Characteristics Of Asynchronous Motor Research Articles

Topological optimization of the design of a permanent magnet synchronous motor using a genetic algorithm

The operating efficiency of a synchronous motor strongly depends on the design of its component parts, including the arrangement of materials (topology) of the rotor. An important element of the rotor, and at the same time the most expensive, are permanent magnets made of NdFeB material. Topological optimization allows you to reduce the volume of permanent magnets, which will reduce the price of the motor, or switch to cheaper materials, for example, ferrite, while maintaining performance characteristics. A genetic algorithm is used as a search method. And an important feature is that topological optimization is complex; not only electromagnetic parameters are checked, but also the thermal and strength characteristics of a synchronous motor. This test allows us to obtain designs that can be manufactured in practice. The article discusses the developed method of complex topological optimization using a genetic algorithm, optimization results and methods for testing the resulting structures. Optimization allows you to reduce the volume of NdFeB magnets by 2232%, which reduces the cost of the motor by 14–21%, or switch to ferrite magnets, which reduces the cost by 24–33%, while the torque value changes within 2%, which indicates about conservation of torque.

MATHEMATICAL MODELING OF THE SYNCHRONOUS MAIN DRIVE MOTOR OF THE HOT-ROLLED MILL 2800

This article discusses the calculation of the parameters of the mathematical model and the dynamic characteristics of a synchronous motor for the main drive of a hot-rolled mill 2800.

Study of the Parameters of the Substitution Scheme and Calculation of Mechanical Characteristics of Asynchronous Motors of the AIR Series Taking into Account the Skin Effect in the Rotor Winding

Studies of catalog data and parameters of substitution schemes for asynchronous motors of the air series with a short-circuited rotor have been performed in order to obtain general laws and analytical expressions depending on the engine power. In the Mathcad computer-aided design system, 32 engines were studied, and machines with a synchronous speed of 1500 rpm were taken as the main ones. Catalog data in the reference literature, according to manufacturers and other sources, differ significantly from each other, and so analytical expressions that reflect their average values are needed. General regularities and analytical expressions for determining the necessary parameters are obtained. An approximate method for calculating mechanical characteristics is proposed that takes into account the skin effect and current displacement in the rotor winding, which allows obtaining mechanical characteristics with an increased starting torque.

Mathematical model to take into account the influence of saturation of the magnetic circuit on the starting characteristics of a synchronous motor

The results of the development of a mathematical model of a synchronous motor and a study of the influence of the degree of saturation of the magnetic circuit on the transient processes of direct start-up are presented. It is noted that the existing methods of research and calculation of transient processes of synchronous machines are based on the application of the superposition (superposition) method, which excludes their use in nonlinear systems.

Mathematical Simulation of Modes and Characteristics of Asynchronous Motors under Asymmetrical Power Supply

Mathematical Simulation of Modes and Characteristics of Asynchronous Motors under Asymmetrical Power Supply

Virtual Synchronous Motor Based-Control of a Three-Phase Electric Vehicle Off-Board Charger for Providing Fast-Charging Service

This study introduces a three-phase virtual synchronous motor (VSM) control and its possible application for providing fast-charging service from off-board chargers of electric vehicles (EVs). The main circuit of the off-board charger consists of a three-phase voltage source PWM rectifier (VSR) and a resonant LLC zero-voltage-switching converter. In the proposed control approach, VSM-controlled pre-stage VSR emulates the external characteristics of a synchronous motor (SM), simultaneously, droop control based on charging mode in the VSM can satisfy the demand of the EVs constant-current fast-charging; The post-stage DC–DC converter is responsible for stabilizing the DC bus voltage. The feature of this control strategy is that VSM and fast charging control are implemented by the pre-stage converter, which has better coordination. In the MATLAB, the equivalent synchronous grid of the distribution network supplies to the power battery through the off-board charger, and the effectiveness of the presented control is demonstrated by typical working conditions.

An experimental study of the operating characteristics of an asynchronous motor with pulse supply

The fundamentals of design procedure of performance data of controlled asynchronous motors (AMs) supplied with pulse voltage are stated in this article. The proposed model is based on a L-shaped equivalent circuit for each of harmonics, on which the curve of applied to a phase voltage is displayed. It is proposed to find the increase of magnetic iron loss caused by hysteresis in proportion to the peak value of the pulse voltage. The influence of PWM voltage on magnetic hysteresis loss is determined by using a coefficient depending on the effective values of fundamental and higher harmonics of the EMF and voltages, as well as the coefficient taking into account the increase of electrical resistance of iron due to the skin effect. In a similar way, it is proposed to take into account magnetic losses in the rotor that are occasioned only by the influence of higher harmonics. It is proposed to determine the increase of resistance and decrease of the inductance of short-circuited rotor of the influence of currents of higher harmonics by the well-known Interelectro methodology. The resulting values of consumption current, power factor, effective power, and consumption power of an asynchronous motor with pulse voltage are calculated taking into account the total effect of currents and voltages of fundamental and higher harmonics. Based on the methodology that we have laid out, a program was written and modeling was carried out of the operational characteristics of an asynchronous motor with a power of 180 W supplied by a PWM inverter with a fundamental frequency of 50 Hz. In addition, the harmonic composition of pulse voltage was obtained by processing the oscillograms taken from phase windings of the motor supplied by the frequency converter. To experimentally check of the proposed model, an experimental plant for loading the asynchronous motor was assembled and the operational characteristics of asynchronous motor with the fundamental harmonic of 50 Hz were determined. The experimental results showed satisfactory convergence with the calculated results that makes it possible to recommend the proposed methodology to evaluate the energy indices of frequencycontrolled asynchronous motors.

