Therefore, the urgent need to create more reliable electric drives with vector control systems on the rotor is the synthesis of identifiers of the angle of rotation of the rotor. Identifiers are known whose calculation algorithms are based on determining the projections of the flow coupling vectors. In the work with the use of coordinate transducers of projections of stator or rotor current vectors and equations of electromagnetic circuits of an asynchronous machine, the synthesis and subsequent analysis of the properties of the rotor position angle identifier in vector control systems of dual power machines is performed. New equations of the identifier of flux couplings are received, its stability is investigated and on conditions of stability types of electric drives in which it is possible to apply the offered identifier are defined. The stability of the vector control system and sufficient identification accuracy when using the proposed equations and functions are confirmed by the method of mathematical modeling of the recommended electric drive systems in different operating modes.


Author(s):  
Mykhaylo Zagirnyak ◽  
Vita Ogar ◽  
Volodymyr Chenchevoi ◽  
Rostyslav Yatsiuk

Purpose This paper aims to work out a method for calculating losses in induction motor steel taking into account its saturation. Design/methodology/approach The theory of electric machines is applied during the analysis of induction motor equivalent circuits. The theory of Fourier series is used to determine the harmonic components of voltage, current and power. Instantaneous power theory and trigonometric transformations are used to solve algebraic and differential equations and their systems. The methods of approximation and interpolation are applied to obtain analytical expressions from the experimental data. Experimental research was carried out to verify the reliability of theoretical provisions and research results. Findings A method for assessing an induction machine steel as a function of the generalized electromotive force has been proposed. It allows taking into account higher harmonics of the current, which are caused by the presence of nonlinearity of an induction motor magnetic circuit. Practical implications The obtained results can be used in calculating the energy characteristics and operating modes of an induction motor, as well as in the construction of control systems. Originality/value A method for determining the losses in the stator steel of an induction motor, using a generalized electromotive force, has been proposed for the first time. It enables taking into account the currents flowing both in the stator circuit and in the rotor circuit.


Author(s):  
M.V. Pechenik ◽  
◽  
S.O. Burian ◽  
H.Y. Zemlianukhina ◽  
D.V. Rudniev ◽  
...  

Continuous transport systems, including rope conveyors designed to move people and goods, are subject to very strict safety and energy efficiency requirements. As a rule, suspended cableways in operation have an unregulated electric drive with a smooth start system. Among the ways to meet these requirements is the use of modern regulated electric drives. The electromechanical system with a vector-controlled asynchronous electric motor is considered in the work. Based on the obtained model, within the framework of the MATLAB / Simulink application package, an investigation of the dynamic characteristics of the cableway electric drive was carried out. An analysis of the nature of the distribution of dynamic error in terms of speed and energy losses depending on the load and speed of movement of the rope traction element of the transport system is given. The results presented in the article make it possible to choose rational electric drives for continuous transport systems with rope traction elements. References 5, figures 5, table.


2019 ◽  
Vol 8 (4) ◽  
pp. 500
Author(s):  
Oti Stephen Ejiofor ◽  
Ugwu Justin ◽  
Nnadi Damian Benneth ◽  
Ogbuefi Uche

In induction machines, the major concern is the temperature rise since it determines the maximum loading, in an attempt to avoid insula-tion deterioration and eventual loss of motor life. The effect of excessive heat in the motor stator and rotor windings and the stator mag-netic circuit can degrade the developed performance of the machine and also affect the motor loading and life span if not dispensed properly. This research work examines the thermal model for estimating the stator and rotor temperatures in cage induction motor. A state-variable model of the induction is used. The twin-axis stator reference frame is used to model the motor’s electrical behavior, because physical measurements are made in this reference frame. The thermal model is derived by considering the power dissipation, heat transfer and rate of temperature rise in the stator and rotor. The non-linear equations for electrical behavior of the motor and the thermal state equations for the stator and the rotor are solved using the MATLAB/Simulink blocks. This is to give room for the determination of the temperature of the stator and rotor windings inside the induction machine so as to evaluate the thermal stability of the induction motor and to check whether the insulation of the copper windings is sufficient at different operating conditions. It was found out from the thermal model analysis that the temperature of the stator and rotor windings increases due to stator and rotor copper losses which depend on the stator current. As the stator current is increased by increasing the torque, the temperature of each element is consequentially made to increase.  


2021 ◽  
Vol 330 ◽  
pp. 03009
Author(s):  
Viktor Ostrovlyanchik ◽  
Ivan Popolzin ◽  
Vasiliy Kubarev ◽  
Dmitriy Marshev ◽  
Qiang Qu

The electric drive of a hoist must ensure the formation of the required tachogram and the diagram of driving forces. The tachogram depends on the type of lifting vehicles. For hoist electric drives based on a wound-rotor induction motor, it is possible to use a frequency converter in the rotor circuit to control the motor speed and torque. When designing a converter, the problem arises of determining the operating modes of its bridges and the current direction between them. The article analyzes the operating modes of the hoisting motor in accordance with various sections of the tachogram of the unit and the connection between the mechanical and electrical coordinates of the drive. The analysis carried out in the work makes it possible to obtain and implement methods for determining the parameters of the frequency converter in the rotor circuit and developing an algorithm for controlling the converter bridges to ensure the required tachogram and driving force diagram.


2016 ◽  
Vol 40 (1) ◽  
pp. 279-286 ◽  
Author(s):  
Taner Goktas ◽  
Müslüm Arkan

This paper proposes a method for separation of broken rotor bar failures from low-frequency load torque oscillation in direct torque control (DTC) induction motor drives by using vq voltage and iq current components’ spectra. The effect of load torque oscillation should be considered in induction motor drives for reliable broken bar fault detection. Induction machine drivers are run in DTC mode to control its torque and speed. In practice, the presence of load torque fluctuation may sometimes cause false positive alarms on stator current spectrum. However, discerning of broken rotor bar failure from low-frequency load variation for DTC drives remains unexplored. Experimental results show that by using the proposed method broken rotor bar failure can be reliably detected in the presence of low-frequency load torque oscillation in DTC induction motor drives.


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