The investigation of complex influence of individual electricity quality parameters for the technical characteristics of asynchronous motor

В статті розглядається сумісний вплив несиметрії та несинусоїдальності напруг на технічні характеристики асинхронного двигуна. Отримані відповідні залежності при різних коефіцієнтах навантаження

Characteristics of an asynchronous motor with side wedging of a rotor bar

Calculation results of the static and dynamic characteristics of asynchronous motors with a squirrel-cage rotor at different radial arrangements and dimensions of the rotor’s slot side wedge are presented, and recommendations for the arrangement and choice of side wedge dimensions are given.

Wavelet Transform for Starting Characteristics of Three-Phase Cage Asynchronous Motor

In electric machinery performance test, tooth harmonic time-frequency characters of first order of three-phase cage asynchronous motor are most important. The MATLAB software is used to make model and simulate the starting characteristic of asynchronous motor in this article, while the stator current signal of starting motor is de noised by wavelet transform. Through decomposition and reconstruction of wavelet transform, the amplitude of fundamental and harmonic wave in de noising stator current can be reduced, and then the tooth harmonic of first order of starting rotor is extracted. Using the excellent time-frequency analyzing characters of wavelet package transform, the tooth harmonic time-frequency curve is fitted.

Mathematical model of operating characteristics of asynchronous motors with frequency control

A method for calcualting the operating characteristics of operated asynchronous motors fed with pulse voltage is presented in the article. Based on this method, a G-shaped equivalent circuit is displayed for each harmonic in which the pressure curve corresponds to the phase of the current. The suggested model takes into consideration the influence of replacing a current on the active resistance of a rotor at higher harmonics, as well as the increase in magnetic losses due to hysteresis and vortical currents.

On the performance characteristics of a synchronous motor fed from a voltage source inverter

Using two axis model the steady state characteristics of a voltage controlled synchronous motor drive are investigated for different modes of operation based on signal flow graph technique. The input voltages are assumed to be quasi square wave. The analysis shows that depending upon the mode employed the machine can be made to possess shunt, series or mixed characteristic. The torque developed is of pulsating nature. All the modes of operation have sixth harmonic pulsations which are roughly 20 percent of the mean value. A voltage fed motor is found to have reduced torque pulsations when compared to a current fed one with the same flux levels.

Improvement of pull‐in characteristics of a synchronous motor by field changeover control

Improvement of pull‐in characteristics of a synchronous motor by field changeover control

Characteristics of a synchronous motor with current-compounded self excitation

It is common practice with synchronous motors to use some form of excitation control to ensure either constant power factor or constant reactive power at all normal loads. The use of a static current-compounded self-excitation circuit for this purpose is explained in the paper. Measurements showing the accuracy of control and the stability limit during steady-state operation are presented, and these are compared with corresponding results for constant excitation. The transient characteristics of the controlled motor are discussed, and the transient stability and the response to a sudden load change are investigated. Reasonably accurate agreement is obtained between measurements and theoretical predictions made from a simple study of an idealised excitation circuit. The possibility of this form of excitation giving rise to sustained rotor oscillations is mentioned, and a possible cure is advanced.

A Novel Type of Smoothly Variable Speed, A-C Motor Having Widely Adjustable Power-Factor Characteristics

In this paper a new type of a-c motor, using d-c excitation to the stator and 2-phase a-c variable voltage to the armature through synchronously revolving brushes, is described. The new machine has smoothly adjustable speed characteristics of a d-c motor and power-factor (pf) control characteristics of a synchronous motor. The motor can also be used in single-phase systems. Again, it is possible to operate the machine with series-and compound-connected excitation in addition to using it as an autosynchronized converter, if additional stationary brushes are provided.

Characteristics and applications of vibration galvanometers

In the vibration galvanometer we have a type of synchronous motor which is distinctly different from all the ordinary types of dynamo electric machines. Further it does not have any of the characteristics of any of the ordinary galvanometers and except for the fact that it is used in the detection or measurement of small currents and voltages, it should not be called a galvanometer. In galvanometers, except when used in the measurement of transient currents or quantity of electricity, the moving system is displaced until we have an equality of static couples acting on it. In the vibration galvanometer the equilibrium condition is an equality between integral values of the product of the current and generated voltage and the mechanical power dissipated in various ways as in ordinary electric motors when operated without a load. It therefore behaves more like an electric motor than like a galvanometer. Further, since it is used only with alternating currents and operates in synchronism with the current it must necessarily have some of the characteristics of a synchronous motor. As a motor the efficiency of conversion was found in a particular case to be as high as 97½ per cent while the power required to maintain an easily discernable amplitude of vibration was of the order of 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−11</sup> watts. One of the large turbo-generators would therefore furnish the power necessary to operate a thousand-million-billion such machines.

Characteristics and Applications of Vibration Galvanometers

In the vibration galvanometer we have a type of synchronous motor which is distinctly different from all the ordinary types of dynamo electric machines. Further it does not have any of the characteristics of any of the ordinary galvanometers and except for the fact that it is used in the detection or measurement of small currents and voltages, it should not be called a galvanometer. In galvanometers, except when used in the measurement of transient currents or quantity of electricity, the moving system is displaced until we have an equality of static couples acting on it. In the vibration galvanometer the equilibrium condition is an equality between integral values of the product of the current and generated voltage and the mechanical power dissipated in various ways as in ordinary electric motors when operated without a load. It therefore behaves more like an electric motor than like a galvanometer. Further, since it is used only with alternating currents and operates in synchronism with the current it must necessarily have some of the characteristics of a synchronous motor. As a motor the efficiency of conversion was found in a particular case to be as high as 97½ per cent while the power required to maintain an easily discernable amplitude of vibration was of the order of 10 −11 watts. One of the large turbo-generators would therefore furnish the power necessary to operate a thousand-million-billion such machines.